Efficacy and safety of protamine sulfate following carotid artery stenting

protamine sulfate is used to reduce bleeding risk after Carotid Artery Stenting (CAS), but its efficacy in personalized patient settings remains underexplored. This study aims to identify factors associated with greater benefits from protamine sulfate following CAS.

A retrospective review of Vascular Quality Initiative (VQI) data (2016-2022) identified patients undergoing CAS, divided into Transfemoral CAS (TF-CAS) and Transcarotid artery revascularization (TCAR) groups. Multivariate analysis used to identify perioperative predictors of bleeding complications, and propensity score matching compared rates of death and thrombotic events (myocardial infarction (MI), stroke/transient ischemic attack (TIA)) between protamine and no protamine groups.

Among 51,473 patients (36.9 % females), 56.4 % underwent TCAR (Protamine: 85.6 %; No protamine: 14.4 %), and 43.6 % underwent TF-CAS (Protamine: 18.9 %; No protamine: 81.1 %). Protamine significantly reduced bleeding complications in female patients and those on ACE inhibitors in both groups. In the TF-CAS group, protamine was associated with lower all-cause mortality (7.9 % vs. 11.5 %; P < .001) without an increase in MI (0.5 % vs. 0.9 %) or stroke/TIA (2.8 % vs. 2.9 %; P > .05). In the TCAR group, protamine had similar rates of all-cause mortality (7.7 % vs. 7.3 %), MI (0.4 % vs. 0.3 %), and stroke/TIA (2.4 % vs. 2.9 %; P > .05).

Protamine sulfate appears to be effective in reducing the bleeding complications in TCAR patients without increasing death or thrombotic complications. Its benefits are especially notable in females and those on ACE inhibitors, regardless of the CAS approach. Although protamine use in the TF-CAS cohort was associated with reduced all-cause mortality, it did not show an overall benefit in bleeding reduction. However, in TF-CAS, females and patients on ACE inhibitors did appear to benefit, supporting a more selective approach to its use.