Atrial fibrillation and coagulation: who and when?

Atrial fibrillation is an independent risk factor for stroke and is also associated with increased mortality above the age of 65 in both males and females. Various factors increase the stroke risk, with the most widely used risk assessment tool being the CHADS2 score which incorporates, heart failure, hypertension, age, diabetes and hitroys of previous stroke or transient ischaemic attack. Despite good evidence for the effectiveness of warfarin in preventing stroke and reducing mortality in atrial fibrillation, there remain a large proportion of patients who do not receive appropriate treatment. All patients with atrial fibrillation should be considered for warfarin therapy aiming for an INR of 2.5. Whilst newer agents may replace warfarin in the future, the evidence for anti-platelet therapy is poor and aspirin should be reserved only for patients who have very low stroke risk or those patients who cannot tolerate warfarin therapy.