Impact of hydroxychloroquine and azithromycin on QTc in patients positive for COVID-19

Introduction: Hydroxychloroquine and azithromycin gained early popularity for treatment of Coronavirus Disease 2019 (COVID-19) following preliminary in-vivo data This combination regiment was considered to have high cardiac risk, primarily due to QTc prolongation The effect these medications have however, has not been quantified Research Question or Hypothesis: Does the addition of azithromycin increase QTc prolongation in COVID-19 patients treated with HCQ? Study Design: Single center retrospective review at a community hospital Methods: Adult patients with COVID-19 between 3/17 and 4/14/2020 who were treated with hydroxychloroquine with or without azithromycin were targeted Patients discontinued from treatment for non-cardiac reasons or not monitored on electrocardiography were excluded from the study The primary outcome was incidence of increased QTc, defined by the American College of Cardiology as a QTc increase of greater than 60 msec or absolute QTc greater than 500 msec Secondary outcomes included incidence of ventricular tachycardia, all-cause mortality, and change in QTc Data was assessed using descriptive statistics, Student's t-test or Fisher's exact test as appropriate using Prism8 Results: 168 patients were included, 126 in the hydroxychloroquine monotherapy arm and 42 in the combination therapy arm Both groups had a similar Tisdale risk score for QT prolongation (7 03 vs 7 24, P = 0 62) There was no difference in incidence of QTc prolongation (34 9% vs 35 7%, P = 1 00) There was no difference in either the average post-treatment QTc (478 17 vs 482 4, P = 0 63) or average change in QTC (34 47 vs 30 31, P = 0 60) No difference was found in incidence of ventricular tachycardia (2 4% vs 4 8%, P = 0 60) There was a higher rate of mortality in patients treated with combination therapy (26 4% vs 45 2%, P = 0 03) Conclusion: Utilization of combination therapy does not result in higher QTc or incidence of ventricular tachycardia when compared to monotherapy The mortality rate was higher for combination therapy Further controlled trials are needed to fully assess this therapy