Abstract 18795: Non-vitamin K Oral Anticoagulants Are Non-inferior for Stroke Prevention but Cause Fewer Major Bleedings Than Well-managed Warfarin With Time in Therapeutic Range 70% or Higher in Sweden

Introduction: For patients with atrial fibrillation (AF), non-vitamin K oral anticoagulants (NOACs) (dabigatran, rivaroxaban, and apixaban) have been proven non-inferior or superior to warfarin in preventing stroke and systemic embolism, and in risk of hemorrhage. However, in the pivotal studies the quality of warfarin (control) treatment was low, with mean time in therapeutic range (TTR) 55% to 64%. This is to be compared to Swedish clinical practice with TTR≥70 %.Aim: To elucidate if NOACs compared to everyday warfarin treatment in Sweden, with TTR≥70%, are superior in preventing thromboembolic events and cause fewer major bleedings.Methods: We studied all 12,694 patients with AF starting NOAC treatment within the Swedish clinical register for AF (Auricula) from July 1, 2011 to December 31, 2014. Auricula registers all oral anticoagulation treatments within its more than 200 anticoagulation clinics and primary health care centers, excluding no patient groups. Patients were matched to 36,317 controls (patients with AF starting warfarin), using propensity scoring. Outcome data were collected from validated Swedish hospital administrative and clinical registers.Results: Results are given for NOACs and warfarin, respectively. Mean age was 72.2 vs. 72.3 years. Proportion of males was 58.2% and 57.0%. Mean follow-up time was 299 vs. 285 days. Distribution of NOACs was: dabigatran 40.3%, rivaroxaban 31.2%, and apixaban 28.5%. Mean TTR for warfarin treated patients was 70%. Absolute risks of outcomes with hazard ratios are given in Table 1.Conclusions: In Swedish clinical practice for patients with AF, NOACs do not prevent thromboembolic events better than well-managed warfarin, but they do confer significantly lower risk of major bleeding, particularly intracranial bleeding. In conclusion, NOACs should be the preferred choice of oral anticoagulation for stroke prevention in patients with AF, even in a clinical setting with warfarin mean TTR ≥70%.