The Efficacy and Safety of NOAC in Very Elderly Atrial Fibrillation Patients: Data From the Korean National Health Insurance Cohort Registry

Abstract

Background and Objectives: We investigated the clinical benefit of anticoagulation with non-vitamin K antagonist oral anticoagulant (NOAC) in very elderly atrial fibrillation (AF) patients through national healthcare insurance registry. Methods: Clinical data was acquired from the National Health Insurance Service of south Korea. Medical records of 862,935 patients who were diagnosed with AF from 2015 to 2020 were collected for analysis. Patients under the age of 85, prior history of intracranial hemorrhage, gastrointestinal bleeding and prior prescription days of aspirin, warfarin or NOAC exceeding 90 along with follow up period less than 90 days were excluded. Results: A total of 10,625 patients were eligible for analysis. Patients with oral anticoagulant (hazard ratio [HR], 0.60, 95% confidence interval [CI], 0.53–0.69, p<0.001) showed higher efficacy regarding cerebrovascular accident (CVA) compared to aspirin (HR, 0.84, 95% CI, 0.74–0.95, p=0.008) and no treatment group. Individual comparison of NOAC and aspirin via propensity score matching showed that patients with NOAC (HR, 0.71, 95% CI, 0.61–0.85, p<0.001) showed higher event free survival regarding CVA compared to aspirin. Bleeding risk was also higher for NOAC (HR, 1.28, 95% CI, 1.07–1.56, p=0.006) group but did not result in commensurate increase in mortality (HR, 0.60, 95% CI, 0.45–0.81, p<0.001). Conclusions: Anticoagulation with NOAC in very elderly patient showed higher event free survival regarding CVA. Despite having higher event rate of bleeding, eventual death was lower for NOAC.