NPPB and heart failure: The primary endpoint of the trial was to assess the maximal OM concentration in plasma, and the secondary endpoints aimed to examine changes from baseline in various clinical parameters at week 20, including systolic ejection time, stroke volume, left ventricular end-systolic diameter, left ventricular end-diastolic diameter, heart rate, and NT-proBNP (i.e., a biomarker associated with the severity of heart failure), and the safety and tolerability of OM that were measured by the assessment of adverse events incidence from baseline to week 24.