MYOCARDIAL PROTECTION IN DIFFUSE CORONARY-ARTERY DISEASE - INTERMITTENT RETROGRADE COLD-BLOOD CARDIOPLEGIA AT SYSTEMIC NORMOTHERMIA VERSUS INTERMITTENT ANTEGRADE COLD-BLOOD CARDIOPLEGIA AT MODERATE SYSTEMIC HYPOTHERMIA

In order to determine the comparative merits of antegrade cardioplegia at moderate systemic hypothermia versus retrograde cardioplegia at sy stemic normothermia, we performed coronary artery bypass grafting usin g intermittent oxygenated blood cardioplegia in 2 sets of 50 consecuti ve patients with triple-vessel disease (complete occlusion of 1 corona ry artery and greater than 90% narrowing of the other 2, with poor dis tal runoff). Group 1 had antegrade cardioplegia at moderate systemic h ypothermia (28-degrees-C). Group 2 had retrograde cardioplegia at syst emic normothermia. This resulted in no deaths and in no differences in complication rates. Group 2's postoperative need for inotropic agents or vasodilators was significantly less (epinephrine, p < 0.0009; dopa mine, p < 0.002; nitroglycerin, p < 0.001). Elevations of CKMB fractio n were significantly more common in Group 1: 46% had CKMB levels great er than 9%, versus 16% of Group 2 patients (p <0.0001). Intraoperative transesophageal echocardiography was performed in 39 Group-1 patients and in 42 Group-2 patients. Development of a new wall-motion abnormal ity after bypass was significant only in Group 1 (p < 0.009, by chi2 a nalysis). We conclude that retrograde cardioplegia at normothermia pro vides myocardial protection that equals or surpasses that of antegrade delivery at moderate systemic hypothermia, while avoiding the possibl e deleterious side effects of hypothermia.