Clinical profile of direct oral anticoagulants versus vitamin K anticoagulants in octogenarians with atrial fibrillation: a multicentre propensity score matched real-world cohort study

Atrial fibrillation (AF) is the most common arrhythmia in clinical practice and its prevalence increases with age. Few data are available about the clinical performance of direct oral anticoagulant (DOACs) in patients aged ≥ 80 years with AF. The aim of our propensity score matched cohort study was to compare the safety and efficacy of DOACs versus well-controlled VKA therapy among octogenarians with AF in real life setting. Data for this study were sourced from the multicenter prospectively maintained Atrial Fibrillation Research Database (NCT03760874), which includes all AF patients followed by the participating centers, through outpatient visits every 3 to 6 months. The database was queried for AF patients aged ≥ 80 years who received DOACs or VKAs treatment. The primary effectiveness endpoint was the occurrence of thromboembolic events (a composite of stroke, transient ischemic attack, systemic embolism); the primary safety endpoint was the occurrence of major bleeding; the secondary endpoint was all-cause mortality. The database query identified 774 AF patients aged ≥ 80 years treated with VKAs and 279 with DOACs. Propensity score (2:1) matching selected 252 DOAC and 504 VKA recipients. The mean follow-up was 31.07 ± 14.09 months. The incidence rate of thromboembolic events was 13.79 per 1000 person-years [14.80 in DOAC vs 13.34 in VKA group, Hazard Ratio 1.10; 95% confidence interval (CI) 0.49 to 2.45; P = 0.823]. The incidence rate of intracranial hemorrhage (ICH) was 8.06 per 1000 person-years (3.25 in DOAC vs 10.23 in VKA group, HR 0.33; 95% CI 0.07 to 1.45; P = 0.600). Through these incidence rates, we found a positive net clinical benefit (NCB) of DOACs over VKAs, equal to + 9.01. The incidence rate of all-cause mortality was 105.05 per 1000 person-years (74.67 in DOAC vs 118.67 in VKA group, Hazard Ratio 0.65; 95% CI 0.47 to 0.90; P = 0.010). The concomitant use of antiinflammatory drugs (HR 7.90; P < 0.001) were found to be independent predictor of major bleeding. Moreover, age (HR 1.17; P < 0.002) and chronic kidney disease (HR 0.34; P = 0.019) were found to be independently associated with thromboembolic events. In our study no significant difference in terms of both thromboembolic and major bleeding events, but a significant lower incidence of all-cause mortality, was detected in AF patients aged ≥ 80 years treated with DOACs vs VKAs