Anticoagulation and atrial fibrillation

Editor,—We would like to congratulate McNulty and colleagues on their excellent clinical audit of antithrombotic therapy in atrial fibrillation.1 Their approach to the methods of audit has been impeccable, completing the audit cycle by instigating a process of reaudit after the results from the original data set had been intensively presented to hospital colleagues, itself leading to a highly effective intervention. We would, however, appreciate this opportunity to provide a brief update in a few aspects of the current knowledge of stroke prevention in atrial fibrillation. The Lip and Lowe algorithm used for risk stratification was first published in 19962 and a refinement has since been proposed (box 1),3 which has been adapted for use in local and national guidelines.#### Box 1: Risk stratification and anticoagulation in non-valvular atrial fibrillation ##### ASSESS RISK AND REASSESS REGULARLY: (1) : High risk (annual risk of CVA = 8%–12%) • : All patients with previous transient ischaemic attack or CVA. • : All patients aged 75 or over with diabetes and/or hypertension. • : All patients with clinical evidence …