The Prevalence of Central Sleep Apnea in New Referrals to a Sleep Surgery Clinic

Objective: Surgical treatment of non-obstructive sleep apnea (OSA) pathology poses the risk of inappropriate surgical indications. Herein, we sought to determine the prevalence of non-OSA respiratory disorders, specifically central sleep apnea (CSA), in new referrals to a Sleep Surgery Clinic.

Study design: Prospective observational review.

Setting: Tertiary care academic medical center.

Methods: In a sleep surgery clinic cohort, the presence of clinically significant CSA was defined as having >25% of the total apnea-hypopnea index (AHI) being central and/or mixed events. Demographics, comorbid disorders, patient-reported outcome measurements, and sleep study results were compared among patients using linear or logistic regression analysis, unadjusted and adjusted for age, sex, and body mass index (BMI).

Results: On average, the cohort (n = 295) was male (74%), middle-aged (mean [±SD] 54.2 ± 13.9 years), and overweight (BMI 30.3 ± 5.4), with severe sleep apnea (AHI 30.6 ± 22.6 events/h). Twenty-nine patients (9.8%) were found to have clinically significant CSA yet only 10% of these cases carried a diagnosis of CSA upon presentation. The remainder were identified by reviewing the pre-visit sleep study tables (35%), raw data (17%), and tables and raw data of a repeat post-visit study (38%). Patients with CSA were older and had evidence of more cardiac comorbidities.

Conclusion: The prevalence of CSA in new referrals to a Sleep Surgery Clinic was nearly 1 in 10 despite only 1% (3 of 295) with a known diagnosis upon presentation. Sleep surgeons must remain vigilant for patients with occult CSA, especially in older patients with a history of significant cardiovascular disease.