title: Atrioventricular and ventricular-to-ventricular programming in patients with cardiac resynchronization therapy: results from ALTITUDE.
abstract: OBJECTIVE
  Cardiac resynchronization therapy (CRT) improves outcomes in patients with heart failure, yet response rates are variable. We sought to determine whether physician-specified CRT programming was associated with improved outcomes.
  
  
  METHODS
  Using data from the ALTITUDE remote follow-up cohort, we examined sensed atrioventricular (AV) and ventricular-to-ventricular (VV) programming and their associated outcomes in patients with de novo CRT from 2009-2010. Outcomes included arrhythmia burden, left ventricular (LV) pacing, and all-cause mortality at 4 years.
  
  
  RESULTS
  We identified 5709 patients with de novo CRT devices; at the time of implant, 34% (n = 1959) had entirely nominal settings programmed, 40% (n = 2294) had only AV timing adjusted, 11% (n = 604) had only VV timing adjusted, and 15% (n = 852) had both AV and VV adjusted from nominal programming. Suboptimal LV pacing (<95%) during follow-up was similar across groups; however, the proportion with atrial fibrillation (AF) burden >5% was lowest in the AV-only adjusted group (17.9%) and highest in the nominal (27.7%) and VV-only adjusted (28.3%) groups. Adjusted all-cause mortality was significantly higher among patients with non-nominal AV delay >120 vs. <120 ms (adjusted heart rate (HR) 1.28, p = 0.008) but similar when using the 180-ms cutoff (adjusted HR 1.13 for >180 vs. ≤180 ms, p = 0.4).
  
  
  CONCLUSIONS
  Nominal settings for de novo CRT implants are frequently altered, most commonly the AV delay. There is wide variability in reprogramming. Patients with nominal or AV-only adjustments appear to have favorable pacing and arrhythmia outcomes. Sensed AV delays less than 120 ms are associated with improved survival.
authors.affiliation: Electrophysiology Section, Duke University Medical Center, PO Box 17969, Durham, NC, 27715, USA. benjamin.steinberg@duke.edu.|Duke Clinical Research Institute, PO Box 17969, Durham, NC, 27715, USA. benjamin.steinberg@duke.edu.
authors.forename: Benjamin A
authors.initials: BA
authors.lastname: Steinberg
authors.affiliation: Boston Scientific, St. Paul, MN, USA. Scott.Wehrenberg@bsci.com.
authors.forename: Scott
authors.initials: S
authors.lastname: Wehrenberg
authors.affiliation: Electrophysiology Section, Duke University Medical Center, PO Box 17969, Durham, NC, 27715, USA.
authors.forename: Kevin P
authors.initials: KP
authors.lastname: Jackson
authors.affiliation: Division of Cardiovascular Disease, Mayo Clinic, Rochester, MN, USA. dhayes@mayo.edu.
authors.forename: David L
authors.initials: DL
authors.lastname: Hayes
authors.affiliation: Section of Electrophysiology and Pacing, Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland, OH, USA. varman@ccf.org.
authors.forename: Niraj
authors.initials: N
authors.lastname: Varma
authors.affiliation: Division of Cardiovascular Disease, Sanger Heart & Vascular Institute, Charlotte, NC, USA. powell.brian17@gmail.com.
authors.forename: Brian D
authors.initials: BD
authors.lastname: Powell
authors.affiliation: Division of Cardiovascular Disease, Intermountain Medical Center, Salt Lake City, UT, USA. johndaymd@gmail.com.
authors.forename: John D
authors.initials: JD
authors.lastname: Day
authors.affiliation: Electrophysiology Section, Duke University Medical Center, PO Box 17969, Durham, NC, 27715, USA.
authors.forename: Camille G
authors.initials: CG
authors.lastname: Frazier-Mills
authors.affiliation: Boston Scientific, St. Paul, MN, USA. kenneth.stein@bsci.com.
authors.forename: Kenneth M
authors.initials: KM
authors.lastname: Stein
authors.affiliation: Boston Scientific, St. Paul, MN, USA. Paul.Jones@bsci.com.
authors.forename: Paul W
authors.initials: PW
authors.lastname: Jones
authors.affiliation: Electrophysiology Section, Duke University Medical Center, PO Box 17969, Durham, NC, 27715, USA.|Duke Clinical Research Institute, PO Box 17969, Durham, NC, 27715, USA.
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Piccini
mesh_terms: D000368:Aged; D001145:Arrhythmias, Cardiac / Q000401:mortality* / Q000517:prevention & control*; D058406:Cardiac Resynchronization Therapy / Q000401:mortality*; D015897:Comorbidity; D003936:Diagnosis, Computer-Assisted / Q000379:methods / Q000401:mortality; D005260:Female; D006333:Heart Failure / Q000401:mortality* / Q000517:prevention & control*; D006339:Heart Rate; D006801:Humans; D015994:Incidence; D008297:Male; D015995:Prevalence; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012307:Risk Factors; D012680:Sensitivity and Specificity; D015996:Survival Rate; D013813:Therapy, Computer-Assisted / Q000379:methods / Q000706:statistics & numerical data*; D016896:Treatment Outcome; D014481:United States
keywords: Cardiac resynchronization therapy; Optimization; Outcomes; Programing