Data collection Baseline information was obtained in stable patients without signs of fluid overload or low-cardiac output after written informed consent. These data included medical history, hospitalizations, relevant clinical and demographic information and physical examination by means of direct interview, examination and medical record review and included NYHA class, most recent LVEF, medical therapy and 12-lead ECG. These data, including the occurrence of adverse events and hospitalizations was re-evaluated every two weeks the first 3 months and every 4 weeks the next 3 months. Additional evaluations at baseline included self-assessment of patient reported outcomes (PRO, including health-related quality of life-HR-QoL- evaluated by means of the generic EQ-5D and the HF specific Kansas City Cardiomyopathy Questionnaire, KCCQ), local laboratory measurements, and the distance walked in the 6 minutes walking test (6MWT). PRO and 6 MWT were re-evaluated at week 13 and week 25. Vital status assessment was also performed after 12 months of inclusion into the study. Measurements of serum amino-terminal B-type pro-natriuretic peptide (NT-proBNP, pg/mL) were performed locally with and immunoassay based on chemiluminescence using the Elecsys System (Roche®) before and 24 h after initiation of each study drug infusion (either Levosimendan or placebo).