Heart-type fatty acid binding protein (hFABP) in the diagnosis of myocardial damage in coronary artery bypass grafting

Objectives: heart-type fatty acid binding protein (hFABP) is an intracellular molecule engaged in the transport of fatty acids through myocardial cytoplasm and has been used as a rapid marl;er of myocardial infarction. However, its value in the evaluation of perioperative myocardial injury has not yet been assessed. Methods: 32 consecutive patients undergoing coronary artery bypass grafting were included in a prospective, randomized study using standardized operative procedures and myocardial protection. Three patients with perioperative myocardial infarction were added. Serial blood samples were taken preoperatively, before ischemia, 5 and 60 min after declamping, 1 and 6 h postoperatively and on postoperative days 1, 2 and 10 and were tested for hFABP, creatin kinase isoenzyme MB (CKMB) and troponin I (TnI). Results: Hospital mortality was zero. The kinetics of the biochemical parameters revealed a typical pattern fur each marker. In routine patients, hFABP levels peaked as early as 1 h after declamping, whereas CKMB and TnI peaked only 1 h after arrival in the intensive care unit. Patients with perioperative infarction displayed peak levels some hours later in all marker proteins. Peak serum levels of hFABP correlated significantly with peak levels of CKMB (r = 0.436, P = 0.011) and TnI(r = 0.5-18, P = 0.001), indicating the degree of myocardial damage. Conclusions: hFABP is a rapid marker of perioperative myocardial damage and peaks earlier than CKMB or TnI. The kinetics of marker proteins in serial samples immediately after reperfusion is more suitable Fur the detection of perioperative myocardial infarction than a fixed cut-off level. (C) 2001 Elsevier Science B.V. All rights reserved.