title: Influence on collateral flow of recanalising chronic total coronary occlusions: a case-control study.
abstract: OBJECTIVE
  To assess the effect of recanalisation on collateral flow in a case-control study in patients with and without chronic total coronary occlusions.
  
  
  METHODS
  In 54 patients undergoing percutaneous transluminal coronary angioplasty (PTCA) (mean (SD) age 61 (6) years), coronary collateral flow was measured by intracoronary pressure or Doppler guide wires at the end of repeated balloon occlusions. Coronary collateral flow index (collateral flow relative to normal antegrade flow) during the first two balloon inflations in 27 patients with a chronic total occlusion (occlusion group) was compared with that of 27 patients matched for age, sex, and collateral flow index at the first occlusion and with a coronary artery diameter stenosis </= 80% (stenosis group).
  
  
  RESULTS
  Following revascularisation, collateral flow index decreased in 17 of the patients in the occlusion group (63%) and in eight of the patients in the stenosis group (30%) (p = 0.03 between groups). The overall change of collateral flow index between the first and the second balloon occlusion was -0.04 (0.01) in the occlusion group (p = 0.07 for paired comparison; from 0.29 (0.17) to 0.25 (0.14)), and +0.02 (0.06) in the stenosis group (p = 0.06 for paired comparison; from 0.27 (0.13) to 0.30 (0.15)). The trend to collateral enhancement in the stenosis group differed significantly from the occlusion group (p = 0.01).
  
  
  CONCLUSIONS
  While repeated coronary balloon occlusions induce collateral recruitment in the majority of patients with moderate stenoses, recanalisation of chronic total coronary occlusions is more often associated with collateral flow reduction. A later decrease in collateral flow by involution of collateral channels cannot be excluded by this study but has not been reported so far.
authors.affiliation: Cardiology, Swiss Cardiovascular Centre Bern, University Hospital, CH-3010 Bern, Switzerland.
authors.forename: T
authors.initials: T
authors.lastname: Pohl
authors.forename: P
authors.initials: P
authors.lastname: Hochstrasser
authors.forename: M
authors.initials: M
authors.lastname: Billinger
authors.forename: M
authors.initials: M
authors.lastname: Fleisch
authors.forename: B
authors.initials: B
authors.lastname: Meier
authors.forename: C
authors.initials: C
authors.lastname: Seiler
mesh_terms: D015906:Angioplasty, Balloon, Coronary / Q000379:methods*; D001783:Blood Flow Velocity / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology; D016022:Case-Control Studies; D003326:Coronary Circulation / Q000502:physiology; D003327:Coronary Disease / Q000503:physiopathology / Q000628:therapy*; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009204:Myocardial Revascularization / Q000379:methods*; D011446:Prospective Studies; D012008:Recurrence