Impaired functional capacity predicts mortality in patients with obstructive sleep apnea.

Publication/Presentation Date

9-1-2014

Abstract

BACKGROUND: Obstructive sleep apnea (OSA) is associated with increased mortality, for which impaired functional capacity (IFC) has been established as a surrogate. We sought to assess whether IFC is associated with increased mortality in patients with OSA and whether IFC is predictive of increased mortality after accounting for coronary artery disease.

METHODS: Patients with OSA who underwent both polysomnography testing and exercise stress echocardiogram were selected. Records were reviewed retrospectively for demographics, comorbidities, stress echocardiographic parameters, and polysomnography data. Univariable and multivariable logistic regression analysis was used to evaluate the association between IFC and overall mortality. We then evaluated the variables associated with IFC in the overall population and in the subgroup with normal Duke treadmill score (DTS).

RESULTS: In our cohort, 404 (26%) patients had IFC. The best predictors of IFC were female sex, history of smoking, ejection fraction less than 55, increased body mass index, presence of comorbidities, abnormal exercise echocardiogram, abnormal heart rate recovery, and abnormal DTS. Compared with those without IFC, patients with IFC were 5.1 times more likely to die (odds ratio [OR], 5.1; 95% confidence interval [CI], 2.5-10.5; P < 0.0001) by univariate analysis and 2.7 times more likely to die (OR, 2.7; 95% CI, 1.2-6.1; P = 0.02) by multivariate analysis, when accounting for heart rate recovery, DTS, and sleep apnea severity. Among those without coronary artery disease, patients with IFC were at significantly increased risk of mortality (OR, 4.3; 95% CI, 1.35-13.79; P = 0.0088) compared with those with preserved functional capacity.

CONCLUSIONS: In our OSA population, IFC was a strong predictor of increased mortality. Among those with normal DTS, IFC identified a cohort at increased risk of mortality.

Volume

11

Issue

7

First Page

1056

Last Page

1063

ISSN

2325-6621

Disciplines

Medicine and Health Sciences

PubMedID

24983954

Department(s)

Department of Medicine

Document Type

Article

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