Relative role of NT-pro BNP and cardiac troponin T at 96 hours for estimation of infarct size and left ventricular function after acute myocardial infarction

Background: N-terminal brain-type natriuretic peptide (NT-pro BNP) and cardiac troponin T (cTnT) after acute myocardial infarction (AMI) have proven useful for prediction of prognosis and may be valuable for assessment of left ventricular function and infarct size. The aim of the present study was to correlate infarct size and left ventricular function determined by cine and late gadolinium enhanced CMR with plasma levels of TNT and NT-pro BNP levels after AMI. Methods: We studied 44 patients (pts) with first ST- and non-ST-segment elevation myocardial infarction (STEMI = 23 pts.,NSTEMI = 21 pts.). We measured NT-pro BNP and cTnT on a single occasion at 96 hours after onset of symptoms. Results: There was a moderate inverse correlation between NT-pro BNP and LV-EF in STEMI (r = -0.67, p = 0.0009) and NSTEMI (r = -0.85, p < 0.0001). Likewise, cTnT showed a significant inverse correlation with LV-EF in STEMI (r = -0.54, p = 0.014) but not in NSTEMI. With cTnT there was a strong linear correlation with infarct mass and relative infarct size in STEMI (r = 0.92, p < 0.0001) and NSTEMI (r = 0.59, p < 0.0093). NT-pro BNP demonstrated a good relationship with infarct mass (r = 0.79, p < 0.0001) and relative infarct size (r = 0.755 p < 0.0001) in STEMI, but not in NSTEMI. Conclusion: A single NT-pro BNP and cTnT value at 96 hours after onset of symptoms proved useful for estimation of LV-EF and infarct size. In direct comparison, NT-pro BNP disclosed a better performance for estimation of LV-EF whereas cTnT was superior for assessment of infarct mass and relative infarct size, suggesting an implementation of a dual marker strategy for diagnostic and prognostic work-up.