Anticoagulation: new challenges, old drugs.

Effective atrial fibrillation (AF) management requires attention to adequate rate control, consideration for the need to maintain sinus rhythm, and deliberation regarding proper anticoagulation to prevent thromboemboli. When properly used, warfarin anticoagulation in patients with AF at high risk for stroke reduces stroke incidence markedly. Unfortunately, proper anticoagulation with warfarin is not easy. An anticoagulant drug for which there are few interactions with other drugs, food, or supplements; for which there can be uniform dosing; for which routine International Normalized Ratio monitoring is not required; and for which there is a lower risk for bleeding, will gain widespread and rapid acceptance. In two large randomized trials comparing fixed-dose ximelagatran with warfarin in noninferiority studies, ximelagatran appears to be as effective at preventing stroke and thromboembolic events as warfarin (based on intention-to-treat analysis) and with similar, if not better, long-term risk.