Effect of Carnitine Supplementation in Pediatric Patients with Left Ventricular Dysfunction.

Carnitine is an essential amino acid involved in transporting fatty acids across the mitochondrial membrane. Fatty acids are a primary source of energy for the myocardium. Studies in adults demonstrated decreased carnitine levels in the ischemic myocardium, but subsequent exogenous carnitine supplementation showed improvement of myocardial metabolism and left ventricular function. However, only limited data regarding carnitine are available in pediatrics. A single-center retrospective, paired data study was conducted. Patients < 18 years, left ventricular ejection fraction (LVEF) < 55% by echocardiography, and had received at least 7 days of oral or intravenous carnitine supplementation between January 2018 and March 2021 are included in the study. Several endpoints and covariates were collected for each patient: before, one week after, one month after, and 6 months after carnitine supplementation. Univariate analysis consisted of an analysis of variance (ANOVA), followed by an analysis of covariance (ANCOVA) to model LVEF while adjusting for other variables. 44 patients included in the final analyses. LVEF significantly improved from 50.5 to 56.6% (p < 0.01). When LVEF was adjusted for other interventions (mechanical ventilation, afterload reduction, diuretic therapy, spironolactone), the estimated means demonstrated a significant increase from 45.7 to 58.0% (p < 0.01). Free carnitine level increased significantly (p = 0.03), and N-terminal-pro-brain natriuretic peptide (p = 0.03), creatinine (p < 0.01), and lactate (p < 0.01) all significantly decreased over the study period. Carnitine supplementation in pediatric patients with left ventricular systolic dysfunction may be associated with an increase in LVEF and improvement in laboratory markers of myocardial stress and cardiac output.