Levosimendan Versus Adrenaline in Patients With Low Left Ventricular Function Undergoing Elective On-Pump Coronary Artery Bypass Graft Surgery. A Randomized Controlled Study

Patients undergoing cardiac surgery are at risk of post-cardiotomy myocardial dysfunction. This condition causes delayed recovery, organ failure, prolonged intensive care unit and hospital stays, and an increased risk of mortality. These patients often require inotropic support, which has been associated with an increased risk of cardiovascular complications. Treatment of myocardial dysfunction includes optimization of myocardial contractility through appropriate fluid and pharmacologic management and mechanical support . Extensive use of inotropes in this situation is needed, but the optimal pharmacologic management of myocardial dysfunction in cardiac surgery is a matter of ongoing debate .Available inotropes including adrenaline may increase myocardial oxygen consumption, heart rate and risk of arrhythmia. An increase in myocardial oxygen consumption by inotropes in a state of inadequate oxygen delivery may further deteriorate underlying cardiac dysfunction and even lead to increased mortality . There are questions regarding the ideal inotrope to use during the post cardiopulmonary bypass (CPB) period in patients undergoing on-pump CABG surgery. The occurrence of myocardial dysfunction after cardiac surgery is a potential indication for the use of levosimendan, a calcium sensitizer with a unique mechanism of action. By binding to cardiac troponin C, it enhances myofilament responsiveness to calcium, thereby increasing myocardial contraction without increasing myocardial oxygen consumption. In addition, levosimendan activates adenosine triphosphate-dependent potassium channels, which are important mediators of ischemic and anesthetic cardioprotection. Levosimendan might thus have a potential benefit for patients with myocardial oxygen imbalance requiring inotropic drug support . The hypothesis of the present study is that levosimendan without loading dose can improve myocardial function and provide better hemodynamics as well as echocardiographic parameters compared with adrenaline in patients with low ejection fraction undergoing op-pump CABG