title: Coronary artery spatial distribution of chronic total occlusions: Insights from a large US registry.
abstract: OBJECTIVE
  To assess the spatial distribution of chronic total occlusions (CTOs) within the coronary arteries and describe procedural strategies and outcomes during CTO percutaneous coronary intervention (PCI).
  
  
  BACKGROUND
  Acute occlusions due to plaque rupture tend to cluster within the proximal third of the coronary artery.
  
  
  METHODS
  We examined the clinical and procedural characteristics of 1,348 patients according to lesion location within the coronary tree.
  
  
  RESULTS
  A total of 1,369 lesions in 1,348 patients (mean age 66 ± 10 years, 85% male) were included. CTO PCI of proximal segments (n = 633, 46%) was more common than of mid (n = 557, 41%) and distal segments (n = 179, 13%). Patients undergoing CTO PCI of proximal segments were more likely to be smokers (P < 0.01), have prior coronary artery bypass graft surgery (P = 0.03) and lower ejection fraction (P = 0.04). CTOs occurring in proximal segments had longer length (P <0.01), proximal cap ambiguity (P < 0.01), and moderate/severe calcification (P < 0.01) compared to mid or distally located CTOs. Interventional collaterals were more often present in CTO PCI of proximal segments (64%, 53%, 56%, P < 0.01) consistent with the higher use of retrograde approach (47%, 33%, 37%, P < 0.01) relative to antegrade wire escalation (67%, 82%, 82%, P < 0.01). Procedural complexity was higher in CTO PCI of proximal segments (vs. mid and distal): contrast volume= 275 ml (200-375), 260 ml (200-350), 250 ml (175-350), P = 0.01; fluoroscopy time 53 minutes (32-83), 39 minutes (24-65), 40 minutes (22-72), P < 0.01. However, procedural success (87%, 90%, 85%, P = 0.1), technical success (89%, 91%, 88%, P = 0.24), and complications rates (2.8%, 2.5%, 2.2%, P = 0.88) were not different.
  
  
  CONCLUSIONS
  The most common target vessel location for CTO PCI is the proximal coronary segment. PCI of proximal occlusions is associated with adverse clinical and angiographic characteristics and often requires use of the retrograde approach, but can be accomplished with high procedural and technical success and low complication rates. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Minneapolis VA Medical Center and University of Minnesota, Minneapolis, Minnesota.
authors.forename: Santiago
authors.initials: S
authors.lastname: Garcia
authors.affiliation: Minneapolis VA Medical Center and University of Minnesota, Minneapolis, Minnesota.
authors.forename: M Chadi
authors.initials: MC
authors.lastname: Alraies
authors.affiliation: VA North Texas Health Care System and University of Texas Southwestern Medical Center, Dallas, Texas.
authors.forename: Aris
authors.initials: A
authors.lastname: Karatasakis
authors.affiliation: Minneapolis VA Medical Center and University of Minnesota, Minneapolis, Minnesota.
authors.forename: Demetris
authors.initials: D
authors.lastname: Yannopoulos
authors.affiliation: Columbia University, New York, New York.
authors.forename: Dimitri
authors.initials: D
authors.lastname: Karmpaliotis
authors.affiliation: Henry Ford Health System, Edith and Benson Ford Heart and Vascular Institute, Detroit, Michigan.
authors.forename: Khaldoon
authors.initials: K
authors.lastname: Alaswad
authors.affiliation: Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Farouc A
authors.initials: FA
authors.lastname: Jaffer
authors.affiliation: Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Yeh
authors.affiliation: UC San Diego Medical Center, San Diego, California.
authors.forename: Mitul P
authors.initials: MP
authors.lastname: Patel
authors.affiliation: UC San Diego Medical Center, San Diego, California.
authors.forename: John
authors.initials: J
authors.lastname: Bahadorani
authors.affiliation: VA North Texas Health Care System and University of Texas Southwestern Medical Center, Dallas, Texas.
authors.forename: Judit
authors.initials: J
authors.lastname: Karacsonyi
authors.affiliation: VA North Texas Health Care System and University of Texas Southwestern Medical Center, Dallas, Texas.
authors.forename: Pratik
authors.initials: P
authors.lastname: Kalsaria
authors.affiliation: VA North Texas Health Care System and University of Texas Southwestern Medical Center, Dallas, Texas.
authors.forename: Barbara
authors.initials: B
authors.lastname: Danek
authors.affiliation: VA North Texas Health Care System and University of Texas Southwestern Medical Center, Dallas, Texas.
authors.forename: Subhash
authors.initials: S
authors.lastname: Banerjee
authors.affiliation: VA North Texas Health Care System and University of Texas Southwestern Medical Center, Dallas, Texas.
authors.forename: Emmanouil S
authors.initials: ES
authors.lastname: Brilakis
mesh_terms: D000368:Aged; D002908:Chronic Disease; D003097:Collateral Circulation; D017023:Coronary Angiography; D003326:Coronary Circulation; D054059:Coronary Occlusion / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000628:therapy*; D003331:Coronary Vessels / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D062645:Percutaneous Coronary Intervention / Q000009:adverse effects / Q000379:methods; D058226:Plaque, Atherosclerotic; D011237:Predictive Value of Tests; D012042:Registries; D012307:Risk Factors; D012422:Rupture, Spontaneous; D013997:Time Factors; D016896:Treatment Outcome; D014481:United States
keywords: chronic total occlusion; coronary artery disease; percutaneous coronary intervention