title: Metabolic syndrome is associated with different clinical outcome after cardiac resynchronization therapy in patients with ischemic and non-ischemic cardiomyopathy.
abstract: BACKGROUND
  Although association of metabolic syndrome (MS) and ischemic heart disease is strongly established, it is not known whether presence of MS may differently influence clinical responses to cardiac resynchronization therapy (CRT). The aim of this study was to evaluate the associations between obesity and metabolic features and the clinical outcome after cardiac resynchronization with defibrillator therapy (CRT-D), compared to an implantable cardioverter defibrillator (ICD).
  
  
  METHODS
  The risk of heart failure (HF) or death and death alone was evaluated in 829 non-obese patients, 156 obese patients without MS, and 277 obese patients with MS (all with left bundle branch block), who were enrolled in the Multicenter Automatic Defibrillator Implanta-tion Trial with Cardiac Resynchronization Therapy (MADIT-CRT).
  
  
  RESULTS
  Obese patients with MS (HR 0.50, 95% CI 0.32-0.77, p = 0.002), obese patients without MS (HR 0.57, 95% CI 0.30-1.06, p = 0.077), and non-obese patients (HR 0.48, 95% CI 0.37-0.62, p < 0.001) had a similar risk reduction of HF/death in response to CRT-D therapy when compared to ICD patients. However, among those with non-ischemic cardiomyo-pathy, obese patients with MS experienced a 90% reduction for HF/death (HR 0.11, 95% CI 0.04-0.32, p < 0.001), whereas obese patients without MS had no reduction (HR 0.98, 95% CI 0.48-1.98, p = 0.951; interaction p < 0.001). The reverse was observed in ischemic car-diomyopathy patients: obese patients with MS had no reduction in the risk of HF/death (HR 0.80, 95% CI 0.48-1.34, p = 0.402), while obese patients without MS showed a significant reduction in the risk of events (HR 0.15, 95% CI 0.04-0.65, p = 0.011; interaction p = 0.036). Similar trends were observed for the endpoint of death.
  
  
  CONCLUSIONS
  Presence of MS differentiates the response to CRT in obese patients with is-chemic and non-ischemic etiology for HF.
authors.affiliation: University of Rochester Medical Center, Rochester, New York, United States. barbara.szepietowska@heart.rochester.edu.
authors.forename: Barbara
authors.initials: B
authors.lastname: Szepietowska
authors.forename: Scott
authors.initials: S
authors.lastname: McNitt
authors.forename: Bronislava
authors.initials: B
authors.lastname: Polonsky
authors.forename: Saadia
authors.initials: S
authors.lastname: Sherazi
authors.forename: Yitschak
authors.initials: Y
authors.lastname: Biton
authors.forename: Valentina
authors.initials: V
authors.lastname: Kutyifa
authors.forename: Mehmet K
authors.initials: MK
authors.lastname: Aktas
authors.forename: Arthur J
authors.initials: AJ
authors.lastname: Moss
authors.forename: Wojciech
authors.initials: W
authors.lastname: Zareba
mesh_terms: D000328:Adult; D000368:Aged; D058406:Cardiac Resynchronization Therapy; D009202:Cardiomyopathies / Q000150:complications / Q000453:epidemiology / Q000628:therapy*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D024821:Metabolic Syndrome / Q000150:complications* / Q000453:epidemiology; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000150:complications / Q000453:epidemiology / Q000628:therapy*; D009765:Obesity / Q000150:complications* / Q000453:epidemiology; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology; D055815:Young Adult
keywords: cardiac resynchronization therapy; clinical outcome; heart failure; implantable cardioverter defibrillator; metabolic syndrome; obesity