title: Biventricular implantable cardioverter defibrillators improve survival compared with biventricular pacing alone in patients with severe left ventricular dysfunction.
abstract: BACKGROUND
  Biventricular cardiac pacemakers provide important hemodynamic benefit in selected patients with heart failure and severe left ventricular (LV) dysfunction. Nevertheless, these patients remain at high mortality risk. To address this issue, we examined mortality outcome in patients with heart failure treated with biventricular pacemakers alone and those treated with biventricular implantable cardioverter defibrillators (ICDs).
  
  
  RESULTS
  The study population consisted of 126 consecutive patients with LV dysfunction and heart failure who received either a biventricular ICD (n = 62) or a biventricular pacemaker (n = 64) between January 1998 and December 2002. A minimum 12 months of follow-up was obtained in all survivors. ICD indications were conventional in all patients. Kaplan-Meier actuarial method and log rank statistics were used to calculate and compare survival rates in both groups. Comparison of mortality rates utilized Chi-square test. The two groups had similar clinical and demographic features, LV ejection fraction, and medication use. Average follow-up times were 13 +/- 11.8 months (range 4-60) and 18 +/- 13.2 months (range 0.5-53) for biventricular ICD and pacemaker groups, respectively. Overall mortality rate was significantly lower in the biventricular ICD group (13%, 8 deaths) compared to the pacemaker group (41%, 26 deaths) (P = 0.01). Further, the predominant survival benefit for ICD-treated patients becomes evident after the first 12 months of follow-up.
  
  
  CONCLUSIONS
  The findings in this study, although necessarily limited in their interpretation by the absence of treatment randomization, suggest that biventricular ICDs offer a survival benefit compared to biventricular pacing alone. Furthermore, this benefit may be most apparent if other clinical factors do not preclude patient survival >1 year postimplant.
authors.affiliation: Cardiac Arrhythmia Center, University of Minnesota Medical School, Minneapolis, Minnesota, USA.
authors.forename: Cengiz
authors.initials: C
authors.lastname: Ermis
authors.forename: Keith G
authors.initials: KG
authors.lastname: Lurie
authors.forename: Alan X
authors.initials: AX
authors.lastname: Zhu
authors.forename: Joanne
authors.initials: J
authors.lastname: Collins
authors.forename: Laura
authors.initials: L
authors.lastname: Vanheel
authors.forename: Scott
authors.initials: S
authors.lastname: Sakaguchi
authors.forename: Fei
authors.initials: F
authors.lastname: Lu
authors.forename: Scott
authors.initials: S
authors.lastname: Pham
authors.forename: David G
authors.initials: DG
authors.lastname: Benditt
mesh_terms: D000368:Aged; D017147:Defibrillators, Implantable / Q000706:statistics & numerical data*; D019544:Equipment Failure Analysis / Q000379:methods*; D005260:Female; D006333:Heart Failure / Q000401:mortality* / Q000628:therapy*; D006801:Humans; D008297:Male; D017063:Outcome Assessment, Health Care / Q000379:methods; D010138:Pacemaker, Artificial / Q000706:statistics & numerical data*; D011379:Prognosis; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D013534:Survival; D016019:Survival Analysis; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology; D018487:Ventricular Dysfunction, Left / Q000401:mortality* / Q000628:therapy*