Multicentre Radial Artery Patency Study: Results of Patency Beyond 5 Years After Coronary Artery Bypass Surgery

Coronary Artery Disease Clinical Trial

— RAPS - 5 years  

Official title:

Multicentre Radial Artery Patency Study: Results of Patency Beyond 5 Years After Coronary Artery Bypass Surgery

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00187356
• Other study ID #: CIHR MCT# 52681
• Status: Completed
• Phase: Phase 3
• First received: September 10, 2005
• Last updated: June 4, 2013
• Start date: July 2002
• Est. completion date: October 2010

Study information

• Verified date: June 2013
• Source: Sunnybrook Health Sciences Centre
• Contact: n/a
• Is FDA regulated: No
• Health authority: Canada: Ethics Review Committee
• Study type: Interventional

Clinical Trial Summary

Bypass surgery is often required to treat severe coronary heart disease. Either arteries or veins can be used as bypass grafts. We wish to compare the long-term durability of the saphenous vein from the leg to that of the radial artery from the fore-arm when used as bypass grafts. We are examining how many of these grafts are still functioning beyond 5 years after bypass surgery by performing a coronary angiogram. After 1-year, we found that radial arteries were more likely to be functioning than saphenous veins. We hypothesize that radial arteries will continue to be superior beyond 5 years.

Description:

The multi-centre Radial Artery Patency Study, (RAPS) is a series of longitudinal graft patency studies designed to compare the long-term patency of the radial artery to the saphenous vein. Between 1996 and 2001, 561 patients were intraoperatively randomized to undergo surgery according to one of two strategies: radial-artery grafting to the circumflex territory and saphenous-vein grafting to the right coronary artery or radial-artery grafting to the right coronary artery and saphenous-vein grafting to the circumflex territory. The first study compared the 8-12 month angiographic patency of the radial artery with that of the saphenous vein as a conduit for coronary artery bypass and found that radial arteries were superior. The primary objective of this current study is to determine the beyond 5-year angiographic patency of the radial artery compared with a saphenous vein coronary bypass graft.

HYPOTHESES

1. The angiographic patency of radial artery grafts studied beyond 5 years following surgery exceeds that of saphenous vein grafts.

2. Radial artery conduits studied beyond 5 years postoperatively have less graft disease than saphenous veins.

SAMPLE SIZE We expect to study 350 patients, which will allow us to test for a 35% risk reduction from 23% occlusion rate in saphenous veins to 15% in radial arteries, assuming a 5% within-patient correlation, with 80% power for a 2-tailed alpha of 0.05.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 269
• Est. completion date: October 2010
• Est. primary completion date: September 2010
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 30 Years to 80 Years

Eligibility

Inclusion Criteria:

The patient population consists of patients who were enroled into the original Multicentre Radial Artery Patency Study between November 1996 and January 2001. These included patients undergoing isolated coronary artery bypass surgery less than 80 years of age with 3 vessel coronary disease and left ventricular ejection fraction greater than 35%.

Exclusion Criteria:

Exclusion criteria included 1: Inability to use the radial artery or saphenous vein conduits: a)nonpalpable ulnar arteries or a positive Allen's test, b) an abnormal Doppler study or ultrasonographic study of the arms, c) a history of vasculitis or Raynaud's syndrome, bilateral varicose veins or vein stripping. 2: Conditions that affected the safety of follow-up angiography: a)renal insufficiency (creatinine > 180 umol/L) b)severe peripheral vascular disease precluding femoral access b)coagulopathy or obligatory uninterrupted use of anticoagulants c) known allergy to radiographic contrast media d) women of childbearing potential e) comorbid illness which precludes the use of follow up angiography f) geographically inaccessible for follow up angiography.

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Treatment

Related Conditions & MeSH terms

• Coronary Artery Disease
• Coronary Disease
• Myocardial Ischemia

Intervention

Procedure:
• Radial Artery and Saphenous Vein Grafts Randomized to either right coronary or left circumflex coronary artery territories
Each patient will receive both study grafts (Radial artery and Study Saphenous vein graft). The within-patient randomization scheme will dictate whether the radial goes to the right or circumflex territory. The saphenous vein graft will go to the opposing territory.

Locations

Country	Name	City	State
Canada	University of Alberta	Edmonton	Alberta
Canada	Laval Hospital	Laval	Quebec
Canada	London Health Sciences Centre - UC	London	Ontario
Canada	London Health Sciences Centre - VC	London	Ontario
Canada	Montreal Heart Institute	Montreal	Quebec
Canada	Montreal Jewish General Hospital	Montreal	Quebec
Canada	Ottawa Heart Institute	Ottawa	Ontario
Canada	St. Michael's Hospital	Toronto	Ontario
Canada	Sunnybrook and Women's College HSC	Toronto	Ontario
Canada	Toronto General Hospital	Toronto	Ontario
Canada	Vancouver General Hospital	Vancouver	Ontario
Canada	Manitoba Health Sciences Centre	Winnipeg	Manitoba
New Zealand	Waikato Hospital	Hamilton

Sponsors (2)

Lead Sponsor	Collaborator
Sunnybrook Health Sciences Centre	Canadian Institutes of Health Research (CIHR)

Countries where clinical trial is conducted

Canada,  New Zealand, 

References & Publications (3)

Deb S, Cohen EA, Singh SK, Une D, Laupacis A, Fremes SE; RAPS Investigators. Radial artery and saphenous vein patency more than 5 years after coronary artery bypass surgery: results from RAPS (Radial Artery Patency Study). J Am Coll Cardiol. 2012 Jul 3;60 — View Citation

Desai ND, Cohen EA, Naylor CD, Fremes SE; Radial Artery Patency Study Investigators. A randomized comparison of radial-artery and saphenous-vein coronary bypass grafts. N Engl J Med. 2004 Nov 25;351(22):2302-9. — View Citation

Fremes SE. Multicenter radial artery patency study (RAPS). Study design. Control Clin Trials. 2000 Aug;21(4):397-413. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	The primary endpoint will be the proportion of grafts which are functionally occluded (TIMI flow 0, 1, or 2).		Beyond 5 years after bypass urgery	No
Secondary	a) the proportion of occluded study grafts (TIMI 0)		Beyond 5 years after bypass urgery	No
Secondary	b) the proportion of functionally occluded grafts where proximal stenosis of native vessel is <90% vs >90%		Beyond 5 years after bypass urgery	No
Secondary	c) the proportion of completely occluded grafts where proximal stenosis of native vessel is <90% vs >90%		Beyond 5 years after bypass urgery	No
Secondary	d) proportion of study grafts with string sign		Beyond 5 years after bypass urgery	No

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