The Asymptomatic Carotid Surgery Trial-2 (ACST-2): an ongoing randomised controlled trial comparing carotid endarterectomy with carotid artery stenting to prevent stroke
- 1 October 2017
- journal article
- research article
- Published by National Institute for Health and Care Research in Health Technology Assessment
- Vol. 21 (57), 1-40
- https://doi.org/10.3310/hta21570
Abstract
Background: A successful open surgical operation to remove atheromatous carotid artery narrowing that has not yet caused a stroke (asymptomatic carotid stenosis) carries some procedural risk but, if completed successfully, halves patients' future annual stroke risk for at least 10 years. A newer, less invasive alternative is carotid stenting, which also carries some procedural risk, especially if the carotid lesion has recently given rise to a stroke (symptomatic carotid stenosis). For both surgery and stenting, improvements in technique (and in medication) have reduced risk. Early studies showed that treating carotid narrowing by stenting, particularly for symptomatic lesions, caused more procedural minor strokes than surgery, but more recent trials in symptomatic and in asymptomatic patients found that both procedures might now be equally safe and effective. However, low patient numbers, short follow-up of the long-term effects on stroke rates and wide confidence intervals mean that worldwide uncertainty persists between carotid surgery and carotid stenting, and national and international guidelines remain unclear as to which is generally better. Objectives: The second Asymptomatic Carotid Surgery Trial (ACST-2) compares carotid endarterectomy (CEA) with carotid artery stenting (CAS) directly, randomising patients with asymptomatic carotid stenosis for whom a carotid procedure is considered definitely necessary; both procedures seem anatomically feasible, and there is substantial uncertainty as to which of the two would be better for such individuals. Although it will compare procedural risks, the trial's primary aim is to compare the long-term durability of protection against strokes occurring in the years post procedure due to any remaining or recurrent carotid disease. Design: Randomised controlled trial comparing CEA with CAS. Setting: Hospitals in the UK and worldwide, in which carotid procedures are common. Participants: Men and women with severely stenotic atherosclerotic carotid artery disease, with or without previous stroke but with no recent symptoms from the randomised artery. Interventions: CEA and CAS. Outcomes: (1) Periprocedural risk defined as myocardial infarction, stroke or death within 30 days after the randomised procedure and (2) long-term rates of disabling or fatal stroke during follow-up of patients. Measurement of costs and outcomes: Measurement of intervention costs and stroke costs (periprocedural and during follow-up) and of quality of life [EuroQol-5 Dimensions (EQ-5Dr)] for patients in the top six recruiting countries (UK, Italy, Belgium, Germany, Serbia and Sweden), who currently constitute 85% of those randomised. Progress so far: By the end of March 2016, ACST-2 had included 2125 patients, nearly two-thirds of the planned recruitment of 3600; 1061 were randomly allocated to CEA and 1064 to CAS. Conclusions: Further funding has been secured and recruitment continues, with completion anticipated by the end of 2019. ACST-2 will report initial results in 2021.Keywords
Funding Information
- Health Technology Assessment Programme (06/301/233)
- Bupa Foundation (BUPAF/33(a)/05)
This publication has 12 references indexed in Scilit:
- Ten-year risk of stroke in patients with previous cerebral infarction and the impact of carotid surgery in the Asymptomatic Carotid Surgery TrialInternational Journal of Stroke, 2016
- Long-Term Results of Stenting versus Endarterectomy for Carotid-Artery StenosisThe New England Journal of Medicine, 2016
- Long-term outcomes after stenting versus endarterectomy for treatment of symptomatic carotid stenosis: the International Carotid Stenting Study (ICSS) randomised trialThe Lancet, 2014
- Efficacy and safety of more intensive lowering of LDL cholesterol: a meta-analysis of data from 170 000 participants in 26 randomised trialsThe Lancet, 2010
- Carotid Artery Stenting: Relationship between Experience and Complication RateInternational Journal of Stroke, 2010
- 10-year stroke prevention after successful carotid endarterectomy for asymptomatic stenosis (ACST-1): a multicentre randomised trialThe Lancet, 2010
- Carotid artery stenting compared with endarterectomy in patients with symptomatic carotid stenosis (International Carotid Stenting Study): an interim analysis of a randomised controlled trialThe Lancet, 2010
- Thirty-Day Outcomes for Carotid Artery Stenting in 6320 Patients From 2 Prospective, Multicenter, High-Surgical-Risk RegistriesCirculation: Cardiovascular Interventions, 2009
- Atorvastatin Reduces the Risk of Cardiovascular Events in Patients With Carotid AtherosclerosisStroke, 2008
- MRC/BHF Heart Protection Study of cholesterol lowering with simvastatin in 20 536 high-risk individuals: a randomised placebocontrolled trialThe Lancet, 2002