Try our beta test site
IMPORTANT: Listing of a study on this site does not reflect endorsement by the National Institutes of Health. Talk with a trusted healthcare professional before volunteering for a study. Read more...

A Study to Examine the Implantation Characteristics of Two Drug-Eluting Stents (ORCA-2)

This study has been completed.
Information provided by:
Royal Brompton & Harefield NHS Foundation Trust Identifier:
First received: August 24, 2010
Last updated: July 11, 2011
Last verified: July 2011

Despite recent advances in stent technology and clot reducing drug therapy, acute stent occlusion or thrombosis (ST), still occurs and can be life threatening. It has been shown that certain features of how the stent relates to the artery wall may predict ST. One such feature, so-called stent strut malapposition (SSM), can be assessed after implantation but current imaging techniques are relatively unreliable. Optical Coherence Tomography (OCT) is a newer technology that can be performed safely and easily after angioplasty and may allow the stent struts to be assessed more accurately and reliably.

This study will use OCT to examine how two different types of commonly used drug-eluting stents relate to the artery wall. The Xience V (Abbott Vascular, USA) stent has thinner struts and a more open frame than the Cypher (Cordis, USA) stent. We hypothesise therefore that the potentially more pliable structure of the Xience V stent will be associated with greater contact with the vessel wall. This may have a bearing on the relative rate of SSM, although large studies have shown the rate to be low in both the Cypher and the Xience V stent. We believe that OCT imaging of SSM and symmetry of the stent immediately after angioplasty will compliment conventional visual assessment and may identify those patients in whom further improvement of stent with a balloon is necessary.

This study will involve the random allocation of forty patients requiring coronary angioplasty to one of the Cypher or Xience V stent. The procedure will be performed in the usual manner as indicated clinically and will include imaging of the stented artery segment with OCT once the operator is satisfied with the visual result by angiography.

Condition Intervention
Coronary Artery Disease
Device: Coronary Stent Cypher
Device: Coronary stent Xience

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: Comparison of Rates of Strut Malapposition Between Everolimus and Sirolimus Eluting Stents - A Randomised Optical Coherence Tomography Study

Further study details as provided by Royal Brompton & Harefield NHS Foundation Trust:

Primary Outcome Measures:
  • Stent strut malapposition (SSM) [ Time Frame: Immediate post stent deployment during the same angiographic procedure within 60 minutes ]
    SSM will be quoted as the percentage of malapposed stent struts as a proportion of the total number of struts analysed within each stent group.

Secondary Outcome Measures:
  • Stent eccentricity index (SEI) [ Time Frame: Immediate post stent deployment during the same angiographic procedure within 60 minutes ]
    This is a commonly used measure that is designed to quantify the uniformity and symmetry of the stent after it has been deployed in the coronary artery. It is calculated as the minimum diameter of the stent divided by the maximum diameter of the stent at a preset point. The mean SEI will be compared between two stent type groups.

  • Degree of stent embedding [ Time Frame: Immediate post stent deployment during the same angiographic procedure within 60 minutes ]
    This relates to what degree, if at all, the stent strut is 'buried' within the coronary artery wall. The proportion of each strut that is buried or embedded will be calculated and then averaged for each stent group. A strut that is buried in the vessel wall for more than half its thickness will be defined as 'embedded'.

Estimated Enrollment: 40
Study Start Date: September 2010
Study Completion Date: July 2011
Primary Completion Date: July 2011 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Cypher™ Stent
Participants in the Cypher arm will be randomised to receive a Cypher™ (Cordis, Miami Lake, USA) coronary stent
Device: Coronary Stent Cypher
The angioplasty will then be performed in a usual fashion in accordance with the operator's discretion and local protocols.
Active Comparator: Xience™ Stent
Patients in the Xience™ arm will receive a Xience™ Stent(Abbott Vascular, Santa Clara, USA.
Device: Coronary stent Xience
The angioplasty will then be performed in a usual fashion in accordance with the operator's discretion and local protocols


Ages Eligible for Study:   18 Years to 90 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Presence of a coronary artery stenosis undergoing percutaneous coronary intervention and stenting (PCI).
  • Eligibility for drug eluting stent (DES) deployment.
  • Stable or unstable coronary syndrome presentation, including ST elevation myocardial infarction (STEMI).
  • Aged 18-90

Exclusion Criteria:

  • Contraindication to the use of a DES.
  • Target lesion located within previous stent (in stent restenosis).
  • Sustained haemodynamic instability following stent deployment (Systolic BP 90≤ mmHg or sustained ventricular arrhythmia).
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01201369

United Kingdom
Harefield Hospital
Harefield, Middlesex, United Kingdom, UB96JH
Sponsors and Collaborators
Royal Brompton & Harefield NHS Foundation Trust
Principal Investigator: Miles CD Dalby, MD, MRCP Consultant Cardiologist, The Royal Brompton & Harefield NHS Foundation Trust
Study Director: Robert D Smith, MD, MRCP The Royal Brompton & Harefield NHS Foundation Trust
  More Information

Responsible Party: Dr Miles Dalby, Consultant Cardiologist, Royal Brompton & Harefield NHS Foundation Trust Identifier: NCT01201369     History of Changes
Other Study ID Numbers: ORCA-2
Study First Received: August 24, 2010
Last Updated: July 11, 2011

Keywords provided by Royal Brompton & Harefield NHS Foundation Trust:
Percutaneous Coronary Intervention
Coronary Artery Stenosis
Acute Myocardial Infarction
Coronary Artery Stent
Optical Coherence Tomography

Additional relevant MeSH terms:
Coronary Artery Disease
Myocardial Ischemia
Coronary Disease
Heart Diseases
Cardiovascular Diseases
Arterial Occlusive Diseases
Vascular Diseases processed this record on May 25, 2017