Response of internal mammary artery wall to L-carnitine in patients undergoing coronary artery bypass

Abstract

BACKGROUND: This study attempts to highlight the vasodilatation effects of L-carnitine on the left internal mammary artery (LIMA) in patients undergoing coronary artery bypass graft (CABG) surgery. PATIENTS AND METHODS: A total of 45 male patients (age 55–60 years), and body weight (70–75 kg) were included in this study. Participants were planned to undertake elective CABG surgery, and they were randomly allocated into two study groups as follows: Control group included 15 patients received placebo capsule (lactose capsules), twice daily for 3 successive days before CABG surgery. L-carnitine-treated group included the remaining 30 participants received L-carnitine capsules, 500 mg twice daily for 3 days before CABG surgery. RESULTS: The two groups were comparable according to their age and comorbidities. There was significant increase in the plasma levels of endothelial nitric oxide synthase (eNOS) and matrix Gla-protein (MGP) among the L-carnitine group as compared with the control group (P < 0.001, P = 0.011, respectively). At the same time, tissue eNOS levels and tissue MGP levels were significantly higher (P = 0.078, P < 0.001, respectively) in the L-carnitine group as compared with the control group. Plasma levels of angiotensin II (ANGII) and endothelin-1 (ET-1) levels were significantly lower (P < 0.001) in the L-carnitine group. Tissue levels of ANGII and ET-1 were significantly lower (P = 0.039, P < 0.001, respectively). CONCLUSIONS: We can conclude that L-carnitine has potent vasodilatation effects on LIMA during CABG surgery as evidenced by the increase in plasma and tissue levels of eNOS and MGP, associated with a decrease in plasma and tissue levels of ANGII and ET-1.

Keywords

• coronary artery bypass graft
• l-carnitine
• left internal mammary artery
• papaverine
• vasodilator