title: [Patency of Coronary Artery Bypass Graft].
abstract: BACKGROUND
  Coronary heart disease is the leading cause of death and disability in the U.S. and Europe. When significant, the coronary disease can be treated medically or surgically. The medical treatment is performed in the catheterization laboratory and consists in the re-permeabilization of the coronary arteries by percutaneous approach, whereas the surgical myocardial revascularization consists in performing aorto-coronary bypass using arterial or venous conduits.
  
  
  OBJECTIVE
  This study is sought to assess the patency and longevity of bypass in patients requiring new catheterization after surgery for recurrence of ischemic heart disease and to evaluate its relationship with factors such as the type of bypass, cardiovascular risk factors and left ventricular ejection fraction.
  
  
  METHODS
  This study retrospectively analysed a sample of 260 surgically revascularized patients who required a new catheterization at the Hospital of Vila Nova de Gaia - Espinho between 2007 and 2012, for recurrence of ischemic heart disease. The degree of patency of the bypass was evaluated and sought a relationship with other variables such as gender, age, cardiovascular risk factors, left ventricular ejection fraction, the time interval between bypass surgery and the new catheterization.
  
  
  RESULTS
  The patency of the arterial bypass using the left internal mammary artery proved to be superior to the venous conduit bypass. There was no statistically significant relationship between the patency of the bypass, the cardiovascular risk factors and the left ventricle ejection fraction.
  
  
  CONCLUSIONS
  In this study we found a greater patency of the arterial bypass compared to the venous bypass.
authors.affiliation: Instituto de Ciências Biomédicas da Universidade do Porto, Serviço de Cirurgia Cardiovascular do Centro Hospitalar de Vila Nova de Gaia/Espinho e Serviço de Cardiologia do Centro Hospitalar do Porto, Portugal.
authors.forename: Ana
authors.initials: A
authors.lastname: Falcão
authors.forename: Nelson
authors.initials: N
authors.lastname: Santos Paulo
authors.forename: Henrique
authors.initials: H
authors.lastname: Cyrne Carvalho