PRISMS - Alteplase Minor Stroke
(2018)Objective
To evaluate whether intravenous alteplase improves functional outcomes at 90 days compared to aspirin in patients with acute ischemic stroke, NIHSS score 0–5, and deficits judged not clearly disabling.
Study Summary
• Higher rate of symptomatic intracranial hemorrhage with alteplase compared to aspirin
Intervention
Randomized to receive either intravenous alteplase 0.9 mg/kg plus oral placebo or intravenous placebo plus oral aspirin 325 mg, followed for 90 days.
Inclusion Criteria
Adults ≥18 years with acute ischemic stroke, NIHSS score 0–5, deficits not clearly disabling, treatment feasible within 3 hours; excluded if alteplase contraindications present.
Study Design
Arms: 1) IV alteplase + oral placebo, 2) IV placebo + oral aspirin 325 mg
Patients per Arm: 156 alteplase, 157 aspirin
Outcome
• Symptomatic intracranial hemorrhage: 3.2% alteplase vs 0% aspirin
• Mortality: 0.6% alteplase vs 0% aspirin
Bottom Line
Among patients with minor, nondisabling acute ischemic stroke, alteplase did not increase the likelihood of favorable 90-day functional outcome compared with aspirin, and symptomatic intracranial hemorrhage occurred only in the alteplase group.
Major Points
- Phase 3b, double-blind, double-placebo, multicenter randomized trial; enrollment from May 30, 2014 to December 20, 2016 with final follow-up March 22, 2017.
- 313 patients randomized within 3 hours of onset: 156 to alteplase and 157 to aspirin; median NIHSS 2.
- Primary outcome (mRS 0–1 at 90 days): 78.2% alteplase vs 81.5% aspirin; adjusted risk difference −1.1% (95% CI −9.4% to 7.3%).
- Symptomatic intracranial hemorrhage within 36 hours: 3.2% (5/156) with alteplase vs 0% with aspirin.
- Trial terminated early for slow enrollment; results underpowered for definitive conclusions.
Study Design
- Study Type
- Phase 3b, double-blind, double-placebo, multicenter randomized clinical trial
- Randomization
- Yes
- Blinding
- Participants and investigators blinded; intravenous and oral placebos matched to maintain blinding
- Sample Size
- 313
- Follow-up
- 90 days
- Centers
- 53
- Countries
- United States
Primary Outcome
Definition: Favorable functional outcome defined as modified Rankin Scale (mRS) score 0–1 at 90 days
| Control | Intervention | HR/OR | P-value |
|---|---|---|---|
| 81.5% | 78.2% | - (Adjusted risk difference −1.1% (95% CI −9.4% to 7.3%)) |
Limitations & Criticisms
- Early termination due to slow enrollment led to underpowering and uncertainty around estimates.
- Potential selection bias toward enrolling patients with very mild deficits despite standardized tools.
- Subjective determination of 'not clearly disabling' deficits across sites.
- Relatively high loss to follow-up at 90 days with reliance on imputation.
- Findings not generalizable to patients with clearly disabling deficits or to populations outside trial criteria.
Citation
JAMA. 2018;320(2):156-166. doi:10.1001/jama.2018.8496