Comparison of the effects of carvedilol and metoprolol on exercise ventilatory efficiency in patients with congestive heart failure

Circ J. 2008 Mar;72(3):358-63. doi: 10.1253/circj.72.358.


Background: The slope of the relationship between ventilation and carbon dioxide production (VE/VCO2 slope), obtained during symptom-limited ramp exercise testing, reflects exercise ventilatory efficiency. Importantly, the VE/VCO2 slope is related to prognosis in patients with congestive heart failure (CHF). The aim of the present study was to determine the relationship between the institution of beta-blockers, carvedilol or metoprolol, and the VE/VCO2 slope during exercise in patients with CHF.

Methods and results: Fifty-seven patients with New York Heart Association functional class II or III with a radionuclide left ventricular ejection fraction (LVEF) of less than 40% received carvedilol or metoprolol in a randomized fashion. The VE/VCO2 slope, LVEF and plasma brain natriuretic peptide (BNP) concentration were determined before and after 16 weeks of treatment. LVEF improved (p<0.01), but the VE/VCO2 slope and BNP did not. A significant improvement in the VE/VCO2 slope was observed in patients with LVEF <29% or BNP >63 pg/ml (respective baseline median values) (p<0.05, p<0.05). In patients with BNP >63 pg/ml, the improvement effect on the VE/VCO2 slope with carvedilol was significantly greater than that with metoprolol (p<0.05) and a significant improvement in the VE/VCO2 slope was observed only in those who took carvedilol (p<0.01).

Conclusions: The VE/VCO2 slope was not improved after beta-blocker therapy in any of the patients. However, it did improve in patients with a lower LVEF or higher BNP level at baseline, and carvedilol was more effective than metoprolol in improving the VE/VCO2 slope in patients with higher BNP levels at baseline.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adrenergic beta-Antagonists / pharmacology*
  • Adrenergic beta-Antagonists / therapeutic use
  • Aged
  • Blood Pressure / physiology
  • Carbazoles / pharmacology*
  • Carbazoles / therapeutic use
  • Carbon Dioxide / metabolism*
  • Carvedilol
  • Dose-Response Relationship, Drug
  • Exercise / physiology*
  • Female
  • Heart Failure / drug therapy
  • Heart Failure / metabolism
  • Heart Failure / physiopathology*
  • Humans
  • Male
  • Metoprolol / pharmacology*
  • Metoprolol / therapeutic use
  • Middle Aged
  • Natriuretic Peptide, Brain / blood
  • Oxygen Consumption / physiology
  • Prognosis
  • Propanolamines / pharmacology*
  • Propanolamines / therapeutic use
  • Pulmonary Ventilation / drug effects*
  • Pulmonary Ventilation / physiology
  • Stroke Volume / physiology


  • Adrenergic beta-Antagonists
  • Carbazoles
  • Propanolamines
  • Carvedilol
  • Natriuretic Peptide, Brain
  • Carbon Dioxide
  • Metoprolol