Pharmacologic Control of Thromboembolic Complications of Cardiac-Valve Replacement

Continued experience with the use of dipyridamole as an antithrombotic agent confirmed earlier impressions of the clinical effectiveness of this agent. Dipyridamole (400 mg daily) or a placebo was given to 163 patients surviving prosthetic cardiac-valve replacement. All patients received anticoagulation with warfarin sodium. Eighty-four patients entered the placebo group. Within one year, 11.9 per cent died, 14.3 per cent suffered arterial emboli, and 9.5 per cent discontinued their medication because of possible side effects. The dipyridamole group contained 79 patients, of whom 13.9 per cent died; arterial emboli developed in 1.3 per cent and 15.2 per cent discontinued their medication. The frequency of embolization in the dipyridamole group was significantly lower than that in the placebo group. There was no significant difference between the death rates or between the drug discontinuation rates of the two groups.