Abstract 13069: Baseline QRS Duration ≫ for >140 Msec is Associated with Poor In-Hospital Prognosis of Patients with Acute Myocarditis

Introduction: The clinical manifestation of acute myocarditis (AM) is highly variable, and the mechanisms of this diversity have not been fully elucidated. Hence, it is hard to precisely predict their prognosis, and some cases with AM rapidly progress into cardiogenic shock, resulting in the increased in-hospital mortality. Hypothesis: There are some parameters in the initial presentations to predict the prognosis of patients with AM. Methods: This is a multicenter observational study including hospitalized AM patients between 2007 and 2019. We set the primary endpoint of this study as a composite of in-hospital death from any cause and implantation of ventricular assist devices during the index hospitalization. Results: Of 76 enrolled patients [average age: 42 years; male: 79%; mean left ventricular ejection fraction (LVEF): 41%], 13 patients (17%) developed the composite endpoint, and 8 (11%) died within 10 days after the admission. Patients who experienced the composite endpoint were more likely to be older, and have diabetes, anemia, impaired renal functions, higher creatine kinase-MB, lower LVEF, and longer QRS duration on ECG at admission. In the multivariable logistic regression analysis, QRS duration on ECG at admission was independently associated with the composite endpoint, even after adjusting for confounding factors such as age, sex, and LVEF at admission [OR: 1.31, 95% CI: 1.01-1.72]. The ROC curves for the primary endpoint revealed that the cut-off value of QRS duration at admission were 140 msec (sensitivity: 100%, specificity: 90%, AUC: 0.97). Kaplan-Meier analysis showed that patients with baseline QRS duration > for >140 msec had a significantly higher rate of the primary endpoint than those with QRS duration <140 msec (p<0.001, Figure ). Conclusions: Prolonged QRS duration at admission could predict in-hospital prognosis in patients with AM. We should consider the intensive care and close observation in such a high-risk population with AM.