Aspirin and the Primary Prevention of Cardiovascular Disease

The aspirin a day regimen that many Americans are on to prevent a cardiovascular event is now being questioned with new research.  Dr. Irv Loh, a cardiology contributor for our Cardiology HUB contributed an article on the subject.

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Over the last several decades, it has been accepted that clinical evidence validates the use of aspirin in the secondary prevention of cardiovascular after acute coronary syndromes, percutaneous or surgical coronary interventions, peripheral or neurovascular diseases. Many of us, including myself, would often recommend aspirin for primary prevention in patients we felt were high risk, but who had not yet sustained a clinical event.

Bayer Pharmaceuticals has been petitioning the FDA for such a primary prevention indication for many years and after a rigorous review of the extant well-designed clinical trial data, the FDA recently rendered its opinion (1).

The FDA announced that aspirin should not be allowed to market itself for the primary prevention of myocardial infarction or cerebrovascular accidents in individuals without prior history of cardiovascular disease, even in patients at ostensibly high risk, including diabetics. An important concern was that the risk of gastrointestinal or cerebrovascular bleeding exceeded the very small signal suggesting benefit. This is at variance (so far) with the American Heart Association/American College of Cardiology (2) as well as the U.S. Preventive Services Task Force (3) which have acknowledged the role of aspirin for primary prevention.

As many of you know, this discussion was thrust forward with the 1989 publication of the Physicians’ Health Study (4). Nine subsequent primary prevention trials of the role of aspirin ensued and were rigorously reviewed by the FDA (5,6). Although none showed compelling evidence of benefit, a meta-analysis (7) did suggest a small benefit in reduction of nonfatal MIs, though not sufficient enough to over-ride the known increased risks of GI and CNS bleeds.

With these data and recommendations, we will need to recalibrate our aspirin message and pay attention to those patients who may now wish to stop aspirin, since our colleagues at the Mayo Clinic have made us aware of a small risk of rebound effect (8). We simply need to make sure that our patients engage us before any significant changes are made.

In the interim, we will continue to monitor on-going clinical trials and adjust our thinking accordingly. Let’s close with a brief review of who should be receiving aspirin therapy for cardiovascular diseases:

Strokes: Aspirin use recommended in both men and women to treat transient ischemic attack or ischemic stroke to prevent subsequent cardiovascular events or death.

Myocardial infarctions: reduces the risk of death in patients with suspected acute MI and reduces recurrent MI and reduces the risk of MI or sudden death in patients with unstable and chronic stable angina.

Other atherothrombotic conditions: Secondary prevention in patients who have had procedures such as angioplasty, stents and coronary bypass operations.

Bio: Irv Loh MD FACC FAHA FCCP FACP

Dr. Loh is a board certified internist and subspecialty board certified cardiac specialist with an emphasis on preventive cardiology. He founded and directs the Ventura Heart Institute, which conducts education, research and preventive cardiovascular programs. Dr. Loh is a former Assistant Professor of Medicine at UCLA School of Medicine.

References

1. Use of Aspirin for Primary Prevention of Heart Attack and Stroke http://www.fda.gov/drugs/resourcesforyou/consumers/ucm390574.htm

2. Aspirin and heart disease. American Heart Association. http://www.heart.org/HEARTORG/Conditions/HeartAttack/PreventionTreatmentofHeartAttack/Aspirin-and-Heart-Disease_UCM_321714_Article.jsp

3. Aspirin for the prevention of cardiovascular disease. U.S. Preventive Services Task Force. http://www.uspreventiveservicestaskforce.org/uspstf/uspsasmi.htm

4. Aspirin in the prevention of coronary disease http://www.ncbi.nlm.nih.gov/pubmed/2594041

5. Hennekens CH. Benefits and risks of aspirin in secondary and primary prevention of cardiovascular disease. http://www.uptodate.com/home/index

6. Pignone M, et al. Aspirin for primary prevention of cardiovascular events in people with diabetes. Journal of the American College of Cardiology. 2010;55:2878

7. Seshasia SRK, et al. Effect of aspirin on vascular and nonvascular outcomes: Meta-analysis of randomized controlled trials. Archives of Internal Medicine. 2012;172:209.

8. http://www.mayoclinic.org/diseases-conditions/heart-disease/in-depth/daily-aspirin-therapy/art-20046797