A recent meta-analysis of 10 randomized trials, including nearly 6000 patients with acute coronary syndrome who did not undergo stenting, concluded that adding warfarin to aspirin therapy reduced the incidence of myocardial infarction (MI), stroke, and revascularization procedures. The researchers stratified patients into low-, medium-, and high-risk categories for purposes of estimating cardiovascular and bleeding risks. For MI, addition of warfarin was associated with a 44% risk reduction. Overall risk reduction relative to stroke in the meta-analysis was 54%. Mean risk reduction for revascularization procedures (coronary artery bypass graft or percutaneous transluminal coronary angioplasty) was 20%. The combination of aspirin and warfarin resulted in higher rates of major bleeding, the majority of which were in high-risk patients. Mortality rates were similar for the aspirin-only and combination therapy groups. The investigators concluded that, for patients at high cardiovascular risk with a low risk of bleeding (eg, a 60-yearold man with diabetes and congestive heart failure), the benefits of adding warfarin to aspirin therapy far outweigh the risks associated with the combination.
Dr. Garrett is a clinical pharmacist practitioner at Cornerstone Health Care in High Point, NC.