title: Effectiveness of recanalization of chronic total occlusions: a systematic review and meta-analysis.
abstract: BACKGROUND
  Chronic total occlusion (CTO) recanalizations remain extremely challenging procedures. With improvements in technology and techniques, success rates for recanalization of CTO continue to improve. However, the clinical benefits of this practice remain unclear. The aim of the study was to determine the effectiveness of CTO recanalization on clinical outcomes.
  
  
  METHODS
  We performed a systematic review and meta-analysis of published studies comparing CTO recanalization to medical management. Data were extracted in duplicate and analyzed by a random effects model.
  
  
  RESULTS
  We did not identify any randomized controlled trials or observational studies comparing CTO recanalization to a planned medical management. We did identify 13 observational studies comparing outcomes after successful vs failed CTO recanalization attempt. These studies encompassed 7,288 patients observed over a weighted average follow-up of 6 years. There were 721 (14.3%) deaths of 5,056 patients after successful CTO recanalization compared to 390 deaths (17.5%) of 2,232 patients after failed CTO recanalization (odds ratio [OR] 0.56, 95% CI 0.43-0.72). Successful recanalization was associated with a significant reduction in subsequent coronary artery bypass graft surgery (CABG) (OR 0.22, 95% CI 0.17-0.27) but not in myocardial infarction (OR 0.74, 95% CI 0.44-1.25) or major adverse cardiac events (OR 0.81, 95% CI 0.55-1.21). In the 6 studies that reported angina status, successful recanalization was associated with a significant reduction in residual/recurrent angina (OR 0.45, 95% CI 0.30-0.67).
  
  
  CONCLUSIONS
  In highly selected patients considered for CTO recanalization, successful attempts appear to be associated with an improvement in mortality and with a reduction for the need for CABG as compared to failed recanalization. However, given the observational nature of the reviewed evidence, randomized clinical trials are needed to confirm these findings.
authors.affiliation: Division of Cardiology, Sir Mortimer B. Davis Jewish General Hospital, McGill University, Montreal, Quebec, Canada.
authors.forename: Dominique
authors.initials: D
authors.lastname: Joyal
authors.forename: Jonathan
authors.initials: J
authors.lastname: Afilalo
authors.forename: Stéphane
authors.initials: S
authors.lastname: Rinfret
mesh_terms: D002908:Chronic Disease; D023921:Coronary Stenosis / Q000601:surgery*; D006801:Humans; D009204:Myocardial Revascularization / Q000379:methods*; D015203:Reproducibility of Results; D016896:Treatment Outcome