Levosimendan’s effect on coronary artery grafts blood flow in patients with left ventricular dysfunction, assessment by transit time flow meter

Objectives
Levosimendan improves the function of stunned myocardium and cardiac performance in heart failure without significantly increasing myocardial oxygen consumption. We evaluated the effects of levosimendan on hemodynamics and coronary grafts blood flow (CBF) in patients with left ventricular dysfunction undergoing pump coronary artery bypass grafts (CABG) surgery using transit time flow meter (TTFM).
Methods
Twenty patients with stable angina and left ventricular ejection fraction 30–50% scheduled for elective CABG surgery were randomized to receive levosimendan (0.1 mg/kg/min) or placebo, started immediately after induction of anesthesia and continued for 24 h in ICU. Coronary bypass grafts flow was measured 30 min after termination of cardiopulmonary bypass (CPB). Flow curve pattern, mean graft flow, and pulsatile index (PI) were measured and analyzed. Hemodynamics was collected serially at five time points.
Results
Mean flow in all grafts was significantly higher in the Levosimendan group in comparison to control group ( < 0.05). When we compared mean flow between different types of grafts in Levosimendan group, we found that venous sequential grafts had higher flow than non-sequential graft ( < 0.001) and arterial grafts ( = 0.005). Also saphenous vein grafts (SVG) had higher flow in comparison to left internal mammary artery (LIMA) grafts ( = 0.004). As regard PI, it was also more significant in the Levosimendan group for all grafts ( < 0.001) in comparison to control group. Intragroup comparison of PI values between different types of grafts in Levosimendan group showed more significant PI values in sequential grafts ( = 0.002) in relation to SVG, and also it was more significant in comparison to LIMA grafts ( = 0.0027).
Conclusions
Levosimendan significantly increased the flow in arterial and vein grafts after CPB, and improved hemodynamics compared with placebo.