Coronary Microcirculatory and Bioresorbable Vascular Scaffolds

Study Overview
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Brief Summary
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Angina and heart attacks are caused by narrowings in the coronary arteries (blood vessels) supplying the heart. These narrowings can be opened using a balloon and stent (angioplasty). Traditionally, stents are constructed from metal and are permanent. However, newer stents are being constructed from carbohydrate polymers (scaffolds), which allow them to reabsorb over time leaving no permanent implant. New data has suggested that these scaffolds appear to reduce recurrent angina and may alter the blood flow down the artery. However, it is not known whether this is due to the scaffolds themselves or the way the scaffolds are inserted. In this study we hope to measure the blood flow to the heart and assess changes in that flow during stent and scaffold insertion. It is also important to know whether these effects are durable and thus, a cohort of patients will return at 3-months to be restudied. These data are important to help us understand why blood flow is affected by stent/scaffold selection or device implantation technique and whether this results in better long-term outcomes.

Official Title
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Evaluation of Microcirculatory Protection In Percutaneous REvascularisation With Bioresorbable Vascular Scaffolds Versus Metallic Drug-eluting Stents: a Device- and Implant Technique-based Comparison

Conditions
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CHD - Coronary Heart Disease, Angina, Stable, Myocardial Ischemia

Intervention / Treatment
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* Device: Bioresorbable Vascular Scaffolds (BVS)
* Device: Drug-Eluting Stent (DES) - slow
* Device: Drug-Eluting Stent (DES) - standard(std)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patient age >18 years, <75 years. Lesion suitability for BVS deployment: target vessel calibre >2.3mm and <3.8mm reference diameter, without significant tortuosity or calcification. Listed for single-vessel PCI procedure. Lesion length≤28mm (to accommodate single BVS/DES) Preserved left ventricular ejection fraction (EF≥50%). Exclusion Criteria: Patients with confirmed myocardial infarction within the preceding 2 months. Allergy or intolerance to aspirin, clopidogrel, prasugrel or ticagrelor or contraindication to 12 months' dual antiplatelet therapy. Contraindication to use of adenosine (asthma/chronic lung disease with documented bronchoreactivity). Significant known comorbidity or terminal condition with life expectancy <6 months. Pregnancy. Coagulopathy or warfarin treatment. Significant renal impairment (baseline creatinine>130 mmol/l). Other comorbid condition that may affect microcirculatory function or troponin release (eg. Seropositive inflammatory conditions). Inability to comply with follow-up requirements. Target lesion in left mainstem, saphenous vein or arterial grafts. Chronic total occlusion.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 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: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: DES-std group<br>(DES: drug-eluting stent). Metallic DES implanted in standard fashion. To be compared with the DES-slow group at interim analysis at the end of phase 1 stage. | Device: Drug-Eluting Stent (DES) - standard(std)<br>* Metallic DES implanted in standard fashion. To be compared with the DES-slow group at interim analysis at the end of phase 1 stage.<br>* Other names: Xience;|
| Experimental: DES-slow group<br>(DES: drug-eluting stent). Slow device inflation (mandated in the BVS IFU). To be compared with the DES-std group at interim analysis at the end of phase 1 stage. After the interim analysis DES-slow to be compared with BVS. | Device: Drug-Eluting Stent (DES) - slow<br>* Slow device inflation (mandated in the BVS IFU). To be compared with the DES-std group at interim analysis at the end of phase 1 stage. After the interim analysis DES-slow to be compared with BVS.<br>* Other names: Xience;|
| Experimental: BVS group<br>(Bioresorbable Vascular Scaffold) Introduced after the interim analysis (phase 2) for comparison with DES-slow. | Device: Bioresorbable Vascular Scaffolds (BVS)<br>* Bioresorbable Vascular Scaffold. Introduced after the interim analysis (phase 2) for comparison with DES-slow.<br>* Other names: ABSORB;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in IMR between baseline and post-stent/scaffold implantation. | IMR: index of microvascular resistance | During procedure | 
| Change in CFR between baseline and post-stent/scaffold implantation. | CFR: coronary flow reserve | During procedure | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of troponin elevation post-PCI (MI4a). | Measuring serum troponin I levels by blood test | Measured 6 hours after stent insertion | 
| Changes in IMR between baseline, post-implant and subsequent timepoints in subrandomized group. | IMR: index of microvascular resistance | 3 months follow up | 
| Incidence of post-PCI angina and quality of life by standardized Seattle angina questionnaire at telephone follow-up. | Description: The Seattle Angina Questionnaire is a points based question and answer system where a overall score can be assessed and compared | Up to 12 months | 
| Incidence of stent & scaffold expansion & malapposition adjudged by strut-level OCT analysis. | OCT analysis of stent struts done quantitatively | During index procedure and at 3 month follow up | 
| Incidence of stent/scaffold strut coverage/endothelialisation adjudged by strut-level OCT analysis. | OCT analysis of stent struts done quantitatively | During index procedure and at 3 month follow up | 
| Nature/phenotype of underlying target lesion plaque by OCT analysis. | OCT analysis of lesion characteristics done quantitatively | During index procedure and at 3 month follow up | 
| Adverse events | Adverse event assessed by clinical history and medical notes | At time points 1, 3, 6 & 12 months post-PCI | 
| Serious adverse events | Serious adverse event assessed by clinical history and medical notes | At time points 1, 3, 6 & 12 months post-PCI | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Coronary Stent, PCI, BVS, Index of microcirculatory resistance