Wall Shear Stress and Neointimal Healing Following PCI in Angulated Coronary Vessels
Condition: Coronary Artery Disease
MeSH terms: Coronary Artery Disease
Study type: Interventional

Summary: 
      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.
    

Detailed description: 
      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.
    

Intervention name(s): Resolute Integrity Zotarolimus eluting stent; Xience Xpedition everolimus eluting stent; Optical Coherence Tomography (OCT); Intravascular Ultrasound (IVUS)
Intervention type(s): Device; Device; Device; Device
Intervention description(s): 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.; 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.
Intervention MeSH terms: Everolimus
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Participant)
Primary purpose: Treatment
Keywords: neointimal tissue area; angulated coronary vessels; wall shear stress; zotarolimus eluting stent; everolimus eluting stent