Low-dose acetylsalicylic acid (100 mg/day) after aortocoronary bypass surgery: a placebo-controlled trial.

The effect of low-dose acetylsalicylic acid (100 mg/day) upon bypass patency-rate and clinical course after aortocoronary bypass surgery was investigated in a randomized, placebo-controlled clinical trial. Sixty patients with 143 distal anastomoses of bypasses were randomized, 46 underwent repeat angiography after 4 months. Using the intention to treat-strategy, treatment was superior to placebo as judged by bypass patency rate and occurrence of cardiovascular complications or death. Counting the six drop-outs as failures, only nine of the 31 patients of the placebo group, but 16 of the 29 patients of the treatment group were considered successes (P less than 0.04). Eighteen patients in the placebo group and eight patients of the treatment group received beta-adrenoceptor blockers postoperatively, suggesting again a favourable effect of the treatment. Adverse drug reactions were very rare and minor. Supported by pathophysiological insights and positive trends in similar trials, the positive result justifies the recommendation of prescribing 100 mg of acetylsalicylic acid once daily to all patients without contraindications after aortocoronary bypass surgery. The positive result of this trial warrants further clinical trials of low-dose acetylsalicylic acid for other indications in arterial diseases.