NEUROLOGIC EVENTS AFTER CORONARY-BYPASS GRAFTING - FURTHER OBSERVATIONS WITH WARM CARDIOPLEGIA

Warm heart surgery has documented myocardial protection benefit, but w ith an added neurologic threat. It is hypothesized that moderately hyp othermic aerobic heart surgery will maintain the myocardial protection and reduce neurologic risk. This study compared 493 patients undergoi ng coronary artery bypass graft operations with normothermic (35 degre es to 37 degrees C) continuous blood cardioplegia and normothermic per fusion to 379 coronary artery bypass grafting patients with hypothermi c (33 degrees to 29 degrees C continuous blood cardioplegia and hypoth ermic perfusion to test this hypothesis. There was no difference in ag e, sex, prior myocardial infarction, hypertension, prior neurologic ev ent, congestive failure, or diabetes. The hypothermic group had more r eoperations (24% versus 14%; p = 0.0002), class III/IV angina (83% ver sus 71%; p = 0.002), a trend to mole triple-vessel (54% versus 47%; p = 0.10) and left main disease (18% versus 14%; p = 0.10), lower ejecti on fractions (0.52 +/- 0.15 versus 0.55 +/- 0.13), more grafts placed (3.6 +/- 1.1 versus 3.4 +/- 1.1; p = 0.04), but fewer internal mammary arteries (62% versus 78%; p < 0.0001). Postoperative myocardial infar ction rate was 1.2% in the hypothermic group and 1.3% in the normother mic group (p = not significant). Intraaortic balloon pump requirement was 3.4% with hypothermic and 1.4% with normothermic groups (p = 0.05) . The incidence of postoperative neurologic events was significantly h igher in the normothermic group (4.7% versus 1.8%; p = 0.038). The mul tivariate correlates of stroke were older age and normothermic cardiop legia, whereas the only multivariate correlate of death was older age. In summary, these data suggest that hypothermic continuous blood card ioplegia provides myocardial protection that is equivalent to normothe rmic continuous blood cardioplegia, whereas hypothermic aerobic heart surgery may lessen the neurologic risk that was observed associated wi th strict warm heart surgery.