Comparison of Levosimendan, Milrinone and Dobutamine in treating Low Cardiac Output Syndrome Following Valve Replacement Surgeries with Cardiopulmonary Bypass.

INTRODUCTION: Low Cardiac Output Syndrome (LCOS) following Cardiopulmonary Bypass (CPB) is common and associated with increased mortality. Maintenance of adequate cardiac output is one of the primary objectives in management of such patients.

AIM: To compare Levosimendan, Milrinone and Dobutamine for the treatment of LCOS after CPB in patients who underwent valve replacement surgeries.

MATERIALS AND METHODS: Sixty eligible patients meeting LCOS were allocated into three treatment groups: Group A-Levosimendan (loading dose 10μg/kg over 10 minutes, followed by 0.1μg/kg/min); Group B-Milrinone (loading dose 50 mcg/kg over 10 minutes followed by 0.5mcg/kg/min) and Group C-Dobutamine @ 5μg/kg/min to achieve target cardiac index (CI) of > 2.5 L/min/m2 . In case of failure, other drugs were added as required. Hemodynamic parameters were monitored using EV1000TM clinical platform till 30 minutes post CPB. INSTAT software was used for statistics and p<0.05 was considered significant.

RESULTS: The mean±standard deviation of time taken by Dobutamine, Levosimendan and Milrinone to bring the CI to target were 11.1±8.79, 11.3±6.34 and 16.62±9.33 minutes respectively (p=0.064). Levosimendan was equally effective in increasing and maintaining adequate CI as compared to Dobutamine (p>0.05). Levosimendan and Milrinone increased MAP (Mean Arterial Pressure) equally while Dobutamine was more effective as compared to both Levosimendan and Milrinone 20th minute onwards (p<0.01). Milrinone was less effective in increasing the stroke volume as compared to Dobutamine and Levosimendan while Dobutamine and Levosimendan were equally effective. There was no difference in the HR (Heart Rate) achieved with all these three drugs.

CONCLUSION: Levosimendan is equally effective to Dobutamine and better than Milrinone for the treatment of LCOS following CPB in patients undergoing valve replacement surgeries.