Researchers challenge new guidelines on aspirin in primary prevention

The most recent guidelines for primary prevention recommend aspirin use for individuals ages 40 to 70 years who are at higher risk of a first cardiovascular event, but not for those over 70. Yet, people over 70 are at increasingly higher risks of cardiovascular events than those under 70. There has been considerable confusion from recently reported results of three large-scale randomized trials of aspirin in high risk primary prevention subjects, one of which showed a significant result, but the other two, based possibly on poor adherence and follow up, did not. As a result, health care providers are understandably confused about whether or not to prescribe aspirin for primary prevention of heart attacks or strokes, and if so, to whom.

In a commentary published online ahead of print in the American Journal of Medicine, researchers from Florida Atlantic University’s Schmidt College of Medicine and collaborators from the University of Wisconsin School of Medicine and Public Health, and the Harvard Medical School and Brigham and Women’s Hospital, provide guidance to health care providers and their patients. They urge that to do the most good for the most patients in primary care, health care providers should make individual clinical judgements about prescribing aspirin on a case-by-case basis.

“All patients suffering from an acute heart attack should receive 325 mg of regular aspirin promptly, and daily thereafter, to reduce their death rate as well as subsequent risks of heart attacks and strokes,” said Charles H. Hennekens, M.D., Dr.P.H., senior author, the first Sir Richard Doll Professor, and senior academic advisor in FAU’s Schmidt College of Medicine. “In addition, among long-term survivors of prior heart attacks or occlusive strokes, aspirin should be prescribed long-term unless there is a specific contraindication. In primary prevention, however, the balance of absolute benefits, which are lower than in secondary prevention patients, and risks of aspirin, which are the same as in secondary prevention, is far less clear.”

The researchers emphasize that, based on the current totality of evidence, any judgments about prescribing long-term aspirin therapy for apparently healthy individuals should be based on individual clinical judgments between the health care provider and each of his or her patients that weighs the absolute benefit on clotting against the absolute risk of bleeding.

The increasing burden of cardiovascular disease in developed and developing countries underscores the need for more widespread therapeutic lifestyle changes as well as the adjunctive use of drug therapies of proven net benefit in the primary prevention of heart attacks and strokes. The therapeutic lifestyle changes should include avoidance or cessation of smoking, weight loss and increased daily physical activity, and the drugs should include statins for lipid modification, and multiple classes of drugs likely to be necessary to achieve control of high blood pressure.

“When the magnitudes of the absolute benefits and risks are similar, patient preference assumes increasing importance,” said Hennekens. “This may include consideration of whether the prevention of a first heart attack or stroke is a more important consideration to a patient than their risk of a gastrointestinal bleed.”

Individual clinical judgements by health care providers about prescribing aspirin in primary prevention may affect a relatively large proportion of their patients. For example, primary prevention patients with metabolic syndrome, a constellation of overweight and obesity, hypertension, high cholesterol, and insulin resistance, a precursor to diabetes mellitus, affects about 40 percent of Americans over age 40. Their high risks of a first heart attack and stroke may approach those in survivors of a prior event.

“General guidelines for aspirin in primary prevention do not seem to be justified,” said Hennekens. “As is generally the case, the primary care provider has the most complete information about the benefits and risks for each of his or her patients.”

According to the United States Centers for Disease Control and Prevention, more than 859,000 Americans die of heart attacks or stroke every year, which account for more than 1 in 3 of all U.S. deaths. These common and serious diseases take a very large economic toll, costing $213.8 billion a year to the health care system and $137.4 billion in lost productivity from premature death alone.

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Collaborators in this commentary are Alexander Gitin, B.S., first author, an honors graduate of FAU and a first-year medical student at the University of Florida College of Medicine; David L. DeMets, Ph.D., the first Max Halperin Professor and chair emeritus of biostatistics and informatics at the University of Wisconsin School of Medicine and Public Health; and Marc A. Pfeffer, M.D., Ph.D., the first Dzau Professor of Medicine at Harvard Medical School.

Hennekens was the first to discover that aspirin prevents a first heart attack in men and stroke in women and has lifesaving benefits when given during a heart attack as well as among long-term survivors’ prior events. Science Watch ranked him as the third most widely cited medical researcher in the world from 1995 to 2005, and five of the top 20 were his former trainees and/or fellows. Science Heroes also ranked Hennekens No. 81 in the history of the world for having saved more than 1.1 million lives, and the Via Academy lists him as the No. 14 top living medical researcher in the world.

He has accepted an invitation to present these findings at the International Academy of Cardiology meeting in July in Boston.

About the Charles E. Schmidt College of Medicine:

FAU’s Charles E. Schmidt College of Medicine is one of approximately 152 accredited medical schools in the U.S. The college was launched in 2010, when the Florida Board of Governors made a landmark decision authorizing FAU to award the M.D. degree. After receiving approval from the Florida legislature and the governor, it became the 134th allopathic medical school in North America. With more than 70 full and part-time faculty and more than 1,300 affiliate faculty, the college matriculates 64 medical students each year and has been nationally recognized for its innovative curriculum. To further FAU’s commitment to increase much needed medical residency positions in Palm Beach County and to ensure that the region will continue to have an adequate and well-trained physician workforce, the FAU Charles E. Schmidt College of Medicine Consortium for Graduate Medical Education (GME) was formed in fall 2011 with five leading hospitals in Palm Beach County. The Consortium currently has five Accreditation Council for Graduate Medical Education (ACGME) accredited residencies including internal medicine, surgery, emergency medicine, psychiatry, and neurology.

About Florida Atlantic University:

Florida Atlantic University, established in 1961, officially opened its doors in 1964 as the fifth public university in Florida. Today, the University, with an annual economic impact of $6.3 billion, serves more than 30,000 undergraduate and graduate students at sites throughout its six-county service region in southeast Florida. FAU’s world-class teaching and research faculty serves students through 10 colleges: the Dorothy F. Schmidt College of Arts and Letters, the College of Business, the College for Design and Social Inquiry, the College of Education, the College of Engineering and Computer Science, the Graduate College, the Harriet L. Wilkes Honors College, the Charles E. Schmidt College of Medicine, the Christine E. Lynn College of Nursing and the Charles E. Schmidt College of Science. FAU is ranked as a High Research Activity institution by the Carnegie Foundation for the Advancement of Teaching. The University is placing special focus on the rapid development of three signature themes – marine and coastal issues, biotechnology and contemporary societal challenges – which provide opportunities for faculty and students to build upon FAU’s existing strengths in research and scholarship. For more information, visit http://www.fau.edu.