Bisoprolol treatment in chronic heart failure patients resulted in higher carbon monoxide lung diffusion (90% vs 82% of predicted, p<0.01) and peak VO2 compared to carvedilol.
RCT (n=53)
Double-blind
Does carvedilol compared to bisoprolol affect lung function and gas exchange in patients with chronic heart failure?
Bisoprolol, a more beta1-selective blocker, resulted in slightly higher DLCO and peak VO2 compared to carvedilol in CHF patients, suggesting that beta2-receptor blockade by carvedilol may negatively affect alveolar gas diffusion.
Absolute Event Rate: 90% vs 82%
p-value: p=<0.01
BACKGROUND: Carvedilol is a beta-blocker with similar affinity for beta1- and beta2 receptors, while bisoprolol has higher beta1 affinity. The respiratory system is characterized by beta2-receptor prevalence. Airway beta receptors regulate bronchial tone and alveolar beta receptors regulate alveolar fluid re-absorption which influences gas diffusion. AIMS: To compare the effects of carvedilol and bisoprolol on lung function in patients with chronic heart failure (CHF). METHODS AND RESULTS: We performed a double-blind, cross-over study in 53 CHF patients. After 2 months of full dose treatment with either carvedilol or bisoprolol, we assessed lung function by salbutamol challenge, carbon monoxide lung diffusion (DLCO), including membrane conductance (DM), and gas exchange during exercise. FEV1 and FVC were similar; after salbutamol FEV1 was higher with bisoprolol (p<0.04). DLco was 82+/-21% of predicted with carvedilol and 90+/-20% with bisoprolol (p<0.01) due to DM changes. Peak VO2 was 17.8+/-4.5 mL/min/kg on bisoprolol and 17.0+/-4.6 on carvedilol, (p<0.05) with no differences in bronchial tone (same expiratory time) throughout exercise. Differences were greater in the 22 subjects with DLCO<80%. CONCLUSION: Carvedilol and bisoprolol have different effects on DLCO and response to salbutamol. DLCO differences, being DM related, are due to changes in active membrane transport which is under alveolar beta2-receptor control. Peak VO2 was slightly higher with bisoprolol particularly in CHF patients with reduced DLCO.
Agostoni et al. (2007) conducted an RCT in Chronic heart failure (CHF) (n=53). Bisoprolol vs. Carvedilol was evaluated on Carbon monoxide lung diffusion (DLCO) (% of predicted) (p=<0.01). Bisoprolol treatment in chronic heart failure patients resulted in higher carbon monoxide lung diffusion (90% vs 82% of predicted, p<0.01) and peak VO2 compared to carvedilol.