title: Repeated heart rate measurement and cardiovascular outcomes in left ventricular systolic dysfunction.
abstract: BACKGROUND
  Elevated resting heart rate is associated with increased cardiovascular risk, particularly in patients with left ventricular systolic dysfunction. Heart rate is not monitored routinely in these patients. We hypothesized that routine monitoring of heart rate would increase its prognostic value in patients with left ventricular systolic dysfunction.
  
  
  METHODS
  We analyzed the relationship between heart rate measurements and a range of adverse cardiovascular outcomes, including hospitalization for worsening heart failure, in the pooled placebo-treated patients from the morBidity-mortality EvAlUaTion of the If inhibitor ivabradine in patients with coronary disease and left ventricULar dysfunction (BEAUTIFUL) trial and Systolic Heart failure treatment with the If inhibitor ivabradine (SHIFT) Trial, using standard and time-varying covariate Cox proportional hazards models. By adjusting for other prognostic factors, models were fitted for baseline heart rate alone or for time-updated heart rate (latest heart rate) alone or corrected for baseline heart rate or for immediate previous time-updated heart rate.
  
  
  RESULTS
  Baseline heart rate was strongly associated with all outcomes apart from hospitalization for myocardial infarction. Time-updated heart rate increased the strengths of associations for all outcomes. Adjustment for baseline heart rate or immediate previous time-updated heart rate modestly reduced the prognostic importance of time-updated heart rate. For hospitalization for worsening heart failure, each 5 beats/min increase in baseline heart rate and time-updated heart rate was associated with a 15% (95% confidence interval, 12-18) and 22% (confidence interval, 19-40) increase in risk, respectively. Even after correction, the prognostic value of time-updated heart rate remained greater.
  
  
  CONCLUSIONS
  In patients with left ventricular systolic dysfunction, time-updated heart rate is more strongly related with adverse cardiovascular outcomes than baseline heart rate. Heart rate should be measured to assess cardiovascular risk at all assessments of patients with left ventricular systolic dysfunction.
authors.affiliation: Robertson Centre for Biostatistics, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Victoria
authors.initials: V
authors.lastname: Hamill
authors.affiliation: Robertson Centre for Biostatistics, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Ian
authors.initials: I
authors.lastname: Ford
authors.affiliation: National Heart and Lung Institute, Imperial College and Institute of Cardiovascular Medicine and Science and Royal Brompton Hospital, London, United Kingdom.
authors.forename: Kim
authors.initials: K
authors.lastname: Fox
authors.affiliation: Universitätsklinikums des Saarlandes, Klinik für Innere Medizin III, Homburg/Saar, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Böhm
authors.affiliation: Division of Cardiovascular Medicine, the Howard Gilman Institute for Heart Valve Disease and the Ronald and Jean Schiavone Institute for Cardiovascular Translational Research, State University of New York Downstate Medical Center, Brooklyn and New York.
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Borer
authors.affiliation: Department of Cardiology and LTTA Centre, University Hospital of Ferrara and Maria Cecilia Hospital, GVM, Ferrara, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Ferrari
authors.affiliation: Department of Cardiology, University Pierre et Marie Curie Paris VI, La Pitié-Salpêtrière Hôpital and Institute of Cardio Metabolism ICAN, Paris, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Komajda
authors.affiliation: National Heart and Lung Institute, Imperial College and Institute of Cardiovascular Medicine and Science and Royal Brompton Hospital, London, United Kingdom; DHU FIRE, Hôpital Bichat, Assistance Publique-Hôpitaux de Paris, Universite Paris-Diderot, Paris, France; INSERM U-1148, Paris, France.
authors.forename: Philippe Gabriel
authors.initials: PG
authors.lastname: Steg
authors.affiliation: Maria Cecilia Hospital-GVM Care and Research, Ettore Sansavini Health Science Foundation, Cotignola, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Tavazzi
authors.affiliation: Medical University of Silesia, Katowice, Poland.
authors.forename: Michal
authors.initials: M
authors.lastname: Tendera
authors.affiliation: National Heart and Lung Institute, Imperial College and Institute of Cardiovascular Medicine and Science and Royal Brompton Hospital, London, United Kingdom; Department of Molecular and Clinical Medicine, University of Gothenburg, Gothenburg, Sweden. Electronic address: karl.swedberg@gu.se.
authors.forename: Karl
authors.initials: K
authors.lastname: Swedberg
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006333:Heart Failure / Q000175:diagnosis / Q000209:etiology / Q000401:mortality; D006339:Heart Rate; D006760:Hospitalization; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis / Q000209:etiology / Q000401:mortality; D011379:Prognosis; D016016:Proportional Hazards Models; D013997:Time Factors; D018487:Ventricular Dysfunction, Left / Q000150:complications / Q000401:mortality / Q000503:physiopathology*
keywords: BEAUTIFUL; Heart rate; Left ventricular systolic dysfunction; Prognosis; SHIFT