title: Impact of Chronic Total Occlusions on Revascularization Scores and Outcome Prediction.
abstract: OBJECTIVE
  To evaluate the contribution of chronic total occlusion (CTO)-related SYNTAX score (SS) to the overall SS for patients with CTO and compare the traditional SS to a simplified variant. The SS algorithm assigns CTO lesions a greater weight (5× points) than non-CTO lesions (50% to <100% diameter stenosis; 2× points).
  
  
  METHODS
  We calculated the SS and the simplified SS (2× points also to CTO lesions) for 4356 patients from the angiographic substudy of the Acute Catheterization and Urgent Intervention Triage StrategY (ACUITY) trial. We compared the association between SS and 1-year mortality and major adverse cardiac events for patients with and without a CTO. We also compared the simplified SS with the traditional SS.
  
  
  RESULTS
  The median SS was 20 (interquartile range, 13-27.5) for patients with a CTO and 8 (interquartile range, 2-16) for patients without a CTO. For patients with a CTO, the CTO lesion(s) contributed 67 ± 26% of the total SS. The simplified SS reclassified 187/603 (31.0%) of patients with a SS >22 to a SS ≤22. The traditional SS did not improve discrimination indices for predicting outcomes compared with the simplified SS.
  
  
  CONCLUSIONS
  CTO lesions contribute considerably to the total SS in patients with a CTO. A simplified SS that does not differentiate between CTO and non-CTO lesions appeared equivalent to the traditional SS for risk prediction, but reclassified a substantial proportion of patients to a SS ≤22 and may impact choice of revascularization strategy for patients with complex coronary artery disease involving a CTO lesion.
authors.forename: Björn
authors.initials: B
authors.lastname: Redfors
authors.forename: Tullio
authors.initials: T
authors.lastname: Palmerini
authors.forename: Adriano
authors.initials: A
authors.lastname: Caixeta
authors.forename: Girma Minalu
authors.initials: GM
authors.lastname: Ayele
authors.forename: Dominic P
authors.initials: DP
authors.lastname: Francese
authors.forename: Roxana
authors.initials: R
authors.lastname: Mehran
authors.forename: Emmanouil S
authors.initials: ES
authors.lastname: Brilakis
authors.forename: Ajay J
authors.initials: AJ
authors.lastname: Kirtane
authors.forename: Dimitri
authors.initials: D
authors.lastname: Karmpaliotis
authors.forename: Gregg W
authors.initials: GW
authors.lastname: Stone
authors.affiliation: Cardiovascular Research Foundation, 1700 Broadway, 9th Floor, New York, NY 10019 USA. pgenereux@crf.org.
authors.forename: Philippe
authors.initials: P
authors.lastname: Généreux
mesh_terms: D002908:Chronic Disease; D017023:Coronary Angiography; D054059:Coronary Occlusion / Q000150:complications / Q000175:diagnosis* / Q000601:surgery; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009204:Myocardial Revascularization; D000072658:Non-ST Elevated Myocardial Infarction / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D011379:Prognosis; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology