Mortality risk factors in patients with SARS-CoV-2 infection and atrial fibrillation: Data from the SEMI-COVID-19 registry. / Factores de riesgo de mortalidad en pacientes con infección por SARS-CoV-2 y fibrilación auricular: datos del registro SEMI-COVID-19.

INTRODUCTION: Atrial fibrillation and associated comorbidities pose a risk factor for mortality, morbidity and development of complications in patients admitted for COVID-19. OBJECTIVES: To describe the clinical, epidemiological, radiological and analytical characteristics of patients with atrial fibrillation admitted for COVID-19 in Spain. Secondarily, we aim to identify those variables associated with mortality and poor prognosis of COVID-19 in patients with atrial fibrillation. METHODS: Retrospective, observational, multicenter, nationwide, retrospective study of patients hospitalized for COVID-19 from March 1 to October 1, 2020. Data were obtained from the SEMI-COVID-19 Registry of the Spanish Society of Internal Medicine (SEMI) in which 150 Spanish hospitals participate. RESULTS: Between March 1 and October 1, 2020, data from a total of 16,461 patients were entered into the SEMI-COVID-19 registry. 1816 (11%) had a history of atrial fibrillation and the number of deaths among AF patients amounted to 738 (41%). Regarding clinical characteristics, deceased patients were admitted with a higher heart rate (88.38 vs. 84.95; P>0.01), with a higher percentage of respiratory failure (67.2 vs. 20.1%; P<0.01) and high tachypnea (58 vs. 30%; P<0.01). The comorbidities that presented statistically significant differences in the deceased group were: age, hypertension and diabetes with target organ involvement. There was also a higher prevalence of a history of cardiovascular disease in the deceased. On multivariate analysis, DOACs treatment had a protective role for mortality (OR: 0.597; CI: 0.402-0.888; P=0.011). CONCLUSIONS: Previous treatment with DOACs and DOACs treatment during admission seem to have a protective role in patients with atrial fibrillation, although this fact should be verified in prospective studies.