title: Differential prognostic importance of QRS duration in heart failure and acute myocardial infarction associated with left ventricular dysfunction.
abstract: OBJECTIVE
  Studies of the prognostic importance of QRS duration in patients with heart failure (HF) have shown conflicting results and few studies have estimated the importance after myocardial infarction (MI).
  
  
  METHODS
  The Danish Investigations and Arrhythmia ON Dofetilide (DIAMOND) study randomised 3028 patients to dofetilide (class III antiarrhythmic) or placebo. The study consisted of two almost identical trials conducted simultaneously. One trial included 1518 patients with chronic HF and the other trial 1510 patients with a recent MI. All patients had left ventricular dysfunction. Dofetilide did not influence mortality in either trial. QRS duration was systematically measured at randomisation and was available in 2972 patients.
  
  
  RESULTS
  Over a 10 year observation period 1037 (70%) patients in the MI study and 1324 (87%) in the HF study died. In the MI study, risk of death increased 6% for each 10 ms increase in QRS duration (HR=1.06/10 ms increase in QRS (CI=1.04-1.09), p<0.0001) whereas QRS duration had no influence in the HF study after multivariable adjustment. The difference between HF and MI was significant (p<0.0004 for interaction).
  
  
  CONCLUSIONS
  QRS duration predicts death in patients with left ventricular dysfunction who have suffered MI. In patients with HF QRS duration is not predictive of mortality.
authors.affiliation: The Heart Centre, University Hospital of Copenhagen, Rigshospitalet, Blegdamsvej 9, DK 2100 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: Daniél Vega
authors.initials: DV
authors.lastname: Møller
authors.forename: Mads
authors.initials: M
authors.lastname: Ersbøll
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; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000401:mortality* / Q000503:physiopathology*; D011379:Prognosis; D016016:Proportional Hazards Models; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology*