Hemodynamic and sympathoinhibitory effects of nasal CPAP in congestive heart failure

Despite advances in medical therapy of congestive heart failure (CHF), morbidity and mortality for this disorder remain high. One factor that could contribute to the poor prognosis of CHF is Cheyne-Stokes respiration with central sleep apnea (CSR-CSA). This breathing disorder is a frequent complication of CHF, where it is associated with increased mortality. One reason for this higher mortality may be that apnea-related hypoxia and arousals from sleep can increase sympathetic nervous system activity (SNA), as manifested by increases in overnight urinary and daytime plasma norepinephrine concentrations ([UNE] and [PNE], respectively). Recently published randomized trials have demonstrated that nasal continuous positive airway pressure (CPAP), if applied nightly at high enough levels over periods of at least 1-3 months, can alleviate CSR-CSA in patients with CHF in association with hemodynamic improvement, as evidenced by increased left ventricular ejection fraction (LVEF) and inhibition of SNA, as manifest by reductions in [UNE] and [PNE]. These findings indicate a role for CPAP as a non-pharmacologic adjunctive therapy for CHF complicated by CSR-CSA. Longer-term trials of CPAP are needed to determine whether this intervention can provide long-lasting clinical benefit to patients with CHF and CSR-CSA.