Effects of β-blockers on ventilation efficiency in heart failure

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• 作者：Piergiuseppe Agostoni ; Anna Apostolo ; Gaia Cattadori ; Elisabetta Salvioni ; Giovanni Berna ; Laura Antonioli ; Carlo Vignati ; Mauro Schina ; Susanna Sciomer ; Maurizio Bussotti ; Pietro Palermo ; Cesare Fior
• 刊名：American Heart Journal
• 出版年：2010
• 出版时间：June 2010
• 年：2010
• 卷：159
• 期：6
• 页码：1067-1073
• 全文大小：194 K

文摘

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-β₂ unselective (carvedilol) versus a β₁ selective (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/Vco₂ slope 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 CO₂ pressure 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/Vco₂ slope and increase of maximum end-tidal CO₂ pressure), is specific to carvedilol (β₁-β₂ unselective blocker) and not to bisoprolol (β₁-selective blocker).