Abstract 12943: Severity of Sleep-Disordered Breathing Influences the Prognosis of Patients with Chronic Heart Failure
Background: Sleep-disordered breathing (SDB) has been reported to influence the mortality of patients with chronic heart failure (CHF). However the predictors of lethal cardiac events in CHF patients with SDB remain to be elucidated.
Methods: We examined whether the severity of SDB was associated with lethal events in CHF patients, and whether the respiratory therapy for SDB improved the prognosis. Ninety-five patients with stable CHF who had the examination of SDB by overnight polysomonography between August 2000 and November 2008 were enrolled in the present study (62.3±14.5 [SD] years-old, M/F 72/23). SDB events were quantified by the apnea hypopnea index (AHI). All patients with more than 10/h for AHI (n=42) at the initial evaluation, were recommended the respiratory therapy (RT); oxygen therapy (HOT) or continuous positive airway pressure (CPAP). Endpoints in the present study were defined as lethal arrhythmic events (sudden death or ventricular tachyarrhythmia) or lethal events (overall death or ventricular tachyarrhythmia).
Results: During 29±17 months of follow-up, 18 patients died and 10 ventricular tachyarrhythmias occurred. The frequency of lethal events and lethal arrhythmic events increased according to the severity of SDB (lethal events: 10%, 19% and 35%, lethal arrhythmic events: 3%, 14% and 20% in patients with AHI≤5/h, 5/h≤AHI≤15/h and 15/h≤AHI, respectively). The multivariate proportional hazard analysis showed that more than or equal to 5AHI was an effective risk factor both for lethal arrhythmic events (P=0.026) and lethal events (P=0.043). Second, RT were introduced to 24 out of 42 patients with 10≤AHI. It improved the number of AHI from 34.3±12.6 to 15.0±9.3/h, but did not reduce both lethal arrhythmic and lethal event rates compared to those in 18 patients without RT. However, 4 patients who reached less than 5 AHI by RT had neither lethal arrhythmic nor lethal events during follow-up period.
Conclusion: SDB could be one of independent predictors of lethal arrhythmic events and lethal events in patients with CHF. Conventional RT (HOT or CPAP) might improve the prognosis of these events, but a further advanced RT such as an adaptive support ventilator (ASV) is likely to be more effective on the prevention of lethal events.
- © 2013 by American Heart Association, Inc.