title: Influence of angiographic collateral circulation on myocardial perfusion in patients with chronic total occlusion of a single coronary artery and no prior myocardial infarction.
abstract: The functional role of various angiographic grades for coronary collaterals remains controversial. The aim of this study was to assess the influence of the Rentrop angiographic grading of coronary collaterals on myocardial perfusion in patients with single-vessel chronic total occlusion (CTO) and no prior myocardial infarction (MI).
  
  
  METHODS
  The study included 56 patients with single-vessel CTO and no prior MI who underwent rest-stress myocardial perfusion SPECT and coronary angiography within 6 mo. All patients had angiographic evidence of coronary collaterals. Patients were divided according to the Rentrop classification: Group I had grade 1 or 2 (n = 25) and group II had grade 3 collaterals (n = 31).
  
  
  RESULTS
  Group I had a higher frequency of resting regional wall motion abnormalities on left ventriculography (52.6% vs. 19.2% [P = 0.019]). The mean perfusion scores of the overall population showed severe and extensive stress perfusion defects (summed stress score of 14.1 +/- 7.1 and summed difference score of 12.9 +/- 6.9) but minimal resting perfusion defects (summed rest score of 1.0 +/- 2.7). No perfusion scores differed between the 2 groups. The perfusion findings suggested that chronic stunning rather than hibernation is the principal cause of regional wall motion abnormalities in these patients.
  
  
  CONCLUSIONS
  In the setting of single-vessel CTO and no prior MI, coronary collaterals appear to protect against resting perfusion defects. Excellent angiographic collaterals may prevent resting regional wall motion abnormalities but do not appear to protect against stress-induced perfusion defects.
authors.affiliation: Department of Imaging, Cedars-Sinai Medical Center, Los Angeles, California 90048, USA.
authors.forename: Fatma
authors.initials: F
authors.lastname: Aboul-Enein
authors.forename: Saibal
authors.initials: S
authors.lastname: Kar
authors.forename: Sean W
authors.initials: SW
authors.lastname: Hayes
authors.forename: Maria
authors.initials: M
authors.lastname: Sciammarella
authors.forename: Aiden
authors.initials: A
authors.lastname: Abidov
authors.forename: Raj
authors.initials: R
authors.lastname: Makkar
authors.forename: John D
authors.initials: JD
authors.lastname: Friedman
authors.forename: Neal
authors.initials: N
authors.lastname: Eigler
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Berman
mesh_terms: D000368:Aged; D002908:Chronic Disease; D003097:Collateral Circulation; D017023:Coronary Angiography; D023921:Coronary Stenosis / Q000150:complications / Q000000981:diagnostic imaging*; D003331:Coronary Vessels / Q000000981:diagnostic imaging*; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D009203:Myocardial Infarction / Q000000981:diagnostic imaging; D011877:Radionuclide Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000209:etiology