title: Very long term follow-up of cardiac resynchronization therapy: clinical outcome and predictors of mortality.
abstract: BACKGROUND
  Cardiac resynchronization therapy (CRT) improves symptoms, left ventricular ejection fraction (LVEF) and survival in patients with heart failure and wide QRS, however, long term clinical outcome is unknown.
  
  
  OBJECTIVE
  To identify predictors of mortality and evaluate the effects of CRT after long term follow-up.
  
  
  METHODS
  Consecutive patients treated with CRT between 1997 and 2002 were included. We collected clinical information from patient files. Patients who were still alive underwent echocardiography and clinical evaluation.
  
  
  RESULTS
  We included 179 patients (median age 65.5 years, 144 male). Median follow-up for survival was 4.0 years. Mortality at one and five years was 15% and 53%, respectively. Predictors of mortality were, ischaemic heart disease (IHD), higher NYHA class and lower LVEF (<22.5%) at baseline, and no improvement in NYHA class at early follow-up. NYHA class remained stable from early to long term follow-up after a median of 5.1 years. In patients with non-IHD median LVEF increased significantly from early to long term follow-up (39% vs. 50% p=0.007).
  
  
  CONCLUSIONS
  Predictors of mortality in patients with CRT are IHD, lower LVEF and higher NYHA class at baseline, and no symptomatic response to CRT. After 5 years follow-up, clinical effects are sustained, and in patients with non-IHD further improvements in LVEF are observed.
authors.affiliation: Aarhus University Hospital, Skejby, Denmark. MADS.BRIX.KRONBORG@KI.AU.DK
authors.forename: Mads Brix
authors.initials: MB
authors.lastname: Kronborg
authors.forename: Peter Thomas
authors.initials: PT
authors.lastname: Mortensen
authors.forename: Rikke Esberg
authors.initials: RE
authors.lastname: Kirkfeldt
authors.forename: Jens Cosedis
authors.initials: JC
authors.lastname: Nielsen
mesh_terms: D000368:Aged; D002304:Cardiac Pacing, Artificial; D004452:Echocardiography; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000401:mortality / Q000628:therapy*; D006801:Humans; D008297:Male; D013318:Stroke Volume; D016896:Treatment Outcome