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

Abstract

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.

Aspirin dose and six-month outcome after an acute coronary syndrome

“…However, the majority of the data used in this analysis was drawn from trials of low-dose aspirin in cerebrovascular or peripheral vascular disease. Here aspirin doses as low as 30 to 50 mg daily (5,8) have been extensively studied and provide equivalent protection from death, non-fatal stroke, or MI as higher doses. Kong et al (27), using random effects models, have re-examined the Antithrombotic Trialist's data.…”

“…The evidence to support the equivalent efficacy of aspirin doses between 75 and 325 mg is mainly drawn from indirect comparisons between trials of different aspirin dose and direct comparisons in patients with cerebrovascular (5-7) or peripheral vascular (8) disease. There have been only two small direct comparisons of low and intermediate aspirin doses in patients with ACS, only one of which has been published (9).…”

Antithrombotic Therapy After Peripheral Angioplasty

“…The doses tested ranged from 50 mg / day to 1000 mg / day. The three studies showed that higher doses of aspirin had no advantage on early reocclusion (within one month) and were more likely to cause gastrointestinal side effects including peptic ulcer (Weichert et al, 1994;Minar et al, 1995;Ranke et al, 1994).…”

Collaborative meta-analysis of randomised trials of antiplatelet therapy for prevention of death, myocardial infarction, and stroke in high risk patients

“…31 †Includes two trials comparing 75-325 mg aspirin daily v <75 mg aspirin daily 32 33 and one trial of 500-1500 mg aspirin daily v <75 mg aspirin daily. 34 ‡Includes cilostazol, sulotroban, trapidil, E5510, eptifibatide, and GR32191B. Stratified ratio of odds of an event in regimen 1 group to that in regimen 2 group is plotted for each group of trials (black square) along with its 99% confidence interval (horizontal line).…”