HUMAN HEART-TYPE CYTOPLASMIC FATTY-ACID-BINDING PROTEIN IN SERUM AND URINE DURING HYPERACUTE MYOCARDIAL-INFARCTION

We have previously reported that serum and/or urinary human heart-type cytoplasmic fatty acid-binding protein (HH-FABP(c)) can be used as an early indicator of myocardial injury (Clin Biochem 1991; 24: 195-201) . To confirm the usefulness of HH-FABP(c) as an early diagnostic indic ator of acute myocardial infarction (AMI), its serum and urinary level s were measured in samples obtained within 6 h after the onset of acut e coronary syndrome related symptoms. Samples were collected from 97 p atients, who were composed of 63 with AMI, 24 with unstable angina and 10 with chest pain syndrome. The positivity of serum and urinary HH-F ABP(c) and cardiac creatine kinase isozyme MB (CK-MB) was analyzed in these samples. Serum HH-FABP(c) levels in AMI were above normal in 91. 4%) (64/70) of the samples tested within 3 h of the onset of symptoms and in 100% (111/111) of those tested at 3-6 h. Elevated urinary HH-FA BP(c) levels in AMI were obtained in 88.9% (8/9) of samples at 0-3 h a nd in 75% (6/8) at 3-6 h. CK-MB activity in AMI was positive in 20% (8 /40) and 66.3% (53/80) of serum samples at 0-3 h and 3-6 h, respective ly. HH-FABP(c) was always positive when a serum sample was positive fo r CK-MB. Serum HH-FABP(c) at 0-6 h in chest pain syndrome and in unsta ble angina were positive in 17.8% (5/28) and 56.7% (34/60), respective ly. The elevated HH-FABP(c) in serum and urine was noted much earlier than that of CK-MB during the hyperacute phase of AMI. HH-FABP(c) show ed high positive value in unstable angina, but it was low in normal co ronary patients having chest pain. However, HH-FABP(c) level in unstab le angina and chest pain syndrome was lower than that of AMI. Thus, HH -FABP(c) may be a valuable indicator for the diagnosis of hyperacute m yocardial infarction.