Apixaban to Prevent Recurrence After Cryptogenic Stroke in Patients With Atrial Cardiopathy: The ARCADIA Randomized Clinical Trial

Importance

Atrial cardiopathy is associated with stroke in the absence of clinically apparent atrial fibrillation. It is unknown whether anticoagulation, which has proven benefit in atrial fibrillation, prevents stroke in patients with atrial cardiopathy and no atrial fibrillation.

Objective

To compare anticoagulation vs antiplatelet therapy for secondary stroke prevention in patients with cryptogenic stroke and evidence of atrial cardiopathy.

Design, Setting, and Participants

Multicenter, double-blind, phase 3 randomized clinical trial of 1015 participants with cryptogenic stroke and evidence of atrial cardiopathy, defined as P-wave terminal force greater than 5000 μV × ms in electrocardiogram lead V1, serum N-terminal pro-B-type natriuretic peptide level greater than 250 pg/mL, or left atrial diameter index of 3 cm/m2 or greater on echocardiogram. Participants had no evidence of atrial fibrillation at the time of randomization. Enrollment and follow-up occurred from February 1, 2018, through February 28, 2023, at 185 sites in the National Institutes of Health StrokeNet and the Canadian Stroke Consortium.

Interventions

Apixaban, 5 mg or 2.5 mg, twice daily (n = 507) vs aspirin, 81 mg, once daily (n = 508).

Main Outcomes and Measures

The primary efficacy outcome in a time-to-event analysis was recurrent stroke. All participants, including those diagnosed with atrial fibrillation after randomization, were analyzed according to the groups to which they were randomized. The primary safety outcomes were symptomatic intracranial hemorrhage and other major hemorrhage.

Results

With 1015 of the target 1100 participants enrolled and mean follow-up of 1.8 years, the trial was stopped for futility after a planned interim analysis. The mean (SD) age of participants was 68.0 (11.0) years, 54.3% were female, and 87.5% completed the full duration of follow-up. Recurrent stroke occurred in 40 patients in the apixaban group (annualized rate, 4.4%) and 40 patients in the aspirin group (annualized rate, 4.4%) (hazard ratio, 1.00 [95% CI, 0.64-1.55]). Symptomatic intracranial hemorrhage occurred in 0 patients taking apixaban and 7 patients taking aspirin (annualized rate, 1.1%). Other major hemorrhages occurred in 5 patients taking apixaban (annualized rate, 0.7%) and 5 patients taking aspirin (annualized rate, 0.8%) (hazard ratio, 1.02 [95% CI, 0.29-3.52]).

Conclusions and Relevance

In patients with cryptogenic stroke and evidence of atrial cardiopathy without atrial fibrillation, apixaban did not significantly reduce recurrent stroke risk compared with aspirin.

Trial Registration

ClinicalTrials.gov Identifier: NCT03192215.

Using Epidemiological Data to Inform Clinical Trial Feasibility Assessments: A Case Study

BACKGROUND

Clinical trial enrollment and completion is challenging, with nearly half of all trials not being completed or not completed on time. In 2014, the National Institutes of Health StrokeNet in collaboration with stroke epidemiologists from GCNKSS (Greater Cincinnati/Northern Kentucky Stroke Study) began providing proposed clinical trials with formal trial feasibility assessments. Herein, we describe the process of prospective feasibility analyses using epidemiological data that can be used to improve enrollment and increase the likelihood a trial is completed.

METHODS

In 2014, DEFUSE 3 (Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke 3) trialists, National Institutes of Health StrokeNet, and stroke epidemiologists from GCNKSS collaborated to evaluate the initial inclusion/exclusion criteria for the DEFUSE 3 study. Trial criteria were discussed and an assessment was completed to evaluate the percent of the stroke population that might be eligible for the study. The DEFUSE 3 trial was stopped early with the publication of DAWN (Thrombectomy 6 to 24 Hours After Stroke With a Mismatch Between Deficit and Infarct), and the Wilcoxon rank-sum statistic was used to analyze whether the trial would have been stopped had the proposed changes not been made, following the DEFUSE 3 statistical analysis plan.

RESULTS

After initial epidemiological analysis, 2.4% of patients with acute stroke in the GCNKSS population would have been predicted to be eligible for the study. After discussion with primary investigators and modifying 4 key exclusion criteria (upper limit of age increased to 90 years, baseline modified Rankin Scale broadened to 0-2, time since last well expanded to 16 hours, and decreased lower limit of National Institutes of Health Stroke Scale score to <6), the number predicted to be eligible for the trial increased to 4%. At the time of trial conclusion, 57% of the enrolled patients qualified only by the modified criteria, and the trial was stopped at an interim analysis that demonstrated efficacy. We estimated that the Wilcoxon rank-sum value for the unadjusted predicted enrollment would not have crossed the threshold for efficacy and the trial not stopped.

CONCLUSIONS

Objectively assessing trial inclusion/exclusion criteria using a population-based resource in a collaborative and iterative process including epidemiologists can lead to improved recruitment and can increase the likelihood of successful trial completion.

National Institutes of Health StrokeNet Training Core

Background and Purpose- The National Institutes of Health (NIH) StrokeNet provides a nationwide infrastructure to advance stroke research. Capitalizing on this unique opportunity, the NIH StrokeNet Training Core (NSTC) was established with the overarching goal of enhancing the professional development of a diverse spectrum of professionals who are embedded in the stroke clinical trials network of the NIH StrokeNet. Methods- This special report provides a descriptive account of the rationale, organization, and activities of the NSTC since its inception in 2013. Current processes and their evolution over time for facilitating training of NIH StrokeNet trainees have been highlighted. Data collected for monitoring training are summarized. Outcomes data (publications and grants) collected by NSTC was supplemented by publicly available resources. Results- The NSTC comprises of cross-network faculty, trainees, and education coordinators. It helps in the development and monitoring of training programs and organizes educational and career development activities. Trainees are provided directed guidance towards their mandated research projects, including opportunities to present at the International Stroke Conference. The committee has focused on developing sustainable models of peer-to-peer interaction and cross-institutional mentorships. A total of 124 professionals (43.7% female, 10.5% underrepresented minorities) have completed training between 2013 and 2018, of whom 55% were clinical vascular neurologists. Of the total, 85% transitioned to a formal academic position and 95% were involved in stroke research post-training. Altogether, 1659 indexed publications have been authored or co-authored by NIH StrokeNet Trainees, of which 58% were published during or after their training years. Based on data from 109 trainees, 33% had submitted 72 grant proposals as principal or co-principal investigators of which 22.2% proposals have been funded. Conclusions- NSTC has provided a foundation to foster nationwide training in stroke research. Our data demonstrate strong contribution of trainees towards academic scholarship. Continued innovation in educational methodologies is required to adapt to unique training opportunities such as the NIH StrokeNet.

Type and Duration of Exercise in the SAMMPRIS Trial

BACKGROUND

Analyses from the Stenting and Aggressive Medical management for prevention of Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) trial showed that good control of vascular risk factors (systolic blood pressure, low-density lipoprotein, and exercise) was associated with fewer vascular events and exercise had the biggest impact on the outcome. We sought to determine the type and duration of exercise performed by SAMMPRIS patients during the trial.

METHODS

SAMMPRIS aggressive medical management included a telephonic lifestyle modification program, INTERVENT, that was provided free of charge to all subjects during the study. We analyzed self-reported data collected by INTERVENT on the patients' type and duration of exercise from baseline (n=394) to 3 years (n=132). We calculated the mean duration for each exercise type at each time period and then compared the change in exercise duration from baseline using paired t tests and Wilcoxon signed-rank tests.

RESULTS

Walking was the most common form of exercise at all time points, as measured by both the duration of exercise and the number of patients performing the exercise. The mean duration of walking and other aerobic activities increased significantly from baseline to all other time points.

CONCLUSIONS

The type of self-reported exercise performed by SAMMPRIS patients included mostly walking or other aerobic activity and increased significantly during follow-up.

Hemodynamic Markers in the Anterior Circulation as Predictors of Recurrent Stroke in Patients With Intracranial Stenosis

Background and Purpose- Although aggressive medical therapy was superior to stenting in the SAMMPRIS trial (Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis), the stroke rate in the medical arm was still high. The aim of this study was to determine the association between hemodynamic markers (borderzone infarct pattern and impaired collateral flow on baseline imaging) and rates of recurrent stroke in patients treated medically in SAMMPRIS. Methods- This was a post hoc analysis of patients whose qualifying event for SAMMPRIS was an infarct in the territory of a stenotic middle cerebral artery or intracranial carotid artery. Infarcts were adjudicated as involving primarily internal or cortical borderzone territories, the core middle cerebral artery territory, or perforator territories, and collateral flow was assessed according to a standard scale (American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology). Log-rank tests and χ2 tests were performed to assess associations of infarct patterns and collateral flow with rates of recurrent stroke. Results- Of 101 patients who qualified, 14 of 53 (26.4%) with borderzone infarcts, 2 of 24 (8.3%) with core middle cerebral artery infarcts, and 3 of 24 (12.5%) with perforator infarcts had a recurrent stroke in the territory (P=0.14 for comparing the 3 groups, P=0.052 for borderzone versus nonborderzone). Of 82 patients with collateral flow assessment, 30 of 43 (70%) with borderzone infarcts, 7 of 19 (37%) with core middle cerebral artery infarcts, and 11 of 20 (55%) with perforator infarcts had impaired collateral flow distal to the stenosis (P=0.049). Patients with borderzone infarcts and impaired collateral flow had the highest risk of recurrent stroke (37%). Conclusions- Borderzone infarcts and impaired collateral flow identify a subgroup of patients with intracranial stenosis who are at particularly high risk of recurrent stroke on medical treatment. Clinical Trial Registration- URL: https://www.clinicaltrials.gov. Unique identifier: NCT00576693.

Relationship between Risk Factor Control and Compliance with a Lifestyle Modification Program in the Stenting Aggressive Medical Management for Prevention of Recurrent Stroke in Intracranial Stenosis Trial

BACKGROUND

Lifestyle modification programs have improved the achievement of risk factor targets in a variety of clinical settings, including patients who have previously suffered a stroke or transient ischemic attack and those with multiple risk factors. Stenting Aggressive Medical Management for Prevention of Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) was the first vascular disease prevention trial to provide a commercially available lifestyle modification program to enhance risk factor control. We sought to determine the relationship between compliance with this program and risk factor control in SAMMPRIS.

METHODS

SAMMPRIS aggressive medical management included a telephonic lifestyle modification program provided free of charge to all subjects (n = 451) during their participation in the study. Subjects with fewer than 3 expected lifestyle-coaching calls were excluded from these analyses. Compliant subjects (n = 201) had  greater than or equal to 78.5% of calls (median % of completed/expected calls). Noncompliant subjects (n = 200) had less than 78.5% of calls or refused to participate. Mean risk factor values or % in-target for each risk factor was compared between compliant versus noncompliant subjects, using t tests and chi-square tests. Risk factor changes from baseline to follow-up were compared between the groups to account for baseline differences.

RESULTS

Compliant subjects had better risk factor control throughout follow-up for low-density lipoprotein, systolic blood pressure (SBP), hemoglobin A1c (HgA1c), non-high-density lipoprotein, nonsmoking, and exercise than noncompliant subjects, but there was no difference for body mass index. After adjusting for baseline differences between the groups, compliant subjects had a greater change from baseline than noncompliant subjects for SBP did at 24 months and HgA1c at 6 months.

CONCLUSION

SAMMPRIS subjects who were compliant with the lifestyle modification program had better risk factor control during the study for almost all risk factors.

Observed Cost and Variations in Short Term Cost-Effectiveness of Therapy for Ischemic Stroke in Interventional Management of Stroke (IMS) III

Background

Examination of linked data on patient outcomes and cost of care may help identify areas where stroke care can be improved. We report on the association between variations in stroke severity, patient outcomes, cost, and treatment patterns observed over the acute hospital stay and through the 12‐month follow‐up for subjects receiving endovascular therapy compared to intravenous tissue plasminogen activator alone in the IMS (Interventional Management of Stroke) III Trial.

Methods and Results

Prospective data collected for a prespecified economic analysis of the trial were used. Data included hospital billing records for the initial stroke admission and subsequent detailed resource use after the acute hospitalization collected at 3, 6, 9, and 12 months. Cost of follow‐up care varied 6‐fold for patients in the lowest (0–1) and highest (20+) National Institutes of Health Stroke Scale category at 5 days, and by modified Rankin Scale at 3 months. The kind of resources used postdischarge also varied between treatment groups. Incremental short‐term cost‐effectiveness ratios varied greatly when treatments were compared for patient subgroups. Patient subgroups predefined by stroke severity had incremental cost‐effectiveness ratios of $97 303/quality‐adjusted life year (severe stroke) and $3 187 805/quality‐adjusted life year (moderately severe stroke).

Conclusions

Detailed economic and resource utilization data from IMS III provide powerful evidence for the large effect that patient outcome has on the economic value of medical and endovascular reperfusion therapies. These data can be used to inform process improvements for stroke care and to estimate the cost‐effectiveness of endovascular therapy in the US health system for stroke intervention trials.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Registration number: NCT00359424.

Nonprocedural Symptomatic Infarction and In-Stent Restenosis After Intracranial Angioplasty and Stenting in the SAMMPRIS Trial (Stenting and Aggressive Medical Management for the Prevention of Recurrent Stroke in Intracranial Stenosis)

BACKGROUND AND PURPOSE

The purpose of this study was to investigate the frequency of symptomatic in-stent restenosis (ISR) and its contribution to nonprocedural symptomatic infarction in the SAMMPRIS trial (Stenting and Aggressive Medical Management for the Prevention of Recurrent Stroke in Intracranial Stenosis).

METHODS

Patients without a periprocedural primary end point were followed up to determine the occurrence of any of the following events: ischemic stroke, cerebral infarct with temporary signs, or transient ischemic attack in the territory of the stented artery. Vascular imaging performed after these events was reviewed for ISR. Annual rates for symptomatic ISR were calculated using Kaplan-Meier estimates.

RESULTS

Of 183 patients in the stenting group without a periprocedural primary end point, 27 (14.8%) had a symptomatic infarction (stroke or cerebral infarct with temporary signs) and 16 (8.7%) had transient ischemic attack alone in the territory during a median follow-up of 35.0 months. Of the 27 patients with infarctions, 17 (9.3%) had an ischemic stroke and 10 (5.5%) had a cerebral infarct with temporary signs alone. Adequate vascular imaging to evaluate ISR was available in 24 patients with infarctions (showing ISR in 16 [66.7%]) and in 10 patients with transient ischemic attack alone (showing ISR in 8 [80%]). The 1-, 2-, and 3-year rates (with 95% confidence limits) for symptomatic ISR in the SAMMPRIS stent cohort were 9.6% (6.1%-14.9%), 11.3% (7.5%-17.0%), and 14.0% (9.6%-20.2%), respectively.

CONCLUSIONS

Symptomatic ISR occurred in at least 1 of 7 patients in SAMMPRIS by 3 years of follow-up and was likely responsible for the majority of nonprocedural cerebral infarctions.

CLINICAL TRIAL REGISTRATION

URL: https://clinicaltrials.gov. Unique identifier: NCT00576693.

Relationship between risk factor control and vascular events in the SAMMPRIS trial

OBJECTIVE

The Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) study is the first stroke prevention trial to include protocol-driven intensive management of multiple risk factors. In this prespecified analysis, we aimed to investigate the relationship between risk factor control during follow-up and outcome of patients in the medical arm of SAMMPRIS.

METHODS

Data from SAMMPRIS participants in the medical arm (n = 227) were analyzed. Risk factors were recorded at baseline, 30 days, 4 months, and then every 4 months for a mean follow-up of 32 months. For each patient, values for all risk factor measures were averaged and dichotomized as in or out of target.

RESULTS

Participants who were out of target for systolic blood pressure and physical activity, as well as those with higher mean low-density lipoprotein cholesterol and non-high-density lipoprotein, were more likely to have a recurrent vascular event (stroke, myocardial infarction, or vascular death) at 3 years compared to those who had good risk factor control. In the multivariable analysis, greater physical activity decreased the likelihood of a recurrent stroke, myocardial infarction, or vascular death (odds ratio 0.6, confidence interval 0.4-0.8).

CONCLUSIONS

Raised blood pressure, cholesterol, and physical inactivity should be aggressively treated in patients with intracranial atherosclerosis to prevent future vascular events. Physical activity, which has not received attention in stroke prevention trials, was the strongest predictor of a good outcome in the medical arm in SAMMPRIS.

CLINICALTRIALSGOV IDENTIFIER

NCT00576693.

Impact of the New American Heart Association/American Stroke Association Definition of Stroke on the Results of the Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis Trial

BACKGROUND

An American Heart Association/American Stroke Association (AHA/ASA) writing committee has recently recommended that tissue evidence of cerebral infarction associated with temporary symptoms (CITS) lasting <24 hours should be considered a stroke. We analyzed the impact of considering CITS as equivalent to stroke on the results of the Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) trial.

METHODS

We compared outcomes in the medical (n = 227) and stenting (n = 224) groups in SAMMPRIS using the following primary end point (new components in bold): any stroke, CITS, or death within 30 days after enrollment or within 30 days after a revascularization procedure for the qualifying lesion during follow-up; or ischemic stroke or CITS in the territory of the qualifying artery beyond 30 days. We also compared the use of brain magnetic resonance imaging (MRI) after transient ischemic attacks (TIAs) in both treatment groups.

RESULTS

By considering CITS as equivalent to stroke, the number of primary end points increased from 34 to 43 in the medical group and from 52 to 66 in the stenting group of SAMMPRIS. The Kaplan-Meier curves for the primary end points in the 2 groups were significantly different (P = .009). The percentage of patients with reported TIAs who underwent brain MRI was 69% in the medical group and 61% in the stenting group (P = .40).

CONCLUSION

Using the AHA/ASA definition of stroke resulted in a substantially higher primary end point rate in both treatment groups and an even higher benefit from medical therapy over stenting than originally shown in SAMMPRIS. The higher rate of CITS in the stenting group was not due to ascertainment bias.

Frequency, Risk Factors, and Outcome of Coexistent Small Vessel Disease and Intracranial Arterial Stenosis: Results From the Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) Trial

IMPORTANCE

Intracranial arterial stenosis (ICAS) and small vessel disease (SVD) may coexist. There are limited data on the frequency and risk factors for coexistent SVD and the effect of SVD on stroke recurrence in patients receiving medical treatment for ICAS.

OBJECTIVE

To investigate the frequency and risk factors for SVD and the effect of SVD on stroke recurrence in patients with ICAS.

DESIGN, SETTING, AND PARTICIPANTS

A post hoc analysis of the Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) study, a prospective, multicenter clinical trial. Among 451 participants, 313 (69.4%) had baseline brain magnetic resonance imaging scans read centrally for SVD that was defined by any of the following: old lacunar infarction, grade 2 to 3 on the Fazekas scale (for high-grade white matter hyperintensities), or microbleeds. Patient enrollment in SAMMPRIS began November 25, 2008, and follow-up ended on April 30, 2013. Data analysis for the present study was performed from May 13, 2014, to July 29, 2015.

MAIN OUTCOMES AND MEASURES

Risk factors in patients with vs without SVD and the association between SVD and other baseline risk factors with any ischemic stroke and ischemic stroke in the territory of the stenotic artery determined using proportional hazards regression.

RESULTS

Of 313 patients, 155 individuals (49.5%) had SVD noted on baseline magnetic resonance imaging. Variables that were significantly higher in patients with SVD, reported as mean (SD), included age, 63.5 (10.5) years (P < .001), systolic blood pressure, 149 (22) mm Hg (P < .001), glucose level, 130 (50) mg/dL (P = .03), and lower Montreal Cognitive Assessment scores (median, ≥24 [interquartile range, 20-26]; P = .02).Other significant variables were the number of patients with diabetes mellitus (88 of 155 [56.8%]; P = .003), coronary artery disease (46 [29.7%]; P = .004), stroke before the qualifying event (59 [38.1%]; P < .001), old infarct in the territory of the stenotic intracranial artery (88 [56.8%]; P < .001), and receiving antithrombotic therapy at the time of the qualifying event (109 [70.3%]; P = .005). The association between SVD and any ischemic stroke was nearly significant in the direction of a higher risk (18 [23.7%]); P = .07) for patients with SVD. On bivariate analysis, SVD was not associated with an increased risk on multivariable analyses (hazard ratio, 1.7 [95% CI, 0.8-3.8]; P = .20). In addition, SVD was not associated with an increased risk of stroke in the territory on either bivariate or multivariable analyses.

CONCLUSIONS AND RELEVANCE

Although SVD is common in patients with ICAS, the presence of SVD on baseline magnetic resonance imaging is not independently associated with an increased risk of stroke in patients with ICAS.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00576693.

Does the Stenting Versus Aggressive Medical Therapy Trial Support Stenting for Subgroups With Intracranial Stenosis?

BACKGROUND AND PURPOSE

Although the Stenting Versus Aggressive Medical Therapy for Intracranial Arterial Stenosis (SAMMPRIS) trial showed that medical therapy alone was superior to stenting plus medical therapy for preventing recurrent strokes in patients with symptomatic intracranial stenosis, we determined whether SAMMPRIS supported the use of stenting in any subpopulations of patients with symptomatic intracranial arterial stenosis.

METHODS

The primary outcome, 30-day stroke and death and later strokes in the territory of the qualifying artery, was compared in those with and without baseline factors in the 2 treatment arms, percutaneous transluminal angioplasty and stenting (PTAS) plus aggressive medical therapy versus aggressive medical therapy alone. Baseline factors included sex, age, race, diabetes mellitus, hypertension, lipid disorder, smoking status, type of qualifying event, qualifying event hypoperfusion symptoms, use of antithrombotic or proton pump inhibitor at baseline, days to enrollment, old infarcts in the same territory, percent stenosis, other artery stenosis, and location of the symptomatic artery.

RESULTS

A total of 451 patients were enrolled, 227 randomized to aggressive medical therapy and 224 to PTAS. Of all variables evaluated, the observed 2-year event rates were higher with PTAS than with aggressive medical therapy in the vast majority and the interaction with treatment was not statistically significant for any of the factors.

CONCLUSIONS

The SAMMPRIS results do not provide evidence to support the use of PTAS using the Wingspan stent system compared with medical treatment in any examined subpopulation of patients with symptomatic intracranial stenosis, including those with qualifying event hypoperfusion symptoms.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00576693.

Endovascular Therapy Is Effective and Safe for Patients With Severe Ischemic Stroke: Pooled Analysis of Interventional Management of Stroke III and Multicenter Randomized Clinical Trial of Endovascular Therapy for Acute Ischemic Stroke in the Netherlands Data

BACKGROUND AND PURPOSE

We assessed the effect of endovascular treatment in acute ischemic stroke patients with severe neurological deficit (National Institutes of Health Stroke Scale score, ≥20) after a prespecified analysis plan.

METHODS

The pooled analysis of the Interventional Management of Stroke III (IMS III) and Multicenter Randomized Clinical Trial of Endovascular Therapy for Acute Ischemic Stroke in the Netherlands (MR CLEAN) trials included participants with an National Institutes of Health Stroke Scale score of ≥20 before intravenous tissue-type plasminogen activator (tPA) treatment (IMS III) or randomization (MR CLEAN) who were treated with intravenous tPA ≤3 hours of stroke onset. Our hypothesis was that participants with severe stroke randomized to endovascular therapy after intravenous tPA would have improved 90-day outcome (distribution of modified Rankin Scale scores), when compared with those who received intravenous tPA alone.

RESULTS

Among 342 participants in the pooled analysis (194 from IMS III and 148 from MR CLEAN), an ordinal logistic regression model showed that the endovascular group had superior 90-day outcome compared with the intravenous tPA group (adjusted odds ratio, 1.78; 95% confidence interval, 1.20-2.66). In the logistic regression model of the dichotomous outcome (modified Rankin Scale score, 0-2, or functional independence), the endovascular group had superior outcomes (adjusted odds ratio, 1.97; 95% confidence interval, 1.09-3.56). Functional independence (modified Rankin Scale score, ≤2) at 90 days was 25% in the endovascular group when compared with 14% in the intravenous tPA group.

CONCLUSIONS

Endovascular therapy after intravenous tPA within 3 hours of symptom onset improves functional outcome at 90 days after severe ischemic stroke.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00359424 (IMS III) and ISRCTN10888758 (MR CLEAN).

Do Patient Characteristics Explain the Differences in Outcome Between Medically Treated Patients in SAMMPRIS and WASID?

BACKGROUND AND PURPOSE

The Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) medical group had a much lower primary end point rate than predicted from the preceding Warfarin Aspirin Symptomatic Intracranial Disease (WASID) trial. This result has been attributed to the aggressive medical therapy used in SAMMPRIS, but an alternative hypothesis is that SAMMPRIS patients were at lower risk. We undertook analyses to evaluate these competing hypotheses.

METHODS

Using proportional hazards regression, we compared the SAMMPRIS primary end point between SAMMPRIS medical patients and WASID patients meeting the same qualifying criteria adjusted for confounding baseline characteristics.

RESULTS

The unadjusted comparison of the SAMMPRIS primary end point showed a significantly higher risk for WASID patients (P=0.009, logrank test) with 12 month Kaplan-Meier estimates of 21.9% in WASID and 12.6% in SAMMPRIS and hazard ratio 1.9 (95% confidence interval =1.2-3.0). The analyses identified the following confounding factors that varied between the studies and that conferred a higher risk: lack of statin use at enrollment (hazard ratio =1.8, 95% confidence interval =1.1-2.9, P=0.027) that was more prevalent among WASID patients (39% versus 14%, P<0.0001) and prior infarcts in the territory of the symptomatic vessel (hazard ratio =1.8, 95% confidence interval =1.1-2.9, P=0.023) that was more prevalent among SAMMPRIS patients (34% versus 22%, P=0.015).The hazard ratio for WASID versus SAMMPRIS adjusted for these 2 characteristics was 1.9 (95% confidence interval =1.1-3.2).

CONCLUSIONS

After adjustment for confounding baseline characteristics, WASID patients had an almost 2-fold higher risk of the SAMMPRIS primary end point, which supports the hypothesis that the lower rate of the primary end point in the medical arm of SAMMPRIS compared with WASID patients was as a result of the aggressive medical management used in SAMMPRIS.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00576693.

Twelve-Month Clinical and Quality-of-Life Outcomes in the Interventional Management of Stroke III Trial

BACKGROUND AND PURPOSE

Randomized trials have indicated a benefit for endovascular therapy in appropriately selected stroke patients at 3 months, but data regarding outcomes at 12 months are currently lacking.

METHODS

We compared functional and quality-of-life outcomes at 12 months overall and by stroke severity in stroke patients treated with intravenous tissue-type plasminogen activator followed by endovascular treatment as compared with intravenous tissue-type plasminogen activator alone in the Interventional Management of Stroke III Trial. The key outcome measures were a modified Rankin Scale score ≤2 (functional independence) and the Euro-QoL EQ-5D, a health-related quality-of-life measure.

RESULTS

656 subjects with moderate-to-severe stroke (National Institutes of Health Stroke Scale ≥8) were enrolled at 58 centers in the United States (41 sites), Canada (7), Australia (4), and Europe (6). There was an interaction between treatment group and stroke severity in the repeated measures analysis of modified Rankin Scale ≤2 outcome (P=0.039). In the 204 participants with severe stroke (National Institutes of Health Stroke Scale ≥20), a greater proportion of the endovascular group had a modified Rankin Scale ≤2 (32.5%) at 12 months as compared with the intravenous tissue-type plasminogen activator group (18.6%, P=0.037); no difference was seen for the 452 participants with moderately severe strokes (55.6% versus 57.7%). In participants with severe stroke, the endovascular group had 35.2 (95% confidence interval: 2.1, 73.3) more quality-adjusted-days over 12 months as compared with intravenous tissue-type plasminogen activator alone.

CONCLUSIONS

Endovascular therapy improves functional outcome and health-related quality-of-life at 12 months after severe ischemic stroke.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00359424.

Outcome in patients previously on antithrombotic therapy in the SAMMPRIS trial: subgroup analysis

BACKGROUND AND PURPOSE

Stenting has been used as a rescue therapy in patients with intracranial arterial stenosis and a transient ischemic attack or stroke when on antithrombotic therapy (AT). We determined whether the stenting versus aggressive medical therapy for intracranial arterial stenosis (SAMMPRIS) trial supported this approach by comparing the treatments within subgroups of patients whose qualifying event (QE) occurred on versus off of AT.

METHODS

The primary outcome, 30-day stroke and death and later strokes in the territory of the qualifying artery, was compared between (1) percutaneous transluminal angioplasty and stenting plus aggressive medical therapy (PTAS) versus aggressive medical management therapy alone (AMM) for patients whose QE occurred on versus off AT and between (2) patients whose QE occurred on versus off AT separately for the treatment groups.

RESULTS

Among the 284/451 (63%) patients who had their QE on AT, the 2-year primary end point rates were 15.6% for those randomized to AMM (n=140) and 21.6% for PTAS (n=144; P=0.043, log-rank test). In the 167 patients not on AT, the 2-year primary end point rates were 11.6% for AMM (n=87) and 18.8% for PTAS (n=80; P=0.31, log-rank test). Within both treatment groups, there was no difference in the time to the primary end point between patients who were on or off AT (AMM, P=0.96; PTAS, P=0.52; log-rank test).

CONCLUSIONS

SAMMPRIS results indicate that the benefit of AMM over PTAS is similar in patients on versus off AT at the QE and that failure of AT is not a predictor of increased risk of a primary end point.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT00576693.

Abstract W P381: Type and Duration of Exercise in the SAMMPRIS Trial

Background: Previous analyses of SAMMPRIS trial data showed that good risk factor control resulted in a significant reduction in the risk of vascular events (stroke, MI, and vascular death), with exercise as the most important predictor of good outcome. We sought to determine the type and duration of exercise that SAMMPRIS patients reported during the trial.

Methods: In SAMMPRIS, 451 patients with recent TIA or stroke attributed to 70-99% intracranial stenosis were randomized to aggressive medical management (AMM) alone or percutaneous transluminal angioplasty and stenting plus AMM at 50 USA sites. AMM included a telephonic lifestyle modification program, INTERVENT, that was provided free of charge to all subjects during their participation in the study. We analyzed self-reported data collected by INTERVENT on the patients’ type and duration of exercise from baseline (n= 394) to 4 years (n=34). We calculated the mean duration for each exercise type at each time period and then compared the change in exercise duration from baseline using paired t-tests and Wilcoxon signed rank tests.

Results: Data from subjects who completed the INTERVENT questionnaires were included in these analyses. As shown in the Figure, walking was the most common form of exercise at all time points, as measured by both the duration of exercise and the number of patients performing the exercise. The mean duration of walking and other aerobic activities increased significantly from baseline to all other time points.

Conclusions: The type of self-reported exercise performed by SAMMPRIS patients included mostly walking or other aerobic activity and increased significantly during follow-up. Given that exercise was protective against recurrent vascular events, future secondary prevention stroke trials should encourage and monitor exercise participation and neurologists should encourage physical activity in clinical practice.

Abstract T MP35: Frequency, Risk Factors, and Impact of Coexistent Small Vessel Disease in the SAMMPRIS Trial

Background: Intracranial atherosclerotic stenosis (ICAS) and small vessel disease (SVD) may coexist. We investigated the frequency and risk factors for SVD in SAMMPRIS patients and the impact of SVD on stroke recurrence in the medical arm of the trial.

Methods: Of 451 patients enrolled in SAMMPRIS, 313 had baseline brain MRIs read centrally for SVD. SVD was defined by any of the following: old lacunar infarction, Fazekas score of 2-3 for white matter hyperintensities, or microbleeds. We compared risk factors in patients with vs. without SVD using Fisher’s exact test (for percentages), independent groups t test (for means) or Wilcoxon rank sum test (for medians), and compared the survival curves of patients with vs. without SVD in the medical arm for ischemic stroke in the territory of the stenotic artery and any ischemic stroke using the logrank test.

Results: Of the 313 patients, 161 (51.4%) had SVD on the baseline MRI. Variables that were significantly (p<0.05) higher in patients with SVD were age, diabetes, lipid disorder, baseline SBP, coronary disease, and old infarct in the territory. The Kaplan-Meier curves in the figure show that patients with SVD were at significantly higher risk of any ischemic stroke (p = 0.048) but not stroke in the territory (p = 0.10) compared with patients without SVD.

Conclusion: SVD in patients with ICAS is common, especially in patients who are older, diabetic, hyperlipidemic, and have higher SBP. Patients with ICAS and coexistent SVD are at higher risk of any ischemic stroke but may not be at higher risk for stroke in the territory.

Abstract W P113: Prolonged Use of Clopidogrel and Aspirin and Stroke Risk in Intracranial Stenosis in SAMMPRIS

Background: In the SAMMPRIS trial, the use of combination aspirin and clopidogrel for 90 days after enrollment could be one reason that the outcome of patients in the medical arm was better than expected. The SAMMPRIS protocol required stopping clopidogrel after 90 days unless the patient had a non-neurological indication for continued use. We sought to compare outcomes in patients on vs. off clopidogrel beyond 90 days.

Methods: For patients who did not have a primary endpoint within 90 days after enrollment (n = 397), we compared baseline features (t and Fisher’s exact tests), survival curves for the primary endpoint beyond 90 days after enrollment (the logrank test), and major hemorrhages (Fisher’s exact test) in patients on vs. off clopidogrel in the medical arm and stenting arms.

Results: In the medical and stenting groups combined, baseline factors that were significantly (p<0.05) different between those on vs. off clopidogrel beyond 90 days (all higher in on clopidogrel group) were: age, diabetes, lipid disorder, coronary disease, SBP, and on antithrombotic agent at qualifying event. The table shows the primary endpoints and major hemorrhages in patients on vs. off clopidogrel in both treatment groups.

Conclusion: This analysis, which was underpowered to detect even very large differences in event rates, suggests that prolonged use of clopidogrel plus aspirin may lower the risk of stroke in medically treated patients with intracranial stenosis, but increase the risk of major hemorrhage. Further studies with higher statistical power are needed to test this hypothesis.

Abstract W P382: Cognitive Outcome in SAMMPRIS: Medical Therapy vs. Stenting

Background: It has been hypothesized that revascularization of stenotic cerebral arteries may improve cognitive outcome by increasing cerebral perfusion. We sought to compare cognitive outcome in patients treated with percutaneous angioplasty and stenting (PTAS) and aggressive medical management (AMM) vs. AMM alone in the SAMMPRIS Trial.

Methods: In SAMMPRIS, 451 patients with recent TIA or stroke attributed to 70%-99% intracranial stenosis were randomized to PTAS plus AMM or AMM alone. Patients with stroke as the qualifying event who had a NIHSS indicating aphasia or neglect were excluded from these analyses. Patients with any ischemic stroke, cerebral infarct with temporary signs (CITS), or ICH during follow-up were excluded from subsequent follow-up visit analyses. The Montreal Cognitive Assessment (MoCA) score was used to assess cognition at baseline, 4 months, 12 months, and closeout (mean 3.05 years in AMM group and 3.12 years in PTAS group). Cognitive impairment was defined as MoCA <26. Mean MoCA scores and the percentage of patients with cognitive impairment were compared between treatment groups at each time point using t-tests and Chi-square tests. Differences in MoCA means from baseline to follow-up time points were compared using mixed model repeated measures ANOVA and Tukey-Kramer tests.

Results: As shown in the Figure, there were no significant differences between the treatment groups for mean MoCA at any time point. There were significant improvements in mean MoCA from baseline to 4 months, 12 months, and closeout in both groups. The percentage of patients with cognitive impairment in the AMM vs. PTAS groups were not significantly different at baseline (53 vs. 56%), 4 months (38 vs. 44%), 12 months (42 vs. 40%), and closeout (43 vs. 39%).

Conclusions: Revascularization did not provide any additional cognitive benefit over AMM alone in SAMMPRIS even after excluding patients who had cerebral infarction or ICH during follow-up.

Very early administration of progesterone for acute traumatic brain injury

BACKGROUND

Traumatic brain injury (TBI) is a major cause of death and disability worldwide. Progesterone has been shown to improve neurologic outcome in multiple experimental models and two early-phase trials involving patients with TBI.

METHODS

We conducted a double-blind, multicenter clinical trial in which patients with severe, moderate-to-severe, or moderate acute TBI (Glasgow Coma Scale score of 4 to 12, on a scale from 3 to 15, with lower scores indicating a lower level of consciousness) were randomly assigned to intravenous progesterone or placebo, with the study treatment initiated within 4 hours after injury and administered for a total of 96 hours. Efficacy was defined as an increase of 10 percentage points in the proportion of patients with a favorable outcome, as determined with the use of the stratified dichotomy of the Extended Glasgow Outcome Scale score at 6 months after injury. Secondary outcomes included mortality and the Disability Rating Scale score.

RESULTS

A total of 882 of the planned sample of 1140 patients underwent randomization before the trial was stopped for futility with respect to the primary outcome. The study groups were similar with regard to baseline characteristics; the median age of the patients was 35 years, 73.7% were men, 15.2% were black, and the mean Injury Severity Score was 24.4 (on a scale from 0 to 75, with higher scores indicating greater severity). The most frequent mechanism of injury was a motor vehicle accident. There was no significant difference between the progesterone group and the placebo group in the proportion of patients with a favorable outcome (relative benefit of progesterone, 0.95; 95% confidence interval [CI], 0.85 to 1.06; P=0.35). Phlebitis or thrombophlebitis was more frequent in the progesterone group than in the placebo group (relative risk, 3.03; CI, 1.96 to 4.66). There were no significant differences in the other prespecified safety outcomes.

CONCLUSIONS

This clinical trial did not show a benefit of progesterone over placebo in the improvement of outcomes in patients with acute TBI. (Funded by the National Institute of Neurological Disorders and Stroke and others; PROTECT III ClinicalTrials.gov number, NCT00822900.).

Evolution of practice during the Interventional Management of Stroke III Trial and implications for ongoing trials

BACKGROUND AND PURPOSE

We explored changes in the patient population and practice of endovascular therapy during the course of the Interventional Management of Stroke (IMS) III Trial.

METHODS

Changes in baseline characteristics, use of baseline CT angiography, treatment times and specifics, and outcomes were compared between the first 4 protocols and the fifth and final protocol.

RESULTS

Compared with subjects treated in the first 4 protocol versions (n=610), subjects treated in fifth and final protocol (n=46) were older (75 versus 68 years, P<0.0002) and less likely to have a pretreatment Rankin of 0 (76% versus 89%, P=0.01), were more likely to have a pretreatment CT angiography (65% versus 45%, P=0.009), had quicker median times in the endovascular arm from onset to start of intra-arterial therapy (209 versus 250 minutes, P=0.002) and to reperfusion (269 versus 344 minutes, P<0.0001), had a higher mean dose of total tissue-type plasminogen activator in the endovascular arm (74.0 versus 63.7 mg, P<0.0001), and were less likely to receive intra-arterial tissue-type plasminogen activator as part of the endovascular procedure (16% versus 44%, P=0.015). There were no significant differences in functional and safety outcomes between subjects treated in the 2 treatments arms in either the first 4 protocols or fifth protocol although the small sample size in the fifth protocol provided limited power.

CONCLUSIONS

Endovascular technology and diagnostic approaches to acute stroke patients changed substantially during the IMS III Trial. Efforts to decrease the time to delivery of endovascular therapy were successful.

Aggressive medical treatment with or without stenting in high-risk patients with intracranial artery stenosis (SAMMPRIS): the final results of a randomised trial

BACKGROUND

Early results of the Stenting and Aggressive Medical Management for Preventing Recurrent stroke in Intracranial Stenosis trial showed that, by 30 days, 33 (14·7%) of 224 patients in the stenting group and 13 (5·8%) of 227 patients in the medical group had died or had a stroke (percentages are product limit estimates), but provided insufficient data to establish whether stenting offered any longer-term benefit. Here we report the long-term outcome of patients in this trial.

METHODS

We randomly assigned (1:1, stratified by centre with randomly permuted block sizes) 451 patients with recent transient ischaemic attack or stroke related to 70-99% stenosis of a major intracranial artery to aggressive medical management (antiplatelet therapy, intensive management of vascular risk factors, and a lifestyle-modification programme) or aggressive medical management plus stenting with the Wingspan stent. The primary endpoint was any of the following: stroke or death within 30 days after enrolment, ischaemic stroke in the territory of the qualifying artery beyond 30 days of enrolment, or stroke or death within 30 days after a revascularisation procedure of the qualifying lesion during follow-up. Primary endpoint analysis of between-group differences with log-rank test was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT 00576693.

FINDINGS

During a median follow-up of 32·4 months, 34 (15%) of 227 patients in the medical group and 52 (23%) of 224 patients in the stenting group had a primary endpoint event. The cumulative probability of the primary endpoints was smaller in the medical group versus the percutaneous transluminal angioplasty and stenting (PTAS) group (p=0·0252). Beyond 30 days, 21 (10%) of 210 patients in the medical group and 19 (10%) of 191 patients in the stenting group had a primary endpoint. The absolute differences in the primary endpoint rates between the two groups were 7·1% at year 1 (95% CI 0·2 to 13·8%; p=0·0428), 6·5% at year 2 (-0·5 to 13·5%; p=0·07) and 9·0% at year 3 (1·5 to 16·5%; p=0·0193). The occurrence of the following adverse events was higher in the PTAS group than in the medical group: any stroke (59 [26%] of 224 patients vs 42 [19%] of 227 patients; p=0·0468) and major haemorrhage (29 [13%]of 224 patients vs 10 [4%] of 227 patients; p=0·0009).

INTERPRETATION

The early benefit of aggressive medical management over stenting with the Wingspan stent for high-risk patients with intracranial stenosis persists over extended follow-up. Our findings lend support to the use of aggressive medical management rather than PTAS with the Wingspan system in high-risk patients with atherosclerotic intracranial arterial stenosis.

FUNDING

National Institute of Neurological Disorders and Stroke (NINDS) and others.

Mechanisms of stroke after intracranial angioplasty and stenting in the SAMMPRIS trial

BACKGROUND

Enrollment in the stenting and aggressive medical management for the prevention of stroke in intracranial stenosis (SAMMPRIS) trial was halted owing to higher-than-expected 30-day stroke rates in the stenting arm. Improvement in periprocedural stroke rates from angioplasty and stenting for intracranial atherosclerotic disease (ICAD) requires an understanding of the mechanisms of these events.

OBJECTIVE

To identify the types and mechanisms of periprocedural stroke after angioplasty and stenting for ICAD.

METHODS

Patients who experienced a hemorrhagic or ischemic stroke or a cerebral infarct with temporary signs within 30 days of attempted angioplasty and stenting in SAMMPRIS were identified. Study records, including case report forms, procedure notes, and imaging were reviewed. Strokes were categorized as ischemic or hemorrhagic. Ischemic strokes were categorized as perforator territory, distal embolic, or delayed stent thrombosis. Hemorrhagic strokes were categorized as subarachnoid or intraparenchymal. Causes of hemorrhage (wire perforation, vessel rupture) were recorded.

RESULTS

Three patients had an ischemic stroke after diagnostic angiography. Two of these strokes were unrelated to the procedure. Twenty-one patients had an ischemic stroke (n = 19) or cerebral infarct with temporary signs (n = 2) within 30 days of angioplasty and stenting. Most (n = 15) were perforator territory and many of these occurred after angiographically successful angioplasty and stenting of the basilar artery (n = 8). Six patients experienced a subarachnoid hemorrhage (3 from wire perforation) and 7 had a delayed intraparenchymal hemorrhage.

CONCLUSION

Efforts at reducing complications from angioplasty and stenting for ICAD must focus on reducing the risks of regional perforator infarction, delayed intraparenchymal hemorrhage, and wire perforation.

An updated definition of stroke for the 21st century: a statement for healthcare professionals from the American Heart Association/American Stroke Association

Despite the global impact and advances in understanding the pathophysiology of cerebrovascular diseases, the term "stroke" is not consistently defined in clinical practice, in clinical research, or in assessments of the public health. The classic definition is mainly clinical and does not account for advances in science and technology. The Stroke Council of the American Heart Association/American Stroke Association convened a writing group to develop an expert consensus document for an updated definition of stroke for the 21st century. Central nervous system infarction is defined as brain, spinal cord, or retinal cell death attributable to ischemia, based on neuropathological, neuroimaging, and/or clinical evidence of permanent injury. Central nervous system infarction occurs over a clinical spectrum: Ischemic stroke specifically refers to central nervous system infarction accompanied by overt symptoms, while silent infarction by definition causes no known symptoms. Stroke also broadly includes intracerebral hemorrhage and subarachnoid hemorrhage. The updated definition of stroke incorporates clinical and tissue criteria and can be incorporated into practice, research, and assessments of the public health.

Endovascular therapy after intravenous t-PA versus t-PA alone for stroke

BACKGROUND

Endovascular therapy is increasingly used after the administration of intravenous tissue plasminogen activator (t-PA) for patients with moderate-to-severe acute ischemic stroke, but whether a combined approach is more effective than intravenous t-PA alone is uncertain.

METHODS

We randomly assigned eligible patients who had received intravenous t-PA within 3 hours after symptom onset to receive additional endovascular therapy or intravenous t-PA alone, in a 2:1 ratio. The primary outcome measure was a modified Rankin scale score of 2 or less (indicating functional independence) at 90 days (scores range from 0 to 6, with higher scores indicating greater disability).

RESULTS

The study was stopped early because of futility after 656 participants had undergone randomization (434 patients to endovascular therapy and 222 to intravenous t-PA alone). The proportion of participants with a modified Rankin score of 2 or less at 90 days did not differ significantly according to treatment (40.8% with endovascular therapy and 38.7% with intravenous t-PA; absolute adjusted difference, 1.5 percentage points; 95% confidence interval [CI], -6.1 to 9.1, with adjustment for the National Institutes of Health Stroke Scale [NIHSS] score [8-19, indicating moderately severe stroke, or ≥20, indicating severe stroke]), nor were there significant differences for the predefined subgroups of patients with an NIHSS score of 20 or higher (6.8 percentage points; 95% CI, -4.4 to 18.1) and those with a score of 19 or lower (-1.0 percentage point; 95% CI, -10.8 to 8.8). Findings in the endovascular-therapy and intravenous t-PA groups were similar for mortality at 90 days (19.1% and 21.6%, respectively; P=0.52) and the proportion of patients with symptomatic intracerebral hemorrhage within 30 hours after initiation of t-PA (6.2% and 5.9%, respectively; P=0.83).

CONCLUSIONS

The trial showed similar safety outcomes and no significant difference in functional independence with endovascular therapy after intravenous t-PA, as compared with intravenous t-PA alone. (Funded by the National Institutes of Health and others; ClinicalTrials.gov number, NCT00359424.).

Detailed analysis of periprocedural strokes in patients undergoing intracranial stenting in Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS)

BACKGROUND AND PURPOSE

Enrollment in the Stenting and Aggressive Medical Management for Preventing Recurrent stroke in Intracranial Stenosis (SAMMPRIS) trial was halted due to the high risk of stroke or death within 30 days of enrollment in the percutaneous transluminal angioplasty and stenting arm relative to the medical arm. This analysis focuses on the patient and procedural factors that may have been associated with periprocedural cerebrovascular events in the trial.

METHODS

Bivariate and multivariate analyses were performed to evaluate whether patient and procedural variables were associated with cerebral ischemic or hemorrhagic events occurring within 30 days of enrollment (termed periprocedural) in the percutaneous transluminal angioplasty and stenting arm.

RESULTS

Of 224 patients randomized to percutaneous transluminal angioplasty and stenting, 213 underwent angioplasty alone (n=5) or with stenting (n=208). Of these, 13 had hemorrhagic strokes (7 parenchymal, 6 subarachnoid), 19 had ischemic stroke, and 2 had cerebral infarcts with temporary signs within the periprocedural period. Ischemic events were categorized as perforator occlusions (13), embolic (4), mixed perforator and embolic (2), and delayed stent occlusion (2). Multivariate analyses showed that higher percent stenosis, lower modified Rankin score, and clopidogrel load associated with an activated clotting time above the target range were associated (P ≤ 0.05) with hemorrhagic stroke. Nonsmoking, basilar artery stenosis, diabetes, and older age were associated (P ≤ 0.05) with ischemic events.

CONCLUSIONS

Periprocedural strokes in SAMMPRIS had multiple causes with the most common being perforator occlusion. Although risk factors for periprocedural strokes could be identified, excluding patients with these features from undergoing percutaneous transluminal angioplasty and stenting to lower the procedural risk would limit percutaneous transluminal angioplasty and stenting to a small subset of patients. Moreover, given the small number of events, the present data should be used for hypothesis generation rather than to guide patient selection in clinical practice. Clinical Trial Registration Information- URL: http://clinicaltrials.gov. Unique Identifier: NCT00576693.

Impact of operator and site experience on outcomes after angioplasty and stenting in the SAMMPRIS trial

BACKGROUND AND PURPOSE

To investigate the relationship between physician and site experience and the risk of 30 day hemorrhagic and ischemic strokes in the stenting arm of the Stenting and Aggressive Medical Management for the Prevention of Recurrent Ischemic Stroke (SAMMPRIS) trial.

METHODS

Study records and an investigator survey were examined for physician and site related factors, including: number of Wingspan and aneurysm stents submitted for credentialing, number of study procedures performed in SAMMPRIS, years in practice after training, primary specialty, and site enrollment. Bivariate and multivariate analyses were performed to determine if these factors were associated with the 30 day rate of cerebrovascular events after angioplasty and stenting.

RESULTS

213 patients underwent angioplasty alone (n=5) or angioplasty and stenting (n=208) with study devices by 63 interventionists at 48 sites. For credentialing, the median number of Wingspan and similar aneurysm stent cases submitted by study interventionists were 10 and 6, respectively. Interventionists with higher numbers (>10) of Wingspan cases submitted for credentialing tended to have higher rates of 30 day events (19.0% vs 9.9%) than those with <10 cases. High enrolling sites in the trial tended to have lower rates of hemorrhagic stroke (9.8% at sites enrolling <12 patients vs 2.7% at sites enrolling >12 patients).

CONCLUSIONS

Interventionists credentialed with less Wingspan experience were not responsible for the high rate of periprocedural stroke in SAMMPRIS. Hemorrhagic stroke may be related to low enrollment in the trial but not previous Wingspan experience.

Stenting versus aggressive medical therapy for intracranial arterial stenosis

BACKGROUND

Atherosclerotic intracranial arterial stenosis is an important cause of stroke that is increasingly being treated with percutaneous transluminal angioplasty and stenting (PTAS) to prevent recurrent stroke. However, PTAS has not been compared with medical management in a randomized trial.

METHODS

We randomly assigned patients who had a recent transient ischemic attack or stroke attributed to stenosis of 70 to 99% of the diameter of a major intracranial artery to aggressive medical management alone or aggressive medical management plus PTAS with the use of the Wingspan stent system. The primary end point was stroke or death within 30 days after enrollment or after a revascularization procedure for the qualifying lesion during the follow-up period or stroke in the territory of the qualifying artery beyond 30 days.

RESULTS

Enrollment was stopped after 451 patients underwent randomization, because the 30-day rate of stroke or death was 14.7% in the PTAS group (nonfatal stroke, 12.5%; fatal stroke, 2.2%) and 5.8% in the medical-management group (nonfatal stroke, 5.3%; non-stroke-related death, 0.4%) (P=0.002). Beyond 30 days, stroke in the same territory occurred in 13 patients in each group. Currently, the mean duration of follow-up, which is ongoing, is 11.9 months. The probability of the occurrence of a primary end-point event over time differed significantly between the two treatment groups (P=0.009), with 1-year rates of the primary end point of 20.0% in the PTAS group and 12.2% in the medical-management group.

CONCLUSIONS

In patients with intracranial arterial stenosis, aggressive medical management was superior to PTAS with the use of the Wingspan stent system, both because the risk of early stroke after PTAS was high and because the risk of stroke with aggressive medical therapy alone was lower than expected. (Funded by the National Institute of Neurological Disorders and Stroke and others; SAMMPRIS ClinicalTrials.gov number, NCT00576693.).

Very early hypothermia induction in patients with severe brain injury (the National Acute Brain Injury Study: Hypothermia II): a randomised trial

BACKGROUND

The inconsistent effect of hypothermia treatment on severe brain injury in previous trials might be because hypothermia was induced too late after injury. We aimed to assess whether very early induction of hypothermia improves outcome in patients with severe brain injury.

METHODS

The National Acute Brain Injury Study: Hypothermia II (NABIS: H II) was a randomised, multicentre clinical trial of patients with severe brain injury who were enrolled within 2·5 h of injury at six sites in the USA and Canada. Patients with non-penetrating brain injury who were 16-45 years old and were not responsive to instructions were randomly assigned (1:1) by a random number generator to hypothermia or normothermia. Patients randomly assigned to hypothermia were cooled to 35°C until their trauma assessment was completed. Patients who had none of a second set of exclusion criteria were either cooled to 33°C for 48 h and then gradually rewarmed or treated at normothermia, depending upon their initial treatment assignment. Investigators who assessed the outcome measures were masked to treatment allocation. The primary outcome was the Glasgow outcome scale score at 6 months. Analysis was by modified intention to treat. This trial is registered with ClinicalTrials.gov, NCT00178711.

FINDINGS

Enrolment occurred from December, 2005, to June, 2009, when the trial was terminated for futility. Follow-up was from June, 2006, to December, 2009. 232 patients were initially randomised a mean of 1·6 h (SD 0·5) after injury: 119 to hypothermia and 113 to normothermia. 97 patients (52 in the hypothermia group and 45 in the normothermia group) did not meet any of the second set of exclusion criteria. The mean time to 35°C for the 52 patients in the hypothermia group was 2·6 h (SD 1·2) and to 33°C was 4·4 h (1·5). Outcome was poor (severe disability, vegetative state, or death) in 31 of 52 patients in the hypothermia group and 25 of 56 in the normothermia group (relative risk [RR] 1·08, 95% CI 0·76-1·53; p=0·67). 12 patients in the hypothermia group died compared with eight in the normothermia group (RR 1·30, 95% CI 0·58-2·52; p=0·52).

INTERPRETATION

This trial did not confirm the utility of hypothermia as a primary neuroprotective strategy in patients with severe traumatic brain injury.

Ephrin-A binding and EphA receptor expression delineate the matrix compartment of the striatum

The striatum integrates limbic and neocortical inputs to regulate sensorimotor and psychomotor behaviors. This function is dependent on the segregation of striatal projection neurons into anatomical and functional components, such as the striosome and matrix compartments. In the present study the association of ephrin-A cell surface ligands and EphA receptor tyrosine kinases (RTKs) with the organization of these compartments was determined in postnatal rats. Ephrin-A1 and ephrin-A4 selectively bind to EphA receptors on neurons restricted to the matrix compartment. Binding is absent from the striosomes, which were identified by mu-opioid receptor immunostaining. In contrast, ephrin-A2, ephrin-A3, and ephrin-A5 exhibit a different mosaic binding pattern that appears to define a subset of matrix neurons. In situ hybridization for EphA RTKs reveals that the two different ligand binding patterns strictly match the mRNA expression patterns of EphA4 and EphA7. Ligand-receptor binding assays indicate that ephrin-A1 and ephrin-A4 selectively bind EphA4 but not EphA7 in the lysates of striatal tissue. Conversely, ephrin-A2, ephrin-A3, and ephrin-A5 bind EphA7 but not EphA4. These observations implicate selective interactions between ephrin-A molecules and EphA RTKs as potential mechanisms for regulating the compartmental organization of the striatum.

GM1 produces attenuation of short-term memory deficits in Hebb-Williams maze performance after unilateral entorhinal cortex lesions

The Hebb-Williams maze was used to examine spatial abilities of adult male Sprague-Dawley rats with unilateral electrolytic entorhinal cortex lesions. The injured rats were treated for 14 days with either saline or ganglioside GM1. Testing was begun 7 weeks following injury, and involved 12 maze problems with independent configurations, with immediate starting replacement used for the six trials per problem. Compared to sham-operated counterparts, the rats with lesion plus saline treatment were impaired in total number of errors, initial entry errors, and repeat errors over 12 consecutive problems. GM1-treated rats showed improved performance, making significantly fewer total and repeat errors, indicating that this substance may be potentially useful as therapy after entorhinal cortex injury.

Effects of unilateral entorhinal cortex lesion on retention of water maze performance

In a previous study, adult male Sprague-Dawley rats with unilateral, electrolytic entorhinal cortex lesions showed significant deficits in acquisition of a water maze task that measured working memory. The 10 days of testing used two trials per day with an intertrial interval of 1 h, and the rats with entorhinal damage were impaired in total distance to the platform in both trials. In the present retention study, rats who learned the same task prior to injury and were then retested for 5 days after lesion showed only a first day deficit in total distance to platform in the second trial. Analysis of swim patterns indicated that rats with unilateral entorhinal lesions used an altered strategy in retention testing to find the platform in the second trial of each day and incorporated the use of headings appropriate for Trial 1 only. This altered or compensatory strategy was not the optimum choice for problem solution. Although the rats then were able to switch headings and find the platform without significant impairment in total distance to platform on days 2-5 of testing, the use of an initial incorrect strategy indicated subtle residual deficits in cue integration and use of working memory.

Acute ethanol administration reduces the cognitive deficits associated with traumatic brain injury in rats

The present study was designed to determine whether a low dose of acute ethanol administration could attenuate cognitive deficits associated with traumatic brain injury. Adult male rats received oral administration of ethanol or drinking water 2 h prior to surgery to produce a blood ethanol concentration of 100 mg% and then received bilateral contusion injuries of the medial prefrontal cortex. Seven days after surgery, the rats began 10 days of testing for acquisition of spatial localization in the Morris water maze where they were required to find a hidden platform to escape from the water. The results indicate that the rats given ethanol at the time of injury later spent significantly less time searching for the hidden platform than their water-treated counterparts. On a memory probe test given on the final day of testing, in which the platform was removed from the pool, rats given the ethanol spent more time in the area where the platform had been located indicating that they learned its location better than the lesion/water controls. In addition, acute ethanol treatment reduced some of the histopathology that typically occurs following severe contusion of the medial frontal cortex but did not attenuate post-traumatic formation of edema. These results indicate that acute ethanol intoxication can reduce the severity of cognitive impairments caused by contusive traumatic brain injury and support the contention that there is a dose-response relationship of acute ethanol intoxication in the setting of traumatic brain injury.

Intraseptal injections of 192 IgG saporin produce deficits for strategy selection in spatial-memory tasks

The involvement of the cholinergic septohippocampal system in strategies used to reach a spatial goal was examined by functionally inactivating this system with infusions of 192 IgG saporin, a potent cholinergic immunotoxin. Rats were initially trained on a win-shift radial arm maze (RAM) task and then given injections of either 192 IgG saporin (LES) or saline vehicle (CON) into the medial septum and vertical limb of the diagonal band. Rats were then retested postoperatively on the RAM to assess whether allocentric spatial strategies used to solve the task were impaired. The results indicated that injections of 192 IgG saporin into the septum of rats produced deficits in allocentric strategies used to locate the spatial goal when retested. In addition, place and response learning was also examined in a modified version of the Morris water maze task. In this task, rats with cholinergic lesions were mildly impaired in their ability to learn a place response. In order to clarify further whether rats may have been relying on allocentric or egocentric learning strategies to locate the platform, a probe trial was given on the final test day in which the visible platform was moved to a new location. Control rats swam either to the new platform location or the old platform location indicating the use of both an allocentric and egocentric response. However, rats with the cholinergic septal lesions swam to the new platform location indicating an egocentric response. Taken together, these results suggest that selective cholinergic lesions of the septum produce deficits in spatial strategies used to locate a spatial goal.

Persistent short term memory deficits in Hebb-Williams maze performance are shown by rats with unilateral entorhinal cortex lesions

The spatial abilities of adult, male Sprague-Dawley rats in the Hebb-Williams maze were examined at 6 months after unilateral electrolytic entorhinal cortex lesions. Compared with sham-operated rats, their performance was impaired in both initial entry and repeat entry errors over 12 consecutive problems, using immediate starting replacement for the 6 trials per problem. The configurations of the 12 maze problems are independent, and deficits were seen over the entire course of the testing. This study indicates that Hebb-Williams maze performance deficits after unilateral entorhinal cortex lesion are persistent and can be seen up to 6 months after injury.

Effects of a single intraseptal injection of NGF on spatial learning in the water maze

Male Sprague-Dawley rats given electrolytic lesions of the septum followed by a single intraseptal injection of 5 microg of NGF were trained on a water maze task that assessed their ability to learn the location of a visible platform and the location of platform when it was submerged. Rats with damage to the septum acquired the visible platform version of the task but were significantly impaired in locating the submerged platform. Administration of NGF, however, produced an intermediate ameliorative effect on the measure of latency to find the hidden platform during these trials. In order to determine the relative strength of the place and cue responses learned during the visible and hidden platform training trials, a probe trial was given on the final test day in which the visible platform was moved to a new location. Control rats swam either to the new platform location or the old platform location indicating the use of both a place and cue response. However, both rats with septal damage alone and rats with septal lesions treated with NGF swam directly to the new platform location indicating the relative strength of the cue response. These results support previous findings indicating that a single injection of NGF can produce improvements on a cognitive task, but it may not be doing so by restoring lost spatial functions following septohippocampal damage.

Persistent short term memory deficits in Hebb-Williams maze performance are shown by rats with unilateral entorhinal cortex lesions

The spatial abilities of adult, male Sprague-Dawley rats in the Hebb-Williams maze were examined at 6 months after unilateral electrolytic entorhinal cortex lesions. Compared with sham-operated rats, their performance was impaired in both initial entry and repeat entry errors over 12 consecutive problems, using immediate starting replacement for the 6 trials per problem. The configurations of the 12 maze problems are independent, and deficits were seen over the entire course of the testing. This study indicates that Hebb-Williams maze performance deficits after unilateral entorhinal cortex lesion are persistent and can be seen up to 6 months after injury.

Intraseptal injections of NGF attenuates edema formation following septal lesions in the rat

Rats with electrolytic lesions of the medial septum received a single intraseptal injection of either nerve growth factor (NGF) or saline immediately following surgery. The formation of edema was then assessed at five time points following the lesions to the septum: 6 h, 1 day, 2 days, 3 days, and 5 days. Edema formation was detected as early as 6 h in both groups. However, by 2 days following surgery, the NGF treated rats had significantly less edema formation than their lesion alone counterparts. These results can be taken to indicate that NGF may alter locally mediating events that limit the effects of reactions associated with the inflammation of damaged tissue.

A single intraseptal injection of nerve growth factor facilitates radial maze performance following damage to the medial septum in rats

Rats were trained on a radial maze and then given electrolytic lesions of the MS followed by a single intraseptal injection of 5 micrograms of NGF. Three days later they were re-tested on the maze. They were also post-operatively tested for hyperemotionality. MS lesions severely impaired performance on the radial maze and produced increased emotionality. MS lesions also produced a general decrease in hippocampal high affinity choline transport and acetylcholinesterase staining, which was not affected by NGF administration. NGF treatment ameliorated the behavioral deficit in the radial maze but had no effect on the hyperemotionality. In order to determine whether the NGF was working to restore previously learned spatial abilities, the type of learning strategy used by the animals was also assessed. NGF treatment did not restore previously learned spatial strategies but facilitated recovery of alternative learning strategies. The reduction in cognitive deficit was also paralleled by reduced ventricular enlargement in the NGF treated rats. The present results suggest that a single injection of NGF can produce a long-lasting improvement on a cognitive task and reduce some of the injury-induced, secondary reactive changes that occur following electrolytic MS lesions.

Medial septal lesions in rats produce permanent deficits for strategy selection in a spatial memory task

Rats with medial septal (MS) lesions have been shown to consistently use a stereotypic response strategy rather than a nonstereotypic spatial learning strategy when solving a radial maze task. The present study examined the long-term effects of MS lesions on spatial memory performance to determine whether MS lesions permanently impair rats from using a nonstereotypic strategy. Male rats, initially trained on a radial maze, were given either MS or sham surgeries and were subsequently retested on the maze. Consistent with previous studies, all rats with MS lesions used a stereotypic strategy during the postoperative retest. However, when placed through a series of retraining phases that required the rat to use a nonstereotypic strategy to solve the task, none of the MS rats could solve the task. These results indicate that lesions of the medial septum produce permanent spatial memory deficits that cannot be restored through extensive behavioral training.

Medial septal lesions in rats produce permanent deficits for strategy selection in a spatial memory task

Rats with medial septal (MS) lesions have been shown to consistently use a stereotypic response strategy rather than a nonstereotypic spatial learning strategy when solving a radial maze task. The present study examined the long-term effects of MS lesions on spatial memory performance to determine whether MS lesions permanently impair rats from using a nonstereotypic strategy. Male rats, initially trained on a radial maze, were given either MS or sham surgeries and were subsequently retested on the maze. Consistent with previous studies, all rats with MS lesions used a stereotypic strategy during the postoperative retest. However, when placed through a series of retraining phases that required the rat to use a nonstereotypic strategy to solve the task, none of the MS rats could solve the task. These results indicate that lesions of the medial septum produce permanent spatial memory deficits that cannot be restored through extensive behavioral training.

Lipoprotein-cyclodextrin interaction

Interaction of cyclodextrins with native and isolated lipoproteins was studied by electrophoretic and spectroscopic means. Reaction between these two biomolecules resulted in the formation of soluble and insoluble complexes. Cyclodextrin-mediated precipitation of lipoproteins was strongly affected by the concentration of the oligosaccharide and the presence of guest molecules capable of being entrapped within the cyclodextrin cavity. Lipoprotein precipitation by cyclodextrins was observed under acidic, neutral as well as alkaline conditions. The ionic strength of the medium did not significantly affect this interaction. Under appropriate experimental conditions, most types of cyclodextrins were able to form complexes with the various lipoprotein classes. The ability of cyclodextrins to precipitate lipoproteins was in the order of beta-cyclodextrin greater than alpha-cyclodextrin greater than gamma-cyclodextrin and hydroxyalkylated beta-cyclodextrin. Among the lipoproteins, the order of reactivity with a given cyclodextrin was: low density lipoproteins greater than high density lipoproteins greater than very low density lipoproteins. Competitive studies using L-phenylalanine and methanol, both of which form inclusion complexes with cyclodextrins, reveal that molecular encapsulation plays an important role in the stabilization of beta-cyclodextrin-lipoprotein complexes. The present data also suggests that the binding of cyclodextrins to lipoproteins may involve the formation of exclusion complexes.