Indian Journal of Vascular and Endovascular Surgery

: 2021  |  Volume : 8  |  Issue : 3  |  Page : 197--198

Asymptomatic carotid stenosis: Are we under treating?

Edwin Stephen 
 Department Vascular Surgery, Sultan Qaboos University Hospital, Muscat, Oman

Correspondence Address:
Edwin Stephen
Department Vascular Surgery, Sultan Qaboos University Hospital, Muscat

How to cite this article:
Stephen E. Asymptomatic carotid stenosis: Are we under treating?.Indian J Vasc Endovasc Surg 2021;8:197-198

How to cite this URL:
Stephen E. Asymptomatic carotid stenosis: Are we under treating?. Indian J Vasc Endovasc Surg [serial online] 2021 [cited 2023 Jan 27 ];8:197-198
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The pandemic led to extensive spread of knowledge and skill through various webinars, CMEs, online workshops, etc., Unlike conferences, participation has been across the calendar year with a wider reach than before. Some of the “hot topics” are asymptomatic carotid stenosis (ACS) artery disease, ruptured aortic aneurysm management, thrombosis in COVID-19 patients, use of intravascular ultrasound, venous stenting, etc.

Carotid artery disease has been a topic of debate since 1950s and remains so. Guidelines from different societies and practice in the management of ACS with carotid endarterectomy (CEA) or carotid artery stenting (CAS) differ widely. There is, however, an increase in the number of CEA/CAS where there is a “fee for service.“[1],[2]

My personal preference has been not to intervene in ACS and along came a webinar, in early 2021, on the topic held by the VEITH Symposium.[1] Below are some of the statements from the webinar.

“A comparison of current best medical therapy versus carotid intervention (CEA/CAS) is urgently needed” Dr. Ali F. AbuRahma.

“The available evidence base demonstrates that, currently, all people with asymptomatic stenosis should be treated with medical intervention alone.” Dr. Anne L. Abbott.

“The pronouncement that many “high-quality” clinical studies document the low stroke risk of ACS is nonsense or, worse yet, deliberate distortion of published data.” Dr. Richard P. Cambria.

At the end of the webinar, I felt “guilty as charged” for not offering intervention and adequate follow-up for patients under my care with ACS. I was excited about this “emerging evidence” and tried to convince my colleagues that we need to do more!

In April, in an expert comment by Mr. Ross Naylor, “Asymptomatic Carotid Stenosis” Less is more![3] got me to revisit findings from the Asymptomatic Carotid Atherosclerosis Study (ACAS) and Asymptomatic Carotid Surgery Trial (ACST) trials, look at new evidence and conduct an online survey about management of ACS among colleagues in the Vascular Society of India (VSI).

Mr. Naylor puts it across simply, as this – for an absolute risk reduction 5.9% for ACAS and 5.4% for ACST, 941 patients in the former and 946 in the later trail, would unnecessarily have undergone a CEA. This is in the context of number of strokes prevented at 5 years/1000 CEAs.[3] CREST-2 might answer the question “Are we overtreating?“

Dr. Cambria says that considering ACS to be a benign disease is a “self-serving myth.” While there have been improvements in best medical therapy (BMT), real-world issues such as patient tolerance to medication and compliance effect clinical outcomes.[1] Studies by his team have shown that BMT does not prevent plaque progression in patients with moderate ACS (50%–69%) despite the low-density lipoprotein level being <100 mg/dl.[4] In another study involving 126 carotid arteries in 115 patients with ACS (severe stenosis), 80% of whom were on BMT, the ipsilateral neurological event rate was 25% at 5 years. The risk was higher in patients with preocclusive lesions.[5]

The ESVS/ESC laid out certain “high-risk factors” in their guidelines such as stenosis progression >20%, prior contralateral transient ischemic attack, intraplaque hemorrhage, and plaque lucency, etc., If a patient with ACS had a single HRF and a 50%–99% stenosis, the risk of a stroke was 4.3/100 patient-years versus 0.9/100 patient-years if no HRF. If the stenosis was 70%–99% with an HRF, then the stroke risk was 7.3/100 patient-years versus 1.7/100 if no HRF is present. The 85 authors of the guideline recommend CEA/CAS in patients with 60%–99% stenosis, life expectancy of more than 5 years, favorable anatomy plus one or more HRF. Mr. Naylor says and I quote “Retention of the “one size fits all” approach to managing ACS (offering CEA/CAS to most patients) is unsustainable, both fiscally, and on the basis of evidence.“[1],[3],[5],[6]

In a study involving 400 centers in the USA, Europe, Australia, and New Zealand which included 58,607 procedures; 18% were octogenarians; 36% women – the variation for CAS within centers was highest in the USA and Australia (0%–80%). Countries with “fee for service” had higher treatment rates for ACS than those with population base reimbursement, although the association was not significant. The authors conclude that number of patients with ACS, treatment options offered to them, management of women, and octogenarians varies considerably within and between countries.[2]

The Lancet Neurology published a prospective population-based cohort study, systematic review, and meta-analysis studying the risk of stroke in ACS earlier this year. The 5-year ipsilateral stroke risk was higher in patients with stenosis of 70%–99% versus those with 50%–69% stenosis, 6 of 53 patients versus zero of 154 patients, respectively. They conclude that CEA has a beneficial role in severe ACS; however, benefit of revascularization in the 50%–69% stenosis over BMT is questionable.[7]

In an online survey that I conducted among the vascular fraternity in VSI about management of ACS, 127 surgeons responded, 80% of these consultants. 50.8% (64) said they would not intervene. About 77.8%, of the remaining would intervene if stenosis was 70%–99% while patient was on BMT, and if there was contralateral occlusion (66.4%) or an ulcerated soft plaque (33.6%). About 65 (51.6%) would intervene in octogenarians and 97 (76.4%) said gender did not make a difference to treatment offered. About 54.3% said that they would offer intervention if a patient was to undergo a coronary artery bypass graft and had a high-grade ACS. The majority (82.1%) would offer CEA and 17.9% CAS for ACS. These findings compare with findings from other studies.[2],[8]

What about screening patients with ACS? The US Preventive Services Task Force has reiterated its 2014 recommendation against screening for ACS in the adult population. There is no benefit and possible harm, the committee said.[9]

The future of CAS in ACS seems to be heading the way of transcarotid artery revascularization as it is thought to be superior to transfemoral CAS.[10] The other field that is developing is in formulating a risk score that will assess the development of ACS and estimate the prevalence of the same while predicting those at high risk of a neurological event.[11],[12] A third area requiring clarity is the role of intervention in patients undergoing CABG and having ACS. The coronary artery bypass graft surgery in patients with ACS-CABACS trial recruited 129 patients from the Czech Republic and Germany, whose ultrasound by ECST criteria were detected to have at least 80% stenosis. The trial was prematurely stopped for a lack of funding. The isolated CABG group did better than those who underwent a combined procedure although not statistically significant. The stroke/death rates, at 30 days and 1 year, were 18.5% and 23.4% in the combined group versus 9.7% and 13.1% in the isolated CABG group.[13] Dr. Rebecca Gottesman, Associate Editor for Neurology states in her editorial that when it comes to management of ACS in patients requiring CABG, it may be “that less is more.“[14]

This article, I hope has arched a few eyebrows and raised a few questions. The Indian vascular surgery fraternity has a varied approach to ACS. Perhaps, once the ESVS publishes new guidelines in 2022, we too should work on drawing out guidelines for the management of carotid artery disease that suit the Indian patient, our health-care system, and his/her wallet.


I wish to thank every member of the VSI who participated in the ACS online survey.


1Available from: [Last accessed on 2021 Feb 20].
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