Optimizing Infarct Size by Transforming Emergent Stenting Into an Elective Procedure Study

Study Overview
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Brief Summary
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The goal of primary PCI is to restore anterograde myocardial flow. Stenting a largely thrombotic lesion may determine distal embolisation of thrombotic material therefore deteriorating myocardial perfusion.

Detailed Description
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In the setting of largely thrombotic lesions such as those treated in the context of primary PCI, stenting often results in distal micro and macro-embolisation which hampers coronary flow and microvascular recovery. Interestingly in some of these studies comparing BMS versus balloon angioplasty an early hazard associated to the use of stent has been reported. Thus, investigators hypothesize in this protocol that refraining from stenting during the acute phase of ST segment myocardial infarction is safe and associated to improved myocardial recovery as compared to acute stenting.

Official Title
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Immediate Versus Delayed Stenting in Patients With ST-Elevation Myocardial Infarction Undergoing Mechanical Intervention

Conditions
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Myocardial Infarction

Intervention / Treatment
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* Procedure: Immediate stenting
* Procedure: Delayed stenting


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: chest pain for >30 min with ST-segment elevation of one mm or more in 2 or more contiguous ECG leads or with presumably new left bundle-branch block admission either within 12 h of symptom onset or between 12 and 24 h with evidence of continuing ischaemia Exclusion Criteria: the exclusion criteria will include history of bleeding diathesis or documented allergy/intolerance or contraindication to clopidogrel or ticlopidine or prasugrel inability to assume an oral P2Y12 receptor blocker on a consecutive daily basis for a minimum of 6 months, or to heparin or aspirin uncontrolled hypertension (systolic or diastolic arterial pressure >180 mmHg or 120, respectively, despite medical therapy) limited life expectancy, e.g. neoplasms, others inability to obtain informed consent pregnancy patients were not enrolled if they were clinically unstable, presented with severe arrhythmia, or had known contraindications to CMR (claustrophobia, pacemakers, or implantable defibrillator devices)

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: Immediate stenting<br>Patients being randomized to the immediate stenting arm will be managed according to the guidelines. Irrespective of TIMI flow at presentation, investigators will be requested to thrombus aspirate immediately after successful wiring of the culprit vessel followed by direct stenting. In cases where insertion of thrombus removal catheter and/or direct stenting is not successful, balloon angioplasty will be allowed. | Procedure: Immediate stenting<br>* Primary coronary stenting<br>|
| Experimental: Delayed stenting<br>Patients being randomized to the delayed/staged stenting arm will be managed with the aim to obtain stable TIMI 3 flow with no considerations given at the percentage of residual stenosis at the culprit lesion. In patients presenting with TIMI 3 flow, investigators will be left free to wire the vessel and proceed to thrombus aspiration to decrease thrombus burden in the culprit lesion or to leave the vessel untreated at the time of index PCI. Patients presenting with suboptimal TIMI flow (i.e. less than 3), investigators are required to wire the vessel and thrombus aspirate. If stable (persisting for at least 5 minutes) TIMI 3 flow is obtained, investigators are requested to stop the procedure. The goal is to achieve s table TIMI 3 flow with no considerations given to the percentage of residual stenosis. Stenting in this arm will be allowed only on a bail-out strategy. | Procedure: Delayed stenting<br>* Coronary stenting 3 to 7 days after having reopened the vessel in the acute phase<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Myocardial blush grade (MBG) equal or greater than 2 | The MBG will be estimated visually by 2 experienced observers, as previously described. | post-procedure | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| ST segment elevation resolution | Cumulative ST segment elevation in all leads will be quantified before and after the procedure and expressed as percentage | 30 minutes after the procedure | 
| ST segment elevation Resolution |  | 90 minutes after the procedure | 
| infarct size | Infarct size will be quantified by MRI | 5 days | 
| Infarct size | Infarct size will be quantified by MRI | 6 months | 
| microvascular obstruction | microvascular obstruction will be quantified by MRI | 5 days | 
| microvascular obstruction | microvascular obstruction will be quantified by MRI | 6 months | 
| Mortality | overall and cardiac mortality will be assessed up to 6 months | 6 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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ST-segment elevation myocardial infarction, Primary angioplasty, stent