The effect of salbutamol on skeletal muscle in chronic heart failure

We performed a randomised placebo-controlled trial to investigate the effects of the anabolic drug salbutamol on skeletal muscle and exercise capacity in chronic heart failure. Twelve patients received salbutamol slow-release 8 mg twice daily or placebo for 3 weeks. We assessed the effect of treatment on exercise capacity, quadriceps muscle bulk, maximal isometric strength and fatigue, respiratory muscle strength, spirometry and 24-h ECG (electrocardiogram). There was no significant change in the muscle indices, exercise time or peak oxygen consumption. The frequency of ventricular arrhythmias and spirometric measurements were also unchanged. Maximal expiratory mouth pressure, measured at total lung capacity and functional residual capacity, increased significantly (+29.7±10.6 vs. −0.5±7.5 cm H2O [mean±S.E.M., change over 3 weeks treatment salbutamol vs. placebo] and +31.2±5.4 vs. +0.2±4.0 cm H2O both P<0.05). Maximal inspiratory pressures showed a trend towards increasing with treatment when measured from either lung volume (−22.8±9.5 vs. −6.2±3.6 cm H2O, P=0.14 and −21.5±7.5 vs. −3.5±3.4 cm H2O, P=0.054). Treatment with 3 weeks of salbutamol increases respiratory muscle strength in chronic heart failure but does not improve quadriceps abnormalities or exercise capacity. Salbutamol is unlikely to have a role in treating the muscle abnormalities in chronic heart failure.