title: Three-dimensional echocardiographic optimization improves outcome in cardiac resynchronization therapy compared to ECG optimization: a randomized comparison.
abstract: OBJECTIVE
  There is little consensus on optimal atrioventricular (AV) and ventricular-to-ventricular (VV) intervals in cardiac resynchronization therapy (CRT). The aim of this study was to examine a novel combination of Doppler echocardiography (DE) and three-dimensional echocardiography (3DE) for individualized AV- and VV-interval optimization compared to conventional electrocardiogram (ECG) optimization.
  
  
  METHODS
  In this double-blind, randomized controlled trial, 77 patients (male: 57, age: 68 ± 10 years) with severely reduced ejection fraction (EF), New York Heart Association (NYHA) class III or IV, and wide QRS complex (>120 ms) have been included. Patients were randomized to either AV- and VV-interval optimization using DE and 3DE (group 1, n = 39) or ECG (group 2, n = 38). 3DE was performed in all patients for the evaluation of left ventricular (LV) dimensions, EF and systolic dyssynchrony index (SDI), and NYHA class obtained before CRT and after 3 months. Primary endpoint of the study was clinical response to CRT, defined as a reduction of NYHA class by ≥1 score. Secondary endpoints were change of EF, LV volumes, and SDI.
  
  
  RESULTS
  There were significantly more responders in group 1 (82%) than in group 2 (58%, P = 0.021). Similarly, group 1 showed a larger increase in EF (7.0 ± 6.0% vs 3.4 ± 5.6%, P = 0.015) and a more pronounced reduction of SDI (-4.5 ± 5.9% vs -1.5 ± 5.6%, P = 0.039) than group 2.
  
  
  CONCLUSIONS
  Compared with conventional ECG optimization, this novel echocardiographic optimization protocol resulted in a significantly higher response rate, improved LV systolic function, and may be used to select the optimal AV and VV intervals in CRT.
authors.affiliation: Klinik für Herz- und Kreislauferkrankungen, Deutsches Herzzentrum München, Technische Universität München, Munich, Germany.
authors.forename: Carolin
authors.initials: C
authors.lastname: Sonne
authors.forename: Lorenz
authors.initials: L
authors.lastname: Bott-Flugel
authors.forename: Simon
authors.initials: S
authors.lastname: Hauck
authors.forename: Martin
authors.initials: M
authors.lastname: Hadamitzky
authors.forename: Hasema
authors.initials: H
authors.lastname: Lesevic
authors.forename: Gabriele
authors.initials: G
authors.lastname: Demetz
authors.forename: Daniel
authors.initials: D
authors.lastname: Braun
authors.forename: Petra
authors.initials: P
authors.lastname: Wolf
authors.forename: Jörg
authors.initials: J
authors.lastname: Hausleiter
authors.forename: Albert
authors.initials: A
authors.lastname: Schömig
authors.forename: Christof
authors.initials: C
authors.lastname: Kolb
mesh_terms: D000368:Aged; D058406:Cardiac Resynchronization Therapy / Q000379:methods*; D004311:Double-Blind Method; D015150:Echocardiography, Doppler / Q000379:methods*; D019560:Echocardiography, Three-Dimensional / Q000379:methods*; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006333:Heart Failure / Q000175:diagnosis* / Q000517:prevention & control*; D006801:Humans; D008297:Male; D011379:Prognosis; D016896:Treatment Outcome
keywords: 3D echocardiography; cardiac resynchronization therapy; dyssynchrony; optimization