Glycogen phosphorylase isoenzyme BB in the diagnosis of acute myocardial infarction in early stage

Abstract

Objective To evaluate the value of glycogen phosphorylase isoenzyme BB (GPBB) in the diagnosis of early acute myocardial infarction (AMI). Methods The plasma levels of GPBB were mea-sured by sandwich ELISA in 115 patients with suspected AMI at admission within 6 hours after onset of chest pain and 55 normal healthy subjects. The plasma concent of cardiac troponin-Ⅰ (cTnI), creatine kinase-MB (CK-MB) and myoglobin (MYO) was assayed at the same time by using corpuscle chemiluminescence. The patients were classified retrospectively into AMI group (n = 45) , unstable angina pectoris (UAP) group (n =40) , stable angina pectoris (SAP) group (n = 13) and non-cardiac chest pain (NCCP) group (n =17).The diagnostic validity was evaluated in terms of sensitivity and specificity. Results The diagnostic sensitivity of GPBB for AMI was 64.29 % within 3 hours and 88.89 % within 6 hours after onset of chest pain,which is significantly higher than that of cTnI (28.57 %, 60.00 %) and CK-MB (21.43 %, 64.44 % ). There was no significant difference in specificity among the four markers. The diagnostic accuracy of GPBB within 3hours and 6 hours (80.77 %, 89.57% ) was significantly higher than that of cTnI (61.54%, 81.74% ),CK-MB (50.00%, 75.65%) and MYO (73.08% ,73.91%). Conclusions GPBB seems to be a sensitive and specific biochemical cardiac marker for AMI in the early stage. Its diagnostic accuracy is higher than that of cTnI, CK-MB, MYO. Key words: Myocardial infarction; Early diagnosis; Glycogen phosphorylase, brain form