Clinical significance of myoglobin and troponin-T in short-lasting severe myocardial ischemia

Background: Myoglobin, cardiac troponin-T and creatine phosphokinase are biochemical indicators of acute coronary syndromes, however, the clinical significance in myocardial ischemia is not well established. Our aim was to elucidate their release kinetics in a well-defined short-lasting myocardial ischemia. Methods: A coronary sinus lactate study with incremental atrial pacing was performed in 27 patients with significant coronary stenosis. Troponin-T, myoglobin and creatine phosphokinase samples were withdrawn from the coronary sinus and a peripheral vein before, 1, 5, 10, 30, 45 min and 1, 2, 3, 6, 12 h after pacing. Results: Pacing stress induced a severe myocardial ischemia with a duration of 5.8±1.6 min, angina pectoris in 22/27, significant ST-segment depressions in 25/27 patients (0.34±0.11 mV) and a frank cardiac lactate production of 37.6±19.9%. Serum troponin-T levels as well as creatine phosphokinase were normal at baseline and remained unchanged. A transient rise of myoglobin after 1 h with a peak coronary sinus concentration after 2 h (101.5±39.0 μg/l) and peripheral venous concentration (90.5±32.5 μg/l) after 3 h (134.3% and 120.7%, respectively, of the upper normal limit, p