Fatty acid-binding proteins (FABPs) are small cytoplasmic proteins that are abundantly expressed in tissues with an active fatty acid metabolism, such as the heart and liver. Nine distinct types of the FABP family have been identified, with Heart-type FABP (H-FABP) being the most widely studied, largely due to the fact that it is found in abundance in the cardiomyocytes.

H-FABP concentrations typically peak at approximately 6-8 hours after symptom of acute coronary syndrome (ACS) and return to normal within 24-30 hours. Although H-FABP has similar release kinetics to Myoglobin (i.e. rapid release & clearance), it is approximately 15-20 times more cardiac specific, hence making it a vastly more efficacious biomarker for myocardial injury. Furthermore, the normal serum/plasma value of H-FABP is much lower than with Myoglobin, which reduces the potential for false positive results.