POS1240 HYDROXYCHLOROQUINE CARDIOTOXICITY: A CASE-CONTROL STUDY COMPARING PATIENTS WITH COVID19 AND PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS

Background: Antimalarials have been associated with QT prolongation in COVID19 patients but are generally safe in patients with rheumatologic disease. Objectives: Aim of the study was to compare the prevalence of QTc prolongation between COVID19 and Systemic Lupus Erythematosus (SLE) patients treated with hydroxychloroquine (HCQ). Methods: We included consecutive patients with SARS-CoV-2 infection confirmed by nasopharyngeal swab and patients taking HCQ for SLE. A prolonged QTc was defined as an increase in QTc intervals >60 ms (compared with baseline) or as a QTc of ≥500 ms. Results: We enrolled 58 COVID19 patients (median age 70.5 years, IQR 25). HCQ, without or with azithromycin, was given to 26 (44.8%) and 15 patients (25.9%), respectively; 17 (29.3%) had not received either drug. The median baseline QTc was 432 (IQR 36) and prolonged QTc was observed in 15 (26%) patients (12 QTc≥500 ms and 3 patients ΔQTc>60 ms). We didn’t find significant differences in QTc prolongation among the three treatment groups. Baseline QTc (OR 111.5) and D-dimer (OR 78.3) were independently associated to QTc prolongation. Compared to the 50 SLE patients (median age of 38.5 years, IQR 22), chronically treated with HCQ, patients with COVID19 showed significantly longer QTc (p Conclusion: This is the first study demonstrating that, differently from COVID19 patients, patients with SLE are not susceptible to HCQ-induced long QT syndrome and arrhythmia. The combined arrhythmogenic effect of SARS-CoV-2 infection and HCQ could account for the excess of QTc prolongation and fatal arrhythmias described in patients with COVID19. Disclosure of Interests: None declared