Use of warfarin in non-rheumatic atrial fibrillation: a commentary from general practice.

Seven randomized trials published in the last six years have shown that warfarin reduces the risk of ischaemic strokes and death in patients with atrial fibrillation. The annual rates of major bleeding episodes in all these trials were low and, as a result, doctors in primary and secondary care are being encouraged to consider using warfarin for patients with atrial fibrillation unless there are obvious contraindications. However, the populations used in these studies were highly selected and rigorously monitored throughout the trial period to minimize the risk of bleeding in a way which probably could not be expected in routine primary care. Although the rates of major bleeding episodes were uniformly low, the rates of minor bleeding episodes were much higher and these could impact substantially on patients' views of the treatment and on the workload of the primary care team. Evidence is now at hand which allows the stratification of risk in patients with atrial fibrillation which should enable those who are at greatest risk to be considered for this form of treatment. Patients may develop risk factors over time which could render them unsuitable for continuation of warfarin therapy. The general practitioner is centrally placed to make the decision about initiating or continuing treatment or indeed stopping it. Several models for decision making in warfarin treatment from primary and secondary care are proposed.