Comorbidities in Patients with Atrial Fibrillation : A Nationwide Cohort Study -TRAF (TuRkish Atrial Fibrillation data base) Bünyamin Yavuz, Keçiören Training and Res Hosp, Ankara, Turkey; Emre Oto, MITS, Ankara, Turkey; Naim Ata, Social Security Inst, Ankara, Turkey; Banu Evranos, Private Akay Hospital, Ankara, Turkey; Deniz Katırcıoglu Öztürk, MITS, Ankara, Turkey; Uğur Canpolat, Yuksek Ihtısas Training and Res Hosp, Ankara, Turkey; Kudret Aytemir, Hacettepe University of Medical School, Ankara, Turkey; Altay Güvenir,Bılkent University Computer Engineering Department, Ankara, Turkey; Ergun Karaagaoglu,Hacettepe Univ of Medical School, Ankara, Turkey; Emre Ertugay, Rasim Koselerli, Abdülkadir Bürkan, Mustafa Kuruca, Yadigar Gokalp Ilhan, Social Security Inst, Ankara, Turkey; John Camm, St. George's University of London, London, United Kingdom; Ali Oto, Hacettepe Univ of Medical School, Ankara, Turkey Background: Atrial fibrillation (AF) is the most common sustained cardiac arrhytmia and it is also associated with many comorbidities. This study aims to investigate the prevalence of comorbidities among patients with non-valvular atrial fibrillation in order to define a more comprehensive picture of total disease burden in a large cohort. Methods: We analyzed the records of 542,130 patients over the age 18 who had the diagnosis of non-valvular AF according to ICD-10 code I48 from a nation-wide claims and utilization management system called MEDULA which processes claims for all health insurance funds in the country since 2007. Covering close to 100 % of the population, MEDULA is comprised of pharmacy, inpatient, outpatient and laboratory claims and covers 23,500 pharmacies, 20,000 general practitioners, 850 government hospitals, 60 university hospitals and 500 private hospitals. In this study we have used completely anonymized data. Results: 402,674 patients have been diagnosed with non-valvular atrial fibrillation (mean age 68,3 years, 44,2% men). Hypertension was the most prevalent comorbidity, affecting 77,5 % of the patients evaluated. Other prevalent comorbidities were; heart failure (40,2 %), chronic obstructive pulmonary disease ( 29,1 %), diabetes (20,3 %), history of myocardial infarction (7,8 %) and chronic kidney disease (9.1%). When we analyzed the data pertaining to patients over age 65 ; we found that 66 % had DM, 67.5 % had HT, 76.7% had COPD, 78.9% had chronic kidney disease, 70.8% had peripheric vascular diease, 77.5% had heart failure, and 66.5% had MI. Conclusions: TRAF study indicates a high prevalence of comorbidities among patients with AF. To our knowledge the prevalance of comorbidities in the elderly patients is the highest in the literature. Some of these prevalent comorbidities are also risk factors for thromboembolism and complicate the atrial fibrillation management. Therefore physicians should carefully consider comorbidities when handling elderly patients with AF.