Antithrombotics in heart failure: background to the WARCEF study

Three controlled clinical studies in the early 1950s reported that warfarin reduced death and

thromboembolism in patients with heart failure. Uncontrolled studies have suggested a reduction

of stroke by warfarin in "cardiomyopathy" and many clinicians use warfarin for this purpose. The

stroke rate in heart failure is low (about 2% per year) and this makes clinically useful risk

reduction difficult and a prospective study costly. As for atrial fibrillation, there may be subgroups

of heart failure patients with high-stroke risk who could benefit from warfarin and these need to

be defined. Cognitive impairment is increasingly recognized as a complication of heart failure, and

its risk factors need to be characterized. WARCEF (Warfarin vs. Aspirin in Reduced Cardiac

Ejection Fraction) study reduces its sample size by combining death and stroke as the primary

endpoint and by including patients with prior stroke.