At 1 year , the rates of death of any cause ( 17.4 % vs. 12.8 % ; relative risk [ RR ] : 1.35 ; 95 % confidence interval [ CI ] : 0.73 to 2.50 ; p = 0.37 ) and of cardiovascular causes ( 12.4 % vs. 9.4 % ; RR : 1.32 ; 95 % CI : 0.63 to 2.75 ; p = 0.54 ) were not statistically significantly different in the balloon - and self-expandable groups , respectively .