Impaired Myocardial Work in Children with Hypertrophic Cardiomyopathy and Left Ventricular Fibrosis on Cardiac Magnetic Resonance Imaging.

Echocardiography is pivotal for diagnosis and monitoring of hypertrophic cardiomyopathy (HCM) and can evaluate myocardial function using myocardial work (MW) calculations. Echocardiography is often supplemented by cardiovascular magnetic resonance (CMR) imaging, which can detect myocardial fibrosis using late gadolinium enhancement (LGE). We sought to study the relationship between baseline LGE and MW at baseline and during follow-up in pediatric HCM patients. During the study period (2008-2023), 75 patients were followed up for HCM. In 14 patients (age 14.2 ± 2.8 years, 50.0% male, 6.4 ± 2.9 years follow-up), both LGE-CMR and echocardiography were performed. Global work index (GWI), global constructive work (GCW), global wasted work, and global work efficiency (GWE) were measured, and myocardial fibrosis was estimated by qualitative assessment of LGE. Patients with LGE (n = 7) exhibited significantly impaired baseline MW, including GWI (mean difference, MD - 487.4 mmHg %, 95% CI [- 866.8 mmHg % to - 108.3 mmHg %], p = 0.027), GCW (MD - 536.8 mmHg %, 95% CI [- 929.8 mmHg % to - 144.4 mmHg %], p = 0.020), and GWE (MD - 4.4%, 95% CI [- 8.1% to - 0.7%], p = 0.039). Regional analysis revealed impaired MW indices in segments with LGE, notably basal and mid septal segments. GWI demonstrated high diagnostic performance for LGE presence (sensitivity 93%, specificity 88%, and area under receiver operating characteristic curve 0.85). Baseline LGE presence had no significant impact on MW deterioration during follow-up. MW is significantly impaired in HCM patients with myocardial fibrosis, highlighting potential utility of echocardiography-derived MW analysis as a valuable tool.