Modifiable Risk Factors for the Occurrence of Ipsilateral Ischemic Events After Carotid Endarterectomy Beyond the Perioperative Period

The purpose of this study is to quantify the impact of several modifiable variables on the occurrence of stroke after the initial perioperative period for patients who have undergone carotid endarterectomy. The primary outcome for this study was the development of an ischemic stroke or transient ischemic event (TIA) in the cerebral hemisphere ipsilateral to carotid endarterectomy after initial procedural hospitalization. All carotid endarterectomies in the Vascular Quality Initiative between January 2003 and May 2022 were queried. We identified 171,816 carotid endarterectomies (CEA) in the database. Exclusion criteria included lack of follow-up beyond 30 days, concomitant coronary artery bypass surgery, concomitant proximal or distal carotid intervention at the time of CEA, other arterial intervention at the time of CEA, and stroke or TIA at the time of initial procedural hospital admission leaving 126,290 meeting inclusion. The first step in statistical analysis was χ2 testing for the outcome of ipsilateral ischemic stroke or TIA after initial CEA procedural hospital admission for relevant variables. Age was evaluated using the Student t-test. Variables with a P value of .05 or less on univariate analysis were then used for multivariable Cox regression time-to-event analysis for the primary outcome. Kaplan-Meier curves were constructed for the most significant variables. The following variables achieved significance on Cox regression for association with the development of ipsilateral hemispheric ischemic events after index CEA hospital admission over time: lack of patch placement at endarterectomy site (hazard ratio [HR]: 18.24, P < .0001), lack of antiplatelet therapy at the time of long-term follow-up (HR: 9.75, P < .0001), lack of statin at the time of long-term follow-up (HR: 3.18, P < .001), lack of statin at the time of hospital discharge (HR: 1.25, P = .015), anticoagulation at the time of long-term follow-up (HR: 1.53, P < .001), development of greater than 70% recurrent stenosis (HR: 2.15, P < .001), and shunt use at surgery (HR: 1.20, P = .007). Patients with placement of patch at the time of surgery and with confirmed antiplatelet therapy at the time of long-term follow-up had 99.8% and 99.6% respective freedom from the ischemic event ipsilateral to the side of their CEA in long-term follow-up. This stands in opposition to 5.7% positivity for the ischemic event for those without patch at surgery and 4.7% in those not on antiplatelet in long-term follow-up (P < .0001 for both). Freedom from event curves can be seen in Figs 1 and 2. The performance of patch angioplasty arterial closure is remarkably protective against ipsilateral cerebral ischemic events in the years after CEA. Discharging and maintaining patients on antiplatelet and statin medications after CEA significantly reduces future ipsilateral ischemic events. There is a significant opportunity for enhanced outcomes with improved implementation of these measures.Fig 2Impact of lack of antiplatelet in long-term follow-up on freedom from the ipsilateral ischemic event after carotid endarterectomy index hospital admission.View Large Image Figure ViewerDownload Hi-res image Download (PPT)