Warfarin is the treatment of choice for elderly patients with AF
Thromboembolic risk stratification in patients with atrial fibrillation (AF) has come increasingly to the fore over the past few years with the publication of NICE guidelines and the new QOF indicators.
It is generally accepted that warfarin is superior to aspirin for the prevention of thromboembolic events in patients with AF. However, most of the trials to date have enrolled younger patients with an inherently lower risk of bleeding complications.
As the majority of cerebrovascular events occur in the over 75s, it makes sense to look at the pros and cons of warfarin in this group, particularly in primary care, where some of the earlier trials have not been encouraging.
A new trial has now found evidence to support the use of warfarin as the antithromboembolic of choice for patients aged over 75 years in primary care.
BAFTA was a randomised, controlled trial comparing adjusted-dose warfarin with a target INR of 2.5 (range 2.0-3.0) with aspirin 75 mg daily. A total of 973 patients aged ? 75 years were enrolled from 260 practices in England and Wales.
Patients were followed up every six months for a mean of 2.7 years. The primary end point was fatal or nonfatal disabling ischaemic or haemorrhagic stroke, intracranial haemorrhage or significant arterial embolism.
There was a significant reduction in the risk of a primary outcome event in the warfarin group, with an annual risk of 1.8% compared with 3.8% in the aspirin group (relative risk 0.48, 95% CI=0.28-0.80).
Furthermore there was no significant increase in bleeding complications in the warfarin group, with a major haemorrhage event rate of 1.9% per annum compared with 2.0% per annum in the aspirin group (relative risk 0.96, 95% CI=0.53-1.75).
This trial provides further evidence for the use of warfarin as the antithromboembolic measure of choice in elderly AF patients unless there is a compelling reason not to anticoagulate.
Mant J, Hobbs FDR, Fletcher K et al. Warfarin versus aspirin for stroke prevention in an elderly community population with atrial fibrillation (the Birmingham Atrial Fibrillation Treatment of the Aged Study, BAFTA): a randomised controlled trial. Lancet 2007;370:493-503Reviewer
Dr Peter Savill
GPSI Cardiology, Southampton