Coronary artery bypass without cardioplegia.

Cardioplegic myocardial protection has become the standard for coronary artery bypass. In contrast, we report 500 consecutive coronary artery bypass operations with intermittent aortic clamping for distal anastomoses, left ventricular venting, and 30 degrees C hypothermia. Average patient age was 62 years (range of 30 to 89 years). The number of patients who had urgent or emergency operations was 194 (39%); 251 patients had unstable angina, and 123 others had preinfarction angina (pain at rest in the hospital); 27 had evolving myocardial infarction. The average number of grafts was 3.3 per patient, and the average ischemic time was 7.65 minutes per graft. There were five hospital deaths (1%); none resulted from poor myocardial protection that caused low cardiac output. Only three survivors (0.6%) required a balloon pump to be weaned from cardiopulmonary bypass: two had acute infarctions preoperatively, and the other had an ejection fraction of 0.30 and intractable atrial arrhythmias. Only two other patients (0.4%) received any inotropic infusions postoperatively. Eighteen patients (3.6%) had a perioperative infarction. These results, particularly the virtual absence of postoperative inotropic support, in unselected patients of whom 80% had acute coronary syndromes, indicate that intermittent ischemia can provide excellent myocardial protection for coronary bypass. Brief periods of intermittent ischemia alleviate concern about cardioplegic protection via occluded coronaries or internal mammary grafts and provide a simple and safe option for myocardial protection during coronary artery bypass.