EARLY ASSESSMENT OF REPERFUSION THERAPY USING CARDIAC TROPONIN-T

Objectives. The purpose of this study was to investigate the utility of cardiac troponin T for early assessment of reperfusion therapy. Background. Several biochemical markers are used for early noninvasive detection of reperfusion during intravenous thrombolytic therapy. However, cardiac troponin T, a new myocardial-specific marker, has not been used previously for this purpose. Methods. We measured troponin T and creatine kinase, MB isoenzyme (CK-MB) levels in 38 patients with acute myocardial infarction whose infarct related artery was totally occluded before reperfusion therapy. Subjects comprised 14 patients with successful angioplasty (group 1), 12 patients with successful thrombolytic therapy (group 2) and 12 patients with unsuccessful attempted reperfusion (group 3). Blood samples were taken every 15 min, and coronary angiography was performed every 5 to 8 min until 60 min after reperfusion (groups 1 and 2) or after the initiation of treatment (group 3). We calculated the increase in troponin T (Delta troponin T) and CK-MB (Delta CK-MB) 60 min after treatment was initiated and 60 min after reperfusion in groups 1 and 2. Results. Mean (+/-SD) Delta troponin T and Delta CK-MB levels were 9.35 +/- 7.83 ng/ml and 125 a 83 mU/ml in group 1 and 3.23 +/- 3.08 ng/ml and 130 +/- 137 mU/ml in group 2, respectively, 60 min after treatment and were 10.1 +/- 8.35 ng/ml and 131 a 84 mU/ml in group 1 and 6.84 +/- 8.30 ng/ml and 158 +/- 146 mU/ml in group 2, respectively, 60 min after reperfusion. These values were sig significantly higher than those 60 min after treatment in group 3: 0.16 +/- 0.19 ng/ml and 10 +/- 9 mU/ml, respectively. The predictive accuracy for detecting reperfusion using a threshold value of 0.50 ng/ml of Delta troponin T and 25 mU/ml of Delta CK-MB was 100% in group 1 and 92% in group 2 60 min after treatment, respectively. There was significant correlation between Delta troponin T and Delta CK-MB. Conclusions. Serial measurements of cardiac troponin T as well as of CK-MB are useful for early assessment of reperfusion therapy.