British Doctors Trial - British Doctors Trial
Aspirin vs placebo for primary prevention
To determine if prophylactic daily aspirin would reduce the incidence of major cardiovascular events.
Patients Screened: ~20,000
Patients Enrolled: 5139
NYHA Class: Not reported
Mean Follow Up: 6 year
Mean Patient Age: <60: 47%, 60-69: 39%, 70-79: 14%
Mean Ejection Fraction: Not evaluated
Male physicians <80 years old who were listed in UK Medical Directory
Aspirin use or contraindications to its use History of peptic, ulcer, stroke, or MI
Fatal or nonfatal MI
Total mortality, nonfatal MI or stroke
Randomized in 2:1 fashion to aspirin 500 mg/day (or 300 mg/day enteric formulation) or no therapy (instructed to avoid aspirin). By 1 year, 19% allocated to aspirin stopped taking it, and during the next 5 years an additional 5% discontinued therapy. In the group allocated to avoid aspirin, ~2%/year began to use it, usually because vascular disease had developed.
There were no significant differences in the rates of fatal or nonfatal MI between the two groups (10.2/1000 pt years [aspirin] vs 9.7/1000 pt years). Daily aspirin was associated with a significant reduction in the frequency of confirmed transient cerebral attacks (1.6/1000 pt years vs 2.8/1000 pt years, p<0.05). However, the aspirin group had a small, nonsignificant excess of fatal and nonfatal strokes (4.8/1000 pt years vs 4.1/1000 pt years). Strokes defined as "probably hemorrhagic" also occurred at similar rates (0.16/1000 pt yrs [aspirin] vs 0.21/1000 pt years [controls]). All-cause and vascular mortality rates were 10% and 6%lower, respectively, in the aspirin group than in the control group (3.6% vs 4.2%, 4.3% vs 4.6%) but these differences were not statistically significant.
The use of aspirin for primary prevention was not associated with a significant reduction in major cardiovascular events. In particular, there was no reduction in nonfatal MI associated with aspirin use, a finding seen in the larger US Physicians Health Study (see N Engl J Med 1989;321:129–135).
BMJ 1988; 296: 313-6.
Clinical Topics: Prevention
Keywords: Coronary Artery Disease, Stroke, Platelet Aggregation Inhibitors, Vascular Diseases, Primary Prevention
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