Anticoagulant Therapy in Atrial Fibrillation – Time for a Change?

Although to date warfarin and other vitamin K antagonists have clearly had the greatest efficacy among commonly available treatments in preventing stroke in atrial fibrillation, their use is associated with a substantial risk of major bleeding and is impractical because of their narrow therapeutic window, their interaction with drugs and foods and the need for frequent coagulation monitoring. Several new anticoagulants are undergoing phase III clinical trials in atrial fibrillation with the aim of demonstrating non-inferiority compared with vitamin K antagonists or superiority compared with aspirin in patients in whom vitamin K antagonists are contraindicated or not tolerated. In the recently released Randomized Evaluation of Long-Term Anticoagulation Therapy (RE-LY) trial, the first such drug, dabigatran etexilate, was proved substantially equivalent to 2–3 international normalised ratio (INR)-adjusted warfarin at the dosage of 110mg twice a day (BID), with superior efficacy at a dosage of 150mg BID. With these new drugs, cardiologists and internists are witnessing a real revolution in the thromboprophylaxis in atrial fibrillation.