Cardiac troponin T release during coronary surgery using intermittent cross-clamp with fibrillation, on-pump and off-pump beating heart

Objective: Troponin T is a unique marker which might be particularly useful in assessing myocardial cell damage in patients undergoing cardiac surgery . The aim of the study was a comparison between intra-operative release of troponin T (TnT) during three different myocardial protection strategies. M ethods: Thirty-eight PTS undergoing myocardial revascularization were rando mised into 3 groups in whom procedure was performed with intermittent cross -clamp (Group I; n = 13), beating-heart on pump without aortic cross-clamp (Group II; n = 12), beating-heart without use of extracorporeal circulation (Group III; n = 13). Serial venous blood samples were collected for TnT me asurement prior surgery, 1, 4, 12, 24, 48, 72 h after the procedure. Haemod ynamic measurements were made using a thermodilution PA catheter. Results: The groups were similar with respect to age, sex, preoperative LV function, number of grafts, potential risk factors. There were no hospital deaths an d no myocardial infarction (MI) in three groups, postoperative haemodynamic measurements showed no significant differences. TnT serum levels were sign ificantly higher in group I when compared to groups II and III. TnT levels were significantly lower in group III when compared to group TI following 4 8-h post-operation, Conclusions: Coronary bypass grafting without aortic cr ossclamping and without CPB offers superior myocardial protection. (C) 1999 Elsevier Science B.V. All rights reserved.