title: Comparison of procedural complications and in-hospital clinical outcomes between patients with successful and failed percutaneous intervention of coronary chronic total occlusions: a meta-analysis of observational studies.
abstract: BACKGROUND
  Multiple attempts to pass guidewires and balloons across totally occluded segments may result in significant mechanical trauma and higher rates of coronary complications in patients undergoing PCI (percutaneous coronary intervention) for CTOs (chronic total occlusion). It is unknown whether these procedural complications affect short-term survival and in-hospital clinical outcomes after the PCI. The goal of this analysis was to clarify this issue by comparing the rates of adverse in-hospital clinical outcomes between successful and failed CTO-PCI groups.
  
  
  METHODS
  We performed a meta-analysis of 25 studies (16,490 patients) to determine the rates of in-hospital death, myocardial infarction (MI), major adverse cardiovascular events (MACE), and urgent CABG (coronary artery bypass grafting) for the successful and failed CTO-PCI groups.
  
  
  RESULTS
  Compared to successful CTO PCI, failed CTO PCI procedures were associated with higher in-hospital mortality (1.44% versus 0.5%) [relative risk (RR) of 2.88, 95% confidence interval [CI] (1.96-4.24), P<0.001], a higher risk of in-hospital MACE (8.88% versus 3.75%) [RR of 2.25, CI (1.69-2.98), P<0.001], slightly higher risk of in-hospital MI (3.17% versus 2.4%) [RR of 1.35, CI (1.03-1.78), P=0.03] and increased need for urgent CABG (4.0% versus 0.5%) [RR of 6.67, CI (4.26-10.43), P<0.001]. Furthermore, higher rates of coronary perforations [RR of 5.0, CI (3.93-6.59), P<0.001] and cardiac tamponade [RR of 5.0, CI (1.97-12.69), P<0.001] were observed in the unsuccessful PCI arm.
  
  
  CONCLUSIONS
  As compared to successful interventions, failed PCI attempts for CTOs appear to be associated with higher risk of adverse short-term clinical outcomes.
authors.affiliation: Department of Medicine, Southern Arizona VA Health Care System, Tucson, Arizona; Department of Medicine, University of Arizona, Tucson, Arizona.
authors.forename: Muhammad F
authors.initials: MF
authors.lastname: Khan
authors.forename: Emmanouil S
authors.initials: ES
authors.lastname: Brilakis
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Wendel
authors.forename: Hoang
authors.initials: H
authors.lastname: Thai
mesh_terms: D002908:Chronic Disease; D054059:Coronary Occlusion / Q000601:surgery*; D006801:Humans; D064887:Observational Studies as Topic; D062645:Percutaneous Coronary Intervention; D011183:Postoperative Complications; D017211:Treatment Failure
keywords: chronic total occlusions; meta-analysis; percutaneous coronary intervention; peri-procedural complications; short-term outcomes