RETRIEVE-AMI Study (RETRIEVE-AMI)

September 3, 2025 updated by: Giovanni Luigi De Maria, Oxford University Hospitals NHS Trust

Stent Retriever Thrombectomy for Thrombus Burden Reduction in Patients With Acute Myocardial Infarction - RETRIEVE-AMI Study

Heart attacks are caused by the sudden formation of a clot inside a diseased coronary artery which reduces blood flow beyond the blockage site. During conventional treatment of the blockage with what is known as a stent; a stainless steel tub that keeps the artery open, the clot that has formed is disrupted and is pushed further down leading to damage in smaller blood vessels supplying the heart muscle. This additional damage can lead to long-term heart muscle damage influencing recovery and wellbeing. The original concept that was tested to prevent this 'clot shower' was that of a suction device to withdraw the clot before stenting. However, this approach has not translated to patient benefit. Amongst the reasons put forward for the inefficacy of the suction device was that it does not remove the entire clot as it does not interact with it. A new device that physically interacts with the clot and traps it before pulling it out - the stent retriever - is now routinely used in stroke therapy to remove clots in the arteries supplying the brain. This device has been successfully used as a last resort to remove clots in a small number of heart attacks. The investigators hypothesize that stent retriever therapy will be more effective in clot removal than the current standard of care; suction or stenting. To study this, the investigators propose the RETRIEVE-AMI randomised controlled trial.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

81

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Primary PCI patient with ST elevation myocardial infarction (STEMI)
  • TIMI 0/1 flow at presentation
  • Angiographic thrombus score ≥ 4
  • Vessel diameter at site of occlusion ≥ 3.0 mm (measured by quantitative coronary angiography)

Exclusion Criteria:

  • Female participant who is pregnant or lactating
  • Participant with known hypersensitivity to nickel-titanium
  • Unconscious at presentation
  • Late presenter (pain to wire time > 12 h)
  • Class Killip III/IV and/or profound bradycardia (Heart rate < 40 bpm)
  • Known history of kidney failure
  • Ostial occlusion
  • Highly tortuous vessel
  • Highly calcified vessel
  • Suspected (angiographically) spontaneous coronary artery dissection
  • Stent thrombosis
  • Previous stent implanted proximal to the occlusion site
  • Previous coronary artery bypass graft surgery (CABG)
  • Previous STEMI/Transient Ischemic Attack/Stroke
  • Known anaemia (Hemoglobin <9)

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Standalone Percutaneous Coronary Intervention
Participants will have standard of care treatment. They will undergo PCI with devices and techniques driven by clinical decision making at the patient level and institutional level, and carried out in accordance with the Oxford University Hospitals NHS Foundation Trust department guidelines.
Procedure: Percutaneous Coronary Intervention
Standard of care
Active Comparator: Percutaneous Coronary Intervention and Thrombus Aspiration
Participants will have standard of care treatment with manual thrombectomy catheter and PCI. They will undergo PCI with devices and techniques driven by clinical decision making at the patient level and institutional level, and carried out in accordance with the Oxford University Hospitals NHS Foundation Trust department guidelines.
Procedure: Percutaneous Coronary Intervention
Standard of care
Procedure: Thrombus Aspiration
Standard of care treatment with manual thrombectomy catheter
Other Names:
  • Aspiration-assisted thrombectomy
Experimental: Percutaneous Coronary Intervention and Retriever Thrombectomy
Participants randomised to the stent-retriever thrombectomy arm of the RETRIEVE AMI trial will undergo stent-retriever thrombectomy with the SolitaireTM X Revascularisation Device.
Procedure: Percutaneous Coronary Intervention
Standard of care
Device: Retriever Thrombectomy
The SolitaireTM X revascularisation device is a self-expanding stent designed for dynamic clot integration with radiopaque markers that enhance visualisation of the optimal working length. After a thrombotic occlusion has been identified and crossed with a guidewire, the stent-retriever thrombectomy proceeds. A microcatheter (e.g., PhenomTM, MarksmanTM) is advanced over the guidewire and once it has traversed the thrombotic occlusion, the SolitaireTM X device is advanced through the microcatheter until the usable length of the stent extends past each side of the thrombus in the vessel. As the microcatheter is retracted to the proximal radiopaque marker of the stent, the stent self-expands and entangles the thrombus. The microcatheter and SolitaireTM X Revascularisation Device are withdrawn as a unit into the guide catheter under continuous aspiration. PCI then proceeds driven by clinical decision making and department guidelines.
Other Names:
  • SolitaireTM X Revascularisation Device
  • Stent Retriever

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
MACCE
Time Frame: At 6 months after PCI
At 6 months after PCI
Thrombus Volume (mm^3)
Time Frame: During PCI prior to stent implantation (typically 30 min from start of procedure)
Assessed with Optical Coherence Tomography [OCT]
During PCI prior to stent implantation (typically 30 min from start of procedure)
Device-related Target Vessel Complications
Time Frame: During PCI prior to stent implantation (typically 30 min from start of procedure)
Assessed with angiography and/or OCT
During PCI prior to stent implantation (typically 30 min from start of procedure)
Device Deficiency
Time Frame: During PCI prior to stent implantation (typically 30 min from start of procedure)
Assessed with angiography and/or OCT
During PCI prior to stent implantation (typically 30 min from start of procedure)
Major Adverse Cardiac and Cerebrovascular Events (MACCE)
Time Frame: Up to 30 days after PCI
Up to 30 days after PCI

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Flow Volume (mm^3)
Time Frame: During PCI prior to stent implantation (typically 30 min from start of procedure)
Assessed with OCT
During PCI prior to stent implantation (typically 30 min from start of procedure)
Thromboatheroma Volume (mm^3)
Time Frame: Post-stent implantation during PCI (typically 50 min after procedure start)
Assessed with OCT
Post-stent implantation during PCI (typically 50 min after procedure start)
Flow Volume (mm^3)
Time Frame: Post-stent implantation during PCI (typically 50 min after procedure start)
Assessed with OCT
Post-stent implantation during PCI (typically 50 min after procedure start)
Number of Participants With Stent Underexpansion & Malapposition
Time Frame: Post-stent implantation during PCI (typically 50 min after procedure start)
Assessed with OCT according to established international consensus criteria.
Post-stent implantation during PCI (typically 50 min after procedure start)
Thrombolysis in Myocardial Infarction (TIMI) Flow
Time Frame: Post-stent implantation during PCI (typically 60 min after procedure start)
Assessed with angiography according to the TIMI Flow criteria
Post-stent implantation during PCI (typically 60 min after procedure start)
Number of Participants With Myocardial Blush Grade (MBG) < 3
Time Frame: Post-stent implantation during PCI (typically 60 min after procedure start)
Assessed angiographically according to the TIMI Myocardial Blush Grade Score Criteria. The scale goes from 0-3. Myocardial blush grade (MGB) of 0, 1 and 2 indicates angiographic malperfusion, whilst a Myocardial blush grade (MGB) score of 3 indicates normal perfusion.
Post-stent implantation during PCI (typically 60 min after procedure start)
Angiograpicy Derived Index of Microcirculatory Resistance
Time Frame: Post-stent implantation during PCI (typically 60 min after procedure start)
The angiography derived index of microcirculatory resistance is a continuous variable that measures microcirculatory resistance. No formal minimum and maximum values exist. The higher the value, the worse the angiographic perfusion. A value over 40U confers an adverse prognosis.
Post-stent implantation during PCI (typically 60 min after procedure start)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Oxford University Hospitals NHS Trust

Collaborators

Medtronic
Terumo Corporation

Investigators

  • Principal Investigator: Giovanni Luigi De Maria, Oxford University Hospitals NHS Trust

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

May 6, 2022

Primary Completion (Actual)

October 24, 2024

Study Completion (Actual)

May 28, 2025

Study Registration Dates

First Submitted

March 2, 2022

First Submitted That Met QC Criteria

March 23, 2022

First Posted (Actual)

April 1, 2022

Study Record Updates

Last Update Posted (Estimated)

September 5, 2025

Last Update Submitted That Met QC Criteria

September 3, 2025

Last Verified

September 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 15488

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

There is no plan to make IPD available to other researchers unless requested and upon the discretion of the Chief Investigator

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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