Evaluation of myocardial protection in off-pump vs. on-pump coronary bypass surgery by troponin I estimation.

BACKGROUND This prospective non-randomized clinical study was done to compare Off-pump and On-pump myocardial revascularization by Troponin I release in patients undergoing first elective coronary artery bypass graft used to evaluate myocardial injury. METHODS One hundred an twenty patients were non-randomly assigned to a Off-pump or On-pump myocardial revascularization group. Cardiac Troponin I (CTnI) were measured in serial venous blood samples drawn preoperatively in both groups. In On-pump group after aortic unclamping at 12 and 24 hours and in Off-pump group after the last distal anastomosis at 12 and 24 hours. RESULTS The total amount of CTnI release were significantly higher in On-pump group than in Off-pump group. In On-pump group it was 2.1 +/- 1.9 (mean +/- SD) ng/ml vs in Off-pump group it was 1.0 +/- 1.7 (mean +/- SD) ng/ml at 12 hours and in On-pump group it was 1.6 +/- 1.6 (mean +/- SD) ng/ml vs. in Off-pump group it was .9 +/- 1.6 (mean +/- SD) ng/ml at 24 hours (P < 0.0001 for the pattern). CONCLUSION The lower release of CTnI in the Off-pump myocardial revascularization group indicates that the arrested heart coronary revascularization group causes more damage to the heart due to cardiopulmonary bypass than Off-pump myocardial revascularization group.