'Bail-out' bivalirudin use in patients with thrombotic complications unresponsive to conventional treatment during percutaneous coronary intervention.

Percutaneous coronary intervention (PCI) is routinely performed in patients with non-ST elevation acute coronary syndromes after pretreatment with clopidogrel and periprocedural administration of unfractionated heparin on a weight-adjusted basis. Although activated clotting time (ACT) monitoring is encouraged to verify the adequacy of anticoagulation during the procedures, this is not a common practice in many laboratories. The authors describe 4 cases of patients with bifurcation lesions involving the left anterior descending coronary artery, who developed periprocedural thrombosis with acute transmural ischemia. All patients had inadequate ACT measurements, despite conventional heparin dosage and ongoing clopidogrel treatment. In order to achieve complete anticoagulation, patients were switched to bivalirudin, which determined a prompt effect on measured ACT. This therapeutic regimen, coupled with further intervention, allowed resolution of the thrombotic complication without bleeding. This report suggests the feasibility of a strategy of bivalirudin use in patients who have some degree of heparin 'resistance' in the setting of complicated PCI.