Glycogen phosphorylase isoenzyme BB in the diagnosis of acute myocardial infarction: a meta-analysis

Early diagnosis is crucial for management of patients with suspected acute myocardial infarction (AMI). Among innovative and promising biomarkers, the recent interest raised on glycogen phosphorylase isoenzyme BB (GPBB) has prompted us to perform a meta-analysis of published studies.

A systematic electronic search was carried out on PubMed, Web of Science and Google Scholar, with no date restriction, to retrieve all articles that have investigated the early diagnostic performance of GPBB in patients with suspected AMI, and directly reported or allowed calculation of sensitivity and specificity. A meta-analysis of the reported sensitivity and specificity of each study and pooled area under the curve (AUC) was then performed by random effect approach. Heterogeneity was assessed by I-square statistics.

Eight studies were finally selected for analysis (941 subjects; 506 cases and 435 controls), with a high heterogeneity (I-squared, 86.3%). The resulting pooled estimates and 95% confidence interval were 0.854 (0.801-0.891) for sensitivity, 0.767 (0.713-0.815) for specificity, 0.826 (0.774-0.870) for negative predictive value, 0.802 (0.754-0.844) for positive predictive value, and 0.754 (9.602-0.907) for AUC. In those studies that have simultaneously assessed GPBB and a troponin immunoassay, the combination of these biomarkers did not significantly improve the performance of troponin alone.

GPBB does not meet the current requirements for an efficient diagnosis of AMI when used as a stand-alone test, whereas its combination with troponin merits further investigation in larger trials.