Effects of low-dose aspirin on restenosis after coronary angioplasty.

After angioplasty of a previously untreated native coronary artery and after 2 weeks of aspirin therapy, 216 subjects (aged less than 70 years without acute infarction) were randomized to treatment with soluble aspirin, 100 mg/day, or placebo to study the effect on restenosis. Follow-up, defined as angiography at 6 months, earlier angiographic restenosis or coronary bypass surgery was completed by 108 aspirin- and 104 placebo-treated patients. Restenosis (stenosis greater than or equal to 50% plus loss of greater than or equal to 50% of gain, or surgery) occurred in 38 (35%) aspirin- and 45 (43%) placebo-treated subjects (p = not significant). No patient died. Restenosis occurred in 42 of 168 (25%) aspirin- and 51 of 135 (38%) placebo-treated lesions (p less than 0.025). Aspirin-treated lesions (n = 163) had lost 16 +/- 22% (mean +/- standard deviation) of lumen and placebo-treated lesions 22 +/- 25% of lumen (n = 134) at angiography (p less than 0.01). There were more left anterior descending lesions in the placebo group and these had a higher recurrence rate than other lesions. The beneficial effect of aspirin was not dependent on this, although significance was reduced in subgroup analysis. Loss of lumen in left anterior descending lesions was 20 +/- 24% (n = 57) in the aspirin-treated and 27 +/- 25% (n = 70) in the placebo-treated lesions (p less than 0.1). It is concluded that there is a small beneficial effect of low-dose aspirin on restenosis after coronary angioplasty.(ABSTRACT TRUNCATED AT 250 WORDS)