Comparison of primary and secondary stroke prevention in patients with nonvalvular atrial fibrillation: Results from the RAFFINE registry

Abstract

ObjectivesClinical outcome data of primary and secondary prevention in patients with nonvalvular atrial fibrillation (NVAF) after the introduction of direct oral anticoagulant (DOAC) therapy are limited. Materials and MethodsA subgroup analysis of the RAFFINE registry, an observational, multicenter, prospective registry of Japanese patients with AF, was performed. Incidence rates of stroke or systemic embolism, all-cause death, major bleeding, and intracranial hemorrhage were compared between patients with and without a history of stroke or transient ischemic attack (TIA). ResultsOf 3,706 NVAF patients at baseline, 557 (15.0%) had a history of ischemic stroke or TIA (secondary prevention group), and 3,149 (85.0%) had no history of ischemic stroke or TIA (primary prevention group). The proportion of patients receiving oral anticoagulants was 87.2% (42.5% warfarin, 44.7% DOACs). The secondary prevention group had higher rates of stroke or systemic embolism (2.6% vs 1.0%/year, p<0.001), all-cause death (3.6% vs 2.4%/year, p<0.01), and major bleeding (2.0% vs 1.3%/year, p<0.01), and similar rates of intracranial hemorrhage (0.6% vs 0.5%/year, p=0.66) compared with the primary prevention group. A Cox proportional hazards model showed that a history of ischemic stroke or TIA was independently associated with an increased risk of stroke or systemic embolism (adjusted hazard ratio, 2.22; 95% confidence interval, 1.57 – 3.15; p<0.001). ConclusionsIn a contemporary cohort of NVAF patients, a history of ischemic stroke or TIA was still an independent predictor of stroke or systemic embolism, despite advances in anticoagulation therapy.