Contemporary Care and Outcomes of Critically Ill Children with Myocarditis

Abstract

<h3>Purpose</h3> To describe contemporary management and outcomes in children with myocarditis admitted to the cardiac intensive care unit (ICU) and to identify characteristics associated with mortality. <h3>Methods</h3> All patients diagnosed with myocarditis by the treating clinician in the Pediatric Cardiac Critical Care Consortium (PC4) registry from 8/2014-6/2020 were included. Descriptive statistics summarized cohort characteristics and outcomes. Univariable analyses and multivariable logistic regression evaluated factors associated with in-hospital mortality. <h3>Results</h3> There were 847 ICU admissions for myocarditis in 51 centers. Median age was 12y (IQR 2.7-16). In-hospital mortality occurred in 53 patients (6.3%), 60 (7.1%) had cardiac arrest, and 17 (2%) underwent heart transplant during the admission. Mechanical ventilation was required in 339 patients (40%) and MCS in 177 (21%): ECMO-only in 142 (16.7%), ECMO-to-VAD in 20 (2.4%), E-CPR in 43 (5%), VAD-only in 15 (1.8%) patients. MCS was associated with in-hospital mortality; 20.3% receiving MCS died compared to 2.5% without MCS (p<0.001). Mortality was not different between ECMO-only, ECMO-to-VAD, and VAD-only groups. Median time from ICU admission to ECMO was 2.0hr (IQR 0-9.4) and to VAD was 9.9d (IQR 6.3-16.8). Time to MCS was not associated with mortality. Patient characteristics associated with unadjusted in-hospital mortality were younger age, smaller BSA, higher serum lactate, higher BNP, and lower eGFR on ICU admission (Table). In multivariable modeling, smaller BSA and low eGFR remained associated with mortality. <h3>Conclusion</h3> This contemporary cohort of critically ill children with myocarditis frequently required high-resource therapies such as mechanical ventilation and ECMO. However, the vast majority of patients survived to hospital discharge and rarely received VAD and/or heart transplant. Smaller patient size and renal dysfunction were independently associated with mortality.