Impact of quality of anticoagulation control on outcomes in patients with atrial fibrillation taking aspirin: An analysis from the SPORTIF trials

Background: Concomitant aspirin(ASA) is often prescribed in anticoagulated patients with atrial fibrillation(AF). We aimed to investigate the relationship between ASA use and quality of anticoagulation control determining major adverse outcomes. Methods: An ancillary analysis of patients in the warfarin arm of the SPORTIF III and V trials was performed. Quality of anticoagulation control was defined using time in therapeutic range(TTR). Results: 3624 AF patients on warfarin were available for analysis: 1712(472%) were ASA non-users with good anticoagulation control(TTR >= 65%)[Group I], 380(10.5%) were ASA users with TTR >= 65%[Group II], 1192(32.9%) were ASA non-users with TTR< 65%[Group III] and 340(9.4%) were ASA users with TTR< 65%[Group IV]. CHA(2)DS(2)-VASc was similar across the groups(p = 0.350), conversely HAS-BLED was progressively higher(p< 0.001). At follow-up, stroke/systemic embolism rates were similar across the groups(p = 0.162). Conversely, a progressively higher rate for major bleeding was found(p = 0.034), as well as higher rates for all cause death in Group Ill and IV(p< 0.001). Kaplan-Meier analyses found a progressively higher risk for major bleeding across the groups(p = 0.005) and a higher all-cause death risk in Group III and IV(p< 0.001). Cox regression analysis confirmed that Group III and IV were at higher risk for major bleeding(p = 0.005) and all cause death(p = 0.010). Conclusions: Poor anticoagulation control is associated with higher bleeding risk, which is even greater with concomitant ASA use, with no difference in stroke/SE risk. Poor anticoagulation control is associated with a higher risk for all-cause death, independent of concomitant ASA use.(C) 2017 Elsevier B.V. All rights reserved.