Effect of β-adrenergic receptor stimulation on lung fluid in stable heart failure patients.

BACKGROUND

The purpose of this study was to determine: (1) whether stable heart failure patients with reduced ejection fraction (HFrEF) have elevated extravascular lung water (EVLW) when compared with healthy control subjects; and (2) the effect of acute β-adrenergic receptor (βAR) agonist inhalation on lung fluid balance.

METHODS

Twenty-two stable HFrEF patients and 18 age- and gender-matched healthy subjects were studied. Lung diffusing capacity for carbon monoxide (DLCO), alveolar-capillary membrane conductance (Dm), pulmonary capillary blood volume (V) (via re-breathe) and lung tissue volume (V) (via computed tomography) were assessed before and within 30 minutes after administration of nebulized albuterol. EVLW was derived as V - V.

RESULTS

Before administration of albuterol, V and EVLW were higher in HFrEF vs control (998 ± 200 vs 884 ± 123 ml, p = 0.041; and 943 ± 202 vs 802 ± 133 ml, p = 0.015, respectively). Albuterol decreased V and EVLW in HFrEF patients (-4.6 ± 7.8%, p = 0.010; -4.6 ± 8.8%, p = 0.018) and control subjects (-2.8 ± 4.9%, p = 0.029; -3.0 ± 5.7%, p = 0.045). There was an inverse relationship between pre-albuterol values and pre- to post-albuterol change for EVLW (r = -0.264, p = 0.015) and Dm (r = -0.343, p = 0.004) in HFrEF only.

CONCLUSION

Lung fluid is elevated in stable HFrEF patients relative to healthy subjects. Stimulation of βARs may cause fluid removal in HFrEF, especially in patients with greater evidence of increased lung water at baseline.