Abstract: The Effect of Chloroquine, Hydroxychloroquine and Azithromycin on the Corrected QT Interval in Patients with SARS-CoV-2 Infection Running title: Saleh et al.; COVID-19 therapy effect on the QTc Moussa Saleh, MD1,4; James Gabriels, MD1; David Chang, MD1; Beom Soo Kim, MD1; Amtul Mansoor, MD1; Eitezaz Mahmood, MD1; Parth Makker, MD1,4; Haisam Ismail, MD2; Bruce Goldner, MD2; Jonathan Willner, MD1; Stuart Beldner, MD1; Raman Mitra, MD, PHD1; Roy John, MBBS, PHD1; Jason Chinitz, MD3; Nicholas Skipitaris, MD4; Stavros Mountantonakis, MD4; Laurence M. Epstein, MD1 1 Northwell Health, North Shore University Hospital, Department of Cardiology, Division of Electrophysiology, Manhasset; 2Northwell Health, Long Island Jewish Medical Center, Department of Cardiology, Division of Electrophysiology, New Hyde Park; 3Northwell Health, Southside Hospital, Department of Cardiology, Division of Electrophysiology, Bay Shore; 4 Northwell Health, Lenox Hill Hospital, Department of Cardiology, Division of Electrophysiology, New York, NY Correspondence: Moussa Saleh, MD Northwell Health, North Shore University Hospital Department of Cardiology, Division of Electrophysiology 300 Community Drive Manhasset, NY 11030 Tel: (516) 562-4100 Fax: (516) 562-2015 Email: Moussa.a.saleh@gmail.com Journal Subject Terms: Arrhythmias; Sudden Cardiac Death; Treatment; Electrophysiology 1 Abstract: Background - The novel SARs-CoV-2 coronavirus is responsible for the global COVID-19 pandemic. Small studies have shown a potential benefit of chloroquine/hydroxychloroquine ± azithromycin for the treatment of COVID-19. Use of these medications alone, or in combination, can lead to a prolongation of the QT interval, possibly increasing the risk of Torsade de pointes (TdP) and sudden cardiac death. Methods - Hospitalized patients treated with chloroquine/hydroxychloroquine ± azithromycin from March 1st through the 23rd at three hospitals within the Northwell Health system were included in this prospective, observational study. Serial assessments of the QT interval were performed. The primary outcome was QT prolongation resulting in TdP. Secondary outcomes included QT prolongation, the need to prematurely discontinue any of the medications due to QT prolongation and arrhythmogenic death. Results - Two hundred one patients were treated for COVID-19 with chloroquine/hydroxychloroquine. Ten patients (5.0%) received chloroquine, 191 (95.0%) received hydroxychloroquine and 119 (59.2%) also received azithromycin. The primary outcome of TdP was not observed in the entire population. Baseline QTc intervals did not differ between patients treated with chloroquine/hydroxychloroquine (monotherapy group) vs. those treated with combination group (chloroquine/hydroxychloroquine and azithromycin) (440.6 ± 24.9 ms vs. 439.9 ± 24.7 ms, p =0.834). The maximum QTc during treatment was significantly longer in the combination group vs the monotherapy group (470.4 ± 45.0 ms vs. 453.3 ± 37.0 ms, p = 0.004). Seven patients (3.5%) required discontinuation of these medications due to QTc prolongation. No arrhythmogenic deaths were reported. Conclusions - In the largest reported cohort of COVID-19 patients to date treated with chloroquine/hydroxychloroquine ± azithromycin, no instances of TdP or arrhythmogenic death were reported. Although use of these medications resulted in QT prolongation,..