Objective To evaluate the relationship between the change of Heart-fatty acid-binding protein and myocardial injury/infarction in postoperative of off-pump coronary artery bypass grafting (OPCAB).Methods 59 patients (male 37 and female 22,from 46 to 83 years old) who were the first time to undergoing OPCAB were included in this study.Serial venous blood samples were taken at after induction of anesthesia,the OPCAB finished (after the last anastomosis),entered ICU,2,4 and 8 hours after the patient entered ICU,and at 1 and 2 day postoperative to test H-FABP.The cTnI and CK-MB were tested at 4 and 8 hours,after entering ICU,and at 1 and 2 days postoperative.Patients were divided into 3 groups by the changes of ECG and the level of cTnl at 8 hours after they entered ICU:normal group (group I,cTnI ＜0.1 ng/ml),myocardial injury group(group Ⅱ,cTnI 0.l-1.0 ng/ml) and.myocardial infarction group(group Ⅲ,cTnI ＞ 1.0 ng/ml).Results The level of H-FABP released was significantly higher in the myocardial infarction group than normal group and myocardial injury group (P ＜ 0.01).There is good correlation between the H-FABP and cTnI or CK-MB.But the peak level of H-FABP is earlier (finished OPCAB) (P ＜ 0.05),and it peaked early at 2h after entered ICU (P ＜ 0.01),it began to decrease at 4 hours after entered ICU and returned to baseline at 1 day postoperative,while the cTnI and CK-MB peaked at postoperative day 1 and 8h after entered ICU respectively,and maintained in higher level at postoperative 2 days.Conclusion There is good correlation between the H-FABP and perioperative myocardial infarction in OPCAB,and it has superiority compared with cTnI,which is as gold standard for perioperative myocardial infarction,on a certain degree.It can benefit from early detection of H-FABP for myocardial infarction in perioperative of OPCAB.