Heart Rhythm O2 (Aug 2020)

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

  • Arun R. Sridhar, MBBS, MPH,
  • Neal A. Chatterjee, MD, MSc,
  • Basil Saour, MD,
  • Dan Nguyen, MD,
  • Elizabeth A. Starnes, ARNP,
  • Christine Johnston, MD, MPH,
  • Margaret L. Green, MD, MPH,
  • Gregory A. Roth, MD,
  • Jeanne E. Poole, MD, FHRS

Journal volume & issue
Vol. 1, no. 3
pp. 167 – 172

Abstract

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Background: 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). Objective: 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. Methods: 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. Results: 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. Conclusions: 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.

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