Safety and complications associated with the use of protamine in percutaneous coronary intervention.

Objectives: There is a paucity of data on the use of protamine after PCI. The purpose of this study was to assess the incidence of thrombotic complications of protamine after high-risk PCI.

Methods: The authors conducted a retrospective analysis of 168 patients. All patients received protamine intra- or immediately post-index PCI. Baseline characteristics and procedural characteristics including heparin dosing, protamine dosing, and bleeding and thrombotic complications were evaluated. The primary outcome was the incidence of acute stent thrombosis (ST), subacute ST, and 'other' thrombotic complications. Secondary outcomes included mortality within 24 hours and within 30 days of the index procedure.

Results: A total of 168 patients were included. The majority of patients received dual anti-platelet therapy prior to the index procedure (85%). The average procedure time was 202 ± 103 minutes, and an average of 2.59 (± 1.38) stents were deployed. An average protamine dose of 32mg was administered, and the median dose was 20mg (IQR 20). Seventy-three (43%) had a coronary perforation and five (3%) had access site related bleeding requiring transfusion. Four (2%) patients had acute ST, no patients experienced subacute ST, and 2 (1%) patients developed non-coronary arterial thrombosis. Eight (5%) died within 24 hours of their PCI and 14 (8%) patients died within 30 days after PCI.

Conclusions: In our cohort, administration of protamine was well tolerated in the majority of patients, however, 3.6% of patients did experience coronary or peripheral arterial thrombosis warranting caution when using protamine in these challenging scenarios.