Cardiac-resynchronization therapy with or without an implantable defibrillator in advanced chronic heart failure.
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.
Bristow
Michael R
MR
Division of Cardiology, University of Colorado Health Sciences Center, Denver, CO 80262, USA. michael.bristow@uchsc.edu
Saxon
Leslie A
LA
Boehmer
John
J
Krueger
Steven
S
Kass
David A
DA
De Marco
Teresa
T
Carson
Peter
P
DiCarlo
Lorenzo
L
DeMets
David
D
White
Bill G
BG
DeVries
Dale W
DW
Feldman
Arthur M
AM
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
D000319:Adrenergic beta-Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors; D004232:Diuretics; D013148:Spironolactone