Association Between Risk of Obstructive Sleep Apnea and Cerebrovascular Reactivity in Stroke Patients

BACKGROUND: Obstructive sleep apnea (OSA) is present in 60% to 70% of stroke patients. Cerebral vasoreactivity in patients with stroke and OSA has not been well studied and could identify a new pathophysiologic mechanism with potential therapeutic intervention. We aimed to determine whether risk categories for OSA are associated with cerebral vasoreactivity in stroke patients. METHODS AND RESULTS: In this cross‐sectional study of a cohort of patients with stroke, we used clinical questionnaires (Sleep Obstructive Apnea Score Optimized for Stroke [SOS] and snoring, tiredness, observed, pressure, bmi, age, neck, gender [STOP‐BANG] scores) to assess the risk of OSA and transcranial Doppler to assess cerebral vasoreactivity (breath‐holding index and visual evoked flow velocity response). Of the 99 patients included, 77 (78%) had medium or high risk of OSA and 80 performed transcranial Doppler. Mean breath‐holding index was 0.52±0.37, and median visual evoked flow velocity response was 10.8% (interquartile range: 8.8–14.5); 54 of 78 (69%) showed impaired anterior circulation vasoreactivity (breath‐holding index <0.69) and 53 of 71 (75%) showed impaired posterior circulation vasoreactivity (visual evoked flow velocity response ≤14.0%). There was a significant negative correlation between the risk of OSA calculated by STOP‐BANG and the breath‐holding index (r(S)=−0.284, P=0.012). The following variables were associated with low anterior circulation vasoreactivity: dyslipidemia (odds ratio: 4.7; 95% CI, 1.5–14.2) and STOP‐BANG score (odds ratio: 1.7 per 1‐point increase; 95% CI, 1.1–1.5). CONCLUSIONS: A high risk of OSA and impaired vasoreactivity exists in the population that has had stroke. Dyslipidemia and STOP‐BANG sleep apnea risk categories were independently associated with impaired anterior circulation vasoreactivity.