Abstract: Objective  To investigate the significance of heart-type fatty acid-binding protein (H-FABP） for the early diagnosis of acute myocardial infarction (AMI).  Methods  A total of 144 patients suffered chest pain as the main syndrome were enrolled in the study. The patients were AMI suspected (90 truth cases and 54 suspicion cases). By enzyme-linked immunosorbent assay (ELISA)， serum samples were detected respectively within 3 h and after 6 h of chest pain onset. The H-FABP, cardiac troponin I (cTnI) and creatine kinase isozyme-MB (CK-MB) were detected, and the sensitivity， specificity and diagnostic accuracy in the early diagnosis of AMI were compared. Moreover， 60 healthy subjects with similar age and sex were as the control group. Results  The level of H-FABP［(56.13±19.17) ng/mL］ in AMI group was obviously higher than those in the suspected group ［(11.46±4.85) ng/mL］ and the control group ［(3.14±1.52) ng/mL］within 3 h (P<0.01). Furthermore， its seropositive rate (91.11%)，sensitivity (91.11%)，specificity (98.33%)， diagnostic accuracy (94.67%), positive predictive value (98.80%) and negative predictive value (88.24%) were obviously better than cTnI (13.33%,13.33%,96.67%,48.00%,85.71% and 43.48%) and CK-MB (21.11%,21.11%,95.00%,52.67%,86.36% and 48.80%)(P<0.05，P<0.01). The cTnI and CK-MB levels in AMI group were obviously higher than those in the suspected group and the control group after 6 h (P<0.01). Conclusions  Within 3 h of AMI onset，H-FABP shows good sensitivity，diagnositic accuracy and negative predictive value. H-FABP can be used in the early diagnosis of AMI.

Key words: Heart-type fatty acid-binding protein, Cardiac troponin I, Creatine kinase isozyme-MB, Acute myocardial infarction