Peak Cardiac Troponin-T Level, Scintigraphic Myocardial Infarct Size and One-Year Prognosis in Patients Undergoing Primary Percutaneous Coronary Intervention for Acute Myocardial Infarction

Current guidelines recommend troponin T (TnT) as the biomarker of choice in the diagnosis of myocardial infarction In patients with ST-elevation myocardial infarction (STEMI) however, its role in providing a measurement of infarct size and its association with survival is less well established We sought to assess the correlation of TnT and creatine kinase-MB (CK-MB) with scintigraphically determined infarct size and to assess the predictive value of all 3 parameters on 12-month mortality Patients presenting with STEMI managed with primary percutaneous intervention underwent serial TnT and CK-MB measurements at admission and for >= 72 hours after presentation Before hospital discharge patients underwent assessment of infarct size by technetium-99m sestamibi single-photon emission computed tomographic (SPECT) scan Clinical follow-up was performed up to 1 year Data were available for 1,237 patients Mean age was 62 9 12 9 years Infarct location was anterior in 509 patients (41%), 75 (6 1%) had cardiogenic shock Median admission and peak TnT were 0 74 mu g/L (0 10 to 2 70) and 3 70 mu g/L (1 69 to 6 99), respectively Corresponding values for CK-MB were 44 1 U/L (21 0 to 108 8) and 160 0 U/L (69 0 to 301 0), respectively Median infarct size on SPECT scan was 12 0% (3 0 to 25 0) of the left ventricle Peak TnT and CK-MB demonstrated similar moderate correlation with final infarct size (r = 0 45, p <0 001, and r = 0 41, p <0 001 respectively) This correlation was not affected by Thrombolysis In Myocardial Infarction flow grade after intervention At 1 year, 47 patients (3 8%) had died Final infarct size at SPECT scanning better predicted mortality than peak TnT or CK-MB In conclusion, this study is the largest investigation on the value of cardiac troponin for assessment of infarct size in acute STEMI Compared to peak CK-MB, peak TnT shows similar correlation with scintigraphic infarct size, although scintigraphic infarct size remains a better correlate of 1-year mortality than either biomarker (C) 2010 Elsevier Inc All rights reserved (Am J Cardiol 2010, 106 1212-1217)