Lung function with carvedilol and bisoprolol in chronic heart failure: is beta selectivity relevant?
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.


OBJECTIVE
To compare the effects of carvedilol and bisoprolol on lung function in patients with chronic heart failure (CHF).


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%.


CONCLUSIONS
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
Piergiuseppe
P
Centro Cardiologico Monzino, IRCCS, Istituto di Cardiologia, Università di Milano, Milan, Italy. piergiuseppe.agostoni@ccfm.it
Contini
Mauro
M
Cattadori
Gaia
G
Apostolo
Anna
A
Sciomer
Susanna
S
Bussotti
Maurizio
M
Palermo
Pietro
P
Fiorentini
Cesare
C
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology* / Q000627:therapeutic use; D000368:Aged; D017298:Bisoprolol / Q000627:therapeutic use*; D002227:Carbazoles / Q000494:pharmacology* / Q000627:therapeutic use; D000077261:Carvedilol; D002908:Chronic Disease; D018592:Cross-Over Studies; D004311:Double-Blind Method; D015444:Exercise / Q000502:physiology; D005260:Female; D006333:Heart Failure / Q000188:drug therapy* / Q000503:physiopathology*; D006439:Hemodynamics; D006801:Humans; D008168:Lung / Q000187:drug effects / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000187:drug effects; D011412:Propanolamines / Q000494:pharmacology* / Q000627:therapeutic use; D011653:Pulmonary Diffusing Capacity / Q000187:drug effects / Q000502:physiology; D012129:Respiratory Function Tests
D000319:Adrenergic beta-Antagonists; D002227:Carbazoles; D011412:Propanolamines; D000077261:Carvedilol; D017298:Bisoprolol