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Microclots and Neutrophil Activation as Potential Indicators for Stroke Risk and Reperfusion Failure (CLOTSAFE)

University of Zurich (UZH) logo

University of Zurich (UZH)

Status

Enrolling

Conditions

Ischemic Stroke

Treatments

Diagnostic Test: Atomic Force Microscopy
Diagnostic Test: 3D rotational digital tomography
Diagnostic Test: Micro-Computertomography

Study type

Observational

Funder types

Other

Identifiers

NCT06530927
2024-01353

Details and patient eligibility

About

Stroke remains a major health burden worldwide. Many patients are severely disabled and stay in need of care. Mechanical thrombectomy has dramatically improved outcomes for stroke patients with large vessel occlusions, yet 40-50% of patients with successful recanalization remain severely disabled despite successful recanalization, a scenario called "futile recanalization". One of the causes for this lack of treatment effect is capillary obstruction, or "no reflow", potentially resulting from activated neutrophils and micrometer-sized blood clots. To address this issue, we employ digital holotomographic and atomic force microscopy to investigate the structural and chemical characteristics of blood and clot material in stroke patients and individuals at high risk of developing a stroke. Our study elucidates the association of activated neutrophils and microclots with stroke risk, and may be associated with clinical outcome, stroke ethology and reperfusion failure in patients with stroke. Leveraging label-free microscopy tools, could potentially lead to the discovery of new biomarkers for individualized stroke treatment and prevention, ultimately offering rapid identification of at risk patients and improving clinical outcomes

Full description

Background:

Stroke remains a major health burden worldwide. Many patients are severely disabled and stay in need of care. Since introducing mechanical thrombectomy as a therapeutic option, clinical outcome has drastically improved over the last few years. However, despite successful macrovascular reperfusion (recanalization), patients with stroke still have a significant risk (about 40-50%) of remaining severely disabled, a scenario called "futile recanalization". One of the causes for this lack of treatment effect is capillary obstruction, or "no reflow", potentially resulting from activated neutrophils and micrometer-sized blood clots. Previous work in rodent stroke models demonstrated that removal of these capillary stalls indeed improves reperfusion and recovery after stroke. However, there is a lack of knowledge regarding the role of neutrophils or microclots in patients with stroke, and their potential to indicate reperfusion failure.

Aim:

The goal of our study is to search for activated neutrophils and microclots in peripheral blood samples from patients with stroke. We anticipate that neutrophil and microclot characteristics such as size, shape, or surface structure may indicate stroke risk, and may be associated with clinical outcome, stroke ethology and reperfusion failure in patients with stroke. Our goal is to improve the prediction of stroke risk and treatment success.

Methodology:

We plan to prospectively include 500 patients with acute and chronic stroke, as well as a control group. We have teamed up with biophysicists from the Swiss Federal Laboratories for Materials Science (EMPA) using the novel microscopic tools 3D rotational digital tomography (DHTM) to achieve an unprecedented resolution of less than 10 μm for detection of altered neutrophil phenotypes and microclots in peripheral blood samples. Furthermore, in patients undergoing mechanical thrombectomy, retrieved clots will be analyzed with high-density micro-computertomography (micro-CT). Quantity, mechanical and structural properties of microclots and neutrophils will be correlated with risk of reperfusion failure, stroke recurrence and clinical recovery. Analyses of clots from patients with large vessel occlusion will be used to derive risk of reperfusion failure along with most likely source of the clot, and thus, most likely stroke etiology.

Potential Significance:

Current diagnostic tools are insufficient to predict response to treatment, clot source or stroke recurrence risk. Our project has the potential to discover new, clinically applicable biomarkers identifying patients at risk within a few hours, enabling individualized stroke treatment and prevention.

Enrollment

500 estimated patients

Sex

All

Ages

18+ years old

Volunteers

Accepts Healthy Volunteers

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

Trial design

500 participants in 5 patient groups

Control Group
Description:
Patients without previous documented stroke
Treatment:
Diagnostic Test: 3D rotational digital tomography
Diagnostic Test: Atomic Force Microscopy
Chronic Stroke Group
Description:
Patients with previous stroke ≥1year ago
Treatment:
Diagnostic Test: 3D rotational digital tomography
Diagnostic Test: Atomic Force Microscopy
Acute Stroke No Therapy Group
Description:
Patients with acute stroke, but without intravenous thrombolysis or mechanical thrombectomy
Treatment:
Diagnostic Test: 3D rotational digital tomography
Diagnostic Test: Atomic Force Microscopy
Acute Stroke IVT only Group
Description:
Patients with acute stroke and intravenous thrombolysis
Treatment:
Diagnostic Test: 3D rotational digital tomography
Diagnostic Test: Atomic Force Microscopy
Acute Stroke MT-Group
Description:
Patients with acute stroke and mechanical thrombectomy
Treatment:
Diagnostic Test: Micro-Computertomography
Diagnostic Test: 3D rotational digital tomography
Diagnostic Test: Atomic Force Microscopy

Trial contacts and locations

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Central trial contact

Lukas Otto, Dr. med.; Susanne Wegener, Prof.

Data sourced from clinicaltrials.gov

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