Predictive factors for cardiac conduction abnormalities with hydroxychloroquine-containing combinations for COVID-19.

This longitudinal, prospective cohort study aimed to assess risk of QTc interval prolongation and its predicting factors in subjects treated with combinations containing hydroxychloroquine (HCQ) for COVID-19. Moderate-to-severe QTc prolongation during therapy was defined as a QTc interval >470 ms in men or >480 ms in women. Patients were treated under strict cardiac supervision. A total of 105 adults were included [56% male; median (IQR) age 69 (57-79) years]. All patients received therapy with HCQ in combination with azithromycin (AZM), and 95 (90%) also with lopinavir/ritonavir (LPV/r). Concomitant medications classified as having risk of developing torsades de pointes (TdP) were simultaneously used in 81 patients (77%). Moderate-to-severe QTc prolongation was observed in 14 patients (13%), mostly at Days 3-5 from baseline, with 6 (6%) developing severe prolongation (>500 ms). There was no evidence of TdP arrhythmia or TdP-associated death. Adding LPV/r to HCQ+AZM did not significantly prolong the QTc interval. Multivariable Cox regression revealed that comedications with known risk of TdP (HR = 11.28, 95% CI 1.08-117.41), higher neutrophil-to-lymphocyte (NLR) ratio (HR = 1.10, 95% CI 1.03-1.18 per unit increase) and higher serum hs-cardiac troponin I (HR = 4.09, 95% CI 1.36-12.2 per unit increase) were major contributors to moderate-to-severe QTc prolongation. In this closely screened and monitored cohort, no complications derived from QTc prolongation were observed during pharmacological therapy containing HCQ for COVID-19. Evidence of myocardial injury with elevated troponin and strong inflammatory response, specifically higher NLR, are conditions requiring careful QTc interval monitoring.