Thromboembolism, bleeding and vascular death in nonvalvular atrial fibrillation patients with type 2 diabetes receiving rivaroxaban or warfarin

BACKGROUND: Diabetes increases a patient's risk of developing atrial fibrillation by 49%. Patients with nonvalvular atrial fibrillation are at a fivefold increased risk of stroke and die more frequently from vascular causes. We sought to evaluate the effectiveness and safety of rivaroxaban versus warfarin in nonvalvular atrial fibrillation patients with type 2 diabetes. METHODS: This was an analysis of Optum® De-Identified electronic health record data from 11/2010 to 12/2019. We included adults with nonvalvular atrial fibrillation and type 2 diabetes, newly started on rivaroxaban or warfarin and with ≥ 12-months of prior electronic health record activity. Patients who were pregnant, had alternative indications for oral anticoagulation or valvular heart disease were excluded. We evaluated the incidence rate (%/year) of developing the composite outcome of stroke/systemic embolism or vascular death and major or clinically relevant nonmajor bleeding as well as each endpoint individually. Hazard ratios with 95% confidence intervals were calculated using propensity score-overlap weighted proportional hazards regression. RESULTS: We included 32,078 rivaroxaban (31% initiated on 15 mg dose) and 83,971warfarin users (time-in-therapeutic range = 47 ± 28%). Rivaroxaban was associated with a reduced risk of stroke/systemic embolism or vascular death (3.79 vs. 4.19; hazard ratio = 0.91, 95% confdience interval = 0.88-0.95), driven mostly by reductions in vascular death (2.81 vs 3.18, hazard ratio = 0.90, 95% confidence interval = 0.86-0.95) and systemic embolism (0.13 vs. 0.16; hazard ratio = 0.82, 95% confidence interval = 0.66-1.02). Major/clinically relevant nonmajor bleeding was less frequent with rivaroxaban versus warfarin (2.17 vs. 2.31; hazard ratio = 0.94, 95% confidence interval = 0.89-0.99) due to decreased critical organ bleeding (including intracranial hemorrhage) (0.35 vs. 0.54; hazard ratio = 0.63, 95% confidence interval = 0.55-0.72). CONCLUSIONS: In nonvalvular atrial fibrillation patients with type 2 diabetes, rivaroxaban was associated with an ~ 10% relative reduction in vascular mortality and fewer bleeding-related hospitalizations versus warfarin.