LASTE Trial: Thrombectomy for Large Infarct of Unrestricted Size
In patients with anterior circulation LVO and a large established infarct (ASPECTS 5 or lower, with no cap on infarct size; patients older than 80 required ASPECTS 4 or 5) 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 ASPECTS bound for patients aged 80 or younger; patients older than 80 required an ASPECTS of 4 or 5 (the published Methods state 4 or 5 above age 80, while the ClinicalTrials.gov registry entry shown below lists ASPECTS 3 to 5 for patients 80 and older)
- 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 in February 2023 after external positive large-core data emerged from SELECT2 and ANGEL-ASPECT.
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 and no cap on infarct size, LASTE supports offering thrombectomy; patients older than 80 entered LASTE only with an ASPECTS of 4 or 5, so the very-low-ASPECTS evidence does not extend to them. 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