Cardiac troponin T and creatine kinase predict mid-term infarct size and left ventricular function after acute myocardial infarction: a cardiac MR study.

ABSTRACT

PURPOSE: To assess the relation of cardiac troponin T (cTnT) and creatine kinase (CK) release with infarct size and left ventricular function evaluated during the subacute phase as well as four months after acute myocardial infarction (AMI) by contrast-enhanced MRI (CE-MRI). MATERIALS AND METHODS: CMR of 80 patients (68 male, mean age 54.2 ± 11.7 years) was performed within 8 days and 4 months after first acute ST-elevation AMI with successful primary angioplasty. CK and cTnT concentrations were determined serially from admission to day 4 after symptom onset. RESULTS: All single time-points, estimated average release and peak concentrations of CK and cTnT markers correlated significantly with acute and mid-term infarct size (r = 0.43 to 0.79, all P < 0.001), ejection fraction (EF%) (r = -0.42 to -0.58, all P < 0.002) as well as with end-systolic volume (ESV) (r = 0.32 to 0.57, all P < 0.002) at all times of assessment. Patients with cTnT concentrations below the cutoff value of 3.26 µg/L measured 48 h after AMI-related symptom onset had a significant improvement in global (EF P < 0.0001) myocardial function during the study period, whereas in those with cTnT ≥ 3.26 µg/L, functional recovery did not occur (P = 0.09). CONCLUSION: All single, mean and maximum concentrations of cTnT and CK measured within the first 4 days after AMI permit an accurate prediction of infarct size and left ventricular function as determined in the acute phase as well as four months after AMI by CE-MRI.