There were no statistically significant differences between treatments in the 30-day rates of major adverse cardiac or cerebral events ( 5.0 % for bivalirudin , 5.8 % for heparin , and 4.9 % for heparin plus tirofiban , P = .74 ) , stent thrombosis ( 0.6 % vs 0.9 % vs 0.7 % , respectively , P = .77 ) , acquired thrombocytopenia ( 0.1 % vs 0.7 % vs 1.1 % ; P = .07 ) , or in acute ( < 24-hour ) stent thrombosis ( 0.3 % in each group ) .