In a multivariate Cox regression analysis , change in NT-proBNP concentration during admission , change from discharge to 1month after discharge , and the absolute NT-proBNP concentration at 1 month after discharge were of independent prognostic value for both end points ( hazard ratios for HF readmission or mortality : 1.71 , 95 % confidence interval [ CI ] 1.13-2 .60 , Wald 6.4 [ P = .011 ] versus 2.71 , 95 % CI 1.76-4 .17 , Wald 20.5 [ P < .001 ] versus 1.81 , 95 % CI 1.13-2 .89 , Wald 6.1 [ P = .014 ] , respectively .