title: The impact of trans-catheter aortic valve replacement induced left-bundle branch block on cardiac reverse remodeling.
abstract: BACKGROUND
  Left bundle branch block (LBBB) is common following trans-catheter aortic valve replacement (TAVR) and has been linked to increased mortality, although whether this is related to less favourable cardiac reverse remodeling is unclear. The aim of the study was to investigate the impact of TAVR induced LBBB on cardiac reverse remodeling.
  
  
  METHODS
  48 patients undergoing TAVR for severe aortic stenosis were evaluated. 24 patients with new LBBB (LBBB-T) following TAVR were matched with 24 patients with a narrow post-procedure QRS (nQRS). Patients underwent cardiovascular magnetic resonance (CMR) prior to and 6 m post-TAVR. Measured cardiac reverse remodeling parameters included left ventricular (LV) size, ejection fraction (LVEF) and global longitudinal strain (GLS). Inter- and intra-ventricular dyssynchrony were determined using time to peak radial strain derived from CMR Feature Tracking.
  
  
  RESULTS
  In the LBBB-T group there was an increase in QRS duration from 96 ± 14 to 151 ± 12 ms (P < 0.001) leading to inter- and intra-ventricular dyssynchrony (inter: LBBB-T 130 ± 73 vs nQRS 23 ± 86 ms, p < 0.001; intra: LBBB-T 118 ± 103 vs. nQRS 13 ± 106 ms, p = 0.001). Change in indexed LV end-systolic volume (LVESVi), LVEF and GLS was significantly different between the two groups (LVESVi: nQRS -7.9 ± 14.0 vs. LBBB-T -0.6 ± 10.2 ml/m2, p = 0.02, LVEF: nQRS +4.6 ± 7.8 vs LBBB-T -2.1 ± 6.9%, p = 0.002; GLS: nQRS -2.1 ± 3.6 vs. LBBB-T +0.2 ± 3.2%, p = 0.024). There was a significant correlation between change in QRS and change in LVEF (r = -0.434, p = 0.002) and between change in QRS and change in GLS (r = 0.462, p = 0.001). Post-procedure QRS duration was an independent predictor of change in LVEF and GLS at 6 months.
  
  
  CONCLUSIONS
  TAVR-induced LBBB is associated with less favourable cardiac reverse remodeling at medium term follow up. In view of this, every effort should be made to prevent TAVR-induced LBBB, especially as TAVR is now being extended to a younger, lower risk population.
authors.affiliation: Multidisciplinary Cardiovascular Research Centre (MCRC) & Leeds Institute of Cardiovascular and Metabolic Medicine (LICAMM), University of Leeds, Clarendon Way, Leeds, LS2 9JT, UK.
authors.forename: Laura E
authors.initials: LE
authors.lastname: Dobson
authors.affiliation: Multidisciplinary Cardiovascular Research Centre (MCRC) & Leeds Institute of Cardiovascular and Metabolic Medicine (LICAMM), University of Leeds, Clarendon Way, Leeds, LS2 9JT, UK.
authors.forename: Tarique A
authors.initials: TA
authors.lastname: Musa
authors.affiliation: Multidisciplinary Cardiovascular Research Centre (MCRC) & Leeds Institute of Cardiovascular and Metabolic Medicine (LICAMM), University of Leeds, Clarendon Way, Leeds, LS2 9JT, UK.
authors.forename: Akhlaque
authors.initials: A
authors.lastname: Uddin
authors.affiliation: Multidisciplinary Cardiovascular Research Centre (MCRC) & Leeds Institute of Cardiovascular and Metabolic Medicine (LICAMM), University of Leeds, Clarendon Way, Leeds, LS2 9JT, UK.
authors.forename: Timothy A
authors.initials: TA
authors.lastname: Fairbairn
authors.affiliation: Multidisciplinary Cardiovascular Research Centre (MCRC) & Leeds Institute of Cardiovascular and Metabolic Medicine (LICAMM), University of Leeds, Clarendon Way, Leeds, LS2 9JT, UK.
authors.forename: Owen J
authors.initials: OJ
authors.lastname: Bebb
authors.affiliation: Multidisciplinary Cardiovascular Research Centre (MCRC) & Leeds Institute of Cardiovascular and Metabolic Medicine (LICAMM), University of Leeds, Clarendon Way, Leeds, LS2 9JT, UK.
authors.forename: Peter P
authors.initials: PP
authors.lastname: Swoboda
authors.affiliation: Multidisciplinary Cardiovascular Research Centre (MCRC) & Leeds Institute of Cardiovascular and Metabolic Medicine (LICAMM), University of Leeds, Clarendon Way, Leeds, LS2 9JT, UK.
authors.forename: Philip
authors.initials: P
authors.lastname: Haaf
authors.affiliation: Multidisciplinary Cardiovascular Research Centre (MCRC) & Leeds Institute of Cardiovascular and Metabolic Medicine (LICAMM), University of Leeds, Clarendon Way, Leeds, LS2 9JT, UK.
authors.forename: James
authors.initials: J
authors.lastname: Foley
authors.affiliation: Multidisciplinary Cardiovascular Research Centre (MCRC) & Leeds Institute of Cardiovascular and Metabolic Medicine (LICAMM), University of Leeds, Clarendon Way, Leeds, LS2 9JT, UK.
authors.forename: Pankaj
authors.initials: P
authors.lastname: Garg
authors.affiliation: Multidisciplinary Cardiovascular Research Centre (MCRC) & Leeds Institute of Cardiovascular and Metabolic Medicine (LICAMM), University of Leeds, Clarendon Way, Leeds, LS2 9JT, UK.
authors.forename: Graham J
authors.initials: GJ
authors.lastname: Fent
authors.affiliation: Department of Cardiology, Leeds Teaching Hospitals NHS Trust, Leeds, LS1 3EX, UK.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Malkin
authors.affiliation: Department of Cardiology, Leeds Teaching Hospitals NHS Trust, Leeds, LS1 3EX, UK.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Blackman
authors.affiliation: Multidisciplinary Cardiovascular Research Centre (MCRC) & Leeds Institute of Cardiovascular and Metabolic Medicine (LICAMM), University of Leeds, Clarendon Way, Leeds, LS2 9JT, UK.|Department of Cardiology, Leeds Teaching Hospitals NHS Trust, Leeds, LS1 3EX, UK.
authors.forename: Sven
authors.initials: S
authors.lastname: Plein
authors.affiliation: Multidisciplinary Cardiovascular Research Centre (MCRC) & Leeds Institute of Cardiovascular and Metabolic Medicine (LICAMM), University of Leeds, Clarendon Way, Leeds, LS2 9JT, UK. j.greenwood@leeds.ac.uk.|Department of Cardiology, Leeds Teaching Hospitals NHS Trust, Leeds, LS1 3EX, UK. j.greenwood@leeds.ac.uk.
authors.forename: John P
authors.initials: JP
authors.lastname: Greenwood
mesh_terms: D000200:Action Potentials; D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D001696:Biomechanical Phenomena; D002037:Bundle-Branch Block / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009200:Myocardial Contraction; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013314:Stress, Mechanical; D013318:Stroke Volume; D013997:Time Factors; D065467:Transcatheter Aortic Valve Replacement / Q000009:adverse effects*; D016896:Treatment Outcome; D016277:Ventricular Function, Left; D020257:Ventricular Remodeling
keywords: Aortic valve stenosis; Cardiovascular magnetic resonance; Left bundle branch block; Trans-catheter aortic valve implantation; Ventricular ejection fraction; Ventricular remodeling