Myocardial Protection During Coronary Artery Bypass Graft Surgery

Abstract

We conducted a randomized, double-blind, placebo-controlled study to assess the cardioprotective effects of trimetazidine (TMZ), an antiischemic drug, on left ventricular function using transesophageal echocardiography (TEE) after coronary artery bypass grafting (CABG). Forty patients undergoing elective CABG received either TMZ or a placebo (PCB). The primary measures of efficacy were serial measurements of fractional area change (FAC), percent of systolic wall thickening (SWT), and malonedialdehyde (MDA) production. The two groups were similar for the following variables: number of vessels revascularized (2.5 +/- 0.2 in the TMZ group and 2.8 +/- 0.1 in the PCB group), duration of aortic clamping (46 +/- 4 min in the TMZ group and 48 +/- 3 min in the PCB group), and bypass time (63 +/- 4 min in the TMZ group and 70 +/- 4 min in the PCB group). FAC increased by 12% in both groups 20 min after aortic unclamping (P < 0.05) and remained above the initial value at the sixth postoperative hour. SWT was 23.8% +/- 1.6%, 25.4% +/- 1.9%, then 21.6% +/- 1.5% in the TMZ group and 22.8% +/- 1.6%, 23.8% +/- 1.4%, then 22.3% +/- 1.6 % in the PCB group, after induction of anesthesia and 1 and 6 h after aortic unclamping (not significant). MDA increased by 24% in the PCB group and 25% in the TMZ group 20 min after aortic unclamping (P < 0.01). Lactate levels were lower in the TMZ group (P < 0.05) and patients from the TMZ group received less intravenous calcium before aortic clamping (P < 0.02) and less calcium channel entry blocking drugs in the early phase after aortic unclamping (P < 0.01) compared to the PCB group. We conclude that in patients with good preoperative ejection fraction undergoing CABG, TMZ as administered did not demonstrate clinically significant cardioprotective effects on left ventricular performance and lipid peroxidation compared to PCB.