Abstract WMP105: Risk-benefit Profile of Warfarin vs. Aspirin in Patients with Heart Failure and Sinus Rhythm: A Meta-Analysis
Objective: To comprehensively investigate the comparative risk-benefit profile of warfarin compared to aspirin in patients with heart failure who are in sinus rhythm.
Methods: Pubmed, EMBASE, Cochrane Central Register of Controlled Trials, and Clinicaltrials.gov from 1966 to June 2012 were systematically searched to identify relevant studies. The primary outcome was time to first stroke or death from any cause; secondary outcomes included any stroke, ischemic stroke, and major bleeding. We included randomized controlled trials that included a comparison of warfarin with aspirin, and in which the total number of patients and events were reported separately for active warfarin and aspirin groups. Relative risk (RR) with 95% confidence interval (CI) was used as a measure of the association between warfarin vs. aspirin therapy and risk of stroke or death, pooling data across trials using a random-effects model. Between-study heterogeneity was assessed using the I2 statistic.
Results: The search identified 4 randomized controlled trials of warfarin vs. aspirin therapy, enrolling 3663 patients, in which composite endpoint of stroke or death was reported as an outcome measure. Overall, there was no significant difference between the two treatments for the primary endpoint (warfarin vs. aspirin: RR 0.94, 95% CI 0.84 to 1.06, p=0.31) (Figure); and no heterogeneity across all trials (p=0.66, I2=0%). However, warfarin (vs. aspirin) was associated with lower risk of any stroke (RR 0.56, 95% CI 0.38 to 0.82, p=0.003) and ischemic stroke (RR 0.45, 95% CI 0.24 to 0.86, p=0.02) but a higher risk of major bleeding (RR 1.95, 95% CI 1.37 to 2.76, p=0.0002).
Conclusion: Among patients with heart failure who were in sinus rhythm, warfarin is no better than aspirin in preventing stroke or death from any cause. The observed stroke preventive benefit seen with warfarin appears to be offset by a significantly higher risk of major bleeding.
- © 2012 by American Heart Association, Inc.