Short-term Risk of Recurrent Stroke in Symptomatic Carotid Near-Occlusion

Reconstruction note. Reconstructed on October 14, 2026 for the missed October 12 publication slot. This is a replacement article, not a recovered original. The paper was selected in verified PMC look-back mode; it was not recovered as that day's original briefing article.

Clinical Question (PICO)

Among patients with symptomatic carotid near-occlusion (CNO), is full distal internal carotid artery (ICA) collapse, compared with CNO without full collapse, associated with ipsilateral ischaemic stroke or retinal infarction before revascularisation over 90 days—and especially in the first 48 hours?1 The pooled cohort analysis also explored whether transient ischaemic attack (TIA) at presentation identifies a higher-risk subgroup; that subgroup analysis was not prespecified.1

Bottom Line

In 360 patients, the pooled 90-day recurrent-stroke risk was 16.4% (95% CI 11.7%–21.1%), including 5.9% (95% CI 3.4%–8.3%) in the first two days.1 Full collapse was associated with higher adjusted 0–2-day recurrence hazards under both definitions, but the cohorts were observational and heterogeneous: these estimates describe prognosis, not proof that urgent carotid revascularisation prevents stroke.1

Design

Study type: Individual-patient-data pooled analysis of three prospective observational cohorts (TACNOS, UCC, and CAOS); not randomized.1
N: 360 symptomatic CNO cases: TACNOS 101, UCC 118, CAOS 141.1 Full-collapse appearance was available for 333; measurement criteria for 219.1
Setting and years: Two Swedish cohorts and a multicentre Spanish registry; cohort recruitment periods were 2010–2014, 2018–2022, and 2010–2016, respectively.1
Follow-up: Primary risk horizon 90 days; median observed follow-up 25 days (IQR 9–90), varying by cohort.1
Analysis: Kaplan–Meier and Cox regression; revascularisation, death, loss to follow-up, and 90 days were censoring events.1 Prespecified sensitivity analyses addressed ascertainment bias and compared appearance-based definitions in the same TACNOS/UCC population as the measurement analysis.1
Primary outcome: Recurrent ipsilateral ischaemic stroke or retinal infarction within 90 days of the presenting event, counting only events before revascularisation.1

Population

Inclusion criteria. Symptomatic CNO diagnosed using NASCET or equivalent criteria centered on reduced distal ICA calibre; the contributing cohort studies needed at least 20 CNO cases, an index time tied to the presenting event, and full-collapse data.1 CNO diagnosis was based on severe stenosis plus distal ICA reduction assessed in absolute and relative terms—not percent grading alone.1

Exclusion criteria. Studies relying solely on ultrasound were excluded; the paper notes that CNO can occur across ultrasound velocity ranges.1 The report does not provide one uniform patient-level exclusion list across the three source cohorts.1

Baseline characteristics. Mean age was 71 (SD 9) years; 87/360 (24%) were women.1 Presenting events were stroke in 189 (53%), TIA in 104 (29%), and retinal events in 67 (19%).1 Cohorts differed materially in baseline profile and timing: median time from presentation to angiography was 4 days in TACNOS, 2 in UCC, and 12 in CAOS.1

Interventions

There was no assigned treatment comparison.1 Medical prevention was initiated as early as possible and generally included antiplatelet therapy and statins, with blood-pressure and diabetes treatment as needed.1 Exact medication data were unavailable; usual therapy was single antiplatelet treatment, while dual antiplatelet treatment was mainly used with carotid stenting and became more common without stenting in later study years.1

Outcomes

The study's pooled cumulative risks and adjusted Cox estimates are observational; CNO with full collapse is not interchangeable with conventional 70%–99% stenosis or complete ICA occlusion.1

Analysis	Result
All patients, 90 days	46/360 recurrent strokes; 16.4% (95% CI 11.7%–21.1%).
All patients, 0–2 days	21 events; 5.9% (95% CI 3.4%–8.3%).
Between-cohort risk	At 90 days: TACNOS 23.9% (15.6%–35.5%); UCC 22.3% (13.7%–35.1%); CAOS 8.1% (4.2%–15.2%); I²=77.4%, P=.012. At 0–2 days: 11.9% (6.9%–20.0%), 6.1% (2.9%–12.3%), and 1.4% (0.4%–5.6%), respectively; I²=77.3%, Q=8.80, P=.012.
Full collapse by appearance, 90 days (n=333)	18.7% (11.1%–26.3%) vs 17.4% (10.5%–24.3%) without collapse; adjusted HR 1.5 (0.8–2.9), P=.19.
Full collapse by measurement, 90 days (n=219)	29.0% (17.6%–40.4%) vs 23.1% (12.5%–33.7%); adjusted HR 2.0 (1.0–3.9), P=.04. Measurement data came only from TACNOS and UCC.
Full collapse, 0–2 days	Appearance: 12.3% (6.0%–18.3%) vs 3.1% (0.7%–5.5%), adjusted HR 4.0 (1.5–10.5), P=.005. Measurement: 20.1% (10.3%–29.9%) vs 4.0% (0.9%–7.1%), adjusted HR 4.8 (1.8–12.8), P=.002.
Full collapse plus TIA at presentation, 90 days	37.8% (95% CI 19.2%–56.4%) by appearance; 50.4% (26.1%–74.6%) by measurement. Exploratory, non-prespecified subgroup; most recurrences occurred in the first two days. Subgroup denominators are not given in the main text.
Days 3–90	Neither full-collapse definition was significantly associated with recurrent stroke in this interval.

The estimates above use each analysis's available denominator and the study's pre-revascularisation event definition.1

Figures

Graphical abstract summarizing the pooled cohorts, full-collapse definitions, and early recurrent-stroke risks in symptomatic carotid near-occlusion. — *Graphical abstract.* Overview of the three-cohort analysis, full-collapse assessment, and observed early recurrence findings.[1](#fn-source-1)

Coronal CTA examples compare a left carotid near-occlusion with full distal ICA collapse and one without full collapse. — *Figure 1.* Coronal CTA examples show distal ICA calibre in near-occlusion with and without full collapse.[1](#fn-source-1)

Kaplan–Meier plots of 90-day recurrence by full-collapse definition and by the combination of collapse with TIA presentation. — *Figure 2.* Kaplan–Meier estimates compare 90-day recurrence by collapse status, with additional panels stratifying by TIA at presentation.[1](#fn-source-1)

Forest plots show 90-day recurrent-stroke hazard estimates across subgroups by visual and measured full-collapse status. — *Figure 3.* Forest plots display 90-day recurrent-stroke estimates across subgroups under the two full-collapse definitions.[1](#fn-source-1)

Criticisms

Internal: Between-cohort heterogeneity was substantial (I²=77.4% at 90 days).1 The CAOS cohort's later diagnostic angiography (median 12 days) could miss patients who recurred before diagnosis, plausibly lowering observed ultra-early risk; the authors say this survivor bias cannot be fully corrected.1
Censoring and selection: 53% underwent revascularisation within 90 days, so censoring may be informative.1 In the prespecified ascertainment-bias analysis, the no-collapse 90-day risk fell from 17.4% to 10.8%; the Aalen–Johansen analysis also lowered this group's estimate to 11.1% from a naive 17.4%.1 Detailed full-collapse cumulative-incidence estimates are reported in the online supplement, which is not included in the assigned local source bundle, so they are not reproduced here.[1] Measurement-based analysis included only 219 TACNOS/UCC patients, not all three cohorts.1
Causal limits: Nonrandomized cohorts cannot establish whether early revascularisation improves outcomes or is safe.1 No patient with full collapse underwent CEA/CAS within 48 hours for secondary prevention in these cohorts, apart from three UCC stents performed as part of thrombectomy for the presenting event.1
External review: No independent editorial or letter was retrieved; this appraisal uses the primary report only.

Funding

The authors report no funding and no conflicts of interest (“Nothing to report”).1

The paper

Authors. Andrés García-Pastor and Elias Johansson.
Title. Short-term risk of recurrent stroke in symptomatic carotid near-occlusion: pooled analysis of three cohort studies.
Journal. European Stroke Journal. 2026;11(8):aakag100.
DOI. 10.1093/esj/aakag100
PMCID. PMC13502401
License. Creative Commons Attribution 4.0 International (CC BY 4.0); original figures are attributed to the authors and publication.1
Source [1]. Europe PMC full-text XML.

Deep Dive — click to expand

What this is

Pooling TACNOS, UCC, and CAOS, this prognostic analysis tests whether full distal ICA collapse marks very early recurrence in symptomatic CNO.1 It estimates risk before revascularisation; it does not test a procedure.1

1. Shadow Audit

The 90-day cohort estimates ranged from 8.1% to 23.9% (I²=77.4%).1 Appearance-defined collapse was not significant at 90 days, but adjusted early HRs were 4.0 and 4.8 by appearance and measurement.1 Measurement covered 219 patients; TIA-plus-collapse was exploratory.1

2. Inversion Engine

A procedure would need to reach patients before much of the 0–2-day risk accrues without offsetting procedural harm.1 These cohorts supply neither a treatment effect nor a benefit threshold; the authors note that many events would require intervention within hours.1 A prospective trial with standardized imaging and time zero is the missing test.1

3. Second-Order Catalyst

Editorial inference, not tested: can a thread-like distal ICA be recognized and reviewed quickly enough to make a very-early-treatment trial feasible?1 Diagnostic confusion with complete occlusion and technical difficulty are barriers, not proof that routine urgent revascularisation works.1 The data motivate study, not adoption.1

4. Asymmetric Leverage

The measured full-collapse group had a 20.1% 0–2-day risk versus 4.0% without collapse, but this comparison covered 219 patients and has wide confidence limits.1 The leverage is identifying and validating a specific phenotype—not treating all severe stenosis alike.1

5. Paradigm Destroyer

The paper challenges treating all near-occlusions as one prognostic category.1 CNO is defined by distal ICA calibre reduction; it is neither conventional 70%–99% NASCET stenosis nor complete occlusion.1 The justified update is better classification and trial design, not a blanket urgent-procedure order.1

MVP — Minimum Viable Proof

Full collapse was associated with higher 0–2-day recurrence under both definitions: adjusted HR 4.0 by appearance and 4.8 by measurement.1 These observational estimates (20 and 19 early events, respectively) call for prospective testing of feasibility and net benefit.1

Best Combination

In the common TACNOS/UCC population, appearance- and measurement-based early estimates were concordant.1 Prespecified sensitivity analyses also retained the early pattern while lowering some 90-day estimates.1 This supports an association, not a causal revascularisation benefit.1

Overvalue Warning

Do not treat the exploratory 37.8%–50.4% TIA-plus-collapse risks as individual predictions or proof of procedural benefit.1 Do not apply conventional 70%–99% stenosis rules to CNO: near-occlusion is not complete ICA occlusion, and classification depends on distal-vessel imaging.1

Educational use notice. The Time Is Brain Review is dedicated to medical education. Figures from published articles are embedded for teaching purposes, with attribution to the original publication. We do not claim copyright over any embedded figure; all rights remain with the original publisher and authors under the article's published license. If you are a rights holder and would like a figure removed, please contact the editorial team. See our editorial notice for the full policy.