title: Short-term hemodynamic and neuroendocrine effects of pimobendan and benazapril in dogs with myxomatous mitral valve disease and congestive heart failure.
abstract: BACKGROUND
  Pimobendan and benazepril are frequently used with diuretics to treat dogs in congestive heart failure (CHF) caused by myxomatous mitral valve disease (MMVD).
  
  
  OBJECTIVE
  To compare the short-term effects of pimobendan versus benazepril on pump function, heart size, and neuroendocrine profile in dogs with CHF caused by MMVD.
  
  
  METHODS
  Sixteen client-owned dogs.
  
  
  METHODS
  Seven-day prospective single-blinded study of dogs stabilized on furosemide monotherapy, randomized to pimobendan (0.4-0.6 mg/kg/day) or benazepril (0.25-1.0 mg/kg/day). Dogs had first-pass radionuclide angiocardiography, and heart size was measured by radiography and echocardiography. Circulating neuroendocrine hormones were measured.
  
  
  RESULTS
  Baseline variables did not differ between treatment groups. Greater decreases in the pimobendan than in the benazepril group were found for heart rate (P = .001), heart rate-normalized pulmonary transit time (P = .02), left atrial size (P = .03), and systolic and diastolic left ventricular diameters (P < .001 and P = .03, respectively) and volumes (P < .001 and P = .02, respectively), whereas ejection fraction increased more (P = .02) in the pimobendan group. Of the neuroendocrine hormones, only N-terminal proatrial natriuretic peptide (NT-ProANP) differed (P = .04) between groups. Within groups, plasma aldosterone increased (P = .01), and NT-proANP (P = .01) and NT-proB-type (P = .02) natriuretic peptide decreased in the pimobendan group, and NT-proANP (P = .02) and plasma vasopressin (P = .01) decreased in the benazepril group.
  
  
  CONCLUSIONS
  Pimobendan improves short-term cardiac function more than benazepril in dogs with CHF caused by MMVD. Pimobendan treatment enables the heart to work at smaller end-systolic and diastolic dimensions while maintaining adequate forward stroke volume. Some of the treatment responses found in neuroendocrine profile might have therapeutic relevance.
authors.affiliation: Department of Clinical Sciences, Faculty of Veterinary Medicine and Animal Science, Swedish University of Agricultural Sciences, Uppsala, Sweden.
authors.forename: J
authors.initials: J
authors.lastname: Häggström
authors.forename: P F
authors.initials: PF
authors.lastname: Lord
authors.forename: K
authors.initials: K
authors.lastname: Höglund
authors.forename: I
authors.initials: I
authors.lastname: Ljungvall
authors.forename: O
authors.initials: O
authors.lastname: Jöns
authors.forename: C
authors.initials: C
authors.lastname: Kvart
authors.forename: K
authors.initials: K
authors.lastname: Hansson
mesh_terms: D000450:Aldosterone / Q000097:blood; D000818:Animals; D009320:Atrial Natriuretic Factor / Q000097:blood; D001552:Benzazepines / Q000494:pharmacology* / Q000627:therapeutic use; D002316:Cardiotonic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D004232:Diuretics / Q000494:pharmacology / Q000627:therapeutic use; D004283:Dog Diseases / Q000188:drug therapy / Q000503:physiopathology*; D004285:Dogs; D004452:Echocardiography / Q000662:veterinary; D005260:Female; D005665:Furosemide / Q000494:pharmacology / Q000627:therapeutic use; D006333:Heart Failure / Q000188:drug therapy / Q000503:physiopathology / Q000662:veterinary*; D006339:Heart Rate / Q000502:physiology; D006349:Heart Valve Diseases / Q000188:drug therapy / Q000503:physiopathology / Q000662:veterinary*; D008297:Male; D008943:Mitral Valve / Q000187:drug effects / Q000503:physiopathology*; D020097:Natriuretic Peptide, Brain / Q000097:blood; D009929:Organ Size / Q000502:physiology; D010446:Peptide Fragments / Q000097:blood; D011446:Prospective Studies; D011498:Protein Precursors / Q000097:blood; D011724:Pyridazines / Q000494:pharmacology* / Q000627:therapeutic use; D013318:Stroke Volume / Q000502:physiology; D014667:Vasopressins / Q000097:blood
chemical_list: D001552:Benzazepines; D002316:Cardiotonic Agents; D004232:Diuretics; C099254:N-terminal proatrial natriuretic peptide; D010446:Peptide Fragments; D011498:Protein Precursors; D011724:Pyridazines; C109794:pro-brain natriuretic peptide (1-76); D014667:Vasopressins; D020097:Natriuretic Peptide, Brain; C041648:pimobendan; D000450:Aldosterone; D005665:Furosemide; D009320:Atrial Natriuretic Factor; C044946:benazepril
keywords: Canine; Heart rate; Heart size; Mitral regurgitation; Therapy