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

Objectives: Clinical 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 Methods: A 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).

Results: Of 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).

Conclusions: In 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.