Net adverse clinical events at 30 days occurred in 65 patients ( 8.8 % ) of 735 who were treated with bivalirudin compared with 96 patients ( 13.2 % ) of 729 treated with heparin ( relative risk [ RR ] , 0.67 ; 95 % CI , 0.50-0 .90 ; difference , -4.3 % , 95 % CI , -7.5 % to -1.1 % ; P = .008 ) ; and 124 patients ( 17.0 % ) of 730 treated with heparin plus tirofiban ( RR for bivalirudin vs heparin plus tirofiban , 0.52 ; 95 % CI , 0.39-0 .69 ; difference , -8.1 % , 95 % CI , -11.6 % to -4.7 % ; P < .001 ) .