Prospective QTc interval monitoring avoids cardiac toxicity of hydroxychloroquine and azithromycin in critically ill SARS-CoV-2 patients: a cohort study

Purpose: During the first wave of the SARS-Cov2 pandemic, the use of hydroxychloroquine and azithromycin raised safety concerns in terms of arrhythmias related to QT segment prolongation. The aim of this observational, prospective, single-center study was to describe cardiovascular events in critically ill patients who were mechanically ventilated for SARS-Cov2 pneumonia. Methods Patients included were prospectively monitored for QTc segment prolongation when treated with the association of hydroxychloroquine alone or in combination with azithromycin for Covid-19 pneumonia and treatment had to be stopped before QTc ≤ 500ms. Results 23 patients were prospectively included. Treatment had to be interrupted in 43.5% of patients and more often in the combination group. None of the patients displayed torsade de pointes or sudden cardiac arrest. Forty percent of patients in the combination group experienced atrial fibrillation. Cardiac Troponin I was elevated in 70% of all patients without electric signs of ischemia. Conclusion The association of hydroxychloroquine and azithromycin for treatment of Covid-19 pneumonia mandates the need for prospective evaluation of QTc especially in the presence of biological myocardial injury. The Institutional Review Board waived the need for consent to use prospectively collected clinical data and the study was appointed the serial number 2020-214.