title: Trends in the occurrence of new conduction abnormalities after transcatheter aortic valve implantation.
abstract: OBJECTIVE
  The aim of the study was to investigate trends over time in the occurrence of left bundle branch block (LBBB) and permanent pacemaker implantation (PPI) after transcatheter aortic valve implantation (TAVI) with the Medtronic CoreValve System (MCS) and Edwards SAPIEN Valve (ESV).
  
  
  BACKGROUND
  TAVI-induced conduction abnormalities (TAVI-CAs) such as LBBB and the need for PPI are frequent postoperative complication. New techniques, procedural refinements, and increased awareness are focused on the reduction of these abnormalities.
  
  
  METHODS
  Electrocardiograms of 549 patients without preprocedural LBBB and/or pacemaker were assessed to determine the frequency and nature of TAVI-CAs. To study the effect of experience, patients were subdivided per center into tertiles based on the number of procedures. Univariate and multivariate logistic regression was used to study predictors of TAVI-induced LBBB (TAVI-LBBB) and PPI.
  
  
  RESULTS
  TAVI-LBBB occurred in 185 patients (33.7%) and significantly decreased over time, from 42.6% to 27.3% (P=0.006). This effect was only significant after implantation of the MCS (59.6% vs. 46.5% vs. 31.1%, P=0.001, ESV: 22.6% vs. 13.1% vs. 24.8%, P=0.11). Between tertiles there was no difference in the frequency of PPI after TAVI (n=73, 13.1% vs. 14.8% vs. 12%, P=0.74). Multivariate analysis revealed that, independent from valve type, depth of implantation was the only significant predictor of TAVI-LBBB (OR [95% C.I.]: 1.16 [1.10-1.24], P<0.001). In case of PPI pre-existing RBBB (OR [95% C.I.]: 7.22 [3.28-15.88], P<0.001) was the only significant predictor.
  
  
  CONCLUSIONS
  Over time the frequency of LBBB after TAVI decreased significantly, especially in patients undergoing TAVI with the MCS. Experience and the subsequent reduction in depth of implantation seem responsible for this reduction. Contrary to TAVI-LBBB, the incidence of PPI remained unchanged over time and was not affected by experience. Although experience has led to a decrease in new CAs after TAVI, elucidation of pathophysiologic mechanisms underlying these CAs and subsequent changes in patient stratification, valve design and the procedure are needed to further reduce this complication.
authors.affiliation: Erasmus Medical Center, Rotterdam, The Netherlands.
authors.forename: Robert M A
authors.initials: RM
authors.lastname: van der Boon
authors.forename: Patrick
authors.initials: P
authors.lastname: Houthuizen
authors.forename: Marina
authors.initials: M
authors.lastname: Urena
authors.forename: Thomas T
authors.initials: TT
authors.lastname: Poels
authors.forename: Nicolas M
authors.initials: NM
authors.lastname: van Mieghem
authors.forename: Guus R G
authors.initials: GR
authors.lastname: Brueren
authors.forename: Sibel
authors.initials: S
authors.lastname: Altintas
authors.forename: Rutger Jan
authors.initials: RJ
authors.lastname: Nuis
authors.forename: Patrick W
authors.initials: PW
authors.lastname: Serruys
authors.forename: Leen A F M
authors.initials: LA
authors.lastname: van Garsse
authors.forename: Ron T
authors.initials: RT
authors.lastname: van Domburg
authors.forename: Joseph Rodés
authors.initials: JR
authors.lastname: Cabau
authors.forename: Peter P T
authors.initials: PP
authors.lastname: de Jaegere
authors.forename: Frits W
authors.initials: FW
authors.lastname: Prinzen
mesh_terms: D000369:Aged, 80 and over; D001024:Aortic Valve Stenosis / Q000601:surgery; D002037:Bundle-Branch Block / Q000453:epidemiology* / Q000209:etiology / Q000628:therapy; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006350:Heart Valve Prosthesis / Q000009:adverse effects; D006801:Humans; D015994:Incidence; D008297:Male; D009426:Netherlands / Q000453:epidemiology; D010138:Pacemaker, Artificial; D011183:Postoperative Complications; D011792:Quebec / Q000453:epidemiology; D012189:Retrospective Studies; D065467:Transcatheter Aortic Valve Replacement / Q000009:adverse effects*
keywords: left bundle branch block; permanent pacemaker implantation; transcatheter aortic valve implantation