Controlled trial of high- versus low-dose aspirin treatment after percutaneous transluminal angioplasty in patients with peripheral vascular disease.

Percutaneous transluminal angioplasty of aortoiliac and femoropopliteal atherosclerotic lesions can provide long-lasting hemodynamic improvement. High-dose aspirin is commonly prescribed as reocclusion prophylaxis, but low doses would be preferable because of fewer adverse effects. We performed a double-blind, randomized, controlled clinical trial in patients with peripheral vascular disease with lesions appropriate for angioplasty. We compared the efficacy and side effects of two doses of aspirin (50 mg vs. 900 mg daily) during a period of 12 months after angioplasty. A total of 359 patients were evaluated: 175 were randomly assigned to treatment with 900 mg aspirin daily and 184 to 50 mg aspirin daily. Thirty-nine patients developed restenosis at the angioplasty site; the cumulative percentage of event-free survival after 1 year (patency rate) was 85% in 900 mg group and 84% in 50 mg group. An equivalence test showed the two groups equivalent with respect to restenosis rates (P = 0.0003 for an equivalence region of < 10% difference. Nine patients (5%) in the 900 mg group had serious gastrointestinal side effects (peptic ulcer, 8; erosive gastritis requiring transfusion, 1) compared to two ( peptic ulcer) in the 50 mg group (P = 0.03). The results of our study show that a dose of 50 mg aspirin a day is as effective as 900 mg for the prevention of restenoses after lower limb angioplasty, and that severe gastrointestinal side effects are less frequent.