Factors for recurrent stroke among Asian patients with non-valvular atrial fibrillation under non-vitamin K antagonist oral anticoagulant therapy

BACKGROUND/PURPOSE: Atrial fibrillation (AF) patients with a history of ischemic stroke or transient ischemic attack (TIA) carry excessive risk of recurrent stroke. Real-world data for the Asian population is scarce. This study aimed to investigate the thromboembolism and major bleeding risk of non-vitamin K antagonist oral anticoagulant (NOAC) therapy among Asian patients, and to identify the risk factors of recurrent stroke. METHODS: This retrospective study recruited AF patients aged over 20 years, who had a previous stoke or TIA, and received NOAC therapy. Thromboembolic events were recurrent ischemic stroke or TIA, and the major bleeding events were classified according to the PLATO (Platelet Inhibition and Patient Outcomes) criteria. RESULTS: A total of 361 patients (61.2% male) were enrolled for data analysis. The incidence rate for recurrent ischemic stroke or TIA was 3.6 (95% CI = 2.5 to 5.5) per 100 person-years, and 0.9 (95% CI = 0.4 to 1.7) per 100 person-years for major bleeding. Patients with recurrent ischemic stroke or TIA were more likely to have malignancy (hazard ratio [HR] for malignancy = 4.4, 95% CI = 1.9 to 10.3, p = 0.001) and concomitantly take enzyme inducing antiepileptic drugs (EIAED, HR = 8.1, 95% CI = 2.7 to 24.1, p < 0.001). CONCLUSION: Atrial fibrillation patients with underlying malignancy or concurrently use of EIAED may have increased risk of treatment failure in secondary stroke prevention.