title: Multipoint pacing via a quadripolar left-ventricular lead: preliminary results from the Italian registry on multipoint left-ventricular pacing in cardiac resynchronization therapy (IRON-MPP).
abstract: OBJECTIVE
  This registry was created to describe the experience of 76 Italian centres with a large cohort of recipients of multipoint pacing (MPP) capable cardiac resynchronization therapy (CRT) devices.
  
  
  RESULTS
  A total of 507 patients in whom these devices had been successfully implanted were enrolled between August 2013 and May 2015. We analysed: (i) current clinical practices for the management of such patients, and (ii) the impact of MPP on heart failure clinical composite response and on the absolute change in ejection fraction (EF) at 6 months. Multipoint pacing was programmed to 'ON' in 46% of patients before discharge. Methods of optimizing MPP programming were most commonly based on either the greatest narrowing of the QRS complex (38%) or the electrical delays between the electrodes (34%). Clinical and echocardiographic follow-up data were evaluated in 232 patients. These patients were divided into two groups according to whether MPP was programmed to 'ON' (n = 94) or 'OFF' (n = 138) at the time of discharge. At 6 months, EF was significantly higher in the MPP group than in the biventricular-pacing group (39.1 ± 9.6 vs. 34.7 ± 7.6%; P < 0.001). Even after adjustments, early MPP activation remained an independent predictor of absolute increase in LVEF of ≥5% (odds ratio 2.5; P = 0.001). At 6 months, an improvement in clinical composite score was recorded in a greater proportion of patients with MPP-ON than in controls (56 vs. 38%; P = 0.009). On comparing optimal MPP and conventional vectors, QRS was also seen to have decreased significantly (P < 0.001).
  
  
  CONCLUSIONS
  This study provides information that is essential in order to deal with the expected increase in the number of patients receiving MPP devices in the coming years. The results revealed different practices among centres, and establishing the optimal programming that can maximize the benefit of MPP remains a challenging issue. Compared with conventional CRT, MPP improved clinical status and resulted in an additional increase in EF.
  
  
  BACKGROUND
  http://www.clinicaltrial.gov/. Unique identifier: NCT02606071.
authors.affiliation: Policlinico Universitario Tor Vergata, Viale Oxford, 81, Rome 00133, Italy.
authors.forename: Giovanni B
authors.initials: GB
authors.lastname: Forleo
authors.affiliation: Policlinico Universitario Tor Vergata, Viale Oxford, 81, Rome 00133, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Santini
authors.affiliation: Ospedale Maria Vittoria, Torino, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Giammaria
authors.affiliation: Ospedale Casa Sollievo Della Sofferenza, S.Giovanni Rotondo, Italy.
authors.forename: Domenico
authors.initials: D
authors.lastname: Potenza
authors.affiliation: Ospedali Civili di Brescia, Brescia, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Curnis
authors.affiliation: Policlinico Universitario Campus Bio-Medico, Rome, Italy.
authors.forename: Vito
authors.initials: V
authors.lastname: Calabrese
authors.affiliation: Policlinico Universitario Campus Bio-Medico, Rome, Italy.
authors.forename: Danilo
authors.initials: D
authors.lastname: Ricciardi
authors.affiliation: Ospedale di Venere, Bari, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: D'agostino
authors.affiliation: Ospedale S. Donato, Arezzo, Italy.
authors.forename: Pasquale
authors.initials: P
authors.lastname: Notarstefano
authors.affiliation: Policlinico Universitario Tor Vergata, Viale Oxford, 81, Rome 00133, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Ribatti
authors.affiliation: Azienda Ospedaliera Universitaria Verona, Verona, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Morani
authors.affiliation: Policlinico S. Ambrogio, Milan, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Mantica
authors.affiliation: Albert Einstein College of Medicine at Montefiore Hospital, New York, NY, USA.|Department of Cardiology, University of Foggia, Foggia, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Di Biase
authors.affiliation: Azienda Ospedaliera Universitaria, Padova, Italy.
authors.forename: Emanuele
authors.initials: E
authors.lastname: Bertaglia
authors.affiliation: Policlinico Casilino, Roma, Italy.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Calò
authors.affiliation: Azienda Ospedaliera Universitaria, Padova, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Zanon
mesh_terms: D000200:Action Potentials; D000368:Aged; D058406:Cardiac Resynchronization Therapy / Q000009:adverse effects; D058409:Cardiac Resynchronization Therapy Devices; D016009:Chi-Square Distribution; D004867:Equipment Design; D005260:Female; D054625:Healthcare Disparities; D006333:Heart Failure / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D006339:Heart Rate; D006801:Humans; D007558:Italy; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D011446:Prospective Studies; D020127:Recovery of Function; D012042:Registries; D012307:Risk Factors; D013318:Stroke Volume; D013997:Time Factors; D016896:Treatment Outcome; D016277:Ventricular Function, Left
keywords: Cardiac resynchronization therapy; Heart failure; Left ventricular pacing configurations; MPP; Multipoint pacing; Optimization