Some patients with carotid stenosis can be treated with medical therapy alone for stroke prevention and will gain no additional benefit from revascularisation. This is according to two-year interim results of multi-centre randomised trial.
Carotid endarterectomy or stenting was usually offered to patients with carotid stenosis to prevent stroke, but the guidance was based on randomised trials conducted more than 30 years ago, an international research team wrote in The Lancet Neurology.
Given improvements in medical therapy, the researchers wanted to assess whether patients with asymptomatic or symptomatic carotid stenosis with a predicted low to intermediate predicted stroke risk gained any additional benefit from revascularisation if they were receiving optimal medical therapy (OMT).
Patients were eligible for inclusion in the European Carotid Surgery Trial (ECST-2) if they were aged 18 years and older and had atherosclerotic carotid stenosis of 50% or greater with or without symptoms.
Symptomatic patients were required to have a predicted five-year risk of stroke of less than 20% based on the Carotid Artery Risk (CAR) score – a risk model which accounts for factors such as percentage of narrowing in the carotid artery and medical history, including diabetes.
The CAR score was recalibrated from an earlier carotid surgery trial and tested for the first time in this study, researchers explained.
OMT vs OMT plus revascularisation for carotid stenosis
A total of 429 patients with a median age of 72 years were enrolled across 30 centres in the UK, Europe and Canada and randomly assigned 1:1 to either OMT alone or OMT plus revascularisation.
OMT included a low cholesterol diet, target-adjusted cholesterol-lowering medication, antihypertensive therapy, antithrombotic therapy and regular checks to adjust the medication as necessary.
The primary outcome for this two-year interim analysis of the five-year trial was a hierarchical outcome composite of:
- periprocedural death, fatal stroke, or fatal myocardial infarction
- Non-fatal stroke
- Non-fatal myocardial infarction
- New silent cerebral infarction on imaging.
However, researchers found no evidence for benefit of revascularisation in addition to OMT in the first two years following the procedure.
Individualised carotid stenosis treatment via the CAR score
The findings provided an important step towards more individualised treatment in patients with carotid stenosis enabled by the CAR score, they said.
‘Our results indicate that this CAR score reliably predicted patients at low risk of stroke, with a two-year risk of ipsilateral stroke in the OMT alone group of only 2.9% compared with 6.2% in the OMT plus revascularisation group,’ they added.
They stressed, however, that the findings only applied to the group of patients with low or intermediate risk symptomatic stenosis selected using the CAR score, and to asymptomatic patients.
‘Identifying patients with carotid stenosis who are at high risk of future stroke, who might benefit from revascularisation, should also be a goal of future research,’ they concluded.
Senior author Professor Martin Brown, emeritus professor of stroke medicine at UCL Queen Square Institute of Neurology in London, said that while further follow-up is needed, his research team recommend using the CAR score to identify patients who could be managed with OMT alone.
‘This approach emphasises personal assessment and intensive treatment of vascular risk factors, potentially sparing many patients from the discomfort and risks of carotid surgery or stenting,’ he said.
‘Additionally, this method could lead to substantial cost savings for health services.’
Treating risk factors for stroke
The National Institute for Health and Care Research (NIHR), the Stroke Association and the Leeds Neurology Foundation funded the research in the UK, and the Swiss National Science Foundation and the Dutch Organisation for Knowledge and Innovation in Health, Healthcare and Well-Being funded the study in Europe.
Dr Louise Flanagan, head of research at the Stroke Association, said surgery or stenting could lead to complications including an increased risk of stroke, and other unpleasant side effects.
‘The CAR risk score offers the opportunity to take away the downsides of surgery and stenting by using medical therapy alone, as well as combining medical therapy with surgery,’ she said.
‘The medical therapies used to reduce the risk of stroke from atherosclerosis work by treating risk factors for stroke, including high cholesterol and raised blood pressure, which we are putting at the heart of our recommendations for the Government’s 10 Year Health Plan.’
Last year, research suggested that paediatric cholesterol tests and the adoption of an ‘adolescent cholesterol passport’ could help prevent up to one-fifth of premature heart disease. It found that elevated levels of cholesterol and dyslipidaemia in children and adolescents increased the risk of heart issues such as subclinical atherosclerosis in their mid-20s and premature death by their mid-40s.
