Troponin T in Stable and Unstable Angina Pectoris

The aim of the study was to investigate whether or not myocardial damage develops in patients with stable angina pectoris (SAP) and unstable angina pectoris (UAP). We studied 75 patients comprising 48 with UAP and 27 with SAP. Blood samples were taken for CK, CK-MB, LDH, SGOT and cardiac troponin T (cTnT), a new cardiac-specific marker of myocardial damage that is recently in clinical use. The normal range for cTnT was accepted as 0.4 ng/ml. Fourteen healthy volunteers formed the control group in whom cTnT values were normal. However, cTnT was elevated in 29/48 (60%) patients with UAP, 15/27 (56%) patients with SAP. The highest value of cTnT was 1.9 ng/ml in patients with UAP, 1.2 ng/ml in patients with SAP. In none of the patients was CK, CK-MB, LDH or SGOT activity elevated. Three patients with an elevated level of cTnT developed acute myocardial infarction before discharge. In conclusion, the findings of our study suggest that a significant portion of patients with SAP and UAP develops small myocardial injury. These patients were not detected by current routine clinical and laboratory procedures. It remains to be shown whether a poorer prognosis may be expected in these patients, and cTnT may allow selection of patients who may benefit from early intervention.