Noncardioplegic myocardial preservation for coronary revascularization

Hypothermic potassium cardioplegia has become the most popular technique for myocardial preservation during coronary revascularization. However, an older technique continues to yield comparable results with some potential advantages. Myocardial preservation was achieved with systemic hypothermia to 28 degrees C, pericardial cooling, elective ventricular fibrillation, maintenance of systemic perfusion pressure between 80 and 100 mm Hg, routine left ventricular venting, and local vessel isolation during distal anastomoses without aortic occlusion. Proximal anastomoses were performed prior to atrial cannulation and cardiopulmonary bypass. Nonemergency isolated bypass grafting was performed in 500 consecutive patients, of whom 51% had had a prior myocardial infarction, 24% had unstable angina, and 21% had left main coronary stenosis. Primary grafting was performed in 483 patients and reoperations in 17. The mean number of grafts per patient was 3.8. Perioperative myocardial infarction occurred in 1.8%. Hospital mortality was 0.4%. Late follow-up was obtained for all survivors at a mean postoperative interval of 17.8 months. All survivors were asymptomatic or improved over their preoperative status. The 3 year actuarial survival rate was 95.8%, equivalent to that for the matched general population. Of 287 male patients under age 65, 68.4% were working preoperatively and 69.5% postoperatively. This technique provides results comparable to bypass grafting with cardioplegia and may be useful when aortic occlusion or administration of cardioplegic solutions is not desirable.