Objective: Levosimendan (LS) is a novel inodilator for the treatment of severe congestive heart failure (CHF). In this study, we investigated the potential long-term effects of intermittent LS treatment on the pathophysiology of heart failure.
Methods: Thirteen patients with modest to severe CHF received three 24-h intravenous infusions of LS at 3-week intervals. Exercise capacity was determined by bicycle ergospirometry, well-being assessed by Minnesota Living with Heart Failure Questionnaire (MLHFQ) and laboratory parameters of interest measured before and after each treatment.
Results: One patient experienced non-sustained periods of ventricular tachycardia (VT) during the first infusion and had to discontinue the study. Otherwise the LS infusions were well tolerated. Exercise capacity (VO2max) did not improve significantly during the study although symptoms decreased (P < 0.0001). Levels of plasma NT-proANP, NT-proBNP and NT-proXNP decreased 30-50% during each infusion (P < 0.001 for all), but the changes disappeared within 3 weeks. Although norepinephrine (NE) appeared to increase during the first treatment (P = 0.019), no long-term changes were observed.
Conclusion: Intermittent LS treatments decreased effectively and repetitively plasma vasoactive peptide levels, but no carryover effects were observed. Patients' symptoms decreased for the whole study period although there was no objective improvement of their exercise capacity. The prognostic significance of these effects needs to be further studied.