title: Cardiac resynchronisation therapy in patients with heart failure and a normal QRS duration: the RESPOND study.
abstract: OBJECTIVE
  To evaluate the clinical response to cardiac resynchronisation therapy (CRT) in patients with heart failure and a normal QRS duration (<120 ms).
  
  
  METHODS
  Single centre.
  
  
  METHODS
  60 patients with heart failure and a normal QRS duration receiving optimal pharmacological treatment (OPT).
  
  
  METHODS
  Patients were randomly assigned to CRT (n=29) or to a control group (OPT, n=31). Cardiovascular magnetic resonance was used in order to avoid scar at the site of left ventricular (LV) lead deployment.
  
  
  METHODS
  The primary end point was a change in 6 min walking distance (6-MWD). Other measures included a change in quality of life scores (Minnesota Living with Heart Failure questionnaire) and New York Heart Association class.
  
  
  RESULTS
  In 93% of implantations, the LV lead was deployed over non-scarred myocardium. At 6 months, the 6-MWD increased with CRT compared with OPT (p<0.0001), with more patients reaching a ≥25% increase (51.7% vs 12.9%, p=0.0019). Compared with OPT, CRT led to an improvement in quality-of-life scores (p=0.0265) and a reduction in NYHA class (p<0.0001). The composite clinical score (survival for 6 months free of heart failure hospitalisations plus improvement by one or more NYHA class or by ≥25% in 6-MWD) was better in CRT than in OPT (83% vs 23%, respectively; p<0.0001). Although no differences in total or cardiovascular mortality emerged between OPT and CRT, patients receiving OPT had a higher risk of death from pump failure than patients assigned to CRT (HR=8.41, p=0.0447) after a median follow-up of 677.5 days.
  
  
  CONCLUSIONS
  CRT leads to an improvement in symptoms, exercise capacity and quality of life in patients with heart failure and a normal QRS duration. (ClinicalTrials.gov number, NCT00480051.).
authors.affiliation: Center for Cardiovascular Sciences, University of Birmingham, Queen Elizabeth Hospital, Birmingham, UK.
authors.forename: Paul W X
authors.initials: PW
authors.lastname: Foley
authors.forename: Kiran
authors.initials: K
authors.lastname: Patel
authors.forename: Nick
authors.initials: N
authors.lastname: Irwin
authors.forename: John E
authors.initials: JE
authors.lastname: Sanderson
authors.forename: Michael P
authors.initials: MP
authors.lastname: Frenneaux
authors.forename: Russell E A
authors.initials: RE
authors.lastname: Smith
authors.forename: Berthold
authors.initials: B
authors.lastname: Stegemann
authors.forename: Francisco
authors.initials: F
authors.lastname: Leyva
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D058406:Cardiac Resynchronization Therapy / Q000379:methods*; D004562:Electrocardiography; D004812:Epidemiologic Methods; D005080:Exercise Test / Q000379:methods; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D011788:Quality of Life; D016896:Treatment Outcome; D014463:Ultrasonography; D016138:Walking / Q000502:physiology