Beating versus arrested heart coronary revascularization: Evaluation by cardiac troponin I release

Background. This prospective randomized study aimed to compare beating and arrested heart revascularization in patients undergoing first elective coronary artery bypass graft, with cardiac troponin I release used to evaluate myocardial injury. Methods. Seventy patients were randomly assigned to a beating or arrested heart revascularization group. Cardiac troponin I concentrations were measured in serial venous blood samples drawn preoperatively in both groups: after aortic unclamping at 6, 9, 12, and 24 hours in the arrested heart group and after the last anastomosis at 6, 9, 12, and 24 hours in the beating heart group. Analysis of covariance with repeated measures was performed to test the effect of group and time on cardiac troponin I concentration. Results. The total amount of cardiac troponin I released was higher in the arrested heart revascularization group than in the beating heart revascularization group (8.25 +/- 6.16 vs 3.18 +/- 4.75 mug, p < 0.0001). Cardiac troponin I concentrations were significantly higher in the arrested heart group at hours 6, 9, 12, and 24 than in the beating heart group (p < 0.0001). Conclusions. The lower release of cardiac troponin I in the beating heart revascularization group indicates that conventional coronary artery bypass graft with cardioplegic arrest causes more damage to the heart than off-pump myocardial revascularization. (C) 2004 by The Society of Thoracic Surgeons.