Relationship between heart-type fatty acid-binding protein levels and coronary artery disease in exercise stress testing: an observational study

Objective: Although, there has been great improvement on the diagnosis and early treatment of acute coronary syndromes, especially in terms of myocardial damage biochemical markers, we do not have a specific marker yet, for using the diagnosis of stable coronary artery disease (CAD). This study aimed to evaluate the relationship between CAD and the changes of heart-type fatty acid binding protein (H-FABP) levels before and after exercise stress testing (EST). Methods: A total of 47 patients were enrolled in this observational study. Of 47 patients, 21 had normal coronary anatomy; the remaining 26 patients had coronary lesions over 70% in at least one major coronary artery. All patients performed EST. Along with this, H-FABP levels before EST and at peak exercise, 1st hour, 3rd hour (3h), were measured in all patients. Differences among the measurements were evaluated through the Friedman test and Wilcoxon test, and the Bonferroni correction was applied to determine which measurement caused the difference. Results: Contrary to expectations, the means of the H-FABP values measured at particular intervals for each group tended to decline from the basal level to the 3h level. When the difference between the 3h measurement and the basal level was compared in each group, the decreasing was statistically significant in both groups (p 0.05). A statistically significant decrease at the 3h measurement compared to the basal level in the CAD group was more apparent than in the control group (2.790±2.569ng/ml vs. 0.837±2.070ng/ml, p=0.009). Conclusion: We found that H-FABP levels did not increase during EST and contrary to expectation, were inclined to decrease. We thought that decreasing H-FABP levels likely resulted from exercise-induced proteinuria.