Levosimendan enhances cardiac performance in patients following cardiac surgery and cardiopulmonary bypass

This randomised, double-blind, placebo-controlled trial tested the effect of the calcium sensitiser levosimendan (LS) on cardiac performance in patients (n = 18) following cardiopulmonary bypass (CPB) and cardiac surgery.

Patients with normal preoperative left ventricular function received either placebo or 'low-dose LS' (18 μg/kg loading dose followed by 0.2 μg/kg/min) or 'high-dose LS' (36 μg/kg loading dose followed by 0.3 μg/kg/min) infusions, starting 15 min prior to separation from CPB (n = 6 per group). Treatments were continued for 6 hours. Haemodynamic and cardiac output (CO) measurements were recorded at baseline and following separation from CPB in all groups.

LS significantly (P < 0.05) increased CO (from 4.2 to 7.9 l/min) (high-dose) and similarly decreased systemic vascular resistance (from 1150 to 512 dyn/s/cm⁵; P < 0.05). Arterial and pulmonary artery pressures were significantly reduced by LS. Heart rate was not significantly changed, but stroke volume increased with LS. No differences in arterial oxygenation and perioperative arrhythmias (Holter) were seen between groups.

In conclusion, this study suggests that LS enhances cardiac performance in patients with normal preoperative cardiac function following CPB. The 'low-dose LS' demonstrated equivalent efficacy with the 'high-dose' group but had the advantage of not increasing vasoactive drug requirements.