SLEAP SMART (Sleep Apnea Screening Using Mobile Ambulatory Recorders After TIA/Stroke): A Randomized Controlled Trial.

BACKGROUND AND PURPOSE: Poststroke/transient ischemic attack obstructive sleep apnea (OSA) is prevalent, linked with numerous unfavorable health consequences, but remains underdiagnosed. Reasons include patient inconvenience and costs associated with use of in-laboratory polysomnography (iPSG), the current standard tool. Fortunately, home sleep apnea testing (HSAT) can accurately diagnose OSA and is potentially more convenient and cost-effective compared with iPSG. Our objective was to assess whether screening for OSA in patients with stroke/transient ischemic attack using HSAT, compared with standard of care using iPSG, increased diagnosis and treatment of OSA, improved clinical outcomes and patient experiences with sleep testing, and was a cost-effective approach. METHODS: We consecutively recruited 250 patients who had sustained a stroke/transient ischemic attack within the past 6 months. Patients were randomized (1:1) to use of (1) HSAT versus (2) iPSG. Patients completed assessments and questionnaires at baseline and 6-month follow-up appointments. Patients diagnosed with OSA were offered continuous positive airway pressure. The primary outcome was compared between study arms via an intention-to-treat analysis. RESULTS: At 6 months, 94 patients completed HSAT and 71 patients completed iPSG. A significantly greater proportion of patients in the HSAT arm were diagnosed with OSA (48.8% versus 35.2%, P=0.04) compared with the iPSG arm. Furthermore, patients assigned to HSAT, compared with iPSG, were more likely to be prescribed continuous positive airway pressure (40.0% versus 27.2%), report significantly reduced sleepiness, and a greater ability to perform daily activities. Moreover, a significantly greater proportion of patients reported a positive experience with sleep testing in the HSAT arm compared with the iPSG arm (89.4% versus 31.1%). Finally, a cost-effectiveness analysis revealed that HSAT was economically attractive for the detection of OSA compared with iPSG. CONCLUSIONS: In patients with stroke/transient ischemic attack, use of HSAT compared with iPSG increases the rate of OSA diagnosis and treatment, reduces daytime sleepiness, improves functional outcomes and experiences with sleep testing, and could be an economically attractive approach. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02454023.

Predictors of in-laboratory polysomnography attendance in a cohort of patients with stroke or TIA.

STUDY OBJECTIVES: After cerebrovascular events, obstructive sleep apnea (OSA) is associated with poor functional outcomes, an increased risk of recurrent stroke, and mortality. Although the significant under-diagnosis of OSA is likely multifactorial in nature, factors associated with attendance at in-laboratory polysomnography (iPSG) are poorly understood. We evaluated demographic, lifestyle, and clinical variables that predicted attendance at iPSG in a cohort of patients with stroke and transient ischemic attack (TIA) enrolled in a clinical research study. METHODS: Demographic, lifestyle, and clinical variables were summarized for the patients who did and did not attend iPSG. Multivariable binary logistic regression analyses were performed to examine four models that thematically aggregated predictors expected to relate to attendance. Further, t-tests for continuous variables, and chi-squared tests for categorical variables, were performed to uncover differences between the two groups. RESULTS: In the 122 participants included in our analyses, mean age was 66.6 ± 15.7 (64.8% males) with only 59.0% of participants attending iPSG. Only Model 1, which investigated the impact of demographic, lifestyle, and cognitive status, was significant (χ2 = 35.31, p < 0.001). Among our variables, (1) younger age, (2) better cognition, (3) higher level of education, and (4) never-smoking status significantly predicted attendance at iPSG. CONCLUSION: By understanding the relationship between variables that significantly predict attendance, we hope our results will translate into practices that promote iPSG attendance, which may help improve outcomes in the stroke/TIA population. CLINICAL TRIALS: SLEep APnea Screening Using Mobile Ambulatory Recorders After TIA/Stroke (SLEAP SMART) (NCT02454023); https://clinicaltrials.gov/ct2/show/NCT02454023.

Predictors of CPAP adherence following stroke and transient ischemic attack.

OBJECTIVE: Continuous positive airway pressure (CPAP) has been shown to improve functional, motor and cognitive outcomes in post-stroke obstructive sleep apnea (OSA). However, rates of CPAP adherence are often low and factors impacting CPAP adherence remain under-explored. Our objective was to determine predictors of CPAP adherence in patients who had a stroke or transient ischemic attack (TIA). METHODS: We screened 313 stroke/TIA patients for OSA using in-hospital polysomnography or the ApneaLink home sleep apnea test. Potential predictors were recorded at baseline and adherence to CPAP was recorded during a six-month follow-up visit. Selected variables from our univariate analyses were included in multivariate regression models to determine predictors of CPAP adherence. For our logistic regression analyses, CPAP adherence (CPAP use of ≥4 h per night) was the dependent outcome variable. In our linear regression analyses, total CPAP use per week (recorded in hours) was the dependent outcome variable. RESULTS: Eighty-eight patients (mean age 67.81 ± 13.09 years, 69.32% male, mean body mass index 27.93 ± 5.23 kg/m2) were diagnosed with OSA, prescribed CPAP, and assessed for adherence at a six-month follow-up visit. In these 88 patients, 46 (52.27%) were adherent with CPAP therapy. From our regression models, two significant predictors of CPAP adherence were identified: greater functional status (p = 0.04) and not endorsing daytime tiredness (p = 0.047) post-stroke/TIA. CONCLUSION: Patients with greater functional capacity and those with less daytime fatigue demonstrated stronger adherence to CPAP therapy. Our findings may facilitate future treatment strategies for enhancing CPAP adherence in the vulnerable stroke/TIA population.

Educating Stroke/TIA Patients about Obstructive Sleep Apnea after Stroke: A Randomized Feasibility Study.

BACKGROUND: Obstructive sleep apnea (OSA) occurs in about 70% of stroke and transient ischemic attack (TIA) patients and is associated with poor function and recurrent vascular events. Continuous Positive Airway Pressure (CPAP) has been shown to improve poststroke/TIA outcomes but adherence is generally poor. This study aimed to develop and conduct a preliminary assessment of educational materials for poststroke/TIA OSA. METHODS: This blinded pilot study involved the randomization of stroke/TIA patients to either an intervention group (who viewed an educational pamphlet and slideshow) or a control group (standard of care). Patient ratings were used to evaluate the educational materials. Changes in knowledge, daytime sleepiness, functional outcomes of sleep, and CPAP use were assessed at baseline and 6 months. RESULTS: Total 93% of eligible patients consented to participate. Forty-eight participants were randomized to the control group (n = 23) or intervention group (n = 25). In the intervention group, all patients agreed or strongly agreed that the information in the educational materials was useful and that the wording was easy to understand. There were no significant changes in knowledge, daytime sleepiness, and functional outcomes of sleep between both groups at 6 months. In those who used CPAP, there was no significant difference in mean hours of CPAP use at the 6-month follow-up. CONCLUSIONS: The educational program was feasible and easy to understand amongst stroke/TIA patients but did not lead to a significant change in outcomes or CPAP use. The lessons learned can be used to facilitate future development of educational materials and plan an adequately-powered trial.

Using a modified version of the "STOP-BANG" questionnaire and nocturnal oxygen desaturation to predict obstructive sleep apnea after stroke or TIA.

PURPOSE: Obstructive sleep apnea (OSA) is a risk factor and common morbidity for stroke and transient ischemic attack (TIA). However, screening for OSA in patients with stroke or TIA is uncommonly performed, due in part to difficulties associated with conducting polysomnography (PSG) and Home Sleep Apnea Tests (HSATs). The 8-point "STOP-BANG" questionnaire has been shown to have high methodological quality in screening for OSA. This study examined the clinical utility of a modified version of the "STOP-BANG" questionnaire, which removed neck circumference and included nocturnal oxygen desaturation in diagnosing OSA (ie, the "STOP-BAG-O" tool), with the goal of improving uptake and accuracy in diagnosing OSA. METHODS: In total, 231 participants completed both the STOP-BAG questionnaire and PSG or HSAT within 12 months of stroke/TIA. Using receiver-operating curves, scores on the "STOP-BAG-O" and "STOP-BAG" questionnaires were assessed for their ability to predict a diagnosis of OSA and classify at least 50% of the study population. RESULTS: Compared to an OSA diagnosis of AHI≥10, the STOP-BAG (using cut-offs of ≤3 and ≥4) had a sensitivity and specificity of 83.5% and 67.2%, respectively. The STOP-BAG-O (using cut-offs of ≤3 and ≥5) had a sensitivity and specificity of 95.9% and 78.4%, respectively. For all AHI cut-offs used, the area under the curve for the STOP-BAG-O was greater and statistically different (p < 0.001) than that for the STOP-BAG. CONCLUSIONS: The STOP-BAG-O is a valid tool for identifying risk of OSA post-stroke/TIA. The simplicity of this tool and ease of assessing nocturnal oxygen desaturation makes it a feasible option for widespread use.

A Modified Definition for Obstructive Sleep Apnea in Home Sleep Apnea Testing after Stroke or Transient Ischemic Attack.

BACKGROUND: Home sleep apnea testing (HSAT) underestimates obstructive sleep apnea (OSA) severity. Overnight oxygen desaturation has been shown to be a strong predictor of incident stroke, and may be helpful in determining which patients with lower apnea-hypopnea indices (AHIs) should be offered treatment. OBJECTIVES: To examine whether a modified definition for OSA that uses oxygen desaturation (i.e., AHI 5-14.9 per hour and lowest O2 desaturation ≤88%), as compared to an AHI ≥ 15 per hour, would impact: (1) changes in Epworth Sleepiness Scale scores post-continuous positive airway pressure (CPAP) initiation; (2) CPAP compliance rates; and (3) the accuracy of automated versus manual scoring of HSAT. METHODS: One hundred and six patients with a prior stroke or transient ischemic attack (TIA) underwent HSAT. Epworth Sleepiness Scale and CPAP compliance were measured at baseline and 3-6 months. RESULTS: Median age was 67.5 years, 57.5% male, and 76.4% presented with stroke. Fifty-nine patients were diagnosed with OSA; of these 54.2% met criteria for the "modified definition" for OSA (AHI 5-14.9 per hour with oxygen desaturation) and 45.8% met criteria for the "classic definition" for OSA (AHI ≥15). The modified (versus classic) definition had: (1) a greater decrease in ESS (P = .05) post-CPAP initiation; (2) comparable CPAP compliance rates; and (3) comparable automatically versus manually scored AHIs (Spearman's rho = .96, Cohen's Kappa ≥ .75 for both definitions, P < .001). CONCLUSIONS: Using a modified definition of OSA that uses a lower AHI cutoff and includes an oxygen desaturation cutoff in the setting of HSAT for stroke or transient ischemic attack (TIA) patients may improve daytime sleepiness post-CPAP initiation, while not significantly affecting CPAP compliance rates nor the accuracy of automated scoring.

Incident Cardiovascular Events and Death in Individuals With Restless Legs Syndrome or Periodic Limb Movements in Sleep: A Systematic Review.

Study Objectives: To systematically review the current evidence examining restless legs syndrome (RLS) and periodic limb movements in sleep (PLMS) as prognostic factors for all-cause mortality and incident cardiovascular events (CVE) in longitudinal studies published in the adult population. Methods: All English language studies (from 1947 to 2016) found through Medline and Embase, as well as bibliographies of identified articles, were considered eligible. Quality was evaluated using published guidelines. Results: Among 18 cohorts (reported in 13 manuscripts), 15 evaluated the association between RLS and incident CVE and/or all-cause mortality and 3 between PLMS and CVE and mortality. The follow-up periods ranged from 2 to 20 years. A significant relationship between RLS and CVE was reported in four cohorts with a greater risk suggested for severe RLS with longer duration and secondary forms of RLS. Although a significant association between RLS and all-cause mortality was reported in three cohorts, a meta-analysis we conducted of the four studies of highest quality found no association (pooled hazard ratio = 1.09, 95% confidence interval: 0.80-1.78). A positive association between PLMS and CVE and/or mortality was demonstrated in all included studies with a greater risk attributed to PLMS with arousals. Conclusions: The available evidence on RLS as a prognostic factor for incident CVE and all-cause mortality was limited and inconclusive; RLS duration, severity, and secondary manifestations may be important in understanding a possible relationship. Although very limited, the current evidence suggests that PLMS may be a prognostic factor for incident CVE and mortality.