Efficacy of L-Carnitine for Dilated Cardiomyopathy: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND: L-carnitine mediates the utilization of fatty acids and glucose in the myocardium. The potential of L-carnitine in managing dilated cardiomyopathy (DCM) in patients has been extensively reported, with additional benefits. OBJECTIVE: This meta-analysis purposed to explore the clinical efficacy of L-carnitine therapy on DCM patients. METHODS: We searched publications up to May 2020 from several databases including PubMed, Embase, Cochrane Library, Chinese Biomedical (CBM) database, Chinese Science and Technology Periodicals database (VIP), Chinese National Knowledge Infrastructure (CNKI) database, and Wanfang database. Subsequently, publications that met the inclusion criteria were systematically evaluated by two independent reviewers. RESULTS: A total of 23 RCTs conducted in China with 1455 DCM patients were included in this study. In the meta-analysis, L-carnitine therapy was associated with a considerable improvement in the overall efficacy (RR = 1.28, 95% CI (1.21-1.36), P < 0.0001), left ventricular ejection fraction (LVEF) (MD = 6.16%, 95% CI (4.50, 7.83), P < 0.0001), and cardiac output (CO) (MD = 0.88 L/min, 95% CI (0.51, 1.25), P < 0.0001) as compared to the control group. Moreover, L-carnitine therapy significantly decreased left ventricular end-diastolic dimension (LVEDD) (MD = −2.53, 95% CI (-3.95, -1.12), P = 0.0005), brain natriuretic peptide (BNP) (SMD = −1.71 ng/L, 95% CI (-3.02, -0.40), P = 0.01), and the transforming growth factor-beta (TGF-β1) (MD = −56.78 ng/L, 95% CI (-66.02, -47.53), P < 0.0001). CONCLUSIONS: L-carnitine potentially enhanced the therapeutic efficiency in DCM patients. Following weaknesses in the evidence due to low methodological quality and high clinical heterogeneity in the included studies, well-designed trials are recommended.