Blood carnitine as a biomarker for acute myocardial infarction.

Fatty acid oxidation is the major energy providing pathway of the myocardium and its inhibition impairs myocardial function. Earlier studies have demonstrated the malfunction of heart due to myocardial as well as systemic deficiencies of carnitine which plays an essential role in fatty acids metabolism. This study was aimed to compare the blood levels of carnitine between normal subjects and patients with acute myocardial infarction (AMI). A total of 50 AMI male patients (21 STEMI and 29 NSTEMI) and 144 normal controls were recruited. Blood carnitine was analyzed by liquid chromatography-tandem mass spectrometry. Total carnitine levels were significantly higher in STEMI (57.26 ± 4.51μmol/l) and NSTEMI (54.05 ± 3.52μmol/l) patients as compared to control subjects (35.84 ± 1.15 μmol/l). Similar trends were observed for free carnitine levels. The increased levels of carnitine in the blood stream of AMI patients might have resulted due to the poor uptake and/or increased leakage of carnitine through the ischemic myocardium. The clinical implications of these findings for the risk screening or diagnosis/prognosis of AMI require additional follow-up studies