Warfarin and Aspirin in Patients with Heart Failure and Sinus Rhythm New England Journal of Medicine, 05/04/2012

Homma S et al. – Among patients with reduced left ventricular ejection fraction (LVEF) who were in sinus rhythm, there was no significant overall difference in the primary outcome between treatment with warfarin and treatment with aspirin. A reduced risk of ischemic stroke with warfarin was offset by an increased risk of major hemorrhage. The choice between warfarin and aspirin should be individualized.

• The authors designed this trial to determine whether warfarin (with a target international normalized ratio of 2.0 to 3.5) or aspirin (at a dose of 325 mg per day) is a better treatment for patients in sinus rhythm who have a reduced left ventricular ejection fraction (LVEF).
• The authors followed 2305 patients for up to 6 years (mean [±SD], 3.5±1.8).
• The primary outcome was the time to the first event in a composite end point of ischemic stroke, intracerebral hemorrhage, or death from any cause.

• The rates of the primary outcome were 7.47 events per 100 patient–years in the warfarin group and 7.93 in the aspirin group (hazard ratio with warfarin, 0.93; 95% confidence interval [CI], 0.79 to 1.10; P=0.40).
• There was no significant overall difference between the two treatments.
• In a time–varying analysis, the hazard ratio changed over time, slightly favoring warfarin over aspirin by the fourth year of follow–up, but this finding was only marginally significant (P=0.046).
• Warfarin, as compared with aspirin, was associated with a significant reduction in the rate of ischemic stroke throughout the follow–up period (0.72 events per 100 patient–years vs. 1.36 per 100 patient–years; hazard ratio, 0.52; 95% CI, 0.33 to 0.82; P=0.005).
• The rate of major hemorrhage was 1.78 events per 100 patient–years in the warfarin group as compared with 0.87 in the aspirin group (P<0.001).
• The rates of intracerebral and intracranial hemorrhage did not differ significantly between the two treatment groups (0.27 events per 100 patient–years with warfarin and 0.22 with aspirin, P=0.82).