The effects of retrograde and antegrade delivery of
cardioplegic solution on myocardial function were evaluated and compared in 60 patients who underwent
myocardial revascularization. All patients had three-vessel coronary artery disease, and the revascularization was done with extensive use of the internal mammary artery. Seventy-five percent of the distal anastomoses were performed with the internal mammary artery. Myocardial protection consisted of
St. Thomas' Hospital cardioplegic solution, topical slushed
ice, and systemic
hypothermia (28 degrees C). The patients were randomly separated into two groups: group A (
n = 30), who received antegrade
cardioplegia, and group B (
n = 30), who received retrograde
cardioplegia. With the exception of the total dose of
cardioplegic solution (p = 0.02), there was no significant difference between the two groups that concerned septal myocardial temperature at the moment of
asystole and after infusion of the total dose of
cardioplegic solution. Cardiac function was assessed before and after the patient was weaned from
cardiopulmonary bypass. In the immediate postoperative period there was a significant increase in right atrial pressure of the patients who underwent antegrade
cardioplegia. For the other registered parameters there was no significant difference either in the immediate postoperative period or 6 hours later. Release of
creatine kinase MB isoenzyme was the same in the two groups. Clinical outcome in terms of mortality, prevalence of perioperative
infarction, prevalence of
low cardiac output, and rhythm and conduction disturbances was similar in both groups. Technical problems related to cannulation and decannulation of the coronary sinus were not encountered. Multivariate analysis showed that occlusion of the left anterior descending coronary artery (p = 0.012) is an essential
contraindication of antegrade delivery of
cardioplegic solution. Analysis of the patients with an occlusion of the left anterior descending coronary artery who underwent antegrade (n = 9) and retrograde (n = 10)
cardioplegia showed a significant difference in the total dose of
cardioplegic solution (p = 0.02) and septal myocardial temperature at the moment of
asystole (p = 0.008) and after infusion of the total dose of
cardioplegic solution (p = 0.015). The mean arterial systolic blood pressure in the antegrade group was significantly lower than in the retrograde group (p = 0.003). Preservation of the left ventricular
stroke work index was significantly better in the retrograde group (namely, 85% of its initial value versus 71% in the antegrade group, p = 0.0116).(ABSTRACT TRUNCATED AT 400 WORDS)