A comparison of ischemic preconditioning versus terminal warm cardioplegiawith controlled reperfusion in open heart operation

Background The purpose of this study was to evaluate the effects of three d ifferent methods of cardioprotection in patients undergoing valve replaceme nt, Methods. Ninety patients undergoing elective valve replacement were randoml y divided into three groups. In group 1 (n = 30), the patients received int ermittent cold blood cardioplegia. In group 2 (n = 30) they received termin al warm cardioplegia and controlled reperfusion, and in group 3 (n = 30), t he patients received two cycles of ischemia (2 minutes) and reperfusion (3 minutes) before heart arrest induced by cold blood cardioplegia, The parame ters of cardiac function, creatine kinase MB, and clinical outcomes were re corded to assess the effects of experiment. Results. The major preoperative and intraoperative variables are comparable within the three groups. The number of patients requiring the support of i notropic agents was 70% (21/30), 33% (11/30) and 40% (12/30) in group 1, 2 and 3, respectively (p < 0.05), The doses of inotropic agent in groups 2 an d 3, were significantly lower than in group 1 (1.5 <plus/minus> 0.3 and 1.8 +/- 0.4 versus 4.5 +/- 0.8 mug.kg.min(-1), p < 0.01) during the first 24 h ours after operation. Two deaths (30 day-hospital mortality) occurred, one in group 1 and one in group 2, The cardiac index at 2 hours after bypass di scontinuing were 2.2 <plus/minus> 0.04, 3.0 +/- 0.1 and 2.8 +/- 0.05 L/m(2) In group 1, 2 and 3, respectively (p < 0.01), The left ventricular stroke work index were 24.8 <plus/minus> 1.3, 34.5 +/- 1.6 and 31.6 +/- 1.2 g/m.m( 2) in group 1, 2, 3, respectively (p < 0.01). The release of CK-MB in group 2 and 3 were lower than in group 1 (68 <plus/minus> 7, 81 +/- 9 versus 116 +/- 10 IU/L, p < 0.01). Conclusions. Terminal warm cardioplegia with controlled aortic root reperfu sion and ischemic preconditioning equally improve cardiac function and redu ce the requirement of inotropic agents in patients undergoing valve replace ment.