Protamine use in carotid endarterectomy has been shown to be associated with fewer perioperative bleeding complications without higher rates of thromboembolic events. However, the effect of protamine use on complications following transfemoral carotid artery stenting is unclear and concerns remain regarding thromboembolic events.
A retrospective review was performed for patients undergoing transfemoral carotid artery stenting in the Vascular Quality Initiative from March 2005 to December 2018. We assessed in-hospital outcomes using propensity-score-matched cohorts of patients who did and did not receive protamine. The primary outcome was in-hospital stroke or death. Secondary outcomes included bleeding complications, stroke, death, transient ischemic attack, myocardial infarction, and congestive heart failure exacerbation. Bleeding complications were categorized as bleeding resulting in intervention or in blood transfusions.
Of the 17,429 patients undergoing transfemoral carotid artery stenting, 2,697 (15%) patients received protamine. We created 2,300 propensity-matched pairs of patients who did and did not receive protamine. There were no statistically significant differences in stroke or death between the two cohorts (protamine 2.5% vs no protamine 2.9%, RR 0.85 [95%CI 0.60-1.21]; P = .37). Protamine use was not associated with statistically significant differences in perioperative bleeding complications resulting in interventional treatment (0.9% vs 0.5%, RR 2.10 [95%CI 0.99-4.46]; P = .05) or blood transfusion (1.2% vs 1.2%, RR 0.92 [95%CI 0.53-1.61]; P = .78). There were also no statistically significant differences for the individual outcomes of stroke (1.8% vs 2.3%, RR 0.78 [95%CI 0.52-1.16]; P = .22), death (0.9% vs 0.8%, RR 1.17 [95%CI 0.62-2.19]; P = .63), transient ischemic attack (1.4% vs 1.3%, RR 1.10 [95%CI 0.67-1.82]; P = .70), myocardial infarction (0.5% vs 0.4%, RR 1.20 [95%CI 0.52-2.78]; P = .67), or heart failure exacerbation (1.0% vs 0.9%, RR 1.05 [95%CI 0.58-1.90]; P = 0.88). Protamine use in patients presenting with symptomatic carotid stenosis was associated with lower risk of stroke or death (3.0% vs 4.3%; RR 0.69 [95%CI 0.47-0.998]; P = .048), whereas there were no statistically significant differences in stroke or death with protamine use in asymptomatic patients (1.6% vs 1.0%; RR 1.63 [95%CI 0.67-3.92]; P = .28).
Heparin-reversal with protamine following transfemoral carotid artery stenting is not associated with an increased risk of thromboembolic events and its use in symptomatic carotid disease is associated with a lower risk of stroke or death.
Copyright © 2020. Published by Elsevier Inc.