The effect of Warfarin (W) was compared with a combination of Warfarin and Dipyridamole (W+D) on the incidence of arterial thrombo-embolism in patients with prosthetic heart valves in a prospective randomised study. Sixty-four and 53 patients were allocated to W and W+D. The two groups were comparable as regards age, sex, arrhythmias and site and type of valves. The dose of W was determined by regular monitoring of prothrombin ratio 0.9 - 3) and that of D by monitoring serum D levels to between 2 and 4 μmol/l. The mean period of follow-up was 26.98 months (range 1 to 36) for W and 22.02 months (range 1 to 36) for W+D. Six patients in W and 1 in W+D developed arterial thrombo-embolic episodes giving an incidence of 0.0035 per patient month for W and 0.0009 per patient month for W+D. An actuarial analysis of the yearly incidence of thrombo-embolism confirmed the superiority of W+D over W. Of the 6 failures in W, 5 were in sinus rhythm and 1 in atrial fibrillation and all had cerebral embolic episodes. The failure in W+D was a patient in atrial fibrillation who died suddenly 6 weeks after surgery and the post-mortem showed clots on both mitral and aortic prostheses.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.