CPAP Treatment for Sleep Apnea May Improve Neurologic Outcomes After Stroke

Continuous positive airway pressure (CPAP) treatment for sleep apnea may improve neurologic outcomes in patients with comorbid stroke or transient ischemic attack (TIA), according to results of a meta-analysis published in the Journal of Clinical Sleep Medicine.

Sleep apnea is considered a modifiable risk factor for stroke. While CPAP is the standard treatment for sleep apnea, its use among patients with comorbid stroke is not universally agreed upon. For the study, researchers assessed the practicality and efficacy of CPAP treatment among patients with sleep apnea and stroke.

The researchers from China searched PubMed, EMBASE, and the Cochrane Library from inception to July 28, 2022 for randomized controlled trials (RCTs) comparing CPAP vs standard treatments for sleep apnea in patients with a history of comorbid stroke or TIA. Primary outcomes included CPAP treatment feasibility and changes in patients’ neurologic function and functional status throughout the intervention. Secondary outcomes included recurrent vascular events, changes in cognitive function, depression, sleepiness, and changes on the apnea-hypopnea index (AHI).

A total of 14 eligible RCTs were included in the meta-analysis, consisting of pooled information on 1065 individuals with stroke or TIA — 564 in the intervention group and 501 in the control group. Half of included studies did not differentiate between ischemic or hemorrhagic stroke types, whereas 4 studies included patients with ischemic stroke, 2 included patients with either ischemic stroke or TIA, and 1 study included patients with only TIA.

Participants in the intervention group received CPAP treatment of variable duration, ranging from 72 hours to 24 months. In 5 of the 14 studies, early intervention with CPAP treatment was initiated within 7 days following stroke, whereas CPAP treatment in the remaining 7 studies was initiated between 7 days to 6 months following stroke.

Among the 8 RCTs that reported on CPAP adherence, patients used CPAP treatment for an average of greater than 4 hours per night in 7 studies and less than 4 hours per night in 1 study.

A total of 7 studies used the National Institute of Health Stroke Scale to determine the efficacy of CPAP treatment on neurologic function, while 2 studies used the Canadian Neurological Scale. Functional status was assessed using the Barthel Index in 7 studies, while the remaining 2 used the motor section of the Functional Independence Measure and the physical function subscale in Utrecht Scale for Evaluation of Rehabilitation.  

Study participants with comorbid stroke and sleep apnea who were treated with CPAP demonstrated improvement in neurologic function compared with participants in the control group (standardized mean difference [SMD], 0.28; 95% CI, 0.02-0.53; P =.03). However, use of CPAP did not significantly change functional status between the groups (SMD, 0.25; 95% CI, -0.01 to 0.51; P =.06).

Recurrent vascular events did not occur at higher rates in the control group compared with the CPAP group (11.38% vs. 7.95%; risk ratio, 0.70; 95% CI, 0.37-1.32; P =.27).

CPAP intervention did not significantly improve cognitive function (SMD, 0.34; 95% CI, -0.38 to 1.07; P =.35), depression (SMD, -0.42; 95% CI, -0.86 to 0.03; P =.07), or sleepiness (SMD, -0.49; 95% CI, -1.06 to 0.08; P =.09) compared with the control group.

The only notable change among secondary outcomes was significant AHI reduction in the CPAP group compared with the control group (mean change, -20.59 events/h; 95% CI, -26.30 to -14.87; P <.01).

In addition to the heterogeneity among trials, these results were further limited by moderate risk of bias among all included studies, small sample sizes, and variations in the clinical presentation of stroke among each study population.

“CPAP therapy is [a] feasible modality in patients with stroke associated with SA [sleep apnea] and improves neurological outcomes in these patients,” the researchers noted. “However, this finding should be interpreted with caution because of the substantial heterogeneity of trials and low literature quality,” they added.