Levosimendan vs. Dobutamine in Patients with Severe Reduced Left-ventricular Function Undergoing Off-pump Coronary Artery Bypass Surgery

Objectives: Left ventricular poor function is associated with low cardiac output after off pump coronary artery bypass grafting. Effect of levosimendan is discussed controversial.

Methods: We evaluated retrospectively the efficacy and safety of levosimendan in patients with a left ventricular ejection fraction of 35% or less undergoing coronary artery bypass grafting in off pump technique. Levosimendan was administered in 20 patients with a dosage of 0.2 mcg/kg/min 2h before surgery for 24h. We compared these patients with 20 patients undergoing same surgical procedure with low EF and treatment with dobutamine dosage of 200 mcg/min. Primary endpoint was improvement of cardiac index and ICU stay. Second endpoint was need of vasoconstrictors, ventilation time and mortality.

Results: 2015–2017 we enrolled 40 patients. 20 patients were in the levosimendan group, 3/20 received additional dobutamine and these were compared with the group of 20 patients receiving conventional therapy with dobutamine. For cardiac indices, the improvement of the levosimendan group was 1.78 ± 0.35 l/min/m² to 2.37 ± 042 l/min/m², which is statistical significant (p = 0.04). In the dobutamine group the arise was from 2.2 ± 0.63 to 2.33 ± 0.41 l/min/m², which is not significant (p = 0.65). Median ventilation time was 19.53h to 20.6h and equal. ICU stay was in levosimendan group 47.71h versus 65.5h in dobutamine group in median, which is significant longer. Need for vasoconstrictor were 32.11 ± 18.26 mcg/min for levosimendan group and 39.67 ± 27.6 mcg/min in dobutamine group. The increase of cardiac ischemic markers showed no significant difference in both groups. One patient died within 30 days caused by non-cardiac death.

Conclusions: Levosimendan showed a positive effect to the improvement of cardiac index without an elevated need for vasoconstrictors compared with the conventional therapy with dobutamine. Resulting in a significant reduction of ICU stay Levosimendan is therefore cost-effective. Benefit for long term survival and mortality remains unclear because of the small number of patients and the study design.