Abstract 16107: Electrocardiographic Findings and Their Associations With Adverse Outcomes in Hospitalized Patients With COVID-19

Introduction: Although primarily a respiratory illness, COVID-19 frequently involves the cardiovascular system. Hypothesis: Accordingly, we assessed whether abnormal electrocardiographic findings, including cardiac dysrhythmias, ST/T wave changes, and QTc interval prolongation, predict adverse outcomes in patients with COVID-19. Methods: A multi-center retrospective study of hospitalized patients with COVID-19 was performed across 4 hospitals in Texas and 1 in New York. Initial and subsequent ECG findings among patients with uncomplicated disease course, patients with adverse clinical outcomes (need for vasopressors, mechanical ventilation or renal replacement therapy) and patients who died were analyzed. Univariable and multivariable Cox analyses were performed. Results: We identified 297 consecutive patients with COVID-19. Of these patients, 91% had available ECGs. Median heart rate on initial ECG was 92 bpm (IQR: 27), and median QTc interval was 442 msec (IQR: 40). Longer QTc interval on initial ECG was associated with adverse clinical outcomes (443 msec, IQR: 43) and death (457 msec, IQR: 52, vs 441.5 msec, IQR: 36; p=0.033). Cardiac dysrhythmias or ST/T wave changes were noted in subsequent ECGs of 46% of patients and were associated with adverse clinical outcomes (58%) or death (68% vs 33%; HR: 2.2, 95% CI: 1.3-3.6; p=0.002). Sixty-four patients (23%) developed a QTc interval >500msec during their hospitalization. In multivariable Cox analysis, history of coronary artery disease was independently associated with development of QTc>500msec (HR 2.1, 95% CI 1.0-4.4; p=0.047) while other baseline comorbidities were not. Patients with QTc>500msec were more commonly treated with azithromycin (91% vs 77%; p=0.048); no other differences in COVID-19 treatment were identified. In-hospital mortality among patients with QTc>500msec was 37% versus 13% among patients with shorter QTc intervals (HR: 2.6, 95% CI 1.5-4.5; p=0.001). Conclusions: Prolonged QTc interval on initial ECG of COVID-19 patients predicted adverse outcomes and death. Azithromycin was associated with development of QTc>500msec. Patients with a QTc interval >500msec had a 2.6 times higher risk for in-hospital mortality compared to patients with shorter QTc intervals.