title: Comparative effectiveness of cardiac resynchronization therapy with an implantable cardioverter-defibrillator versus defibrillator therapy alone: a cohort study.
abstract: BACKGROUND
  Trials comparing implantable cardioverter-defibrillator (ICD) therapy with cardiac resynchronization therapy with a defibrillator (CRT-D) are limited to selected patients treated at centers with extensive experience.
  
  
  OBJECTIVE
  To compare outcomes after CRT-D versus ICD therapy in contemporary practice.
  
  
  METHODS
  Retrospective cohort study using the National Cardiovascular Data Registry's ICD Registry linked with Medicare claims.
  
  
  METHODS
  780 U.S. hospitals implanting both CRT-D and ICD devices.
  
  
  METHODS
  7090 propensity-matched patients older than 65 years with reduced left ventricular ejection fraction (&lt;0.35) and prolonged QRS duration on electrocardiography (≥120 ms) having CRT-D or ICD implantation between 1 April 2006 and 31 December 2009.
  
  
  METHODS
  Risks for death, readmission, and device-related complications over 3 years.
  
  
  RESULTS
  Compared with ICD therapy, CRT-D was associated with lower risks for mortality (cumulative incidence, 25.7% vs. 29.8%; adjusted hazard ratio [HR], 0.82 [99% CI, 0.73 to 0.93]), all-cause readmission (cumulative incidence, 68.6% vs. 72.8%; adjusted HR, 0.86 [CI, 0.81 to 0.93]), cardiovascular readmission (cumulative incidence, 45.0% vs. 52.4%; adjusted HR, 0.80 [CI, 0.73 to 0.88]), and heart failure readmission (cumulative incidence, 24.3% vs. 29.4%; adjusted HR, 0.78 [CI, 0.69 to 0.88]). It was also associated with greater risks for device-related infection (cumulative incidence, 1.9% vs. 1.0%; adjusted HR, 1.90 [CI, 1.07 to 3.37]). The lower risks for heart failure readmission associated with CRT-D compared with ICD therapy were most pronounced among patients with left bundle branch block or a QRS duration at least 150 ms and in women.
  
  
  CONCLUSIONS
  Patients were not randomly assigned to treatment groups, and few patients could be propensity-matched. The findings may not extend to younger patients or those outside of fee-for-service Medicare.
  
  
  CONCLUSIONS
  In older patients with reduced left ventricular ejection fraction and prolonged QRS duration, CRT-D was associated with lower risks for death and readmission than ICD therapy alone.
  
  
  BACKGROUND
  Agency for Healthcare Research and Quality.
authors.forename: Frederick A
authors.initials: FA
authors.lastname: Masoudi
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Mi
authors.forename: Lesley H
authors.initials: LH
authors.lastname: Curtis
authors.forename: Pamela N
authors.initials: PN
authors.lastname: Peterson
authors.forename: Jeptha P
authors.initials: JP
authors.lastname: Curtis
authors.forename: Gregg C
authors.initials: GC
authors.lastname: Fonarow
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Hammill
authors.forename: Paul A
authors.initials: PA
authors.lastname: Heidenreich
authors.forename: Sana M
authors.initials: SM
authors.lastname: Al-Khatib
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Piccini
authors.forename: Laura G
authors.initials: LG
authors.lastname: Qualls
authors.forename: Adrian F
authors.initials: AF
authors.lastname: Hernandez
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D058406:Cardiac Resynchronization Therapy / Q000009:adverse effects / Q000379:methods*; D057186:Comparative Effectiveness Research; D017147:Defibrillators, Implantable / Q000009:adverse effects; D004562:Electrocardiography; D006333:Heart Failure / Q000628:therapy*; D006801:Humans; D007239:Infections / Q000209:etiology; D010359:Patient Readmission; D057216:Propensity Score; D012189:Retrospective Studies; D012307:Risk Factors; D013318:Stroke Volume; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000628:therapy*