Beta-blockade versus Buckberg blood-cardioplegia in coronary bypass operation

Objective: Continuous perfusion of the coronary arteries with beta-blocker (esmolol)-enriched normothermic blood during cardiac surgery has been sugge sted as an alternative technique for myocardial protection. The aim of the present study was to compare the beta-blocker technique to Buckberg's blood cardioplegia during coronary artery bypass grafting (CABG). Methods: Sixty patients with coronary artery disease were randomly assigned to either the esmolol group (ES, n = 30) or the blood cardioplegia group (BC, n = 30). D uring aortic crossclamp ES patients received continuous normothermic corona ry perfusion with esmolol-enriched blood. Hearts of the BC group were prote cted by antegrade cold blood cardioplegia according to Buckberg. We measure d left ventricular (LV) contractility using TEE (fractional area of contrac tion, FAG) and hemodynamic parameters prior to cannulation for cardiopulmon ary bypass (CPB), after decannulation, and 4 h postoperatively. Myocardial lactate release was measured prior to aortic cross-clamp, during cross-clam p, and after decannulation. LV biopsies for determination of heat-shock pro tein (HSP-70), actin pattern and intercellular adhesion-molecule (ICAM-I) a s indicators for structural changes were collected prior CPB, at the end of the aortic cross-clamp period, and prior to weaning off CPB. Results: Ther e was no significant difference between both groups with respect to grafts and cross-clamp time. ES hearts did not release lactate during cross-clamp. In contrast, BC hearts released significant amounts of lactate. Post CPB F AC and hemodynamics under similar inotropic stimulation showed no differenc e between groups, whereas at 4 h post CPB measurements showed slightly bett er values in the ES group: cardiac index: ES: 2.9 +/- 0.1 (SEM) versus BC: 2.6 +/- 0.1 L/min per m(2) (P < 0.05); FAG: ES: 55 +/- 3 versus BC: 48 +/- 3% (P < 0.05). HSP-70 and actin pattern showed no difference between groups ; however, ICAM-I showed a significantly higher degree of structural change s in BC hearts: 18 +/- 2 versus ES: 11 +/- 1% (P < 0.05). Conclusion: Our d ata demonstrate that application of the beta-blocker technique during routi ne CABG was associated with slightly better functional recovery and less st ructural myocardial alteration as compared with intermittent cold blood car dioplegia, however, both techniques provided equivalent myocardial protecti on in terms of patient outcome. Future studies are required to investigate if myocardial ischemia minimization by use of the beta-blocker technique ma y be beneficial in compromized hearts. (C) 1999 Elsevier Science B.V. All r ights reserved.