A Comment on the use of Levosimendan for the Management of Right Ventricular Dysfunction in Patients Undergoing Mitral Valve Surgery

The management of patients with right heart dysfunction undergoing mitral valve surgery can be challenging, often requiring the use of various vasoactive agents. We would like to start by commending Bharathi et al.[1] on a paper in which they explore the effects of levosimendan on right ventricular function in this high-risk group of patients in a prospective, placebo-controlled study. While Bharathi et al. were able to demonstrate some promising results within their study, we would like to discuss a few points. Firstly, we noticed the relatively young age of the study population (placebo group mean age 39.6, levosimendan group mean age 46.03), which could potentially preclude the generalisation of the conclusions in older and more comorbid cohorts of patients. We would also like to comment on the use of the vasoactive inotropic score in the context of the study. While using a summative score helps with analysis, and it is commonly used in research, more detailed documentation of the magnitude and duration of the vasoactive drug therapy in the different study groups would have helped to identify more clearly the contribution of levosimendan.[2] A more standardised protocol for the use of vasoactive drugs in the study would have likely allowed for more reliable comparisons between the two groups. On the subject matter, more broadly, we take this opportunity to discuss the administration regime of a levosimendan infusion, an area of ongoing variability in practice and in clinical trials. Previous work in heart failure patients has suggested that while the clinical effects of levosimendan and its active metabolite may be seen within a few hours of the infusion starts, peak benefit may not occur until 1–3 days after the start of the infusion[3] and this effect might be even slower in the perioperative setting.[4] Regimes that investigated the effectiveness of levosimendan in cardiac surgery included initiation of an infusion the day before surgery, immediately after induction of anaesthesia, before placing the patient on CPB, or after the aortic clamp removal, with or without a loading dose.[4,5] This suggests that the ideal regime for the pre-emptive use of levosimendan in cardiac surgery for patients with pre-existing right heart failure needs further investigation. In summary, Levosimendan remains an effective inodilator with unique properties, although it has shown neutral effects on mortality compared to placebo in randomised trials on cardiac surgery patients (with possible benefit on isolated CABG cases with low ejection fraction).[5] Further prospective, multicentre, well-designed trials focusing on the effect of levosimendan on the outcome of patients with right heart dysfunction undergoing cardiac surgery would be very welcomed. We commend Bharathi et al. for their contribution towards this direction. Financial support and sponsor ship Nil. Conflicts of interest There are no conflicts of interest.