title: Learning curves for transfemoral transcatheter aortic valve replacement in the PARTNER-I trial: Technical performance.
abstract: OBJECTIVE
  To assess technical performance learning curves of teams performing transfemoral transcatheter aortic valve replacement (TF-TAVR).
  
  
  BACKGROUND
  TF-TAVR is a new procedure for treating severe aortic stenosis. The number of cases required for procedural efficiency is unknown.
  
  
  METHODS
  In the PARTNER-I trial, 1,521 patients underwent TF-TAVR from 4/2007-2/2012. Learning curve analysis of technical performance metrics was performed using institution-specific patient sequence number, interval between procedures, and institutional trial entry date. Learning curve characteristics were assessed using semi-parametric and parametric mixed-effects models.
  
  
  RESULTS
  As patient sequence number increased, average procedure time decreased from 154 to 85 minutes (P < 0.0001), and fluoroscopy time from 28 to 20 minutes (P < 0.0001). Procedure time plateaued at an average of 83 minutes (range 52-140). Procedure time plateau was dynamic during the course of the trial, averaging 25 cases (range 21-52) by its end. The later institutions enrolled in the trial, the shorter the initial procedure time. During the trial, percutaneous rather than surgical access increased from 7.9% to 69%.
  
  
  CONCLUSIONS
  Technical performance learning curves exist for TF-TAVR; procedural efficiency increased with experience, with concomitant decreases in radiation and contrast media exposure. The number of cases needed to achieve efficiency decreased progressively, with optimal procedural performance reached after approximately 25 cases for late-entering institutions. Knowledge and experience accumulated by early TF-TAVR institutions were disseminated, shortening the learning curve of late-entering institutions. Technological advances resulting from learning during the trial moved the field from initial conservative surgical cut-down to percutaneous access for most patients. © 2015 Wiley Periodicals, Inc.
authors.affiliation: University of Alabama, Birmingham, Alabama.
authors.forename: Oluseun
authors.initials: O
authors.lastname: Alli
authors.affiliation: Mayo Clinic, Rochester, Minnesota.
authors.forename: Charanjit S
authors.initials: CS
authors.lastname: Rihal
authors.affiliation: Cleveland Clinic, Cleveland, Ohio.
authors.forename: Rakesh M
authors.initials: RM
authors.lastname: Suri
authors.affiliation: Mayo Clinic, Rochester, Minnesota.
authors.forename: Kevin L
authors.initials: KL
authors.lastname: Greason
authors.affiliation: MedStar Washington Hospital Center, Washington, DC.
authors.forename: Ron
authors.initials: R
authors.lastname: Waksman
authors.affiliation: MedStar Washington Hospital Center, Washington, DC.
authors.forename: Sa'ar
authors.initials: S
authors.lastname: Minha
authors.affiliation: MedStar Washington Hospital Center, Washington, DC.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Torguson
authors.affiliation: MedStar Washington Hospital Center, Washington, DC.
authors.forename: Augusto D
authors.initials: AD
authors.lastname: Pichard
authors.affiliation: Baylor Scott & White Health, Plano, Texas.
authors.forename: Michael
authors.initials: M
authors.lastname: Mack
authors.affiliation: Cleveland Clinic, Cleveland, Ohio.|PARTNER Publications Office.
authors.forename: Lars G
authors.initials: LG
authors.lastname: Svensson
authors.affiliation: Cleveland Clinic, Cleveland, Ohio.|PARTNER Publications Office.
authors.forename: Jeevanantham
authors.initials: J
authors.lastname: Rajeswaran
authors.affiliation: Cleveland Clinic, Cleveland, Ohio.
authors.forename: Ashley M
authors.initials: AM
authors.lastname: Lowry
authors.affiliation: Cleveland Clinic, Cleveland, Ohio.
authors.forename: John
authors.initials: J
authors.lastname: Ehrlinger
authors.affiliation: Cleveland Clinic, Cleveland, Ohio.
authors.forename: E Murat
authors.initials: EM
authors.lastname: Tuzcu
authors.affiliation: Emory University School of Medicine, Atlanta, Georgia.
authors.forename: Vinod H
authors.initials: VH
authors.lastname: Thourani
authors.affiliation: Cedars Sinai Medical Center, Los Angeles, California.
authors.forename: Raj
authors.initials: R
authors.lastname: Makkar
authors.affiliation: Cleveland Clinic, Cleveland, Ohio.|PARTNER Publications Office.
authors.forename: Eugene H
authors.initials: EH
authors.lastname: Blackstone
authors.affiliation: PARTNER Publications Office.|Columbia University Medical Center/New York-Presbyterian Hospital, New York, New York.
authors.forename: Martin B
authors.initials: MB
authors.lastname: Leon
authors.affiliation: Mayo Clinic, Rochester, Minnesota.
authors.forename: David
authors.initials: D
authors.lastname: Holmes
mesh_terms: D000369:Aged, 80 and over; D001021:Aortic Valve / Q000601:surgery*; D001024:Aortic Valve Stenosis / Q000601:surgery*; D004503:Education, Medical, Graduate / Q000592:standards*; D005260:Female; D005263:Femoral Artery; D006350:Heart Valve Prosthesis; D006801:Humans; D059032:Learning Curve; D008297:Male; D012720:Severity of Illness Index; D013997:Time Factors; D065467:Transcatheter Aortic Valve Replacement / Q000193:education* / Q000379:methods
keywords: learning curve; procedural efficiency; transfemoral transcatheter aortic valve replacement