Troponin-T in patients with unstable and stable angina pectoris undergoing coronary bypass surgery

BACKGROUND: Troponin-T is a sensitive indicator of minor myocardial damage during coronary bypass surgery. METHODS: Troponin-T levels were assessed before and repeatedly for 64 hours after coronary bypass surgery in 100 patients with unstable and 100 with stable angina pectoris. RESULTS: Postoperative troponin-T levels rose significantly within 6 hours followed by a decline until 64 hours. In unstable patients who had pain within two days and an acute myocardial infarction within two weeks before the operation (Braunwald class IIIC), Troponin-T rose to high levels that persisted for 64 h. Sixty-seven percent of these patients had an elevated troponin-T >0.10 microg/l already before the operation and a perioperative myocardial infarction was recorded in 27%. In contrast, postoperative troponin-T levels in remaining patients classified as unstable were similar to those in patients with stable angina. Elective operations in the control group were performed with a low risk of adverse postoperative events. CONCLUSIONS: Patients with Braunwald class IIIC unstable angina suffered to a great extent myocardial cell damage following coronary bypass surgery.