title: Acute Hemodynamic Response to Cardiac Resynchronization in Dilated Cardiomyopathy: Effect on Late Mitral Regurgitation.
abstract: BACKGROUND
  Functional mitral regurgitation (FMR) is associated with reduced survival in dilated cardiomyopathy (DCM). Cardiac resynchronization therapy (CRT) can improve FMR. We sought to identify the predictors of FMR improvement after CRT in DCM.
  
  
  METHODS
  From January 2003 to December 2013, 430 DCM patients consecutively enrolled were retrospectively analyzed. Inclusion criteria were successful CRT implantation in the presence of conventional indications (i.e., left bundle branch block, left ventricular ejection fraction ≤35%, New York Heart Association functional class ≥II) and moderate-to-severe FMR at the time of procedure. Early echocardiographic evaluation after CRT implantation (median 2.5 days) has been performed in each patient. Improvement in FMR (absent/mild) at midterm (7 months; interquartile range 4-10) was considered as the primary study end point.
  
  
  RESULTS
  A total of 44 patients (10% of the overall cohort) were included. A significant reduction in FMR severity was observed in 21 patients (48%) at midterm after CRT (median time 7 months). No preimplantation variables predicted FMR evolution, but FMR improvement at midterm was strongly predicted by an acute favorable hemodynamic response (persistence/development of normal right ventricular function and 10-mm Hg decrease or normalization [≤35 mm Hg] of systolic pulmonary artery pressure) at postimplantation echocardiography (odds ratio: 13.7; 95% confidence interval: 1.27-42.8; P = 0.016). FMR improvement at midterm was stable during follow-up and was associated with superior long-term transplant-free survival (P = 0.022).
  
  
  CONCLUSIONS
  Stable FMR improvement frequently occurs after CRT implantation in DCM and is associated with improved transplant-free survival. Echocardiographic evaluation of acute hemodynamic response to CRT is helpful to early identification of the favorable FMR evolution.
authors.affiliation: Cardiovascular Department, "Ospedali Riuniti" and University of Trieste, Trieste, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Stolfo
authors.affiliation: Cardiovascular Department, "Ospedali Riuniti" and University of Trieste, Trieste, Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Tonet
authors.affiliation: Cardiovascular Department, "Ospedali Riuniti" and University of Trieste, Trieste, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Barbati
authors.affiliation: Cardiovascular Department, "Ospedali Riuniti" and University of Trieste, Trieste, Italy.
authors.forename: Marta
authors.initials: M
authors.lastname: Gigli
authors.affiliation: Cardiovascular Department, "Ospedali Riuniti" and University of Trieste, Trieste, Italy.
authors.forename: Bruno
authors.initials: B
authors.lastname: Pinamonti
authors.affiliation: Cardiovascular Department, "Ospedali Riuniti" and University of Trieste, Trieste, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Zecchin
authors.affiliation: Cardiovascular Department, "Ospedali Riuniti" and University of Trieste, Trieste, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Ramani
authors.affiliation: Cardiovascular Department, "Ospedali Riuniti" and University of Trieste, Trieste, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Merlo
authors.affiliation: Cardiovascular Department, "Ospedali Riuniti" and University of Trieste, Trieste, Italy.
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Sinagra
mesh_terms: D058406:Cardiac Resynchronization Therapy; D002311:Cardiomyopathy, Dilated / Q000150:complications / Q000503:physiopathology* / Q000628:therapy*; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000150:complications / Q000503:physiopathology* / Q000628:therapy*; D012189:Retrospective Studies; D013997:Time Factors
keywords: cardiac resynchronization therapy; dilated cardiomyopathy; echocardiography; mitral regurgitation; right ventricle