By univariate Cox regression analysis , NT-proBNP was found to be a powerful predictor of subsequent all-cause mortality ( relative risk [ RR ] , 2.7 ; 95 % CI , 1.7 to 4.3 ; P = 0.0001 for above versus below median ) and all-cause mortality or hospitalization for heart failure ( RR , 2.4 ; 95 % CI , 1.8 to 3.4 ; P = 0.0001 for above versus below median ) .
