Intra-cardiac thrombosis (4 trials: acenocoumarin plus aspirin (65 patients) versus acenocoumarin alone (57 patients);
warfarin plus 500 mg aspirin (75 patients) versus warfarin alone (73 patients);
warfarin plus 250 mg aspirin (170 patients) versus warfarin plus 100 mgdipyridamole (181 patients) versus warfarin alone (183 patients); and
warfarin plus slow-release aspirin (186 patients) versus warfarin plus placebo (184 patients).
Unstable angina or non-Q myocardial infarction (1 trial): 162.5 mg aspirin plus warfarin (105 patients) versus 162.5 mg aspirin alone (109 patients).
High-risk men (1 trial): warfarin plus 75 mg aspiring (911 patients) versus warfarin plus placebo (917 patients) versus 75 mg aspirin plus placebo (907 patients) versus double placebo (932 patients).
Combined therapies. High-intensity oral anticoagulation plus high-dose aspirin: 609 person-years; 7.2 major bleedings per 100 person-years (95% confidence interval, CI: 5.1, 9.3, p=0.06).
High-dose aspirin, high-intensity oral anticoagulation plus low-dose aspirin: 282 person-years; 8.5 major bleedings per 100 person-years (95% CI: 6.0, 11.0, p=0.02).
Low-intensity oral anticoagulation plus low-dose aspirin: 1,022 person-years; 5 major bleedings per 100 person-years (95% CI: 3.7, 6.3, p>0.05).
Reference therapies. High-intensity oral anticoagulation: 1,222 person-years; 3.3 major bleedings per 100 person-years (95% CI: 2.3, 4.3, p=0.62).
Low-intensity oral anticoagulation: 1,020 person-years; 3.6 major bleedings per 100 person-years (95% CI: 2.5, 4.7, p=0.28).
Low-dose aspirin: 1,070 person-years; 2.2 major bleedings per 100 person-years (95% CI: 1.3, 3.1, p=0.62).
Placebo: 1,057 person-years; 2.5 major bleedings per 100 person-years (95% CI: 1.5, 3.5, p=0.62).