Stroke in patients with heart failure and reduced left ventricular ejection fraction

Background: Cardiac failure is associated with both stroke of presumed card ioembolic origin and a high mortality rate. Warfarin is used frequently in patients with reduced cardiac left ventricular ejection fraction (EF), alth ough no randomized trials have confirmed that anticoagulation benefits thes e patients. Methods: A literature review was performed pertaining to the fr equency of stroke and mortality, and the effect of antithrombotic agents on stroke and mortality rates, in patients with cardiac failure or reduced ca rdiac EF, We also reviewed the main features of two new proposed studies (W arfarin and Antiplatelet Therapy in Chronic Heart Failure [WATCH] and Warfa rin Versus Aspirin in Reduced Cardiac Ejection Fraction [WARCEF]) comparing warfarin and antiplatelet agents in patients with low EF. Results: The ris k of stroke increases with decreasing EF and the risk of mortality increase s with the clinical severity of cardiac failure (New York Heart Association class). Data from heart failure treatment studies suggest that warfarin ma y reduce stroke and mortality in patients with reduced EF, but definitive a nswers are lacking. The stroke rate alone is too low to be used as a primar y endpoint, but an endpoint combining stroke and death (as WARCEF and WATCH propose) should allow an assessment of the effect of antithrombotics in ca rdiac failure, Amalgamating the data on stroke from these two trials should yield enough statistical power to compare the effects of warfarin and aspi rin on stroke as an independent secondary endpoint. Conclusion: Whether war farin is superior to aspirin in reducing stroke and mortality in patients w ith low ejection fraction is an important clinical issue that warrants pros pective evaluation.