RETRIEVE-AMI Study

Not Applicable

Completed

Brief Summary: 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.

Recruitment & Eligibility

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

Primary Outcome Measures

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

Secondary Outcome Measures

Name	Time	Method
Flow Volume (mm^3)	Post-stent implantation during PCI (typically 50 min after procedure start)	Assessed with OCT
Thromboatheroma Volume (mm^3)	Post-stent implantation during PCI (typically 50 min after procedure start)	Assessed with OCT
Number of Participants With Stent Underexpansion & Malapposition	Post-stent implantation during PCI (typically 50 min after procedure start)	Assessed with OCT according to established international consensus criteria.
Thrombolysis in Myocardial Infarction (TIMI) Flow	Post-stent implantation during PCI (typically 60 min after procedure start)	Assessed with angiography according to the TIMI Flow criteria
Number of Participants With Myocardial Blush Grade (MBG) < 3	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.
Angiograpicy Derived Index of Microcirculatory Resistance	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.