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. Methods: Thirty-eight PTS undergoing myocardial revascularization were randomised 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 measurement prior surgery, 1, 4, 12, 24, 48, 72 h after the procedure. Haemodynamic 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 and no myocardial infarction (MI) in three groups, postoperative haemodynamic measurements showed no significant differences. TnT serum levels were significantly 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 48-h post-operation, Conclusions: Coronary bypass grafting without aortic crossclamping and without CPB offers superior myocardial protection. (C) 1999 Elsevier Science B.V. All rights reserved.