PM1034: Effect of Carnitine Supplementation in Pediatric Patients with Left Ventricular Dysfunction

Background: Carnitine is an essential amino acid involved in transporting fatty acids across the mitochondrial membrane. Fatty acids serve as a primary source of energy for the myocardium. Previous studies in adults have demonstrated decreased carnitine levels in the myocardium during periods of ischemia. Subsequent exogenous carnitine supplementation was then demonstrated to improve myocardial metabolism as well as left ventricular function in adults. However, in the pediatric population, there is limited data regarding carnitine. A retrospective review of carnitine supplementation in pediatric patients was performed to assess change in left ventricular function.

Methods: A single-center retrospective, paired data study was conducted. Patients included in this study were under 18 years of age, had a left ventricular ejection fraction of less than 55% by echocardiography and had received at least 7 days of oral or intravenous carnitine supplementation. Data was obtained between January 2018 and March 2021. Several endpoints as well as covariates were collected for each patient before, one week after, one month after, and six months after carnitine supplementation. Univariate analysis consisted of an ANOVA which was then followed by an ANCOVA to model left ventricular ejection fraction while adjusting for other variables.

Results: There were 44 patients included in the final analyses. Mean age at the time of carnitine initiation was 28 months, mean weight at first dose was 14.6 kg, and mean daily dose of carnitine on initiation was 65.4 mg/kg/day. Left ventricular ejection fraction significantly improved over the study period, increasing from 50.5% to 56.6% (p < 0.01). When ejection fraction 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). From laboratory marker standpoint, 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.

Conclusion: Carnitine supplementation in pediatric patients with left ventricular systolic dysfunction may be associated with an increase in left ventricular ejection fraction and improvement in laboratory markers of myocardial stress and cardiac output.