Contralateral Occlusion and Concomitant Procedures Drive Risk of Non-ipsilateral Stroke After Carotid Endarterectomy

Abstract

Stroke after carotid endarterectomy (CEA) has been assessed widely. However, factors enhancing non-ipsilateral stroke risk are poorly defined. The aim of this study was to identify drivers of 30 day non-ipsilateral stroke after CEA in the Vascular Quality Initiative (VQI) and assess long-term survival based on laterality of post-operative stroke. The VQI was queried between April 1, 2003, and March 31, 2017, for all CEA. Bilateral carotid procedures within 30 days were excluded. Thirty day non-ipsilateral strokes were identified. Factors were examined to discriminate between patients with and without non-ipsilateral stroke. Univariable analysis followed by multivariable logistic regression was performed. Kaplan–Meier and log rank methods were used to estimate and compare survival. During this 14 year period, 80,230 CEA in 74,928 patients met the criteria. The average age was 70.3 ± 9.3 years. Most were male (48,506; 60%), Caucasian (73,967; 92%), smokers (60,543; 76%), and asymptomatic (43,074; 54%). Contralateral stenosis ≥70% was present in 8033 (10%) with 2239 (3%) having contralateral occlusion. In 491 (0.6%) patients, peri-operative non-ipsilateral stroke occurred. After characterising univariable associations, logistic regression identified independent drivers of non-ipsilateral stroke after CEA. Operative urgency (p = .001), symptomatic disease (p < .001) and contralateral occlusion (p = .001) were pre-operative drivers. Operative predictors included shunt use (p = .008), CEA with cardiac surgery (p = .013), and CEA with concomitant proximal ipsilateral endovascular intervention (p = .01). Use of dextran (p = .005) and anti-angiotensin therapy (p = .03) were protective. Reperfusion syndrome (p < .001), re-exploration (p < .001), myocardial infarction (p < .001), and intravenous treatment of hypotension (p < .001) or hypertension (p < .001) were post-operative correlates. Non-ipsilateral stroke 30 day mortality was less than ipsilateral stroke (6.1% vs. 10.3%; p = .007). Five year survival after non-ipsilateral stroke was 73%, and no different from ipsilateral stroke 76% (p = .16). Both were worse than without stroke (88%; p < .001). Non-ipsilateral stroke after CEA is rare. Features driving risk surround global disease burden, combined procedures, and haemodynamic fluctuations. Contralateral occlusion independently increases non-ipsilateral stroke risk. Regardless of laterality or location, effects of stroke after CEA on long-term survival are similar.