Elsevier

International Journal of Cardiology

Volume 324, 1 February 2021, Pages 242-248
International Journal of Cardiology

Assessing QT interval in COVID-19 patients:safety of hydroxychloroquine-azithromycin combination regimen

https://doi.org/10.1016/j.ijcard.2020.09.038Get rights and content

Highlights

  • Only the use of HCQ in combination with AZT causes a significant increase of QT interval.

  • Older patients are at higher risk of prolonged QT when treated with HCQ with/without AZT.

  • The use of HCQ alone or in combination with AZT might be considered as safe relating to arrhythmic risk in the treatment of COVID-19 patients.

Abstract

Background

Hydroxychloroquine (HCQ) and azithromycin (AZT) have been proposed for COVID-19 treatment. Data available in the literature reported a potential increased risk of fatal arrhythmias under these therapies. The aim of this study was to assess the effects of these drugs on QT interval and outcome in a COVID-19 population.

Method

A total of 112 consecutive COVID-19 patients were included in this analysis and were divided in 3 groups according to the receiving therapeutic regimens: 19 (17%) patients in Group 1 (no treatment), 40 (36%) in Group 2 (HCQ only), 53 (47%) in Group 3 (HCQ/AZT).

Results

A prolonged QTc interval was found in 61% of patients treated with HCQ alone or in combination with AZT, but only 4 (4%) patients showed a QTc > 500 ms. HCQ/AZT combination determined a greater increase of QTc duration compared to the other two strategies (Group 3 452 ± 26.4 vs Group 2 436.3 ± 28.4 vs Group 1 424.4 ± 24.3 ms, respectively; p < 0.001). Multivariate analysis demonstrated that HCQ/AZT combination (OR 9.02, p = 0.001) and older age (OR 1.04, p = 0.031) were independent predictors of QTc prolongation. The risk increased with age (incremental utility analysis p = 0.02). Twenty patients (18%) died, and no cardiac arrest neither arrhythmic fatalities were documented.

Conclusions

The HCQ/AZT combination therapy causes a significantly increase of QT interval compared to HCQ alone. Older patients under such regimen are at higher risk of experiencing QT prolongation. The use of such drugs may be considered as safe relating to arrhythmic risk in the treatment of COVID-19 patients as no arrhythmic fatalities occurred.

Keywords

COVID-19
QT interval
ECG
Hydroxychloroquine
Azithromycin
Age

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1

These authors contributed equally to this work.

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