SPAFStroke Prevention in Atrial Fibrillation |
| Authors: |
(a) and (b) Stroke Prevention in Atrial Fibrillation study group investigators |
| Titles: |
(a) Preliminary report of the Stroke Prevention in Atrial Fibrillation Study
(b) Stroke prevention in atrial fibrillation study. Final results |
| References: |
(a) N Engl J Med 1990;322:863-8
(b) Circulation 1991;84:527-39 |
| Disease: |
Nonrheumatic atrial fibrillation |
| Purpose: |
To investigate the safety and efficacy of warfarin and aspirin (as separate treatments) for the primary prevention of ischaemic stroke and systemic thromboembolism in patients with atrial fibrillation unrelated to rheumatic valvular disease |
| Study Design: |
Randomised, open (warfarin), double-blind (aspirin-placebo), placebo-controlled, parallel-group |
| Follow-up: |
Mean 1.3 years |
| Patients: |
1330 patients with atrial fibrillation. The group eligible to receive warfarin (group 1) comprised 627 patients (210 warfarin, 206 aspirin and 211 placebo) and the group not eligible to receive warfarin (group 2) comprised 703 patients (346 aspirin and 357 placebo) |
| Treatmentregimen: |
Warfarin adjusted to prolong prothrombin time to achieve an international normalised ratio between 2.0 and 3.5, and/or aspirin, 325 mg/day |
| Results: |
In group 1, the rate of systemic stroke and systemic embolism was substantially reduced in those assigned to warfarin (2.3%/ year) compared to placebo (7.4%/year) (p = 0.01; risk reduction 67%). The risk of death or a primary event was reduced by 58% in those receiving warfarin (p = 0.01). There was also a 54% reduction in disabling ischaemic stroke or vascular death in those receiving warfarin compared to placebo. In all patients receiving aspirin (groups 1 and 2 combined), there were fewer primary events (3.6%/year; p = 0.02; risk reduction 42%) and an overall reduction in primary events or death of 32% (p = 0.02). The risk reduction for ischaemic strokes, transient ischaemic attacks and systemic emboli in this double-blinded portion of the study was 44% (p < 0.01). Disabling ischaemic stroke or vascular death was reduced by 22% (p = 0.33) in patients receiving aspirin compared to placebo |
