Chest
Volume 148, Issue 4, October 2015, Pages 945-952
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Original Research
Sleep Disorders
Severity of OSA Is an Independent Predictor of Incident Atrial Fibrillation Hospitalization in a Large Sleep-Clinic Cohort

https://doi.org/10.1378/chest.15-0229Get rights and content

BACKGROUND

OSA is a common condition that has been associated with atrial fibrillation (AF), but there is a paucity of data from large longitudinal cohorts to establish whether OSA is a risk factor for AF independent of obesity and other established risk factors.

METHODS

We studied patients attending a sleep clinic referred for in-laboratory polysomnography for possible OSA between 1989 and 2001. Whole-population hospital data in Western Australia for 1970 to 2009 were linked to sleep study cases to determine incident AF hospitalization to 2009. Cox regression analyses were used to assess the independent association of OSA with incident AF.

RESULTS

Study case subjects (6,841) were predominantly middle aged (48.3 ± 12.5 years old) and men (77%), and 455 developed AF during a median 11.9 years of follow-up. Univariate predictors of AF included age, BMI, hypertension, diabetes, valvular heart disease, coronary or peripheral artery disease, heart failure, and COPD (all P .001). After multivariable adjustment, independent predictors of incident AF were an apnea/hypopnea index (AHI) > 5/h (hazard ratio [HR], 1.55; 95% CI, 1.21-2.00), log (AHI 1 1) (HR, 1.15; 95% CI, 1.06-1.26), and log (time with oxygen saturation < 90% 1 1) (HR, 1.12; 95% CI, 1.06-1.19). There were no interactions between age, sex, or BMI and AHI for AF development.

CONCLUSIONS

OSA diagnosis and severity are independently associated with incident AF. Clinical trials are required to determine if treatment of OSA will reduce the burden of AF.

Section snippets

Results

Table 1 shows the baseline clinical and PSG characteristics of the 6,841 sleep clinic patients in the study cohort, stratified by incident AF. The cohort was predominantly middle aged (48.3 ± 12.5 years old) and male sex (77%), with a wide range of AHI (median [lower quartile, upper quartile] 8.90 [2.50, 23.50] events/h) (Table 1). Patients had a history of cardiovascular risk factors and comorbidities commonly found among patients attending sleep clinics, but a relatively low baseline rate of

Discussion

We found that a PSG-confirmed diagnosis of OSA (AHI > 5 events/h) is associated with increased rates of incident AF hospitalization over a median 12 years of follow-up, independent of obesity and other established AF risk factors. Additionally, there is a dose-response relationship between OSA severity and rates of incident AF. In particular, the AHI, whether expressed as a continuous variable or stratified by commonly used clinical cut points, and Sao2t < 90% have independent graded

Conclusions

This large clinic-based cohort of patients assessed for OSA using laboratory-based PSG found an independent association between the presence and severity of OSA and incident AF over a median 12-year follow-up period. Our data support a growing evidence base that OSA is an important novel and potentially modifiable risk factor for the development of AF. Randomized interventional studies are required to ascertain whether treatment of OSA can reduce the incident or recurrent burden of AF.

Acknowledgments

Author contributions: G. C. had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis, including and especially any adverse effects. G. C., N. M., T. B., D. R. H., L. S., M. K., and J. H. contributed substantially to the study design, data analysis, and interpretation and the writing of the manuscript.

Conflict of interest: N. M. and D. R. H. have received research support from ResMed. N. M. has received an

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  • Cited by (0)

    FUNDING/SUPPORT: The study was supported by the National Health and Medical Research Council project [Grant 1020373] and a Ray Florence Shaw Award [2013/14-001].

    Reproduction of this article is prohibited without written permission from the American College of Chest Physicians. See online for more details.

    Originally published Online First April 30, 2015.

    Drs Cadby and McArdle contributed equally to this manuscript.

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