title: Association of persistent or worsened echocardiographic dyssynchrony with unfavourable clinical outcomes in heart failure patients with narrow QRS width: a subgroup analysis of the EchoCRT trial.
abstract: OBJECTIVE
  EchoCRT was a randomized trial of cardiac resynchronization therapy (CRT) in severely symptomatic heart failure (HF) patients with narrow QRS width <130 ms, ejection fraction ≤35%, and echocardiographic dyssynchrony. All received CRT implants which were then randomized to CRT-On or CRT-Off. While the trial showed no benefit of CRT to these patients, the aim of this subgroup analysis was to test the hypothesis that persistent or worsening dyssynchrony is associated with unfavourable clinical outcomes.
  
  
  RESULTS
  We studied 614 EchoCRT patients with baseline and 6-month echocardiograms. Baseline dyssynchrony required for study inclusion was either tissue Doppler imaging longitudinal velocity delay ≥80 ms or speckle-tracking radial strain delay ≥130 ms. Persistent dyssynchrony at 6 months was observed similarly in both groups (77% in CRT-On; 76% in CRT-Off). Persistent dyssynchrony was associated with a significantly higher primary end point of death or HF hospitalization (HR = 1.54, 95% CI 1.03-2.30, P = 0.03), and in particular secondary endpoint of HF hospitalization (HR = 1.66, 95% CI 1.07-2.57, P = 0.02). HF hospitalizations were also associated with worsening longitudinal dyssynchrony (HR = 1.45, 95% CI 1.02-2.05, P = 0.037), and worsening radial dyssynchrony (HR = 1.81, 95% CI 1.16-2.81, P = 0.008). Associations of persistent or worsening dyssynchrony with outcomes were similar in CRT-Off and CRT-On groups.
  
  
  CONCLUSIONS
  Persistent or worsening echocardiographic dyssynchrony in HF patients with narrow QRS width was a marker for unfavourable clinical outcomes unaffected by CRT. In particular, echocardiographic dyssynchrony on follow-up was strongly associated with HF hospitalizations and appears to be a prognostic marker of disease severity.
authors: University of Pittsburgh, Scaife 564, 200 Lothrop Street, Pittsburgh, PA 15213-2582, USA gorcsanj@upmc.edu.
authors: John
authors: J
authors: Gorcsan
authors: Aalborg University, Aalborg, Denmark.
authors: Peter
authors: P
authors: Sogaard
authors: Leiden University Medical Center, Leiden, The Netherlands.
authors: Jeroen J
authors: JJ
authors: Bax
authors: Massachusetts General Hospital, Harvard Medical School, Boston, USA.
authors: Jagmeet P
authors: JP
authors: Singh
authors: Division of Cardiovascular Medicine, Ohio State University Medical Center, Davis Heart and Lung Research Institute, Columbus, USA gorcsanj@upmc.edu.
authors: William T
authors: WT
authors: Abraham
authors: Department of Cardiology, Division of Cardiovascular Medicine and Howard Gilmanand Ron and Jean Schiavone Institutes, State University of New York Downstate College of Medicine, New York, USA.
authors: Jeffrey S
authors: JS
authors: Borer
authors: University of Bergen, Stavanger University Hospital, Stavanger, Norway.
authors: Kenneth
authors: K
authors: Dickstein
authors: Nouvelles Cliniques Nantaises, Nantes, France.
authors: Daniel
authors: D
authors: Gras
authors: Monash Centre of Cardiovascular Research and Education in Therapeutics, Melbourne, VIC, Australia.
authors: Henry
authors: H
authors: Krum
authors: Cardiology Department, Thorax Institute, Hospital Clinic, University of Barcelona, Barcelona, Spain.
authors: Josep
authors: J
authors: Brugada
authors: Robertson Centre for Biostatistics, University of Glasgow, Glasgow, United Kingdom.
authors: Michele
authors: M
authors: Robertson
authors: Robertson Centre for Biostatistics, University of Glasgow, Glasgow, United Kingdom.
authors: Ian
authors: I
authors: Ford
authors: Department of Cardiology, University Heart Center Zurich, Zurich, Switzerland.
authors: Johannes
authors: J
authors: Holzmeister
authors: Department of Cardiology, University Heart Center Zurich, Zurich, Switzerland gorcsanj@upmc.edu.
authors: Frank
authors: F
authors: Ruschitzka
mesh_terms: D001145:Arrhythmias, Cardiac / Q000401:mortality / Q000503:physiopathology / Q000628:therapy; D058406:Cardiac Resynchronization Therapy / Q000379:methods*; D018618:Echocardiography, Doppler, Color; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D006760:Hospitalization; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*
keywords: Cardiac resynchronization therapy; Echocardiography; Heart failure