The objective of this project is to compare in a random manner two accepted modes of myocardial preservation, warm and cold blood cardioplegia, coinciding with normothermic and hypothermic cardiopulmonary bypass. Patients will be enrolled in the study if fulfilling entry criteria from the very large group of candidates having coronary revascularization at the Baystate medical Center. Candidates for entry into the study will be patients referred for elective or urgent operation, not having ongoing anginal instability, requiring three or more bypass grafts, and under 70 years of age. All patients will receive a standard anesthetic protocol combining narcotic and inhalational anesthesia. This project will specifically be directed to define differences in neurologic function in patients having normothermic (37 degrees C) or hypothermic perfusion (20 degrees C). Each patient entering the study will have extensive clinical data collected prospectively incorporating most aspects of measurable determinants related to m myocardial preservation. Additionally, neurologic tests will be performed by a blinded neurologist and rated by a well-recognized, objective scoring system, the Mathew scale. These studies will be performed preoperatively, on the third or fourth postoperative day and at one month following surgery. A pilot study of warm versus cold perfusion and preservation was completed in 32 patients preparatory to this proposal. The findings of this study showed 53% of patients had evidence of new neurologic disturbance at postoperative day four. Only the neurologic dysfunction could be correlated with warm vs cold perfusion (37.5% W vs 75% C, p lesser then o.05). The changes in neurologic function had abated or clearly improved by one month of follow-up, and the distinction in neurologic dysfunction grading was no longer apparent between the two groups. The results of the pilot study and the potential for information relative to performance of cardiopulmonary bypass support the necessary performance of this study.
