Coronary bypass with substrate-enhanced cardioplegia versus non-cardioplegic technique for early revascularization in acute infarction

Abstract

Nine patients chosen at random received substrate enhanced cardioplegia(SECP) for early (less than 4 h) revascularization in acute infarction. Acontrol group of 9 patients with similar clinical characteristics waschosen from the larger group revascularized concurrently with anoncardioplegic technique (NCP). There were no significant differencesbetween the NCP and SECP groups respectively in preoperative clinicalparameters such as age (62.8 vs. 62.3 years), sex (7 men, 2 women in bothgroups), ejection fraction (50% vs. 56%) or number of diseased vessels (2.1vs 2.3). Intraoperative aortic clamp times were significantly shorter inNCP patients (11 vs. 38 min), and 4 NCP patients had no clamping. Theinternal mammary artery (IMA) was used in 6 NCP patients and 1 SECP patient(to a nonoccluded branch vessel). Postoperatively, NCP patients had higherpeak CPK-MB (284 vs. 190 IU/l), longer use of inotropes (10 vs. 2.7 h) andintraaortic balloon pump (15 vs. 8 h), and a higher ejection fractionbefore discharge from hospital, but none of these differences weresignificant. SECP appears to provide better myocardial performance earlypostoperatively, but lasting benefits were not apparent in this subset ofpatients with early revascularization. Because the IMA has a powerfuleffect on long term survival but is very difficult to use with antegradeSECP, we continue to favor the IMA without SECP in hemodynamically stable,young patients (less than 65 years) who are revascularized early afterinfarction.