The aim of the study was to investigate the role of chronic kidney disease (CKD) on in-hospital mortality and on incident atrial fibrillation (AF) in patients infected with SARS-CoV-2. The incidence of acute kidney injury (AKI) was also investigated. Multivariable regression models were used to assess the association between renal function groups (estimated Glomerular Filtration Rate, eGFR, >60 mL/min, 30-59 mL/min, <30 mL/min) and in-hospital all-cause mortality and incident AF and AKI. A cohort of 2816 patients admitted in one year for COVID-19 disease in two large hospitals was analyzed. The independent predictors of mortality were severe CKD [HR 1.732 (95%CI 1.264-2.373)], older age [HR 1.054 (95%CI 1.044-1.065)], cerebrovascular disease [HR 1.335 (95%CI (1.016-1.754)], lower platelet count [HR 0.997 (95%CI 0.996-0.999)], higher C-reactive protein [HR 1.047 (95%CI 1.035-1.058)], and higher plasma potassium value 1.374 (95%CI 1.139-1.658). When incident AKI was added to the final survival model, it was associated with higher mortality [HR 2.202 (1.728-2.807)]. Incident AF was more frequent in patients with CKD, but in the multivariable model only older age was significantly related with a higher incidence of AF [OR 1.036 (95%CI 1.022-1.050)]. Incident AF was strongly associated with the onset of AKI [HR 2.619 (95%CI 1.711-4.009)]. In this large population of COVID-19 patients, the presence of severe CKD was an independent predictor of in-hospital mortality. In addition, patients who underwent AKI during hospitalization had a doubled risk of death. Incident AF became more frequent as eGFR decreased and it was significantly associated with the onset of AKI.
Keywords: COVID-19; acute kidney injury; atrial fibrillation; chronic kidney disease; mortality.