REVASCAT
Thrombectomy within 8 Hours after Symptom Onset in Ischemic Stroke
Clinical Question
In patients with acute ischemic stroke due to a proximal anterior circulation occlusion who can be treated within 8 hours of symptom onset, does endovascular therapy with the Solitaire stent retriever improve functional outcomes compared to medical therapy alone?
Bottom Line
Among patients with anterior circulation large-vessel occlusion stroke treatable within 8 hours, endovascular thrombectomy with the Solitaire stent retriever significantly reduced the severity of post-stroke disability and increased the rate of functional independence at 90 days compared with medical therapy alone.
Major Points
- One of five landmark thrombectomy RCTs published in 2015 (MR CLEAN, ESCAPE, EXTEND-IA, SWIFT PRIME, REVASCAT) that collectively established mechanical thrombectomy as standard of care for LVO stroke.
- Conducted at 4 comprehensive stroke centers in Catalonia, Spain — the most geographically concentrated of the 2015 trials.
- Stopped early at 206 patients (target 690) due to loss of equipoise after MR CLEAN, ESCAPE, and EXTEND-IA published positive results.
- Unique 8-hour treatment window — the longest among the 2015 trials (MR CLEAN 6h, ESCAPE 12h, EXTEND-IA 6h, SWIFT PRIME 6h) — providing early evidence for extended time windows.
- Primary outcome: ordinal shift in mRS at 90 days favored thrombectomy (adjusted OR 1.7, 95% CI 1.05–2.8). Functional independence (mRS 0–2): 43.7% vs 28.2%.
- Dramatic early neurologic improvement at 24h (NIHSS drop ≥8 or score 0–2): 59% vs 20% (adjusted OR 5.8, 95% CI 3.0–11.1) — the most striking 24-hour outcome among the 2015 trials.
- Occlusion sites: ICA ~35%, M1 ~65%. Solitaire stent retriever was the exclusive first-line device.
- High IV tPA co-treatment rate: 68–78% received alteplase before randomization.
- No significant difference in sICH (1.9% each group) or 90-day mortality (18.4% vs 15.5%).
- Notably included older patients (age cap initially 80, later amended to 85) and required ASPECTS >6 on CT or >5 on DWI — stricter imaging criteria than MR CLEAN.
Design
Study Type: Multicenter, prospective, randomized, open-label phase 3 study with blinded evaluation of outcomes.
Randomization: 1
Blinding: Open-label for treatment assignment; outcome assessors for the modified Rankin Scale were blinded.
Enrollment Period: November 2012 through December 2014.
Follow-up Duration: 90 days.
Centers: 4
Countries: Spain
Sample Size: 206
Analysis: Intention-to-treat.
Inclusion Criteria
- Age 18 to 80 years (later amended to 85 years).
- Occlusion in the proximal anterior circulation (intracranial internal carotid artery or M1 segment of the middle cerebral artery).
- Could be treated within 8 hours after symptom onset.
- Pre-stroke modified Rankin Scale score of 1 or less.
- Baseline NIHSS score of 6 or more.
- Absence of a large ischemic core on imaging (ASPECTS >6 on CT or >5 on DWI).
Exclusion Criteria
- Large infarct core on imaging (ASPECTS ≤6 on CT or ≤5 on DWI-MRI).
- Prestroke modified Rankin Scale score >1 (pre-existing significant disability).
- NIHSS <6 (mild stroke).
- No confirmed proximal anterior circulation occlusion on CTA/MRA.
- Rapidly improving neurological symptoms.
- Known hemorrhagic diathesis or coagulopathy.
- Baseline blood glucose <50 mg/dL.
- Severe contrast allergy or renal insufficiency.
- Life expectancy <6 months from pre-existing condition.
- Pregnancy.
- Participation in another clinical trial.
Baseline Characteristics
| Characteristic | Control | Active |
|---|---|---|
| Mean age ±SD - yr | 67.2±9.5 | 65.7±11.3 |
| Male sex - no. (%) | 54 (52.4) | 55 (53.4) |
| Atrial fibrillation - no. (%) | 37 (35.9) | 35 (34.0) |
| Hypertension - no. (%) | 72 (69.9) | 62 (60.2) |
| Diabetes mellitus - no. (%) | 21 (20.4) | 18 (17.5) |
| Dyslipidemia - no. (%) | 41 (39.8) | 39 (37.9) |
| Current smoker - no. (%) | 26 (25.2) | 29 (28.2) |
| Prior stroke - no. (%) | 10 (9.7) | 9 (8.7) |
| Median NIHSS score (IQR) | 17.0 (12.0-19.0) | 17.0 (14.0-20.0) |
| Treatment with intravenous alteplase - no. (%) | 80 (77.7) | 70 (68.0) |
| Median ASPECTS value (IQR) | 8.0 (6.0-9.0) | 7.0 (6.0-9.0) |
| Occlusion site - ICA - no./total no. (%) | 36/101 (35.6) | 36/102 (35.3) |
| Occlusion site - M1 - no./total no. (%) | 65/101 (64.4) | 66/102 (64.7) |
| Median time from onset to randomization (IQR) - min | 269 (192–349) | 282 (196–362) |
Arms
| Field | Control | Thrombectomy + Medical Therapy |
|---|---|---|
| Intervention | Standard medical therapy including IV alteplase (0.9 mg/kg, max 90 mg) if eligible within 4.5h of onset. Antiplatelet agents, antihypertensives, statins, and DVT prophylaxis per local protocols. IV alteplase was given to 77.7% of control patients. No endovascular intervention permitted. | Endovascular thrombectomy using Solitaire FR or Solitaire 2 stent retriever as the mandated first-line device. Up to 6 passes allowed. Conscious sedation or general anesthesia at operator discretion. Rescue therapy with other devices permitted if Solitaire failed. Intra-arterial tPA not permitted. Balloon guide catheters used in most cases. Target: groin puncture within 30 minutes of randomization. All patients also received standard medical therapy including IV alteplase if eligible (68% received it). |
| Duration | 90 days | 90 days |
Outcomes
| Outcome | Type | Control | Intervention | HR / OR / RR | P-value |
|---|---|---|---|---|---|
| The severity of global disability at 90 days, assessed by the distribution of scores on the modified Rankin scale (analyzed as an ordinal shift). | Primary | 1.7 | |||
| Functional independence (mRS 0-2) at 90 days | Secondary | 28.2% (29/103) | 43.7% (45/103) | Adjusted OR 2.1 (95% CI, 1.1 to 4.0) | |
| Dramatic neurologic improvement at 24 hr (NIHSS decrease ≥8 or score 0-2) | Secondary | 20.0% (20/100) | 59.0% (59/100) | Adjusted OR 5.8 (95% CI, 3.0 to 11.1) | |
| Death at 90 days | Adverse | 15.5% (16/103) | 18.4% (19/103) | Risk Ratio 1.2 (95% CI, 0.6 to 2.2) | 0.60 |
| Symptomatic intracranial hemorrhage (SITS-MOST criteria) at 90 days | Adverse | 1.9% (2/103) | 1.9% (2/103) | 1.00 |
Subgroup Analysis
Benefit was consistent across prespecified subgroups (age <70 vs ≥70, NIHSS <17 vs ≥17, ICA vs M1 occlusion, ASPECTS ≤7 vs >7, time to randomization <4.5h vs ≥4.5h). Notably, treatment effect persisted in the 4.5–8 hour subgroup (aOR 1.3), providing early evidence for extended window thrombectomy. Patients receiving IV tPA benefited similarly to those not receiving it. The 8-hour window subgroup data helped inform DAWN and DEFUSE 3 trial designs. Trial was underpowered for formal interaction testing.
Criticisms
- Stopped early at 206/690 patients (30%) — markedly underpowered for subgroup analyses and rare event detection.
- Conducted at only 4 highly experienced centers in Catalonia, Spain — among the most geographically restricted of the 2015 thrombectomy trials, limiting generalizability.
- Protocol mandated vessel occlusion confirmation 30 minutes after alteplase administration, potentially delaying thrombectomy in bridging therapy patients.
- Discrepancies between site and core lab ASPECTS readings — some patients had ASPECTS ≤6 on core lab review but were enrolled based on site interpretation.
- Used ASPECTS on NCCT/DWI rather than advanced perfusion imaging (unlike EXTEND-IA and SWIFT PRIME), potentially including patients with larger established infarcts.
- Open-label treatment assignment with potential for bias in post-stroke care intensity, partially mitigated by blinded outcome assessment.
- Solitaire was mandated as first-line device — results may not generalize to other stent retriever or aspiration-first approaches.
- Higher mortality in thrombectomy group (18.4% vs 15.5%), though not significant — raises questions about safety in this extended-window population.
Funding
Fundació Ictus Malaltia Vascular through an unrestricted grant from Covidien and others.
Based on: REVASCAT (The New England Journal of Medicine, 2015)
Authors: T.G. Jovin, A. Chamorro, E. Cobo, ..., and A. Dávalos
Citation: N Engl J Med 2015;372:2296-306.
Content summarized and formatted by NeuroTrials.ai.