Insulin cardioplegia for elective coronary bypass surgery

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1067/mtc.2000.105257 Byline: Vivek Rao, Michael A. Borger, Richard D. Weisel, Joan Ivanov, George T. Christakis, Gideon Cohen, Terrence M. Yau Abstract: Background: Improved methods of myocardial preservation are required to reduce the morbidity and mortality of coronary bypass surgery for high-risk subgroups. Metabolic stimulation with insulin, glucose solutions, or both has been proposed as a method to preserve the ischemic myocardium. We performed a prospective, double-blind, randomized trial to evaluate the effects of insulin and glucose as cardioplegic additives when used as part of a tepid continuous blood cardioplegic strategy. Methods: We randomized 56 male patients undergoing elective isolated coronary bypass surgery to 1 of 4 cardioplegic groups containing either 42 or 84 mmol/L glucose with or without 10 IU/L of insulin. Perioperative assessments of myocardial metabolism and left ventricular function were performed. Results: Insulin-enhanced cardioplegia was associated with beneficial effects on both myocardial metabolic and functional recovery after cardioplegic arrest. Insulin's effect was independent of the ambient glucose concentration. Conclusions: Cardioplegic formulations containing a 42 mmol/L concentration of glucose and a 10 IU/L concentration of insulin provide significant benefit to patients undergoing isolated coronary bypass surgery. The clinical effect of these formulations will need to be assessed in high-risk subgroups of patients, such as those with unstable angina, recent myocardial infarction, or poor left ventricular function. (J Thorac Cardiovasc Surg 2000;119:1176-84) Author Affiliation: Toronto General Hospital and Sunnybrook Health Science Centre at The University of Toronto, Toronto, Ontario, Canada Article History: Received 3 September 1999; Revised 28 October 1999; Revised 7 December 1999; Accepted 20 December 1999 Article Note: (footnote) [star] Supported in part by the Heart and Stroke Foundation of Canada (grants NA3767 and NA4189) and the Medical Research Council of Canada (grant MT13513). V.R., M.A.B., and G.C. are Research Fellows of the Heart and Stroke Foundation of Canada. T.M.Y. is a Research Fellow of the Medical Research Council., [star][star] Address for reprints: Richard D. Weisel, MD, Chair, Division of Cardiovascular Surgery, EN 14-215, The Toronto Hospital, 200 Elizabeth St, Toronto, Ontario, Canada M5G 2C4., a *For a listing of the Insulin Cardioplegia Trial (ICT) Investigators, see the appendix.