ApneaLink Plus Research Articles

Novel metrics of sleep-disordered breathing are associated with outcome after ischemic stroke

Objective/backgroundStandard measures of sleep-disordered breathing (SDB) that rely on count data may not sufficiently capture SDB severity or reflect downstream consequences of SDB. We hypothesized that novel metrics derived from pulse rate, oxygen saturation, and nasal pressure would be associated with stroke outcomes. Patients/methodsShortly after ischemic stroke, participants in a population-based study were offered ApneaLink Plus testing. Signal analysis was used to generate 166 metrics from the nasal pressure cannula and finger probe, categorized as: autonomic (based on pulse rate variability), oximetry-derived, nasal pressure-derived, and mixed oxygen and nasal pressure-derived measures. Three-month outcome assessments included functional and cognitive outcomes and stroke recurrence. Tobit regression and Cox proportional hazards models were used to examine associations between each sleep apnea metric and the three outcomes, unadjusted and adjusted for multiple potential confounders. Models were adjusted for multiple comparisons. ResultsOf the 530 participants, the median age was 65 (IQR: 57, 73), 49 % were female, and 64 % were Mexican American. Without covariate adjustment, 23 of 166 variables were associated with functional outcome, 43 were associated with cognitive outcome, and 1 was associated with stroke recurrence. After adjustment, 7 mixed, oximetry, or nasal pressure-based metrics and 1 autonomic metric were associated with functional outcome, but none was associated with cognitive outcome or stroke recurrence. ConclusionsMany novel metrics of SDB were associated with important stroke outcomes, and 8 novel metrics were associated with functional outcome in adjusted models. This raises hypotheses about pathways by which SDB may negatively impact stroke outcomes.

Longitudinal Assessment of Sleep Apnea in the Year After Stroke in a Population-Based Study.

The aim of this study was to characterize change in sleep-disordered breathing severity in the year following stroke, overall, and by ethnicity, within the population-based Brain Attack Surveillance in Corpus Christi Project. First-ever ischemic strokes (n=414) were ascertained by active and passive surveillance and validated by stroke-trained physicians. Patients with stroke were invited to participate in portable sleep apnea testing (ApneaLink Plus) at baseline and 3, 6, and 12 months poststroke. Sleep-disordered breathing severity was assessed by the respiratory event index (apneas and hypopneas/hour of recording). The component obstructive apnea index and central apnea index were also assessed. Time and ethnicity effects on outcomes, as well as ethnic differences in time effects, were analyzed using generalized estimating equations with multivariable adjustment for confounding factors. Mean age (n=414) was 63.9 years (SD=10.9); 68.4% were Mexican American. Baseline mean respiratory event index, obstructive apnea index, and central apnea index were 21.3 (SD=16.6), 8.6 (SD=11.5), and 1.5 (SD=3.2), respectively. There was no time effect on respiratory event index (P=0.35) but obstructive apnea index increased over time (P<0.01). Averaged over follow-up, respiratory event index and obstructive apnea index were significantly higher in Mexican American than non-Hispanic White persons. No ethnic difference in the time effect was found for either outcome. For central apnea index, there was an ethnicity-time interaction (P=0.01) such that central apnea index increased in non-Hispanic White but did not change in Mexican American persons. Sleep-disordered breathing severity was significant and stable for most individuals in the year after stroke. These results do not confirm previous reports of diminishing sleep-disordered breathing severity over time after stroke and would support early assessment and treatment where indicated.

Abstract TMP108: Improvements In Sleep Apnea Are Associated With Improvements In NIHSS In The First Year After Stroke.

Introduction: Sleep apnea, a very common condition among post-stroke patients, is associated with worse functional, cognitive, and neurological outcomes after stroke. Little is known about the association between change of sleep apnea and changes in outcome over time. Methods: Associated with the Brain Attack Surveillance in Corpus Christi (BASIC) project, ischemic stroke patients (2016-2019) were offered sleep apnea testing with a portable respiratory monitor (ApneaLink Plus) shortly after stroke and at 3, 6, and 12 months post-stroke. Sleep apnea was quantified using the respiratory event index (REI), the number of apneas plus hypopneas per recording hour. At 3, 6, and 12-months post-stroke, functional outcome was assessed using activities of daily living (ADL)/instrumental activities of daily living (IADL) score (1-4, lower better); cognitive outcome was assessed using the Modified Mini-Mental State Examination (3MS) (0-100, higher better); neurological outcome was assessed using the NIHSS (0-42, lower better). Multivariate mixed models were fitted under a Bayesian approach to obtain random slopes in REI over time and the three outcomes (1-unit change in outcome per month), adjusted for age, sex, ethnicity, pre-stroke function and cognitive status, education, marital status, stroke history, tpa use, recurrent stroke, and depression. Linear regression models assessed the association between random slope of REI and random slopes of the three outcomes. Results: Of the 482 Mexican American or non-Hispanic white participants with at least one REI measurement, in fully adjusted models, improvement in sleep apnea was significantly associated with improvement in NIHSS (0.0094 (95% CI: 0.0070, 0.0118)) but not with changes in ADL/IADL or 3MS. Conclusions: Improvement in sleep apnea paralleled improvement in neurological status over the first year after stroke.

Abstract WP75: Association Between Sleep-disordered Breathing And Post-stroke Fatigue

Background: Post-stroke fatigue (PSF) is a common and often disabling symptom, the etiology of which is poorly understood. Sleep-disordered breathing (SDB) is also highly prevalent among stroke survivors. We explored the relationship between SDB and PSF over time in a bi-ethnic cohort. Methods: Ischemic stroke (IS) patients within the Brain Attack Surveillance in Corpus Christi (BASIC) project were identified through active and passive surveillance, and were offered home SDB screening with a well-validated cardiopulmonary sleep apnea testing device, the ApneaLink Plus. The primary exposure was the respiratory event index (REI). The primary outcome was PSF as measured by the SF-36 vitality scale (lower scores reflect greater fatigue). SDB and PSF were measured at baseline, 3, 6, and 12 months post-stroke. A linear regression model, using GEE to account for repeated measures, was used to examine the associations between REI and PSF at each time point adjusting for sociodemographics, stroke severity, depressive symptoms, pre-stroke fatigue, and comorbidities. Results: SDB screening and at least one PSF assessment were completed by 462 IS patients, who were 44% female, 61% Mexican American (MA), 26% non-Hispanic white, 7% Black, and 5% other race/ethnicity. Median NIHSS was 2 (IQR: 1-4). Multivariable regression model results are presented in the Table. Higher REI at 3 months was associated with greater PSF at 3 months (β= -1.87, 95%CI -3.47, -0.27), but there was no association between REI and PSF at 6 or 12 months. Across timepoints, female sex, depressive symptoms at time of assessment, pre-stroke medication for depression, higher levels of pre-stroke fatigue, and vascular risk factor burden were associated with greater PSF, whereas MA ethnicity was associated with less PSF. Conclusions: Higher REI was associated with greater PSF in the early post-stroke period, but no association was observed at 6 months and beyond. MA ethnicity seems to be protective against PSF.

Racial and ethnic differences in sleep-disordered breathing and sleep duration among stroke patients

ObjectiveWe sought to characterize racial and ethnic differences in pre- and post-stroke sleep-disordered breathing (SDB) and pre-stroke sleep duration. MethodsWithin the Brain Attack Surveillance in Corpus Christi cohort of patients with ischemic stroke (8/26/2010-1/31/2020), pre-stroke SDB risk was assessed retrospectively using the Berlin Questionnaire. Post-stroke SDB was defined by prospective collection of the respiratory event index (REI) using the ApneaLink Plus performed shortly after stroke. Pre-stroke sleep duration was self-reported. We used separate regression models to evaluate the association between race/ethnicity and each outcome (pre-stroke SDB, post-stroke SDB, and pre-stroke sleep duration), without and with adjustment for potential confounders. ResultsThere was no difference in pre-stroke risk of SDB between Black and non-Hispanic white (NHW) participants (odds ratio (OR) 1.07, 95% CI 0.77-1.49), whereas MA (Mexican American), compared to NHW, participants had a higher risk of SDB before adjusting for demographic and clinical variables (OR 1.26, 95% CI 1.08-1.47). Post-stroke SDB risk was higher in MA (estimate 1.16, 95% CI 1.06-1.28) but lower in Black (estimate 0.79, 95% CI 0.65-0.96) compared to NHW participants; although, only the ethnic difference remained after adjustment. MA and Black participants had shorter sleep duration than NHW participants (OR 0.83, 95% CI 0.72-0.96 for MA; OR 0.67, 95% CI 0.49-0.91 for Black participants) before but not after adjustment. ConclusionsRacial/ethnic differences appear likely to exist in pre- and post-stroke SDB and pre-stroke sleep duration. Such differences might contribute to racial/ethnic disparities in stroke incidence and outcomes.

0710 Validation of the Predictive Utility of the Multivariable Apnea Index for Obstructive Sleep Apnea in Women

Abstract Introduction The Multivariable Apnea Prediction (MAP) index is a commonly used screening tool for obstructive sleep apnea (OSA). Previous analyses have demonstrated higher sensitivity of the MAP in predicting OSA in men versus women and in post-menopausal versus pre-menopausal women with type 2 diabetes (T2DM) and an apnea-hypopnea index (AHI) ≥10. The purpose of this secondary analysis was to validate previous findings by comparing women with and without T2DM across all categories of OSA severity including mild (AHI ≥5). Methods The sample (N=386) was comprised of participants from the Diabetes Sleep Treatment Trial who were recruited because of risk for OSA with T2DM (n=279), and the EMPOWER study which examined triggers for lapses or relapse after intentional weight loss in overweight but otherwise healthy participants (n=115). AHI was assessed by in-home sleep study, ApneaLink Plus®. Descriptive statistics and binomial logistic regression and receiver operating characteristic analyses were conducted to evaluate classification of OSA diagnosis, defined as AHI ≥5 or ≥10, by MAP between sexes and by menopause status. Results Participants were middle aged (mean 54.09 years + 10.63), obese (mean BMI of 34.79 + 6.52 kg/m2), primarily female (67%), and white (64%). Compared to men, women were younger (52.99 years + 10.15 vs. 56.26 years + 11.25, p=0.004) and had a lower AHI (9.10 + 18.94 vs. 17.25 + 18.94, p&amp;lt;0.001). No significant differences, except for age, were noted between pre- and post-menopausal women. Sensitivity of MAP on OSA diagnosis was higher for men than women (AHI ≥5: 94.7% vs. 76%; AHI ≥10: 84.2% vs 29.6%). Sensitivity of MAP on OSA diagnosis was lower for pre-menopausal than post-menopausal women using AHI ≥5 (74.0% vs. 98.8%) and AHI ≥10 (19.0% vs. 32.1%). Conclusion This validation study corroborates previous findings that the MAP index was better at identifying OSA in men than women, and in post- versus pre-menopausal women using AHI values across all categories of OSA severity. Improved screening methods are needed to detect women at high risk for OSA. Support (If Any) This study was funded by the National Institutes of Health (R01-DK090628, R01-HL107370).

Overnight Rostral Fluid Shifts Exacerbate Obstructive Sleep Apnea After Stroke.

Overnight shifts of fluid from lower to upper compartments exacerbate obstructive sleep apnea (OSA) in some OSA populations. Given the high prevalence of OSA after stroke, decreased mobility and use of IV fluids among hospitalized patients with stroke, and improvement in OSA in the months after stroke, we hypothesized that overnight fluid shifts occur and are associated with OSA among patients with subacute ischemic stroke. Within a population-based project, we performed overnight sleep apnea tests (ApneaLink Plus) during ischemic stroke hospitalizations. Before sleep that evening, and the following morning before rising from bed, we assessed neck and calf circumference, and leg fluid volume (bioimpedance spectroscopy). The average per subject overnight change in the 3 fluid shift measurements was calculated and compared with zero. Linear regression was used to test the crude association between each of the 3 fluid shift measurements and the respiratory event index (REI). Among the 292 participants, mean REI was 24 (SD=18). Within individuals, calf circumference decreased on average by 0.66 cm (SD=0.75 cm, P<0.001), leg fluid volume decreased by a mean of 135.6 mL (SD=132.8 mL, P<0.001), and neck circumference increased by 0.20 cm (SD=1.71 cm, P=0.07). In men, when the overnight change of calf circumference was negative, an interquartile range (0.8 cm) decrease in calf circumference overnight was significantly associated with a 25.1% increase in REI (P=0.02); the association was not significant in women. The relationship between overnight change in leg fluid volume and REI was U shaped. This population-based, multicenter, cross-sectional study showed that in hospitalized patients with ischemic stroke, nocturnal rostral fluid shifts occurred, and 2 of the 3 measures were associated with greater OSA severity. Interventions that limit overnight fluid shifts should be tested as potential treatments for OSA among patients with subacute ischemic stroke.

Predictive performance of oximetry in detecting sleep apnea in surgical patients with cardiovascular risk factors.

In adults with cardiovascular risk factors undergoing major noncardiac surgery, unrecognized obstructive sleep apnea (OSA) was associated with postoperative cardiovascular complications. There is a need for an easy and accessible home device in predicting sleep apnea. The objective of the study is to determine the predictive performance of the overnight pulse oximetry in predicting OSA in at-risk surgical patients. This was a planned post-hoc analysis of multicenter prospective cohort study involving 1,218 at-risk surgical patients without prior diagnosis of sleep apnea. All patients underwent home sleep apnea testing (ApneaLink Plus, ResMed) simultaneously with pulse oximetry (PULSOX-300i, Konica Minolta Sensing, Inc). The predictive performance of the 4% oxygen desaturation index (ODI) versus apnea-hypopnea index (AHI) were determined. Of 1,218 patients, the mean age was 67.2 ± 9.2 years and body mass index (BMI) was 27.0 ± 5.3 kg/m2. The optimal cut-off for predicting moderate-to-severe and severe OSA was ODI ≥15 events/hour. For predicting moderate-to-severe OSA (AHI ≥15), the sensitivity and specificity of ODI ≥ 15 events per hour were 88.4% (95% confidence interval [CI], 85.7-90.6) and 95.4% (95% CI, 94.2-96.4). For severe OSA (AHI ≥30), the sensitivity and specificity were 97.2% (95% CI, 92.7-99.1) and 78.8% (95% CI, 78.2-79.0). The area under the curve (AUC) for moderate-to-severe and severe OSA was 0.983 (95% CI, 0.977-0.988) and 0.979 (95% CI, 0.97-0.909) respectively. ODI from oximetry is sensitive and specific in predicting moderate-to-severe or severe OSA in at-risk surgical population. It provides an easy, accurate, and accessible tool for at-risk surgical patients with suspected OSA.

Abstract P597: Growing Prevalence of Post-Stroke Sleep-Disordered Breathing

Introduction: Sleep-disordered breathing (SDB) is common after stroke and is associated with poor functional and cognitive outcomes, and recurrent stroke. Despite increasing prevalence of SDB in the general population, no data are available about trends in post-stroke SDB. We therefore sought to assess changes in post-stroke SDB prevalence over a 10-year period. Methods: Within the Brain Attack Surveillance In Corpus Christi (BASIC) project, a population-based stroke surveillance study in south Texas, participants with acute ischemic stroke were offered assessment of SDB with the ApneaLink Plus device. Medical record abstraction and baseline interviews were conducted and included the Berlin questionnaire to assess SDB status in reference to the prestroke state. SDB testing was performed shortly after stroke presentation (median 12 days (IQR: (6, 21)). Respiratory event index (REI) was calculated as the sum of apneas and hypopneas per hour of overnight recording. SDB was defined as an REI ≥10. SDB assessment procedures remained unchanged throughout (2010-2020). Logistic (SDB) and linear (REI) regression were used to test associations with time (parameterized as years since 2010) adjusted for demographics, and stroke and SDB risk factors including BMI and pre-stroke SDB status. Results: Among the 1,197 participants, median age was 65, 53% were male, and 65% were Mexican American. SDB prevalence was 61% in 2010-2011 and 75% in 2018-2019. Median REI was 19 in 2010-2011 and 23 in 2018-2019. A linear association was identified between time and SDB (REI≥10), with an odds ratio of 1.123 (95% CI: 1.062, 1.187) per year, after adjustment. Similarly, a linear association was identified between time and REI, with an average increase of 0.504 (95% CI: 0.148, 0.860) per year, after adjustment. Based on models with interaction terms added, no differences in time trends were found by sex or ethnicity. Conclusions: Post-stroke SDB prevalence in this population-based sample has increased over the last 10 years. These data highlight the importance of post-stroke SDB and the pressing need to determine whether its treatment improves outcomes.

Acute Altitude Acclimatization in Young Healthy Volunteers: Nocturnal Oxygenation Increases Over Time, Whereas Periodic Breathing Persists.

Ju, Jia-Der, Cristian Zhang, Francis P. Sgambati, Lidia M. Lopez, Luu V. Pham, Alan R. Schwartz, and Roberto A. Accinelli. Acute altitude acclimatization in young healthy volunteers: nocturnal oxygenation increases over time whereas periodic breathing persists. High Alt Med Biol. 22:14-23, 2021. Study Objectives: This study aimed to examine the acute effects of high altitude (HA) on sleep disordered breathing (sleep apnea and nocturnal hypoxemia) and acute mountain sickness and to characterize acclimatization over time. Methods: Ten native lowlanders residing at sea level (SL) completed the Lake Louise Score (LLS) and underwent nocturnal polygraphy (ApneaLink Plus) for nine consecutive nights (N1-N9) at HA (2,761 m) and two nights before and after HA. Nocturnal oxygen profiles were assessed by measuring the mean nocturnal oxyhemoglobin saturation (SpO2) during sleep, and sleep apnea severity as assessed by measuring the Apnea-Hypopnea Index (AHI). Mixed-effects linear regression was used to model responses in outcomes (mean nocturnal SpO2, logAHI, and LLS) between HA and SL. Changes in SpO2 and AHI were examined in subgroups with mild versus marked nocturnal SpO2 and low versus high AHI during exposure to HA and compared between subgroups. Results: Compared with SL, the mean nocturnal SpO2 was lower (p < 0.0001) and AHI was higher (p < 0.0001) at HA. The mean nocturnal SpO2 increased progressively (p < 0.001), whereas AHI remained high (p < 0.978) and relatively unchanged over nine successive nights at HA. Those with markedly reduced SpO2 upon arrival at HA exhibited progressive increases in the mean nocturnal SpO2 over time at HA compared with those with mild nocturnal desaturation. LLS rose at HA, but no differences were observed between subgroups. Conclusions: In healthy HA sojourners, the mean nocturnal SpO2 increased progressively over time, whereas AHI remained elevated, suggesting distinctive phenotypes and acclimatization responses to HA.

Prognostic relevance of sleep apnea syndrome in patients with pulmonary arterial hypertension

Abstract Introduction Sleep disordered breathing (SDB) is a group of ventilatory disorders during sleep which includes obstructive sleep apnea (OSA), central sleep apnea (CSA), and sleep related hypoventilation. In patients with SDB, the prevalence of pulmonary hypertension (PH) ranges from 17% to 52%. While SDB is prevalent in the general population with recent estimates of 20% to 30%, in those with cardiovascular disease, particularly left ventricular failure, there is a higher reported prevalence of 47%. Aims The aims of this study were to determine the prevalence and prognostic relevance of sleep apnea in a cohort of patients with newly diagnosed pulmonary arterial hypertension (ESC/WHO Group 1 pulmonary hypertension). Methods We evaluated prospectively 76 patients with the pulmonary arterial hypertension (mean age 54±16 years; 45% male). All patients underwent right heart catheterisation, clinical assessments, sleep study, standard laboratory testing and evaluation of subjective sleepiness by the Epworth Sleepiness Scale. Sleep test was provided with an ApneaLink Plus, consisting of nasal pressure sensor, respiratory effort band, and pulse oximeter worn on the finger. Subjects previously treated for or diagnosed with SDB were excluded from the study. Results Sleep apnea (SA) – defined as apnea-hypopnea index (AHI) ≥5/h – was found in 59 (77.6%) of the pulmonary arterial hypertension (PAH) patients. Mean AHI in the cohort of PAH patients with SA was 26.1±16.6/h. Mean follow-up was 24 months, during which 15 (19.7%) patients died. Characteristics of parameters related to SA in groups of survivors and deceased are in table 1. From the sleep apnea-related parameters, only time with O2Sat &amp;lt;90% – T90 was significantly associated with mortality (AUC 0.856; 95% CI 0.693 – 1.019; p&amp;lt;0.001). Conclusions The presence of sleep apnea in pulmonary arterial hypertension patients is high. The prevalence of sleep apnea is higher in PAH patients than in the general population. The presence of sleep apnea in patients with PAH was not associated with worse prognosis, but noctural hypoxemia (time with O2Sat &amp;lt;90%) was related to poor prognosis. Sleep apnea in patients with PAH should be screened for systematically. Funding Acknowledgement Type of funding source: None

Abstract WP216: Predicting Sleep Apnea After Ischemic Stroke

Introduction: Sleep apnea (SA) is highly prevalent after stroke and is associated with poor stroke outcomes. Currently, after stroke, a physiological test must be used to differentiate patients with and without SA. Within a large, population-based study, we tested the usefulness of statistical models based on baseline characteristics to predict SA. Methods: Within the Brain Attack Surveillance in Corpus Christi (BASIC) project, participants with ischemic stroke (2010-2018) underwent SA screening, shortly after stroke, with the ApneaLink Plus portable sleep apnea testing device. The respiratory event index (REI) was calculated as the number of apneas and hypopneas per hour of recording; values ≥10 defined SA. Logistic regression and the Distributed Random Forest Classifier (a machine learning technique) were applied to predict SA with the following as predictors: demographics, stroke risk factors, stroke severity (NIHSS), neck and waist circumference, palate position, and pre-stroke symptoms of snoring, apneas, and sleepiness. Models were internally validated with cross-validation. Results: Within the total sample (n=1,330), median age was 65; 47% were women; 32% non-Hispanic white, 62% Mexican American, and 6% African American. SA was found in 67%. The area under the receiver operating characteristic curve, a measure of predictive ability, applied to the validation sample, was 0.69 for logistic regression and 0.74 for the random forest model. Random forest correctly classified 72.3% of validation samples, while logistic regression correctly classified 70.7% of validation samples. The most important features for predicting SA were waist circumference, neck circumference, body mass index, NIHSS, and pre-stroke daytime sleepiness. Conclusions: In this large, ethnically diverse, population-based sample of ischemic stroke patients, prediction models based on easily obtained baseline characteristics and simple measurements resulted in fair performance, despite use of advanced statistical and machine learning techniques. Physiological tests are still needed to differentiate ischemic stroke patients with and without SA.

Sleep-disordered breathing and poststroke outcomes.

To examine the association between sleep-disordered breathing and stroke outcomes, and determine the contribution of sleep-disordered breathing to outcome disparities in Mexican Americans. Ischemic stroke patients (n = 995), identified from the population-based Brain Attack Surveillance in Corpus Christi Project (2010-2015), were offered participation in a sleep-disordered breathing study including a home sleep apnea test (ApneaLink Plus). Sleep-disordered breathing (respiratory event index ≥10) was determined soon after stroke. Neurologic, functional, cognitive, and quality of life outcomes were assessed at 90 days poststroke. Regression models were used to assess associations between sleep-disordered breathing and outcomes, adjusted for sociodemographics, prestroke function and cognition, health-risk behaviors, stroke severity, and vascular risk factors. Median age was 67 years (interquartile range [IQR] = 59-78); 62.1% were Mexican American. Median respiratory event index was 14 (IQR = 6-25); 62.8% had sleep-disordered breathing. Sleep-disordered breathing was associated with worse functional outcome (mean difference in activities of daily living/instrumental activities of daily living score = 0.15, 95% confidence interval [CI] = 0.01-0.28) and cognitive outcome (mean difference in modified Mini-Mental State Examination = -2.66, 95% CI = -4.85 to -0.47) but not neurologic or quality of life outcomes. Sleep-disordered breathing accounted for 9 to 10% of ethnic differences in functional and cognitive outcome and was associated with cognitive outcome more strongly for Mexican Americans (β = -3.97, 95% CI = -6.63 to -1.31) than non-Hispanic whites (β = -0.40, 95% CI = -4.18 to 3.39, p-interaction = 0.15). Sleep-disordered breathing is associated with worse functional and cognitive function at 90 days poststroke. These outcomes are reasonable endpoints for future trials of sleep-disordered breathing treatment in stroke. If effective, sleep-disordered breathing treatment may somewhat lessen ethnic stroke outcome disparities. ANN NEUROL 2019;86:241-250.

Do apneas and hypopneas best reflect risk for poor outcomes after stroke?

Objective/BackgroundSleep apnea (SA) is associated with poor outcomes after stroke. The best sleep apnea-related measure to capture this relationship is currently unknown. This measure or its underlying pathophysiology could serve as a treatment target. Patients/MethodsWithin the population-based Brain Attack Surveillance in Corpus Christi (BASIC) project, the ApneaLink Plus was used to perform sleep apnea tests shortly after ischemic stroke (2010–2015). Functional and cognitive outcomes were measured via in-person interviews 90-days post-stroke. Recurrent stroke was assessed longitudinally through active and passive surveillance procedures. After standardization to allow direct comparisons, adjusted models were built for each ApneaLink Plus measure and each outcome, to assess the effect of 1 standard deviation difference in the measure. ResultsAmong 995 subjects, median age was 67 years (interquartile range: 59, 78) and 52% were women. The respiratory event index had the strongest relationship with functional outcome (mean difference = 0.094, 95% confidence interval (CI): 0.040, 0.147). Desaturations ≤85% were associated with worse functional outcome (mean difference = 0.016, 95% CI: 0.002, 0.030), but desaturations ≤ 90% were not. Obstructive apnea index (OAI) showed the strongest association with cognitive outcome (mean difference = −0.079, 95% CI: −0.162, 0.005), but was not significant. Oxygen desaturation index (ODI) showed the strongest association with recurrent ischemic stroke (hazard ratio = 1.338, 95% CI: 1.016, 1.759). ConclusionsMeasurements easily obtained from a commonly used home sleep apnea test predicted outcomes differentially. This suggests the possibility of different SA-associated targets (perhaps using strategies more tolerable than standard treatment) based on the outcome of interest.

Sleep-Disordered Breathing Is Associated With Recurrent Ischemic Stroke.

Background and Purpose- Limited data are available about the relationship between sleep-disordered breathing (SDB) and recurrent stroke and mortality, especially from population-based studies, large samples, or ethnically diverse populations. Methods- In the BASIC project (Brain Attack Surveillance in Corpus Christ), we identified patients with ischemic stroke (2010-2015). Subjects were offered screening for SDB with the ApneaLink Plus device, from which a respiratory event index (REI) score ≥10 defined SDB. Demographics and baseline characteristics were determined from chart review and interview. Recurrent ischemic stroke was identified through active and passive surveillance. Cause-specific proportional hazards models were used to assess the association between REI (modeled linearly) and ischemic stroke recurrence (as the event of interest), and all-cause poststroke mortality, adjusted for multiple potential confounders. Results- Among 842 subjects, the median age was 65 (interquartile range, 57-76), 47% were female, and 58% were Mexican American. The median REI score was 14 (interquartile range, 6-26); 63% had SDB. SDB was associated with male sex, Mexican American ethnicity, being insured, nonsmoking status, diabetes mellitus, hypertension, lower educational attainment, and higher body mass index. Among Mexican American and non-Hispanic whites, 85 (11%) ischemic recurrent strokes and 104 (13%) deaths occurred, with a median follow-up time of 591 days. In fully adjusted models, REI was associated with recurrent ischemic stroke (hazard ratio, 1.02 [hazard ratio for one-unit higher REI score, 95% CI, 1.01-1.03]), but not with mortality alone (hazard ratio, 1.00 [95% CI, 0.99-1.02]). Conclusions- Results from this large population-based study show that SDB is associated with recurrent ischemic stroke, but not mortality. SDB may therefore represent an important modifiable risk factor for poor stroke outcomes.

Abstract TP215: Clinical Phenotypes of Obstructive Sleep Apnea in Stroke Patients: A Cluster Analysis

Introduction: Obstructive sleep apnea (OSA) is highly prevalent in stroke survivors. Untreated OSA is associated with an increased risk of adverse cardiovascular outcomes and OSA treatment may improve neurological recovery in stroke survivors, yet OSA in stroke patients remains poorly characterized. To our knowledge, this is the first study aiming to identify OSA phenotypes in stroke survivors. Methods: Patients (n=451) with ischemic strokes and OSA (apnea-hypopnea index (AHI) ≥ 10 using a cardiopulmonary screening device (ApneaLink Plus)) were identified from the Brain Attack Surveillance in Corpus Christi (BASIC) project. Latent class analysis was performed based on the following variables: age, sex, race/ethnicity, AHI, pre-stroke snoring, pre-stroke tiredness/fatigue, pre-stroke sleep duration, prior stroke history, initial NIHSS, BMI, hypertension, diabetes, atrial fibrillation, coronary artery disease, and congestive heart failure. Results: A model with 3 phenotype clusters provided the best fit. Cluster 1 (n=55, 12%) was defined by higher NIHSS scores and high prevalence of snoring. Patients in cluster 2 (n=253, 56%) were younger and had relatively low NIHSS scores. Cluster 3 (n=143, 32%) included patients with severe OSA and higher prevalence of medical comorbidities. Conclusion: Ischemic stroke survivors with OSA can be categorized into three clinical phenotype clusters characterized by differences in stroke severity, OSA severity, patient age and medical comorbidities. This highlights the heterogeneity of post-stroke OSA. Awareness of the different faces of OSA in patients with ischemic stroke may help clinicians identify OSA in their patients, and informs research concerning the pathophysiology and prognostication of post-stroke OSA.

Abstract TP179: Selecting an Outcome for Sleep Apnea Treatment Trials in Stroke: A Comparative Analysis

Introduction: Post-stroke sleep apnea (SA) affects the majority of stroke patients and is associated with poorer stroke outcomes. To select appropriate endpoints for a future SA treatment trial in stroke patients, we assessed the predictive ability between a variety of important outcome measures and SA severity, as measured by the apnea-hypopnea index (AHI), within a population-based stroke study. Methods: Ischemic stroke patients enrolled in the Brain Attack Surveillance in Corpus Christi (BASIC) project were offered SA screening shortly after stroke with a portable sleep apnea test (ApneaLink Plus). Apnea-hypopnea index (AHI) was calculated as the sum of apneas and hypopneas during the nocturnal recording. Subjects had baseline information collected from chart abstraction and interview, and had 3-month outcomes assessed in-person including an activities of daily living (ADL)/instrumental ADL(IADL) scale, NIHSS, Modified Mini-Mental State exam (3MS), and 12-item Stroke-specific Quality of Life scale (SSQOL). Predictive R 2 (a measure of how well models predict responses for new observations) from linear regression models was used to compare predictive ability of models with and without AHI, adjusted for significant predictors of outcome. Results: Within 455 subjects, the predictive R 2 was 31.7% for ADL/IADL, 23.2% for SSQOL, 25.0% for the 3MS, and 11.7% for NIHSS in the model without AHI. When AHI was included in the models, the predictive R 2 increased to 32.8% for ADL/IADL and increased to 11.9% for NIHSS; however, the predictive R 2 decreased by 0.1% for SSQOL and decreased by 0.2% for 3MS. Conclusions: In future trials that test SA treatment’s effect on stroke outcomes at 3 months, improvement is most likely to be observed from a functional outcome, such as that measured by the ADL/IADL scale.

CORRELATION OF OBSTRUCTIVE SLEEP APNOEA AND ARTERIAL STIFFNESS AS CARDIOLOGIC RISK FACTORS

Objective: The presence of hypertension is a very well stabilished risk factor for the development of future cardiovascular complications, such as AMI and stroke. Recent data suggest a strong association of arterial stiffness as a new risk factor for cardiovascular disease. The presence of obstructive sleep apnea has a strong association with hypertension, especially on those with resistant hypertension. The aim of this study was to evaluate the association of obstructive sleep apnea and arterial stiffness as risk factors for future cardiovascular events in a population of patientes at a hypertension clinic. Design and method: We evaluated 14 patients at a private hypertension clinic using a home sleep test with a class 3 device type Resmed Apnealink Plus and an office assessment of arterial stiffness with Mobil O’Graph device and registered pulse wave velocity and Augmentation Index @75bpm. to observe the coexistence of obstructive sleep apnea and elevated pulse wave analyses, probably due to increased arterial stiffness. The data were analysed, including a subanalyses of the population according to BMI sex, and age. Results: The group consisted of 14 patients. 21,4% were female, with age ranging from 33 to 80 years old (average of 55,13 +−13). The average BMI was 28,9 +−5. 4 patients had mild obstructive sleep apnea (OSA), 5 had moderate OSA and 5 had severe OSA. 8 patients had type 2 D. mellitus. The mean pulse wave velocity was 8,05+−1,7, ranging from 5,8 to 11,4 m/s. The mean systolic central arterial pressure was 131,2 +−15 mmHg and 84,8 +−15 mmHg for diastolic central arterial pressure. In the subgroup with severe sleep obstructive apnea, the mean pulse wave analysis was 8,52 and apneia-hipopneia index was 49,6. There was no straight relationship of elevated apneia-hipopneia index and increased pulse wave velocity, representing increased arterial stiffness, including in the subgroup of diabetec patients. Conclusions: Despite the presence of obstructive sleep apnea and increased arterial stiffness are both considered strong predictors of cardiovascular events, we found no correlation between these 2 findings in the studied population at the same time.

The Effects of Sleeping With or Without Prostheses on Sleep Quality, Sleep Bruxism, and Signs of Obstructive Sleep Apnea Syndrome: A Pilot Study.

To evaluate the effects of sleeping with or without a maxillary mucosa-supported complete denture (CD) in edentulous patients wearing a mandibular fixed implant-supported CD on sleep quality, sleep bruxism (SB) activity, and signs of obstructive sleep apnea syndrome (OSAS). A total of 18 female patients with maxillary mucosa-supported CDs opposing mandibular fixed implant-supported CDs were selected and tested for sleep quality, SB activity, and signs of OSAS during one night while wearing the maxillary CD and another night without wearing it, with a washout period of 7 days in between. The validated Brazilian Portuguese versions of the Pittsburgh Sleep Quality Index (PSQI-BR), Sleep Assessment Questionnaire (SAQ), and Epworth Sleepiness Scale (ESSBR) were used to assess subjective sleep quality. Diagnosis of OSAS followed the American Academy of Sleep Medicine (AASM) guidelines and was confirmed with an objective and validated type 3 portable cardiorespiratory monitor (ApneaLink Plus v.9.00) by measuring the respiratory disturbance index (RDI). SB activity was assessed with a subjective self-report questionnaire and an objective and validated portable electromyographic device (BiteStrip). The objective measurements of SB activity and the RDI showed significant reduction (ie, improvement) when patients did not wear the maxillary CD. The subjective measurements of sleep quality and self-reports of SB activity showed no significant differences between wearing and not wearing a maxillary CD. The present results have shown that not wearing a maxillary CD at night is preferable as far as SB and OSAS are concerned, but larger-scale studies are still needed.

Intracerebral hemorrhage and sleep-disordered breathing

Objective/BackgroundLimited data are available on sleep-disordered breathing (SDB) following intracerebral hemorrhage (ICH). Our aim was to characterize the objective measures of post-ICH SDB and questionnaire-reported pre-ICH sleep characteristics, overall and by ethnicity. Patients/MethodsParticipants with ICH who were enrolled in the population-based Brain Attack Surveillance in Corpus Christi project (2010–2016) reported their pre-ICH sleep duration and completed the Berlin Questionnaire to characterize pre-ICH risk of SDB. A subsample was screened for SDB (respiratory event index ≥10) using ApneaLink Plus portable monitoring. Ethnic differences in post-ICH SDB or questionnaire-reported pre-ICH sleep characteristics were assessed using a log binomial model or a linear regression model or a Fisher's exact test. ResultsICH cases (n = 298) were enrolled (median age = 68 years, 67% Mexican American). Among 62 cases with complete ApneaLink data, median time to post-ICH SDB screening was 11 days (IQR: 6, 19). Post-ICH SDB prevalence was 46.8% (95% CI: 34.4–59.2), and this rate did not differ by ethnicity (p = 1.0). Berlin Questionnaires for 109 of the 298 ICH cases (36.6% (95% CI: 31.1–42.0)) suggested a high risk for pre-ICH SDB, and the median pre-ICH sleep duration was eight hours (IQR: 6, 8). After adjusting for confounders, there was no difference in ethnicity in high risk for pre-ICH SDB or pre-ICH sleep duration. ConclusionsNearly half of the patients had objective confirmation of SDB after ICH, and more than one-third had questionnaire evidence of high risk for pre-ICH SDB. Opportunities to address SDB may be common both before and after ICH.