Long-term outcome and risk factors associated with events in patients with atrial fibrillation treated with oral anticoagulants: The ASSAF-K registry

Abstract

BackgroundOral anticoagulant therapy for atrial fibrillation (AF) has changed dramatically. Direct oral anticoagulant (DOAC) therapy is administered by general practitioners and specialists. However, the beneficial long-term effects and safety of DOACs have not been well investigated in real-world clinical practice. MethodsThe ASSAF-K (a study of the safety and efficacy of OAC therapy in the treatment of AF in Kanagawa), a prospective, multi-center, observational study, was conducted to clarify patient characteristics, status of OAC treatment, long-term outcomes, and adverse events, including cerebrovascular disease, bleeding, and death. ResultsA total of 4014 patients were enrolled (hospital: 2500 cases; clinic: 1514 cases). The number of patients in the final dataset was 3367 (mean age, 72.6 ± 10.0 years; males, 66.3 %). CHA2DS2-VASc and HAS-BLED scores were 3.0 ± 1.6 and 2.2 ± 1.0, respectively. The risk factors of the primary composite outcome (all-cause death, serious bleeding events, cerebral hemorrhage, and stroke) were higher age, lower body mass index, lower diastolic blood pressure, lower creatine clearance, history of heart failure, history of stroke, and medication of anti-platelet agents. The event-free rates of the primary composite outcome with DOACs, warfarin, and without OACs were 92.7 %, 88.0 %, and 87.4 %, respectively. The event rate of DOACs was significantly lower than that of warfarin [HR 0.63 (95 % CI 0.48–0.81)], and similar results were observed after adjustment for AF stroke risk score [HR 0.70 (95 % CI 0.54–0.90)]. Serious bleeding events tended to occur less frequently with DOACs compared with warfarin [unadjusted HR 0.53 (95 % CI 0.31–0.91), adjusted HR 0.61 (95 % CI 0.33–1.11)]. ConclusionsThis multi-center registry demonstrated the long-term outcome in patients with AF treated with and without OACs and suggests that DOAC therapy is safe and beneficial in hospitals and clinics.