title: Role of coronary collaterals in off-pump and on-pump coronary bypass surgery.
abstract: BACKGROUND
  Collaterals limit infarct size, preserve viability, and reduce mortality in patients with acute myocardial infarction. In patients with stable coronary disease, collaterals are associated with less angina and ischemia during angioplasty and fewer ischemic events during follow-up. The role of collaterals has not been studied in patients undergoing off-pump or on-pump bypass surgery.
  
  
  RESULTS
  The population consisted of the 281 patients randomized to off-pump or on-pump CABG in the Octopus Study. Collaterals were defined on the baseline angiogram with the Rentrop score and were present in 49% and 51% of the patients in the off-pump and on-pump group, respectively. Perioperative myocardial infarction was defined by a creatine kinase-MB to CK ratio >10% and occurred in 18.2% in the off-pump group and 32.5% in the on-pump group. The unadjusted OR of perioperative myocardial infarction in the presence of collaterals was 0.31 (95% CI 0.17 to 0.84) in the off-pump group and 1.06 (95% CI 0.29 to 3.85) in the on-pump group After adjustment for age, gender, hypertension, hypercholesterolemia, diabetes, multivessel disease, ventricular dysfunction, incomplete revascularization, and ischemic time, the OR was 0.34 (95% CI 0.14 to 0.84) in the off-pump group and 1.28 (95% CI 0.30 to 5.40) in the on-pump group, respectively. Kaplan-Meier estimates of event-free survival at 1 year were 87% in patients with and 69% in those without collaterals after off-pump CABG. These estimates were 66% and 63%, respectively, after on-pump CABG.
  
  
  CONCLUSIONS
  Collaterals protect against perioperative myocardial infarction during off-pump surgery but not during on-pump surgery and are associated with a better 1-year event-free survival.
authors.affiliation: Department of Cardiology, Heart Lung Center Utrecht, Utrecht, The Netherlands.
authors.forename: Hendrik M
authors.initials: HM
authors.lastname: Nathoe
authors.forename: Erik
authors.initials: E
authors.lastname: Buskens
authors.forename: Erik W L
authors.initials: EW
authors.lastname: Jansen
authors.forename: Willem J L
authors.initials: WJ
authors.lastname: Suyker
authors.forename: Pieter R
authors.initials: PR
authors.lastname: Stella
authors.forename: Jaap R
authors.initials: JR
authors.lastname: Lahpor
authors.forename: Wim-Jan
authors.initials: WJ
authors.lastname: van Boven
authors.forename: Diederik
authors.initials: D
authors.lastname: van Dijk
authors.forename: Jan C
authors.initials: JC
authors.lastname: Diephuis
authors.forename: Cornelius
authors.initials: C
authors.lastname: Borst
authors.forename: Karel G M
authors.initials: KG
authors.lastname: Moons
authors.forename: Diederick E
authors.initials: DE
authors.lastname: Grobbee
authors.forename: Peter P T
authors.initials: PP
authors.lastname: de Jaegere
mesh_terms: D000368:Aged; D000787:Angina Pectoris / Q000601:surgery; D003097:Collateral Circulation / Q000502:physiology*; D001026:Coronary Artery Bypass; D047549:Coronary Artery Bypass, Off-Pump; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007431:Intraoperative Complications / Q000517:prevention & control*; D015993:Life Tables; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000517:prevention & control*; D011183:Postoperative Complications / Q000517:prevention & control*; D016032:Randomized Controlled Trials as Topic; D016896:Treatment Outcome