Impact of ventricular arrhythmias on outcomes in children with myocarditis.

Children affected with acute myocarditis may progress rapidly into profound ventricular dysfunction and ventricular arrhythmias. The objective of this study is to assess the impact of ventricular arrhythmias on in-hospital mortality and the use of mechanical circulatory support in patients with myocarditis. Pediatric patients (age 0-18 years) admitted with myocarditis were identified from the National Inpatient Sample dataset for the years 2002-2015. A total of 12,489 patients with myocarditis were identified. Of them, 1627 patients were with ventricular arrhythmias and 10,862 patients without ventricular arrhythmias. Mortality was higher in those with ventricular arrhythmias (19.5% vs. 2.8%, OR = 8.47; 95% CI 7.16-10.04; p < 0.001). The median length of stay and the median cost of hospitalization were higher in the ventricular arrhythmias group (9 days vs. 4 days, p < 0.001 and $121,826 vs. $37,658, p < 0.001, respectively). There was a substantial increase in the utilization of extracorporeal membrane oxygenation (ECMO) in patients with ventricular arrhythmias (25.4% vs. 2.7%, OR = 12.40; 95% CI 10.55-14.57; p < 0.001). The use of ventricular assist devices (VADs) was higher in patients with ventricular arrhythmias (4.5% vs. 1.3%, OR = 3.76; 95% CI 2.82-5.01; p < 0.001). An improvement in discharge survival was observed over the years of study in both VA and non-VA groups; associated with this decline in mortality, there was a rising trend of ECMO utilization.Conclusion: Development of ventricular arrhythmia in children with myocarditis is a strong predictor for mortality and ECMO utilization. What is Known: • The clinical presentation of pediatric myocarditis varies from no symptoms of myocardial dysfunction to a rapidly progressing severe congestive heart failure. • Little is known about the predictors of mortality in children with suspected myocarditis. What is New: • Development of ventricular arrhythmia in children with myocarditis is a strong predictor for mortality and ECMO utilization. • Improvement in discharge survival was observed over the years of study; associated with this decline in mortality, there was a rising trend of ECMO utilization.