Prolongation of the QTc Interval at Admission is Associated with Increased Mortality in Patients with SARS-COV-2 during Hospitalization

Background: Cardiovascular involvement associated with SARS-COV-2 infection is related to unfavorable outcomes during hospitalization. Therefore, the measurement at the admission of the QTc interval on the 12-lead electrocardiogram may be a prognostic marker. Objective: To identify the relationship between QTc prolongation at admission during hospitalization and mortality from SARS-COV-2. Method: Observational study based on a retrospective cohort of patients with confirmed SARS-COV-2 infection from San Ignacio University Hospital, Bogotá (Colombia), between March 19, 2020, and July 31, 2021. Mortality was compared in patients with prolonged and normal QTc at admission after controlling by clinical variables and comorbidities using bivariate and multivariate logistic regression models. A p-value <0.05 was considered statistically significant. Results: 1296 patients were analyzed, and 127 (9.8%) had prolonged QTc. Mortality was higher in patients with prolonged QTc (39.4% vs 25.3%, p=0.001), as was hospital stay (median 11vs.8 days; p=0.002). In the multivariate analysis, mortality was associated with prolonged QTc (OR 1.61, 95% CI: 1.02; 2.54, p=0.038), age (OR 1.03, 95% CI 1.02; 1.05, p<0.001), male sex (OR 2.15, 95% CI 1.60; 2.90, p <0.001), kidney disease (OR 1.32, 95% CI 1.05; 1.66, p =0.018) and Charlson comorbidity index > 3 (OR 1.49, 95% CI 1.03; 2.17, p=0.035). Conclusions: Hospital mortality due to SARS-COV-2 is associated with prolonging the QTc interval at the time of admission, even after adjusting for age, sex, comorbidities, and basal severity of infection. Additional research is needed to establish whether these findings are related to cardiac involvement by the virus, hypoxia, and systemic inflammation.