BRISTOL, UNITED KINGDOM. The past ten years have seen an intensive turf war between proponents of warfarin therapy (anticoagulation) and aspirin therapy (antiplatelet treatment) in the prevention of stroke in patients with non- rheumatic atrial fibrillation. The push for widespread use of warfarin (Coumadin) came after a trial that found a 68 per cent lower incidence of ischemic stroke in a group of atrial fibrillation patients who were receiving warfarin as compared to a group receiving a placebo. To put things in perspective though, the 68 per cent improvement was relative not absolute. So basically, while there were four strokes (per 100-patient years) in the placebo group there was 1.5 in the warfarin group. The incidence of major bleeding events in the warfarin group was substantially higher.
Medical researchers at the University of Bristol now report that warfarin therapy has very little, if any, advantage over the daily aspirin ritual in the prevention of stroke in patients with non-rheumatic atrial fibrillation. The researchers carefully evaluated the results of five trials comparing aspirin and warfarin. They conclude that patients with non-rheumatic atrial fibrillation may not derive any greater protection against stroke and cardiovascular death with long-term anticoagulation than with aspirin therapy. They also point out that major bleeding events were 45 per cent more common in patients who received warfarin. Their final conclusion was "Given the uncertainty over the greater efficacy of anticoagulation, its undoubted hazards, and considerations of cost effectiveness we would strongly favour antiplatelet drugs (aspirin) in preference to long term anticoagulation (warfarin)".
Taylor, F.C., et al. Systematic review of long term anticoagulation or antiplatelet treatment in patients with non-rheumatic atrial fibrillation. British Medical Journal, Vol. 322, February 10, 2001, pp. 321-26