title: Left ventricular dyssynchrony predicts response and prognosis after cardiac resynchronization therapy.
abstract: OBJECTIVE
  This study was designed to predict the response and prognosis after cardiac resynchronization therapy (CRT) in patients with end-stage heart failure (HF).
  
  
  BACKGROUND
  Cardiac resynchronization therapy improves HF symptoms, exercise capacity, and left ventricular (LV) function. Because not all patients respond, preimplantation identification of responders is needed. In the present study, response to CRT was predicted by the presence of LV dyssynchrony assessed by tissue Doppler imaging. Moreover, the prognostic value of LV dyssynchrony in patients undergoing CRT was assessed.
  
  
  METHODS
  Eighty-five patients with end-stage HF, QRS duration >120 ms, and left bundle-branch block were evaluated by tissue Doppler imaging before CRT. At baseline and six months follow-up, New York Heart Association functional class, quality of life and 6-min walking distance, LV volumes, and LV ejection fraction were determined. Events (death, hospitalization for decompensated HF) were obtained during one-year follow-up.
  
  
  RESULTS
  Responders (74%) and nonresponders (26%) had comparable baseline characteristics, except for a larger dyssynchrony in responders (87 +/- 49 ms vs. 35 +/- 20 ms, p < 0.01). Receiver-operator characteristic curve analysis demonstrated that an optimal cutoff value of 65 ms for LV dyssynchrony yielded a sensitivity and specificity of 80% to predict clinical improvement and of 92% to predict LV reverse remodeling. Patients with dyssynchrony >/=65 ms had an excellent prognosis (6% event rate) after CRT as compared with a 50% event rate in patients with dyssynchrony <65 ms (p < 0.001).
  
  
  CONCLUSIONS
  Patients with LV dyssynchrony >/=65 ms respond to CRT and have an excellent prognosis after CRT.
authors.affiliation: Leiden University Medical Center, Leiden, The Netherlands. jbax@knoware.nl
authors.forename: Jeroen J
authors.initials: JJ
authors.lastname: Bax
authors.forename: Gabe B
authors.initials: GB
authors.lastname: Bleeker
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Marwick
authors.forename: Sander G
authors.initials: SG
authors.lastname: Molhoek
authors.forename: Eric
authors.initials: E
authors.lastname: Boersma
authors.forename: Paul
authors.initials: P
authors.lastname: Steendijk
authors.forename: Ernst E
authors.initials: EE
authors.lastname: van der Wall
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Schalij
mesh_terms: D000368:Aged; D002304:Cardiac Pacing, Artificial; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy; D010138:Pacemaker, Artificial; D011237:Predictive Value of Tests; D011379:Prognosis; D012680:Sensitivity and Specificity; D013318:Stroke Volume / Q000502:physiology; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis* / Q000503:physiopathology*; D020257:Ventricular Remodeling / Q000502:physiology