Abstract
Interventional cardiology procedures require full anticoagulation to prevent thrombus
formation on catheters and devices with potential development of embolic complications.
Bivalirudin, a short half-life direct thrombin inhibitor, has been largely used during
percutaneous coronary interventions and represents the preferred alternative to heparin
in patients with heparin-induced thrombocytopenia (HIT). However, few data are available
about intraprocedural use of bivalirudin during transcatheter structural heart disease
interventions. Activated clotting time (ACT) monitoring during bivalirudin infusion
presents some limitations and it is not mandatory. We report a case of bivalirudin
use in a patient with type-2 HIT during percutaneous mitral valve repair with the
Mitraclip system (Abbott, Abbott Park, Illinois, United States). Despite use of standard
bivalirudin dose (0.75 mg/kg bolus and 1.4 mg/kg/min infusion—reduced infusion rate
was motivated by a glomerular filtration rate of 37 mL/min), the patient developed
a large thrombus on the second clip during its orientation toward the mitral orifice.
ACT was measured at that time and was suboptimal (240 seconds). The case was successfully
managed with clip and thrombus retrieval, adjunctive 0.3 mg/kg bivalirudin bolus and
increased infusion rate, and clip repositioning with ACT monitoring. This report makes
the case for mandatory ACT checking and drug titration during high-risk catheter–based
structural heart disease interventions, even when thromboprophylaxis is performed
with bivalirudin. Additional coagulation tests may be useful to monitor bivalirudin
response in similar cases.
Keywords
Thrombosis - heart - antithrombin
