COVID-19 and QTc: Is Hydroxychloroquine worth the risk?

Title: COVID-19 and QTc: Is Hydroxychloroquine worth the risk?
Author(s): A Pollock C Gill R Kumar P Devitt C Daly BD Kent
Institution: St James' Hospital
Poster: Click to view poster
Category: COVID-19
Abstract: Hydroxychloroquine (HCQ) and Azithromycin (AZ) have been used in the treatment of coronavirus disease 2019 (COVID-19). Both are associated with QT prolongation, which can precede malignant arrhythmias. We assessed the incidence of QT prolongation secondary to HCQ and AZ, and associated morbidity and mortality.

A review was performed of COVID-19 patients treated with HCQ +/- AZ, in our hospital in March and April 2020. Baseline and change in corrected QT interval (QTc) were calculated using Bazett’s formula.

Out of 62 PCR confirmed COVID-19 patients, 58 patients (93.5%) received both HCQ and AZ, while 4 patients (6.5%) received HCQ alone. Significant QT prolongation (increase in QTc ≥60msec or QT peak ≥500msec) was seen in 24.2% of patients. Patients with QT prolongation had a significantly higher risk of death (33% vs 4.3%; p=0.03), increased likelihood of ICU admission (20.5% vs 8.7%), and increased length of stay (24.7 vs 18.6 days).

In this study, patients who were treated with HCQ+/-AZ were at high risk of QT prolongation. This was associated with increased incidence of death, ICU admissions and length of stay. Close cardiac monitoring and rationalisation of additional QT prolonging drugs are essential to prevent adverse cardiac events.