Clinical features and outcomes of patients in different age groups with non-valvular atrial fibrillation receiving oral anticoagulants

Background: Patients with non-valvular atrial fibrillation (NVAF) need prophylactically antithrombotic therapies to reduce the risk of stroke. We hypothesized that the prognostic benefits of prophylactic antithrombotic therapies outweighed the bleeding risk among very elderly (≥85 years old) patients. Methods: We analyzed clinical characteristics and outcomes of patients with NVAF in different age groups who had received different prophylactic antithrombotic therapies. We enrolled 3895 consecutive NVAF patients in the Macau Special Administrative Region (Macau SAR) of China from January 1, 2010, to December 31, 2018. Among 3524 patients [including 1252 (35.53%) very elderly patients] who completed the entire study, 2897 (82.21%) patients had a CHA₂DS₂-VASc score ≥ 2, 2274 (64.53%) had HAS-BLED score < 3, and 1659 (47.08%) had both of the above. The follow-up time was 3.80 (median, interquartile range 1.89–6.56) years. The primary outcome was the first occurrence of ischemic stroke, major bleeding, clinically relevant non-major gastrointestinal bleeding (CRNM-GIB), and all-cause mortality. Results: A total of 2012 patients (57.09%) received no antithrombotic (NAT), 665 (18.87%) received antiplatelet (AP) agents, 371 (10.53%) received vitamin K antagonist (VKA), and 476 (13.51%) received non-vitamin K antagonist oral anticoagulants (NOACs). Eventually, 610 (17.31%) patients experienced thromboembolic events, with 167 (4.74%) strokes and 483 (13.71%) transient ischemia attack (TIA)/strokes. Bleeding events occurred in 614 (17.42%) patients, with 131 (3.72%) major bleeding, 381 (10.81%) CRNM-GIB and 102 (2.89%) minor bleeding events. All-cause deaths occurred in 483 (13.71%) patients. Compared with patients receiving NAT, patients receiving NOACs and VKA had fewer strokes (hazard ratio [HR]: 0.038; 95 %CI 0.004–0.401; p = 0.006 and HR: 0.544; 95 %CI 0.307–0.965; p = 0.037, respectively), and lower all-cause mortality (HR: 0.270; 95 %CI 0.170–0.429; p < 0.001 and HR: 0.531; 95 %CI 0.373–0.756; p < 0.001, respectively). Of note, very elderly patients with NVAF receiving NOACs had fewer strokes (adjust hazard ratio [_adjHR]: 0.042; 95 %CI 0.002–1.003; p = 0.050) and lower all-cause mortality (_adjHR: 0.308; 95 %CI 0.158–0.601; p = 0.001). Meanwhile, despite higher CRNM-GIB events (_adjHR: 1.736; 95 %CI 1.042–2.892; p = 0.034), major bleeding events (_adjHR: 1.045; 95 %CI 0.366–2.979; p = 0.935) did not significantly increase. VKA neither reduced strokes (_adjHR: 1.015; 95 %CI 0.529–1.948; p = 0.963), nor improved all-cause mortality (_adjHR: 0.995; 95 %CI 0.641–1.542; p = 0.981) in very elderly patients with NVAF. Conclusions: Antithrombotic treatment (VKA and NOACs) reduces stroke and improves prognosis in patients in different age groups with NVAF. The prognostic benefits of NOACs outweigh their bleeding risks in very elderly patients with NVAF.