Bivalirudin Angioplasty Trial (BAT)
In the BAT studies, patients with unstable angina undergoing PCI were randomized 1:1 to a 1 mg/kg bolus of bivalirudin and then 2.5 mg/kg/h for four hours and then 0.2 mg/kg/h for 14 to 20 hours or to 175 IU/kg bolus of heparin followed by an 18- to 24-hour infusion of 15 IU/kg/h infusion. Additional heparin but not bivalirudin could be administered for ACT less than 350 seconds. The studies were designed to demonstrate the superiority of bivalirudin to heparin on the occurrence of any of the following during hospitalization up to seven days of death, MI, abrupt closure of the dilated vessel, or clinical deterioration requiring revascularization or placement of an aortic balloon pump.
The 4312 subjects ranged in age from 29 to 90 (median 63) years. 68% were male, and 91% were Caucasian. Median weight was 80 kg (39 to 120 kg). 741 (17%) subjects had post-MI angina.
Twenty-three percent of patients were treated with heparin within one hour prior to randomization.
The studies did not demonstrate that bivalirudin was statistically superior to heparin for reducing the risk of death, MI, abrupt closure of the dilated vessel, or clinical deterioration requiring revascularization or placement of an aortic balloon pump, but the occurrence of these events was similar in both treatment groups. Study outcomes are shown in Table 2.
Table 2: Incidences of In-hospital Endpoints in BAT Trial
Endpoint
| Bivalirudin (n=2161)
| HEPARIN (n=2151)
|
Primary endpoint†
| 7.9%
| 9.3%
|
Death, MI, revascularization
| 6.2%
| 7.9%
|
Death
| 0.2%
| 0.2%
|
MI
| 3.3%
| 4.2%
|
† A composite of death or MI or clinical deterioration of cardiac origin requiring revascularization or placement of an aortic balloon pump or angiographic evidence of abrupt vessel closure
AT-BAT Trial (NCT# 00043940)
This was a single-arm open-label study in which 51 subjects with heparin-induced thrombocytopenia (HIT) or heparin induced thrombocytopenia and thrombosis syndrome (HITTS) undergoing PCI. The majority of patients achieved adequate ACT at the time of device activation and no major bleeding was reported. Two patients developed thrombocytopenia.