title: Inverse Relationship of Blood Pressure to Long-Term Outcomes and Benefit of Cardiac Resynchronization Therapy in Patients With Mild Heart Failure: A Multicenter Automatic Defibrillator Implantation Trial With Cardiac Resynchronization Therapy Long-Term Follow-Up Substudy.
abstract: BACKGROUND
  Previous studies have shown that low blood pressure is associated with increased mortality and heart failure (HF) in patients with left ventricular dysfunction. Cardiac resynchronization therapy (CRT) was shown to increase systolic blood pressure (SBP). Therefore, we hypothesized that treatment with CRT would provide incremental benefit in patients with lower SBP values.
  
  
  RESULTS
  The independent contribution of SBP to outcome was analyzed in 1267 patients with left bundle brunch block enrolled in Multicenter Automatic Defibrillator Implantation Trial With Cardiac Resynchronization Therapy (MADIT-CRT). SBP was assessed as continuous measures and further categorized into approximate quintiles. The risk of long-term HF or death and CRT with defibrillator versus implantable cardioverter defibrillator benefit was assessed in multivariate Cox proportional hazards regression models. Multivariate analysis showed that in the implantable cardioverter defibrillator arm, each 10-mm Hg decrement of SBP was independently associated with a significant 21% (P<0.001) increased risk for HF or death, and patients with lower quintile SBP (<110 mm Hg) experienced a corresponding >2-fold risk-increase. CRT with defibrillator provided the greatest HF or mortality risk reduction in patients with SBP<110 mm Hg hazard ratio of 0.34, P<0.001, when compared with hazard ratio of 0.52, P<0.001, in those with 110>SBP≥136 mm Hg and hazard ratio of 0.94, P=0.808, with SBP>136 mm Hg (P for trend=0.001).
  
  
  CONCLUSIONS
  In patients with mild HF, prolonged QRS, and left bundle brunch block, low SBP is related to higher risk of mortality or HF with implantable cardioverter defibrillator therapy alone. Treatment with CRT is associated with incremental clinical benefits in patients with lower baseline SBP values.
  
  
  BACKGROUND
  URL: http://www.clinicaltrials.gov. Unique identifier: NCT00180271.
authors.affiliation: From the Heart Research Follow-Up Program, Division of Cardiology, Department of Medicine, University of Rochester Medical Center, NY. yitschak.biton@heart.rochester.edu.
authors.forename: Yitschak
authors.initials: Y
authors.lastname: Biton
authors.affiliation: From the Heart Research Follow-Up Program, Division of Cardiology, Department of Medicine, University of Rochester Medical Center, NY.
authors.forename: Arthur J
authors.initials: AJ
authors.lastname: Moss
authors.affiliation: From the Heart Research Follow-Up Program, Division of Cardiology, Department of Medicine, University of Rochester Medical Center, NY.
authors.forename: Valentina
authors.initials: V
authors.lastname: Kutyifa
authors.affiliation: From the Heart Research Follow-Up Program, Division of Cardiology, Department of Medicine, University of Rochester Medical Center, NY.
authors.forename: Andrew
authors.initials: A
authors.lastname: Mathias
authors.affiliation: From the Heart Research Follow-Up Program, Division of Cardiology, Department of Medicine, University of Rochester Medical Center, NY.
authors.forename: Saadia
authors.initials: S
authors.lastname: Sherazi
authors.affiliation: From the Heart Research Follow-Up Program, Division of Cardiology, Department of Medicine, University of Rochester Medical Center, NY.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Zareba
authors.affiliation: From the Heart Research Follow-Up Program, Division of Cardiology, Department of Medicine, University of Rochester Medical Center, NY.
authors.forename: Scott
authors.initials: S
authors.lastname: McNitt
authors.affiliation: From the Heart Research Follow-Up Program, Division of Cardiology, Department of Medicine, University of Rochester Medical Center, NY.
authors.forename: Bronislava
authors.initials: B
authors.lastname: Polonsky
authors.affiliation: From the Heart Research Follow-Up Program, Division of Cardiology, Department of Medicine, University of Rochester Medical Center, NY.
authors.forename: Alon
authors.initials: A
authors.lastname: Barsheshet
authors.affiliation: From the Heart Research Follow-Up Program, Division of Cardiology, Department of Medicine, University of Rochester Medical Center, NY.
authors.forename: Mary W
authors.initials: MW
authors.lastname: Brown
authors.affiliation: From the Heart Research Follow-Up Program, Division of Cardiology, Department of Medicine, University of Rochester Medical Center, NY.
authors.forename: Ilan
authors.initials: I
authors.lastname: Goldenberg
mesh_terms: D000368:Aged; D001794:Blood Pressure / Q000502:physiology*; D058406:Cardiac Resynchronization Therapy / Q000379:methods*; D017147:Defibrillators, Implantable; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends; D013997:Time Factors; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology
keywords: blood pressure; bundle-branch block; cardiac resynchronization therapy; cardioverter-defibrillators, implantable; heart failure; mortality