In order to bring you the best possible user experience, this site uses Javascript. If you are seeing this message, it is likely that the Javascript option in your browser is disabled. For optimal viewing of this site, please ensure that Javascript is enabled for your browser.
Did you know that your browser is out of date? To get the best experience using our website we recommend that you upgrade to a newer version. Learn more.

Carotid artery surgery and stenting have similar long-term effects on stroke

ACST-2 trial presented in a Hot Line Session today at ESC Congress 2021

Interventional Cardiology and Cardiovascular Surgery

Sophia Antipolis, France – 29 Aug 2021:  Carotid artery surgery and stenting have comparable long-term effects on fatal or disabling stroke in asymptomatic patients with severe carotid artery stenosis. That’s the finding of late breaking research presented in a Hot Line session today at ESC Congress 20211 and published simultaneously in The Lancet.

Patients with severe carotid artery stenosis are at elevated risk of stroke and both carotid artery stenting (CAS) and carotid artery surgery, also called carotid endarterectomy (CEA), can restore patency and reduce the long-term risk of stroke. Nationwide registry data from Germany have shown among asymptomatic patients, CAS and CEA are both associated with an approximately 1% risk of disabling stroke or death.2 Comparative data are lacking on the long-term protective effects of the two procedures.

ACST-2 was the largest trial to compare the long-term effect of CAS versus CEA on stroke in asymptomatic patients with a severely narrowed carotid artery that had not yet caused a stroke. The trial enrolled patients with severe carotid artery narrowing (60% or more reduction in diameter on ultrasound) found by chance, but with no recent stroke or other neurological symptoms. Participants were thought by their doctor to need CAS or CEA but both doctor and patient were substantially uncertain about which procedure was preferable.

A total of 3,625 patients were enrolled from 130 centres in 33 countries. Participants were randomly allocated 1:1 to CAS or CEA and followed up for an average of five years. The main outcomes were: 1) procedural risks (morbidity and mortality within one month after the procedure); and, most importantly, 2) non-procedural stroke, subdivided by severity.

Regarding procedural risks, 1% of patients in both groups had a disabling stroke or died within 30 days (15 allocated to CAS and 18 to CEA) and 2% had a non-disabling procedural stroke (48 allocated to CAS and 29 to CEA).

The main outcome was five-year non-procedural stroke; fatal or disabling stroke occurred in 2.5% of patients in each group, for a rate ratio (RR) of CAS versus CEA of 0.98 (95% confidence interval [CI] 0.64–1.48; p=0.91), and any non-procedural stroke occurred in 5.3% of the CAS group versus 4.5% of the CEA group (RR 1.16; 95% CI 0.86–1.57; p=0.33). A meta-analysis of this and all other major trials of CAS versus CEA yielded a similarly non-significant result for any stroke (RR 1.11; 95% CI 0.91–1.32; p=0.21).

Principal investigator Professor Alison Halliday of the University of Oxford, UK said: “We have shown that, for patients with a severely narrowed carotid artery, stenting and surgery have similar effects on the chances of having a disabling or fatal stroke. The risk from each procedure is about 1%. After that, however, the annual risk over the next five or more years is halved, from 1% down to 0.5% per year.”



Notes to editor

ESC Press Office
Tel: +33 (0) 7 8531 2036

Follow us on Twitter @ESCardioNews 

The hashtag for ESC Congress 2021 is #ESCCongress.

This press release accompanies both a presentation and an ESC press conference at ESC Congress 2021. It does not necessarily reflect the opinion of the European Society of Cardiology.

Funding: ACST-2 is currently funded from the core support from the Medical Research Council (MRC), the British Heart Foundation, and Cancer Research UK for the University of Oxford’s NDPH. The trial had grants from the BUPA Foundation (BUPAF/33a/05) and National Institute for Health Research Health Technology Assessment programme (HTA06/301/233) until 2013.

Disclosures: None.

References and notes

1 Second asymptomatic carotid surgery trial (ACST-2): a randomised comparison of carotid artery stenting versus carotid endarterectomy. (online 29 August 2021 in The Lancet)

2 Institut für Qualitätssicherung und Transparenz im Gesundheitswesen (IQTiG). Karotis-Revaskularisation. https://iqtig. org/qs-verfahren/qs-karotis

About the European Society of Cardiology

The ESC brings together health care professionals from more than 150 countries, working to advance cardiovascular medicine and help people to live longer, healthier lives.

About ESC Congress 2021 - The Digital Experience

It is the world’s largest gathering of cardiovascular professionals, disseminating ground-breaking science in a new digital format. Online each day – from 27 to 30 August. Explore the scientific programme. More information is available from the ESC Press Office at