title: Optimal Cardiac Resynchronization Therapy Pacing Rate in Non-Ischemic Heart Failure Patients: A Randomized Crossover Pilot Trial.
abstract: BACKGROUND
  The optimal pacing rate during cardiac resynchronization therapy (CRT) is unknown. Therefore, we investigated the impact of changing basal pacing frequencies on autonomic nerve function, cardiopulmonary exercise capacity and self-perceived quality of life (QoL).
  
  
  METHODS
  Twelve CRT patients with non-ischemic heart failure (NYHA class II-III) were enrolled in a randomized, double-blind, crossover trial, in which the basal pacing rate was set at DDD-60 and DDD-80 for 3 months (DDD-R for 2 patients). At baseline, 3 months and 6 months, we assessed sympathetic nerve activity by microneurography (MSNA), peak oxygen consumption (pVO2), N-terminal pro-brain natriuretic peptide (p-NT-proBNP), echocardiography and QoL.
  
  
  RESULTS
  DDD-80 pacing for 3 months increased the mean heart rate from 77.3 to 86.1 (p = 0.001) and reduced sympathetic activity compared to DDD-60 (51±14 bursts/100 cardiac cycles vs. 64±14 bursts/100 cardiac cycles, p<0.05). The mean pVO2 increased non-significantly from 15.6±6 mL/min/kg during DDD-60 to 16.7±6 mL/min/kg during DDD-80, and p-NT-proBNP remained unchanged. The QoL score indicated that DDD-60 was better tolerated.
  
  
  CONCLUSIONS
  In CRT patients with non-ischemic heart failure, 3 months of DDD-80 pacing decreased sympathetic outflow (burst incidence only) compared to DDD-60 pacing. However, Qol scores were better during the lower pacing rate. Further and larger scale investigations are indicated.
  
  
  BACKGROUND
  ClinicalTrials.gov NCT02258061.
authors.affiliation: The Heart Center, Department of Cardiology, Rigshospitalet Copenhagen University Hospital, Copenhagen, Denmark; Department of Clinical Physiology, Nuclear Medicine & PET, Rigshospitalet Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Adam Ali
authors.initials: AA
authors.lastname: Ghotbi
authors.affiliation: The Heart Center, Department of Cardiology, Rigshospitalet Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Mikael
authors.initials: M
authors.lastname: Sander
authors.affiliation: The Heart Center, Department of Cardiology, Rigshospitalet Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Lars
authors.initials: L
authors.lastname: Køber
authors.affiliation: The Heart Center, Department of Cardiology, Rigshospitalet Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Berit Th
authors.initials: BT
authors.lastname: Philbert
authors.affiliation: The Heart Center, Department of Cardiology, Rigshospitalet Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Finn
authors.initials: F
authors.lastname: Gustafsson
authors.affiliation: Department of Clinical Physiology, Nuclear Medicine & PET, Rigshospitalet Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Christoffer
authors.initials: C
authors.lastname: Hagemann
authors.affiliation: Department of Clinical Physiology, Nuclear Medicine & PET, Rigshospitalet Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Andreas
authors.initials: A
authors.lastname: Kjær
authors.affiliation: The Heart Center, Department of Cardiology, Rigshospitalet Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Peter K
authors.initials: PK
authors.lastname: Jacobsen
mesh_terms: D000368:Aged; D002138:Calibration; D058406:Cardiac Resynchronization Therapy / Q000009:adverse effects / Q000379:methods* / Q000592:standards*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D017079:Exercise Tolerance / Q000502:physiology; D005260:Female; D006333:Heart Failure / Q000097:blood / Q000503:physiopathology / Q000628:therapy*; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood; D010101:Oxygen Consumption / Q000502:physiology; D010446:Peptide Fragments / Q000097:blood; D010865:Pilot Projects; D011788:Quality of Life
chemical_list: D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain