Abstract 16140: Utility of Cardiovascular Magnetic Resonance Imaging in Clinical Decision Making for Children and Adolescents With Hypertrophic Cardiomyopathy

Abstract

Introduction: Cardiovascular magnetic resonance (CMR) imaging is recommended for surveillance and risk stratification in patients with hypertrophic cardiomyopathy (HCM), but the role of CMR findings in clinical decision making has not been described in a pediatric population. Methods: In this single center retrospective study we identified all patients with HCM who underwent CMR. We then determined if there was a clinical management change based on CMR findings. Results: We identified 136 patients with an HCM diagnosis from 2005-2022. Of these, 55 patients (40%) underwent 76 CMR studies. The HCM etiology was genetic or familial in 31 (56%), idiopathic in 21 (38%), and syndromic in 3 (5%); 34% of patients were female; and the median age (and IQR) of included patients at first CMR was 12 (9-15) years old. Ten patients underwent more than one CMR. Both awake and sedated CMRs were included and there were no complications. Management changes included confirmation of HCM diagnosis in 9 patients (16%), change in medical therapy for 3 (5%), myectomy recommendation in 1 (2%), and implantable cardioverter defibrillator (ICD) placement recommendation in 11 (20%). Of those recommended for ICD placement, 8 were a result of new late gadolinium enhancement and 3 had massive septal hypertrophy (median Z-score 30) discovered or confirmed by CMR. To date, no ICDs have discharged any shocks. Altogether, changes in clinical management were made based on CMR findings for 22 patients (40%), representing a change in management as a result of 29% of the total CMRs performed. Conclusion: CMR is an important contributor to clinical decision making in the management of children and adolescents with HCM. Specifically, CMR in this population was especially useful in defining the diagnosis of HCM in the presence of an equivocal echocardiogram and deciding to place an ICD. Fewer CMRs contributed to decision making regarding medical therapy and septal myectomy.