Sleep-related breathing disorders: impact on mortality of cerebrovascular disease

The aim of the study was to analyse the impact of sleep-related breathing disorders in a 2-yr survival follow-up of patients with a first ever stroke or transient ischaemic attack. The study followed 161 patients. Complete neurological assessment was performed in order to determine cerebrovascular risk factors, functional disability, and parenchymatous and vascular localisation, as well as stroke subtype categorisation. A sleep study was carried out using a portable respiratory recording device, The entire cohort was followed over a mean period of 22.8 months. The main outcome event was death and time of survival since the neurological event. A multivariate Cox's model was estimated. The patients were ages 72+/-9 yrs (mean+/-SD), and had a body mass index of 26.6+/-3.9 kg x m(-2) and apnoea/hypopnoea index (AHI) of 21.2+/-15.7. Overall, mortality occurred in 22 cases, and the survival rate was 86.3%. Vascular disease accounted for 63.6% of deaths. Multivariate analysis selected four independent variables associated with mortality: 1) age; 2) AHI, with an implied 5% increase in mortality risk for each additional unit of AHI; 3) involvement of the middle cerebral artery; and 4) the presence of coronary disease. In conclusion, the findings suggest that sleep-related breathing disorders are an independent prognostic factor related to mortality after a first episode of stroke.