title: Mid-term outcomes of triple-site vs. conventional cardiac resynchronization therapy: a preliminary study.
abstract: BACKGROUND
  The primary objectives of this study were to compare the implantation course of triple-site (double left-single right) and conventional cardiac resynchronization devices. The secondary target was to assess mid-term outcomes of both types of cardiac resynchronization therapy (CRT).
  
  
  METHODS
  Fifty-four patients with NYHA classes III-IV, left ventricular EF<or=35% and QRS>or=120 ms were included; 27 received triple-site pacemakers (TRIV group), 27 conventional CRT devices (BIV group). Procedural course, clinical data, QRS duration, echocardiographic parameters, peak oxygen consumption (VO2max) and 6-minute walking distance (6MWD) were screened for inter-group differences.
  
  
  RESULTS
  Procedure duration was higher in TRIV than in BIV group (197.6 vs. 137.6 min, P<0.001), fluoroscopy exposure and complication-rates were similar. After 3 months of CRT, triple-site pacing was associated with a more significant (P<0.05) NYHA class reduction (by 1.4 vs. 1.0 class, respectively), increase in VO(2) max (2.9 vs. 1.1 mL/kg/min) and 6MWD (98.7 vs. 51.6 m) than conventional CRT. A higher EF and more improved intraventricular synchrony were observed in the TRIV than in the BIV group. The response rate in the TRIV group was 96.3% vs. 62.9% in the conventional group (P=0.002). Triple-site stimulation was an independent predictor of response to CRT (adjusted odds ratio 26.4, P=0.01).
  
  
  CONCLUSIONS
  Triple-site resynchronization appears to be more beneficial than conventional CRT. Upgrade to triple-site CRT may be considered in non-responders to standard resynchronization.
authors.affiliation: First Department of Cardiology, Silesian Medical School, Silesian Center for Heart Disease, Zabrze, Poland. elfizab@poczta.onet.pl
authors.forename: Radosław
authors.initials: R
authors.lastname: Lenarczyk
authors.forename: Oskar
authors.initials: O
authors.lastname: Kowalski
authors.forename: Tomasz
authors.initials: T
authors.lastname: Kukulski
authors.forename: Patrycja
authors.initials: P
authors.lastname: Pruszkowska-Skrzep
authors.forename: Adam
authors.initials: A
authors.lastname: Sokal
authors.forename: Mariola
authors.initials: M
authors.lastname: Szulik
authors.forename: Teresa
authors.initials: T
authors.lastname: Zielińska
authors.forename: Jacek
authors.initials: J
authors.lastname: Kowalczyk
authors.forename: Sławomir
authors.initials: S
authors.lastname: Pluta
authors.forename: Beata
authors.initials: B
authors.lastname: Sredniawa
authors.forename: Agata
authors.initials: A
authors.lastname: Musialik-Łydka
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Kalarus
mesh_terms: D002304:Cardiac Pacing, Artificial / Q000379:methods*; D004452:Echocardiography; D017079:Exercise Tolerance; D005260:Female; D006333:Heart Failure / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology; D010138:Pacemaker, Artificial; D018579:Patient Selection; D012189:Retrospective Studies; D016896:Treatment Outcome; D016138:Walking / Q000502:physiology