Comparison of cardiac troponin T versus creatine kinase-MB for risk stratification in a chest pain evaluation unit

We evaluated cardiac troponin T (cTnT) and creatine kinase-MB (CK-MB) for r isk stratification of chest pain unit (CPU) patients. We studied 383 consec utive patients with chest pain assigned to our CPU by emergency department physicians. At baseline all had normal or nondiagnostic electrocardiograms, no high-risk clinical features, and negative CK/CK-MB. CK-MB and electroca rdiograms were taken at 0, 4, 8, and 12 hours and cTnT at 0, 4, and 8 hours . Eight patients (2.1%) were CK-MB positive and 39 (10.2%) were cTnT positi ve, including all but I CK-MB-positive patient. All marker-positive patient s were detected by 8 hours. Seven cTnT-positive patients and 1 cTnT-negativ e patient had myocardial infarction (p <0.0001). cTnT-positive patients wer e order, less likely to be women or smokers, and more often had diabetes me llitus or known coronary disease (CAD). Seventy-one percent of patients und erwent diagnostic testing. cTnT-positive patients more often underwent angi ography (46% vs 20%) and underwent stress testing less often (28% vs 57%) t han cTnT-negative patients. When performed, their stress tests were more of ten positive (46% vs 14%) and they more often had angiographically signific ant lesions (89% vs 49%) and multivessel disease (67% vs 29%). There were n o short-term deaths. Long-term mortality was higher in cTnT-positive patien ts (27% vs 7%, p <0.0001). Thus, cTnT identified more CPU patients with myo cardial necrosis and multivessel CAD than CK-MB and a population with high long-term mortality risk. Routine use of cTnT in CPUs could facilitate risk stratification and management. (C)2000 by Excerpta Medico, Inc.