Levosimendan enhances cardiac performance after cardiopulmonary bypass: A prospective, randomized placebo-controlled trial

Levosimendan is a new myofilament calcium (Ca2+) sensitizer that increases myocardial contractility by stabilizing the Ca2+-bound conformation of trop onin C. We tested the hypothesis that levosimendan enhances cardiac perform ance after cardiopulmonary bypass (CPB). Anesthesia was induced and maintai ned with midazolam, sufentanil, and vecuronium in 18 patients randomly assi gned to receive levosimendan (18 or 36 mu g/kg loading dose and 0.2 or 0.3 mu g/kg/min infusion, respectively) or placebo 15 min before and continued for 6 h after CPB. Significant (p < 0.05) increases in heart rate (HR) and decreases in systemic vascular resistance (SVR) occurred 15 min after CPB i n patients receiving placebo. Later increases in mean arterial pressure (MA P) and cardiac output (CO) and decreases in stroke volume (SV) and pulmonar y vascular resistance also were observed. HR was greater in patients receiv ing high- but not low-dose levosimendan versus placebo immediately after CP B. MAP also was lower in patients treated with either dose of levosimendan compared with placebo after CPB. Levosimendan increased CO and decreased SV R (4.2 +/- 0.4 to 7.9 +/- 0.4 L/min and 1,150 +/- 99 to 512 +/- 42 dyn/s/cm (5), respectively, 15 min after CPB; mean +/- SEM). CO and SV were higher a nd SVR was lower in patients receiving levosimendan versus placebo after CP B. No differences in arterial oxygenation and perioperative arrhythmias (Ho lter analysis) were observed between groups. The results indicate that levo simendan enhances cardiac performance after CPB in humans.