Haemodynamic effects of levosimendan for low cardiac output after cardiac surgery: a case series.
BACKGROUND
Levosimendan is a new inotropic vasodilator for the treatment of decompensated heart failure. Compared to other inotropic agents, it has been shown to improve myocardial contractility without increasing oxygen requirements. However, experience with levosimendan in patients with low cardiac output after cardiopulmonary bypass is limited. In this case series we present the short-term haemodynamic effects of levosimendan added to dobutamine for the management of low cardiac output syndrome after cardiac surgery.


METHODS
Twelve patients with low cardiac output during the first 6 hours after completion of cardiopulmonary bypass, who were already receiving dobutamine at a mean dose of 6.7 microg/kg/min, were treated with levosimendan at a loading dose of 6 microg/kg, followed by a 24-hour infusion of 0.2 microg/kg/min. During a 24-hour observation period the following haemodynamic parameters were measured: arterial, central venous, pulmonary arterial and pulmonary capillary wedge pressure, heart rate, cardiac index, stroke volume, systemic and pulmonary vascular resistance, as well as mixed venous oxygen saturation, oxygen delivery and oxygen extraction ratio.


RESULTS
Levosimendan significantly improved cardiac index (from 2.1 +/- 0.1 L/min/m2 at baseline to 3.2 +/- 0.3 L/min/m2 at 24 hrs, p < 0.001) as well as mixed venous oxygen saturation, oxygen delivery and oxygen extraction ratio (p < 0.001) and caused a significant reduction in systemic and pulmonary vascular resistance (p < 0.001). At the same time, a significant decrease in central venous, pulmonary arterial and pulmonary capillary wedge pressure was noted (p < 0.001). These beneficial haemodynamic effects resulted in significantly decreased catecholamine requirements.


CONCLUSIONS
In this group of cardiac surgical patients with postoperative myocardial dysfunction resistant to dobutamine, levosimendan added to dobutamine was effective in reversing low cardiac output syndrome.
Malliotakis
Polychronis
P
Department of Cardiothoracic Surgery, Heraklion University Hospital, P.O. Box 1352, 71110 Heraklion, Crete, Greece. malliot@altecnet.gr
Xenikakis
Theophilos
T
Linardakis
Manolis
M
Hassoulas
John
J
D000318:Adrenergic beta-Agonists / Q000627:therapeutic use; D000368:Aged; D001794:Blood Pressure / Q000187:drug effects; D002303:Cardiac Output, Low / Q000188:drug therapy* / Q000209:etiology / Q000503:physiopathology*; D006348:Cardiac Surgical Procedures; D002315:Cardiopulmonary Bypass / Q000009:adverse effects; D002316:Cardiotonic Agents / Q000627:therapeutic use*; D002395:Catecholamines / Q000627:therapeutic use; D004280:Dobutamine / Q000627:therapeutic use; D004359:Drug Therapy, Combination; D005260:Female; D006115:Greece; D006331:Heart Diseases / Q000601:surgery; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006835:Hydrazones / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000187:drug effects; D010101:Oxygen Consumption / Q000187:drug effects; D011724:Pyridazines / Q000627:therapeutic use*; D012107:Research Design; D000077464:Simendan; D013318:Stroke Volume / Q000187:drug effects; D013997:Time Factors; D016896:Treatment Outcome; D014655:Vascular Resistance / Q000187:drug effects; D014665:Vasodilator Agents / Q000627:therapeutic use*
D000318:Adrenergic beta-Agonists; D002316:Cardiotonic Agents; D002395:Catecholamines; D006835:Hydrazones; D011724:Pyridazines; D014665:Vasodilator Agents; D000077464:Simendan; D004280:Dobutamine