DOES RETROGRADE ADMINISTRATION OF BLOOD CARDIOPLEGIA IMPROVE MYOCARDIAL PROTECTION DURING FIRST OPERATION FOR CORONARY-ARTERY BYPASS-GRAFTING

Background. The objective of this study was tea evaluate the value of retrograde blood cardioplegia in coronary artery bypass grafting. Meth ods. In 1994 and 1995, 224 patients undergoing first-time isolated cor onary artery bypass grafting were randomized to antegrade (112 patient s, group If or retrograde (112 patients, group 2) administration of bl ood cardioplegia. In group 1, 76 patients were given warm cardioplegia (at 33 degrees C) and 36 had cold cardioplegia (<20 degrees C), where as in group 2 cardioplegia was warm in 77 patients and cold in 35. The two randomization groups had similar demographic and angiographic cha racteristics. The number of grafted coronary arteries averaged 2.9 +/- 0.7 in group 1 and 2.8 +/- 0.7 in group 2. Total duration of cardiopu lmonary bypass (78 +/- 23 and 75 +/- 21 minutes) and of aortic cross-c lamping (47 +/- 16 and 46 +/- 16 minutes), total volume of infusion of the crystalloid component of cardioplegia (988 +/- 297 and 1016 +/- 5 95 mL, and total duration of infusion of cardioplegia (23 +/- 10 and 2 2 +/- 11 minutes) were similar (p > 0.05). Results. There was no death in group a and one in group 2 as a result of a pulmonary embolus, for a global early mortality of 0.45%. The numbers of perioperative myoca rdial infarction (5 versus 3), congestive heart failure (4 versus 5), postoperative hemorrhage (4 versus 4), and stroke (1 versus 2) were al so similar (p > 0.05). Release curves of total creatine kinase, creati ne kinase-MB by serum activity and mass concentration, and troponin T were not significantly different (p > 0.05) between the two groups, Fo r the 216 patients without perioperative myocardial infarction, peak e nzyme release of creatine kinase-MB at 24 hours averaged 23+/-22 and 2 0+/-18 IU/L, and that of troponin T averaged L1+/- 1.1 and 1.3 +/- 1.5 mu g/L at 6 hours for the antegrade and the retrograde groups, respec tively (p > 0.05). Conclusions. Our results indicate no evidence that the retrograde method of cardioplegic infusion improves myocardial pro tection during first operation for isolated coronary revascularization compared with the usual antegrade route. (C) 1997 by The Society of T horacic Surgeons.