title: Right ventricular function, pulmonary pressure estimation, and clinical outcomes in cardiac resynchronization therapy.
abstract: BACKGROUND
  Right ventricular function (RVF) is an important determinant of outcome in patients with heart failure, and those with severe RV dysfunction have worse outcome after cardiac resynchronization therapy (CRT). We used data from the Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy (MADIT-CRT) Trial to determine whether therapy with CRT is influenced by or affects RV function and to define the relationship between RV function and outcomes.
  
  
  RESULTS
  A total of 1820 patients were randomly assigned to CRT plus implantable cardioverter defibrillator or implantable cardioverter defibrillator-only in a 3:2 ratio. We assessed RVF as RV fractional area change by echocardiography at baseline and after 1 year of therapy (n=1511 and 1273, respectively). The median RV fractional area change was 41%, with 10.9% of patients <35% at baseline. Baseline RVF did not modify the treatment effect of CRT on the primary outcome (interaction P=0.19). Randomization to CRT-implantable cardioverter defibrillator was associated with a greater improvement in RVF (ΔRV fractional area change 8.1% versus 5.4%; P<0.001), and improvement in RVF was related to subsequent outcomes. Every 5-point increase in RV fractional area change was associated with a 22% reduction in event rates (hazard ratio, 0.78; 95% confidence interval, 0.66-0.92; P=0.003), although this was not independent of the concurrent improvement in left ventricular function. Baseline tricuspid regurgitant velocity, a measure of pulmonary systolic pressure, was predictive of events in a multivariate analysis (hazard ratio, 1.86; 95% confidence interval, 1.24-2.8; P=0.003).
  
  
  CONCLUSIONS
  In this population with mild heart failure symptoms, CRT was associated with improvement in RVF, which improved in parallel with improvement in left ventricular function. Patients with the best RVF at 1 year demonstrated the lowest subsequent event rates.
  
  
  BACKGROUND
  URL: http://www.clinicaltrials.gov. Unique identifier: NCT01294449.
authors.affiliation: Department of Cardiology, Brigham and Women's Hospital, Boston, MA 02115, USA.
authors.forename: Patricia
authors.initials: P
authors.lastname: Campbell
authors.forename: Madoka
authors.initials: M
authors.lastname: Takeuchi
authors.forename: Mikhail
authors.initials: M
authors.lastname: Bourgoun
authors.forename: Amil
authors.initials: A
authors.lastname: Shah
authors.forename: Elyse
authors.initials: E
authors.lastname: Foster
authors.forename: Mary W
authors.initials: MW
authors.lastname: Brown
authors.forename: Ilan
authors.initials: I
authors.lastname: Goldenberg
authors.forename: David T
authors.initials: DT
authors.lastname: Huang
authors.forename: Scott
authors.initials: S
authors.lastname: McNitt
authors.forename: W Jackson
authors.initials: WJ
authors.lastname: Hall
authors.forename: Arthur
authors.initials: A
authors.lastname: Moss
authors.forename: Marc A
authors.initials: MA
authors.lastname: Pfeffer
authors.forename: Scott D
authors.initials: SD
authors.lastname: Solomon
mesh_terms: D000368:Aged; D058406:Cardiac Resynchronization Therapy; D003131:Combined Modality Therapy; D017147:Defibrillators, Implantable; D005260:Female; D006333:Heart Failure / Q000503:physiopathology* / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D016016:Proportional Hazards Models; D016896:Treatment Outcome; D014463:Ultrasonography; D018497:Ventricular Dysfunction, Right / Q000000981:diagnostic imaging; D016277:Ventricular Function, Left; D016278:Ventricular Function, Right
keywords: cardiac resynchronization therapy; heart failure; right ventricle