Original ArticleDesign of the Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis Trial
Section snippets
Overall Design
SAMMPRIS is an ongoing, investigator-initiated, randomized clinical trial funded by the National Institute of Neurological Disorders and Stroke (NINDS) that is being conducted at 50 sites in the United States. The primary aim is to determine whether PTAS (using the Gateway PTA balloon catheter and Wingspan Stent System; both manufactured by Boston Scientific Corporation, Natick, MA) combined with aggressive medical management is superior to aggressive medical management alone for preventing the
Statistical Considerations
The expected mean duration of follow-up is 2 years (range 1-3 years). The sample size required to have 80% power to detect a 35% relative risk reduction in the primary endpoint (estimated rate 24.7% at 2 years in the medical arm v 16.1% in the PTAS arm) using a 2-sided log-rank test with probability of a Type I error = 0.05, a 2% lost to follow-up rate, and a 5% crossover from the medical to the PTAS arm is 382 patients per group. The primary endpoint rate for the medical therapy alone group
Data and Safety Monitoring Board
The DSMB meets every 6 months to review the study progress and accumulated data. The main responsibilities of the DSMB are to ensure that study participants are not exposed to unnecessary or unreasonable risks and that the trial is conducted with high scientific and ethical standards. The DSMB is assisted by 2 safety monitors (1 medical, 1 interventional) who review data on individual cases with adverse events. Two interim efficacy analyses are planned for when approximately 33% and 66% of the
Monitoring the Performance of PTAS in the Trial
To ensure patient safety and adherence to the PTAS protocol, the procedure notes from all PTAS procedures are reviewed. PTAS procedure data is first reviewed by the clinical research nurse at the statistical center. If an adverse event is identified, data related to the event (including the interventional procedure note) are promptly referred to the interventional safety monitor for review. Any concerns regarding procedural technique or protocol compliance are relayed to the DSMB and the
Why were patients with remote symptoms and 50% to 69% stenosis excluded from SAMMPRIS?
WASID showed that severity of stenosis was the most powerful predictor for recurrent stroke in the territory of the stenotic artery. The cumulative rates of stroke in the territory in patients with ≥70% stenosis were 18% at 1 year and 19% at 2 years, whereas the rates of stroke in the territory in patients with <70% stenosis were 6% at 1 year and 10% at 2 years.7 Time from qualifying event to enrollment was also a powerful predictor of recurrent stroke, especially in patients with 70% to 99%
Unique Features of SAMMPRIS Design
SAMMPRIS has several unique design features that may be worth incorporating into future secondary prevention trials in stroke. First, we are using aggressive protocol driven management of multiple vascular risk factors as part of the study protocol, with regular performance feedback and suggestions from the coordinating center to improve risk factor management at each site. Second, a lifestyle modification program is used to coach patients about healthy habits. Third, in deciding the
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2020, Journal of Stroke and Cerebrovascular DiseasesCitation Excerpt :We sought to validate these findings in a large multicenter randomized trial cohort of patients with symptomatic severe ICAS from the Stenting and Aggressive Medical Management for Preventing Recurrent stroke in Intracranial Stenosis (SAMMPRIS) trial. The design, patient characteristics, and primary outcome results of SAMMPRIS have been reported previously.4,5 In brief, the SAMMPRIS trial enrolled patients with a stroke or a transient ischemic attack attributed to angiographically determined severe (70%-99%) ICAS in the intracranial internal carotid artery (ICA), middle cerebral artery (MCA), intracranial vertebral artery (VA), or basilar artery (BA).
Poststroke Montreal Cognitive Assessment and Recurrent Stroke in Patients With Symptomatic Intracranial Atherosclerosis
2020, Journal of Stroke and Cerebrovascular DiseasesCitation Excerpt :In our study, the association between cognitive impairment at 3-6-months and recurrent stroke had a trend to be more pronounced in an anterior circulation location. This may be explained by the fact that patients with posterior circulation involvement enrolled in SAMMPRIS generally had unilateral vertebral disease or basilar disease, a phenotype that is less likely to be associated with impaired distal blood flow as compared to those with tandem vertebrobasilar or bilateral vertebral artery lesions28 who were excluded from SAMMPRIS.18 This study has several clinical implications.
Funded by a research grant (U01 NS058728) from the US Public Health Service National Institute of Neurological Disorders and Stroke (NINDS). Other support is provided in the acknowledgment section.
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See appendix for list of study investigators.