172 - Risk factors and Outcomes for Children with Myocarditis: The Sickkids Experience

Publication Number: 172.6125

Geena Kim, The Hospital for Sick Children, Sejong, Ch'ungch'ong-namdo, Republic of Korea; Aine Lynch, Columbia University, New York, NY, United States; Jenna Ashkanase, McMaster University Michael G. DeGroote School of Medicine, Hamilton, ON, Canada; Dawn Nicolson, The Hospital for Sick Children, Toronto, ON, Canada; Sunghoon Minn, The Hospital for Sick Children, Toronto, ON, Canada; Aamir Jeewa, The Hospital for Sick Children, MARKHAM, ON, Canada

Background: Myocarditis is an important cause of acute heart failure in children. Despite presentations with hemodynamic compromise, many patients are able to make a full recovery. Identifying risk factors for cardiac death in children with myocarditis can help prognosticate in whom advanced therapies such as mechanical circulatory support is required

Objective: The objective of this study is to compare factors that influence transplant-free survival in children with acute myocarditis

Design/Methods: This retrospective study between Jan 2001 and July 2022 identified all children with acute myocarditis from the Sickkids Heart Failure Database (SKHFD). Presumed Myocarditis was defined as an ejection fraction (EF) of < 50% or qualitatively mildly depressed function and a recent clinical history of viral prodrome/infectious symptoms, elevated biomarkers, typical ECG findings, or diagnostic confirmation by MRI or biopsy. All cases adjudicated by a pediatric cardiologist

Results: A total of 56 patients were included in the study. The median age was 3.5 years (IQR 0-11) with a median weight of 20kg (IQR 5.9 - 34). Neonates accounted for 17% of the cases. Twelve patients (21%) died or were transplanted (ie. non-survivors) in this cohort compared to 44 (79%) survivors. Two echocardiographic parameters differed significantly when comparing survivors to non-survivors: the median left ventricular (LV) EF in the survivors was 40.8±15.2 compared to 20.8±9.7 (p = < 0.001) in the non-survivors, and the LV end-diastolic dimension was smaller in survivors compared to non-survivors (1.61±1.68 vs 3.32±1.94; p = 0.008). This data suggests that non-survivors were more chronic or "burnt-out" in their clinical presentation. No significant findings when comparing biomarkers. On multivariate analysis, the only statistically significant finding was that a higher LVEF was protective from death (HR 0.888 95% CI 0.814-0.968; p = 0.007). The receiver operating characteristic curve of the LVEF at diagnosis showed a cutoff level of 30.5% for predicting death or the need for heart transplantation, with an area under the curve of 0.875, sensitivity of 90.9%, and specificity of 75.6% (P < 0.001) (See Figure 1).

Conclusion(s): This study identified that death or the need for transplant occurs in 1/5 children with acute myocarditis and that a lower LVEF and more dilated LV have been associated with non-survival. These potential risk factors may provide additional data for clinicians around prognostication for severity of disease at the time of presentation. Future directions may include the incorporation of such data in precision health algorithms

The ROC curve of LVEF at diagnosis, predicting death or the need for heart transplantation
Figure 1 LVEF and outcome.pdfThe cutoff value of the left ventricular ejection fraction that predicted death or heart transplant was 30.5% (AUC = 0.875; sensitivity of 90.9%; specificity of 75.6%) (P < 0.001)

The ROC curve of LVEF at diagnosis, predicting death or the need for heart transplantation
Figure 1 LVEF and outcome.pdfThe cutoff value of the left ventricular ejection fraction that predicted death or heart transplant was 30.5% (AUC = 0.875; sensitivity of 90.9%; specificity of 75.6%) (P < 0.001)