Intraprocedural Thrombotic Events during Percutaneous Coronary Intervention Due to Acquired Antithrombin Deficiency-related Heparin Resistance Successfully Treated with Antithrombin Gamma Supplementation

A 75-year-old man receiving treatment for necrotizing pancreatitis developed septic disseminated intravascular coagulation and acute coronary syndrome (ACS). During percutaneous coronary intervention (PCI), a large amount of fresh thrombi appeared after balloon dilatation for the ACS-culprit lesion. Given the low plasma antithrombin (AT) activity and poorly prolonged activated clotting time (ACT), we suspected that acquired AT deficiency-related heparin resistance (HR) was responsible for the thrombus formation. Administration of AT gamma markedly improved ACT, and we successfully completed PCI. We suggest that AT gamma be considered a treatment option for AT deficiency-related HR and subsequent intraprocedural thrombotic events.