title: Surface electrocardiogram to predict outcome in candidates for cardiac resynchronization therapy: a sub-analysis of the CARE-HF trial.
abstract: OBJECTIVE
  In CARE-HF, cardiac resynchronization therapy (CRT) lowered morbidity and mortality in patients with moderate to severe heart failure. We examined whether baseline and follow-up electrocardiographic characteristics might predict long-term outcome.
  
  
  RESULTS
  CARE-HF randomly assigned 409 patients to medical therapy (MT) plus CRT, and 404 patients to MT alone. Electrocardiographic measurements were made at baseline during sinus rhythm, and at 3 months during paced or spontaneous rhythm depending on treatment assignment. Favourable outcome was defined as freedom from death, urgent transplantation, or cardiovascular hospitalization. Among patients assigned to CRT, 39% had unfavourable outcomes including 55 deaths. By single variable analysis, (i) prolonged PR interval, left QRS axis (but not QRS duration), and left bundle branch block (BBB) at baseline, and (ii) heart rate, PR, and QRS duration at 3 months predicted unfavourable outcome. By multiple variable analysis, treatment assignment (P = 0.0001), PR (P = 0.0004), and right BBB (P < 0.00013) at baseline predicted outcome, whereas baseline JTc and QRS duration at 3 months predicted all-cause mortality and heart failure hospitalization (P = 0.0071).
  
  
  CONCLUSIONS
  In CARE-HF, QRS duration at baseline did not predict outcome, but QRS at 3 months was a predictor by single variable analysis. Patients with prolonged PR interval and the 5% of patients with right BBB had a particularly high event rate.
authors.affiliation: Département de Cardiologie, Centre Hospitalier Universitaire Pontchaillou, 35033 Rennes cedex 09, France.
authors.forename: Renaud
authors.initials: R
authors.lastname: Gervais
authors.forename: Christophe
authors.initials: C
authors.lastname: Leclercq
authors.forename: Aparna
authors.initials: A
authors.lastname: Shankar
authors.forename: Sandra
authors.initials: S
authors.lastname: Jacobs
authors.forename: Hans
authors.initials: H
authors.lastname: Eiskjaer
authors.forename: Arne
authors.initials: A
authors.lastname: Johannessen
authors.forename: Nick
authors.initials: N
authors.lastname: Freemantle
authors.forename: John G F
authors.initials: JG
authors.lastname: Cleland
authors.forename: Luigi
authors.initials: L
authors.lastname: Tavazzi
authors.forename: Claude
authors.initials: C
authors.lastname: Daubert
mesh_terms: D000368:Aged; D002037:Bundle-Branch Block; D002304:Cardiac Pacing, Artificial; D016001:Confidence Intervals; D004562:Electrocardiography; D005260:Female; D006333:Heart Failure / Q000401:mortality / Q000503:physiopathology* / Q000628:therapy*; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D013997:Time Factors; D016896:Treatment Outcome