Perioperative ST-segment depression and troponin T release - Identification of patients with highest risk for myocardial damage

Background: patients undergoing major vascular surgery are at constant risk of developing perioperative myocardial complications, especially myocardia l infarction. The following study was performed to answer the question whet her ST segment changes, analysed by Holter monitoring and ST segment analys is, are accompanied by release of cardiac troponin T, a highly specific mar ker of myocardial damage. Methods: Tventy patients undergoing elective aortic resection were studied by performing Holter EGG, including ST segment analysis, beginning on the e vening before surgery until the third postoperative day. Within this period serum levels of cardiac troponin T were determined at 8 timepoints. Results: A total of 8/20 of the patients (40%) showed significant ST depres sions (range -0.17/-0.68 mV), without any clinical symptom, with a median o f 9 episodes (range 2-24). In 3 of the 8 patients, each with repetitive per iods of ST depression, elevated troponin T levels were found (0.45/0.52/1.6 9 mu g/l). No troponin T release nor cardiac events were noticed in the rem aining patients. No dependancy could be found between troponin T release an d the magnitude of ST depression or the number of ST depression episodes. Conclusion: Haemodynamic changes,oxygen imbalance and stress during major v ascular surgery frequently lead: to an ischaemic burden, which is indicated by ST segment changes during ECG ST analysis. Longlasting ST depression re aching an individual critical cut-off limit, followed by structural myocard ial damage may be verified by elevated levels of cardiac troponin T. Prolon ged periods of ST depression should be followed by determination of cardiac troponin T.