CONSENSUS AND GUIDELINES · July 22, 2014

TAKE-HOME MESSAGE

• This review discusses the advantages and drawbacks of using aspirin in primary cardiovascular prevention.The authors favor the use of low-dose aspirin as a prevention treatment in patients at high cardiovascular risk and who do not have increased risk for bleeding.

Expert Comment Primary Care
Peter Lin MD, CCFP

ASA for secondary prevention is a clear choice because patients have already demonstrated that they do create clots because they have already had their stroke or MI. However, for primary prevention, it is a more difficult decision because the patients comprise a heterogeneous population and have not yet joined the stroke or MI club. Some of them will be at very high risk for CV disease and some very low; some of them may have very high bleeding risk and some very low bleeding risk. Yet, all of them would be in the primary prevention group because they have not had an event yet. This variability is what makes it difficult to say that all people should be using ASA as primary prevention.

In order to make the choice easier, these authors state that we should assess the CV disease risk and the bleeding risk before we decide on the use of ASA. If the patient has high bleeding risks that are not correctable, then we should not use ASA because we will do more harm than good. If the bleeding risk is not high then we should look at the CV risk: if it is greater than 20% over the next 10 years then treat with ASA. If the patient is at less than a 10% risk, no treatment is needed because the potential benefits are very low. If your patient is in the middle, 10% to 20% risk for CV disease, treatment should be decided on a case-by-case basis.

As always, we should try to eliminate the risk factors for bleeding (eg, over-the-counter NSAIDS, herbals that might affect coagulation, alcohol, etc). Eliminating these things can reduce the risk for bleeding on ASA.

What about patients already on ASA for primary prevention right now? We have many studies that say starting ASA for primary prevention might not be useful, but there no studies saying that stopping ASA is okay. Hence, the key is to inform patients of their risk for CV disease and bleeding and then decide—along with the individual patient—whether to continue or not. But, remember a stroke is not the same as a GI bleed; many patients would prefer a GI bleed to a stroke.

It’s not just a simple numbers game. So, for each patient, let us ask two questions: 1) is the CV risk high enough? 2) can we minimize the bleeding risk? The bottom line is to “do no harm.” Let’s be real doctors and assess the risks and benefits of ASA for each of our patients.

ABSTRACT

Although the use of oral anticoagulants (vitamin K antagonists) has been abandoned in primary cardiovascular prevention due to lack of a favorable benefit-to-risk ratio, the indications for aspirin use in this setting continue to be a source of major debate, with major international guidelines providing conflicting recommendations. Here, we review the evidence in favor and against aspirin therapy in primary prevention based on the evidence accumulated so far, including recent data linking aspirin with cancer protection. While awaiting the results of several ongoing studies, we argue for a pragmatic approach to using low-dose aspirin in primary cardiovascular prevention and suggest its use in patients at high cardiovascular risk, defined as ≥2 major cardiovascular events (death, myocardial infarction, or stroke) projected per 100 person-years, who are not at increased risk of bleeding.

Journal of the American College of Cardiology
Aspirin Therapy in Primary Cardiovascular Disease Prevention: A Position Paper of the European Society of Cardiology Working Group on Thrombosis

J Am Coll Cardiol 2014 Jul 22;64(3)319-327, S Halvorsen, F Andreotti, JM Ten Berg, M Cattaneo, S Coccheri, R Marchioli, J Morais, FW Verheugt, R De Caterina
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.