Plasma and Urinary Levels of Heart Fatty Acid-Binding Protein in Patients Undergoing Cardiac Surgery

Abstract

To evaluate the clinical significance of the plasma and urinary levels of heart fatty acid-binding protein (H-FABP) in patients undergoing cardiac surgery, a prospective study was conducted. Ten patients undergoing coronary artery bypass grafting were enrolled. Blood samples for determination of plasma H-FABP (pH-FABP), the MB isoenzyme of creatine kinase (CK-MB) and troponin-T (TnT), and urine samples for determination of urinary H-FABP (uH-FABP) were collected serially. None of the patients had perioperative myocardial infarction. The time to reach the peak level after aortic declamping was significantly (P<0.05) shorter for pH-FABP (1.4±0.5h) than for CK-MB (2.5±0.5h), TnT (6.6±1.3h) or uH-FABP (3.0±0.6h). Peak levels of pH-FABP correlated with those of CK-MB (r=0.51, p=0.04), TnT (r=0.60, p=0.03) and uH-FABP (r=0.61, p=0.03), and peak levels of uH-FABP correlated with CK-MB (r=0.57, p=0.04). Postoperative uH-FABP levels correlated inversely with the left ventricular stroke work index (r=-0.63, p=0.04). This study demonstrated that H-FABP appears rapidly in plasma after reperfusion and reaches its peak earlier than other available biochemical markers; it appears also in urine and the levels correlated with cardiac function. Plasma and urinary H-FABP may be an early and sensitive biochemical marker for the diagnosis of myocardial injury in patients undergoing cardiac surgery.