title: Female gender is associated with a better outcome after cardiac resynchronization therapy.
abstract: BACKGROUND
  Some studies have suggested that women respond differently to cardiac resynchronization therapy (CRT). We sought to determine whether female gender influences long-term clinical outcome, symptomatic response as well as echocardiographic response after CRT.
  
  
  RESULTS
  A total of 550 patients (age 70.4 ± 10.7 yrs [mean ± standard deviation]) were followed up for a maximum of 9.1 years (median: 36.2 months) after CRT-pacing (CRT-P) or CRT-defibrillation (CRT-D) device implantation. Outcome measure included mortality as well as unplanned hospitalizations for heart failure or major adverse cardiovascular events (MACE). Female gender predicted survival from cardiovascular death (hazard ratio [HR]: 0.52, P = 0.0051), death from any cause (HR: 0.52, P = 0.0022), the composite endpoints of cardiovascular death /heart failure hospitalizations (HR: 0.56, P = 0.0036) and death from any cause/hospitalizations for MACE (HR: 0.67, P = 0.0214). Female gender predicted death from pump failure (HR: 0.55, P = 0.0330) but not sudden cardiac death. Amongst the 322 patients with follow-up echocardiography, left ventricular (LV) reverse remodelling (≥ 15% reduction in LV end-systolic volume) was more pronounced in women (62% vs 44%, P = 0.0051). In multivariable Cox proportional hazards analyses, the association between female gender and cardiovascular survival was independent of age, LV ejection fraction, atrial rhythm, QRS duration, CRT device type, New York Heart Association (NYHA) class, and LV reverse remodelling (adjusted HR: 0.48, P = 0.0086). At one year, the symptomatic response rate (improvement by ≥ 1 NYHA classes or ≥ 25% increase in walking distance) was 78% for both women and men.
  
  
  CONCLUSIONS
  Female gender is independently associated with a lower mortality and morbidity after CRT.
authors.affiliation: Center for Cardiovascular Sciences, Queen Elizabeth Hospital, University of Birmingham, Birmingham, UK. cardiologists@hotmail.com
authors.forename: Francisco
authors.initials: F
authors.lastname: Leyva
authors.forename: Paul W X
authors.initials: PW
authors.lastname: Foley
authors.forename: Shajil
authors.initials: S
authors.lastname: Chalil
authors.forename: Nick
authors.initials: N
authors.lastname: Irwin
authors.forename: Russell E A
authors.initials: RE
authors.lastname: Smith
mesh_terms: D000368:Aged; D058406:Cardiac Resynchronization Therapy / Q000401:mortality*; D005260:Female; D006333:Heart Failure / Q000401:mortality* / Q000517:prevention & control*; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D018570:Risk Assessment; D012307:Risk Factors; D017678:Sex Distribution; D016019:Survival Analysis; D015996:Survival Rate; D016896:Treatment Outcome; D006113:United Kingdom / Q000453:epidemiology