The rate of major adverse cardiovascular events was not significantly lower with bivalirudin than with heparin ( 10.3 % and 10.9 % , respectively ; relative risk , 0.94 ; 95 % confidence interval [ CI ] , 0.81 to 1.09 ; P = 0.44 ) , nor was the rate of net adverse clinical events ( 11.2 % and 12.4 % , respectively ; relative risk , 0.89 ; 95 % CI , 0.78 to 1.03 ; P = 0.12 ) .