Treating Sleep-Disordered Breathing for Cardiovascular Outcomes: Observational and Randomised Trial Evidence.

Abstract

Sleep-disordered breathing (SDB) is considered a risk factor for cardiovascular disease. Obstructive sleep apnea (OSA) can be treated with continuous positive airway pressure and central sleep apnea (CSA), in patients with heart failure and reduced ejection fraction (HFrEF), by peak-flow-triggered adaptive servo-ventilation (ASVPF). Presently, there is equipoise as to whether treating SDB prevents cardiovascular events. Some propose treatment for this indication, based on observational data, while others argue against because of the lack of randomised trial evidence. This review evaluates literature concerning the cardiovascular effects of treating SDB with positive airway pressure devices in individuals with and without cardiovascular diseases. Nine observational studies report significantly lower cardiovascular event rates in those treated, than in those not treated, for SDB. Conversely, 12 randomised trials in which excessive daytime sleepiness was generally an exclusion criterion showed no reduction in cardiovascular event rates. The SERVE-HF trial showed an increase in mortality with use of minute ventilation triggered ASV for CSA in patients with HFrEF. In the ADVENT-HF trial, treating HFrEF patients with co-existing OSA or CSA using ASVPF was safe and improved sleep structure and heart failure-related quality of life but did not reduce all-cause mortality or cardiovascular events. More evidence is required to determine whether treating CSA in patients with HRrEF prevents cardiovascular events and improves survival. Presently, the rationale for treating SDB with PAP remains improving sleep structure and quality of life, as well as relieving excessive daytime sleepiness, but not reducing cardiovascular events.