title: Multipoint left ventricular pacing in a single coronary sinus branch improves mid-term echocardiographic and clinical response to cardiac resynchronization therapy.
abstract: BACKGROUND
  Cardiac resynchronization therapy (CRT) with multipoint left ventricular (LV) pacing in a single coronary sinus branch improves acute LV function. We hypothesized that multipoint pacing (MPP) can improve midterm echocardiographic and clinical response compared with conventional CRT.
  
  
  RESULTS
  Consecutive patients receiving a CRT implant (Unify Quadra MP™ or Quadra Assura MP™ CRT-D and Quartet™ LV lead, St. Jude Medical, Sylmar, CA, USA) were randomized to receive biventricular (BiV) pacing with either conventional LV pacing (CONV group) or MPP (MPP group). For each patient, an optimal pacing configuration for the assigned pacing mode was programmed based on intraoperative pressure-volume (PV) loop measurements. A clinical evaluation and transthoracic echocardiogram were performed before implant (BASELINE) and at 3 months postimplant and analyzed by a blinded observer. A reduction in end-systolic volume (ESV) of ≥15% relative to BASELINE was prospectively defined as response to CRT. Forty-four patients (NYHA Class III, EF 29 ± 6%, QRS duration 152 ± 17 milliseconds) were enrolled and randomized. One patient in the MPP group was lost to follow-up and excluded from further analysis. After 3 months, 11 of 22 (50%) CONV patients and 16 of 21 (76%) MPP patients were classified as responders. ESV reduction, EF increase, and NYHA class reduction relative to BASELINE were significantly greater in the MPP group than in the CONV group (ESV: -21.0 ± 13.9 vs. -12.6 ± 11.1%, P = 0.03; EF: +9.8 ± 5.1 vs. +2.0 ± 7.8 percentage points, P < 0.001; ΔNYHA: -1.05 ± 0.22 vs. -0.72 ± 0.46 functional classes, P = 0.006).
  
  
  CONCLUSIONS
  PV loop optimized BiV pacing with MPP resulted in an improved rate of response to CRT.
authors.affiliation: Department of Arrhythmology, Maria Cecilia Hospital, GVM Care & Research, Cotignola, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Pappone
authors.forename: Žarko
authors.initials: Ž
authors.lastname: Ćalović
authors.forename: Gabriele
authors.initials: G
authors.lastname: Vicedomini
authors.forename: Amarild
authors.initials: A
authors.lastname: Cuko
authors.forename: Luke C
authors.initials: LC
authors.lastname: McSpadden
authors.forename: Kyungmoo
authors.initials: K
authors.lastname: Ryu
authors.forename: Enrico
authors.initials: E
authors.lastname: Romano
authors.forename: Mario
authors.initials: M
authors.lastname: Baldi
authors.forename: Massimo
authors.initials: M
authors.lastname: Saviano
authors.forename: Alessia
authors.initials: A
authors.lastname: Pappone
authors.forename: Cristiano
authors.initials: C
authors.lastname: Ciaccio
authors.forename: Luigi
authors.initials: L
authors.lastname: Giannelli
authors.forename: Bogdan
authors.initials: B
authors.lastname: Ionescu
authors.forename: Andrea
authors.initials: A
authors.lastname: Petretta
authors.forename: Raffaele
authors.initials: R
authors.lastname: Vitale
authors.forename: Angelica
authors.initials: A
authors.lastname: Fundaliotis
authors.forename: Luigi
authors.initials: L
authors.lastname: Tavazzi
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Santinelli
mesh_terms: D000368:Aged; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D058406:Cardiac Resynchronization Therapy; D058409:Cardiac Resynchronization Therapy Devices; D054326:Coronary Sinus / Q000503:physiopathology*; D004867:Equipment Design; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000628:therapy*; D006352:Heart Ventricles / Q000503:physiopathology*; D006801:Humans; D007558:Italy; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D020127:Recovery of Function; D013318:Stroke Volume; D013997:Time Factors; D016896:Treatment Outcome; D014463:Ultrasonography; D016277:Ventricular Function, Left; D017725:Ventricular Pressure
keywords: CRT response; LV modeling; cardiac resynchronization therapy; heart failure; multipoint pacing; pressure-volume loops