THE MASS CONCENTRATIONS OF SERUM TROPONIN-T AND CREATINE KINASE-MB ARE ELEVATED BEFORE CREATINE-KINASE AND CREATINE KINASE-MB ACTIVITIES INACUTE MYOCARDIAL-INFARCTION

The time-related frequency of elevated results for the mass concentrat ions of the MB isoenzyme of creatine kinase and of troponin T were com pared with that of creatine kinase and creatine kinase-MB activity in patients with acute myocardial infarction. Patients (322; 175 with and 147 without myocardial infarction) consecutively admitted for evaluat ion of possible acute myocardial infarction were investigated. Referen ce limits for troponin T (0.1 mug/1) and creatine kinase-MB mass conce ntration (5.0 mug/1) were exceeded frequently in patients with unstabl e angina pectoris (troponin T 43%, creatine kinase-MB mass concentrati on 24%) in contrast to patients with no acute ischaemic heart disease (both < 5%). Within 4 and between 4-8 hours after onset of chest pain, the frequency of elevated results for creatine kinase-MB mass concent ration and troponin T in patients with acute myocardial infarction was considerably higher (20-30%) than for creatine kinase and creatine ki nase-MB activity. Creatine kinase-MB mass concentration and troponin T both allowed earlier diagnosis of acute myocardial infarction than cr eatine kinase and creatine kinase-MB activity, but troponin T was not elevated before the creatine kinase-MB mass concentration.