title: Rethinking cardiac resynchronization therapy: the impact of ventricular dyssynchrony on outcome.
abstract: OBJECTIVE
  To analyze whether left ventricular dyssynchrony (LVD) at baseline is predictive for long-term outcome in heart failure (CHF) patients with left ventricular (LV) dysfunction and conduction disturbances treated with cardiac resynchronization therapy (CRT).
  
  
  METHODS
  In 535 consecutive individuals with CHF scheduled for implantation of a CRT device, LVD was assessed by tissue Doppler imaging (TDI), defined as an electromechanical delay (EMD) difference of ≥40 ms in 2 opposed left ventricular wall regions (septal vs. lateral, anterior vs. inferior). All-cause mortality, heart transplantation, or assist device implantation was defined as combined primary end point. Secondary end points were measures of reverse LV remodeling and of symptomatic improvement.
  
  
  RESULTS
  Mean follow-up was 68 ± 36 [range: 4-150] months. LVD at baseline was present in 308 patients (61%). Of these, 24% reached the combined primary endpoint in contrast to 58% of patients without LVD (p < 0.001). Furthermore, patients with LVD showed pronounced improvement of all secondary end point parameters. In our cohort LVD was an independent predictor for outcome (hazard ratio [95% CI]: 0.30 [0.21-0.42], p < 0.001).
  
  
  CONCLUSIONS
  LVD at baseline as assessed by TDI is associated with a more pronounced clinical improvement and is a predictor for transplant-free long-term survival in CRT recipients.
authors.affiliation: Department of Cardiology, Heart and Diabetes Centre of North-Rhine Westphalia, Ruhr University Bochum, Bad Oeynhausen, Germany. Electronic address: Cchrprinz@aol.com.
authors.forename: Christian
authors.initials: C
authors.lastname: Prinz
authors.forename: Cinthia Duarte
authors.initials: CD
authors.lastname: Felice
authors.forename: Roman
authors.initials: R
authors.lastname: Lehmann
authors.forename: Maria
authors.initials: M
authors.lastname: Schwarz
authors.forename: Eva-Maria
authors.initials: EM
authors.lastname: Prinz
authors.forename: Thomas
authors.initials: T
authors.lastname: Bitter
authors.forename: Jürgen
authors.initials: J
authors.lastname: Vogt
authors.forename: Barbara
authors.initials: B
authors.lastname: Lamp
authors.forename: Lothar
authors.initials: L
authors.lastname: Faber
authors.forename: Dieter
authors.initials: D
authors.lastname: Horstkotte
mesh_terms: D000368:Aged; D058406:Cardiac Resynchronization Therapy / Q000379:methods* / Q000639:trends; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012189:Retrospective Studies; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology* / Q000628:therapy*; D020257:Ventricular Remodeling / Q000502:physiology*
keywords: Cardiac resynchronization therapy (CRT); Electromechanical delay; Long-term follow-up; Outcome; Tissue Doppler imaging; Ventricular dyssynchrony