title: Frequency and prognosis of new bundle branch block induced by surgical aortic valve replacement.
abstract: OBJECTIVE
  Recently, transcatheter aortic valve implantation has been introduced, but one of its complications is left bundle branch block (LBBB), a conduction disturbance that has been associated with increased mortality. We investigated the incidence and fate of both right bundle branch block (RBBB) and LBBB after aortic valve replacement (AVR) using a retrospective analysis. We also studied the predictive value of both disorders for all-cause mortality.
  
  
  METHODS
  All patients who underwent AVR, with or without concomitant coronary artery bypass grafting surgery, between 2002 and 2010 in our centre were included. All-cause mortality was compared between patients who did and those who did not develop persistent new bundle branch block (BBB) within 7 days postoperatively. Patients were not eligible if one of their electrocardiogram (ECG) recordings prior to AVR showed a BBB or pacemaker activity. A postoperative period of 3-12 months was used to collect follow-up ECGs.
  
  
  RESULTS
  Of the 2279 AVR patients, 2033 patients were eligible for analysis. After excluding patients lacking baseline or follow-up ECG (n = 269), 1764 patients remained for analysis. Early LBBB and RBBB occurred in 71 (4.0%) and 92 (5.2%) patients, respectively. At follow-up, LBBB was persistent in 29 patients (1.6%) and RBBB in 74 patients (4.2%). During a median follow-up of 4.5 (2.4-6.5) years, the mortality rate was 16.3% (n = 271) in patients without BBB, 24.1% (n = 7) in patients with persistent LBBB and 18.9% (n = 14) in patients with persistent RBBB (log-rank P = 0.49). Though, in univariate analysis, the hazard ratio for mortality was 1.54 and 1.10 for LBBB and RBBB, respectively, the small numbers precluded identifying AVR-induced LBBB and RBBB as a predictor of mortality.
  
  
  CONCLUSIONS
  In the current practice of AVR, persistent postoperative LBBB and RBBB occur infrequently (∼ 5% of cases), a percentage less than half of that in current transcatheter aortic valve implantation procedures. Given the adverse effects of LBBB, the lower prevalence of procedure-induced LBBB in AVR should be taken into account while deciding which valve replacement procedure is chosen for a patient.
authors.affiliation: Department of Cardiothoracic Surgery, Maastricht University Medical Center, Maastricht, Netherlands thomas.poels@mumc.nl.
authors.forename: Thomas T
authors.initials: TT
authors.lastname: Poels
authors.affiliation: Department of Cardiothoracic Surgery, Catharina Hospital, Eindhoven, Netherlands Cardiovascular Research Institute Maastricht, Maastricht, Netherlands.
authors.forename: Patrick
authors.initials: P
authors.lastname: Houthuizen
authors.affiliation: Department of Cardiothoracic Surgery, Catharina Hospital, Eindhoven, Netherlands.
authors.forename: Leen A F M
authors.initials: LA
authors.lastname: Van Garsse
authors.affiliation: Department of Cardiothoracic Surgery, Catharina Hospital, Eindhoven, Netherlands.
authors.forename: Mohammed A
authors.initials: MA
authors.lastname: Soliman Hamad
authors.affiliation: Department of Cardiothoracic Surgery, Maastricht University Medical Center, Maastricht, Netherlands.
authors.forename: Jos G
authors.initials: JG
authors.lastname: Maessen
authors.affiliation: Cardiovascular Research Institute Maastricht, Maastricht, Netherlands.
authors.forename: Frits W
authors.initials: FW
authors.lastname: Prinzen
authors.affiliation: Department of Cardiothoracic Surgery, Catharina Hospital, Eindhoven, Netherlands.
authors.forename: Albert H M
authors.initials: AH
authors.lastname: Van Straten
mesh_terms: D000368:Aged; D001021:Aortic Valve / Q000601:surgery*; D001145:Arrhythmias, Cardiac; D002037:Bundle-Branch Block / Q000453:epidemiology / Q000209:etiology* / Q000401:mortality*; D005260:Female; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects* / Q000401:mortality*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors
keywords: Aortic valve; Arrhythmia (any); Replacement; Statistics; Survival analysis