The effects of levosimendan in cardiac surgery patients with poor left ventricular function.

Background: Patients with poor left ventricular function often require inotropic drug support immediately after cardiopulmonary bypass. Levosimendan improves cardiac function by a novel mechanism of action compared to currently available drugs. We hypothesized that, in patients with severely compromised ventricular function, the use of levosimendan would be associated with better postoperative cardiac function than with inotropic drugs that increase myocardial oxygen consumption.

Methods: Thirty patients with a preoperative ejection fraction < or =30% scheduled for elective cardiac surgery with cardiopulmonary bypass were randomized to two different inotropic protocols: milrinone 0.5 microg [corrected] x kg(-1) x min(-1) or levosimendan 0.1 microg [corrected] x kg(-1) x min(-1), started immediately after the release of the aortic crossclamp. The treatment was masked to the observers. All patients received dobutamine 5 microg [corrected] x kg(-1) x min(-1).

Results: Stroke volume was similar between groups initially after surgery, but it declined 12 h after surgery in the milrinone group but not in the levosimendan group (P < 0.05 between groups) despite similar filling pressures. Total dose, duration of inotropic drug administration and norepinephrine dose were lower in the levosimendan group than in the milrinone group (P < 0.05). The duration of tracheal intubation was shorter in the former group compared with the milrinone group (P = 0008). Three patients in the milrinone group but none in the levosimendan group died within 30 days of surgery.

Conclusion: In cardiac surgery patients with a low preoperative ejection fraction, stroke volume was better maintained with the combination of dobutamine with levosimendan than with the combination of dobutamine with milrinone.