PDF: SAMMPRIS
(2011)Objective
Aggressive medical management alone versus aggressive medical management plus stenting in patients with symptomatic intracranial arterial stenosis.
Study Summary
Intervention
Aggressive risk factor control (aspirin 325 mg + clopidogrel 75 mg daily for 90 days, plus statin and antihypertensive therapy) vs. same regimen plus intracranial stenting using the Wingspan system.
Inclusion Criteria
Patients with TIA or non-disabling stroke within 30 days attributed to 70–99% intracranial stenosis, confirmed by angiography.
Study Design
Arms: Medical Management vs. PTAS (Stenting)
Patients per Arm: Medical: 227, PTAS: 224
Outcome
Bottom Line
In patients with symptomatic severe intracranial arterial stenosis, aggressive medical management alone was superior to PTAS with the Wingspan stent system. The trial was stopped early because of a significantly higher rate of periprocedural stroke or death in the PTAS group (14.7% vs 5.8% at 30 days) and a lower-than-expected stroke rate with aggressive medical therapy alone.
Major Points
- SAMMPRIS was a randomized trial comparing PTAS (Gateway balloon + Wingspan stent) plus aggressive medical management to aggressive medical management alone in 451 patients with recent symptomatic 70–99% intracranial stenosis.
- Eligible vessels: intracranial ICA, MCA (M1 segment), vertebral artery (V4 segment), and basilar artery. MCA was the most common qualifying vessel (~44%).
- Enrollment was stopped prematurely after 451 of planned 764 patients due to safety concerns in the PTAS group.
- The 30-day rate of stroke or death was significantly higher in the PTAS group (14.7% vs. 5.8%, P=0.002). Most excess events were periprocedural ischemic strokes (9 patients) and hemorrhagic strokes (5 patients).
- Over a mean follow-up of 11.9 months, the primary endpoint (stroke or death within 30 days, or territory stroke beyond 30 days) was 20.0% in the PTAS group vs 12.2% in the medical group (P=0.009).
- The stroke rate with aggressive medical management (5.8% at 30 days, 12.2% at 1 year) was substantially lower than historical controls (~10.7% at 1 year in WASID), highlighting the efficacy of intensive risk factor management with dual antiplatelet therapy, SBP <140 mmHg, and LDL <70 mg/dL.
- Long-term follow-up (median 32.4 months, published 2014) confirmed sustained superiority of medical management: 3-year rates of primary endpoint 14.9% (medical) vs 23.9% (PTAS).
Study Design
- Study Type
- Investigator-initiated, randomized clinical trial.
- Randomization
- Yes
- Blinding
- Unblinded (open-label), but endpoints were adjudicated by independent panels unaware of treatment assignments.
- Sample Size
- 451
- Follow-up
- Mean of 11.9 months at the time of publication; follow-up was ongoing.
- Centers
- 50
- Countries
- United States
Primary Outcome
Definition: A composite of stroke or death within 30 days of enrollment, or stroke in the territory of the qualifying artery after 30 days.
| Control | Intervention | HR/OR | P-value |
|---|---|---|---|
| 12.2% (at 1 year) | 20.0% (at 1 year) | - | 0.009 (log-rank test for the entire follow-up period) |
Limitations & Criticisms
- Results may not apply to patients with moderate stenosis (50–69%) or those >30 days from qualifying event — these were excluded.
- Only evaluated the Wingspan stent system — results may differ with newer stent technology (e.g., balloon-mounted stents, drug-eluting stents).
- Angioplasty alone was not tested as a separate arm.
- High operator variability — despite credentialing requirements, periprocedural complication rates varied across sites.
- The aggressive medical regimen (monthly visits, lifestyle coaching, strict targets) may be difficult to replicate in routine clinical practice.
- Does not address patients with progressive symptoms despite maximal medical therapy — a population that may benefit from intervention.
- Stopped early, limiting power for subgroup analyses by vessel territory or stenosis severity.
- Long-term follow-up (2014) showed the medical group's stroke rate rose modestly over time, but medical management remained superior.
Citation
N Engl J Med 2011;365:993-1003.