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Josh Haner/The New York Times
Last month, Robert Franks, 59, received a CT angiogram at Lenox Hill Hospital in Manhattan.

The New York Times, by Alex Berenson & Reed Abelson — A group of cardiologists recently had a proposition for Dr. Andrew Rosenblatt, who runs a busy heart clinic in San Francisco: Would he join them in buying a CT scanner, a $1 million machine that produces detailed images of the heart?

The scanner would give Dr. Rosenblatt a new way to look inside patients’ arteries, enable his clinic to market itself as having the latest medical technology and provide extra revenue.

Although tempted, Dr. Rosenblatt was reluctant. CT scans, which are typically billed at $500 to $1,500, have never been proved in large medical studies to be better than older or cheaper tests. And they expose patients to large doses of radiation, equivalent to at least several hundred X-rays, creating a small but real cancer risk.

Dr. Rosenblatt worried that he and other doctors in his clinic would feel pressure to give scans to people who might not need them in order to pay for the equipment, which uses a series of X-rays to produce a composite picture of a beating heart.

“If you have ownership of the machine,” he later recalled, “you’re going to want to utilize the machine.” He said no to the offer.

And yet, more than 1,000 other cardiologists and hospitals have installed CT scanners like the one Dr. Rosenblatt turned down. Many are promoting heart scans to patients with radio, Internet and newspaper ads. Time magazine and Oprah Winfrey have also extolled the scans, which were given to more than 150,000 people in this country last year at a cost exceeding $100 million. Their use is expected to soar through the next decade. But there is scant evidence that the scans benefit most patients.

Increasing use of the scans, formally known as CT angiograms, is part of a much larger trend in American medicine. A faith in innovation, often driven by financial incentives, encourages American doctors and hospitals to adopt new technologies even without proof that they work better than older techniques. Patient advocacy groups and some doctors are clamoring for such evidence. But the story of the CT angiogram is a sobering reminder of the forces that overwhelm such efforts, making it very difficult to rein in a new technology long enough to determine whether its benefits are worth its costs.

Some medical experts say the American devotion to the newest, most expensive technology is an important reason that the United States spends much more on health care than other industrialized nations — more than $2.2 trillion in 2007, an estimated $7,500 a person, about twice the average in other countries — without providing better care.

No one knows exactly how much money is spent on unnecessary care. But a Rand Corporation study estimated that one-third or more of the care that patients in this country receive could be of little value. If that is so, hundreds of billions of dollars each year are being wasted on superfluous treatments.

At a time when Americans are being forced to pay a growing share of their medical bills and when access to medical care has become a major political issue for states, Congress and the presidential candidates, health care experts say it will be far harder to hold down premiums and expand insurance coverage unless money is spent more wisely.

The problem is not that newer treatments never work. It is that once they become available, they are often used indiscriminately, in the absence of studies to determine which patients they will benefit.

Some new treatments, like the cancer drug Gleevec and implantable heart defibrillators, undoubtedly save lives, contributing to the United States’ reputation for medical breakthroughs. But others — like artificial spinal disks, which can cost tens of thousands of dollars to implant but have not been shown to reduce back pain in many patients, and Vytorin, a new cholesterol drug that costs 20 times as much as older medicines but has not been proved superior — have been criticized for not justifying their costs.

And sometimes, the new technologies prove harmful. Physicians were stunned, for example, when clinical trials showed last year that expensive anemia medicines might actually hasten death in kidney and cancer patients. Such drugs are used more widely in the United States than elsewhere.

“We have too many situations where we thought we knew what the answer was and it didn’t turn out like everyone thought,” said Dr. Mark Hlatky, a cardiologist and professor of health research and policy at Stanford University.

A Tool of Dubious Value

The problem of inadequate study is especially serious for medical devices and imaging equipment like scanners, which typically are not as strictly regulated as prescription drugs. Under Food and Drug Administration regulations, the makers of CT scanners — CT is short for computed tomography — do not have to conduct studies to prove that their products benefit patients, as drug makers do. The manufacturers must certify only that the scanners are safe and provide accurate images.

Once the F.D.A. approves a test or device, Medicare rarely demands evidence that it benefits patients before agreeing to pay for it. But last year, Medicare officials raised questions about the benefits of CT heart scans and said it would demand more studies before paying for them. But after heavy lobbying by cardiologists, Medicare backed down. Private insurers, while initially reluctant to pay for the tests, are also covering them.

Physicians in this country have a free hand in deciding when to use new technology like CT angiography. Some are conservative. But others, especially doctors in private practice who own their scanners, use the tests aggressively.

Douglas Ring, a 63-year-old Los Angeles real estate developer, said he received a CT heart scan in October 2005, on the advice of Dr. Ronald P. Karlsberg, a Beverly Hills cardiologist. “Ron has been my physician for 15 or 20 years, and he got this new toy in his office, and he said I should try it,” Mr. Ring said. He took the test despite having no symptoms of heart disease, like shortness of breath and chest pain. He was already taking cholesterol medicine, and a different test had shown no problems with his heart.

The CT heart scan by Dr. Karlsberg found a moderate buildup of plaque in one of Mr. Ring’s coronary arteries. The doctor increased Mr. Ring’s cholesterol medicines and encouraged him to diet and exercise.

Dr. Karlsberg said he considered the information from Mr. Ring’s CT scan extremely valuable. “Here’s a case of near-serious coronary disease that required medical management,” said Dr. Karlsberg, a partner at the Cardiovascular Medical Group of Southern California, which conducted about 1,400 CT heart scans last year.

Many other cardiologists, though, say patients like Mr. Ring do not benefit from CT scans. And by the time they are 50, most people will have plaque visible on a CT scan, so the findings of Mr. Ring’s scan were not surprising.

Arteries narrowed by plaque are not necessarily a threat, said Dr. Eric Topol, a practicing cardiologist and director of the Scripps Translational Science Institute in La Jolla, Calif. The danger arises when bits of plaque break and produce a clot that blocks blood to the heart. But CT angiograms cannot tell whether a particular blockage is likely to rupture or, except in extreme cases, is keeping the heart from receiving enough blood.

If doctors do choose to treat blockages, they can insert stents — small metal scaffolds that prop open arteries. But while stents have been proved to reduce chest pain, they have not been shown to prolong patients’ lives or help them avoid heart attacks. Patients with the most severe blockages can receive bypass surgery, which when necessary can be a lifesaving procedure.

And so patients who do not have chest pain, like Mr. Ring, should not receive CT heart scans, said Dr. Rita Redberg, a cardiologist and researcher at the University of California, San Francisco, who is a leading critic of the scans.

“No data suggests that there’s any reason for anyone asymptomatic to have a test,” she said. “There certainly is this idea that having a test can help you prevent a heart attack, and I don’t know where it came from.”

Further, each scan creates an additional lifetime risk of cancer that is somewhere between 1 in 200 and 1 in 5,000, said Dr. David J. Brenner, director of the Center for Radiological Research at Columbia University. Younger patients and women are at higher risk.

Dr. Karlsberg and other cardiologists who support widespread use of CT heart scans argue that they can reduce the need for other tests — like conventional angiograms, which can find plaque but require a catheter to be threaded through the arteries. Conventional angiograms are more expensive than CT scans and carry their own risks.

If a CT heart scan finds plaque that a doctor intends to treat with a stent, a conventional angiogram will still be necessary to determine where and how to implant the stent. So a CT scan does not always eliminate the need for a conventional angiogram.

The most valuable use of a CT angiogram may be when a patient comes to an emergency room complaining of chest pains but has few other symptoms of a heart attack. The test can quickly rule out heart trouble. But such patients represent a minority of those receiving CT heart scans.

Dr. Karlsberg also pointed to the case of a seemingly healthy 68-year-old patient whom he scanned in his office in 2006. To the shock of both doctor and patient, the scan revealed a 95 percent blockage of the patient’s main coronary artery. The patient had immediate bypass surgery to relieve the blockage, an operation that may have saved his life, Dr. Karlsberg said. The man, who cited privacy concerns in asking that his name not be used, confirmed the doctor’s account.

Cardiologists who oppose wide use of the scans agree that they can sometimes find dangerous blockages that require immediate surgery in asymptomatic patients. But they said such cases are extremely rare — not common enough to justify using the scans routinely, given their cost and radiation risks.

For too many people, the scans are simply inappropriate, said Dr. Howard C. Herrmann, director of interventional cardiology at the University of Pennsylvania. “I find many patients have CT angiograms who shouldn’t be getting CT angiograms.”

As more than 13,000 heart doctors gathered in Chicago in late March for the annual American College of Cardiology conference, the biggest and best-located booths belonged to General Electric, Philips Electronics, Siemens and Toshiba, the leading makers of the machines used for CT angiograms.

Cardiologists hired by the companies offered short briefings on ways to reduce radiation doses, while sales representatives in business suits quietly talked up the benefits of the scans and the clarity of the images. The sales atmosphere was low key, more art gallery than “Glengarry Glen Ross.”

A hard sell is unnecessary because the manufacturers are finding a receptive audience. Many cardiologists have been eager for a new tool that lets them see inside the heart with unprecedented clarity — while also providing a new source of revenue.

Use of CT scans accelerated after 2004, when manufacturers introduced a new generation called 64-slice scanners, which are fast enough to capture images of a beating heart. The scanners fire X-rays in a series of rotations around the torso, generating thousands of narrow vertical images. Sophisticated software then combines data from the X-rays into a single image.

The Financial Incentives

Already, more than 1,000 hospitals and an estimated 100 private cardiology practices own or lease the $1 million CT scanners, which can be used for the angiograms and for other imaging procedures. Once they have made that investment, doctors and hospitals have every incentive to use the machines as often as feasible. To pay off a scanner, doctors need to conduct about 3,000 tests, industry consultants say.

Fees from imaging have become a significant part of cardiologists’ income — accounting for half or more of the $400,000 or so that cardiologists typically make in this country, said Jean M. Mitchell, an economist at Georgetown University who studies the way financial incentives influence doctors.

Besides generating profits themselves, the scans enable cardiologists to find blockages in patients who have no symptoms of heart problems. Doctors can then place stents in patients who would not otherwise have received them, generating additional revenue of $7,500 to $20,000 per patient.

While clinical trials have not shown that stents benefit patients with no symptoms of heart disease, they are still routinely inserted in such patients when tests find significant blockages. Cardiologists joke that the phenomenon is “ocular stenosis” — blockages that can be seen are stented.

“You find a lot of asymptomatic disease,” said John O. Goodman, a business consultant to cardiologists. “It will put more patients in the cath lab” — medical shorthand for a cardiac catheterization laboratory, where conventional angiograms and stenting procedures take place.

Ms. Mitchell said cardiologists simply practice medicine the way the health system rewards them to. Given the opportunity to recommend a test for which they will make money, the doctors will.

“This is not greed,” she said. “This is normal economic behavior.”

Doctors who perform a lot of CT heart scans tend to be evangelists for the technology. Dr. John A. Osborne, a cardiologist in solo practice in Grapevine, Tex., just outside Dallas, argues that CT angiograms catch heart disease at its earliest stages. His Web site, sothcardiology.com, states the proposition in stark terms: “Half of Americans have died of heart attacks and strokes. Which one are you?”

Supported by a staff of about 20 people, Dr. Osborne estimates that he does 15 CT angiograms a day. Arterial plaque is “cancer of the coronaries,” he tells patients. “Do you have it or not?”

Before their plaque creates symptoms, Dr. Osborne asserts, patients should be aggressively treated, urged to diet and exercise and given cholesterol-lowering and other drugs.

Scans ‘Sell Themselves’

Like many cardiologists who perform CT scans, Dr. Osborne relies on primary-care doctors to send him candidates. He frequently gives lectures to primary-care doctors on the technology’s benefits. When doctors see the images, he said, “they become true believers.”

Two years ago, Dr. Osborne persuaded a family practice doctor, Dr. Michael Dotti, to have his own CT angiogram at no cost. Dr. Dotti was amazed at the scan’s ability to spot early signs of disease. “It’s nice to know I have clear arteries at 51,” he said. “The scans sort of sell themselves.”

The technology has been covered in the news media, including a September 2005 Time magazine cover on CT angiograms, “How New Heart-Scanning Technology Could Save Your Life.” The following month, Oprah Winfrey devoted a segment of her television program to women’s heart disease and recommended that her viewers consider taking the test. Representatives for Time and Ms. Winfrey declined to comment on their coverage of the technology.

Even cardiologists who think the CT scans are overused say they may one day prove valuable. If manufacturers can produce scanners that can determine which plaques are stable and which are likely to rupture, the machines could revolutionize the treatment of heart disease. Patients found to be at low risk might be able to avoid taking medicine entirely, while others would be given intensive treatment.

But for now, doctors cannot use the images that way. Finding out whether the heart is actually short of blood and at high risk for an attack requires tests other than a CT scan — most likely, a nuclear stress test, which uses radioactive dye to track blood flow through the coronary arteries.

The CT angiogram is “a great technology searching for a great application,” said Dr. Charanjit S. Rihal, the director of the cardiac catheterization laboratory at the Mayo Clinic in Rochester, Minn., who sees little diagnostic value in the current generation of heart scanners.

CareCore National, a Bluffton, S.C., company that reviews treatment and test requests for health insurers, has found that when doctors request a CT angiogram for a patient, they also frequently ask for a nuclear stress test.

“We’re seeing layering of tests on top of each other,” said Dr. Russell Amico, a CareCore executive. His company denies as many as 70 percent of the CT scans requested, a much higher rate of rejection than for other kinds of tests his company reviews.

Impatient Patients

Sometimes, it is not the doctor but the patient who is eager for the scan. On a recent Wednesday morning on the Upper East Side of Manhattan, Dr. Harvey Hecht at Lenox Hill Hospital watched from a lead-shielded control room as a 59-year-old patient, Robert Franks, underwent a CT angiogram.

Mr. Franks has a family history of cardiac disease, and his father and two uncles died of heart attacks. But Mr. Franks, director of corporate security for Time Inc., is in excellent shape. He works out daily and takes two cholesterol-lowering medicines. The drugs have reduced his LDL, or bad, cholesterol to 60, a remarkably low level.

Nonetheless, in February, Mr. Franks took a test called a calcium score, which measures the amount of calcified plaque in the arteries. The test, a less extensive form of scanning, revealed a moderate buildup of calcium in his arteries, a potential sign of heart disease.

So he decided to have a nuclear stress test. When that test showed no problem, the cardiologist who conducted it said he did not need more testing.

But Mr. Franks was still not satisfied. “I’m someone who wants to know,” he said.

After doing research on the Internet, he found Dr. Hecht, who recommended a CT angiogram. Dr. Hecht acknowledged that Mr. Franks probably did not have severe heart disease. But he said the scan would be valuable anyway because it might reassure him. And his insurance would cover the cost.

A CT scanner is 8 feet high by 8 feet wide and 2 feet deep, with a doughnut-shaped hole at its center. Wearing a hospital gown, Mr. Franks lay on a table attached to the machine and was injected with a drug to lower his heart rate, along with a contrast dye to improve the quality of the images from the test. (Mr. Franks later compared the warmth he felt after the injection of the dye to “the first sip of a well-blended martini.”)

In the control room, Salvatore Fevola, the manager of the CT scanning equipment at Lenox Hill, instructed Mr. Franks, who was raising his hands over his head, to hold his breath as the table moved through the machine.

Twelve seconds later, the test was complete, and the machine’s software began to assemble information from thousands of images into a single coherent picture of Mr. Franks’s heart.

A few minutes later, Dr. Hecht studied the results. As he had expected, the angiogram revealed that Mr. Franks’s arteries were healthy. In some places, plaque had blocked 25 percent of their blood flow, but in general, cardiologists do not consider blockages clinically relevant until they reduce blood flow at least 70 percent.

After Mr. Franks finished dressing, he joined Dr. Hecht, who went over the results, explaining that his heart appeared healthy and that he would not need a stent. Still, Dr. Hecht recommended that Mr. Franks have another CT angiogram next year to check that the plaque was not thickening. Mr. Franks agreed, pronounced himself satisfied and left.

For Mr. Franks, the test was quick and painless. But it subjected him to a significant dose of radiation.

Based on a reporter’s notes about the duration of the scan and the power output reported by the scanner, Dr. Brenner of the Center for Radiological Research estimated that Mr. Franks had received 21 millisieverts of radiation — even more than a typical test, equal to about 1,050 conventional chest X-rays.

Given the radiation risks, Dr. Ralph Brindis, another cardiologist, said Dr. Hecht had erred. Because Mr. Franks had already taken a nuclear stress test with normal results, he did not need a CT angiogram, said Dr. Brindis, vice president of the American College of Cardiology. And particularly because the scan’s results were benign, he said, Dr. Hecht should not have recommended a follow-up test.

“The biggest problem we have with radiation is that the doses are cumulative and additive,” Dr. Brindis said. “So the concept of doing serial CT testing on asymptomatic patients, I think, is abhorrent. I cannot justify that.”

Dr. Hecht said he sharply disagreed with Dr. Brindis. The scan was appropriate for Mr. Franks, despite his normal results from the nuclear stress test, because of Mr. Franks’s other risk factors for heart disease, including his higher-than-average calcium score, Dr. Hecht said. And he said he recommended a follow-up scan next year so he could see how quickly the plaque in Mr. Franks’s arteries was thickening.

Otherwise, “how do we know that our therapy is effective?” Dr. Hecht said. He acknowledged that many cardiologists do not favor repeat scans but said long-term radiation risks were a relatively minor issue for patients 60 and older.

Cardiologists like Dr. Brindis hurt their patients by being overly conservative and setting unrealistic standards for the use of new technology, Dr. Hecht said.

“It’s incumbent on the community to dispense with the need for evidence-based medicine,” he said. “Thousands of people are dying unnecessarily.”

Medicare’s Scrutiny

The Centers for Medicare and Medicaid Services had decided to push back.

The agency, which this year will spend more than $800 billion on health care, rarely questions the need to pay for new treatments. But last June, Medicare said it was considering paying for CT heart scans only on the condition that studies be done to show they had value for patients.

Concerned about the overall proliferation of imaging tests, Medicare said it might require a large-scale study to determine the scans’ value.

The plan met with fierce resistance, particularly from a relatively new organization of specialists, the Society of Cardiovascular Computed Tomography. The society has 4,700 physician members and one purpose — to promote CT angiograms.

“For the CT society, this was life or death,” said Dr. Daniel S. Berman, the group’s president-elect. “This decision could essentially put them out of business.”

Galvanized, at a meeting in November in Chicago, the CT specialists vowed to overturn any possible Medicare proposal.

“We didn’t need to be talking about registries and the research,” Dr. Berman said. “We needed to be questioning the wisdom of the Medicare decision itself.”

The next month, Medicare issued the draft of its proposal, saying that it would pay for the scans only if a large-scale study were conducted. The CT society, along with other prominent medical groups whose members performed scans, set to work lobbying the agency and members of Congress.

One group marshaled the evidence the doctors would take to Medicare, arguing that the agency had ignored some studies, including those of the new 64-slice CT scans. Another group visited Congressional offices. Defenders of the technology argued that Medicare had agreed to pay for other tests, like mammograms, without requiring proof that they improved patient care. Breakthrough technologies, they said, need time to prove themselves.

Medicare “set the bar so high, no new technology would be able to survive,” said Dr. Michael Poon, a New York cardiologist who is the CT society’s current president.

Cardiologists met with Representative Carolyn McCarthy, a New York Democrat. In March, she and other members of Congress wrote to Medicare, urging it to reconsider its plan. Eventually, a dozen or so senators and 79 representatives lined up to support the society’s efforts.

And Medicare gave way.

“There are a lot of technologies, services and treatments that have not been unequivocally shown to improve health outcomes in a definitive manner,” Dr. Barry Straube, Medicare’s chief medical officer, explained when announcing that the agency would keep covering the tests.

In other words, the lack of evidence that the CT scans provide measurable medical benefit would not stop Medicare from paying for them.

Heavy lobbying makes it virtually impossible for the agency to insist on more evidence before agreeing to pay for a new technology, said Dr. James Adamson, chief medical officer for Arkansas Blue Cross and Blue Shield. “Medicare,” he said, “does not make a lot of really hard decisions.”

In a subsequent interview, Marcel Salive, a Medicare official, said the agency still hoped for large-scale studies to demonstrate the value of CT scans.

The technology’s proponents say they understand the need to prove its value. “It’s incumbent on us to do more work,” said Gene Saragnese, vice president for molecular imaging and CT at General Electric.

Doctors are also discussing the creation of registries to track patients who have had CT angiograms. But now that Medicare has backed down, skeptics say it is unlikely that anyone will conduct a major clinical trial to determine if patients who receive CT heart scans have better medical outcomes than those who do not.

“It’s clearly going to be much more difficult, given the Medicare decision,” said Dr. Sean Tunis, a former Medicare official who directs the Center for Medical Technology Policy, a nonprofit group.

Industry consultants say that now that Medicare has agreed to pay for the tests, resistance among commercial insurers is likely to disappear. “I believe the holdouts will be paying within 12 months,” said Michelle Boston, the chief executive of Partners Imaging, a Dallas company that works with doctors to offer CT scans.

And so CT angiograms seem destined to continue, in ever greater numbers. “Once the train leaves the station, once the technology gets on the marketplace, we don’t get the evidence,” said Dr. Redberg, the University of California, San Francisco, cardiologist. “We’re spending a lot of money on technology of unclear benefit and risk.”

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64-Slice CT technology revolutionizes heart attack prevention

Cardiac CT Angiography (CTA) is a new and revolutionary way to non-invasively visualize the inside of the coronary arteries. With the latest advances in high resolution scanning, the Siemens Sensation 64-Slice CT Scanner can create amazingly detailed and accurate images of the heart, lungs, and arteries in just seconds. That means easier, painless diagnosis of the cause of symptoms and earlier detection of developing problems before symptoms have started.

CT Angiography vs Cardiac Catheterization:

Until now, Cardiac Catheterization has been the most important tool for evaluating the arteries of the heart. But, Cardiac Catheterization is an invasive procedure that requires an incision in the groin, inserting a catheter into an artery in the leg and advancing the catheter under X-ray guidance to the heart. Contrast dye is then injected directly into the arteries on the surface of the heart and X-rays are taken that show whether any of the vessels are narrowed.

Cardiac CT Angiography requires only a small IV in vein of the arm. A small amount of dye is injected into the vein followed by a 10 second CT scan of the heart.

With Cardiac CT Angiography there is no risk of vascular damage, heart attack or stroke.

After the scan, the IV is removed and you can go home, to work, or resume your normal activities immediately.

Avoiding Invasive Tests with Cardiac CT Angiography:

Cardiac CT Angiography can accurately exclude the presence of significant blockage in the coronary arteries. Nearly 1 out of every 3 people advised to have a Cardiac Catheterization ultimately find they do not have any have significantly blocked arteries. Cardiac CT Angiography can be an excellent way to avoid the risk of complications and eliminate the need for a stay in the hospital.

Cardiac CT Angiography is a highly accurate alternative to Cardiac Catheterization for those people who have an abnormal stress test but are unlikely to have significant heart disease. In people with non-diagnostic (equivocal or borderline) stress tests, or those with “negative” stress tests but who are at high risk of coronary artery disease, Cardiac CT Angiography can quickly and non-invasively determine whether significant coronary artery disease is present. If you have an elevated Coronary Calcium Score, a Cardiac CT Angiography can be used to determine the severity of narrowing of the arteries.

Insurance Coverage:

Cardiac CT Angiography is covered by Medicare and by many private health plans.

Cardiac CT Angiography and radiation:

A typical Cardiac CT Angiography will expose patients to about 8-12 mSv of radiaiton. A Nuclear Stress Test is typically 12-25 mSv of radiation exposure. The annual natural exposure to radiation from the environment is about 3.5 mSv. While it is important to minimize unnecessary radiation exposure as much as possible, the radiation exposure from a Cardiac CT Angiography is not different from other commonly used medical tests.

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I. Decision

The Centers for Medicare and Medicaid Services (CMS) has decided to make no change to section 220.1 of the National Coverage Determination Manual titled “Computed Tomography” (Pub. 100-3, 220.1). We have decided that no national coverage determination on the use of cardiac computed tomography angiography for coronary artery disease is appropriate at this time and that coverage should be determined by local contractors through the local coverage determination process or case-by-case adjudication.

II. Background

Computed tomographic angiography (CTA) is a general phrase used to describe noninvasive imaging of the arteries with various types of computed tomography (CT) machines, such as multislice CT (MSCT), multidetector CT (MDCT), and dual source CT (DSCT).

The use of CTA has increased over the years due to advances in the technology and rapid diffusion of the machines outside the hospital settings. The initial single slice CT machines produced poor quality images. In the late 1990’s, 4 slice CT machines were introduced, with 16 slice and 64 slice CT machines following shortly afterwards. Image quality and performance reportedly increased with each model. However, questions remain on the indications for use.

A particular focus has been the use of CTA for evaluation of the coronary arteries in patients with chest pain. Proponents have claimed that cardiac or coronary CTA may reduce the need for invasive coronary angiography for certain patients. Critics have pointed out the lack of evidence on outcomes and the limitations to the technology including uninterpretable/unassessable segments and the health risks from the considerable radiation exposure. Although there are other uses of CTA, this decision focuses only on the use of CTA for the evaluation of the coronary arteries in patients with symptomatic coronary artery disease (e.g., chest pain). Imaging performed on patients without chest pain (asymptomatic patients) would be considered screening and is not an available benefit in the Medicare program.

Chest pain (angina pectoris) can be classified as “typical angina, atypical angina and noncardiac chest pain” (Snow, 2004 – Appendix A). Angina is defined “as a clinical syndrome characterized by discomfort in the chest, jaw, shoulder, back, or arm” (Snow, 2004). Unstable angina is defined as “angina that presents in 1 of 3 principal ways: rest angina, severe new-onset angina, or increasing angina” (Snow, 2004).

Given the prevalence and incidence of CAD in the US, angina has been well studied and evidence-based guidelines are available for unstable and stable angina. The ACC/AHA guidelines on unstable angina (Gibbons, 2007) and chronic stable angina (Gibbons, 2002) are such examples and are well recognized and accepted. Although these guidelines do not directly incorporate coronary CTA, the treatment algorithms provide clues on possible scenarios where CTA may be considered.

For unstable angina, patients who are at high or intermediate short term risk of death (Appendix A) are almost always treated as inpatients in the hospital setting. These patients typically undergo cardiac catheterization and invasive coronary angiography so the role of CTA is very limited (Anderson, 2007). However, “low-risk patients with unstable angina have a short-term risk not substantially different from those with stable angina” and “their evaluation can be accomplished safely and expeditiously in an outpatient setting” (Gibbons, 2002). Risk in patients with unstable angina may be estimated using validated methods such as the TIMI risk score (Antman, 2000) as noted in the ACC/AHA guidelines (Appendix A).

For chronic stable angina, the ACC/AHA and ACP have developed guidelines with treatment algorithms that may also help guide the consideration for use of imaging such as coronary CTA (Gibbons, 2002). Specifically, for patients with chronic stable angina and an intermediate probability of CAD, imaging may be considered when the exercise test does not suggest high risk and there is inadequate information on diagnosis (Appendix A). The guidelines provide a narrow window for the use of imaging. The current recommended approach for risk determination in patients with stable chest pain is based upon the results of exercise testing. The pretest probability of CAD may be determined by several validated methods (Appendix A) such as published models by Diamond and Forrester (1979), Mark (1987) and Pryor (1993).

Appropriateness criteria have also been published (Hendel, 2006). While these were based on consensus, the criteria may provide additional information on specific uses of CTA, especially for those indications which were considered inappropriate. Most studies, as noted in the Blue Cross Blue Shield technology assessments, have not specifically evaluated long term health outcomes but have looked at diagnostic test characteristics and test performance compared to invasive angiography. The question of how coronary CTA may fit into the current recommended clinical pathways needs to be addressed by research and clinical experts.

In addition, there are a number of aspects or dimensions of imaging quality, as noted by Douglas and colleagues (Douglas et al., 2006), that are relevant and applicable to coronary CTA. Many of these aspects are implicit in the process of imaging but being such may be areas that deserve some explicit focus to ensure that quality is maintained and not forgotten in everyday practice.

III. History of Medicare Coverage

Medicare has an NCD, last revised in 1985, that discusses general uses of CT. The policy does not specifically address the use of CTA technology or CT for the diagnosis of CAD as such an indication was not in clinical practice at the time the policy was last updated. Therefore, CTA has never been addressed through national policy and in the absence of national policy that addresses CTA, coverage is at the discretion of local Medicare contractors. The majority of local contractors have similar local coverage determination policies (LCDs) on CTA.

Medicare is a defined benefit program (§ 1812 (Scope of Part A); § 1832 (Scope of Part B) § 1861(s) (Definition of Medical and Other Health Services)). An item or service must fall within a benefit category as a prerequisite to Medicare coverage. CTA may be eligible for coverage under the Social Security Act section 1861(s)(3).

IV. Timeline of Recent Activities

Date Action

June 13, 2007 CMS opens National Coverage Analysis for CTA.

July 13, 2007 Initial 30-day public comment period ends.

December 13, 2007 CMS posts proposed decision. A second 30-day public comment period begins.

January 12, 2008 The second 30-day public comment period ends.

V. FDA Status

Currently, CT imaging systems and post-processing software go through the 510(k) process at the FDA to obtain clearance for commercial distribution. To obtain 510(k) clearance, the sponsor must demonstrate that the device is substantially equivalent to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act) that do not require approval of a premarket approval application (PMA). Below are examples of two CT related devices (one CT scanner and one software system) cleared by the FDA through the 510(k) process. The indications for use were copied from the FDA’s 510(k) online database at http://www.fda.gov/cdrh/pdf7/K071806.pdf and http://www.fda.gov/cdrh/pdf6/K062386.pdf respectively.

Device Name: ECLOS Computed Tomography X-ray System
Clearance Dated: August 28, 2007
The ECLOS Computed Tomography system is an x-ray imaging device that produces cross-sectional images of the body at different angles. The system reconstructs, processes, displays, and stores the collected images. The device output can provide an aid to diagnosis when used by a qualified physician and is intended for general purpose CT applications.

Device Name: QAngio CT
Clearance Dated: October 5, 2006
QAngio CT software solution has been developed for the objective and reproducible analysis of vessels in CTA images. It enables the quantitative analysis of CT angiograms based on automated segmentation. More specifically, QAngio CT can be used to quantify a number of lesion characteristics. QAngio CT is intended for use as an auxiliary tool in assessing CTA studies in clinical practice and in clinical trials. The analysis results obtained with QAngio CT are to be interpreted by cardiologists and radiologists.

VI. General Methodological Principles

When making national coverage decisions, CMS evaluates relevant clinical evidence to determine whether or not the evidence is of sufficient quality to support a finding that an item or service falling within a benefit category is reasonable and necessary for the diagnosis or treatment of illness or injury or to improve the functioning of a malformed body member. The critical appraisal of the evidence enables us to determine to what degree we are confident that: 1) the specific assessment questions can be answered conclusively; and 2) the intervention will improve health outcomes for patients. An improved health outcome is one of several considerations in determining whether an item or service is reasonable and necessary.

A detailed account of the methodological principles of study design that the agency utilizes to assess the relevant literature on a therapeutic or diagnostic item or service for specific conditions can be found in Appendix B. In general, features or clinical studies that improve quality and decrease bias include the selection of a clinically relevant cohort, the consistent use of a single good reference standard, and the blinding of readers of the index test, and reference test results.

Public comments sometimes cite the published clinical evidence and give CMS useful information. Public comments that give information on unpublished evidence such as the results of individual practitioners or patients are less rigorous and therefore less useful for making a coverage determination. Public comments that contain personal health information will not be made available to the public. CMS uses the initial public comments to inform its proposed decision. CMS responds in detail to the public comments on a proposed decision when issuing the final decision memorandum.

VII. Evidence

A. Introduction

In this coverage analysis, we considered coronary CTA studies and evidence that were published after the BCBS TEC assessments (published in 2005 and 2006), since the indications are similar. We considered the evidence in the hierarchical framework of Fryback and Thornbury (1991) where Level 2 addresses diagnostic accuracy, sensitivity, and specificity of the test; Level 3 focuses on whether the information produces change in the physician’s diagnostic thinking; Level 4 concerns the effect on the patient management plan and Level 5 measures the effect of the diagnostic information on patient outcomes. Most studies have focused on test characteristics and have not considered health outcomes, such as mortality, morbidity or reduction of invasive angiography. We believe that health outcomes are more important than test characteristics. In evaluating diagnostic tests, Mol and colleagues (2003) reported: “Whether or not patients are better off from undergoing a diagnostic test will depend on how test information is used to guide subsequent decisions on starting, stopping, or modifying treatment. Consequently, the practical value of a diagnostic test can only be assessed by taking into account subsequent health outcomes.” When a proven, well established association or pathway is available, intermediate health outcomes may also be considered. For example, if a particular diagnostic test result can be shown to change patient management and other evidence has demonstrated that those patient management changes improve health outcomes, then those separate sources of evidence may be sufficient to demonstrate positive health outcomes from the diagnostic test.

1. Literature Search

CMS searched PubMed from 2005 to present. General keywords included computed tomographic angiography, CTA and coronary. Initially, we searched for studies that presented original data, examined health outcomes and were published in peer-reviewed English language journals. Since only one study met these criteria, the search was expanded to included technology assessments, meta-analysis, reviews, and studies that reported only test characteristics compared to invasive coronary angiography. Abstracts were excluded.

B. Discussion of evidence reviewed

1. Evidence Questions

1. Is the evidence sufficient to conclude that cardiac CTA has the ability to diagnose or exclude coronary artery disease as well as invasive coronary angiography?
2. Is the evidence sufficient to conclude that cardiac CTA reduces the need for invasive coronary angiography?
3. Is the evidence sufficient to conclude that the use of cardiac CTA improves health outcomes for patients with acute chest pain who present in the emergency room or other settings?

2. External technology assessments

DHHS Agency for Healthcare Research and Quality. Non-Invasive Imaging for Coronary Artery Disease. AHRQ 2006; available at: http://www.cms.hhs.gov/determinationprocess/downloads/id34TA.pdf [PDF, 251KB].

In 2006, the Agency for Healthcare Research and Quality commissioned a technology assessment on non-invasive imaging for CAD that was performed by Matchar and colleagues at the Duke Evidence-based Practice Center. For CTA, the authors of the assessment noted: “We identified 29 studies using 16-array or greater multi-detector computed tomography (MDCT) assessing coronary CTA for evaluation of native coronary arteries stenosis, and 13 MRA studies evaluating native coronary artery stenosis using more recent MRI imaging sequences. These studies were generally small, performed at single centers, and often did not include information that would serve to provide confident assessments of the key questions. In particular, we did not identify any studies evaluating the clinical impact of diagnostic strategies including NITs [non-invasive imaging tests] of coronary anatomy compared with strategies that did not include these techniques. The populations studied tended to be relatively young (<65 years of age), and limited results subgrouped by age were available.”

They concluded: “At present, there is limited evidence regarding test performance of NITs for identifying, quantifying, or otherwise characterizing coronary artery stenoses. The available evidence provides preliminary data on the ability of coronary MRA (1.5 T) and coronary CTA using at least 16-array MDCT technology to detect obstructive coronary artery lesion in the proximal to mid coronary arteries. The evidence regarding detection of coronary lesions in branch vessels or distal coronary arteries remains unclear and may well improve as the technology improves. Studies conducted to date primarily fall into the “proof of concept” category with study patients having a high pre-test probability of CAD. Patients providing suboptimal images were often excluded from calculations of test accuracy. Future work will need to examine these tests in larger, less selected populations representing the clinical settings in which they are actually expected to be used. The effect of biases in selection of study patients and in the publication of accuracy results for these tests was not assessed in this preliminary analysis.”

Blue Cross Blue Shield Technology Evaluation Center. Contrast-enhanced cardiac computed tomographic angiography in the diagnosis of coronary artery stenosis or for evaluation of acute chest pain. TEC Assessment Program, Volume 20, No. 4, May 2005.

In 2005, the BCBS TEC published a technology assessment “to evaluate the clinical effectiveness of contrast-enhanced cardiac computed tomographic angiography, hereafter referred to as CTA, for coronary artery evaluation.” Study inclusion criteria were (quoted as follows):

* Used contrast-enhanced EBCT with slice thickness no greater than 1.5 mm or contrast- enhanced MDCT with at least 16 rows
* Applied an appropriate reference standard such as conventional coronary angiography or clinical reference standard
* Reported sensitivity and/or specificity of CTA or sufficient data to generate a 2 × 2 contingency table
* Included only human subjects
* Published in English as a full-length, peer-reviewed journal article

Twenty-one studies (16 on MDCT, 6 on EBCT; 1016 total patients) were included in the assessment. The TEC reported:” The evidence is insufficient to determine whether the use of CTA improves net health outcome or whether it is as beneficial as any established alternatives.”

The TEC criteria and results were as follows:
1. The technology must have final approval from the appropriate governmental bodies. (Met)
2. The scientific evidence must permit conclusions concerning the effect of the technology on health outcomes. (Not met)
3. The technology must improve the net health outcome. (Not met)
4. The technology must be as beneficial as any established alternatives. (Not met)
5. The improvement must be attainable outside the investigational settings. (Not met)
They concluded that: “the use of contrast-enhanced cardiac CT angiography for screening or diagnostic evaluation of the coronary arteries does not meet the TEC criteria.”

Blue Cross Blue Shield Technology Evaluation Center. Contrast-enhanced cardiac computed tomographic angiography in the diagnosis of coronary artery stenosis or for evaluation of acute chest pain. TEC Assessment Program, Volume 21, No. 5, August 2006.

In 2006, the BCBS TEC published an update of their 2005 assessment of CTA. The objective was “to determine the usefulness of CTA as a substitute for coronary angiography for two indications: 1) in the diagnosis of coronary artery stenosis, and 2) in the evaluation of acute chest pain in the emergency room (ER).” The TEC report focused on “studies examining 64-row CTA, which provides better resolution than the previous generation of 16-row machines.” For CTA as a substitute for invasive angiography, study inclusion criteria were (quoted as follows):

* Used contrast-enhanced EBCT with slice thickness no greater than 1.5 mm or contrast- enhanced MDCT with at least 32 rows
* Applied the reference standard of invasive angiography to all patients
* Reported sensitivity and/or specificity of CTA or sufficient data to generate a 2×2 contingency table
* Included only human subjects
* Published in English as a full-length, peer-reviewed journal article

For CTA in the ER; “prospective studies were selected in which patients meeting specific chest pain and clinical criteria for evaluation with CTA were chosen to have the test.”

Seven studies (480 patients) were evaluated for CT diagnostic accuracy, and 2 studies (100 patients) for CTA in the ER. The TEC reported: “The available evidence is inadequate to determine whether CTA improves the net health outcome or is as beneficial as established alternatives for diagnosis of coronary artery stenosis or for evaluation of acute chest pain in the ER.”
The TEC criteria and results were as follows:
1. The technology must have final approval from the appropriate governmental bodies. (Met)
2. The scientific evidence must permit conclusions concerning the effect of the technology on health outcomes. (Not met)
3. The technology must improve the net health outcome. (Not met)
4. The technology must be as beneficial as any established alternatives. (Not met)
5. The improvement must be attainable outside the investigational settings. (Not met)
They concluded: “CTA as a substitute for coronary angiography in the diagnosis of coronary artery stenosis does not meet the TEC criteria. CTA in the evaluation of acute chest pain in the emergency room also does not meet the TEC criteria.”

3. Internal technology assessments

Meta-Analyses

Hamon M, Biondi-Zoccai G, Malagutti P, et al. Diagnostic performance of multislice spiral computed tomography of coronary arteries as compared with conventional invasive coronary angiography. A meta-analysis. J Am Coll Cardiol 2006;48:1896 –1910.

In 2006, Hamon and colleagues reported the results of a meta-analysis “to define the current role of multislice spiral computed tomography (MSCT) for the diagnosis of coronary artery disease (CAD) using a meta-analytic process.” The authors included 29 studies (2024 patients), published from 2002 to 2006, that evaluated the coronary arteries using both CTA (at least 16 slice) and conventional coronary angiography. Study inclusion criteria were: “1) it used MSCT as a diagnostic test for obstructive CAD, with >50% diameter stenosis selected as the cut-off criterion for significant CAD, using conventional invasive angiography as the reference standard; 2) it used the newest generation of MSCT ( >16 slices); and 3) it reported cases in absolute numbers of true positive (TP), false positive (FP), true negative (TN), and false negative (FN) results or presented sufficiently detailed data for deriving these figures.” Exclusion criteria were studies performed: “1) only in patients after coronary artery bypass graft surgery; 2) after percutaneous coronary intervention for long-term stent patency assessment; 3) in a subset of patients with prior heart transplant; or 4) with fewer than 30 enrolled patients.” Patient symptomatology was not specified. A random-effects model was used for the analysis.

The authors noted a considerable percentage of uninterpretable segments that were excluded from the analysis by the study investigators. Pooled sensitivity, specificity, positive and negative predictive values per-segment were 81%, 93%, 67.8% and 96.5%, respectively, and per patient were 96%, 74%, 83% and 94%, respectively.

The authors concluded: “Multislice spiral computed tomography has shortcomings difficult to overcome in daily practice and, at the more clinically relevant per-patient analysis, continues to have moderate specificity in patients with high prevalence of CAD. Studies evaluating the diagnostic performance of the newest generation of MSCT, including patients with low to moderate CAD prevalence, will be critical in establishing the clinical role of this emerging technology as an alternative to CA.”

Schuijf JD, Bax JJ, Shaw LJ, et al. Meta-analysis of comparative diagnostic performance of magnetic resonance imaging and multislice computed tomography for noninvasive coronary angiography. Am Heart J 2006;151:404- 11.

In 2006, Schuijf and colleagues reported the results of a meta-analysis “to clarify the current accuracy of both modalities in the detection of significant coronary artery lesions (compared to conventional angiography as the gold standard).” The authors included 24 studies (1300 patients), published from 2001 to 2005, that compared MSCT (4 to 16 slice) to invasive coronary angiography in patients with known or suspected CAD. Reports with insufficient data to calculate sensitivity and specificity were excluded. Meta-analysis model was not specified. Summary odds ratios were calculated using the “Comprehensive Meta Analysis” program. The authors reported pooled test parameters as follows: sensitivity 85%, specificity 95%, PPV 76% and NPV 97%. They concluded: “Meta-analysis of the available studies with MRI and MSCT for noninvasive coronary angiography indicates that MSCT has currently a significantly higher accuracy to detect or exclude significant coronary artery disease.”

Sun Z, Jiang W. Diagnostic value of multislice computed tomography angiography in coronary artery disease: A meta-analysis. European Journal of Radiology 2006;60:279–286.

In 2006, Sun and Jiang reported the results of a meta-analysis to determine “the diagnostic value of multislice CT (MSCT) angiography in the detection of coronary artery disease (CAD) when compared to conventional coronary angiography.” The authors included 47 studies (3149 patients), published from 2001 to 2006, that studied at least 4 slice CT. Study inclusion criteria were: “(a) patients undergoing both MSCT angiography and coronary angiography examinations; (b) studies included at least 10 patients; (c) assessment or comparison of MSCT angiography with coronary angiography was focused on the visualization of coronary arteries and detection or exclusion of coronary artery stenosis; (d) diagnostic value of MSCT angiography was addressed when compared to coronary angiography in terms of sensitivity, specificity, either segments-, vessels- or patients-based assessment.” Exclusion criteria, study types, patient symptomatology and setting were not specified. Model for analysis was not specified.

The authors reported pooled sensitivities and specificities for 4, 16 and 64 slice CT in the detection of CAD (76%, 93%; 82%, 95%; 92%, 94%; respectively). They concluded that: “MSCT angiography has potential diagnostic accuracy in the detection of CAD. Diagnostic performance of MSCT angiography has been significantly improved with the latest 64-slice CT, with resultant high qualitative and quantitative diagnostic accuracy. 16-slice CT was limited in spatial resolution which makes it difficult to perform quantitative assessment of coronary artery stenoses.”

Systematic Reviews

Janne d’Othee B, Siebert U, Cury R, et al. A systematic review on diagnostic accuracy of CT-based detection of significant coronary artery disease. European Journal of Radiology 2007, in Press.

In 2007, Janne d’Othee and colleagues reported the results of a systematic review to estimate sensitivity and specificity of various imaging modalities. Studies were included if they “used contrast-enhanced CT as a diagnostic test, evaluated native coronary arteries, used catheter-based coronary angiography (CCA) as a reference standard independently of CT findings, reported raw data (i.e., numbers that allowed recalculation of 2×2 contingency tables), and were published in peer reviewed journals.” Coronary artery bypass graft and coronary stent studies were excluded. Catheter based coronary angiography was the reference standard.

Forty-one studies (2515 patients) were analyzed. A random effects model was used to calculate summary estimates. The authors reported: “Analysis of all coronary segments yielded a sensitivity of 95% (80%, 89%, 86%, 98% for electron beam CT, 4/8-slice, 16-slice and 64-slice MDCT, respectively) for a specificity of 85% (77%, 84%, 95%, 91%).” They noted: “In conclusion, recent advances in CT technology have resulted in an increase in the proportion of coronary segments assessable by CT and in improved diagnostic accuracy from EBCT to 4/8, 16, and 64-slice MDCT. The latter improvement is best demonstrated by the all-segment analysis. With current 64 slice scanners, diagnostic accuracy of CE-CCT is high on a per segment basis. Per patient however, this accuracy may be lower in patients with multi-vessel disease, which may limit the clinical utility of CT in populations at high risk for CAD. The utility of CT in patients with intermediate risk for CAD remains to be established.”

Stein PD, Beemath A, Kayali F, et al. Multidetector computed tomography for the diagnosis of coronary artery disease: a systematic review. American Journal of Medicine 2006;119: 203-216.

In 2006, Stein and colleagues reported the results of a meta-analysis “to determine the sensitivity and specificity of contrast-enhanced multidetector computed tomography (CT) for the detection of coronary artery disease.” The authors included 33 studies (1606 patients), published from 2001 to 2005, that compared MSCT (4 to 16 slice and 1 study on 64 slice) with invasive coronary angiography. Studies were included if they reported type of machines, data on sensitivity and specificity and patient selection criteria. Abstracts, in vitro studies, series with < 10 patients were among those excluded. Meta-analysis model was not specified. Average sensitivity and specificity were calculated from pooled data. The authors reported: “Average sensitivity for patient-based detection of significant (>50% or >50%) stenosis was 61 of 64 (95%) with 4-slice CT, 276 of 292 (95%) with 16-slice CT, and 47 of 47 (100%) with 64-slice CT. Average specificity was 84% for 4-slice CT, 84% for 16-slice CT, and 100% for 64-slice CT.” They concluded: “Multidetector CT has the potential to be used as a screening test in appropriate patients. Contrast-enhanced 16-slice CT seems to be reasonably sensitive and specific for the detection of significant coronary artery disease but has shortcomings. Preliminary data with 64-slice CT suggest that it is more sensitive and specific.”

16 Slice MSCT

Garcia MJ, Lessick J, Hoffmann MHK, CATSCAN investigators. Accuracy of 16-Row Multidetector Computed Tomography for the Assessment of Coronary Artery Stenosis. JAMA 2006;296:403-411.

In 2006, Garcia and colleagues reported the results of a case series of 238 patients “to determine the diagnostic accuracy of 16-row MDCT for the detection of obstructive coronary disease.” Included patients were between 30 and 70 years of age who were referred for clinically indicated nonemergency coronary angiography, for evaluation of chest pain, and for intermediate or high probability of disease. Exclusion criteria included prior bypass surgery, arrhythmias, pacemakers/defibrillators, renal insufficiency and contrast allergy. MDCT was performed using 16 row scanners and was done prior to invasive angiography. Invasive angiography was the reference standard. Of the 238 patients, 187 underwent 16 row MDCT with contrast and β blocker drugs. Forty-five percent of patients were classified as intermediate probability for CAD and 55% as high probability, according to the ACC/AHA guidelines (Gibbons et al., 2002). Invasive angiography was the reference standard. Mean age was 60 years. Men comprised 68% of the study population. Of the 1629 segments, 29% were uninterpretable.

The authors reported: After censoring all nonevaluable segments as positive, the sensitivity for detecting more than 50% luminal stenoses was 89%; specificity, 65%; positive predictive value, 13%; and negative predictive value, 99%. In a patient-based analysis, the sensitivity for detecting patients with at least 1 positive segment was 98%; specificity, 54%; positive predictive value, 50%; and negative predictive value, 99%.”

The authors concluded: “The results of this study indicate that MDCT coronary angiography performed with 16-row scanners is limited by a high number of nonevaluable cases and a high false-positive rate. Thus, its routine implementation in clinical practice is not justified. Nevertheless, given its high sensitivity and negative predictive value, 16-row MDCT may be useful in excluding coronary disease in selected patients in whom a false-positive or inconclusive stress test result is suspected.” There was no follow-up on health outcomes.

Hoffmann MHK, Shi H, Schmitz BL, et al. Noninvasive coronary angiography with multislice computed tomography. JAMA 2005;293:2471-2478.

In 2005, Hoffmann and colleagues reported the results of a case series of 103 patients “to assess the accuracy and robustness of MSCT vs the criterion standard of invasive coronary angiography for detection of obstructive coronary artery disease.” All patients had suspected CAD, were in sinus rhythm, were able to hold their breath for 25 seconds, and had been referred for invasive coronary angiography prior to inclusion in the study. Exclusion criteria included prior revascularization, renal insufficiency and contrast allergy. Scans were performed using a 16 detector MSCT with contrast and β blocker drugs. Pretest probability for CAD was assessed according to ACC/AHA guidelines (Gibbons et al., 2002). Invasive coronary angiography was the reference standard. Mean age was 62 years. Men comprised 69% of the study population. For CAD, 2% were determined to have low probability; 63% at intermediate probability; and d 35% at high probability.

The authors reported: “Compared with invasive coronary angiography for detection of significant lesions (>50% stenosis), segment-based sensitivity, specificity, and positive and negative predictive values of MSCT were 95%, 98%, 87%, and 99%, respectively.” These estimates excluded 27% of the study patients who had “only partial coronary tree coverage available.” Of the 1384 segments, 88 (6.4%) were uninterpretable. Sensitivity, specificity, and positive and negative predictive values per patient were 97%, 87%, 90%, 95%, respectively. The authors concluded: “Multislice computed tomography provides high accuracy for noninvasive detection of suspected obstructive coronary artery disease. This promising technology has potential to complement diagnostic invasive coronary angiography in routine clinical care.” There was no follow-up on health outcomes.

Kuettner A, Beck T, Drosch T, et al. Diagnostic accuracy of noninvasive coronary imaging using 16-detector slice spiral computed tomography with 188 ms temporal resolution. J Am Coll Cardiol 2005;45:123–127.

In 2005, Kuettner and colleagues reported the results of a case series of 72 patients “to evaluate the diagnostic accuracy of 16-multi-detector spiral computed tomography (MDCT) with 188 ms temporal resolution.” All patients were scheduled for invasive angiography and also underwent MDCT imaging. Exclusion criteria include arrhythmias, renal insufficiency and contrast allergy. Scans were performed using 16 detector MDCT with contrast and β blocker drugs. Pretest probability was not specified. Invasive angiography was the reference standard. Mean age was 64 years. Men comprised 63% of the study population.

The authors reported: “Sensitivity, specificity, and positive and negative predictive values for the whole study group were as follows: 82%, 98%, 87%, and 97%, respectively. The correct clinical diagnosis of presence or absence of significant CAD was obtained in 65 of 72 (90%) patients.” Of the 936 segments, 62 (6.6%) were uninterpretable. Per patient estimates were not reported. The authors noted: “In conclusion, noninvasive MDCT imaging is becoming more and more accurate. However, further improvements of spatial and temporal resolution are still required to challenge diagnostic invasive coronary angiography.” There was no follow-up on health outcomes.

Mollet NR, Cademartiri1 F, Mieghem CV, et al. Adjunctive value of CT coronary angiography in the diagnostic work-up of patients with typical angina pectoris. European Heart Journal 2007;28:1872–1878.

In 2007, Mollet and colleagues reported the results of a consecutive series of 62 patients “to determine the adjunctive value of CT coronary angiography (CTCA) in the diagnostic work-up of patients with typical angina pectoris.” Patients included had typical angina, sinus heart rhythm and were able to hold their breaths for at least 20 seconds. Exclusion criteria included arrhythmias, renal insufficiency and contrast allergy. Scans were performed using 16 slice CT with contrast and β blocker drugs. Pre-test probability was high (81%). Invasive angiography was the reference standard. Mean age was 59 years. Men comprised 73% of the study population.

The authors reported sensitivity, specificity, PPV, NPV of 100%, 87%, 96%, 100%, respectively, per patient. They concluded: “Non-invasive CTCA is a potentially useful tool, in the diagnostic work-up of patients with typical angina pectoris, both to detect and to exclude significant CAD.” They also noted: “We have studied a relatively small number of patients who are at high risk of having significant CAD and excluded a significant number of patients because of logistic inability to perform CTCA before the conventional angiogram.” Health outcomes were not reported.

64 Slice MSCT

Meijboom WB, Mollet NR, Van Mieghem CA, et al. 64-slice computed tomography coronary angiography in patients with non-ST elevation acute coronary syndrome. Heart 2007 (online);doi:10.1136/hrt.2006.112771.

In 2007, Meijboom and colleagues reported the results of a non-consecutive case series of 104 patients to study “the diagnostic performance of 64-slice CT coronary angiography in patients with non-ST elevation acute coronary syndrome.” Patients presented with either unstable angina or non-ST elevation myocardial infarction. Exclusion criteria included atrial fibrillation, renal insufficiency and contrast allergy. Scans were performed using 64 slice CT with contrast and β blocker drugs. Pre-test probability was either high (68%) or low with positive or inconclusive exercise tests or high suspicion of CAD (32%). Invasive angiography was the reference standard. Mean age was about 59 years. Men comprised 72% of the study population.

The authors reported sensitivity, specificity, PPV, NPV of 100%, 75%%, 96%, 100%, respectively, per patient. Of the 1525 segments evaluated, 243 (15.9%) were not visualized and excluded. They concluded: “64-slice CT angiography has a high sensitivity to detect significant coronary stenoses and is reliable to exclude the presence of significant coronary artery disease in patients who present with a non-ST elevation acute coronary syndrome. The role of CT coronary angiography in these patients, particular in the lower risk group, needs to be further evaluated.” Health outcomes were not reported.

Francone M, Napoli A, Carbone I, et al. Noninvasive imaging of the coronary arteries using a 64-row multidetector CT scanner: initial clinical experience and radiation dose concerns. Radiol med 2007;112:31–46.

In 2007, Francone and colleagues reported the results of a case series of 114 patients to evaluate 64 detector CT. Of the 114 patients, 23 patients had MDCT to evaluate the coronary arteries for typical or atypical chest pain, 37 for evaluation of stent patency, 40 for patency of bypass grafts, 3 for inconclusive myocardial perfusion scintigraphy, and 11 for inconclusive stress echocardiography. Exclusion criteria included arrhythmia, kidney failure and contrast allergy. Scans were performed using 64 detector MDCT with contrast and β blocker drugs. Pretest probability was not reported. No reference standard was specified. Mean age was 63 years. Findings were not separately presented for the group of patients with chest pain. Test parameters and assessable segments were not reported.

The authors concluded: “In our initial clinical experience, the use of 64-MDCT has provided very promising results. Although the technique needs to be validated with systematic comparisons with clinical, laboratory and coronarographic data, the latest generation of 64-MDCT scanners offers new possibilities for clinical management of patients with coronary artery disease. The increase in spatial and temporal resolution translates into improved diagnostic image quality with respect to previous generations of multidetector devices. Thus, 64-MDCT is a noninvasive technique capable of identifying patients requiring interventional or surgical procedures such as selective coronarography with primary angioplasty or stent placement, or surgical revascularisation with bypass grafts. The use of suitable systems for the automatic control of radiation exposure seems nonetheless indispensable in order to limit patient dose, which given the current state of affairs is the main limitation to the clinical use of the technique.”

Ehara M, Surmely J, Kawai M, et al. Diagnostic accuracy of 64-slice computed tomography for detecting angiographically significant coronary artery stenosis in an unselected consecutive patient population. Circ J 2006;70:564–571.

In 2006, Ehara and colleagues reported the results of a case series of 69 patients “to investigate the accuracy of 64-slice MSCT (64 MSCT) in daily practice, without any patient selection.” Nineteen patients with suspected CAD, 50 patients with proven CAD were enrolled. Exclusion criteria included arrhythmias, renal insufficiency and contrast allergy. Scans were performed using a 64 slice MSCT machine with contrast and β blocker drugs as needed. Pretest probability was not specified. Reference standard was invasive angiography. Mean age was 67 years. Men comprised 75% of the study population.

The authors reported: “Compared with ICAG (invasive coronary angiography) the sensitivity of CTA to diagnose significant stenosis was 90%, specificity 94%, positive predictive value (PPV) 89% and negative predictive value (NPV) 95%. With regard to 58 stented lesions, the sensitivity, specificity, PPV and NPV were 93%, 96%, 87% and 98%, respectively. On the patient-based analysis, the sensitivity, specificity, PPV and NPV of CTA to detect CAD were 98%, 86%, 98% and 86%, respectively.” Of the 966 segments, 82 (8%) were uninterpretable. The authors concluded: “Sixty-four-MSCT has a high accuracy for the detection of significant CAD in an unselected patient population and therefore can be considered as a valuable noninvasive technique.” No health outcomes were reported.

Ropers D, Rixe J, Anders K, et al. Usefulness of multidetector row spiral computed tomography with 64- X 0.6-mm collimation and 330-ms rotation for the noninvasive detection of significant coronary artery stenoses. Am J Cardiol 2006;97:343–348.

In 2006, Ropers and colleagues reported the results of a case series of 84 patients to analyze “the accuracy of 64-slice MDCT coronary angiography for the detection of significant coronary artery stenoses compared with quantitative coronary angiography.” All patients enrolled in the study had been referred for invasive angiography due to suspected CAD. Exclusion criteria included acute coronary syndromes, arrhythmias, and contrast allergy. Scans were performed using 64 slice MDCT with contrast and β blocker drugs. Pretest probability was not specified. Invasive angiography was the reference standard. Mean age was 58 years. Men comprised 62% of the study population. The authors reported: “After exclusion of unevaluable coronary segments (4%), multidetector computed tomography demonstrated a sensitivity of 93%, a specificity of 97%, and a negative predictive value of 100% in a per-segment analysis. In a per-artery analysis, 15 of 336 arteries (4%) were unevaluable. Sensitivity and specificity in evaluable arteries were 95% and 93%, respectively. In a per-patient analysis (81 of 84 patients included), sensitivity and specificity were 96% and 91%, respectively.”

Other Nonspecified CTA

Budoff MJ, Gopal A, Gul KM, et al. Prevalence of obstructive coronary artery disease in an outpatient cardiac CT angiography environment. International Journal of Cardiology 2007; In Press.

In 2007, Budoff and colleagues reported the results of a descriptive study of 493 patients “to determine the prevalence of significant obstructive disease and non-diagnostic studies using coronary computed tomographic angiography (CTA) in an outpatient environment, to establish if CTA could help avoid unnecessary diagnostic cardiac catheterizations.” All patients that received CTA “over one year with an indication that could warrant a cardiac catheterization to establish the presence or absence of coronary artery disease (CAD).” Exclusion criteria included prior myocardial infarction, revascularization and congenital heart diseases. “Referred patients generally had an intermediate pre-test probability of obstructive disease (20–80%).” Specific pretest probabilities were not noted. Scans were performed using an electron beam scanner with unspecified detectors. Reference standard was not used for all patients. Mean age was 58 years. Men comprised 68% of the population. The authors reported: “Of the 493 index cases evaluated, 157 (32%) cases were reported to be normal, 204 patients were classified as having nonobstructive disease (41%), 93 patients were defined to have obstructive CAD (19%), and 39 cases were inconclusive (8%).” Sensitivity, specificity and predictive values were not reported. In this study, there was no comparison test. There was no follow-up on health outcomes and patients who received invasive angiography subsequently.

Dual Source CT

Heuschmid M, Burgstahler C, Reimann A, et al. Usefulness of noninvasive cardiac imaging using dual-source computed tomography in an unselected population with high prevalence of coronary artery disease. Am J Cardiol 2007;100:587–592.

In 2007, Heuschmid and colleagues reported the results of a case series of 51 patients “to evaluate the diagnostic accuracy of new DSCT in unselected patients with a high prevalence of CAD, irregular heart rate, and extensive calcific deposits.” All patients were scheduled for invasive angiography due to CAD. Exclusion criteria were unstable angina, renal insufficiency, allergy to contrast. Scans were performed using DSCT with contrast. Pretest probability was not specified. Invasive angiography was the reference standard. Mean age was 64 years. Men comprised 73% of the study population.

The authors reported: Based on a coronary segment model, sensitivity was 96%, specificity 87%, positive predictive value 61%, and negative predictive value 99% for the detection of significant lesions (>50% diameter stenosis).” Of the 632 segments that were not stented, 117 (18.5%) were uninterpretable. They concluded: “our initial data indicate that DSCT allows a high accuracy to exclude relevant coronary stenosis in unselected patients with a high prevalence of CAD and a relevant number with heart rhythm irregularities. However, overestimation of stenosis, especially in cases of calcifications, is still a limitation.” There was no follow-up on health outcomes.

Weustink AC, Meijboom WB, Moller NR, et al. Reliable high-speed coronary computed tomography in symptomatic patients. J Am Coll Cardiol 2007;50:786–794.

In 2007, Weustink and colleagues reported the results of a case series of 100 patients with chest pain “to prospectively evaluate the diagnostic performance of the high-speed dual-source computed tomography scanner (DSCT), with an increased temporal resolution (83 ms), for the detection of significant coronary lesions (>50% lumen diameter reduction) in a clinically wide range of patients.” All patients were symptomatic with “atypical angina, typical angina, and unstable coronary artery disease (unstable angina or non–ST segment elevation myocardial infarction) scheduled for conventional coronary angiography (CCA).” Patients with arrhythmias, past percutaneous coronary intervention, or bypass surgery, and allergy to contrast were excluded. Scans were performed using DSCT with contrast with nitroglycerin medication. Pretest probability was not specified. Invasive angiography was the reference standard. Mean age was 61 years. Men comprised 79% of the study population.

The authors reported: “Sensitivity, specificity, and positive and negative predictive values of DSCT coronary angiography for the detection of significant lesions on a segment-by-segment analysis were 95% (95% confidence interval [CI] 90 to 97), 95% (95% CI 93 to 96), 75% (95% CI 69 to 80), 99% (95% CI 98 to 99), respectively, and on a patient-based analysis 99% (95% CI 92 to 100), 87% (95% CI 65 to 97), 96% (95% CI 89 to 99), and 95% (95% CI 74 to 100), respectively.” Image quality was poor in 14% of the coronary segments. They concluded: “Dual source computed tomography scanner coronary angiography demonstrated a high diagnostic accuracy for the detection or exclusion of significant stenoses in patients with various heart rates without exclusion of unevaluable segments. These results indicate that the technique may now be tested in a cohort with a low-to-intermediate pretest probability of coronary artery disease or in patients with nonanginal chest pain to establish the role of DSCT coronary angiography in the management of patients with suspected coronary artery disease.”

Scheffel H, Alkadhi H, Plass A, et al. Accuracy of dual-source CT coronary angiography: first experience in a high pre-test probability population without heart rate control. Eur Radiol 2006;16:2739–2747.

In 2006, Scheffel and colleagues reported the results of a case series of 30 patients “to assess the diagnostic accuracy of dual source computed tomography (DSCT) for evaluation of coronary artery disease (CAD) in a population with extensive coronary calcifications without heart rate control.” Thirty patients who had invasive coronary angiography were included in the study. DSCT was performed within 30 days of catheterization. Exclusion criteria included previous stent or bypass surgery, renal insufficiency and contrast allergy. Scans were performed using DSCT with contrast and nitrate drugs. Based on a clinical score developed by Morise and colleagues (Morise et al., 1997), all patients were determined to have high pre-test probability of CAD. Invasive coronary angiography was the reference standard. Mean age was 63 years. Men comprised 80% of the study population.

The authors reported: “Overall sensitivity, specificity, positive and negative predictive value for evaluating CAD were 96.4, 97.5, 85.7, and 99.4%, respectively.” Of the 420 coronary segments, 6 (1.4%) were uninterpretable. They concluded: “First experience indicates that DSCT coronary angiography provides high diagnostic accuracy for assessment of CAD in a high pre-test probability population with extensive coronary calcifications and without heart rate control. Further studies are needed to confirm our results in appropriate clinical settings with larger patient populations.”

CTA of the coronary arteries in the ER Compared to Invasive Coronary Angiography

Goldstein JA, Gallagher MJ, O’Neil WW, et al. A randomized controlled trial of multi-slice coronary computed tomography for evaluation of acute chest pain. J Am Coll Cardiol 2007;49:863–871.

In 2007, Goldstein and colleagues reported the results of a randomized controlled trial “to compare the safety, diagnostic efficacy, and efficiency of multi-slice computed tomography (MSCT) with standard diagnostic evaluation of low-risk acute chest pain patients.” Inclusion criteria were chest pain or angina equivalent symptoms compatible with ischemia during the past 12 hours, age >25 years; and a prediction of a low risk of infarction and/or complications. Estimation of risk was done using a previously published clinical decision rule (Reilly et al., 2002). Exclusion criteria included known coronary artery disease, electrocardiograms diagnostic of cardiac ischemia and/or infarction, elevated serum biomarkers, contraindication to iodinated contrast and/or beta-blocking drugs, and atrial fibrillation or markedly irregular rhythm. Outcomes included safety, diagnostic efficacy, time and cost of care. Of the 197 patients, 99 were randomly assigned to receive MSCT (64 slice) with contrast and β blocker drugs and 98 to standard care (nuclear stress testing). Mean age was about 50 years. Men comprised about 50% of the study population. Almost all patients (196/197) were determined to be at very low risk using the Goldman Reilly criteria.

The authors reported no deaths, no myocardial infarctions, or other major adverse events in either group at 6 months. There was a significant difference in the proportion of patients discharged home from the ER (88% in the MSCT group versus 97% in the SOC group; p-value=0.03). The number of cardiac catheterizations at 6 months were not significantly different (12% in the MSCT group versus 7% in the SOC group; p-value=0.24). The MSCT scans were considered inadequate in 24.1% (24/99) of the patients and these patients then underwent nuclear stress testing. The authors concluded: “Multi-slice computed tomographic coronary angiography can definitively establish or exclude coronary disease as the cause of chest pain. However, inability to determine the physiological significance of intermediate severity coronary lesions and cases with inadequate image quality are present limitations.”

Olivetti L, Mazza G, Volpi D, et al. Multislice CT in emergency room management of patients with chest pain and medium-low probability of acute coronary syndrome. Radiol med 2006);111:1054–1063.

In 2006, Olivetti and colleagues reported the results of a case series of 31 patients “to evaluate the diagnostic accuracy of a 16-channel computed tomography (CT) scanner with dedicated software in a group of patients with chest pain and medium to low risk of ACS.” Inclusion criteria was “chest pain that was defined as medium to low probability of ACS” (absence of ischemic ECG ST changes and negative serum biomarkers). Exclusion criteria included previous revascularization, elevated heart rate, arrhythmias, various cardiac devices, and adverse reactions to contrast material. Scans were performed using 16 channel MDCT with contrast and β blocker drugs. Invasive angiography was the reference standard. Mean age was 59 years. Men comprised 61% of the study population. All patients received CT imaging and coronary angiography. The authors reported: “sensitivity of 65%, a specificity of 98.8%, a positive predictive value (PPV) of 81.2%, a negative predictive value (NPV) of 97.3% and an accuracy of 96.4%.” Of the 469 segments visualized, 383 (81.7%) were considered assessable. Image quality was considered “poor” in 19.8% of the segments (76/383). The authors concluded: “Due to its high NPV, this technique can rule out significant stenoses or coronary occlusions provided that image quality is excellent. In patients with a medium to low coronary risk, MSCT is a more accurate indicator of the need for coronary angiography than is exercise stress testing, which is less expensive but has lower predictive values.”

The New York Times, December 2, 2008, by Nicholas Bakalar — A cup of strong coffee might make you feel wide awake, but a small study suggests that for improved physical and mental performance, an afternoon nap works better.

Scientists spent a morning training 61 people in motor, perceptual and verbal tasks: tapping a keyboard in a specific sequence, discriminating between shapes on a computer screen and memorizing a list of words. Then the scientists randomly divided the subjects into three groups. The first took a nap from 1 to 3 p.m. At 3, the second group took a 200-milligram caffeine pill, and the third took a placebo. The subjects repeated the tasks they had been taught earlier and were scored by researchers who did not know which group they were in.

Those who had caffeine had worse motor skills than those who napped or had a placebo. In the perceptual task, the nappers did significantly better than either the caffeine or placebo group. On the verbal test, nappers were best by a wide margin, and the caffeine consumers did no better than those given a placebo. Despite their mediocre performance, caffeine takers consistently reported less sleepiness than the others.

“People think they’re smarter on caffeine,” said Sara C. Mednick, an assistant professor of psychiatry at the University of California, San Diego, and the lead author of the study, which appeared in the Nov. 3 issue of Behavioral Brain Research. “But this study is a strong argument for taking a nap instead of having a cup of coffee.”

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6SYP-4SFXK37-1&_user=10&_coverDate=11%2F03%2F2008&_rdoc=10&_fmt=high&_orig=browse&_srch=doc-info(%23toc%234840%232008%23998069998%23694970%23FLA%23display%23Volume)&_cdi=4840&_sort=d&_docanchor=&_ct=22&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=87f927affb72e0737a76f1857a1e014a

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The New York Times, December 2, 2008, by Michael W. Kahn MD — Recently, I asked a colleague about the quality of care her hospitalized mother was getting. “Well, you can at least have a conversation with her doctor,” she replied. Clearly this was a big relief.

High-level skills like reflectiveness and empathy are an important part of medical education these days. That is all to the good, of course. But as I noted last May in an article in The New England Journal of Medicine, medical schools may be underemphasizing a much simpler virtue: good manners.

In the article, I described a common-sense method for spreading clinical courtesy that I call “etiquette-based medicine,” and I proposed a simple six-step checklist for doctors to follow when meeting a hospitalized patient for the first time:

• Ask permission to enter the room; wait for an answer.

• Introduce yourself; show your ID badge.

• Shake hands.

• Sit down. Smile if appropriate.

• Explain your role on the health care team.

• Ask how the patient feels about being in the hospital.

Do doctors really need to be told to do such obvious things? Unfortunately, anyone who has spent time in the hospital as a patient or a physician knows how haphazardly such actions are performed, and as Samuel Johnson wrote, “Man needs more to be reminded than instructed.”

There is a useful analogy here to raising children. The British physician D. W. Winnicott coined the term “good enough mother” in part to help mothers who were overly anxious about their parenting skills. Rather than worry about trying to be perfect (whatever that meant), he urged them to relax, trust their intuition and realize that their children needed a mother who was caring, alert and reliable — in other words, good enough.

Similarly, when medical schools try to turn out ideal doctors, they can miss the opportunity to help them be good enough: perhaps not perfectly attuned to the patient, but at least respectful and professional. An etiquette-based approach can promote such behavior.

Etiquette-based medicine rests on the fact that patients derive comfort from specific actions — as opposed to attitudes or feelings — that are independent of the doctor’s emotional investment in the patient. My doctor may be tired, preoccupied or not that interested in me as a person; but I should still expect him or her to treat me with the kind of attentiveness and respect I recently received from a “genius” at the local Apple store.

The “genius” was skillful, efficient and professional, and solved my problem quickly without feeling my pain (which had been considerable). I don’t necessarily want or need to have an exceptional healer, but I would like to have good service. Patients should command at least the same regard from their doctors.

Does this mean surrendering medicine’s nobler values in the service of mere client satisfaction? Not at all. Consider one more analogy: A developing country may make a major investment in M.R.I. machines, an essential element of up-to-date medicine. But that money will be misspent if the country lacks enough antibiotics and doctors to prescribe them.

By the same token, trying to cultivate deeper human sensibility in doctors will be an inefficient use of scarce educational resources if those doctors cannot make the time to sit down, introduce themselves and make eye contact with their patients. Training good enough doctors should be like fluoridating the water supply or vaccinating children: uncomplicated, routine, relatively inexpensive — but with widespread and long-lasting benefits.

Michael W. Kahn is a psychiatrist in Boston.

The New York Times, December 2, 2008, by Tara Parker-Pope — A national panel of medical experts proposed significant and costly changes for training new doctors in the nation’s hospitals, recommending mandatory sleep breaks and more structured shift changes to reduce the risk of fatigue-related errors.

The report, issued by the Institute of Medicine, focused on the grueling training of medical residents, the recent medical school graduates who care for patients under the supervision of a fully-licensed physician. The medical residency, which aims to educate doctors by fully immersing them in a particular specialty and all aspects of patient care, is characterized by heavy patient workloads, 80-hour workweeks and sleep deprivation.

But while popular television shows like “Grey’s Anatomy” glamorize residency training as a gratifying rite-of-passage for doctors, the worry is that the massive workload imposed on residents poses a risk to patient safety. The long hours of often unsupervised residents were found to have contributed to the 1984 death of 18-year-old Libby Zion in New York, a finding that eventually led to a series of reforms, including limiting residents to an 80-hour workweek and 30-hour shifts.

But the expert panel said those reforms were not enough. Caps on work hours often aren’t enforced, and many residents still don’t get enough sleep, putting doctors and patients at risk for fatigue-related mistakes. While the new recommendations don’t reduce overall working hours for residents, the report says no resident should work longer than a 16-hour shift, which should be followed by a mandatory five-hour nap period.

The committee also called for better supervision of the doctors-in-training; prohibitions against moonlighting, or working extra jobs; mandatory days off each month; and assigning chores like wheeling patients to X-rays and drawing blood to other hospital workers so residents have more time for patient care.

“One of the problems has been that we limited the hours but didn’t change the work to make it better educationally and in terms of safety,” said panel member Dr. Kenneth M. Ludmerer, professor of medicine and history at Washington University in St. Louis. “You have to look at what they do during those hours. Is the total experience a learning experience?”

The panel paid particular attention to the so-called patient handoff, the point at which a resident briefs the next doctor about a patient’s history and needs as he or she is ending a work shift. The handoff is a risky time for patients, because rushed and fatigued doctors often inadequately brief incoming staff members, said Dr. Sandeep Jauhar, director of the heart failure program at Long Island Jewish Medical Center and a reviewer of the report.

Dr. Jauhar, who recently wrote about his medical training in the book “Intern: A Doctor’s Initiation,” recalls a time during his own residency when a fellow doctor-in-training rushed a patient briefing without giving him basic facts about the patient’s serious condition.

“When the nurse asked, ‘What do you want to do, doctor?’ I didn’t have a clue,” Dr. Jauhar said. “I didn’t have his case; I didn’t know what tests had been done. Each time you hand off a patient there is a possibility of error.”

But the big unanswered question from the Institute of Medicine report is whether medical schools and hospitals can afford the proposed changes, which may add as much as $1.7 billion in new costs to cover patient care during mandatory nap times and shift changes. The panel didn’t propose a funding source and said only that medical schools, hospitals, the Veterans Administration and other “stakeholders” in graduate medical training should meet to discuss the issue. Ultimately, whether the guidelines are enforced will be decided by the Accreditation Council for Graduate Medical Education, which is responsible for the accreditation of graduate medical training programs within the United States.

“We know there is a cost to this,” said Brian W. Lindberg, a panel member and executive director of the Consumer Coalition for Quality Health Care in Washington. “If we’re enabling residents to have sufficient sleep, someone has to cover care during those periods. We also believe if you look at the totality of the recommendations, there is the potential for efficiencies in the system and savings from reduction in errors and harms. In the long run, it won’t cost as much as one might estimate.”

While the need for reforms was generally applauded, some health care groups expressed frustration that more isn’t being done to relieve the workload of doctors-in-training.

“How is it reasonable for truckers in our country to be more restricted in their work hours than doctors and resident physicians,” asked Mary Carol Jennings, legislative director for the American Medical Student Association.

Dr. Peter Lurie, deputy director of Public Citizen’s Health Research Group said that the issue of doctor hours should be regulated by the government, and that the IOM report is unlikely to make a difference in patient care.

“It’s unlikely to be enforced,” said Dr. Lurie. “It gives the appearance of taking the problem seriously, but in fact, will likely maintain the status quo.”