title: Prognostic importance of change in QRS duration over time associated with left ventricular dysfunction in patients with congestive heart failure: the DIAMOND study.
abstract: BACKGROUND
  The prognostic importance reported for QRS duration in patients with heart failure (HF) and left ventricular dysfunction varies. No prior study has investigated the prognostic importance of change in QRS duration over time.
  
  
  RESULTS
  The Danish Investigations and Arrhythmia ON Dofetilide (DIAMOND) study randomized 1518 patients with HF to dofetilide (class III antiarrhythmic drug) or placebo. All patients had left ventricular dysfunction. QRS duration was systematically measured at randomization and every 3 months after that. During 10 years of follow-up, 1324 (89%) of the patients died. QRS duration increased from baseline by 1.36 ms (95% confidence interval [CI]: -0.26 to -2.98; P = .1) after 12 months and by 3.65 ms (CI: 0.22-7.07; P = .04) after 24 months. QRS duration measured at baseline was not of prognostic significance after multivariable adjustment (adjusted hazard ratio [HR] 1.01, CI: 0.99-1.04; P = .2 per 10-ms increment in QRS duration). The adjusted relative risk associated with a 10-ms increase in QRS duration over time was 2% (HR 1.02, CI: 1.01-1.04; P = .03). A 10-ms increment in QRS 12 months after randomization was associated with a HR of 1.05 (CI: 1.00-1.09; P = .03).
  
  
  CONCLUSIONS
  In patients with left ventricular dysfunction and HF, QRS duration increased over time and the increase was associated with increasing mortality.
authors.affiliation: The Heart Centre, University Hospital of Copenhagen, Rigshospitalet, Copenhagen, Denmark. ELF@heart.dk
authors.forename: Emil Loldrup
authors.initials: EL
authors.lastname: Fosbøl
authors.forename: Marie
authors.initials: M
authors.lastname: Seibaek
authors.forename: Bente
authors.initials: B
authors.lastname: Brendorp
authors.forename: Christian
authors.initials: C
authors.lastname: Torp-Pedersen
authors.forename: Lars
authors.initials: L
authors.lastname: Køber
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003718:Denmark / Q000453:epidemiology; D004311:Double-Blind Method; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000175:diagnosis* / Q000401:mortality / Q000503:physiopathology*; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D015996:Survival Rate / Q000639:trends; D013997:Time Factors; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis* / Q000401:mortality / Q000503:physiopathology*