With a mean follow-up of 3.3 years , the primary outcome occurred in 320 of 1722 patients in the spironolactone group ( 18.6 % ) and 351 of 1723 patients in the placebo group ( 20.4 % ) ( hazard ratio , 0.89 ; 95 % confidence interval [ CI ] , 0.77 to 1.04 ; P = 0.14 ) .