Authors
Fowkes FG, Price JF, Stewart MC, et al.
Title
Aspirin for Prevention of Cardiovascular Events in a General Population Screened for a Low Ankle Brachial Index.
References
JAMA 2010;303:841-848.
Background
A low ankle brachial index (ABI) is used to diagnose peripheral vascular disease, signifying atherosclerosis. It is associated with an increased risk of future cardiovascular events. Antiplatelet therapy is useful for the secondary prevention of events in patients with known vascular disease, however the degree of benefit is unknown in asymptomatic individuals with low ABI.
Purpose
To determine whether individuals with a low ABI would derive benefit from aspirin therapy for preventing ischemic events.
Design
  • Randomized, double-blind trial in Scotland
  • 3,350 individuals, aged 50-75 years with ABI ≤ 0.95
Exclusion Criteria
None.
Follow-Up
8.2 years (mean)
Treatment Regimen
Aspirin 100 mg/day vs Placebo
Results
Primary endpoint: Composite of fatal or nonfatal coronary event or stroke or revascularization.

There was no significant difference in the primary endpoint (13.7 events per 1000 person-years with aspirin vs 13.3 with placebo). There was no significant difference in vascular events or all-cause mortality. There was an increase in the risk of major bleeding requiring hospital admission (2.5 per 1000 person-years with aspirin vs 1.5 with placebo).

The trial was stopped 14 months early due to the low chance of finding a difference in the primary endpoint and an increase in major bleeding in the aspirin group (p<0.05).

Summary
Aspirin does not decrease vascular events in patients with asymptomatic low ABI and no known cardiovascular disease.
Implications
None.
Related Figures
[8]