Repetitive LevosimenDan infusions fOR patients with advanced chronic heart failure in the vulnerable post-discharge period: the multinational randomized LeoDOR trial

Abstract Background Studies of the repetitive use of intravenous levosimendan suggested a beneficial effect in patients with advanced heart failure (HF). It was the aim of the LeoDOR trial to test the efficacy and safety of intermittent levosimendan therapy in the vulnerable phase following a hospitalization for acute HF. Methods In this multicenter, double-blind, three-armed trial with an enrolment period from 3-2018 to 6-2021, patients with advanced HF were randomized 2:1 at the end of an index hospitalization for acute HF to intermittent levosimendan therapy or placebo for a period of 12 weeks. Levosimendan was administered according to center preference either as 6-hour infusion at a rate of 0.2 mcg/kg/min every 2 weeks, or as 24-hour infusion at a rate of 0.1 mcg/kg/min every 3 weeks. The primary efficacy assessment after 14 weeks was based on a global rank endpoint consisting of three hierarchical groups: Tier 1 = time to death or urgent heart transplantation or implantation of a ventricular assist device; Tier 2 = time to non-fatal HF requiring i.v. vasoactive therapy; Tier 3 = time-averaged proportional change in NTproBNP from baseline to week 14. Results Due to a forced interim interruption of the study as a result of the COVID-19 pandemic, the planned number of patients could not be recruited. The final modified intention-to-treat (mITT) analysis included 145 patients (93 in the combined levosimendan arm, 52 in the placebo arm). Patient characteristics were well balanced between treatment and placebo arms (mean age 69.3±9.7 vs 67.9±10.1, proportion of women 22.6% vs 21.2%, HF-hospitalizations in previous 12 months 1.9±1.4 vs. 1.7±1.1, NTproBNP at baseline 4740 ng/L (IQR 2235 – 9016) vs 5380 ng/L (IQR 2287 – 8204). There were no marked differences regarding HF medication and implanted devices. Compared with placebo, intermittent levosimendan had no significant effect on the primary endpoint (mean rank score 71.8 for the levosimendan group vs 75.1 for the placebo group; p = 0.65). However, there was a strong signal towards a higher incidence of the individual clinical components of the primary endpoint (tier 1 plus tier 2) in the levosimendan group vs the placebo group both after 14 weeks (HR 2.94, 95%CI 1.13–7.70; p = 0.028) and 26 weeks (HR 1.65 95%CI 0.87 – 3.12; p = 0.123). The number of investigator-reported adverse events during and immediately after drug application was 12.4% in the levosimendan group vs 11.8% in the placebo group (p = 0.905). Conclusion Our findings do not support the use of intermittent levosimendan to improve post-hospitalization clinical stability in patients who were recently hospitalized with HF and reduced LVEF. Further studies are warranted to find the correct use of levosimendan in advanced heart failure patients.