The purpose of this study was to assess the effect of in-hospital initiation of sacubitril/valsartan (LCZ696) vs. enalapril on time averaged proportional change in NT-proBNP in patients who have been stabilized following hospitalization for acute decompensated heart failure (ADHF) and reduced ejection fraction (left ventricular ejection fraction (LVEF) ≤ 40%).