New study data suggest that the interventional treatment of symptomatic carotid artery disease may result in an improved rate of age-adjusted overall survival compared to medical management. However, the same study—presented at this year’s European Society for Vascular Surgery (ESVS) annual meeting (24–27 September, Kraków, Poland)—also indicates a relatively low future ipsilateral stroke risk among patients who were not offered carotid intervention, highlighting medical management’s importance as a standalone strategy in patients deemed to be ‘high risk’ if treated via intervention.
Findings from the study in question were delivered by Eric T A Lim (Waikato Hospital, Hamilton, New Zealand), on behalf of Manar Khashram (Waikato Hospital, Hamilton, New Zealand) and other investigators, in an abstract presentation at ESVS 2024.
“There is Level 1 evidence around the management of symptomatic carotid artery stenosis, with superiority of intervention compared to medical therapy for stroke prevention,” Lim and colleagues state in their abstract. “While, long term, the efficacy of carotid intervention has been clearly documented, the natural history on symptomatic patients with ipsilateral carotid stenosis has not been well described in the contemporary era—when best medical therapy has evolved. With an ageing population and increase in frailty, information on medical management alone should be discussed with patients to assist in clinical decision-making.”
On this basis, Lim et al’s prospective, observational study—undertaken in a single vascular tertiary referral centre in New Zealand—aimed to assess the outcomes of symptomatic carotid artery stenosis cases that were managed non-operatively. The study was carried out from June 2019 to January 2024, with all symptomatic carotid artery disease referrals at the centre being included, but cases with no carotid imaging or in which the patient subsequently underwent carotid surgery within six weeks of referral being excluded. Lim and colleagues performed Kaplan-Meier analyses to assess ipsilateral stroke-free and age-adjusted Cox proportional hazard models, and ultimately determine all-cause survival.
During the study period, a total of 280 patients were referred with symptomatic carotid disease. The majority of these patients (63.7%) underwent carotid endarterectomy (CEA), while 1.3% underwent carotid artery stenting (CAS) and 35% were managed medically. In the 84 patients managed medically—or ‘conservatively’—the median age was 73.6 years. Lim et al found that the three most common reasons for selecting conservative management were the patient being below the threshold for the consideration of intervention (43.2%); internal carotid artery (ICA) occlusion/near occlusion (25%); and poor neurological recovery post-stroke (11.4%).
Out of the 10 patients with poor neurological recovery post-stroke, only two went on to receive a delayed carotid intervention, the investigators report. However, there were five patients (6%) who developed a further ipsilateral stroke or transient ischaemic attack (TIA) following conservative management during the follow-up period. The majority of patients (65.5%) were commonly managed with dual antiplatelet therapy (DAPT) and statins, Lim et al relay.
According to the investigators, patients who underwent carotid intervention had a 0.25 (0.17–0.5) hazard ratio of survival compared to patients managed conservatively—when adjusted for age. The overall survival rates at one and four years were 88% and 57%, respectively, and corresponding ipsilateral stroke-free survival rates at both one and four years were 97% in the medically managed patient group.
“These data support [the finding] that patients who were not offered intervention for symptomatic carotid artery disease, and were managed medically, had lower age-adjusted overall survival compared to patients undergoing carotid intervention,” Lim and colleagues conclude. “However, the risk of future ipsilateral stroke was relatively low compared to the landmark trials, highlighting the importance of medical therapy as a standalone strategy for those patients deemed high risk for carotid intervention. Further, larger cohorts are warranted to assess the long-term outcomes comparing surgical intervention to nonoperative management in symptomatic carotid artery disease.”
