SPAF IIStroke Prevention in Atrial Fibrillation II study |
| Authors: |
(a) Stroke Prevention in Atrial Fibrillation investigators
(b) Ezekowitz MD, James KE |
| Titles: |
(a) Warfarin versus aspirin for prevention of thromboembolism in atrial fibrillation: Stroke Prevention in Atrial Fibrillation II study
(b) Stroke Prevention in Atrial Fibrillation II study (letter) |
| References: |
(a) Lancet 1994;343:687-91
(b) Lancet 1994;343:1508-9 |
| Disease: |
Atrial fibrillation |
| Purpose: |
To assess the differential effects of warfarin and aspirin in preventing ischaemic stroke in patients with atrial fibrillation in two age- groups |
| Study Design: |
Randomised, open, parallel-group |
| Follow-up: |
Mean 2.3 years |
| Patients: |
1100 patients, 715 aged = 75 years and 385 aged > 75 years |
| Treatmentregimen: |
Warfarin, to give an international normalised ratio 2.0-4.5, or aspirin, 325 mg/day |
| Results: |
In the younger patients warfarin decreased the absolute rate of primary events by 0.7% per year compared to aspirin. The primary event rate per year was 1.3% with warfarin and 1.9% with aspirin (p = 0.24). Among older patients warfarin decreased the absolute rate of primary events by 1.2% per year compared to aspirin. The primary event rate per year was 3.6% with warfarin and 4.8% with aspirin (p = 0.39). In this older group the rate of all stroke with residual deficit (ischaemic or haemorrhagic) was 4.3% per year with aspirin and 4.6% per year with warfarin. In younger patients rates of major haemorrhage were 0.9% per year with aspirin and 1.7% per year with warfarin (p = 0.17). For older patients, the data were, respectively, 1.6% and 4.2% (p = 0.04). In older patients assigned to warfarin, the annual rate of intracranial haemorrhage was significantly higher than in younger patients (p = 0.05) |
