Beating versus arrested heart revascularization: evaluation of myocardial function in a prospective randomized study

Objective: Conventional coronary artery bypass grafting (CABG) is both safe and effective. Nevertheless, the use of cardiopulmonary bypass (CPB) and c ardioplegic arrest are associated with several adverse effects. Over the la st 2 years there has been a revival of interest in performing CABG on the b eating heart. In this prospective randomized study we evaluated the efficac y and safety of on and off pump coronary revascularization on myocardial fu nction. Methods: Eighty patients (65 males, mean age 61 +/- 9.7 years) unde rgoing first time CABG were prospectively randomized to: (i) conventional r evascularization with CPB at normothermia and cardioplegic arrest with inte rmittent warm blood cardioplegia ton pump) or (ii) beating heart revascular ization (off pump). Troponin I (Tn I) release was serially measured as a sp ecific marker of myocardial damage. Haemodynamic measurements as well as in otropic requirement, incidence of arrhythmia and postoperative myocardial i nfarction were also recorded. Results: There were no significant difference s between the two groups in terms of age, sex, extent of disease, left vent ricular function and number of grafts. There were no deaths or intraoperati ve myocardial infarctions in either group. Tn I release was constantly lowe r in the off pump group and this was significant at 1, 4, 12 and 24 h posto peratively. Furthermore, in this group there was a significantly reduced in cidence of arrythmias. Inotropic requirements were less in the on pump grou p but this did not reach statistical significance. Conclusion: These result s suggest that off pump coronary revascularization is a safe and effective strategy for myocardial revascularization. Myocardial injury as assessed by Tn I release is also reduced when compared with conventional coronary reva scularization with CPB and cardioplegic arrest. (C) 1999 Elsevier Science B .V. All rights reserved.