Microclots and neutrophil activation as markers of stroke risk and reperfusion failure

Micro-clots and Neutrophil Activation as Potential Indicators for Stroke Risk and Reperfusion Failure The CLOTSAFE - Study (Micro-CLOTs, Stroke Risk, Activated Neutrophils, Reperfusion FailurE)

University of Zurich · NCT06530927

This project tries to see if tiny blood clots and activated neutrophils in blood can predict stroke risk and explain why some people with ischemic stroke don't improve after clot removal.

Quick facts

Study typeObservational
Enrollment500 (estimated)
Ages18 Years and up
SexAll
SponsorUniversity of Zurich (other)
Locations1 site (Zurich, Canton of Zurich)
Trial IDNCT06530927 on ClinicalTrials.gov

What this trial studies

This prospective observational study will collect peripheral blood and clot material from up to 500 patients with acute and chronic ischemic stroke and from individuals at high risk of stroke. Researchers will use digital holotomography, atomic force microscopy, and micro-CT to characterize the size, shape, and surface properties of microclots and activated neutrophils. They will compare these structural and chemical features with clinical outcomes, stroke cause, and occurrence of reperfusion failure after mechanical thrombectomy. The goal is to identify blood-based markers that relate to capillary obstruction and poor recovery after otherwise successful recanalization.

Who should consider this trial

Good fit: Ideal candidates are adults able to give consent who have confirmed ischemic stroke (within 12 hours of symptom onset for acute groups) or individuals at high risk of stroke, and who can attend the Zurich study site for blood sampling and imaging.

Not a fit: People under 18, pregnant individuals, those with hemorrhagic stroke, or patients unable to attend the Zurich site for required sampling and imaging are unlikely to benefit from participation.

Why it matters

Potential benefit: If successful, this work could help identify patients at higher risk of poor outcome after reperfusion and point to targets or strategies to improve microvascular flow and recovery.

How similar studies have performed: Preclinical rodent studies have shown that removing capillary stalls associated with neutrophils improves reperfusion and recovery, but human data are limited and this application in patients is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

Patients without acute stroke CS or CSG

* No previous stroke or previous stroke ≥ 1 year ago
* Signed informed consent

Patients with acute stroke (AS-noTx, AS-IVT, AS-MT):

* Patients admitted with high suspicion of acute ischemic stroke
* Time of onset of stroke symptoms ≤ 12 hours
* Consent according to the regulations of research in an emergency situation
* Ischemic stroke later confirmed

Exclusion Criteria:

All groups:

* Pregnancy
* Age under 18 years

Acute Stroke no Therapy

• Acute treatment with IVT or with MT

Acute Stroke IVT-Group • Acute treatment with MT or without IVT

Acute Stroke MT-Group

• Acute treatment without MT

Where this trial is running

Zurich, Canton of Zurich

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.

View on ClinicalTrials.gov →

Conditions: Ischemic Stroke, microclots, activated neutrophils, reperfusion failure, 3D rotational digital tomography

Last reviewed 2026-05-15 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.