Infarct Pattern, Perfusion Mismatch Thresholds, and Recurrent Cerebrovascular Events in Symptomatic Intracranial Stenosis

Cerebral hemodynamics and stroke risks in symptomatic intracranial atherosclerotic stenosis with internal versus cortical borderzone infarcts: A computational fluid dynamics study

There may be different mechanisms underlying internal (IBZ) and cortical (CBZ) borderzone infarcts in intracranial atherosclerotic stenosis. In 84 patients with symptomatic, 50-99% atherosclerotic stenosis of M1 middle cerebral artery (MCA-M1) with acute borderzone infarcts in diffusion-weighted imaging, we classified the infarct patterns as isolated IBZ (n = 37), isolated CBZ (n = 31), and IBZ+CBZ (n = 16) infarcts. CT angiography-based computational fluid dynamics models were constructed to quantify translesional, post-stenotic to pre-stenotic pressure ratio (PR) in the MCA-M1 lesion. Those with IBZ infarcts were more likely to have a low PR (indicating impaired antegrade flow across the lesion) than those without (p = 0.012), and those with CBZ infarcts were more likely to have coexisting small cortical infarcts (indicating possible embolism) than those without (p = 0.004). In those with isolated IBZ or CBZ infarcts, low PR was independently associated with isolated IBZ infarcts (adjusted odds ratio = 4.223; p = 0.026). These two groups may also have different trajectories in the stroke risks under current medical treatment regimen, with a higher risk of same-territory ischemic stroke recurrence within 3 months in patients with isolated IBZ infarcts than isolated CBZ infarcts (17.9% versus 0.0%; log-rank p = 0.023), but similar risks later in 1 year.

Stroke mechanisms in adult moyamoya disease: The association between infarction patterns and quantitative magnetic resonance angiography flow state

INTRODUCTION

Flow augmentation is the mainstay treatment for moyamoya disease as hemodynamic failure is believed to be the dominant mechanism. We aimed to investigate the mechanisms of stroke in moyamoya disease by assessing the relationship between infarction patterns and quantitative magnetic resonance angiography flow state.

METHODS

A retrospective study of adult patients with suspected MMD who presented with MRI confirmed acute ischemic stroke predating or following QMRA by a maximum of six months between 2009 and 2021 was conducted. Of the 177 consecutive patients with MMD who received QMRA, 35 patients, consisting of 41 hemispheres, met inclusion criteria. Flow-status was dichotomized into low-flow and normal-flow state based on previously established criteria.

RESULTS

Mixed infarction pattern was the most frequent finding (70.7 %), followed by embolic (17.1 %), perforator (7.3 %), and internal borderzone (IBZ) (4.9 %). Infarction patterns were further dichotomized into IBZ+ (internal borderzone alone or mixed) and IBZ- (no internal borderzone constituent). Low-flow states were not significantly more frequent in the IBZ+ compared to IBZ- population (48.4 % vs. 20.0 %, p = 0.14). Ipsilateral posterior cerebral artery fractional flow was significantly higher with IBZ+ compared to IBZ- (345.0 % vs. 214.7 %, p = 0.04).

CONCLUSION

Mixed infarction pattern was the most common pattern of infarction in patients with moyamoya disease, implying hypoperfusion and thromboembolism are codominant stroke mechanisms. An association between ICA flow status and infarction pattern was not found, although QMRA evidence of more robust posterior cerebral artery leptomeningeal collaterals was found in patients with a hypoperfusion contribution to their stroke mechanism.

Borderzone Infarcts and Recurrent Cerebrovascular Events in Symptomatic Intracranial Arterial Stenosis: A Systematic Review and Meta-Analysis

BACKGROUND AND PURPOSE

Intracranial arterial stenosis (ICAS)-related stroke occurs due to three primary mechanisms with distinct infarct patterns: (1) borderzone infarcts (BZI) due to impaired distal perfusion, (2) territorial infarcts due to distal plaque/thrombus embolization, and (3) plaque progression occluding perforators. The objective of the systematic review is to determine whether BZI secondary to ICAS is associated with a higher risk of recurrent stroke or neurological deterioration.

METHODS

As part of this registered systematic review (CRD42021265230), a comprehensive search was performed to identify relevant papers and conference abstracts (with ≥20 patients) reporting initial infarct patterns and recurrence rates in patients with symptomatic ICAS. Subgroup analyses were performed for studies including any BZI versus isolated BZI and those excluding posterior circulation stroke. The study outcome included neurological deterioration or recurrent stroke during follow-up. For all outcome events, corresponding risk ratios (RRs) and 95% confidence intervals (95% CI) were calculated.

RESULTS

A literature search yielded 4,478 records with 32 selected during the title/abstract triage for full text; 11 met inclusion criteria and 8 studies were included in the analysis (n=1,219 patients; 341 with BZI). The meta-analysis demonstrated that the RR of outcome in the BZI group compared to the no BZI group was 2.10 (95% CI 1.52-2.90). Limiting the analysis to studies including any BZI, the RR was 2.10 (95% CI 1.38-3.18). For isolated BZI, RR was 2.59 (95% CI 1.24-5.41). RR was 2.96 (95% CI 1.71-5.12) for studies only including anterior circulation stroke patients.

CONCLUSION

This systematic review and meta-analysis suggests that the presence of BZI secondary to ICAS may be an imaging biomarker that predicts neurological deterioration and/or stroke recurrence.

Recurrence risk in symptomatic intracranial stenosis treated medically in the real world

BACKGROUND

The risk of early recurrence in medically treated patients with intracranial atherosclerotic stenosis (ICAS) may differ in clinical trials versus real-world settings. Delayed enrollment may contribute to lower event rates in ICAS trials. We aim to determine the 30-day recurrence risk in a real-world setting of symptomatic ICAS.

METHODS

We used a comprehensive stroke center stroke registry to identify hospitalized patients with acute ischemic stroke or TIA due to symptomatic 50-99% ICAS. The outcome was recurrent stroke within 30 days. We used adjusted Cox regression models to identify factors associated with increased recurrence risk. We also performed a comparison of 30-day recurrent stroke rates in real world cohorts and clinical trials.

RESULTS

Among 131 hospitalizations with symptomatic 50-99% ICAS over 3 years, 80 hospitalizations of 74 patients (mean age 71.6 years, 55.41% men) met the inclusion criteria. Over 30 days, 20.6 % had recurrent stroke; 61.5% (8/13) occurred within first 7 days. The risk was higher in patients not receiving dual antiplatelet therapy (HR 3.92 95% CI 1.30-11.84, p = 0.015) and hypoperfusion mismatch volume >3.5 mL at a T max>6 s threshold (HR 6.55 95% CI 1.60-26.88, p < 0.001). The recurrence risk was similar to another real world ICAD cohort (20.2%), and higher than that seen in clinical trials (2.2%-5.7%), even in those treated with maximal medical treatment or meeting inclusion criteria for trials.

CONCLUSIONS

In patients with symptomatic ICAS, the real-world recurrence of ischemic events is higher than that seen in clinical trials, even in subgroups receiving the same pharmacological treatment strategies.

Borderzone infarction and recurrent stroke in intracranial atherosclerosis

BACKGROUND

Intracranial stenosis (ICAS) is a common cause of stroke worldwide and patients with symptomatic ICAS exhibit a high rate of recurrence, particularly in the early period after the initial event. In this study, we aimed to study the association between borderzone infarct and recurrent ischemic stroke in patients hospitalized with symptomatic ICAS.

METHODS

This is a retrospective single center study that included patients hospitalized with acute ischemic stroke in the setting of intracranial stenosis (50% or more and an acute ischemic stroke in the territory supplied by the stenosed artery) over a 32-month period. We excluded patients who did not receive a brain MRI or did not have an infarct on brain imaging. The primary predictor is infarct pattern (any borderzone vs. no borderzone infarct) and the primary outcome was recurrent cerebrovascular events (RCVE) within 90 days. We used unadjusted, and age and sex adjusted logistic regression models to determine associations between infarct pattern and RCVE at 90-days.

RESULTS

Among 99 patients who met the inclusion criteria (4 tandem), the mean age was 70.1 ± 11.2 years and 41.4% were women; 43 had borderzone infarcts and 19 had RCVE. In adjusted binary logistic regression analysis, borderzone infarct was associated with increased risk of RCVE (adjusted OR 4.00 95% CI 1.33-11.99, p=0.013). The association between borderzone infarction and RCVE was not different among anterior circulation ICAD (adjusted HR 2.85 95% CI 0.64-12.76, p=0.172) vs. posterior circulation ICAD (adjusted HR 6.69 95% CI 1.06-42.11, p=0.043), p-value for interaction = 0.592.

CONCLUSION

In real world post-SAMMPRIS medically treated patients with ICAD, the borderzone infarct pattern was associated with 90-day RCVE. Borderzone infarcts are likely a surrogate marker of impaired distal blood flow, highlighting the importance of targeting stroke mechanisms and developing alternative treatment strategies for high-risk cohorts.

Recurrent stroke risk in intracranial atherosclerotic disease

Recurrent stroke risk secondary to intracranial atherosclerotic disease remains high despite aggressive medical treatment. This risk is further amplified in subgroups possessing biomarkers of hemodynamic insufficiency and potential for embolization, which have been shown to be independently and synergistically predictive of recurrent stroke. Luminal stenosis was predominantly used as entry criteria in major treatment trials, discounting the potential role of hemodynamics from primary analyses, limiting the strength of evidence and conclusions of these biomarkers to post-hoc analyses and other natural history studies. Future treatment trials should consider stratifying patients using a combination of these high-risk biomarkers. In the absence of trials, risk stratifying patients based on the presence of these markers may lend to more individualized clinical decisions. We aimed to summarize the studies that have investigated the relationship between biomarkers and their role in predicting recurrent stroke risk in intracranial atherosclerotic disease.

Vertebrobasilar Stroke: Association Between Infarction Patterns and Quantitative Magnetic Resonance Angiography Flow State

Background

Treatment and prognosis of vertebrobasilar atherosclerotic disease differs depending on stroke mechanism, such as artery‐to‐artery embolism, branch atheromatous disease, and hemodynamic ischemia. Our aim was to investigate the relationship between infarction pattern and flow status using quantitative magnetic resonance angiography (QMRA), to determine the validity of using infarction patterns to infer stroke mechanism.

Methods and Results

This is a retrospective study of patients with ischemic stroke with intra‐ or extracranial vertebrobasilar atherosclerotic stenosis, who underwent magnetic resonance imaging of the brain, neurovascular imaging, and QMRA, between 2009 and 2021. Patients with cerebral infarction predating or following QMRA by ≥1 year, or QMRA studies performed for basilar thrombosis, vertebral dissection, or only postangioplasty/stenting, were excluded. Poststenotic flow (basilar and posterior cerebral arteries) was dichotomized as low‐flow or normal‐flow based on published criteria. Of 1211 consecutive patients who underwent QMRA noninvasive optimal analysis, 69 met inclusion. Mixed patterns were most common (46.4%), followed by perforator (23.2%), borderzone (14.5%), and territorial (15.9%). Patients with low‐flow had a significantly higher rate of borderzone+ patterns (borderzone alone or in mixed pattern) compared with patients with normal‐flow (77.4% low‐flow versus 39.5% normal‐flow, P=0.002). Borderzone+ patterns were associated with 61.5% probability of low‐flow state, while no borderzone (perforator/territorial) patterns were associated with 76.7% probability of normal‐flow state.

Conclusions

Borderzone infarction pattern (alone or mixed) was associated with low poststenotic posterior circulation flow by QMRA. However, borderzone pattern only moderately predicted low‐flow state, and may be an unreliable flow marker. Therefore, infarct topography may complement, but should not replace hemodynamic studies to establish flow status.

Intracranial atherosclerotic disease mechanistic subtypes drive hypoperfusion patterns

BACKGROUND AND PURPOSE

In symptomatic intracranial atherosclerotic stenosis (ICAS), borderzone infarct pattern and perfusion mismatch are associated with increased risk of recurrent strokes, which may reflect the shared underlying mechanism of hypoperfusion distal to the intracranial atherosclerosis. Accordingly, we hypothesized a correlation between hypoperfusion volumes and ICAS infarct patterns based on the respective underlying mechanistic subtypes.

METHODS

We conducted a retrospective analysis of consecutive symptomatic ICAS cases, acute strokes due to subocclusive (50%-99%) intracranial stenosis. The following mechanistic subtypes were assigned based on the infarct pattern on the diffusion-weighted imaging: Branch occlusive disease (BOD), internal borderzone (IBZ), and thromboembolic (TE). Perfusion parameters, obtained concurrently with the MRI, were studied in each group.

RESULTS

A total of 42 patients (57% women, mean age 71 ± 13 years old) with symptomatic ICAS received MRI within 24 h of acute presentation. Fourteen IBZ, 11 BOD, and 17 TE patterns were identified. IBZ pattern yielded higher total T_max > 4 s and T_max > 6 s perfusion delay volumes, as well as corresponding T_max  > 4 s and T_max  > 6 s mismatch volume, compared to BOD. TE pattern exhibited greater median T_max  > 6 s hypoperfusion delay in volume compared to BOD. In IBZ versus TE, the volume difference between T_max > 4 s and T_max > 6 s (Δ T_max  > 4 s - T_max  > 6 s) was substantially greater.

CONCLUSION

ICAS infarct patterns, in keeping with their respective underlying mechanisms, may correlate with distinct perfusion profiles.

Predictors of Early Infarct Recurrence in Patients With Symptomatic Intracranial Atherosclerotic Disease

BACKGROUND AND PURPOSE

While prior studies identified risk factors for recurrent stroke in patients with symptomatic intracranial atherosclerotic disease, few have assessed risk factors for early infarct recurrence.

METHODS

We performed a post hoc analysis of the MYRIAD study (Mechanisms of Early Recurrence in Intracranial Atherosclerotic Disease) of intracranial atherosclerotic disease patients with recent (<21 days) stroke/transient ischemic attack, 50% to 99% stenosis and who underwent 6- to 8-week magnetic resonance imaging (MRI) per protocol. Infarct recurrence was defined as new infarcts in the territory of the symptomatic artery on brain MRI at 6 to 8 weeks compared to index brain MRI. Qualifying events and clinical and imaging outcomes were centrally ascertained by 2 independent reviewers. We assessed the association between baseline clinical and imaging variables and recurrent infarct in bivariate models and multivariable logistic regression to identify independent predictors of infarct recurrence.

RESULTS

Of 105 enrolled patients in MYRIAD, 89 (84.8%) were included in this analysis (mean age, 64±12 years, 54 [60.7%] were male, and 53 [59.6%] were White). The median time from qualifying event to MRI was 51+16 days, on which 22 (24.7%) patients had new or recurrent infarcts. Younger age (57.7 versus 66.0 years; P<0.01), diabetes (32.6% versus 14.6%, P=0.05), index stroke (31.3% versus 4.6%, P=0.01), anterior circulation location of stenosis (29.7% versus 12.0%, P=0.08), number of diffusion-weighted imaging lesions (>1: 40.0%, 1: 26.9% versus 0: 4.4%, P<0.01), and borderzone infarct pattern (63.6% versus 25.0%, P=0.01) on baseline MRI were associated with new or recurrent infarcts. Age (adjusted odds ratio, 0.93 [95% CI, 0.89-0.98], P<0.01) and number of diffusion-weighted imaging lesions (adjusted odds ratio, 3.24 [95% CI, 1.36-7.71], P<0.01) were independently associated with recurrent infarct adjusting for hypertension, diabetes, and stenosis location (anterior versus posterior circulation).

CONCLUSIONS

An index multi-infarct pattern is associated with early recurrent infarcts, a finding that might be explained by plaque instability and artery-to-artery embolism. Further investigation of plaque vulnerability in intracranial atherosclerotic disease is needed. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02121028.

Impaired Distal Perfusion Predicts Length of Hospital Stay in Patients with Symptomatic Middle Cerebral Artery Stenosis

BACKGROUND AND PURPOSE

Perfusion imaging can risk stratify patients with symptomatic intracranial stenosis. We aim to determine the association between perfusion delay and length of hospital stay (LOS) in symptomatic middle cerebral artery (MCA) stenosis patients.

METHODS

This is a retrospective study of consecutive patients admitted to a comprehensive stroke center over 5 years with ischemic stroke or transient ischemic attack (TIA) within 7 days of symptom onset due to MCA stenosis (50-99%) and underwent perfusion imaging. Patients were divided into three groups: mismatch volume ≥ 15 cc based on T max > 6 second delay, T max 4-6 second delay, and <4 second delay. The outcome was LOS, both as a continuous variable and categorical (≥7 days [prolonged LOS] vs. <7 days). We used adjusted regression analyses to determine the association between perfusion categories and LOS.

RESULTS

One hundred and seventy eight of 194 patients met the inclusion criteria. After adjusting for age and NIHSS, T max >6 second mismatch was associated with prolonged LOS (OR 2.94 95% CI 1.06-8.18; P = .039), but T max 4-6 second was not (OR 1.45 95% CI .46-4.58, P = .528). We found similar associations when LOS was a continuous variable for T max > 6 second (β coefficient = 2.01, 95% CI .05-3.97, P = .044) and T max 4-6 second (β coefficient = 1.24, 95% CI -.85 to 3.34, P = .244).

CONCLUSION

In patients with symptomatic MCA stenosis, T max > 6 second perfusion delay is associated with prolonged LOS. Prospective studies are needed to validate our findings.

Imaging Patterns of Recurrent Infarction in the Mechanisms of Early Recurrence in Intracranial Atherosclerotic Disease (MyRIAD) Study

Introduction: While much is known about recurrent clinical events in patients with intracranial atherosclerotic disease (ICAD), there is limited data on characteristics of recurrent infarcts.

Methods: The NIH-funded MyRIAD prospective, observational study was designed to identify mechanisms of ischemia and predictors of recurrence in ICAD. Recurrent infarction was assessed on MRI at 6–8 weeks. We reviewed the DWI/ADC and FLAIR sequences in patients with recurrent stroke and characterized the number of infarcts, infarct location, size, and patterns based on whether they were borderzone (BZ), perforator (SC/P), cortical or territorial (C/T), and mixed. Temporal characteristics were delineated by ADC/FLAIR correlation.

Results: Of the 89 patients with 6–8 weeks MRI, 22 (24.7%) had recurrent infarcts in the territory of the symptomatic artery. Recurrent infarcts were evident on DWI in 63.6% and single infarcts in 54.5%. The median recurrent infarct volume was 2.0 cm³ compared to median index infarct volumes of 2.5 cm³. A mixed infarct pattern was most common (40.9%), followed by borderzone (22.7%), cortical or territorial (27.3%), while only 9.1% were in a perforator artery distribution. Amongst those with a mixed pattern, 8/9 had a borderzone distribution infarct as part of their mixed infarct pattern.

Conclusion: These findings provide novel data on the characteristics of early recurrent infarcts in patients with symptomatic ICAD.

Hypoperfusion Distal to Anterior Circulation Intracranial Atherosclerosis is Associated with Recurrent Stroke

BACKGROUND AND PURPOSE

In patients with symptomatic vertebrobasilar intracranial atherosclerotic disease (ICAD), impaired distal flow predicts recurrent stroke, but limited data exist on the association between perfusion status and recurrent stroke in anterior circulation ICAD.

METHODS

This is a retrospective study of patients hospitalized for symptomatic ICAD with 50-99% stenosis of the intracranial carotid or middle cerebral artery. The primary outcome is recurrent symptomatic ischemic stroke in the territory of the artery with ≥50% stenosis within 90 days. The primary predictor is distal hypoperfusion on magnetic resonance (MR) or computed tomography (CT) perfusion, defined as a ≥15 mL volume of territory of the symptomatic artery with Tmax >6 seconds.

RESULTS

Fifty patients met inclusion criteria, including 15 (30%) with recurrent stroke and 15 (30%) with distal hypoperfusion. Distal hypoperfusion was present in 10 of 15 (66.7%) with recurrent stroke versus 5 of 35 (14.3%) without recurrent stroke (P < .001). The hazard ratio for recurrent stroke in patients with distal hypoperfusion was 6.80 (95% confidence interval [CI] 2.31-20.0).

CONCLUSION

Distal hypoperfusion in acutely symptomatic ICAD with 50-99% stenosis is associated with stroke recurrence. Distal hypoperfusion could be used to enrich future trials of secondary stroke prevention in ICAD patients.

Intracranial Atherosclerosis: A Disease of Functional, not Anatomic Stenosis? How Trans-Stenotic Pressure Gradients Can Help Guide Treatment

BACKGROUND

Most trials have assessed intracranial atherosclerotic disease (ICAD) severity based on angiographic stenosis. However, anatomic stenosis might not accurately identify the actual state of functional post-stenotic flow limitation.

OBJECTIVE

To investigate whether angiographic stenosis correlates with physiologic distal flow limitation, measured as trans-stenotic pressure gradients, in ICAD patients.

METHODS

In patients referred for endovascular treatment of anterior circulation symptomatic ICAD who failed maximal medical therapy (MMT) per SAMMPRIS (Stenting versus Aggressive Medical Therapy for Intracranial Arterial Stenosis) criteria, angiographic luminal diameters and percentages of stenosis were correlated with trans-stenotic pressure gradients, calculated as distal/proximal pressure ratios (DPPR) and proximal minus distal pressure gradients (PDPG), by way of Spearman correlation coefficients.

RESULTS

Nine patients (3 men, 6 women) were evaluated. Atherosclerotic lesions' locations included internal carotid artery in 5 subjects (2 cavernous, 3 supraclinoid) and proximal middle cerebral artery (M1) in 4 patients. Mean percentage of stenosis was 80 ± 8% (range 75%-94%). Minimal lumen diameter at the most stenotic ICAD site ranged from 0.2 to 0.9 mm (0.59 ± 0.41 mm). DPPR ranged from 0.38 to 0.63 (0.56 ± 0.14). PDPG ranged from 35 to 57 mm Hg (50 ± 8 mm Hg). Spearman coefficients showed no correlation between DPPR or PDPG and angiographic minimal luminal diameters or percentages of stenosis. There were no procedural complications related to trans-stenotic pressure measurements.

CONCLUSION

Angiographic stenosis does not reflect the physiologic severity of distal flow limitation in patients with ICAD. Hemodynamic assessment using trans-stenotic pressure ratios and gradients may serve as a more reliable predictive biomarker for MMT failure and response to revascularization.

Poststroke Montreal Cognitive Assessment and Recurrent Stroke in Patients With Symptomatic Intracranial Atherosclerosis

BACKGROUND AND PURPOSE

Cognitive impairment occurs in 20%-40% of stroke patients and is a predictor of long-term morbidity and mortality. In this study, we aim to determine the association between poststroke cognitive impairment and stroke recurrence risk, in patients with anterior versus posterior circulation intracranial stenosis.

METHODS

This is a post-hoc analysis of the Stenting and Aggressive Medical Therapy for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) trial. The primary predictor was poststroke cognitive function measured by Montreal Cognitive Assessment (MOCA) at 3-6 months and the primary outcome was recurrent ischemic stroke. We used univariate and multivariable cox-regression models to determine the associations between MOCA at 3-6 months and recurrent stroke.

RESULTS

Of the 451 patients enrolled in SAMMPRIS, 393 patients met the inclusion criteria. The mean age of the sample (in years) was 59.5 ± 11.3, 62.6% (246 of 393) were men. Fifty patients (12.7%) had recurrent ischemic stroke during a mean follow up of 2.7 years. The 3-6 month MOCA score was performed on 351 patients. In prespecified multivariable models, there was an association between 3 and 6 month MOCA and recurrent stroke (hazard ratio [HR] per point increase .93 95% confidence interval [CI] .88-.99, P = .040). This effect was present in anterior circulation stenosis (adjusted HR per point increase .92 95% CI .85-0.99, P = .022) but not in posterior circulation artery stenosis (adjusted HR per point increase 1.00 95% .86-1.16, P = .983).

CONCLUSIONS

Overall, we found weak associations and trends between MoCA at 3-6 months and stroke recurrence but more notable and stronger associations in certain subgroups. Since our study is underpowered, larger studies are needed to validate our findings and determine the mechanism(s) behind this association.

Peri-procedural stroke or death in stenting of symptomatic severe intracranial stenosis

BACKGROUND AND PURPOSE

There are limited data on predictors of 30-day stroke or death in patients with symptomatic intracranial atherosclerosis (sICAS) undergoing stenting. We aim to determine the factors associated with stroke or death at 30 days in the stenting arm of the SAMMPRIS trial.

METHODS

This is a post-hoc analysis of the SAMMPRIS trial including patients who underwent angioplasty/stenting. We compared patient-specific variables, lesion-specific variables, procedure-specific variables, and FDA-approved indications between patients with and without the primary outcome (stroke or death at 30 days). Logistic regression analyses were performed to evaluate associations with the primary outcome.

RESULTS

We identified 213 patients, 30 of whom (14.1%) met the primary outcome. Smoking status and lesion length were associated with the primary outcome: the odds of stroke or death for non-smokers versus smokers (adjusted OR 4.46, 95% CI 1.79 to 11.1, p=0.001) and for increasing lesion length in millimeters (adjusted OR 1.20, 95% CI 1.02 to 1.39, p=0.029). These had a modest predictive value: absence of smoking history (sensitivity 66.7%, specificity 65.4%) and lesion length (area under curve 0.606). Furthermore, event rates were not significantly different between patients with and without the FDA-approved indication for stenting (15.9% vs 12%, p=0.437).

CONCLUSION

In SAMMPRIS patients who underwent angioplasty/stenting, neither clinical and neuroimaging variables nor the FDA indication for stenting reliably predicted the primary outcome. Further work in identifying reliable biomarkers of stroke/death in patients with sICAS is needed before considering new clinical trials of stenting.

TRIAL REGISTRATION NUMBER

SAMMPRIS NCT00576693; Results.