Serum cardiac troponin T concentrations in hospitalized patients without acute myocardial infarction

The present study was designed to determine whether the measurement of serum levels of cardiac troponin T (cTnT) would establish the presence of myocardial injury in 79 patients, within 12 h of hospitalization, whose admission and final discharge diagnosis were not related to myocardial infarction. Independent classification by clinicians resulted in 35 (44%) patients characterized as having unsuspected myocardial injury and 44 (56%) without myocardial injury. Increased serum cTnT identified 94% of myocardial injury patients, compared to increased serum creatine kinase MB (CK-MB) mass which identified 69%. Negative serum cTnT and CK-MB concentrations respectively excluded 73 and 50% of patients evidently without myocardial injury, respectively. A total of 12 patients, 9 with and 3 without elevated CK-MB concentration, had unexplained cTnT elevations. While our findings show cardiac troponin T to be more efficient than CK-MB in determining and excluding myocardial injury, even in a randomly selected population with a very high probability, unexplained elevations of cardiac troponin T question its role as an absolute cardiospecific marker.