Interpretation and implications of the prematurely terminated Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in the Intracranial Stenosis (SAMMPRIS) trial

Self-expanding versus balloon expandable stent for intracranial arterial stenosis: A systematic review and meta-analysis

BACKGROUND AND PURPOSE

There are limited data regarding the comparison of balloon expandable stents (BES) and self-expanding stents (SES) for the treatment of intracranial arterial stenosis.

METHODS

We conducted a systematic review to identify studies that compared SES and BES in patients with symptomatic intracranial arterial stenosis. Data were extracted from relevant studies found through a search of PubMed, Scopus, and Web of Science until from January 1, 2010 to September 28, 2023. Statistical pooling with random-effects meta-analysis was undertaken to compare the rates/severity of postprocedure stenosis, technical success, 30-day stroke and/or death, cumulative clinical endpoints, and restenosis rates.

RESULTS

A total of 20 studies were included. The standardized mean difference (SMD) for postprocedure stenosis (%) was significantly lower (SMD: -0.52, 95% confidence interval [CI]: -0.79 to -0.24, p < .001, 10 studies involving 1515 patients) with BES. The odds for 30-day stroke and/or death were significantly lower (odds ratio [OR] 0.68, 95% CI: 0.50-0.94, p = .019, 15 studies involving 2431 patients), and cumulative clinical endpoints on follow-up were nonsignificantly lower (OR 0.64, 95% CI: 0.30-1.37, p = .250, 10 studies involving 947 patients) with BES. The odds for restenosis during follow-up were significantly lower (OR 0.50, 95% CI: 0.31-0.80, p = .004, 13 studies involving 1115 patients) with BES.

CONCLUSIONS

Compared with SES, BES were associated with lower rates of postprocedure 30-day stroke and/or death with lower rates of restenosis during follow up and the treatment of symptomatic intracranial arterial stenosis.

Prevalence, predictors, and prognosis of symptomatic intracranial stenosis in patients with transient ischaemic attack or minor stroke: a population-based cohort study

BACKGROUND

Symptomatic intracranial stenosis was perceived to convey a high risk of recurrent stroke, but two previous trials (SAMMPRIS and VISSIT) did not show superiority of intracranial stenosis stenting over intensive medical management alone. These findings were partly due to a lower than expected risk of recurrent stroke without stenting, possibly reflecting the young age of recruits (median age <60 years), and raise questions about generalisability to routine clinical practice. We therefore studied the age-specific prevalence, predictors, and prognosis of symptomatic intracranial stenosis in a population-based cohort of patients with transient ischaemic attack and minor stroke on intensive medical management.

METHODS

The Oxford Vascular Study (OXVASC) is a prospective incidence cohort study of all vascular events in a population of 92 728 people residing in Oxfordshire, UK. All patients, irrespective of age, with transient ischaemic attack and minor ischaemic stroke occurring between March 1, 2011, and March 1, 2018 (follow-up to Sept 28, 2018), were ascertained with multiple methods, including assessment in a dedicated daily emergency clinic and daily review of all hospital admissions. Imaging was by MR angiography of the intracranial and cervicocranial arteries, by CT angiography if MR angiography was contraindicated, and by transcranial Doppler and carotid ultrasound if CT angiography was contraindicated. All patients received intensive medical treatment without stenting, and those with intracranial vascular imaging were analysed in our study, which assessed the age-specific prevalence of 50-99% intracranial stenosis and the associated stroke risk of 50-99% and 70-99% stenosis (adjusted for age and vascular risk factors) during follow-up to Sept 28, 2018.

FINDINGS

Of 1368 eligible patients with intracranial vascular imaging, 241 (17·6%) had 385 50-99% symptomatic or asymptomatic intracranial stenosis. The prevalence of symptomatic 50-99% intracranial stenosis increased from 29 (4·9%) of 596 at younger than 70 years to 10 (19·6%) of 51 at 90 years or older (p_trend<0·0001). Of 94 patients with 50-99% symptomatic intracranial stenosis, 14 (14·9%) had recurrent strokes (12 ischaemic and two haemorrhagic) during a median follow-up of 2·8 years (IQR 1·5-4·6). Although symptomatic intracranial stenosis conveyed an increased risk of ischaemic stroke compared with no intracranial stenosis (adjusted hazard ratio 1·43, 95% CI 1·04-1·96), the risk of same-territory ischaemic stroke in patients with 70-99% symptomatic intracranial stenosis tended to be less than those reported in the non-stenting groups of the previous trials (1-year risk 5·6% [95% CI 0·0-13·0] vs 9·4% [3·1-20·7] in VISSIT; 2-year risk 5·6% [0·0-13·0] vs 14·1% [10·1-19·4] in SAMMPRIS).

INTERPRETATION

The prevalence of 50-99% symptomatic intracranial stenosis increases steeply with age in predominantly Caucasian patients with transient ischaemic attack and minor ischaemic stroke. However, the risk of recurrent stroke on intensive medical treatment of symptomatic intracranial stenosis is consistent with the two previous randomised controlled trials in younger cohorts, supporting the generalisability of the trial results to routine practice.

FUNDING

Wellcome Trust, Wolfson Foundation, British Heart Foundation, National Institute for Health Research, National Institute for Health Research Oxford Biomedical Research Centre, Association of British Neurologists.

Recent advances in the management of transient ischemic attacks

Significant advances in our understanding of transient ischemic attack (TIA) have taken place since it was first recognized as a major risk factor for stroke during the late 1950's. Recently, numerous studies have consistently shown that patients who have experienced a TIA constitute a heterogeneous population, with multiple causative factors as well as an average 5–10% risk of suffering a stroke during the 30 days that follow the index event. These two attributes have driven the most important changes in the management of TIA patients over the last decade, with particular attention paid to effective stroke risk stratification, efficient and comprehensive diagnostic assessment, and a sound therapeutic approach, destined to reduce the risk of subsequent ischemic stroke. This review is an outline of these changes, including a discussion of their advantages and disadvantages, and references to how new trends are likely to influence the future care of these patients.

Elective treatment of intracranial stenosis with the balloon-expandable Pharos Vitesse stent: 30-day stroke rate and complications

BACKGROUND AND PURPOSE

Analysis of procedural results and 30-day outcome after intracranial angioplasty and stenting (ICAS) with the balloon-expandable Pharos Vitesse stent system in carefully selected high-risk patients in two high-volume neurovascular centers.

MATERIALS AND METHODS

92 patients scheduled for elective ICAS using Pharos Vitesse between August, 2008 and August, 2011 were included. All patients showed high-grade intracranial stenosis and recurrent ischemic events despite best medical treatment at that time. The stroke rates and complications were divided into procedural and 30-day short-term events.

RESULTS

Successful stent placement was achieved in all but one patient. Ischemic procedural complications occurred in three subjects. 30-Day complications and strokes were seen in four patients: two minor ischemic strokes, one fatal hemorrhage and one non-stroke-related death. Overall, strokes occurred in 6 out of 92 patients (6.5%, 95% CI 3.0% to 13.5%). The total stroke and death rate was 7.6% (95% CI 3.7% to 14.9%). No significant correlation with previously reported risk factors could be found, although a higher rate of ischemic strokes (four out of five) in the posterior circulation was recorded.

CONCLUSIONS

In patients with intracranial stenosis who experience recurrent ischemic events despite best medical treatment, ICAS, using the balloon-expandable Pharos Vitesse stent, may still be considered as an individual treatment option in high-volume neurovascular centers.

Rapid, responsive, relevant (R3) research: a call for a rapid learning health research enterprise

Our current health research enterprise is painstakingly slow and cumbersome, and its results seldom translate into practice. The slow pace of health research contributes to findings that are less relevant and potentially even obsolete. To produce more rapid, responsive, and relevant research, we propose approaches that increase relevance via greater stakeholder involvement, speed research via innovative designs, streamline review processes, and create and/or better leverage research infrastructure. Broad stakeholder input integrated throughout the research process can both increase relevance and facilitate study procedures. More flexible and rapid research designs should be considered before defaulting to the traditional two-arm randomized controlled trial (RCT), but even traditional RCTs can be designed for more rapid findings. Review processes for grant applications, IRB protocols, and manuscript submissions can be better streamlined to minimize delays. Research infrastructures such as rapid learning systems and other health information technologies can be leveraged to rapidly evaluate new and existing treatments, and alleviate the extensive recruitment delays common in traditional research. These and other approaches are feasible but require a culture shift among the research community to value not only methodological rigor, but also the pace and relevance of research.

Is there a future for endovascular treatment of intracranial atherosclerotic disease after Stenting and Aggressive Medical Management for Preventing Recurrent Stroke and Intracranial Stenosis (SAMMPRIS)?

The Stenting and Aggressive Medical Management for Preventing Recurrent Stroke and Intracranial Stenosis (SAMMPRIS) trial, a randomized clinical trial comparing aggressive medical management to stenting with aggressive medical management for symptomatic intracranial stenosis, was prematurely halted when a high rate of periprocedural events was found in the stent arm. The trial also demonstrated a high rate of stroke with medical management. This article explores possible reasons for these outcomes and discusses some weaknesses of the trial. Against this background endovascular therapy should continue to be explored in the treatment of this disease.