A new study offers “no compelling reason” to use warfarin instead of aspirin in heart failure patients who don’t have atrial fibrillation. In a paper published in the New England Journal of Medicine, Shunichi Homma and members of the Warfarin versus Aspirin in Reduced Cardiac Ejection Fraction (WARCEF) study group report the results of a trial in which 2,305 patients with left ventricular dysfunction were randomized to warfarin or placebo and followed for up to six years.
No significant differences were observed in the primary endpoint (the composite of death, ischemic stroke, or intracerebral hemorrhage) or its individual components. Warfarin was superior to aspirin in reducing the rate of ischemic stroke, but this advantage was offset by an increased incidence of major hemorrhage in the warfarin group.
- Primary endpoint: 26.4% for warfarin versus 27.5% for aspirin, HR 0.93, CI 0.79-1.10
- Ischemic stroke: 1.8% versus 3.5%, HR 0.55, CI 0.32-0.96)
- Major hemorrhage: 5.8% versus 2.7%, OR2.21, CI 1.42-3.47
The authors concluded:
Given the finding that warfarin did not provide an overall benefit and was associated with an increased risk of bleeding, there is no compelling reason to use warfarin rather than aspirin in patients with a reduced LVEF who are in sinus rhythm.
In an accompanying editorial, John Eikelboom and Stuart Connolly agree with the study authors that there is no justification for the “routine clinical use of warfarin in most patients with heart failure” but write that warfarin is still “most likely to benefit” heart failure patients with atrial fibrillation or with a history of cardioembolic stroke or formation of LV thrombus. They leave open the possibility that warfarin may also benefit heart failure patients with underlying coronary artery disease, and recommend that future studies of anticoagulants in heart failure focus on this population.