Mechanical thrombectomy for treating large artery occlusion in stroke patients beyond 24 hours

An Investigator Initiated and Conducted, Prospective, Multicenter, Randomized Outcome-blinded Study of Treating Mechanical Thrombectomy Exceeding 24 Hours in Patients With Acute Ischemic Stroke Due to Large Vessel Occlusion

Not applicable Interventional The George Institute for Global Health, China · NCT05326932

This study is testing if a procedure called mechanical thrombectomy can help stroke patients with blocked arteries who are treated 24 to 72 hours after their symptoms started, compared to just standard medical care.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment382 (estimated)
Ages18 Years and up
SexAll
SponsorThe George Institute for Global Health, China Academic / other
Locations1 site (Shanghai)
Trial IDNCT05326932 on ClinicalTrials.gov

What this trial studies

This clinical trial investigates the effectiveness of mechanical thrombectomy (MT) in patients with acute ischemic stroke (AIS) caused by large vessel occlusion (LVO) when performed 24 to 72 hours after the last known well time. It is a multi-center, randomized, open-label trial that compares the outcomes of MT against standard medical care without MT. The study aims to assess not only the functional outcomes but also the safety of the procedure, including risks of intracranial hemorrhage and other serious adverse events. Secondary objectives include evaluating neurological recovery, infarct size, and quality of life metrics.

Who should consider this trial

Good fit: Ideal candidates are adults aged 18 and older who have experienced an acute ischemic stroke due to anterior circulation large vessel occlusion within 24 to 72 hours.

Not a fit: Patients with advanced dementia, major pre-stroke disability, or those unlikely to benefit from the trial due to severe comorbidities may not receive any benefit.

Why it matters

Potential benefit: If successful, this trial could provide a new treatment option for stroke patients who present beyond the traditional treatment window, potentially improving their functional outcomes.

How similar studies have performed: While the approach of treating stroke patients beyond the standard time window is novel, similar studies have shown promising results in extending treatment eligibility.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

1. Age ≥18 years
2. Present 24-72 hours of stroke onset or last seen well
3. Clinical diagnosis of AIS due to anterior circulation LVO (from internal carotid artery (ICA) extracranial segment to middle cerebral artery (MCA) M1 and M2 segment) on brain imaging
4. National Institute of Health stroke scale (NIHSS) ≥6 at randomisation
5. Viable cerebral tissue on computerized tomography perfusion (CTP) or magnetic resonance imaging perfusion (MRP) assessed: infarct core volume \<50mL, mismatch ratio ≥1.8 and mismatch volume ≥15mL
6. Written informed consent (by patient or proxy, according to local requirements)

Exclusion Criteria:

Clinical Exclusion Criteria

1. Considered unlikely to benefit from trial (e.g. advanced dementia, major pre-stroke disability (prior modified Rankins scale (mRS) ≥2), high likelihood of early death), as judged by the responsible treating clinician
2. Major co-morbid disease that could interfere with outcome assessments and follow-up (e.g. cancer, severe heart failure, kidney failure)
3. Pregnancy
4. Unable to undergo a CTP or MRP
5. Known allergy to iodine, heparin, anaesthesia, or other definite contraindication to receiving endovascular treatment (EVT) procedure
6. Seizures at stroke onset or before randomization and baseline NIHSS scores cannot be accurately determined
7. Baseline blood glucose of \<50mg/dL (2.78 mmol/L) or \>400mg/dL (22.20 mmol/L)
8. Baseline platelet count \<50,000/uL
9. Known hereditary or acquired hemorrhagic diathesis, coagulation factor deficiency; recent oral anticoagulant therapy with International normalized ratio (INR) \>3
10. Severe, sustained hypertension (systolic blood pressure (BP) \>220 mmHg or diastolic BP \>120 mmHg)
11. Presumed septic embolus, suspicion of bacterial endocarditis
12. EVT attempted after stroke onset
13. Unlikely to participate in follow-up assessments
14. Currently participating in another trial that may affect outcomes.
15. Any other condition that, in the opinion of the investigator will pose a significant hazard to the subject if participating in the trial.

Neuroimaging Exclusion Criteria

1. Intracranial hemorrhage (ICH), including parenchymal hemorrhage, ventricular hemorrhage, subarachnoid hemorrhage, and subdural/exsanguination
2. Evidence of intracranial tumor (except small meningioma)
3. Significant mass effect with midline shift
4. Aortic dissection
5. Intracranial stent implanted in the same vascular territory
6. Any other condition that may affect EVT procedure, like the tortuous vascular path the device is difficult to reach the target position or difficult to recover
7. Occlusions in multiple vascular territories confirmed on Computerized tomography angiography (CTA)/ Magnetic resonance imaging angiography (MRA) (e.g. bilateral MCA occlusions, or an MCA and a basilar artery occlusion)

Where this trial is running

Shanghai

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Acute Ischemic StrokeAcute ischemic strokeLarge vessel occlusionMechanical thrombectomyExtended timeRandomised clinical trial
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.