A Retrospective Comparative Study between Levosimendan and Adrenaline as a Pharmacological Protocol for the Management of Coronary Artery Bypass Grafting Patients with Low Ejection Fraction: A Friend or Foe

Background: Left ventricular ejection fraction is an independent determinant of the outcome of coronary artery bypass surgery. Low preoperative ejection fraction requires special care in terms of pharmacological and mechanical inotropic support. Adrenaline is the most widely used inotropic drug, while levosimendan is a relatively new inotropic drug in the field of cardiac surgery. In this study, we aimed to evaluate the relative efficacy of levosimendan in low ejection fraction patients undergoing coronary artery bypass grafting (CABG). Methods: A retrospective comparative study was performed with 63 patients who underwent isolated on-pump elective CABG with a preoperative ejection fraction below 40%. Patients were allocated to the adrenaline group (n = 35) and levosimendan group (n = 28). Patients were further stratified according to ejection fraction above 30% and below or equal to 30%. The primary outcome was cardiac-related mortality, while other parameters were considered secondary endpoints. Results: EuroSCORE of the adrenaline group was 3.34 ± 1.26 and for the levosimendan group 3.15 ± 1.42 (p value 0.576). Nine patients of the adrenaline group had new postoperative atrial fibrillation compared to seven patients in the levosimendan group (p value 0.948). Two patients of the adrenaline group had postoperative ventricular arrhythmia compared to only one patient in the other group (p value 0.691). The adrenaline group had higher doses of inotropic support compared to the levosimendan group 210.84 ± 23.74 and 157.4 ± 22.69 ng/kg/min respectively (p value < 0.001). Longer ventilation hours and overall duration of ICU stay were also noticed in the adrenaline group 32.57 ± 7.23 hours, 8.84 ± 3.28 days in comparison to the levosimendan group 24.37 ± 5.09 hours, 6.23 ± 2.37 days (p values < 0.001 and 0.002 respectively). However, the primary endpoint was not significantly different between the two groups. Conclusions: The levosimendan-based protocol failed to improve overall mortality in low ejection fraction patients undergoing CABG. However, this protocol significantly reduced the dose of inotropic and vasoconstrictor support needed, ventilation hours and duration of ICU stay.