Atrial fibrillation and dabigatran: has the time come to use new anticoagulants?

Atrial fibrillation (AF) is the most common sustained cardiac rhythm disturbance found in clinical practice, increasing in prevalence with age. AF is often associated with structural heart disease, although a significant proportion has no detectable heart disease. In the last 2 decades, there has been an increase of 66% in hospitalizations for AF, and it is an extremely costly public health problem. AF is associated with an increased long-term risk of stroke, heart failure, and all-cause mortality. In fact, the mortality rate in patients with AF is about double that of patients in normal sinus rhythm. Antithrombotic therapy is recommended for all patients with AF to prevent thromboembolism, except those with lone AF or contraindications. Selection of the antithrombotic agent should be based upon the absolute risks of stroke and bleeding and the relative risk and benefit for a given patient. However, despite oral anticoagulation with vitamin K antagonists (warfarin or acenocoumarol) some patients still have thromboembolic events. Furthermore, for the majority of patients, international normalized ratio (INR) monitoring may be an inconvenience. This is why new anticoagulants, such as the direct thrombin inhibitors, are being investigated. The results of the RE-LY trial have recently been published. In this study, in a population of patients with AF, dabigatran at 110 mg b.i.d was associated with stroke and systemic embolism rates similar to those associated with warfarin, and with lower rates of major hemorrhage. However, when dabigatran was administered at a dose of 150 mg, lower rates of stroke and systemic embolism and similar rates of major hemorrhage were found compared with warfarin. The aim of this review is to update information on the prevention of thromboembolic events in patients with AF and how dabigatran may change daily clinical practice.