U.S. Department of Health and Human Services
NATIONAL INSTITUTES OF HEALTH NIH News
National Institute on Drug Abuse (NIDA) <http://www.nida.nih.gov/>
For Immediate Release: Monday, March 15, 2010
New Study Sheds Light on a Neurochemical Vulnerability that Could Contribute to Psychopathic Behaviors
Normal individuals who scored high on a measure of impulsive/antisocial traits display a hypersensitive brain reward system, according to a brain imaging study by researchers at Vanderbilt University. The findings provide the first evidence of differences in the brain’s reward system that may underlie vulnerability to what’s typically referred to as psychopathy.
The study in the current issue of the journal Nature Neuroscience was funded by the National Institute on Drug Abuse (NIDA), a component of the National Institutes of Health.
Psychopathy is a personality disorder characterized by a combination of superficial charm, manipulative and antisocial behavior, sensation-seeking and impulsivity, blunted empathy and punishment sensitivity, and shallow emotional experiences. Psychopathy is a particularly robust predictor of criminal behavior and recidivism.
Since psychopathic individuals are at increased risk for developing substance use problems, the Vanderbilt team decided to investigate possible links between the brain’s reward system (activated by abused substances and natural reward), and a behavioral trait (impulsive/antisociality) characteristic of psychopathy. Researchers used two different technologies to measure the brain’s reward response.
In the first experiment, positron emission tomography (PET) was used to image the brain’s dopamine response in subjects who received a low oral dose of amphetamine. Dopamine is a brain chemical associated with reward and motivation.
In the second experiment, the same subjects participated in a game, in which they could make (or lose) money while their brains were being scanned using functional magnetic resonance imaging (fMRI).
The results in both cases show that individuals who scored high on a personality assessment that teases out traits like egocentricity, manipulating others, and risk taking had a hypersensitive dopamine response system. The picture that emerges from these high resolution PET and fMRI scans suggests that alterations in the function of the brain’s reward system may contribute to a latent psychopathic trait.
The researchers speculate that a heightened response to an anticipated reward could make such individuals less fearful about the consequences of their behavior, which, combined with a reduced sensitivity to others’ emotions and resistance to learning from mistakes, could lead to the manipulative and aggressive style of behaviors that is common in psychopaths.
The traits analyzed in this study have been previously shown to predict antisocial behavior and substance abuse in both incarcerated and community samples.
“By linking traits that suggest impulsivity and the potential for antisocial behavior to an overreactive dopamine system, this study helps explain why aggression may be as rewarding for some people as drugs are for others,” said NIDA Director Dr. Nora Volkow. “However, while having an antisocial trait may be a driving factor, it is clearly not sufficient to trigger aggressive behaviors; thus, we need to continue to investigate the other contributors to psychopathy.”
While the Vanderbilt researchers believe they’ve made an important first step showing that characterizations of psychopathic behavior are closely related to changes in brain activity, they hope to validate their findings with new studies on individuals who have been actually diagnosed as psychopaths.
“The amount of dopamine released was up to four times higher in people with high levels of these traits, compared to those who scored lower on the personality profile,” says Joshua Buckholtz, doctoral candidate in neuroscience and the lead author of the study.
“Because of these exaggerated dopamine responses, individuals with a latent psychopathic trait may become focused on a chance to get a reward, and less able to shift their attention until they get what they’re after. This pattern, along with other traits, could develop into psychopathic personality disorder.”
The National Institute on Drug Abuse is a component of the National Institutes of Health, U.S. Department of Health and Human Services. NIDA supports most of the world’s research on the health aspects of drug abuse and addiction. The Institute carries out a large variety of programs to inform policy and improve practice. Fact sheets on the health effects of drugs of abuse and information on NIDA research and other activities can be found on the NIDA home page at <www.drugabuse.gov. To order publications in English or Spanish, call NIDA’s new DrugPubs research dissemination center at 1-877-NIDA-NIH or 240-645-0228 (TDD) or fax or email requests to 240-645-0227 or <e-mail:firstname.lastname@example.org>. Online ordering is available at <http://drugpubs.drugabuse.gov>. NIDA’s new media guide can be found at <http://drugabuse.gov/mediaguide>.
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Safety and Effectiveness Trial Evaluated the Arctic Front® Cardiac CryoAblation Catheter System for the Treatment of Paroxysmal Atrial Fibrillation
- Cryoablation is an alternative that is growing in popularity. Over the past decade, more patients have been referred for ablation procedures when drugs proved ineffective.
- Atrial fibrillation is the most common heart disorder, affecting 2.2 million Americans and 10 million people worldwide. It significantly raises the risk of stroke.
- Anti-arrhythmic drugs eliminate the condition in about half of all patients but can have adverse side effects.
- Less than 1 percent of patients treated with cryoablation were hospitalized for a recurrence of the disease, compared with 6 percent in the drug group.
MINNEAPOLIS and ATLANTA – March 15, 2010 – A noninvasive procedure that freezes and kills problem-causing heart tissue was nearly 10 times better at eliminating a potentially serious heart rhythm disorder than conventional anti-arrhythmic drugs, researchers said on Monday.
A clinical trial of Medtronic Inc’s cryoablation system looked at 245 patients with paroxysmal atrial fibrillation, a condition marked by intermittent episodes of abnormal heart rhythm that causes the upper chambers of the heart to quiver.
A small pilot study funded by St. Jude Medical Inc (STJ.N) compared the two therapies in a sicker population of patients and also found that the procedure worked better than drugs.
Atrial fibrillation is the most common heart disorder, affecting 2.2 million Americans and 10 million people worldwide. It significantly raises the risk of stroke.
Patients in the Medtronic-sponsored trial who underwent the cryoablation procedure — which involves using a catheter to freeze away the heart tissue where the problem originates — was just as safe as drugs used to treat the condition and far more effective, meeting the study’s primary goal of eliminating atrial fibrillation one year after the procedure.
Dubbed Stop-af, the Medtronic trial showed that almost 70 percent of patients who had cryoablation remained free of the condition after one year, compared with just 7 percent of patients who received drug therapy, according to data presented at the American College of Cardiology meeting in Atlanta.
“This is the best data we have at this point in support of cryoablation (to treat atrial fibrillation),” said Dr. Douglas Packer of Mayo Clinic, the lead investigator of the study.
Medtronic, Inc.announced data from the STOP AF (Sustained Treatment of Paroxysmal Atrial Fibrillation) clinical trial during late-breaking sessions at the 59th Annual Scientific Session of the American College of Cardiology in Atlanta. The data showed superiority over anti-arrhythmic drugs, with 69.9 percent of patients with paroxysmal atrial fibrillation (PAF) treated with the Arctic Front® Cardiac CryoAblation Catheter System remaining free of atrial fibrillation (AF) one year after cryoablation, compared to 7.3 percent on drug therapy. All primary safety and effectiveness endpoints in the trial were met. The Arctic Front® Cardiac CryoAblation Catheter System is commercially available for use in Europe and certain other countries outside the United States and is under investigational use in the United States.
“These data are a promising indication of the safety profile of cryoablation and its effectiveness in isolating the pulmonary veins to stop AF,” said Kevin Wheelan, M.D., chief of staff at Baylor Heart and Vascular in Dallas and investigator with the STOP AF trial. “The cryoballoon demonstrated strong results in treating PAF patients who had previously failed drug treatment.”
About STOP AF
As presented at ACC.10 by Douglas Packer, M.D., professor of Medicine, Mayo Clinic in Rochester, Minn. and principal investigator, the STOP AF pivotal clinical trial studied the safety and effectiveness of the Medtronic Arctic Front Cardiac CryoAblation Catheter System in paroxysmal AF patients as compared to drug therapy. Patients were randomized to receive either cryoablation or anti-arrhythmic drug therapy. For every three patients enrolled, approximately two received an ablation and one was randomly assigned to the drug therapy group. Twenty-six U.S. and Canadian centers enrolled 245 patients (163 cryoablation and 82 anti-arrhythmic drugs). Outcomes on all patients were assessed through 12-months of follow-up. These results are part of the PMA submission in consideration for U.S. Food and Drug Administration (FDA) approval for the Medtronic Arctic Front Cardiac CryoAblation Catheter System.
The primary effectiveness outcome was treatment success and was defined as having both acute procedural success and freedom from chronic treatment failure for those patients randomized to cryoablation. Acute procedural success was defined as demonstration of electrical isolation in three or more pulmonary veins at the conclusion of the first cryoablation procedure. Using this definition, acute procedural success was achieved in 98.2 percent (160/163) of cryoablation patients. Chronic treatment failure was defined as the occurrence of detectable AF after a 90-day blanking period (the time after treatment when an AF event is not counted). Chronic treatment failure also included the occurrence of an AF intervention or the use of a non-protocol AF drug anytime during the 12-month follow up. At 12 months, 69.9 percent of cryoablation patients demonstrated treatment success compared to 7.3 percent of anti-arrhythmic drug patients.
The two primary safety outcome measures were Cryoablation Procedure Events (CPEs) in cryoablation subjects and Major Atrial Fibrillation Events (MAFEs) in both study groups. The data indicate that both primary safety outcomes were met. Cryoablation patients with one or more CPE(s) was 3.1 percent with a one-sided 95 percent upper confidence bound of 6.3 percent, which was significantly less than the 14.8 percent pre-specified upper confidence bound (p < 0.001). No treatment-related deaths or atrioesophageal fistulas (bleeding between the esophagus and atrium) were reported. In addition, 96.9 percent of cryoablation patients were free from MAFE(s), compared to 91.5 percent of anti-arrhythmic drug patients (p < 0.001, non-inferiority).
The trial also captured safety data on several of the more common complications of any ablation procedure in 228 patients that underwent cryoablation procedures including those randomized to cryoablation (163) and those who crossed over for cryoablation (65) after failing drug therapy. Phrenic nerve palsy, a recognized observation with this technology, was noted after 11.2 percent of all cryoablation procedures (29/259) in 228 patients. At 12 months, 224 of the 228 patients (98.2 percent) that received a cryoablation were free of any effects related to phrenic nerve injury. In other safety findings, seven patients (3.1 percent) developed pulmonary vein (PV) stenosis; only two required treatment. Across clinical trials there is considerable variation in the definition and calculation of pulmonary vein stenosis. In STOP AF, PV stenosis was defined as a reduction in the calculated pulmonary vein cross-sectional area to less than 25 percent of the baseline pulmonary vein cross-sectional area. A vein that was stenotic at anytime during study follow-up was considered stenotic for this analysis.
About the Medtronic Arctic Front Cardiac CryoAblation Catheter System
The Medtronic Arctic Front Cardiac CryoAblation Catheter System is designed to be used with fluoroscopy and does not require the use of complex, three-dimensional electroanatomical mapping systems. The technologies used in the STOP AF trial include:
- The Arctic Front Cryocatheter, which inflates and fills with coolant to ablate the tissue where the pulmonary veins enter the left atrium;
- The FlexCath® Steerable Sheath, which helps deliver and position the cryocatheter in the left atrium;
- The Freezor® MAX Cardiac CryoAblation Catheter, which is a single-point catheter used to provide additional ablations, as needed; and
- The CryoConsole, which houses the coolant, electrical and mechanical components that run the catheters during a cryoablation procedure.
A catheter ablation is a minimally invasive procedure that aims to stop the rapid beating of the upper heart chambers by ablating, or blocking, the conduction of AF, including where the pulmonary veins enter the left atrium. The Arctic Front Cardiac CryoAblation Catheter System uses cryoablation, or freezing technology. A coolant is released into the catheter’s balloon to freeze and ablate the tissue; freezing helps the balloon maintain contact with the tissue. To date, more than 9,000 patients have been treated worldwide with the Arctic Front cryocatheter.
Caution: The Medtronic Arctic Front Cardiac CryoAblation Catheter System is investigational and not currently available for sale in the United States. The device is limited by federal law to investigational use only.
About Atrial Fibrillation
Atrial fibrillation is an irregular quivering or rapid heart rhythm in the upper chambers (atria) of the heart. Paroxysmal AF occurs when the irregular rhythm starts and stops suddenly on its own. Half of all diagnosed AF patients fail drug therapy.¹ Untreated AF patients have a five times higher risk of stroke.² Atrial fibrillation causes inefficient pumping of the heart and can lead to other rhythm problems as well as chronic fatigue, difficulty breathing and heart failure. AF is the most common heart arrhythmia affecting more than 3 million Americans and 7 million people worldwide.³
Medtronic, Inc. (www.medtronic.com), headquartered in Minneapolis, is the global leader in medical technology – alleviating pain, restoring health, and extending life for millions of people around the world.
Any forward-looking statements are subject to risks and uncertainties such as those described in Medtronic’s periodic reports on file with the Securities and Exchange Commission. Actual results may differ materially from anticipated results.
¹ JAMA 2001; 285:2370-5.
² Fuster et al. Journal of the American College of Cardiology. 2006; 48:854-906.
³ Millennium Research Report; “Global Markets For Atrial Fibrillation Treatment Devices 2008,” March 2008; 1.
FierceHealthCare.com, by Dan Bowman, March 15, 2010 — Some primary-care doctors apparently are beginning to feel like “second-class citizens” compared to certified nurse anesthetists (CRNAs), who in 2009 were offered average salaries of $189,000 by medical centers, compared with $173,000 for the doctors. And physician recruiting and consulting firm Merritt Hawkins & Associates, who compiled those numbers, believes that such a divide will only be closed minimally for 2010, which could add to the growing shortage of primary-care physicians, reports CNNMoney.com.
Merritt Hawkins & Associates staffing expert Kurt Mosley said that 2009 was the fourth consecutive year that CRNAs were offered more money than primary-care docs. The firm expects CRNAs to receive average salary offers of $186,000 for this year, compared with $178,000 for primary care-doctors.
Mosley pointed to a high rate of surgeries as one of the catalysts behind the increase for CRNAs, but warned that such a trend will only discourage medical students from pursuing primary care.
“The demand for primary-care doctors will increase twofold when health reform happens and millions of more Americans have access to healthcare,” Mosley said. “Who is going to triage these patients? It’s not the neurologist or the pulmonologist. It has to be the primary-care doctor.”
The American Association of Nurse Anesthetists, on the other hand, sees nothing wrong with such projections, and stated that such payment for CRNAs is fair.
“Once nurses and physicians arrive at anesthesia training, we use the same textbooks and same cases,” said Lisa Thiemann, senior director of professional services with the AANA. “The training is not too different between the two groups. We all deliver anesthesia the same way.”
FierceHealthCare.com, by Caralyn Davis, March 15, 2010 — By 2020, New Jersey faces a projected shortfall of more than 2,800 physicians (approximately 1,000 primary care physicians and 1,800 specialists) beyond the current supply in the physician graduate medical education production pipeline, according to a report from the Physician Workforce Policy Task Force established by the Trenton-based New Jersey Council of Teaching Hospitals and several partner organizations.
While this projection is worrying, it could actually be worse. The best-case scenario is a dearth of only 2,500 physicians, but in a worst-case scenario, the shortfall could top 3,100 physicians.
The projected shortage represents “a 12 percent gap in the physician supply vs. the likely population demand for services,” says the Task Force. “There is a current shortage within primary-care specialties, including family medicine, geriatrics, general surgery, and obstetrics. Within non-primary care specialties, neurosurgery and pediatric sub-specialties are the most alarming. Over 70 percent of all pediatric sub-specialties have serious shortages.” (Note: The Task Force’s demand predictions are based on the implementation of health reform.)
State government should work with New Jersey medical schools and teaching hospitals to create a centralized strategic planning alliance to drive policy, regulations, funding and recruitment/retention programs to manage the physician supply, recommends the Task Force.
Published on FierceHealthcare (http://www.fiercehealthcare.com)
wsj.com, by Laura Landro, March 15, 2010 — As the shortage of primary-care physicians mounts, the nursing profession is offering a possible solution: the “doctor nurse.”
More than 200 nursing schools have established or plan to launch doctorate of nursing practice programs to equip graduates with skills the schools say are equivalent to primary-care physicians. The two-year programs, including a one-year residency, create a “hybrid practitioner” with more skills, knowledge and training than a nurse practitioner with a master’s degree, says Mary Mundinger, dean of New York’s Columbia University School of Nursing. She says DNPs are being trained to have more focus than doctors on coordinating care among many specialists and health-care settings.
Dawn Bucher, DNP, and child patient at Ivanhoe Clinic in Ivanhoe, Minn.
To establish a national standard for doctors of nursing practice, the non-profit Council for the Advancement of Comprehensive Care plans to announce Wednesday that the National Board of Medical Examiners has agreed to develop a voluntary DNP certification exam based on the same test physicians take to qualify for a medical license. The board will begin administering the exam this fall. By 2015, the American Association of Colleges of Nursing aims to make the doctoral degree the standard for all new advanced practice nurses, including nurse practitioners.
But some physician groups warn that blurring the line between doctors and nurses will confuse patients and jeopardize care. Nurses with doctorates use DrNP after their name, and can also use the designation Dr. as a title. Physician groups want DNPs to be required to clearly state to patients and prospective students that they are not medical doctors. “Nurses with an advanced degree are not the same as doctors who have been to medical school,” says Roger Moore, incoming president of the American Society of Anesthesiologists.
“With four years of medical school and three years of residency training, physicians’ understanding of complex medical issues and clinical expertise is unequaled,” adds James King, president of the American Academy of Family Physicians. While nurses with advanced degrees play an important role in delivering care, Dr. King says they should work as part of a physician-directed team.
Although there are no precise statistics on the number of nurses with doctorates because the programs are relatively new, there are about 1,874 DNP students currently enrolled in programs nationwide, up from 862 students in 2006, according to the American Association of Colleges of Nursing.
Nurses have increasingly been moving into more specialized and advanced roles over the past few decades. Advanced-practice nurses include specialists in fields such as nurse midwives and nurse anesthetists, and there are now more than 125,000 nurse practitioners in the U.S. Nurse practitioners in some states are required to work with or be supervised by physicians, but often have independent practices in family medicine, adult care, pediatrics and oncology.
A study led by Columbia’s Dr. Mundinger and published in the Journal of the American Medical Association in 2000 showed comparable patient outcomes in patients randomly assigned to nurse practitioners and primary-care physicians.
Nurse practitioners fear the doctoral programs might be raising the bar too high for their profession. The American Academy of Nurse Practitioners says it supports access to a higher educational degree for nurses, but wants to ensure that members won’t be marginalized or required to go back to school for a costly advanced degree. Nurse practitioners can write prescriptions, are eligible for Medicare and Medicaid reimbursement, and often act as the primary health-care provider for their patients.
“Nurse practitioners with master’s degrees are already filling the primary-care shortages and providing quality, cost-effective care, many times in places that physicians are unwilling to practice,” says Wendy Vogel, a nurse practitioner specializing in oncology at Blue Ridge Medical Specialists in Bristol, Tenn. There are “as yet no data to support the need for increasing the amount of education required to practice in this role,” she says.
With an acute shortage of nurses, some medical professionals worry that the doctoral programs, with promises of higher-paying jobs and prestige, will lure more nurses away from the critical tasks of day-to-day bedside care.
But program proponents say they could help bring more nurses into the profession by increasing the number of faculty candidates to train a new generation of nurses. The U.S. Bureau of Labor Statistics says that more than one million new and replacement nurses will be needed by 2016. Still, nursing schools had to turn away 40,285 qualified applicants to bachelor’s and graduate nursing programs in 2007 in part because of an insufficient number of faculty, according to the American Association of Colleges of Nursing.
Dr. Mundinger, of Columbia, says the primary aim of the DNP is not to usurp the role of the physician, but to deal with the fact that there simply won’t be enough of them to care for patients with increasingly complex care needs. As doctors face shrinking insurance reimbursements and rising malpractice-insurance costs, more medical students are forsaking primary care for specialty practices with higher incomes and more predictable hours. As a result, there could be a shortfall ranging from 85,000 to 200,000 primary-care physicians by 2020, according to various estimates.
In addition to training in diagnostic and treatment skills, doctors of nursing practice can have hospital admitting privileges, coordinate care among specialists, help patients with preventive care, evaluate their social and family situations, and manage complex illnesses such as diabetes and heart disease, says Dr. Mundinger, who has been leading the effort behind the National Board of Medical Examiners’ planned certification exam.
A spokeswoman for the medical licensing board, which provides examinations used by licensing authorities for several health professions, says the planned DNP exam will be narrower in scope than the three-step exam that doctors take, including tests on organ systems and a range of medical disciplines. A number of physicians have supported the efforts to advance nursing to the doctorate level through the Council for the Advancement of Comprehensive Care.
All nurses currently are licensed by the state in which they practice and are certified by specialty groups. The planned certification exam won’t be a requirement for licensing of DNPs, and it is too early to say whether it will catch on broadly as a desirable credential for practice. Jeanette Lancaster, president of the American Association of Colleges of Nursing says “we are keeping an open mind as to whether it will add another level of validation of competency.”
Columbia University’s Columbia Advanced Practice Nurse Associates, which includes several DNPs, has for several years been taking care of patients with complex illnesses, working with medical doctors and specialists affiliated with the university. Judith Gleason, a 76-year-old writer and researcher, says she became a patient of the practice after her family physician died. Now, she counts one of Columbia’s DNPs as her primary physician.
Ms. Gleason says she liked the practice’s emphasis on preventive care. More significantly, when she complained of a throbbing headache on one side of her head, Edwidge Thomas, a doctor of nursing practice, noticed something in her blood test that indicated a form of rheumatic infection linked to her arthritis. The diagnosis was confirmed when Ms. Gleason was referred to a neurologist, who prescribed medication. “They are patient-oriented, and they always pick up the pieces, so to speak,” says Ms. Gleason. “Edwidge is my primary-care provider now.”
FierceHealthCare.com, March 15, 2010 — A study appearing in the journal Health Affairs attaches some numbers to a problem we all see coming–the growing U.S. shortage of primary care physicians. According to the study, by 2025 the U.S. will see a shortage of 35,000 to 44,000 family or general internal medicine physicians who care for adults. Worse, with population growth and an aging population figured in, existing family physicians and general internists will see their workloads grow by a substantial 29 percent by 2025 (versus 2005 levels) if nothing is done.
RealAge.com, March15, 2010, by Mehmet C. Oz, MD, and Michael F. Roizen, MD — Struggling to feel at home in the gym? You don’t have to go. Seriously, working out at home can be just as effective when it comes to losing weight and lowering your risk of type 2 diabetes.
How do we know? Two groups of people did resistance-training workouts for the better part of a year. Researchers gave some people at-the-gym programs; others were given simple low-tech exercises they could do using household objects (like soup cans), elastic bands for resistance, and their own body weight (think push-ups). By the end of the study, the scientists saw that a gym membership didn’t guarantee success: People in both groups lost about the same amount of weight. And the number of people with abnormally high blood sugar (called impaired glucose tolerance) dropped significantly in both groups.
Our point is: It doesn’t matter where you work out. If you prefer the music, the equipment, or even the eye candy at the gym, fine. If you would rather do your thing in the privacy of your home, perfect. What really matters is that you choose a workout routine you will do, and not just once. We YOU Docs use our homes and the gym for our workouts — whatever is easiest.
At home, you can keep it simple with a few dumbbells, some resistance bands, and a mat. You don’t even have to get the dumbbells (although, like knives and power tools, the right equipment for the right job does make everything easier). Start with soup cans or filled grocery bags (reusable ones!) for biceps curls and other upper-body exercises.