ABSTRACT
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.
ABSTRACT
Background: Growth differentiation factor-15 (GDF-15) is a strong predictor of bleeding in atrial fibrillation (AF) patients. The novel ABC (age, biomarkers, and clinical history), AF, and bleeding risk score outperforms HAS-BLED bleeding risk score for major bleeding (MB) in patients with AF receiving oral anti-coagulation in the clinical trial cohort. However, it has not been entirely externally validated. We aimed to refine and understand the application of the ABC-AF bleeding risk score in elderly (aged ≥65 years old) patients with nonvalvular atrial fibrillation (NVAF) for predicting the different types of bleeding events and anti-thrombotic treatments. Methods: We identified elderly patients with NVAF between March 2018 and December 2019 who were hospitalized for the first time after a diagnosis of NVAF. We measured the plasma concentration of the ABC biomarkers (growth differentiation factor 15 (GDF-15) and cardiac troponin-T (cTnT)) from enrolled patients. We collected their general information and follow up for one year until December 2020. During the follow-up period, information on the occurrence of bleeding events (major bleeding, clinically relevant nonmajor gastrointestinal bleeding (CRNM GIB), and minor bleeding events) was collected. Results: We enrolled 342 elderly NAVF patients; the ABC-AF bleeding and HAS-BLED scores were quantified. With an average of 1.5 years of follow-up, 6 patients had an intracranial hemorrhage; 57 patients had CRNM GIB; and 68 patients had minor bleeding events (36 fecal occult blood positive and 32 other minor bleeding events). The ABC-AF bleeding score yielded a C-index of 0.72 (95% CI 0.60-0.84) for predicting MB in elderly patients with NAVF, C-index of 0.69 (95% CI 0.57-0.82) by HAS-BLED score. Comparison of the incidence of bleeding events during follow-up and the predicted 1-year incidence of bleeding events by each bleeding risk score, ABC-AF bleeding, and HAS-BLED scores have similar value in predicting the risk for elderly patients with NAVF in different types of bleeding events, whether on oral anti-coagulation treatment (OAC) or non-OAC (P > 0.05). Conclusion: In elderly patients with NVAF, the biomarker-based ABC-AF bleeding score showed similar performance compared with the HAS-BLED bleeding risk score.
