Efficacy and Safety of Zotarolimus-eluting Stent Overexpansion With OCT

Study Overview
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Brief Summary
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Investigators aimed to evaluate efficacy and safety of expansion capacity of zotarolimus-eluting durable-polymer stent assessed by optical coherence tomography (OCT) in vitro and vivo study.

Detailed Description
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Single stent implantation (also called provisional stenting) is currently the preferred technique for percutaneous coronary interventions on the majority of unprotected left main (LM) or non-LM bifurcations. During provisional stenting, proximal optimization technique (POT), proved to correct both the proximal main vessel (MV) malapposition and/or optimize the side branch (SB) ostium strut opening for proper wire re-crossing into the distal cell, might be crucial step and may warrant improved long-term clinical outcomes in the setting of major proximal and distal reference vessel size mismatch (like often in LM bifurcation or diffuse tapered long lesion). Recently, second-generation drug-eluting stent (DES) implantation is recommended over BMS for PCI in patients with ischemic heart disease (IHD) due to superior efficacy and safety. However, percutaneous coronary intervention (PCI) with DES for lesion with the discrepancy of proximal and distal reference vessel size, such as LM or non-LM bifurcation lesion, diffuse tapered long lesion, and ectatic or aneurysmal coronary artery, is challenging due to stent optimization because expert consensus recommend that stent diameter is selected by distal reference diameter, which need stent overexpansion for POT. OCT is a utility that can accurately measure reference vessel diameter and lesion length pre-PCI, which is useful for stent optimization by a suitable stent selection and pre- and post-interventional strategies. OCT also demonstrated higher sensitivity to detect stent malapposition, edge dissection, and tissue prolapsed than IVUS post-PCI. Thus, OCT-guided PCI can be helpful to optimize DES implantation in patients with dilated coronary arteries despite the potential limitation of depth penetration and attenuation images by thrombus. Zotarolimus-eluting stent (Resolute Onyx, Medtronic, Santa Rosa, CA, USA) was developed in response to the demand for stents with improved radiographic visibility. It has a novel thin strut composite wire stent platform that is covered with the same zotarolimus-eluting durable polymer coating as its predecessors. The metallic stent platform consists of a composite wire made from a dense platinum-iridium core, which makes the struts radiopaque, and an outer layer of cobalt-chromium alloy. The dense core also allows for reduced strut thickness, which might be associated with a decreased risk of stent thrombosis. Resolute Onyx has been labeled for maximum stent inner diameter by easy crowns platform (2.00-2.5 mm, 6.5 Crowns; 2.75-3.0 mm, 8.5 crowns; 3.5-4.0 mm, 9.5 crowns; 4.5-5.0 mm; 10.5 crowns). However, safety and efficacy of DES overexpansion is still concerned as safety of efficacy of there are limited data regarding Resolute Onyx overexpansion in vivo and in vitro. This study aims to evaluate the safety and efficacy of Resolute Onyx overexpansion for lesion with the discrepancy between proximal and distal reference vessel which need stent overexpansion for POT, assessed by OCT, providing high-resolution (10 µm) imaging which enables the detection of strut fracture, malapposition.

Official Title
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In vitrO and Vivo Study of assessmeNt for Efficacy and safetY of Zotarolimus-eluting Stent OVERexpansion With Optical Coherence Tomography

Conditions
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Coronary Artery Disease, Optical Coherence Tomography, Stent

Intervention / Treatment
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* Device: Optical coherence tomography-guided percutaneous coronary intervention
* Device: Optical coherence tomography-guided Onyx expansion


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients, ≥19 years of age, who were diagnosed with IHD requiring stent implantation for lesion with size discrepancy between proximal and distal reference diameter over 1mm, such as tapered long lesion or bifurcation lesion, confirmed by OCT The decision to participate voluntarily in this study and the written consent of the patient Exclusion Criteria: Patients with hypersensitivity or contraindication to antiplatelet treatment Female of childbearing potential, who possibly plans to become pregnant any time after enrollment into this study. Patients with a life expectancy shorter than 1 year

Ages Eligible for Study
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Minimum Age: 19 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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| In vivo<br>OCT examination is performed using a frequency-domain OCT system (C7 DragonflyTM OPTISTM Imaging Catheter, Abbott Vascular, Santa Clara, CA, USA) with a 5.4 or 7.5 cm total pullback length according to a non-occlusive technique. The procedure is performed via radial or femoral access with a ≥6 Fr guiding catheter. The OCT catheter is advanced over the 0.014-inch PCI wire and the implanted stent was crossed after administration of intracoronary nitrates of 200 µg. For blood clearing, contrast media was injected through the guiding catheter with an automated power injector. The standard infusion rate was 4 mL/s for 4 seconds with 250 PSI. Follow-up OCT image acquisition was achieved with the same method. After post-PCI OCT, we evaluate the factor regarding post-PCI optimization target by European Expert Consensus. | Device: Optical coherence tomography-guided percutaneous coronary intervention<br>* OCT examination is performed using a frequency-domain OCT system (C7 Dragonfly OPTIS Imaging Catheter, Abbott Vascular, Santa Clara, CA, USA) with a 5.4 or 7.5 cm total pullback length according to a non-occlusive technique. The procedure is performed via radial or femoral access with a ≥6 Fr guiding catheter. The OCT catheter is advanced over the 0.014-inch PCI wire and the implanted stent was crossed after administration of intracoronary nitrates of 200 µg. For blood clearing, contrast media was injected through the guiding catheter with an automated power injector. The standard infusion rate was 4 mL/s for 4 seconds with 250 PSI. Follow-up OCT image acquisition was achieved with the same method. After post-PCI OCT, we evaluate the factor regarding post-PCI optimization target by European Expert Consensus.<br>* Other names: Zotarolimus-eluting stent (Resolute OnyxTM, Medtronic, Santa Rosa, CA, USA);|
| In vitro<br>In vitro study with phantom tube model regarding tapered vessel type | Device: Optical coherence tomography-guided Onyx expansion<br>* Expansion of 2.25, 3.0, and 4.0 mm Resolute Onyx @ nominal pressure OCT pullback Expansion with over 0.5mm sized non-compliant balloon of each stent OCT pullback Expansion with over 1.0mm sized non-compliant balloon of each stent OCT pullback Expansion with over 1.25 1.5mm sized non-compliant balloon of each stent OCT pullback Evaluation of polymer status with overexpansion assessed by an electric microscope<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Maximal stent overexpansion (%) | defines as the ratio of the maximal stent diameter to each diameter of stent | Through procedure completion, up to 24 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Stent strut fracture | defines as none or fewer visible stent strut on the cross-sectional view by performing OCT within stented segments (In in vivo and in vitro groups) | Through procedure completion, up to 24 hours | 
| Absolute average stent diameter (mm) in the maximal stent expansion site | Absolute average stent diameter (mm) in the maximal stent expansion site ((In in vivo and in vitro groups) | Through procedure completion, up to 24 hours | 
| Grade of polymer damage assessed by electron microscope | Grade of polymer damage assessed by electron microscope (In in vitro group) | Through procedure completion, up to 1-month | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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coronary artery disease, optical coherence tomography, stenting