COVID-19 and atrial fibrillation in older patients. Does oral anticoagulant therapy provide a survival benefit? An insight from the GeroCovid Registry

Introduction. Atrial fibrillation (AF), the most frequent arrhythmia of older patients, associates with serious thrombo-embolic complications and high mortality. COVID-19 severely affects aged subjects, determining an important prothrombotic status. Aim of this study was to evaluate mortality-related factors in older AF patients with COVID-19. Methods. Between March and June 2020, we enrolled >=60 years in-hospital COVID-19 patients (N=806) in GeroCovid, a multicenter observational study promoted by the Italian Society of Gerontology and Geriatric Medicine. Results. The prevalence of AF was 21.8%. In-hospital mortality was higher in the AF group (36.9 vs. 27.5%, p=0.015). At admission, 51.7%, 10.2% and 38.1% of AF cases were taking, respectively, oral anticoagulants (OACs), antiplatelet agents and no antithrombotic therapy. During hospitalization, 51% patients switched to low-molecular weight heparins. AF patients who survived were younger (81±8 vs. 84±7 years; p=0.002) and had a lower CHA2DS2-VASc score (3.9±1.6 vs. 4.4±1.3; p=0.02) than those who died. OACs use before (63.1% vs. 32.3%; p<0.001) and during hospitalization (34.0% vs. 12.7%; p=0.002) was higher among survivors. At multivariable analysis, lower age, higher self-sufficiency, less severe initial COVID-19 presentation, and the use of Vitamin K antagonists (OR=0.16, 95%CI: 0.03-0.84) or DOACs (OR=0.22, 95%CI: 0.08-0.56) at admission, or the persistence of OAC during hospitalization (OR=0.05, 95%CI: 0.01-0.24), were associated with a lower chance of in-hospital death. Conclusions. AF is a prevalent and severe condition in older COVID-19 patients. Advanced age, dependency and relevant clinical manifestations of disease characterized a worse prognosis. Pre-admission and in-hospital anticoagulant therapy were positively associated with survival.