At week @ , the combination-therapy group had greater reductions from baseline in N-terminal pro-brain natriuretic peptide levels than did the pooled-monotherapy group ( mean change , -@ % vs. -@ % ; P < @ ) , as well as a higher percentage of patients with a satisfactory clinical response ( @ % vs. @ % ; odds ratio , @ -LSB- @ % CI , @ to @ -RSB- ; P = @ ) and a greater improvement in the @-minute walk distance ( median change from baseline , @ m vs. @ m ; P < @ ) .