QT interval and arrhythmic safety of hydroxychloroquine monotherapy in coronavirus disease 2019

• Published in: Heart rhythm O2 Vol. 1; no. 3; pp. 167 - 172
• Main Authors: Sridhar, Arun R., Chatterjee, Neal A., Saour, Basil, Nguyen, Dan, Starnes, Elizabeth A., Johnston, Christine, Green, Margaret L., Roth, Gregory A., Poole, Jeanne E.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.08.2020; Elsevier
• Subjects: Clinical; Coronavirus; Electrocardiogram; Hydroxychloroquine; QT interval; Ventricular arrhythmia; Ventricular arrhythmia; QT interval; Coronavirus; Hydroxychloroquine; Electrocardiogram
• ISSN: 2666-5018; 2666-5018
• DOI: 10.1016/j.hroo.2020.06.002

Observational studies have suggested increased arrhythmic and cardiovascular risk with the combination use of hydroxychloroquine (HCQ) and azithromycin in patients with coronavirus disease 2019 (COVID-19). The arrhythmic safety profile of HCQ monotherapy, which remains under investigation as a therapeutic and prophylactic agent in COVID-19, is less established and we sought to evaluate this. In 245 consecutive patients with COVID-19 admitted to the University of Washington hospital system between March 9, 2020, and May 10, 2020, we identified 111 treated with HCQ monotherapy. Patients treated with HCQ underwent a systematic arrhythmia and QT interval surveillance protocol including serial electrocardiograms (ECG) (baseline, following second HCQ dose). The primary endpoint was in-hospital sustained ventricular arrhythmia or arrhythmic cardiac arrest. Secondary endpoints included clinically significant QTc prolongation. A total of 111 patients with COVID-19 underwent treatment with HCQ monotherapy (mean age 62 ± 16 years, 44 women [39%], serum creatinine 0.9 [interquartile range 0.4] mg/dL). There were no instances of sustained ventricular arrythmia or arrhythmic cardiac arrest. In 75 patients with serial ECGs, clinically significant corrected QT (QTc) prolongation was observed in a minority (n = 5 [7%]). In patients with serial ECGs, there was no significant change in the QTc interval in prespecified subgroups of interest, including those with prevalent cardiovascular disease or baseline use of renin-angiotensin-aldosterone axis inhibitors. In the context of a systematic monitoring protocol, HCQ monotherapy in hospitalized COVID-19 patients was not associated with malignant ventricular arrhythmia. A minority of patients demonstrated clinically significant QTc prolongation during HCQ therapy.