Myocardial Protection in Diabetics With Left Main Stem Disease: Which is the Best Strategy?

Background: Diabetes mellitus is a well known risk factor for extensive coronary disease. The optimal route for cardioplegia administration in patients with severe ischaemic heart disease undergone surgery, especially with left main stem disease (LMSD) is still under debate. Aim of the study is to compare 2 different strategies of myocardial protection in diabetics with LMSD.

Methods: Between January 2000 and June 2003 90 consecutive patients with type II diabetes mellitus and LMSD undergoing isolated myocardial revascularization were divided into 2 groups according to the route of cardioplegia delivery: antegrade in 45 patients (group A), antegrade followed by intermittent retrograde in 45 (group B). ECG, Troponin I, MB-CPK, MB-CPK mass were performed at 12, 24, 48, and 72 hours postoperatively. Echocardiography was performed preoperatively and before hospital discharge.

Results: Groups were homogeneous in preoperative and intraoperative variables, apart from higher incidence of unstable angina and longer cardiopulmonary bypass time in Group B and hypertension in Group A. Hospital deaths, in intensive care units (ITU) stay, perioperative acute myocardial infarction, intra-aortic balloon pump support, postoperative recovery of left ventricle ejection fraction and wall motion score index were similar in both groups. In hospital stay proved shorter in group B (p=0.002), whereas postoperative atrial fibrillation was higher in group A (p<0.001), as postoperative inotropic support (p=0.006). Troponin I proved significantly higher in group A from the 12 degrees to the 72 degrees postoperative hour (p<0.0001).

Conclusions: Despite major in hospital end-points did not differ with strategy of cardioplegia administration, combined route of intermittent blood cardioplegia allows better biochemical and perioperative results in diabetics with LMSD.