title: Cardiac-resynchronization therapy with or without an implantable defibrillator in advanced chronic heart failure.
abstract: BACKGROUND
  We tested the hypothesis that prophylactic cardiac-resynchronization therapy in the form of biventricular stimulation with a pacemaker with or without a defibrillator would reduce the risk of death and hospitalization among patients with advanced chronic heart failure and intraventricular conduction delays.
  
  
  METHODS
  A total of 1520 patients who had advanced heart failure (New York Heart Association class III or IV) due to ischemic or nonischemic cardiomyopathies and a QRS interval of at least 120 msec were randomly assigned in a 1:2:2 ratio to receive optimal pharmacologic therapy (diuretics, angiotensin-converting-enzyme inhibitors, beta-blockers, and spironolactone) alone or in combination with cardiac-resynchronization therapy with either a pacemaker or a pacemaker-defibrillator. The primary composite end point was the time to death from or hospitalization for any cause.
  
  
  RESULTS
  As compared with optimal pharmacologic therapy alone, cardiac-resynchronization therapy with a pacemaker decreased the risk of the primary end point (hazard ratio, 0.81; P=0.014), as did cardiac-resynchronization therapy with a pacemaker-defibrillator (hazard ratio, 0.80; P=0.01). The risk of the combined end point of death from or hospitalization for heart failure was reduced by 34 percent in the pacemaker group (P<0.002) and by 40 percent in the pacemaker-defibrillator group (P<0.001 for the comparison with the pharmacologic-therapy group). A pacemaker reduced the risk of the secondary end point of death from any cause by 24 percent (P=0.059), and a pacemaker-defibrillator reduced the risk by 36 percent (P=0.003).
  
  
  CONCLUSIONS
  In patients with advanced heart failure and a prolonged QRS interval, cardiac-resynchronization therapy decreases the combined risk of death from any cause or first hospitalization and, when combined with an implantable defibrillator, significantly reduces mortality.
authors.affiliation: Division of Cardiology, University of Colorado Health Sciences Center, Denver, CO 80262, USA. michael.bristow@uchsc.edu
authors.forename: Michael R
authors.initials: MR
authors.lastname: Bristow
authors.forename: Leslie A
authors.initials: LA
authors.lastname: Saxon
authors.forename: John
authors.initials: J
authors.lastname: Boehmer
authors.forename: Steven
authors.initials: S
authors.lastname: Krueger
authors.forename: David A
authors.initials: DA
authors.lastname: Kass
authors.forename: Teresa
authors.initials: T
authors.lastname: De Marco
authors.forename: Peter
authors.initials: P
authors.lastname: Carson
authors.forename: Lorenzo
authors.initials: L
authors.lastname: DiCarlo
authors.forename: David
authors.initials: D
authors.lastname: DeMets
authors.forename: Bill G
authors.initials: BG
authors.lastname: White
authors.forename: Dale W
authors.initials: DW
authors.lastname: DeVries
authors.forename: Arthur M
authors.initials: AM
authors.lastname: Feldman
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000368:Aged; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use*; D002908:Chronic Disease; D003131:Combined Modality Therapy; D017147:Defibrillators, Implantable; D004232:Diuretics / Q000627:therapeutic use*; D005260:Female; D006333:Heart Failure / Q000150:complications / Q000188:drug therapy / Q000401:mortality / Q000628:therapy*; D006760:Hospitalization; D006801:Humans; D008297:Male; D010138:Pacemaker, Artificial; D012306:Risk; D013148:Spironolactone / Q000627:therapeutic use; D018487:Ventricular Dysfunction, Left / Q000150:complications / Q000628:therapy
chemical_list: D000319:Adrenergic beta-Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors; D004232:Diuretics; D013148:Spironolactone