title: Electrical optimization of cardiac resynchronization in chronic heart failure is associated with improved clinical long-term outcome.
abstract: BACKGROUND
  Cardiac resynchronization therapy (CRT) is an established treatment option for symptomatic chronic heart failure (CHF) patients with pharmacological baseline therapy, but not all patients benefit from device therapy. One reason for this may be inadequate device settings. In real-world practice, echocardiographic evaluation of atrioventricular (AV) delay is not performed in a high proportion of patients, as the effect of electrical optimization of CRT is an issue open for investigation.
  
  
  METHODS
  We performed a retrospective observational study analysing the effect of AV-interval evaluation with echocardiography on long-term [32 (23?43) months] clinical outcome in 205 CHF patients. A stepwise Cox regression model including a co-morbidity score, failed AV-interval evaluation, satisfactory device function after the first implantation attempt, failure to reach 100% of the recommended renin-angiotensin system inhibitor and beta-blocker dose at follow-up and CRT device implantation compared with CRT in combination with an implanted cardioverter defibrillator (ICD) was applied.
  
  
  RESULTS
  In the total study cohort, 124 (60.5%) patients had reached the primary combined endpoint death or cardiac hospitalization and 59 (28.8%) had died. Cox regression analysis revealed that failed AV-interval evaluation [HR = 1.72 (1.19-2.49), P = 0.004] non-optimized CHF pharmacotherapy dosages [HR = 2.12 (1.32-3.42), P = 0.002], the presence of a CRT/ICD combination device [HR = 1.87 (1.28-2.71), P = 0.001] and satisfactory device function after the first implantation attempt [HR = 0.44 (0.25-0.77), P = 0.004] were associated with the primary endpoint.
  
  
  CONCLUSIONS
  Echocardiographic evaluation of the AV-interval in patients with CRT was independently associated with improved clinical outcome, impacting on daily clinical practice of HF patient care.
authors.affiliation: Department of Internal Medicine II, Division of Cardiology, Medical University of Vienna, Vienna, Austria.
authors.forename: Christopher
authors.initials: C
authors.lastname: Adlbrecht
authors.forename: Martin
authors.initials: M
authors.lastname: Hülsmann
authors.forename: Marianne
authors.initials: M
authors.lastname: Gwechenberger
authors.forename: Senta
authors.initials: S
authors.lastname: Graf
authors.forename: Franz
authors.initials: F
authors.lastname: Wiesbauer
authors.forename: Guido
authors.initials: G
authors.lastname: Strunk
authors.forename: Cesar
authors.initials: C
authors.lastname: Khazen
authors.forename: Isabella
authors.initials: I
authors.lastname: Brodnjak
authors.forename: Stephanie
authors.initials: S
authors.lastname: Neuhold
authors.forename: Thomas
authors.initials: T
authors.lastname: Binder
authors.forename: Gerald
authors.initials: G
authors.lastname: Maurer
authors.forename: Richard
authors.initials: R
authors.lastname: Pacher
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage; D000368:Aged; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D002908:Chronic Disease; D015331:Cohort Studies; D004452:Echocardiography; D005260:Female; D006333:Heart Failure / Q000401:mortality / Q000628:therapy*; D017052:Hospital Mortality; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D012044:Regression Analysis; D012189:Retrospective Studies; D016019:Survival Analysis
chemical_list: D000319:Adrenergic beta-Antagonists