Background: Sleep-disordered breathing (SDB) has been reported to influence mortality and occurrence of ventricular tachyarrhythmia in patients with chronic heart failure (CHF). It remains to be elucidated, however, whether respiratory therapy (RT) can affect the occurrence of fatal ventricular tachyarrhythmia in CHF patients with SDB.
Methods and results: We prospectively examined whether the severity of SDB was associated with fatal cardiac events in CHF patients and, if so, whether RT for SDB improved prognosis. We enrolled 95 patients with stable CHF, in whom SDB was examined on overnight polygraphy. The severity of SDB was quantified using the apnea-hypopnea index (AHI). All patients with AHI ≥10 (n=42) at initial evaluation were recommended to have RT, such as home oxygen therapy and continuous positive airway pressure, and 24 agreed to this. During the follow-up period of 29±17 months, 8 ventricular tachyarrhythmias occurred and 14 of the 95 patients died. On multivariate proportional hazard analysis AHI ≥5 was a risk factor for fatal arrhythmic events (P=0.026). Although RT significantly reduced AHI, it did not significantly reduce the event rates, but 4 patients with AHI <5 on RT had no fatal arrhythmic events or death.
Conclusions: SDB is an independent prognostic factor and thus an important therapeutic target in CHF patients.