Abstract
Background: The measurement of myocardial infarct size is important to predict a patient s prognosis and to evaluate the effectiveness of therapeutic interventions. The aim of this study was to summarize published evidence regarding estimation of myocardial infarct size by cardiac troponin T (cTnT), cardiac troponin I (cTnI) and creatine kinase-MB (CK-MB).
Methods: Pubmed and Cochrane were searched for articles/reviews validating estimation of myocardial infarct size by cTnT, cTnI or CK-MB.
Results: Peak value and area-under-curve (auc) for cTnT and CK-MB correlate closely with scintigraphic and pathoanatomical infarct size, but the evidence are limited. Only one study evaluates cTnI auc versus scintigraphic infarct size, which correlate moderately. Furthermore the sample size is small. Single-measurements of cTnT at 72 hours after infarction correlate closely with scintigraphic infarct size in one study.
Conclusions: cTnT and cTnI are today the preferred biomarkers for myocardial damage with high sensitivity and nearly absolute myocardial tissue specificity. CK-MB mass is less specific, but nevertheless a good marker for cardiac damage. Evidence validating cTnI for estimation of infarct size are extremely limited. The data documenting CK-MB and cTnT are somewhat stronger. As cTnT is more specific than CK-MB, cTnT auc or peak should be preferred for biochemical estimation of infarct size. Regarding single-samples further studies are needed, but initial data for cTnT at 72 hours after infarction are promising.