Stents are metallic tubular supports placed inside a blood vessel to relieve an obstruction and restore blood flow to the heart muscle. Stents could also be coated with a drug (drug-eluting stents - DES) that improves local healing and inhibits growth of scar tissue within the vessel that otherwise could lead to re-narrowing. This study will evaluate the effects of 2 FDA-approved metallic stents with different designs that may have important effects on regional plaque response and blood flow dynamics immediately after stent deployment and stent healing at 12 months follow up.
The past two decades have registered major advances in cardiovascular medicine that have improved patients' survival and quality of life. One area of major research and innovation is the field of percutaneous coronary interventions (PCI), a non-surgical procedure used to treat a narrowed heart artery with stents. Stents are metallic tubular supports placed inside a blood vessel to relieve an obstruction and restore blood flow to the heart muscle. Stents could also be coated with a drug (drug-eluting stents - DES) that improves local healing and inhibits growth of scar tissue (smooth muscle and fibrous cells) within the vessel that otherwise could lead to re-narrowing. The investigators study will evaluate two FDA-approved DES, currently in use, with respect to coronary vessel healing and long term patency. These include the XIENCE Xpedition Everolimus drug-eluting stent (X-EES) from Abbott Vascular and Resolute Integrity® Zotarolimus drug-eluting stent (R-ZES) from Medtronic, Inc, both of which have been shown in large clinical trials to be safe and effective. This study will evaluate the effects of apparently subtle differences in stent design between these two platforms that may have important effects on regional plaque response and blood flow dynamics immediately after stent deployment and stent healing and scar formation at 12 months follow up. Several aspect of the R-ZES compared to the X-EES design may result in more favorable regional plaque response and blood flow dynamics immediately after stent deployment. These include a more compliant stent design made of a single sinusoidal wire with no connector between struts that is likely to be more comformable to a curved or angulated coronary vessels. In heart vessels which are not angulated, these features may not make a major difference in outcomes as studies already suggest. Whereas, in narrowed arteries which are curved or angulated, the use of X-EES could result in more straightening of the vessel's natural curvature and more disturbance in flow patterns. In contrast, the use of R-ZES in angulated arteries could cause less hemodynamic disturbances. There is a great deal of data suggesting that disturbances in local blood flow patterns and creation of eddy currents ('turbulent' blood flow) could adversely affect stent healing and exacerbate neointimal tissue growth. Using two intravascular imaging technologies, the optical coherence tomography (OCT) and intravascular ultrasound (IVUS), this study aims to investigate differences in scar tissue coverage within the stented region and the degree of narrowing at the edges of the stent in patients undergoing clinically-indicated PCI (with R-ZES and X-EES) at 12-month follow-up.
PCI with Resolute stent
PCI with Xience stent
Optical coherence tomography (OCT) will be performed at baseline to assess plaque burden prior to and after stent deployment as well as to evaluate stent expansion and stent apposition. OCT will be repeated at one year follow-up to evaluate neo-intimal tissue coverage within the stent and change in plaque area at the stent edges. Offline, manual detection of lumen area and stent area will be performed for each OCT cross-section from baseline and follow up examinations.
Emory University
Atlanta, Georgia, United States
Nanjing Medical University, Nanjing Heart Center
Nanjing, China
Kobe University Graduate School of Medicine
Hyōgo, Japan
In Stent Mean Cross-sectional Area of Neo-intimal Tissue Coverage
Cross-sectional area in neointimal hyperplasia by Optical Coherence Tomography (OCT) at 1 year following stent placement
Time frame: 1 year
In Stent: Mean Thickness of Strut Coverage at Follow up
Mean thickness of strut coverage at follow up (In-Stent safety endpoint). Struts have been considered as covered when tissue overlying the struts is \>0 μm by optical coherence tomography (OCT)
Time frame: 1 year
In-Stent: Degree of Vascular Straightening Post-percutaneous Coronary Intervention (PCI) (In-Stent Mechanistic Endpoint)
post PCI angulation by Angio: In-Stent: Degree of vascular straightening post-percutaneous coronary intervention (PCI) (In-Stent mechanistic endpoint)
Time frame: Immediately after stent implantation
In Stent: Plaque Prolapse Post-PCI (In-Stent Mechanistic Endpoint)
Plaque will be identified by Optical Coherence Tomography (OCT)- In-Stent: Plaque prolapse post-PCI (In-Stent mechanistic endpoint)
Time frame: Immediately after stent implantation
In-Stent: Percent Area of Low Wall Shear Stress (WSS)-(In-Stent Mechanistic Endpoint)
The % area of low wall shear stress immediately after stent implantation will be measured by Optical Coherence Tomography (OCT)
Time frame: Immediately after stent implantation
Stent Edge -Change in Plaque Area (Efficacy Endpoint) at 5 mm Proximal and Distal to Stent.
Change in plaque area at the stent edges will be calculated from the change in plaque area in the 5 mm proximal and distal segments by intravascular ultrasound (IVUS); calculated as follow-up values minus baseline values
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Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
SINGLE
Enrollment
86
Intravascular ultrasound (IVUS) will be performed at baseline to assess plaque burden prior to and after stent deployment as well as to evaluate stent expansion and stent apposition. IVUS will be repeated at one year follow-up to evaluate neo-intimal tissue coverage within the stent and change in plaque area at the stent edges. Offline, manual detection of lumen area, stent area, vessel area (external elastic membrane) and the media-adventitia interface will be performed for each IVUS cross-section from baseline and follow up examinations.
Wakayama Medical University Department of Cardiovascular Medicine
Wakayama, Japan
Latvian Society of Cardiology Pauls Stradins Clinical University Hospital
Riga, Latvia
University Clinical Center of Serbia
Belgrade, Serbia
Seoul National University College of Medicine
Seoul, South Korea
Samsung Medical Center, Sungkyunkwan University School of Medicine Division of Cardiology
Seoul, South Korea
Ulsan University Hospital University of Ulsan College of Medicine
Ulsan, South Korea
Hospital Clinico San Carlos, Universidad Complutense de Madrid
Madrid, Spain
Time frame: 1 year
Stent Edge: Degree of Vascular Straightening Post-percutaneous Coronary Intervention (PCI) at the Stent Edges (Stent Edge Mechanistic Endpoint)
Degree of vascular straightening post-percutaneous coronary intervention (PCI) at the stent edges (Stent Edge mechanistic endpoint) will be measured post PCI angulation by Angio
Time frame: Immediately after stent implantation
Stent Edge: Percent Area With Low Wall Shear Stress (WSS) at Stent Edges Post-PCI (Mechanistic Endpoint)
The % area of low wall shear stress in the 5 mm proximal and distal segments immediately after stent implantation will be measured by intravascular ultrasound (IVUS).
Time frame: Immediately after stent implantation