Selective Nonoperative and Delayed Management of Severe Asymptomatic Carotid Artery Stenosis

Abstract

Although intervention is generally the standard of care for severe (80-99%) asymptomatic carotid stenosis, conservative management may be appropriate for a subset of patients. Our goal was to assess reasons for and outcomes of nonoperative/delayed operative management of asymptomatic severe carotid stenosis. Institutional vascular laboratory data from 2010 to 2018 was queried for all patients who underwent a carotid duplex ultrasonography. Patients with severe asymptomatic carotid stenosis (80-99%) were included. Such stenosis was defined by an end diastolic velocity >140cm/sec on duplex ultrasound in patients without transient ischemic attacks (TIA)/strokes ≤6months prior to imaging. Nonoperative/delayed operative management was defined as not undergone carotid endarterectomy (CEA) or carotid artery stent (CAS) ≤6months after imaging. Reasons for nonoperative management or delayed intervention as well as subsequent TIA/stroke and survival were determined. Kaplan-Meier analysis was performed to evaluate survival. Among 211 patients with severe carotid stenosis, 35 (16.6%) were managed nonoperatively or with delayed operation. Mean age in this subset was 72.6±11.4years and the majority were female (57.1%), had a smoking history (74.3%), and were on statins (91.4%) at the time of index duplex ultrasound. Reasons for no/delayed intervention were classified as severe medical comorbidities (37.1%), advanced age (17.1%), no referral for intervention (14.3%), patient refusal (14.3%), other severe concomitant cerebrovascular disease (11.4%), and active/advanced cancer (5.7%). Over a median follow-up of 35.2months, no patients experienced TIAs/strokes attributable to carotid stenosis. One patient had a multifocal bilateral stroke after a cardiac arrest and prolonged resuscitation. A subset of patients underwent delayed CEA (8.6%) or CAS (2.9%). Four-year survival after initial imaging was 79%. Reasons for nonoperative and delayed operative management in our cohort of asymptomatic carotid stenosis were commonly due to comorbidities and advanced age. However, a subset of patients was never referred to vascular surgeons/interventionalists. Adverse neurologic events due to carotid stenosis were not observed during follow-up and patients had relatively high long-term survival.