Timing and Outcomes of Intracranial Stenting in the Post-SAMMPRIS Era: A Systematic Review

Impact of qualifying artery on the efficacy of stenting plus medical therapy versus medical therapy alone in patients with symptomatic intracranial stenosis: a post-hoc analysis of the CASSISS trial

BACKGROUND

A recent trial failed to show any benefit of stenting plus medical therapy over medical therapy alone in patients with symptomatic intracranial stenosis. We aimed to examine whether the symptomatic qualifying artery modifies the effect of stenting plus medical therapy.

METHODS

This is a post-hoc analysis of the CASSISS trial that included patients with symptomatic intracranial stenosis, randomly assigned to undergo stenting plus medical therapy or medical therapy alone; 358/380 patients were included. Multivariable logistic regression analysis was used with an interaction term to estimate the altered treatment effect by the qualifying artery. The primary outcome was a composite of stroke or death within 30 days or stroke in the qualifying artery territory beyond 30 days through 1 year. The five secondary outcomes included stroke or death related to the qualifying artery territory at 2 and 3 years.

RESULTS

No significant treatment allocation-by-stenosis site interaction was observed (Pinteraction=0.435). Compared with medical therapy alone, the adjusted ORs for stenting plus medical therapy were 2.73 (95% CI 0.42 to 17.65) for internal carotid artery stenosis, 1.20 (95% CI 0.29 to 4.99) for M1 stenosis, 0.23 (95% CI 0.02 to 2.31) for vertebral artery stenosis, and 1.33 (95% CI 0.34 to 5.28) for basilar artery stenosis. Of the five secondary outcomes, none showed a significant treatment allocation-by-stenosis site interaction including stroke in the qualifying artery territory at 2 years (Pinteraction=0.659) and 3 years (Pinteraction=0.493).

CONCLUSIONS

Among patients with transient ischemic attacks or ischemic stroke due to severe intracranial atherosclerotic stenosis, there was no evidence that the symptomatic qualifying artery could determine the addition of stenting to medical therapy.

Comparing the Impact of Stenting vs. Medical Therapy for Intracranial Arterial Stenosis : A Systematic Review and One-stage and Two-stage Meta-Analysis of Randomized Clinical Trials

PURPOSE

In the treatment of intracranial arterial stenosis (ICAS), controversies remain regarding the optimal treatment strategy. Our study aims to conduct an individual patient-level data meta-analysis of existing RCTs comparing PTAS versus best medical therapy and to identify differences in outcomes such as incidence of ischemic stroke or death.

METHODS

Randomised controlled trials comparing the outcomes of stenting versus best medical therapy for patients who had symptomatic ICAS of >50%. Excluded studies included case reports, case series, reviews, observational studies,  letters or studies evaluating isolated angioplasty techniques without stenting. Data was extracted in accordance with PRISMA guidelines.

RESULTS

7 studies involving 1425 participants were included. There was an increased risk in the incidence of stroke and death within the first 30 days post-procedure for patients treated with PTAS over best medical therapy (RR = 2.22 [1.28-3.86], I² = 0%). Patients who underwent stenting also had a significantly higher risk of intracranial haemorrhage (RR = 12.66 [2.41-66.45], I² = 0%) and death (RR = 5.41 [1.20-24.28], I² = 0%).Under the shared frailty model, stenting when compared to medical therapy has a HR of 1.81 (95% CI:1.25-2.6) of stroke or death across 1 year. Under the parametric Royston-Parmar model, stenting has a significant decrease in the RMST(-0.83 months; 95% CI: -1.30-0.37). Stenting continued to show worse outcomes up to the 3 year mark with a HR of 1.60 (95% CI: 1.11-2.32).

CONCLUSIONS AND RELEVANCE

There is an increased risk of peri- and post-procedural stroke and death over best medical therapy in patients with symptomatic ICAS who undergo PTAS. Further work is required to refine patient selection and mitigate peri-procedural risks.

Intracranial stenting compared to medical treatment alone for intracranial atherosclerosis patients: An updated meta-analysis

OBJECTIVE

Stroke is the second-leading cause of death globally. Intracranial atherosclerotic stenosis (ICAS) represents 10-15% of ischemic strokes in Western countries and up to 47% in Asian countries. Patients with ICAS have an especially high risk of stroke recurrence. The aim of this meta-analysis is to reassess recurrent stroke, transient ischemic attack (TIA), and other outcomes with stenting versus best medical management for symptomatic ICAS.

METHODS

The search protocol was developed a priori according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The OVID Medline, Embase, Web of Science, and Cochrane Library databases were searched from inception to August 14th, 2022.

RESULTS

This Meta-analysis Included Four Randomized Controlled Trials (Rcts), With A Total Number Of 991 Patients. The Mean Age Of Participants Was 57 Years. The Total Number Of Intracranial Stenting Patients Was 495, And The Number Of Medical Treatment Patients Was 496. The Included Studies Were Published Between 2011 And 2022. Two Studies Were Conducted In The Usa, And The Other Two In China. All Included Studies Compared Intracranial Stenting To Medical Treatment For Icas.

CONCLUSIONS

In patients with ischemic stroke due to symptomatic severe intracranial atherosclerosis, the rate of 30-day ischemic stroke, 30-day intracerebral hemorrhage, one-year stroke in territory or mortality favored the medical treatment alone without intracranial stenting. The risk of same-territory stroke at last follow-up, disabling stroke at last follow-up, and mortality did not significantly favor either group. Intracranial stenting for atherosclerosis did not result in significant benefit over medical treatment.

Impact of acute silent ischemic lesions on clinical outcomes of carotid revascularization

BACKGROUND

Previous literature has established an association between acute silent ischemic lesions (ASILs) and elevated susceptibility to future adverse clinical outcomes. The present study endeavors to scrutinize the prognostic significance of preprocedural ASILs, as detected through diffusion-weighted imaging and apparent diffusion coefficient metrics, in relation to subsequent adverse events-namely, stroke, myocardial infarction, and all-cause death-following carotid revascularization in a cohort of patients with symptomatic carotid stenosis.

MATERIALS AND METHODS

Subjects were extracted from a comprehensive retrospective dataset involving symptomatic carotid stenosis cases that underwent carotid revascularization at a tertiary healthcare institution in China, spanning January 2019 to March 2022. Of the 2663 initially screened patients (symptomatic carotid stenosis=1600; asymptomatic carotid stenosis=1063), a total of 1172 individuals with symptomatic carotid stenosis were retained for subsequent analysis. Stratification was implemented based on the presence or absence of ASILs. The primary endpoint constituted a composite measure of in-hospital stroke, myocardial infarction, or all-cause death. Both carotid endarterectomy (CEA) and carotid artery stenting (CAS) treatment modalities were individually subjected to propensity score-matched analyses.

RESULTS

Among the 584 subjects who underwent CEA, 91 ASIL-positive and 91 ASIL-negative (NASIL) cases were propensity score-matched. Notably, the ASIL cohort demonstrated a statistically significant augmentation in the risk of primary outcomes relative to the NASIL group [10.99 vs. 1.10%; absolute risk difference, 9.89% (95% CI: 3.12-16.66%); RR, 10.00 (95% CI: 1.31-76.52); P =0.01]. Similarly, within the 588 CAS-treated patients, 107 ASIL-positive and 107 NASIL cases were matched, revealing a correspondingly elevated risk of primary outcomes in the ASIL group [9.35 vs. 1.87%; absolute risk difference, 7.48% (95% CI: 1.39-13.56%); RR, 5.00 (95% CI: 1.12-22.28); P =0.02].

CONCLUSIONS

ASILs portend an elevated risk for grave adverse events postcarotid revascularization, irrespective of the specific revascularization technique employed-be it CEA or CAS. Thus, ASILs may serve as a potent biomarker for procedural risk stratification in the context of carotid revascularization.

Randomized Secondary Prevention Trials in Participants With Symptomatic Intracranial Atherosclerotic Stenosis

Intracranial atherosclerotic stenosis is a prevalent cause of ischemic stroke worldwide. Its association with silent cerebral infarcts and its contribution to cognitive impairment and dementia emphasize the critical need for disease prevention and effective management strategies. Despite extensive research on secondary stroke prevention treatment over the past several decades, intracranial atherosclerotic stenosis continues to exhibit a notably higher recurrent stroke rate compared with other causes. This review focuses on randomized secondary prevention trials involving antithrombotic therapy, endovascular treatment, open surgical therapy, and remote ischemic conditioning. It aims to provide an insightful overview of the major findings from each trial and their implications for future research efforts.

Comparative effect of stenting plus medical therapy vs medical therapy alone on the risk of stroke and death in patients with symptomatic intracranial stenosis: a systematic review and meta-analysis

BACKGROUND

Recently, several randomized controlled trials (RCTs) of stenting plus medical therapy versus medical therapy alone have been successfully conducted for the treatment of patients with symptomatic intracranial stenosis. This study aimed to evaluate differences between these two therapies in the risk of stroke and death.

METHODS

MEDLINE, EMBASE, the Cochrane Library, and ClinicalTrials.gov were systematically searched to identify relevant studies published before August 24, 2022. Review Manager 5.3 software was used to assess the data. The risk ratio (RR) was analysed and calculated with a random effect model or a fixed effects model.

RESULTS

We pooled 921 participants from three RCTs. Compared to the medical therapy alone group, the stenting plus medical therapy group had a higher risk of 30-day death or stroke (RR = 2.69 [1.64-4.41], P < 0.0001, I² = 0%). When the follow-up period exceeded 1 year (≥ 1 year), there was no significant difference in the risk of stroke or death between these two groups. The subgroup analysis showed that if the time from stroke onset to implantation was extended, additional stenting would have no effect on the risk of stroke or death, whether within 30 days or within 1 year (P = 0.16 and 0.78).

CONCLUSION

Medical therapy alone has a lower risk of stroke and death in the short term than stenting plus medical therapy, while no difference exists in the long term. More studies are still needed to further explore the precision strategy of stent implantation for symptomatic intracranial stenosis patients.

Effect of Stenting Plus Medical Therapy vs Medical Therapy Alone on Risk of Stroke and Death in Patients With Symptomatic Intracranial Stenosis: The CASSISS Randomized Clinical Trial

Importance

Prior randomized trials have generally shown harm or no benefit of stenting added to medical therapy for patients with symptomatic severe intracranial atherosclerotic stenosis, but it remains uncertain as to whether refined patient selection and more experienced surgeons might result in improved outcomes.

Objective

To compare stenting plus medical therapy vs medical therapy alone in patients with symptomatic severe intracranial atherosclerotic stenosis.

Design, Setting, and Participants

Multicenter, open-label, randomized, outcome assessor-blinded trial conducted at 8 centers in China. A total of 380 patients with transient ischemic attack or nondisabling, nonperforator (defined as nonbrainstem or non-basal ganglia end artery) territory ischemic stroke attributed to severe intracranial stenosis (70%-99%) and beyond a duration of 3 weeks from the latest ischemic symptom onset were recruited between March 5, 2014, and November 10, 2016, and followed up for 3 years (final follow-up: November 10, 2019).

Interventions

Medical therapy plus stenting (n = 176) or medical therapy alone (n = 182). Medical therapy included dual-antiplatelet therapy for 90 days (single antiplatelet therapy thereafter) and stroke risk factor control.

Main Outcomes and Measures

The primary outcome was a composite of stroke or death within 30 days or stroke in the qualifying artery territory beyond 30 days through 1 year. There were 5 secondary outcomes, including stroke in the qualifying artery territory at 2 years and 3 years as well as mortality at 3 years.

Results

Among 380 patients who were randomized, 358 were confirmed eligible (mean age, 56.3 years; 263 male [73.5%]) and 343 (95.8%) completed the trial. For the stenting plus medical therapy group vs medical therapy alone, no significant difference was found for the primary outcome of risk of stroke or death (8.0% [14/176] vs 7.2% [13/181]; difference, 0.4% [95% CI, -5.0% to 5.9%]; hazard ratio, 1.10 [95% CI, 0.52-2.35]; P = .82). Of the 5 prespecified secondary end points, none showed a significant difference including stroke in the qualifying artery territory at 2 years (9.9% [17/171] vs 9.0% [16/178]; difference, 0.7% [95% CI, -5.4% to 6.7%]; hazard ratio, 1.10 [95% CI, 0.56-2.16]; P = .80) and 3 years (11.3% [19/168] vs 11.2% [19/170]; difference, -0.2% [95% CI, -7.0% to 6.5%]; hazard ratio, 1.00 [95% CI, 0.53-1.90]; P > .99). Mortality at 3 years was 4.4% (7/160) in the stenting plus medical therapy group vs 1.3% (2/159) in the medical therapy alone group (difference, 3.2% [95% CI, -0.5% to 6.9%]; hazard ratio, 3.75 [95% CI, 0.77-18.13]; P = .08).

Conclusions and Relevance

Among patients with transient ischemic attack or ischemic stroke due to symptomatic severe intracranial atherosclerotic stenosis, the addition of percutaneous transluminal angioplasty and stenting to medical therapy, compared with medical therapy alone, resulted in no significant difference in the risk of stroke or death within 30 days or stroke in the qualifying artery territory beyond 30 days through 1 year. The findings do not support the addition of percutaneous transluminal angioplasty and stenting to medical therapy for the treatment of patients with symptomatic severe intracranial atherosclerotic stenosis.

Trial Registration

ClinicalTrials.gov Identifier: NCT01763320.