An Epidemiological Study to Evaluate the Use of Vitamin K Antagonists and New Oral Anticoagulants Among Nonvalvular Atrial Fibrillation Patients in Turkey

Atrial fibrillation (AF) is the most common cause of preventable stroke and strongly associated with increased cardiovascular morbidity and mortality with a prevalence of 1-2% in general population.The first multicenter trial in AF patients in our country, Atrial Fibrillation in Turkey: Epidemiologic Registry (AFTER) study, showed that 40% of non-valvular AF patients were on warfarin therapy with an effective INR rate of 37% and the most frequent cause of warfarin underuse was physician neglect. Yet, the use of new oral anticoagulants, time in therapeutic INR range (TTR) in warfarin users and the main management modality (rhythm or rate control) in AF patients have not been studied in Turkey. Therefore, in this multicenter trial, we aimed to assess the extent of effective anticoagulant use (by means of TTR) and epidemiological characteristics of the nonvalvular AF patients with the use of new oral anticoagulants (NOACs) in clinical practice in addition to increased awareness provided by AFTER study.

AFTER-2 study is planned as a prospective, observational and multicenter study with a 6 month and 1-year follow-up of the patients. A total of 4100 patients in 42 centers reflecting the population of the twelve regions of our country according to the Nomenclature of Territorial Units for Statistics will be included in the study.

The detailed characteristics of the patients with non-valvular AF, the rates and kind of oral anticoagulant use, the effect of increased awareness and NOACs on anticoagulant use rate, TTR in warfarin using patients and the bleeding risks of the patients will be determined in this study. At the end of the study, we will question the patients in terms of major adverse events and analyze the independent predictors of these events.