title: Contractility sensor-guided optimization of cardiac resynchronization therapy: results from the RESPOND-CRT trial.
abstract: OBJECTIVE
  Although cardiac resynchronization therapy (CRT) is effective in patients with systolic heart failure (HF) and a wide QRS interval, a substantial proportion of patients remain non-responsive. The SonR contractility sensor embedded in the right atrial lead enables individualized automatic optimization of the atrioventricular (AV) and interventricular (VV) timings. The RESPOND-CRT study investigated the safety and efficacy of the contractility sensor system in HF patients undergoing CRT.
  
  
  RESULTS
  RESPOND-CRT was a prospective, randomized, double-blinded, multicentre, non-inferiority trial. Patients were randomized (2:1, respectively) to receive weekly, automatic CRT optimization with SonR vs. an Echo-guided optimization of AV and VV timings. The primary efficacy endpoint was the rate of clinical responders (patients alive, without adjudicated HF-related events, with improvement in New York Heart Association class or quality of life), at 12 months. The study randomized 998 patients. Responder rates were 75.0% in the SonR arm and 70.4% in the Echo arm (mean difference, 4.6%; 95% CI, -1.4% to 10.6%; P < 0.001 for non-inferiority margin -10.0%) (Table 2). At an overall mean follow-up of 548 ± 190 days SonR was associated with a 35% risk reduction in HF hospitalization (hazard ratio, 0.65; 95% CI, 0.46-0.92; log-rank P = 0.01).
  
  
  CONCLUSIONS
  Automatic AV and VV optimization using the contractility sensor was safe and as effective as Echo-guided AV and VV optimization in increasing response to CRT.
  
  
  BACKGROUND
  NCT01534234.
authors.affiliation: Cardiovascular Institute, Hospital Clinic, University of Barcelona, Barcelona, Spain.
authors.forename: Josep
authors.initials: J
authors.lastname: Brugada
authors.affiliation: Isala klinieken Zwolle, Zwolle, The Netherlands.
authors.forename: Peter Paul
authors.initials: PP
authors.lastname: Delnoy
authors.affiliation: Coburg Hospital, Coburg, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Brachmann
authors.affiliation: University of Oklahoma, Oklahoma City, OK, USA.
authors.forename: Dwight
authors.initials: D
authors.lastname: Reynolds
authors.affiliation: University of Florence, Italy and IRCCS Multimedica, Milan, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Padeletti
authors.affiliation: Herz- und Diabeteszentrum, Bad Oeynhausen, Germany.
authors.forename: Georg
authors.initials: G
authors.lastname: Noelker
authors.affiliation: Piedmont Heart Institute, Atlanta, GA, USA.
authors.forename: Charan
authors.initials: C
authors.lastname: Kantipudi
authors.affiliation: Hospital Universitario Central de Asturias, Oviedo, Spain.
authors.forename: José Manuel
authors.initials: JM
authors.lastname: Rubin Lopez
authors.affiliation: Department of Internal Medicine III, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Dichtl
authors.affiliation: LivaNova Cardiac Rhythm Management, Saluggia, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Borri-Brunetto
authors.affiliation: LivaNova, Clamart, France.
authors.forename: Luc
authors.initials: L
authors.lastname: Verhees
authors.affiliation: University Hospital of Bordeaux, Pessac, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Ritter
authors.affiliation: Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Jagmeet P
authors.initials: JP
authors.lastname: Singh
mesh_terms: D000368:Aged; D058406:Cardiac Resynchronization Therapy / Q000379:methods; D058409:Cardiac Resynchronization Therapy Devices; D004311:Double-Blind Method; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D054143:Heart Failure, Systolic / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008297:Male; D009200:Myocardial Contraction / Q000502:physiology; D011446:Prospective Studies; D013318:Stroke Volume / Q000502:physiology; D016896:Treatment Outcome
keywords: AV and VV optimization; Adaptive CRT; CRT optimization; Cardiac contractility; HF hospitalization; RESPOND; SonR