Sunday, 26 August 2012

Abstract

Purpose: Several beta blockers are available for heart failure (HF) treatment but only few comparative data among molecules are available. We compared Carvedilol (beta1, beta2, alpha blocker) (C), Bisoprolol (beta1 blocker) (B), and Nebivolol (beta1 blocker with NO releasing activity) (N). Methods: We studied 61 moderate HF patients (age 61+9 years) in stable clinical conditions. Patients were randomized to receive, for 2 months, C, B, N in a blind, cross‐over design. Avearage daily dose were 25.6+12.5, 4.9+2.4 and 5.0+2.4 mg for C, B, N, respectively. At the end of each period, patients underwent: spirometry with lung diffusion measure (DLco and its subcomponents Dm Main results (Table Presented) and Vc), chemoreceptor sensitivity to CO2 and maximal cardiopulmonary exercise test. Results (table): No significant difference were observed in lung mechanics and peak exercise heart rate. On C membrane diffusion and exercise capacity were worse while ventilation efficiency, as measured by VE/VCO2 slope, better than on B or N. Both peripheral and central sensitivity to CO2 were higher with B than with C. Conclusions: beta‐blockers differently affected cardiopulmonary function in patients withmoderate HF. B and N caused an amelioration in lung diffusion in comparison with C and a better exercise performance, the former due to a lower interference with beta2‐mediated alveolar fluid clearance. C, however, allowed a better ventilation efficiency during exercise likely via a different chemoreceptor modulation. Results from this study could represent a basis for identifying the best match between a specific beta blocker compound and a specific HF patient.