Perioperative myocardial cell injury: The relationship between Troponin T and cortisol

Study Objective: To investigate whether there is an association between Tro ponin T (TnT), reflecting myocardial, cell injury, and cortisol, reflecting the degree of surgical trauma and associated stress, in light of our recen t evaluation of TnT as a marker of perioperative myocardial cell injury. Design: Prospective, cohort study. Patients: 70 patients (67.4 +/- 8.7 yrs) with definite or at-risk coronary artery disease (CAD) undergoing elective noncardiac surgery (vascular n = 3 8, abdominal n = 21, orthopedic n = 8) with general (n = 63) or regional (n = 4) anesthesia with postoperative on-demand analgesia. Measurements and Main Results: Morning blood samples for TnT (upper limit o f normal: < 0.2 ng/mL), CK-MB (reference range less than or equal to 12 U/L ), and cortisol (normal morning range 7-25 mu g/dL) were taken on the day b efore surgery, on the morning of surgery before induction of anesthesia, an d on the first 5 postoperative days. Data were compared by analysis of vari ance. Three patients were excluded from the study because of incomplete blo od samples of TnT or cortisol. Preoperative mean cortisol levels (mu g/dL /- SD) were within the normal range and equal in TnT positive (n = 13) and negative (n = 54) patients (16.1 +/- 4.5 vs. 15.6 +/- 5.8). On the 1st post operative day, there was a substantial increase of cortisol in the TnT posi tive group (35.7 +/- 26.9). Cortisol remained high until the 5th postoperat ive day (24.7 +/- 9.4). There was a significant difference in the cortisol concentration in TnT-positive compared to TnT-negative patients (p < 0.001) , a significant difference in the perioperative cortisol concentration over time (p < 0.05), and a significant interaction (p < 0.01). But there was n o consistent temporal relationship between the increase of TnT and the incr ease of cortisol. Conclusions: The significant relationship between a highly sensitive and sp ecific marker of myocardial cell injury and a marker of stress suggests tha t cardiac-risk patients undergoing stressful surgical procedures might bene fit from close perioperative TnT monitoring with early recognition of myoca rdial cell injury. (C) 2000 by Elsevier Science Inc.