title: Subintimal guidewire tracking during successful percutaneous therapy for chronic coronary total occlusions: insights from an intravascular ultrasound analysis.
abstract: OBJECTIVE
  We sought to determine the frequency of subintimal guidewire tracking during successful percutaneous coronary intervention (PCI) for chronic coronary total occlusions (CTOs) and to better understand the procedural implications of this event.
  
  
  BACKGROUND
  Successful PCI for chronic CTO is associated with improved outcomes in patients with ischemia. While subintimal guidewire tracking resulting in failure to cross is recognized as the major mode of failure for CTO PCI, the implications of subintimal guidewire tracking during successful CTO PCI are unknown.
  
  
  METHODS
  Between March 2007 and October 2007, 26 consecutive patients, each with one de-novo CTO lesion successfully crossed with a guidewire were included in the analysis. Intravascular ultrasound (IVUS) was performed in each CTO vessel after guidewire crossing. Cases were classified as having definite subintimal wire tracking or no clear evidence of subintimal wire tracking based on analysis of IVUS images.
  
  
  RESULTS
  Subintimal wire tracking occurred in 45% of cases. In cases where subintimal wire tracking was present, a previous attempt at CTO PCI was more common (42% vs. 7%, P ≤ 0.05). Subintimal wire tracking was also associated with significantly longer final mean stent length (71 vs. 50 mm), procedure time (122 vs. 69 min), fluoroscopy time (47 vs. 22 min), and contrast dose (300 vs. 199 mL, P ≤ 0.05 for all). There was one perforation in the subintimal group which was successfully treated with stent placement.
  
  
  CONCLUSIONS
  Subintimal wire tracking occurs frequently during successful PCI for CTO and is associated with increased lesion and procedural complexity.
authors.affiliation: Cleveland Clinic, Cleveland, Ohio 44195, USA.
authors.forename: Kamran I
authors.initials: KI
authors.lastname: Muhammad
authors.forename: William L
authors.initials: WL
authors.lastname: Lombardi
authors.forename: Ryan
authors.initials: R
authors.lastname: Christofferson
authors.forename: Patrick L
authors.initials: PL
authors.lastname: Whitlow
mesh_terms: D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D057785:Catheters; D002908:Chronic Disease; D054059:Coronary Occlusion / Q000000981:diagnostic imaging* / Q000628:therapy*; D003331:Coronary Vessels / Q000293:injuries; D004867:Equipment Design; D005260:Female; D006335:Heart Injuries / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009820:Ohio; D011474:Prosthesis Design; D015607:Stents; D013997:Time Factors; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional