Warfarin and Aspirin after Heart-Valve Replacement

To the Editor: In a recent paper (Aug. 19 issue), Turpie et al. report a beneficial effect of adding aspirin to warfarin treatment for heart-valve recipients 1 . We question the interpretation of this study. The risk of major embolism among patients who received both aspirin and warfarin was 1.6 percent per year, a figure higher than those from the literature for treatment with oral anticoagulants only. Bloomfield et al. 2 found a 12-year cumulative risk of 8.8 percent, which corresponds to an annual incidence of about 0.8 percent (and not, as stated by Turpie et al., of 2 to 3 percent, . . .