Deferred Stent Trial in STEMI

Study Overview
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Brief Summary
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During primary PCI, stent deployment and post-dilatation are associated with no-reflow. The mechanisms for no reflow include distal embolization of thrombus, enhanced thrombus formation and vascular spasm. No reflow is associated with risk factors such as prolonged duration of ischaemia, heavy thrombus burden, persistent ST elevation and long stent length. ACTIVE HYPOTHESIS: once normal antegrade flow has been re-established with initial aspiration thrombectomy and/or balloon angioplasty at the beginning of primary PCI, compared with usual care with direct stenting, a strategy of deferred stenting for 4 -16 hours to permit the beneficial effects of normalized coronary blood flow and anti-thrombotic therapies will reduce the incidence of no reflow in at-risk STEMI patients. DESIGN: In consecutive STEMI patients with risk factors for no reflow and who have given informed consent, when normal flow has been established (TIMI 3) by initial aspiration thrombectomy and/or balloon angioplasty, participants will be randomized to deferred stenting or usual care with direct stenting. All patients will receive dual anti-platelet therapy. Patients who are randomized to deferred stenting will receive intravenous glycoprotein IIbIIIa inhibitor and anti-coagulation with low molecular weight heparin. Patients who are screened and not eligible to be randomized will be prospectively entered into a registry. Study assessments for feasibility, safety and efficacy will be prospectively performed. An independent clinical event committee will review all serious adverse events. Study endpoints will be subject to core laboratory analyses. The study is intended to inform the design of a larger multicentre clinical trial.

Official Title
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Randomised Controlled Study to Assess Whether Deferred Stenting in Acute STEMI Patients Might Reduce the Incidence of No-reflow Versus Conventional Treatment With Immediate Stenting

Conditions
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ST-Elevation Myocardial Infarction

Intervention / Treatment
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* Procedure: Deferred stenting
* Procedure: Conventional treatment


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Rescue PCI Prolonged ischaemic time (> 12hours) Previous MI Age > 65 Occluded artery (TIMI 0/1) at initial angiography Thrombus burden (TIMI grade 2+) Long plaque/ stent length (> 24 mm) Severe coronary artery disease (e.g calcified artery) Small reference vessel diameter (< 2.5 mm) Persistent ST-elevation (> 50%) following reperfusion Index of microvascular resistance (IMR) > 40 Exclusion Criteria: Absence of normal coronary flow (TIMI 3)

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Deferred stenting<br>During primary PCI in STEMI, when TIMI 3 flow has been re-established with guide-wire, aspiration thrombectomy and/or balloon angioplasty, stenting is then deferred for a period of 4-16 hours following reperfusion. During this time, patients remain in the Coronary Care Unit and will receive intravenous tirofiban and subcutaneous low molecular weight heparin (enoxaparin 1 mg/kg) | Procedure: Deferred stenting<br> <br> |
| Sham Comparator: Conventional treatment<br>Conventional treatment in STEMI, with immediate stenting | Procedure: Conventional treatment<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of angiographic no-reflow/ slow-reflow (TIMI flow grade < 3) in the deferred and conventional treatment groups |  | Asessed during the 1st (both groups) and 2nd procedures (deferred group) (0-16 hours) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Extent of late microvascular obstruction (MVO) assessed by cardiac MRI |  | MRI 2-5 days post randomisation | 
| Clinical events (hospitalisation for heart failure, re-infarction, cardiac death) |  | Assessed at index admission and 6-months | 
| Degree of ST-segment resolution on ECG |  | ECG in cath-lab prior to reperfusion and again 60 mins post-reperfusion | 
| TIMI coronary arter flow grade |  | At the beginning and end of the first procedure (for both groups) and at the beginning and end of the second procedure in the deferred group | 
| Culprit vessel dimensions (QCA) and thrombus burden |  | Initial coronary angiogram (and 2nd angiogram in deferred group) | 
| Change in LV ejection fraction |  | Cardiac MRI 2 days and 6-months post PCI | 
| Index of microvascular resistance (IMR) |  | Assessed following stent deployment (initial procedure for the conventional group and 2nd procedure for the deferred group) | 
| Corrected TIMI frame count |  | At the beginning and end of the first procedure (for both groups) and at the beginning and end of the second procedure in the deferred group | 
| Angiographic tissue myocardial blush grade |  | Angiographic myocardial blush grade at the end of the first procedure (both groups) and at the end of the second procedure in the deferred group | 
| Intra-procedural thrombotic events |  | Asessed during the 1st (both groups) and 2nd procedures (deferred group) (0-16 hours) | 
| Degree of adverse remodelling (end-systolic and end-diastolic volume index) |  | Cardiac MRI at 6-months | 
| Final infarct size and myocardial salvage |  | Assessed from cardiac MRI day 2-5 and cardiac MRI at 6months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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STEMI, No-reflow, Primary percutaneous intervention, Deferred stenting