title: Ambulatory respiratory rate trends identify patients at higher risk of worsening heart failure in implantable cardioverter defibrillator and biventricular device recipients: a novel ambulatory parameter to optimize heart failure management.
abstract: OBJECTIVE
  Respiratory distress is the primary driver for heart failure (HF) hospitalization. Implantable pacemakers and defibrillators are capable of monitoring respiratory rate (RR) in ambulatory HF patients. We investigated changes in RR prior to HF hospitalizations and its near-term risk stratification power.
  
  
  METHODS
  NOTICE-HF was an international multi-center study. Patients were implanted with an implantable cardioverter defibrillator or cardiac resynchronization therapy defibrillator, capable of trending daily maximum, median, and minimum RR (maxRR, medRR, minRR). RR from 120 patients with 9 months of follow-up was analyzed. One-tailed Student's t test was used to compare RR values prior to HF events to baseline defined as 4 weeks prior to the events. A Cox regression model was used to calculate the hazard ratios (HR) for the 30-day HF hospitalization risk based on RR values in the preceding month.
  
  
  RESULTS
  Daily maxRR, medRR, and minRR were significantly elevated prior to HF events compared to baseline (ΔmaxRR 1.8 ± 3.0; p = 0.02; ΔmedRR, 2.1 ± 2.8; p = 0.007; ΔminRR, 1.5 ± 2.1, p = 0.008). Risk of experiencing HF events within 30-days was increased if the standard deviation of medRR over the preceding month was above 1.0 br/min (HR = 12.3, 95 % confidence interval (CI) 2.57-59, p = 0.002). The risk remained high after adjusting for clinical variables that differed at enrollment.
  
  
  CONCLUSIONS
  Ambulatory daily respiratory rate trends may be a valuable addition to standard management for HF patients.
authors: German Heart Institute, Berlin, Germany, Stephan-goetze@web.de.
authors: Stephan
authors: S
authors: Goetze
authors: Yi
authors: Y
authors: Zhang
authors: Qi
authors: Q
authors: An
authors: Viktoria
authors: V
authors: Averina
authors: Pier
authors: P
authors: Lambiase
authors: Richard
authors: R
authors: Schilling
authors: Hans-Joachim
authors: HJ
authors: Trappe
authors: Siegmund
authors: S
authors: Winter
authors: Nicholas
authors: N
authors: Wold
authors: Ljubomir
authors: L
authors: Manola
authors: Dries
authors: D
authors: Kestens
mesh_terms: D058409:Cardiac Resynchronization Therapy Devices / Q000706:statistics & numerical data*; D017147:Defibrillators, Implantable / Q000706:statistics & numerical data*; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000175:diagnosis* / Q000453:epidemiology / Q000517:prevention & control*; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D038622:Internationality; D008297:Male; D018670:Monitoring, Ambulatory / Q000379:methods / Q000706:statistics & numerical data*; D015203:Reproducibility of Results; D056152:Respiratory Rate; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D016896:Treatment Outcome