In non-LBBB patients with a prolonged PR interval , CRT-D treatment was associated with a 73 % reduction in the risk of heart failure/death ( hazard ratio , 0.27 ; 95 % confidence interval , 0.13-0 .57 ; P < 0.001 ) and 81 % decrease in the risk of all-cause mortality ( hazard ratio , 0.19 ; 95 % confidence interval , 0.13-0 .57 ; P < 0.001 ) compared with implantable cardioverter defibrillator therapy .