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 Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
SINGLE
Enrollment
81
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 The microcatheter and SolitaireTM X Revascularisation Device are withdrawn as a unit into the guide catheter under continuous aspiration.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.
Standard of care
Standard of care treatment with manual thrombectomy catheter
Oxford Heart Centre
Oxford, United Kingdom
Thrombus Volume (mm^3)
Assessed with Optical Coherence Tomography \[OCT\]
Time frame: During PCI prior to stent implantation (typically 30 min from start of procedure)
Device-related Target Vessel Complications
Assessed with angiography and/or OCT
Time frame: During PCI prior to stent implantation (typically 30 min from start of procedure)
Device Deficiency
Assessed with angiography and/or OCT
Time frame: 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
MACCE
Time frame: At 6 months after PCI
Flow Volume (mm^3)
Assessed with OCT
Time frame: During PCI prior to stent implantation (typically 30 min from start of procedure)
Thromboatheroma Volume (mm^3)
Assessed with OCT
Time frame: Post-stent implantation during PCI (typically 50 min after procedure start)
Flow Volume (mm^3)
Assessed with OCT
Time frame: Post-stent implantation during PCI (typically 50 min after procedure start)
Number of Participants With Stent Underexpansion & Malapposition
Assessed with OCT according to established international consensus criteria.
Time frame: Post-stent implantation during PCI (typically 50 min after procedure start)
Thrombolysis in Myocardial Infarction (TIMI) Flow
Assessed with angiography according to the TIMI Flow criteria
Time frame: Post-stent implantation during PCI (typically 60 min after procedure start)
Number of Participants With Myocardial Blush Grade (MBG) < 3
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.
Time frame: Post-stent implantation during PCI (typically 60 min after procedure start)
Angiograpicy Derived Index of Microcirculatory Resistance
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.
Time frame: Post-stent implantation during PCI (typically 60 min after procedure start)
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