Multicentre Radial Artery Patency Study: Results of Patency Beyond 5 Years After Coronary Artery Bypass Surgery
Condition: Coronary Artery Disease
MeSH terms: Coronary Artery Disease; Myocardial Ischemia; Coronary Disease
Study type: Interventional
Phase: Phase 3

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.
    

Detailed 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.
    

Intervention name(s): Radial Artery and Saphenous Vein Grafts Randomized to either right coronary or left circumflex coronary artery territories
Intervention type(s): Procedure
Intervention description(s): 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.
Allocation: Randomized
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Coronary Bypass Surgery; Coronary Artery Disease; Angiography; Arterial Grafts; Radial Artery; Saphenous Vein