title: Predictive factors and long-term clinical consequences of persistent left bundle branch block following transcatheter aortic valve implantation with a balloon-expandable valve.
abstract: OBJECTIVE
  This study evaluated the predictive factors and prognostic value of new-onset persistent left bundle branch block (LBBB) in patients undergoing transcatheter aortic valve implantation (TAVI) with a balloon-expandable valve.
  
  
  BACKGROUND
  The predictors of persistent (vs. transient or absent) LBBB after TAVI with a balloon-expandable valve and its clinical consequences are unknown.
  
  
  METHODS
  A total of 202 consecutive patients with no baseline ventricular conduction disturbances or previous permanent pacemaker implantation (PPI) who underwent TAVI with a balloon-expandable valve were included. Patients were on continuous electrocardiographic (ECG) monitoring during hospitalization and 12-lead ECG was performed daily until hospital discharge. No patient was lost at a median follow-up of 12 (range: 6 to 24) months, and ECG tracing was available in 97% of patients. The criteria for PPI were limited to the occurrence of high-degree atrioventricular block (AVB) or severe symptomatic bradycardia.
  
  
  RESULTS
  New-onset LBBB was observed in 61 patients (30.2%) after TAVI, and had resolved in 37.7% and 57.3% at hospital discharge and 6- to 12-month follow-up, respectively. Baseline QRS duration (p = 0.037) and ventricular depth of the prosthesis (p = 0.017) were independent predictors of persistent LBBB. Persistent LBBB at hospital discharge was associated with a decrease in left ventricular ejection fraction (p = 0.001) and poorer functional status (p = 0.034) at 1-year follow-up. Patients with persistent LBBB and no PPI at hospital discharge had a higher incidence of syncope (16.0% vs. 0.7%; p = 0.001) and complete AVB requiring PPI (20.0% vs. 0.7%; p < 0.001), but not of global mortality or cardiac mortality during the follow-up period (all, p > 0.20). New-onset LBBB was the only factor associated with PPI following TAVI (p < 0.001).
  
  
  CONCLUSIONS
  Up to 30% of patients with no prior conduction disturbances developed new LBBB following TAVI with a balloon-expandable valve, although it was transient in more than one third. Longer baseline QRS duration and a more ventricular positioning of the prosthesis were associated with a higher rate of persistent LBBB, which in turn determined higher risks for complete AVB and PPI, but not mortality, at 1-year follow-up.
authors.affiliation: Quebec Heart & Lung Institute, Laval University, Quebec City, Quebec, Canada.
authors.forename: Marina
authors.initials: M
authors.lastname: Urena
authors.forename: Michael
authors.initials: M
authors.lastname: Mok
authors.forename: Vicenç
authors.initials: V
authors.lastname: Serra
authors.forename: Eric
authors.initials: E
authors.lastname: Dumont
authors.forename: Luis
authors.initials: L
authors.lastname: Nombela-Franco
authors.forename: Robert
authors.initials: R
authors.lastname: DeLarochellière
authors.forename: Daniel
authors.initials: D
authors.lastname: Doyle
authors.forename: Albert
authors.initials: A
authors.lastname: Igual
authors.forename: Eric
authors.initials: E
authors.lastname: Larose
authors.forename: Ignacio
authors.initials: I
authors.lastname: Amat-Santos
authors.forename: Mélanie
authors.initials: M
authors.lastname: Côté
authors.forename: Hug
authors.initials: H
authors.lastname: Cuéllar
authors.forename: Philippe
authors.initials: P
authors.lastname: Pibarot
authors.forename: Peter
authors.initials: P
authors.lastname: de Jaegere
authors.forename: François
authors.initials: F
authors.lastname: Philippon
authors.forename: Bruno
authors.initials: B
authors.lastname: Garcia del Blanco
authors.forename: Josep
authors.initials: J
authors.lastname: Rodés-Cabau
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000800:Angioplasty, Balloon / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D001021:Aortic Valve / Q000473:pathology*; D001024:Aortic Valve Stenosis / Q000473:pathology / Q000628:therapy*; D054537:Atrioventricular Block; D001919:Bradycardia / Q000175:diagnosis; D002037:Bundle-Branch Block / Q000175:diagnosis* / Q000209:etiology / Q000628:therapy*; D004562:Electrocardiography / Q000379:methods; D004594:Electrophysiology / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000379:methods; D006801:Humans; D008297:Male; D011379:Prognosis; D013997:Time Factors; D016896:Treatment Outcome; D016277:Ventricular Function, Left