title: Impact of cardiac resynchronization therapy on the severity of mitral regurgitation.
abstract: OBJECTIVE
  Functional mitral regurgitation (MR) could be managed by both cardiac resynchronization therapy (CRT) and mitral-valve surgery. Clinical decision making regarding the appropriateness of mitral-valve surgery vs. CRT is a challenging task. This study assessed the prevalence and prognosis of various degrees of functional MR in CRT candidates. Additionally, we sought to identify functional MR patients who either can be adequately managed by CRT only or will need surgery.
  
  
  RESULTS
  Cardiac resynchronization therapy recipients (n= 794) were followed-up for 26 ± 18 months. Mitral regurgitation severity was quantified on scale 0-4. Cardiac resynchronization therapy responders were identified based on improvement in the New York Heart Association class and left-ventricular ejection fraction. Severity of MR and LV reverse remodelling were assessed at 3 and 12 months. Predictors of long-term MR change and CRT response were explored with multivariable models. Mitral regurgitation was present in 86%, with 35% prevalence of advanced MR (grade 3-4). Improvement of MR ≥ 1° after 12 months occurred in 46% of patients. It was relatively more frequent in patients with advanced MR at baseline (63%, P< 0.01). Baseline MR severity and change in MR at 3-month follow-up predicted response to CRT. Patients with ≥ 1° MR improvement at 12 months had more reverse remodelling compared with those with no change or worsening of MR.
  
  
  CONCLUSIONS
  Mitral regurgitation improvement at 3 months predicts CRT response and MR improvement at 12-month follow-up. This finding could have implications for subsequent MR surgical therapies.
authors.affiliation: Texas Cardiac Arrhythmia Institute at St David's Medical Center, Austin, TX, USA.
authors.forename: Luigi
authors.initials: L
authors.lastname: Di Biase
authors.forename: Angelo
authors.initials: A
authors.lastname: Auricchio
authors.forename: Prasant
authors.initials: P
authors.lastname: Mohanty
authors.forename: Rong
authors.initials: R
authors.lastname: Bai
authors.forename: Josef
authors.initials: J
authors.lastname: Kautzner
authors.forename: Paolo
authors.initials: P
authors.lastname: Pieragnoli
authors.forename: Francois
authors.initials: F
authors.lastname: Regoli
authors.forename: Antonio
authors.initials: A
authors.lastname: Sorgente
authors.forename: Giulio
authors.initials: G
authors.lastname: Spinucci
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Ricciardi
authors.forename: Antonio
authors.initials: A
authors.lastname: Michelucci
authors.forename: Laura
authors.initials: L
authors.lastname: Perrotta
authors.forename: Francesco
authors.initials: F
authors.lastname: Faletra
authors.forename: Hancha
authors.initials: H
authors.lastname: Mlcochová
authors.forename: Kamil
authors.initials: K
authors.lastname: Sedlacek
authors.forename: Robert
authors.initials: R
authors.lastname: Canby
authors.forename: Javier E
authors.initials: JE
authors.lastname: Sanchez
authors.forename: Rodney
authors.initials: R
authors.lastname: Horton
authors.forename: J David
authors.initials: JD
authors.lastname: Burkhardt
authors.forename: Tiziano
authors.initials: T
authors.lastname: Moccetti
authors.forename: Luigi
authors.initials: L
authors.lastname: Padeletti
authors.forename: Andrea
authors.initials: A
authors.lastname: Natale
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D058406:Cardiac Resynchronization Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000601:surgery; D008944:Mitral Valve Insufficiency / Q000453:epidemiology / Q000628:therapy*; D015999:Multivariate Analysis; D015995:Prevalence; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013997:Time Factors; D016896:Treatment Outcome