LASTE Trial: Thrombectomy for Large Infarct of Unrestricted Size
In patients with anterior circulation LVO and a large established infarct (ASPECTS 5 or lower, no lower limit on infarct volume) treatable within 6.5 hours, does thrombectomy plus medical care shift the mRS distribution toward better outcomes and reduce mortality compared with medical care alone?
Costalat et al. (NEJM 2024) · 333 patients
Population
Included
- Age 18 years or older (no upper age limit)
- Acute ischemic stroke from anterior circulation large vessel occlusion (intracranial ICA or M1)
- Large established infarct on imaging defined as ASPECTS 5 or lower on non-contrast CT, or DWI ASPECTS 5 or lower on MRI, with no lower limit on ASPECTS or infarct volume
- Treatment feasible within 6.5 hours of last-known-well
- Pre-stroke mRS 0 or 1
- Subject is ≥ 18 years old at inclusion (no upper age limit)
- Clinical signs consistent with acute ischemic stroke with symptom onset ≤ 6.5 hours
- Large ischemic core defined as ASPECT Score ≤ 5 on imaging; for patients ≥ 80 years: ASPECT 3-5
- Proved anterior circulation intracranial large vessel occlusion on CTA or MRA
- Informed consent obtained and signed
- Selection imaging performed ≤ 3 hours before randomization
- Anticipated procedure start within 30 minutes of randomization
- Pre-stroke mRS ≤ 1
- Eligible if receiving antiaggregant or anticoagulant agents within 24 hours
- NIHSS > 6
- Thrombolytic therapy initiated per clinical guidelines if indicated
Excluded
- Pre-stroke mRS greater than 1
- Intracranial hemorrhage on baseline imaging
- Posterior circulation occlusion
- Standard contraindications to endovascular thrombectomy
- Comorbid illness expected to limit 90-day follow-up
- Known absence of vascular access
- Known life-threatening allergy to contrast or endovascular products
- Pregnant or lactating females
- Severe comorbidities or life expectancy under 6 months
- Unable to present or participate in follow-up
- Pre-existing neurological or psychiatric disease affecting assessment
- Evidence of vessel recanalization prior to randomization
- Seizures at onset obscuring stroke diagnosis
- Current participation in another investigational drug study
- Suspicion of aortic dissection
- Major patients under guardianship
- Blood glucose < 50 or > 400 mg/dL
- Creatinine > 4.0 mg/dL (unless on dialysis)
- Platelet count < 50,000/µL
- INR > 3.0 or PTT > 3 times upper limit of normal
Imaging exclusion
- Isolated proximal cervical ICA occlusions or isolated M2 occlusions
- Intracranial hemorrhage evidence on imaging
- Excessive cervical vessel tortuosity
- High suspicion of intracranial stenosis
- Suspected cerebral vascular disease
- Presumed calcified embolus or stenosis decompensation
- Intracranial stent in same vascular territory
- Occlusions in multiple vascular territories
- Significant mass effect with midline shift
- Ipsilateral cervical ICA lesion requiring stent placement
Source: ClinicalTrials.gov NCT03811769· Retrieved 2026-06-08
Primary Outcome — mRS Ordinal Shift at 90 Days
All randomized patients (anterior circulation LVO, ASPECTS 5 or lower)
mRS Ordinal Shift at 90 Days
cOR 1.63
95% CI 1.29 to 2.06 · P <0.001
Median mRS — Thrombectomy
4
Median mRS — Medical Care
6
Mortality: 36.1% (thrombectomy) vs 55.5% (medical care) · sICH: 9.6% vs 5.7%
Study Arms
- Agent
- Mechanical thrombectomy using any thrombectomy device approved by local regulatory authorities
- Route
- Endovascular
- Frequency
- Single procedure; device choice at operator discretion
- Duration
- Procedure start within 30 min of randomization; randomization ≤ 6.5 h from onset/LKW
- Co-interventions
- Medical care per current European guidelines for acute ischemic stroke, including IV thrombolysis (alteplase) when indicated. IV thrombolysis given in ~34.6% of thrombectomy-group patients (Table 1, p.1681).
Performed at certified high-volume stroke centers in France and Spain. Successful revascularization = mTICI 2b–3. Thrombectomy performed in 151/159 ITT; 8 had spontaneous clot lysis (Costalat NEJM 2024 p.1679-1680).
- Agent
- Best medical care per current European acute ischemic stroke guidelines
- Route
- Medical
- Duration
- Acute hospitalization
- Co-interventions
- IV thrombolysis (alteplase) when indicated. IV thrombolysis given in ~35.2% of control-group patients (Table 1, p.1681).
No endovascular thrombectomy. Admitted to acute-stroke units or neuro ICUs; treated per European guidelines (p.1679).
Trial Design
Type
- Randomized large-core trial
- Thrombectomy plus medical care vs medical care alone
- Anterior circulation proximal occlusion with ASPECTS <=5
- Imaging by CT or MRI within 6.5 hours
Timeline
Stopped early after external positive large-core data
N
333
Enrollment
French multicenter RCT enrolling 333 patients across multiple centers (Costalat NEJM 2024). Stopped early after external positive large-core data emerged from ANGEL-ASPECT, SELECT2, and TESLA.
ClinicalTrials.gov
NCT03811769Bedside Pearl
A very low ASPECTS is no longer an automatic disqualifier. For an anterior circulation LVO patient inside 6.5 hours with ASPECTS 5 or lower, even with no measured floor on infarct volume, LASTE supports offering thrombectomy. Frame the conversation around mortality reduction (55.5% to 36.1%) and median mRS shift from 6 to 4, not around full functional recovery.
See also