QT interval and repolarization dispersion changes during the administration of hydroxychloroquine/chloroquine with/without azithromycin in early COVID 19 pandemic: A prospective observational study from two academic hospitals in Indonesia

Background: Hydroxychloroquine/chloroquine (HCQ/CQ) treatment for COVID-19 was associated with QT interval prolongation and arrhythmia risks. This study aimed to investigate QTc interval and ventricular repolarization dispersion changes, as markers of arrhythmia risks, after HCQ/CQ administration with/without azithromycin (AZT) during COVID-19 pandemic. Methods: A prospective observational study was performed in two academic hospitals in Indonesia. Adult patients who received HCQ/CQ alone and HCQ/CQ + AZT concomitant treatments for COVID-19 infection were enrolled. Baseline and post HCQ/CQ treatment electrocardiograms were obtained. Baseline and post HCQ/CQ treatment QT interval by Bazett (B-QTc) and Fridericia (F-QTc) formulas and ventricular repolarization dispersion indices by Tpeak-Tend (Tp-e) interval and Tpeak-Tend/QT (Tp-e/QT) ratio were calculated and analyzed. Results: The study enrolled 55 (HCQ/CQ alone) and 77 subjects (HCQ/CQ + AZT concomitant). F-QTc interval significantly lengthened in subjects with HCQ/CQ + AZT (mean difference 11.89 ms P =.028). The incidences of severe B-QTc and F-QTc lengthening were 13.1% and 12.3%, B-QTc and F-QTc prolongation were 25.4% and 12.3%, and severe B-QTc and F-QTc prolongation were 6.2% and 3.2%. Tp-e interval lengthened significantly from baseline to posttreatment in HCQ/CQ alone and HCQ/CQ + AZT (mean difference 10.83 ms P =.006 and 18.73 ms P <.001, respectively). Tp-e/QT ratio increased significantly from baseline to posttreatment in HCQ/CQ + AZT concomitant (mean difference 0.035 P <.001). No fatal arrhytmia occurred. Conclusions: During COVID-19 pandemic, HCQ/CQ + AZT concomitant treatment caused significant F-QTc lengthening, significantly increased Tp-e interval and increased Tp-e/QT ratio. HCQ/CQ alone only caused significant increase of Tp-e interval. Incidences of severe QTc lengthening and prolongation were low in both HCQ/CQ alone and HCQ/CQ + AZT concomitant. © 2021 The Authors. Journal of Arrhythmia published by John Wiley & Sons Australia, Ltd on behalf of Japanese Heart Rhythm Society