Epidemiology of atrial fibrillation in Turkey: preliminary results of the multicenter AFTER study

We congratulate the authors of the paper titled “Epidemiology of atrial fibrillation in Turkey: preliminary results of the multicenter AFTER study”, which evaluated 2242 consecutive patients with at least one atrial fibrillation (AF) in 17 different tertiary health care centers.[1] However, we have a few concerns about the study: 1. The efficacy and safety of warfarin anticoagulation in patients with AF are dependent on the intensity of anticoagulation measured as the international normalized ratio (INR). The risk of ischemic stroke increases with INR levels <1.8, and the risk of intracranial hemorrhage increases at INR levels >3.5.[2] These findings support the standard “therapeutic” INR range for AF of 2.0-3.0. A commonly used summary of the quality of warfarin anticoagulation is the linearly interpolated percent time in the therapeutic range (TTR). TTR must be >65% for a better anticoagulation.[3] According to the report from the ACTIVE W trial, if the TTR.