The anticoagulant therapy with bivalirudin to assist in the performance of percutaneous coronary intervention in patients with heparin-induced thrombocytopenia (ATBAT) study: main results.

Up to 5% of patients given heparin develop heparin-induced thrombocytopenia (HIT). These patients may need anticoagulation for acute coronary syndromes (ACS) or percutaneous coronary intervention (PCI), a clinical challenge given the limited alternatives. In a prospective, open-label study, we evaluated the safety and efficacy of bivalirudin in patients with HIT or HIT with thrombotic syndrome (HITTS) undergoing PCI. Patients aged 18 years were enrolled in 24 centers in 2 countries. Bivalirudin was given 5 minutes before PCI (1 mg/kg bolus; 2.5 mg/kg/hour infusion for 4 hours [high-dose group] or 0.75 mg/kg bolus; 1.75 mg/kg/hour infusion [low-dose group]). Clinical and hematological measures were assessed within 24 hours after starting bivalirudin, just before PCI, just before sheath removal, and 48 hours after treatment or at discharge, whichever occurred first. The primary endpoint was major bleeding 48 hours after discontinuation or until discharge, whichever occurred first. From July 1999 to February 2003, 52 patients were recruited. Procedural success (TIMI grade 3 flow and < 50% stenosis) was achieved in 98% of patients, and clinical success (absence of death, emergency bypass surgery, or Q-wave infarction) was achieved in 96%. One high-dose patient who underwent elective bypass surgery had major bleeding (1.9%; 95% CI: 0.05 10.65%), and 7 patients had minor bleeding. No patient had significant thrombocytopenia (platelet count < 50 109/L) after treatment. One patient in the low-dose group died from cardiac arrest ~46 hours after uncomplicated PCI. Bivalirudin appeared safe and provided effective anticoagulation during PCI. These data, and extensive experience with bivalirudin in PCI, support its use in high-risk patients with HIT requiring PCI.