Mechanism of Action and Role of Levosimendan in Minimally Invasive CABG

Introduction to Levosimendan

Levosimendan is a calcium sensitizer that improves cardiac contractility by binding to troponin-C in cardiomyocytes while also providing significant vasodilation through ATP-sensitive potassium channels and mild phosphodiesterase inhibitory action, making it valuable for perioperative management in minimally invasive CABG procedures 1, 2

Levosimendan works through calcium sensitization, increasing myocardial contractility by binding to cardiac troponin-C, stabilizing the calcium-bound conformation without increasing intracellular calcium concentrations 1
Levosimendan causes vasodilation by opening ATP-sensitive potassium channels in vascular smooth muscle, leading to significant peripheral and coronary vasodilation 3
Levosimendan has mild phosphodiesterase III inhibitory effects, though this is less significant at therapeutic concentrations 1

A single dose of levosimendan (24 μg/kg over 10 minutes) administered before cardiopulmonary bypass has been shown to reduce time to tracheal extubation, overall ICU length of stay, and postoperative troponin I concentrations 4
Perioperative administration of levosimendan should be considered to reduce the risk of low cardiac output syndrome in patients with reduced left ventricular ejection fraction undergoing isolated CABG 5
Levosimendan decreases the incidence of postoperative atrial fibrillation, myocardial infarction, ICU length of stay, acute renal dysfunction, and ventricular arrhythmias compared to dobutamine 6

The British Journal of Anaesthesia recommends considering levosimendan for patients with reduced left ventricular ejection fraction 5
The European Heart Journal suggests that levosimendan increases cardiac output and stroke volume while reducing pulmonary wedge pressure, systemic vascular resistance, and pulmonary vascular resistance 1
Critical Care guidelines indicate that levosimendan is beneficial for patients with a history of heart failure 6
Patient selection for levosimendan use should include those with risk factors for developing low cardiac output syndrome 4

Monitoring parameters for levosimendan use include cardiac output and stroke volume 2, systemic and pulmonary vascular resistance 1, heart rate, and blood pressure 1
A dosing strategy of 24 μg/kg over 10 minutes before CPB is recommended 4

The European Heart Journal notes that levosimendan has a Class IIb recommendation for treatment of perioperative low cardiac output syndrome, indicating it may be considered 1, 5
Critical Care guidelines suggest that levosimendan has reduced arrhythmogenic potential compared to dobutamine 6