The Impact of Post Stenting Balloon Dilatation on Coronary Microcirculation in STEMI Patients Undergoing PPCI

Study Overview
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Brief Summary
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This study aims to assess the impact of NC balloon post-dilatation on coronary microcirculation in patients with ST segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI).

Detailed Description
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Suboptimal stent deployment can lead to future stent failure. Thus, optimising stent deployment with non-compliant balloons (NC balloon) post dilatation (PD) at high pressures is an established strategy. In the context of ST segment elevation myocardial infarction (STEMI), PD has been correlated anecdotally with the no reflow phenomenon. This study aims to determine the impact of stent post-dilation (PD) with NC balloons at high pressures on coronary microcirculation during PPCI by measuring the index of microcirculatory resistance (IMR) pre and post stent post-dilatation. Pre and post PD, an optical coherence tomography (OCT) study will be performed to assess stent deployment and identify parameters that predict the changes in IMR.

Official Title
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The Impact of Post Stenting Balloon Dilatation on Coronary Microcirculation in ST Segment Elevation Myocardial Infarction (STEMI) Patients Undergoing Primary Percutaneous Coronary Intervention (PPCI)

Conditions
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ST-elevation Myocardial Infarction (STEMI)

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria >18 years of age Acute symptoms onset with duration > 20 minutes ST-segment elevation ≥ 0.1 mV in ≥ 2 contiguous leads, signs of a true posterior infarction or documented newly developed left bundle branch block Infarct related artery with a diameter above 2.5 mm Operator's intention to proceed to stent deployment (i.e. not refer for CABG or defer PCI) Exclusion Criteria < 18 year of age Symptoms duration > 12 hours Unable to give informed consent Previous bypass graft surgery Previous myocardial infarction Pregnancy Known severe chronic kidney disease (creatinine clearance ≤30 mL/min), unless the patient is on dialysis Unable to receive antiplatelets or anticoagulation (i.e. coagulation disorders, bleeding etc.) Haemodynamic instability Severe LMS disease Culprit vessel diameter < 2.5 mm Contraindications to adenosine Any study lesion characteristic resulting in the expected inability to deliver OCT catheter to the lesion pre and post PD (e.g. moderate or severe vessel calcification or tortuosity)

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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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Delta index of microcirculatory resistance (dIMR) | Delta index of microcirculatory resistance (dIMR) [dΙΜΡ = IMR post post-dilation (post IMR) - IMR pre post-dilation (pre IMR)] | index procedure | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Minimum stent area (MSA) | Pre and post dilatation minimum stent area | index procedure | 
| Stent expansion | Pre and post dilatation stent expansion; defined as the minimum stent area divided by the average of proximal and distal reference lumen areas x 100 | index procedure | 
| Stent mal-apposition | Stent mal-apposition pre and post dilatation; defined as a distance between the strut's luminal edge and luminal vessel wall of greater >200 μm for a length >600 μm (appreciable in >3 contiguous frames at a pull-back speed of 20 mm/sec | index procedure | 
| Intra-stent plaque protrusion and thrombus | Pre and post dilatation intra-stent plaque protrusion and thrombus; defined as a mass attached to the luminal surface or floating within the lumen at least 200 μm beyond the luminal edge of a strut | index procedure | 
| Stent edge dissections | Edge dissections pre and post dilatation, further defined as major and minor [major dissections defined as the ones with a dissection flap width greater or equal to 200 μm) | index procedure | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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STEMI, PPCI, post-dilatation, coronary microcirculation