Atrial fibrillation and COVID-19 in older patients: a complex, dangerous, association. An analysis of the GeroCovid Registry

Introduction. Atrial fibrillation (AF) is the most frequent arrhythmia diagnosed in elderly patients. It often associates with disabling complica- tions, such as stroke and systemic embolism. COVID-19 severely affects older subjects, who show a particularly high mortality, often related to relevant alterations in coagulation and inflammation cascade. Purpose. Aim of this study was to evaluate how the presence of a prevalent form of AF (at admission or in clinical history) influenced the clinical course of COVID-19 in an aged in-hospital population. Methods. We studied the acute patients included in GeroCovid, a multicenter retrospective-prospective registry designed by the Italian Soci- ety of Gerontology and Geriatric Medicine and the Norwegian Geriatrics Society. GeroCovid, independently of the healthcare setting and without exclusion criteria, enrolled subjects aged >60 years to analyze risk factors, signs, symptoms and outcomes of COVID-19 in older people. For the purpose of this study, only the acute, in-hospital, cohort was evaluated. Results. Between March 1st and June 6th 2020, 2474 patients were enrolled in GeroCovid. Of these, 806 (32.6%) were assisted in hospital, for an acute condition (age: 79 ± 9 years; men: 51.7%). The prevalence of AF was 21.8%. Patients with the arrhythmia were older (82 ± 8 vs. 77 ± 9 years; p < 0.001) and with a higher CHA2DS2-VASc score (4.1 ± 1.5 vs. 3.2 ± 1.5; p < 0.001). The prevalence of almost all comorbidi- ties was higher in AF patients (in particular, hypertension, cardiac diseases, diabetes, heart failure, peripheral artery disease, chronic renal failure, COPD, stroke, obesity). At multivariable analysis, advanced age (p = 0.010), an increased number of white blood cells (p = 0.031), the presence of cardiac diseases (p < 0.001), peripheral artery disease (p = 0.030) and of signs or symptoms of heart failure (p = 0.003) char- acterized older patients with AF. In-hospital mortality was significantly higher in patients with the arrhythmia (36.9 vs. 27.5%; OR = 1.55, 95%CI = 1.09-2.20; p = 0.015). A multivariable logistic regression model showed that AF was an independent predictor of mortality (p = 0.021), such as male gender (p = 0.014) and the presence of peripheral artery disease (p = 0.003). COPD, stroke, chronic renal failure, dia- betes and obesity were deleted from the final model. Conclusions. AF is frequently observed in older patients with COVID-19. Subjects with both conditions have a more complex clinical status and show a higher in-hospital mortality, thus requesting a particularly careful and intensive management.