Serum free L-carnitine in association with myoglobin as a diagnostic marker of acute myocardial infarction

Abstract

Background Early diagnosis of acute myocardial infarction (AMI) in patients with chest pain is necessary to initiate appropriate treatment. Elevation of ST-segment in ECG is the only marker that cardiologists depend on in diagnosis. The aim of this study was to monitor the level of serum free L-carnitine in combination with myoglobin (Myo) and creatine kinase (total activity and CK-MB level) for usefulness as a predictor of AMI in ICU patients. Design and methods In the present study serum total CK activity and CK-MB, Myo, and free L-carnitine levels were determined in 90 patients admitted to the ICU at Ain Shams University Hospital and correlated the sensitivity and specificity of each parameter. Results Obtained data revealed that, 47/90 who were diagnosed as AMI showed a highly significant reduction in serum free L-carnitine level in all cases as compared to normal control ( P < 0.001), 24/90 diagnosed as unstable angina showed a non significant reduction of serum carnitine and 19/90 who were diagnosed as noncardiac showed non significant changes in the level of serum free carnitine as compared to normal control. In addition, serum free L-carnitine level was negatively correlated to CK-MB and Myo ( r = − 0.61 and − 0.52) respectively. The sensitivity of carnitine assay was considerably higher (95.5%) compared to CK-MB (87%) and Myo (89.5%) even considering patients with a short delay until admission. Conclusion Comparing the changes in serum total CK, levels of CK-MB, Myo and carnitine, the sensitivity and specificity were significantly higher for serum free L-carnitine. For this reason, serum free L-carnitine can be used as a good predictor for AMI diagnosis from other diseases.