title: Native coronary artery patency after coronary artery bypass surgery.
abstract: OBJECTIVE
  The aim of the study was to determine native coronary artery patency 1 year after coronary artery bypass grafting and to identify clinical and angiographic predictors for the development of a chronic total occlusion (CTO).
  
  
  BACKGROUND
  In contrast to the large body of information regarding graft patency, data regarding atherosclerosis progression and vessel patency in surgically bypassed native coronary arteries are less clear.
  
  
  METHODS
  Of the 440 patients who underwent 1-year follow-up angiography as part of the multicenter RAPS (Radial Artery Patency Study), included in our study were 388 patients (88%) for whom angiograms were available for review. Angiograms were reviewed for native coronary artery patency in an independent blinded manner.
  
  
  RESULTS
  On the pre-operative angiogram, CTO of at least 1 native coronary vessel was demonstrated in 240 patients (61.9%) having 305 occluded vessels. At 1 year after coronary artery bypass grafting, at least 1 new native coronary artery CTO occurred in 169 patients (43.6%). In 7.5% of patients, the native artery and the graft supplying that territory were both occluded. A new CTO was almost 5 times more likely to occur in coronary vessels with a pre-operative proximal stenosis >90% compared with vessels with proximal stenosis <90% (45.5% vs. 9.5%, respectively, p < 0.001). Patients with a new CTO had significantly more baseline Canadian Cardiovascular Society class 4 angina compared with patients without a new CTO. A new CTO was less likely to occur in the left anterior descending artery (18.4%), supplied by the left internal thoracic artery. When comparing radial artery and saphenous vein grafts, neither the type of graft nor graft patency had any association with native coronary artery occlusion.
  
  
  CONCLUSIONS
  CTO of surgically bypassed coronary arteries 1 year after coronary artery bypass grafting is extremely common.
authors: Division of Cardiology, Schulich Heart Program, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
authors: David
authors: D
authors: Pereg
authors: Division of Cardiology, Schulich Heart Program, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada; Leviev Heart Center, Sheba Medical Center, Tel Aviv University, Tel Hashomer, Israel.
authors: Paul
authors: P
authors: Fefer
authors: Division of Cardiology, Schulich Heart Program, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
authors: Michelle
authors: M
authors: Samuel
authors: Division of Cardiology, Schulich Heart Program, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
authors: Rafael
authors: R
authors: Wolff
authors: Division of Cardiology, Schulich Heart Program, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
authors: Andrew
authors: A
authors: Czarnecki
authors: Division of Cardiovascular Surgery, Schulich Heart Program, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.
authors: Saswata
authors: S
authors: Deb
authors: Division of Cardiology, Schulich Heart Program, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
authors: John D
authors: JD
authors: Sparkes
authors: Division of Cardiovascular Surgery, Schulich Heart Program, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada; Bernard S. Goldman Chair in Cardiovascular Surgery, Sunnybrook Health Sciences Center, University of Toronto, Toronto, Ontario, Canada.
authors: Stephan E
authors: SE
authors: Fremes
authors: Division of Cardiology, Schulich Heart Program, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada; Reichmann Chair in Cardiovascular Sciences, Sunnybrook Health Sciences Center, University of Toronto, Toronto, Ontario, Canada. Electronic address: Bradley.strauss@sunnybrook.ca.
authors: Bradley H
authors: BH
authors: Strauss
mesh_terms: D000368:Aged; D002908:Chronic Disease; D017023:Coronary Angiography; D001026:Coronary Artery Bypass / Q000009:adverse effects* / Q000379:methods; D003324:Coronary Artery Disease / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D054059:Coronary Occlusion / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D016208:Databases, Factual; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D017534:Radial Artery / Q000637:transplantation; D012307:Risk Factors; D012501:Saphenous Vein / Q000637:transplantation; D013997:Time Factors; D016896:Treatment Outcome; D014654:Vascular Patency
keywords: coronary artery bypass grafting; coronary artery disease