Comparative study of cardiac troponin I and T measurements in a routine extra-cardiological clinical setting

This study compared troponin I (cTnl) to troponin T (cTnT) in a population admitted to General Medicine Divisions in whom acute myocardial infarction (AMI) was suspected; 98 consecutive patients were included. Diagnoses were made without knowledge of troponin results: 51 patients had AMI, and 47 (in cluding 8 with unstable angina) had no AMI. Patients were considered to be troponin positive if the marker concentration was > 99th percentile value o f the reference population, Both troponins were associated with an almost a bsolute sensitivity for AMI (100% for cTnl and 98.0% for cTnT), while the s pecificity was marginally higher for cTnl (78.7% vs. 68.1%). Increased cTnl and/or cTnT were observed in 15 patients out of 39 without acute coronary syndromes. Simultaneous positivity was seen in 8 patients with severe disor ders and complications. Discordances were more frequent in favor of increas ed cTnT (n = 5) than the opposite (n = 2), even if this difference did not achieve statistical significance. cTnl and cTnT detected AMI with comparabl e efficiency. Cases without coronary syndrome positively concordant for tro ponins confirmed the ability of these biomarkers to detect myocardial injur y undetectable by conventional diagnostic approaches. (C) 2001 Wiley-Liss, Inc.