Effects of [beta]-blockers on ventilation efficiency in heart failure

• Published in: The American heart journal Vol. 159; no. 6; p. 1067
• Main Authors: Agostoni, Piergiuseppe, Apostolo, Anna, Cattadori, Gaia, Salvioni, Elisabetta, Berna, Giovan ni, Antonioli, Laura, Vignati, Carlo, Schina, Mauro, Sciomer, Susanna, Bussotti, Maurizio, Palermo, Pietro, Fiorentini, Cesare, Contini, Mauro
• Format: Journal Article
• Language: English
• Published: Philadelphia Elsevier Limited 01.06.2010
• Subjects: Carbon dioxide; Cardiovascular disease; Drug dosages; Efficiency; Heart failure; Heart rate; Hypertension; Lung diseases; Quality of life; Variance analysis; Ventilation
• ISSN: 0002-8703; 1097-6744
• DOI: 10.1016/j.ahj.2010.03.034

Background Hyperventilation and consequent reduction of ventilation (VE) efficiency are frequently observed during exercise in heart failure (HF) patients, resulting in an increased slope of VE/carbon dioxide (VE/Vco2) relationship. The latter is an independent predictor of HF prognosis. β-Blockers improve the prognosis of HF patients. We evaluated the effect on the efficiency of VE of a β1-β2unselective (carvedilol) versus a β1selective (bisoprolol) β-blocker. Methods We analyzed consecutive maximal cardiopulmonary exercise tests performed on 572 clinically stable HF patients (New York Heart Association class I-III, left ventricle ejection fraction ≤50%) categorized in 3 groups: 81 were not treated with β-blocker, 304 were treated with carvedilol, and 187 were treated with bisoprolol. Clinical conditions were similar. Results The VE/Vco2slope was lower in carvedilol- compared with bisoprolol-treated patients (29.7 ± 0.4 vs 31.6 ± 0.5,P= .023, peak oxygen consumption adjusted) and with patients not receiving β-blockers (31.6 ± 0.7,P= .036). Maximum end-tidal CO2pressure during the isocapnic buffering period was higher in patients treated with carvedilol (39.0 ± 0.3 mm Hg) than with bisoprolol (37.2 ± 0.4 mm Hg,P< .001) and in patients not receiving β-blockers (37.2 ± 0.5 mm Hg,P= .001). Conclusions Reduction of hyperventilation, with improvement of VE efficiency during exercise (reduction of VE/Vco2slope and increase of maximum end-tidal CO2pressure), is specific to carvedilol (β1-β2unselective blocker) and not to bisoprolol (β1-selective blocker).