The most recent metaanalysis by Hart et al (2007) concluded that when compared with control, adjusted-dose warfarin and antiplatelet agents reduced stroke by 64%(95% CI, 49% to 74%) and 22%(CI, 6% to 35%), respectively. Adjusted-dose warfarin was also more efficacious than antiplatelet therapy (relative risk reduction, 39% [CI, 22% to 52%]) (12 trials, 12 963 participants). The most recent comparison of warfarin versus aspirin comes from the Birmingham Atrial Fibrillation Treatment of the Aged Study (BAFTA) which showed that warfarin was more effective than aspirin for stroke prevention amongst elderly patients with AF, with no significant difference in major bleeding between warfarin and aspirin.
Despite the sound evidence from clinical trials and the many published guidelines, uptake of anticoagulation treatment in patients with AF is still suboptimal. Many reasons exist – these include patient centred factors, physician centred factors and health care system related factors – and all need efforts to address the different issues raised, in order that. Many patients dislike warfarin due to the inconvenience of monitoring, as well as food and drug interactions. Physicians are not good at stroke risk stratification, nor at estimating stroke or bleeding risks. Finally, health care systems need to have a holistic approach to educating the patient and physician, as well as appropriate facilities for anticoagulation monitoring, with support for hospital-based, home-based (or self monitoring) and/or point or care systems.
Gregory YH Lip, MD FRCP[Lond, Edin, Glasg] DFM FACC FESC, Professor of Cardiovascular Medicine, University Department of Medicine, City Hospital, Birmingham B18 7QH, England UK, g.y.h.lip(at)bham.ac.uk (July, 2008)