Predicting microvascular obstruction with cardiac troponin T after acute myocardial infarction: a correlative study with contrast-enhanced magnetic resonance imaging.

BACKGROUND: The presence of microvascular obstruction (MVO) is associated with more severely impaired left ventricular function and adverse prognosis. The aim of this study was to evaluate whether a single cardiac troponin T-value (cTnT) was able to predict the presence of MVO and whether cTnT is an independent predictor of MVO as compared to usual risk factors. STUDY DESIGN AND METHODS: Sixty-one consecutive patients with reperfused ST-elevation myocardial infarction (STEMI) were enrolled in the study. cTnT was measured serially at admission and after 24, 48, 72 and 96 h. Contrast-enhanced cardiac magnetic resonance imaging (CE-MRI) was performed on a 1.5T MR-scanner 4 +/- 1 days after STEMI.
RESULTS: cTnT-time concentration kinetics in the presence of MVO differs from cTnT release in the absence of MVO showing a higher peak and a slower release. At single point measurement 24 h-cTnT correlates at least as well with the presence of MVO (P < 0.001) as peak cTnT (P = 0.0016) and sampling over 96 h (P < 0.001). Using ROC analysis, at single measurement a cTnT concentration >2.52 microg/l at 24 h was a predictor for MVO (AUC 0.91) with a sensitivity of 100% and a specificity of 80% with a positive predictive value of 76% and a negative predictive value of 100%. In multivariate regression analysis 24 h-cTnT remained independent predictor for MVO.
CONCLUSIONS: In STEMI, a single 24 h-cTnT value is an independent predictor for MVO and a convenient and inexpensive way to help define this important risk parameter in clinically routine.