The Value Of Heart-Type Fatty Acid-binding Protein For Early Detection Of Acute Myocardial Infarction

Background:Acute myocardial infarction(AMI) is a common cardiovascular disease. It has highly morbidity and fatality. The most updated recommendations for AMI diagnosis suggested that biomarkers of myocardial infarction are the bases of the diagnosis and other information such as history,electrocardiogram,and coronary angiography should also be taken into account. Cardiac troponin (cTn) and creatine kinase MB(CK-MB) are specific markers for myocardial damage. Their elevations can be tested in blood only after 4~6 hours of AMI. On the contrary,myoglobin has an earlier increase compared to cTn but with a low specificity for myocardial infarction. Though it can be tested in blood after 2~3 hour of AMI, it can't distinguish skeletal muscle from myocardial muscle damage. So a new biomarker for AMI is needed to make an early definite diagnosis of AMI. Heart-type fatty acid binding protein (H-FABP )is a low molecular weight plasmosin with a high degree of specificity. It is released into plasma in significant amount within 2 hours, so it can be to reach significance level for AMI.Object:To test if the qualitative assay of H-FABP can be used for the diagnosis of acute myocardial infarction in the early stage. Moreover,to compare the diagnostic efficacy of cTnI with H-FABP in early diagnosis of AMI.Methods:Fifty-six patients who are suspected with AMI are selected in this study (including 27AMI by final diagnosis).Venous blood samples were taken three times at three points of within-4 hours , within-6 hours and beyond- 6hours of chest pain onset. According to solid phase immuno-chromatographic theory,we tested the H-FABP by using quick reactant board. cTnI were quantitatively measured at the same time.Result:There are no significant difference in positive rate of H-FABP and cTnI in three time points in non-AMI group(P >0.05).No significant difference in positive rate of H-FABP in three points in AMI group(P >0.05), but the cTnI of within-6 hours positive rate was significantly higher than that of within-4 hours positive rate in AMI patients(P<0.05), and beyond-6 hours was the highest(P<0.05).The sensitivity accuracy and the negative predictive value of H-FABP were superior to cTnI within-6 hours and within-4 hours of the chest onset. But the difference of these parameters between H-FABP and cTnI disappeared after 6 hours of chest pain onset. In terms of diagnostic efficacy,H- FABP are superior to cTnI within 4 hours and within 6 hours of symptom onset(P<0.005,P<0.005),while no difference was found after 6 hours of symptom onset(P>0.5).Conclusion:As a new myocardiolysis marker,H-FABP has a higher sensitivity,specificity,positive and negative predictive value. Within 6 hours of onset of AMI,the H-FABP has a better diagnostic efficacy than cTnI. The H-FABP can be used in the early diagnosis of AMI. However,it is unclear whether the H-FABP has a diagnostic value in patients with unstable angina (UA). Further study is needed for its role in evaluating the prognosis of UA.