Average annual ipsilateral stroke rates in relation to advanced carotid stenosis in the identified studies were low relative to likely routine practice procedural risks, and opportunities exist to improve noninvasive arterial care quality using current evidence-based approaches.
Key Findings
Results
Only five studies published since 2013 met quality criteria for assessing ipsilateral stroke rates with noninvasive care alone in patients with advanced carotid stenosis.
Search criteria required studies to be principally prospective with >100 patients stratified by symptomatic status and followed for ≥12 months
Four studies satisfied criteria for asymptomatic carotid stenosis (two randomized and two nonrandomized)
Only one study satisfied criteria for symptomatic carotid stenosis, and it was nonrandomized
Studies were published since 2013 and involved advanced (50% to 99%) carotid stenosis
Results
The average annual rate of ipsilateral stroke in asymptomatic carotid stenosis patients receiving noninvasive care alone ranged from 0.47% to 1.24%.
This range was derived from raw data across four qualifying studies
Studies included both randomized and nonrandomized designs
All patients had advanced (50% to 99%) carotid stenosis
These rates were described as low relative to likely routine practice procedural risks
Results
The average annual rate of ipsilateral stroke in symptomatic carotid stenosis patients receiving noninvasive care alone was 3.00% in the single qualifying study.
This figure came from a single nonrandomized study, limiting generalizability
The symptomatic rate of 3.00% was substantially higher than the asymptomatic range of 0.47% to 1.24%
Only one study met inclusion criteria for symptomatic patients, highlighting a major gap in the literature
Patients had advanced (50% to 99%) carotid stenosis
Results
In all five qualifying studies, noninvasive care was poorly described despite opportunities for improvement using current evidence-based approaches.
The authors assessed quality of noninvasive care using a novel scoring system called 'BRAINIAC'
Authors also used their own analyses on how to best define and manage stroke risk factors
Despite low stroke rates, gaps in care quality were identified across all studies
The authors anticipate that outcomes will improve further with noninvasive arterial care alone as quality improves
Conclusions
The current priority identified by the authors is to properly define and administer current best practice noninvasive arterial care and produce quality studies of its effectiveness in different populations.
The scarcity of qualifying studies (only five total) underscores the need for more rigorous research
The authors developed a novel 'BRAINIAC' scoring system to assess quality of noninvasive care
The authors call for prospective studies with >100 patients stratified by symptomatic status and followed for ≥12 months
Authors anticipate further outcome improvements with optimized noninvasive arterial care
What This Means
This research systematically reviewed studies published since 2013 to determine how often strokes occur on the same side as a significant carotid artery narrowing (50–99% blockage) when patients are treated with non-surgical, non-procedural methods alone — such as medications and lifestyle changes. The researchers found very few high-quality studies on this topic: only four for patients without prior stroke symptoms and one for patients with prior symptoms. Among patients without symptoms, the annual stroke risk ranged from about 0.47% to 1.24%, while the single study of symptomatic patients showed a higher annual rate of 3.00%. Importantly, these rates were considered low compared to the risks associated with surgical or procedural interventions commonly performed in routine clinical practice.
The researchers also evaluated how well the non-invasive treatments were described and carried out in these studies, using a scoring tool they developed called 'BRAINIAC.' They found that in all five studies, the quality and description of non-invasive care was lacking, and there were clear opportunities to do better using currently available evidence-based strategies for managing stroke risk factors.
This research suggests that non-invasive management of carotid artery narrowing may produce low stroke rates, potentially comparable to or better than procedural interventions when accounting for procedure-related risks. However, the very small number of qualifying studies reveals a significant gap in medical knowledge. The authors emphasize that standardizing and improving the quality of non-invasive care — and conducting more rigorous studies to evaluate it — should be an immediate priority, with the expectation that stroke outcomes could improve even further as care quality is optimized.
Abbott A, Lurie F, Budinčević H. (2026). Risk of stroke in noninvasively treated asymptomatic and symptomatic patients with carotid stenosis.. Seminars in vascular surgery. https://doi.org/10.1053/j.semvascsurg.2026.07.009