title: Impact of clinical and echocardiographic response to cardiac resynchronization therapy on long-term survival.
abstract: BACKGROUND
  Clinical or echocardiographic mid-term responses to cardiac resynchronization therapy (CRT) may have a different influence on a long-term prognosis of heart failure patients treated with CRT. The aim of the evaluation was to establish which definition of response to CRT, clinical or echocardiographic, best predicts long-term prognosis.
  
  
  RESULTS
  A total of 679 heart failure patients treated with CRT were included. All the patients underwent a complete history and physical examination and transthoracic echocardiogram prior to CRT implantation and at 6-month follow-up. The clinical and echocardiographic responses to CRT were defined based on clinical improvement (≥1 NYHA class) and LV reverse remodelling (reduction in LV end-systolic volume ≥15%) at 6-month follow-up, respectively. All the patients were prospectively followed up for the occurrence of death. The mean age was 65 ± 11 years and 79% of the patients were male. At 6-month follow-up, 510 (77%) patients showed clinical response to CRT and 412 (62%) patients showed echocardiographic response to CRT. During a mean follow-up of 37 ± 22 months, 140 (21%) patients died. Clinical and echocardiographic responses to CRT were both significantly related to all-cause mortality on univariable analysis. However, on multivariable Cox-regression analysis only echocardiographic response to CRT was independently associated with superior survival (hazard ratio: 0.38; 95% CI: 0.27-0.50; P < 0.001).
  
  
  CONCLUSIONS
  In a large population of heart failure patients treated with CRT, the reduction in LV end-systolic volume at the mid-term follow-up demonstrated to be a better predictor of long-term survival than improvement in the clinical status.
authors.affiliation: Department of Cardiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, the Netherlands.
authors.forename: Matteo
authors.initials: M
authors.lastname: Bertini
authors.forename: Ulas
authors.initials: U
authors.lastname: Höke
authors.forename: Rutger J
authors.initials: RJ
authors.lastname: van Bommel
authors.forename: Arnold C T
authors.initials: AC
authors.lastname: Ng
authors.forename: Miriam
authors.initials: M
authors.lastname: Shanks
authors.forename: Gaetano
authors.initials: G
authors.lastname: Nucifora
authors.forename: Dominique
authors.initials: D
authors.lastname: Auger
authors.forename: C Jan Willem
authors.initials: CJ
authors.lastname: Borleffs
authors.forename: Eva P M
authors.initials: EP
authors.lastname: van Rijnsoever
authors.forename: Lieselot
authors.initials: L
authors.lastname: van Erven
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Schalij
authors.forename: Nina Ajmone
authors.initials: NA
authors.lastname: Marsan
authors.forename: Jeroen J
authors.initials: JJ
authors.lastname: Bax
authors.forename: Victoria
authors.initials: V
authors.lastname: Delgado
mesh_terms: D000368:Aged; D058406:Cardiac Resynchronization Therapy; D004452:Echocardiography / Q000379:methods*; D018618:Echocardiography, Doppler, Color; D004562:Electrocardiography; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008297:Male; D011379:Prognosis; D011446:Prospective Studies; D015996:Survival Rate; D020257:Ventricular Remodeling / Q000502:physiology