Frequency of Long QT in Patients with SARS-CoV-2 Infection Treated with Hydroxychloroquine: A Meta-analysis

Introduction Hydroxychloroquine (HCQ) has been proposed as a SARS-CoV-2 treatment but the frequency of long QT (LQT) during use is unknown. Objective To conduct a meta-analysis of the frequency of LQT in patients with SARS-CoV-2 infection treated with HCQ. Data Sources PubMed, EMBASE, Google Scholar, the Cochrane Database of Systematic Reviews and preprint servers (medRxiv, Research Square) were searched for studies published between December 2019 and June 30, 2020. Methods Effect statistics were pooled using random effects. The quality of observational studies and randomized controlled trials was appraised with STROBE and the Cochrane Risk of Bias Assessment tools, respectively. Outcomes Critical LQT was defined as: (1) maximum QT corrected (QTc)≥500 ms (if QRS<120 ms) or QTc≥550 ms (if QRS≥120 ms), and (2) QTc increase ≥60 ms. Results In the 28 studies included (n=9124), the frequency of LQT during HCQ treatment was 6.7% (95% confidence interval [CI]: 3.7-10.2). In 20 studies (n=7825), patients were also taking other QT-prolonging drugs. The frequency of LQT in the other 8 studies (n=1299) was 1.7% (95% CI: 0.3-3.9). Twenty studies (n=6869) reported HCQ discontinuation due to LQT, with a frequency of 3.7% (95% CI: 1.5-6.6). The frequency of ventricular arrhythmias during HCQ treatment was 1.68% (127/7539) and that of arrhythmogenic death was 0.69% (39/5648). Torsades de Pointes occurred in 0.06% (3/5066). Patients aged >60 years were at highest risk of HCQ-associated LQT (P<0.001). Conclusions HCQ-associated cardiotoxicity in SARS-CoV-2 patients is uncommon but requires ECG monitoring, particularly in those aged >60 years and/or taking other QT-prolonging drugs.