Authors
Belch J, MacCuish A, Campbell I, et al.
Title
The prevention of progression of arterial disease and diabetes (POPADAD) trial: factorial randomised placebo controlled trial of aspirin and antioxidants in patients with diabetes and asymptomatic peripheral arterial disease.
References
BMJ 2008;337:1030-1044.
Background
Patients with diabetes and peripheral vascular disease are at higher risk for cardiovascular events. Antiplatelet therapy reduces CV events in patients with both diabetes and cardiovascular disease and in those with peripheral vascular disease.
Purpose
To determine whether aspirin and antioxidant therapy, combined or alone is more effective than placebo in reducing CV events in patients with diabetes and asymptomatic peripheral vascular disease.
Design
  • Multicenter, randomized, double-blind, placebo-controlled, 2x2 factorial design trials.
  • 1,276 patients, age ≥ 40 years with diabetes (type 1 or 2) and an ankle brachial index of ≤ 0.99, but no symptomatic cardiovascular disease.
Exclusion Criteria
None.
Follow-Up
6.7 years (mean)
Treatment Regimen
  • Aspirin 100 mg daily plus antioxidant capsule* or
  • Aspirin 100 mg daily plus placebo or
  • Placebo tablet vs antioxidant capsule *or
  • Placebo tablet plus placebo capsule

*antioxidant capsule : vitamin E 200 mg, ascorbic acid 100 mg, and trace elements
Results
Two composite primary endpoints:
  1. Death from coronary heart disease or stroke, nonfatal MI or stroke, or above ankle amputation for critical limb ischemia
  2. Death from coronary heart disease or stroke

No significant reduction in the first primary composite primary endpoint with either aspirin (18.2% for aspirin vs 18.3% for placebo) or antioxidant (18.3% for antioxidant vs 18.2% for placebo).

No significant reduction in the second primary composite endpoint with either aspirin (6.7% for aspirin vs 5.5% for placebo) or antioxidant (6.6% for antioxidant vs 5.7% for placebo).
Summary
Aspirin or antioxidants is not beneficial for primary prevention of cardiovascular events in patients with diabetes and asymptomatic peripheral vascular disease.
Implications
None.
Related Figures
[11]