title: Impact of Proximal Cap Ambiguity on Outcomes of Chronic Total Occlusion Percutaneous Coronary Intervention: Insights From a Multicenter US Registry.
abstract: OBJECTIVE
  We sought to determine the impact of proximal cap ambiguity on procedural techniques and outcomes for coronary chronic total occlusion (CTO) percutaneous coronary intervention (PCI).
  
  
  METHODS
  We examined the clinical and angiographic characteristics and outcomes of 1021 CTO-PCIs performed between 2012 and 2015 at 11 United States centers.
  
  
  RESULTS
  Proximal cap ambiguity was present in 31% of target lesions and was associated with increased clinical and angiographic complexity (prior coronary artery bypass graft surgery: 43% vs 33%; P=.01; moderate/severe calcification 66% vs 51%; P<.001) and lower technical success (85% vs 93%; P<.001) and procedural success (84% vs 91%; P=.01), but similar incidence of major adverse cardiac events (3.2% vs 2.9%; P=.77). A retrograde approach was more commonly utilized among cases with proximal cap ambiguity (68% vs 33%; P<.001), and was more likely to be the initial (39% vs 13%; P<.001) and successful approach (42% vs 20%; P<.001). Proximal cap ambiguity was associated with increased use of intravascular ultrasound (49% vs 36%; P=.01) and contrast (281 mL vs 250 mL; P<.001), higher air kerma radiation dose (4.0 Gy vs 3.0 Gy; P<.001), and longer procedure time (161 min vs 119 min; P<.001).
  
  
  CONCLUSIONS
  Proximal cap ambiguity is present in one-third of CTO-PCI target lesions and is associated with lower success rates, higher utilization of the retrograde approach, and lower procedural efficiency, but no significant difference in the incidence of major adverse cardiac events.
authors.forename: Aris
authors.initials: A
authors.lastname: Karatasakis
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Danek
authors.forename: Dimitri
authors.initials: D
authors.lastname: Karmpaliotis
authors.forename: Khaldoon
authors.initials: K
authors.lastname: Alaswad
authors.forename: Farouc A
authors.initials: FA
authors.lastname: Jaffer
authors.forename: Robert W
authors.initials: RW
authors.lastname: Yeh
authors.forename: Mitul P
authors.initials: MP
authors.lastname: Patel
authors.forename: John N
authors.initials: JN
authors.lastname: Bahadorani
authors.forename: R Michael
authors.initials: RM
authors.lastname: Wyman
authors.forename: William L
authors.initials: WL
authors.lastname: Lombardi
authors.forename: J Aaron
authors.initials: JA
authors.lastname: Grantham
authors.forename: David E
authors.initials: DE
authors.lastname: Kandzari
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Lembo
authors.forename: Anthony H
authors.initials: AH
authors.lastname: Doing
authors.forename: Jeffrey W
authors.initials: JW
authors.lastname: Moses
authors.forename: Ajay J
authors.initials: AJ
authors.lastname: Kirtane
authors.forename: Santiago
authors.initials: S
authors.lastname: Garcia
authors.forename: Manish A
authors.initials: MA
authors.lastname: Parikh
authors.forename: Ziad A
authors.initials: ZA
authors.lastname: Ali
authors.forename: Judit
authors.initials: J
authors.lastname: Karacsonyi
authors.forename: Sanjog
authors.initials: S
authors.lastname: Kalra
authors.forename: Bavana V
authors.initials: BV
authors.lastname: Rangan
authors.forename: Pratik
authors.initials: P
authors.lastname: Kalsaria
authors.forename: Craig A
authors.initials: CA
authors.lastname: Thompson
authors.forename: Subhash
authors.initials: S
authors.lastname: Banerjee
authors.affiliation: Dallas VA Medical Center (111A), 4500 South Lancaster Road, Dallas, TX 75216 USA. esbrilakis@gmail.com.
authors.forename: Emmanouil S
authors.initials: ES
authors.lastname: Brilakis
mesh_terms: D000368:Aged; D002908:Chronic Disease; D017023:Coronary Angiography / Q000379:methods / Q000706:statistics & numerical data; D054059:Coronary Occlusion / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology / Q000601:surgery; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010043:Outcome and Process Assessment, Health Care; D062645:Percutaneous Coronary Intervention / Q000009:adverse effects / Q000379:methods; D011183:Postoperative Complications / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology; D012042:Registries; D012307:Risk Factors; D012720:Severity of Illness Index; D018084:Ultrasonography, Interventional / Q000379:methods / Q000706:statistics & numerical data; D014481:United States / Q000453:epidemiology