This study compared the efficacy and safety of sacubitril/valsartan to enalapril in Black and non-Black Americans with acute decompensated heart failure (ADHF).Black patients have a different response to treatment with angiotensin-converting enzyme inhibitors compared with other racial and ethnic groups. How Black patients with ADHF respond to sacubitril/valsartan, an angiotensin receptor-neprilysin inhibitor, is unclear. PIONEER-HF was a double-blind randomized clinical trial of sacubitril/valsartan versus enalapril in hospitalized patients with ADHF following hemodynamic stabilization.In a pre-specified subgroup analysis, we examined changes in N-terminal pro-B-type natriuretic peptide, clinical outcomes, and safety according to race.The study population, all enrolled in the United States, included 316 (36%) Black participants, 515 (58%) White participants, and 50 (5.7%) participants of other racial groups. The reduction in N-terminal pro-B-type natriuretic peptide concentration at weeks 4 and 8 was significantly greater with sacubitril/valsartan than enalapril in both Black (ratio of change with sacubitril/valsartan vs. enalapril: 0.71; 95% confidence interval [CI]: 0.58 to 0.88) and non-Black patients (ratio of change: 0.71; 95% CI: 0.61 to 0.83; interaction p = 1.00). Compared with enalapril, sacubitril/valsartan also reduced the pre-specified exploratory composite of cardiovascular death or HF rehospitalization in both Black (hazard ratio: 0.47; 95% CI: 0.24 to 0.93) and non-Black patients (hazard ratio: 0.65; 95% CI: 0.40 to 1.06; interaction p = 0.44).Among Black patients admitted with ADHF in the United States, the in-hospital initiation of sacubitril/valsartan was more effective than enalapril in reducing natriuretic peptide levels and the composite of cardiovascular death or HF rehospitalization. The effect of sacubitril/valsartan did not differ by race. (Comparison of Sacubitril/Valsartan Versus Enalapril on Effect on NT-proBNP in Patients Stabilized From an Acute Heart Failure Episode [PIONEER-HF]; NCT02554890).