Role of heart-type fatty acid binding protein in early detection of acute myocardial infarction in comparison with cTnI, CK-MB and myoglobin

Heart fatty acid-binding protein (H-FABP) is supposed to be the most sensitive biomarker of early acute myocardial infarction (AMI). To evaluate the diagnostic value of H-FABP for AMI in the early stage, the plasma levels of H-FABP were measured by sandwich ELISA in 93 patients with suspected AMI at admission within 6 h after onset of chest pain and 69 normal healthy subjects. The plasma concentrations of cardiac troponin-I (cTnI), creatine kinase-MB (CK-MB) and myoglobin (Mb) were assayed at the same time by using corpuscle chemiluminescence for those patients. The patients were classified as AMI group (n = 32) and non-AMI group (n = 61) retrospectively. The diagnostic validity was evaluated in terms of sensitivity, specificity and receiver operating characteristic (ROC) curve analysis. The results showed the cutoff value of H-FABP for AMI was 16.8 ng/ml, and its diagnostic sensitivity for AMI was 64.29% within 3 h and 84.38% within 6 h after onset of chest pain, and the diagnostic specificity for non-AMI was 100% within 3 h and 91.8 % within 6 h. H-FABP had higher sensitivity than that of cTnI and CK-MB at all time points (P<0.05), whereas there was no significant difference in specificity among the four markers. But the area under the ROC curve of H-FABP was significantly greater than that of cTnI, CK-MB and Mb within 3 h. These results revealed that H-FABP possessed high diagnostic sensitivity and specificity for AMI in early stage, especially within 3 h after onset of persistent angina pectoris. In conclusion, H-FABP can be used as a sensitive marker for AMI in the early stage.