Modifiable risk factors for occurrence of ipsilateral ischemic events after carotid endarterectomy beyond perioperative period

Abstract

ObjectiveThe purpose of this study was to quantify the effects of several modifiable variables on the occurrence of stroke after the initial perioperative period for patients who had undergone carotid endarterectomy (CEA). MethodsThe primary outcome for the present study was the development of an ischemic stroke or transient ischemic attack (TIA) in the cerebral hemisphere ipsilateral to CEA after the initial hospitalization. All CEAs in the VQI between January 2003 and May 2022 were queried. We identified 171,816 CEAs in the database. The exclusion criteria for the study were the lack of follow-up data for >30 days, concomitant coronary artery bypass surgery, concomitant proximal or distal carotid intervention at CEA, other arterial interventions at CEA, and stroke or TIA during the initial hospital admission, leaving 126,290 patients for analysis. We used the χ2 test for statistical analysis of the outcome of ipsilateral ischemic stroke or TIA after the initial CEA hospital admission to determine the relevant variables. Age was evaluated as an ordinal variable using the Student t test. Variables with P ≤ .05 on univariable analysis were included in the multivariable Cox regression time-to-event analysis for the primary outcome. Kaplan-Meier curves were constructed of the most significant variables on Cox regression as a visual aid. ResultsThe following variables achieved significance on Cox regression for an association with development of ipsilateral hemispheric ischemic events after the index CEA hospital admission: lack of patch placement at CEA site (hazard ratio [HR], 18.24; P < .0001), lack of antiplatelet therapy at long-term follow-up (LTFU; HR, 9.75; P < .0001), lack of statin therapy at LTFU (HR, 3.18; P < .001), lack of statin therapy at hospital discharge (HR, 1.25; P = .015), anticoagulation at LTFU (HR, 1.53; P < .001), development of >70% recurrent stenosis (HR, 2.15; P < .001), and shunt use at surgery (HR, 1.20; P = .007). Patients with patch placement at surgery and patients with confirmed antiplatelet therapy at LTFU had had 99.8% and 99.6% freedom from an ischemic event ipsilateral to the side of the CEA at LTFU, respectively. This finding is in contrast to the 5.7% and 4.7% positivity for ischemic events for those without patch placement at surgery and those not receiving antiplatelet therapy at LTFU, respectively (P < .0001 for both). ConclusionsPerformance of patch angioplasty arterial closure was remarkably protective against ipsilateral cerebral ischemic events at LTFU after CEA. Discharging and maintaining patients with antiplatelet and statin medication after CEA significantly reduces the incidence of future ipsilateral ischemic events. Thus, a significant opportunity exists for enhanced outcomes with improved implementation of these measures.