title: Prospective crossover comparison of carvedilol and metoprolol in patients with chronic heart failure.
abstract: OBJECTIVE
  This study investigates the effects of a change of beta-adrenergic blocking agent treatment from metoprolol to carvedilol and vice versa in patients with heart failure (HF).
  
  
  BACKGROUND
  Beta-blockers improve ventricular function and prolong survival in patients with HF. It has recently been suggested that carvedilol has more pronounced effects on left ventricular ejection fraction (LVEF) compared with metoprolol. It is uncertain whether a change from one beta-blocker to the other is safe and leads to any change of left ventricular function.
  
  
  METHODS
  Forty-four patients with HF due to ischemic (n = 17) or idiopathic cardiomyopathy (n = 27) that had responded well to long-term treatment with either metoprolol (n = 20) or carvedilol (n = 24) were switched to an equivalent dose of the respective other beta-blocker. Before and six months after crossover of treatment, echocardiography, radionuclide ventriculography and dobutamine stress echocardiography were performed.
  
  
  RESULTS
  Six months after crossover of beta-blocker treatment, LVEF had further improved with both carvedilol and metoprolol (carvedilol: 32 +/- 3% to 36 +/- 4%; metoprolol: 27 +/- 4% to 30 +/- 5%; both p < 0.05 vs. baseline), without interindividual differences. There were no changes in either New York Heart Association functional class or any other hemodynamic parameters at rest. Dobutamine stress echocardiography revealed a more pronounced increase of heart rate after dobutamine infusion in metoprolol- compared with carvedilol-treated patients. After dobutamine infusion, LVEF increased in the carvedilol- but not in the metoprolol-treated group.
  
  
  CONCLUSIONS
  When switching treatment from one beta-blocker to the other, improvement of LVEF in patients with HF is maintained. Despite similar long-term effects on hemodynamics at rest, beta-adrenergic responsiveness is different in both treatments.
authors.affiliation: Medizinische Klinik und Poliklinik, Innere Medizin III, Universitätskliniken des Saarlandes, Homburg, Germany. maack@med-in.uni-saarland.de
authors.forename: C
authors.initials: C
authors.lastname: Maack
authors.forename: T
authors.initials: T
authors.lastname: Elter
authors.forename: G
authors.initials: G
authors.lastname: Nickenig
authors.forename: K
authors.initials: K
authors.lastname: LaRosee
authors.forename: M
authors.initials: M
authors.lastname: Crivaro
authors.forename: A
authors.initials: A
authors.lastname: Stäblein
authors.forename: H
authors.initials: H
authors.lastname: Wuttke
authors.forename: M
authors.initials: M
authors.lastname: Böhm
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D002227:Carbazoles / Q000494:pharmacology / Q000627:therapeutic use*; D000077261:Carvedilol; D002908:Chronic Disease; D018592:Cross-Over Studies; D005260:Female; D006333:Heart Failure / Q000188:drug therapy* / Q000503:physiopathology; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008790:Metoprolol / Q000494:pharmacology / Q000627:therapeutic use*; D008875:Middle Aged; D011412:Propanolamines / Q000494:pharmacology / Q000627:therapeutic use*; D011446:Prospective Studies; D013318:Stroke Volume; D016277:Ventricular Function, Left / Q000187:drug effects
chemical_list: D000319:Adrenergic beta-Antagonists; D002227:Carbazoles; D011412:Propanolamines; D000077261:Carvedilol; D008790:Metoprolol