A Platelet-Inhibitor-Drug Trial in Coronary-Artery Bypass Operations

TLDR

The study tested whether dipyridamole given two days before and aspirin added seven hours after surgery could prevent occlusion of aortocoronary-artery-bypass grafts in 407 patients. Vein-graft angiography was performed in 360 patients (88 %) within six months of operation, with a median of eight days. The combination of dipyridamole and aspirin reduced early graft occlusion from 10 % to 3 % (and from 21 % to 8 % for any occlusion), a benefit that persisted across subgroups and did not increase postoperative bleeding. Published in N Engl J Med 1982;307:73–8.

Abstract

To prevent occlusion of aortocoronary-artery-bypass grafts, we conducted a prospective, randomized-double-blind trial comparing dipyridamole (instituted two days before operation) plus aspirin (added seven hours after operation) with placebo in 407 patients. Vein-graft angiography was performed in 360 patients (88 per cent) within six months of operation (median, eight days). Within one month of operation, 3 per cent of vein-graft distal anastomoses (10 of 351) were occluded in the treated patients, and 10 per cent (38 of 362) in the placebo group; the proportion of patients with one or more distal anastomoses occluded was 8 per cent (10 of 130) in the treated group and 21 per cent (27 of 130) in the placebo group. This benefit in graft patency persisted in each of over 50 sub-groups. Early postoperative bleeding was similar in the two groups. In this trial dipyridamole and aspirin were effective in preventing graft occlusion early after operation. (N Engl J Med. 1982;307:73–8.)