title: Is there a heart rate paradox in acute heart failure?
abstract: BACKGROUND
  Higher heart rate predicts higher mortality in chronic heart failure (HF). We studied the prognostic impact of admission heart rate in acute HF and analysed the importance of its change during hospitalization.
  
  
  METHODS
  Acute HF patients were studied. Endpoint was all-cause death. Patients were followed-up for 12 months from hospital admission. Cox-regression analysis was used to study the association of heart rate (both as a continuous and as a categorical variable) with mortality. Analysis was stratified according to admission rhythm and to systolic dysfunction. Multivariate models were built. Patients surviving hospitalization were additionally cross-classified attending to admission and discharge heart rates – cut-offs: 100 and 80 beats per minute (bpm), respectively.
  
  
  RESULTS
  We analysed 564 patients. Median age was 78 years and median admission heart rate 87 bpm. In a 12-month period 205 patients died, 23 in-hospital. Mortality increased steadily with heart rate decrease. Patients with heart rate ≥ 100 bpm had a multivariate-adjusted HR of 12-month death of 0.57 (95%CI: 0.39-0.81), and the HR was 0.92 (0.85-0.98) per 10 bpm increase in heart rate. Association of heart rate with mortality was stronger in patients in sinus rhythm (SR) and in those with systolic dysfunction. Eighty-seven patients had admission heart rate ≥ 100 and discharge heart rate < 80 bpm. In them, death rate was 14.9%; in the remaining patients it was 37.7%.
  
  
  CONCLUSIONS
  Higher admission heart rate predicted survival advantage in acute HF. Patients presenting with tachycardia and discharged with a controlled heart rate had better outcome than those admitted non-tachycardic or discharged with a non-controlled heart rate.
authors.affiliation: Serviço de Medicina Interna, Centro Hospitalar São João, Porto, Portugal. Electronic address: pamlourenco@yahoo.com.
authors.forename: Patrícia
authors.initials: P
authors.lastname: Lourenço
authors.affiliation: Serviço de Medicina Interna, Centro Hospitalar São João, Porto, Portugal.
authors.forename: Ana
authors.initials: A
authors.lastname: Ribeiro
authors.affiliation: Serviço de Endocrinologia, Diabetes e Metabolismo, Centro Hospitalar São João, Porto, Portugal.
authors.forename: Filipe M
authors.initials: FM
authors.lastname: Cunha
authors.affiliation: Serviço de Medicina Interna, Centro Hospitalar São João, Porto, Portugal; Faculdade de Medicina da Universidade do Porto; Unidade I&D Cardiovascular do Porto, Portugal.
authors.forename: Mariana
authors.initials: M
authors.lastname: Pintalhão
authors.affiliation: Serviço de Medicina Interna, Centro Hospitalar São João, Porto, Portugal.
authors.forename: Pedro
authors.initials: P
authors.lastname: Marques
authors.affiliation: Serviço de Medicina Interna, Centro Hospitalar São João, Porto, Portugal.
authors.forename: Francisco
authors.initials: F
authors.lastname: Cunha
authors.affiliation: Serviço de Medicina Interna, Centro Hospitalar São João, Porto, Portugal.
authors.forename: Sérgio
authors.initials: S
authors.lastname: Silva
authors.affiliation: Serviço de Medicina Interna, Centro Hospitalar São João, Porto, Portugal; Faculdade de Medicina da Universidade do Porto; Unidade I&D Cardiovascular do Porto, Portugal.
authors.forename: Paulo
authors.initials: P
authors.lastname: Bettencourt
mesh_terms: D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D002423:Cause of Death / Q000639:trends; D005260:Female; D006333:Heart Failure / Q000401:mortality / Q000503:physiopathology*; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D011174:Portugal / Q000453:epidemiology; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends
keywords: Acute heart failure;; Heart rate; Heart rhythm; Paradox; Prognosis