Prevalence of sleep-disordered breathing and continuous positive airway pressure compliance: results in chinese patients with first-ever ischemic stroke

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Sleep and Stroke: Opening Our Eyes to Current Knowledge of a Key Relationship

PURPOSE OF REVIEW

To elucidate the interconnection between sleep and stroke.

RECENT FINDINGS

Growing data support a bidirectional relationship between stroke and sleep. In particular, there is strong evidence that sleep-disordered breathing plays a pivotal role as risk factor and concur to worsening functional outcome. Conversely, for others sleep disorders (e.g., insomnia, restless legs syndrome, periodic limb movements of sleep, REM sleep behavior disorder), the evidence is weak. Moreover, sleep disturbances are highly prevalent also in chronic stroke and concur to worsening quality of life of patients. Promising novel technologies will probably allow, in a near future, to guarantee a screening of commonest sleep disturbances in a larger proportion of patients with stroke. Sleep assessment and management should enter in the routinary evaluation of stroke patients, of both acute and chronic phase. Future research should focus on the efficacy of specific sleep intervention as a therapeutic option for stroke patients.

Effect of Weight Loss and CPAP on OSA and Metabolic Profile Stratified by Craniofacial Phenotype: A Randomized Clinical Trial

RATIONALE

Craniofacial structure is thought to modulate the effect of weight loss on OSA, but whether this affects metabolic profile after weight loss compared with continuous positive airway pressure(CPAP) is unknown among obese Chinese patients with obstructive sleep apnea(OSA).

OBJECTIVES

To compare the change in metabolic profile between lifestyle modification program(LMP), stratified by craniofacial phenotype, and CPAP therapy for 6 months.

METHODS

We randomly assigned 194 patients with BMI≥25kg/m2 and moderate-to-severe OSA to receive LMP or CPAP therapy for 6 months in a 2:1 ratio. Assessments included computed tomography for assessing maxillomandibular volume(MMV), high sensitivity C-reactive protein(hsCRP) and insulin sensitivity. Measurements and Main Results(mean±SD or median[interquartile range]): Among 128 and 66 subjects in LMP group and CPAP group, respectively, hsCRP reduced more in LMP group than the CPAP group (-0.7[-1.4 to -0.0]mg/L vs -0.3[-0.9 to 0.4]mg/L, p=0.012). More patients in LMP group achieved low hsCRP(<1mg/L) than the CPAP group(21.1% vs 9.1%, p=0.04). Insulin sensitivity improved only in LMP group with 3.1(95%CI 1.5-6.6) times more patients with normal glucose regulation after intervention. LMP group was stratified into LMP-small MMV(n=64) and LMP-large MMV(n=64) groups according to the median MMV value of 233.2cm3. There was no significant difference in hsCRP(-0.7[-1.3 to 0.1] vs -0.7[-1.5 to -0.2], p=0.884) and insulin sensitivity(0.5[-0.2 to 1.9] vs 0.6[0.1 to 2.0], p=0.4860) between LMP-small and LMP-large MMV groups.

CONCLUSION

Weight reduction improved subclinical inflammation and insulin sensitivity more than CPAP among obese Chinese patients with moderate to severe OSA, and this effect was not influenced by craniofacial structure. Clinical trial registration available at www.clinicaltrials.gov, ID: NCT03287973.

Sleep-disordered breathing and ventilatory chemosensitivity in first ischaemic stroke patients: a prospective cohort study

RATIONALE

Sleep-disordered breathing (SDB) is highly prevalent after stroke. The clinical and ventilatory chemosensitivity characteristics of SDB, namely obstructive, central and coexisting obstructive and central sleep apnoea (coexisting sleep apnoea) following stroke are poorly described.

OBJECTIVE

To determine the respective clinical and ventilatory chemosensitivity characteristics of SDB at least 3 months after a first ischaemic stroke.

METHODS

Cross-sectional analysis of a prospective, monocentric cohort conducted in a university hospital. 380 consecutive stroke or transient ischaemic attack patients were screened between December 2016 and December 2019.

MEASUREMENTS AND MAIN RESULTS

Full-night polysomnography, and hypercapnic ventilatory response were performed at a median (Q1; Q3) time from stroke onset of 134.5 (97.0; 227.3) days. 185 first-time stroke patients were included in the analysis. 94 (50.8%) patients presented no or mild SDB (Apnoea-Hypopnoea Index <15 events/hour of sleep) and 91 (49.2%) moderate to severe SDB, of which 52 (57.1%) presented obstructive sleep apnoea and 39 (42.9%) coexisting or central sleep apnoea. Obstructive sleep apnoea patients significantly differed regarding their clinical presentation from patients with no or mild SDB, whereas there was no difference with coexisting and central sleep apnoea patients. The latter presented a higher frequency of cerebellar lesions along with a heightened hypercapnic ventilatory response compared with no or mild SDB patients.

CONCLUSION

SDB in first-time stroke patients differ in their presentation by their respective clinical traits and ventilatory chemosensitivity characteristics. The heightened hypercapnic ventilatory response in coexisting and central sleep apnoea stroke patients may orientate them to specific ventilatory support.

Cardiovascular Disease in Patients with Chronic Obstructive Pulmonary Disease, Obstructive Sleep Apnoea Syndrome and Overlap Syndrome

Chronic obstructive pulmonary disease (COPD) and obstructive sleep apnoea syndrome (OSAS) are among the most prevalent chronic respiratory disorders. Accumulating data suggest that there is a significant burden of cardiovascular disease (CVD) in patients with COPD and OSAS, affecting negatively patients' quality of life and survival. Overlap syndrome (OS), i.e. the co-existence of both COPD and OSAS in the same patient, has an additional impact on the cardiovascular system multiplying the risk of morbidity and mortality. The underlying mechanisms for the development of CVD in patients with either OSAS or COPD and OS are not entirely elucidated. Several mechanisms, in addition to smoking and obesity, may be implicated, including systemic inflammation, increased sympathetic activity, oxidative stress and endothelial dysfunction. Early diagnosis and proper management of these patients might reduce cardiovascular risk and improve patients' survival. In this review, we summarize the current knowledge regarding epidemiological aspects, pathophysiological mechanisms and present point-to-point specific associations between COPD, OSAS, OS and components of CVD, namely, pulmonary hypertension, coronary artery disease, peripheral arterial disease and stroke.

Continuous Positive Airway Pressure Does Not Improve Nonalcoholic Fatty Liver Disease in Patients with Obstructive Sleep Apnea. A Randomized Clinical Trial

Rationale: Obstructive sleep apnea (OSA) is associated with development of nonalcoholic fatty liver disease (NAFLD). The effects of continuous positive airway pressure (CPAP) on NAFLD in patients with concomitant OSA are unknown.Objectives: To investigate the effects of autoadjusting CPAP versus subtherapeutic CPAP treatment over 6 months on NAFLD activities.Methods: Patients with NAFLD and OSA, as defined by respiratory event index ≥5/h diagnosed by a validated level 3 Embletta device, were randomized into group A) autoadjusting CPAP (4-20 cm H₂O) or group B) subtherapeutic CPAP (pressure fixed at 4 cm H₂O). The primary endpoint was the difference in changes in intrahepatic triglyceride as measured by proton magnetic resonance spectroscopy after 6 months of therapy. Key secondary endpoints included changes in controlled attenuation parameter (CAP) and liver stiffness measurement measured with transient elastography, and serum cytokeratin-18 fragment.Measurements and Main Results: A total of 120 patients were randomized equally into two groups. There were significant correlations between CAP and respiratory event index (r = 0.203, P = 0.026), percentage of total recording time with Sa_O2 < 90% (r = 0.265, P = 0.003), and oxygen desaturation index (r = 0.214, P = 0.019). After 6 months of treatment, there were no significant differences of changes in primary and secondary endpoints between the two treatment groups. Regression analysis showed that weight change over 6 months correlated with changes in both intrahepatic triglyceride and CAP (P < 0.001).Conclusions: Despite significant correlations between hepatic steatosis and markers of severity of OSA, CPAP alone did not improve hepatic steatosis and fibrosis. However, the additional role of weight reduction through lifestyle modification deserves further investigation.

Sleep-disordered breathing in patients with stroke-induced dysphagia

This study examined the nature and characteristics of sleep-disordered breathing, including obstructive sleep apnea and central sleep apnea, in patients with post-stroke dysphagia, to determine the demographic, anthropometric and clinical variables that were associated with sleep-disordered breathing. Thirty-nine patients diagnosed with acute stroke (28 males and 11 females with a mean age of 72.3 ± 10.0 years) underwent overnight polysomnography (within 3.9 ± 1.6 days after admission). Sleep-disordered breathing was described by the apnea-hypopnea index and its obstructive and central components by the obstructive apnea-hypopnea index and central apnea-hypopnea index, respectively. Severity of dysphagia was assessed using the Mann Assessment of Swallowing Ability score. Severity of stroke and functional dependence were assessed by the National Institute of Health Stroke Scale and the modified Barthel index, respectively. Most of the cohort (87%) had moderate-to-severe dysphagia (Mann Assessment of Swallowing Ability of 143.2 ± 19.9). Sleep-disordered breathing (apnea-hypopnea index ≥ 5 events/hr) was present in 38 participants (97%) with a mean apnea-hypopnea index of 37.5 ± 24.4 events/hr. Sleep-disordered breathing was predominantly obstructive in nature, with a mean obstructive apnea-hypopnea index and central apnea-hypopnea index of 19.6 ± 15.7 and 11.4 ± 17.6 events/hr, respectively. Multivariate linear regression analyses showed that the apnea-hypopnea index was associated with sex (p = .0001), body mass index (p = .029) and the modified Barthel index (p = .006); the obstructive apnea-hypopnea index was associated with the Mann Assessment of Swallowing Ability (p = .006), sex (p = .004) and body mass index (p = .015) and had a nonlinear relationship with the modified Barthel index (p = .019); and the central apnea-hypopnea index was associated with sex (p = .027) and the modified Barthel index (p = .019). The present study showed that dysphagia severity was associated with obstructive sleep apnea severity and this association was independent of sex, modified Barthel index and body mass index. However, stroke-induced dysphagia was not associated with central sleep apnea or overall sleep-disordered breathing.

SAS Care 1: sleep-disordered breathing in acute stroke an transient ischaemic attack - prevalence, evolution and association with functional outcome at 3 months, a prospective observational polysomnography study

Sleep-disordered breathing (SDB) is frequent in patients with acute stroke. Little is known, however about the evolution of SDB after stroke. Most of our knowledge stems from smaller cohort studies applying limited cardiopulmonary sleep recordings or from cross-sectional data collected in different populations.

This study aims to determine prevalence, type and intra-individual evolution of SDB based on full-night polysomnography (PSG) in acute stroke and 3 months thereafter. Furthermore, we aimed to identify predictors of SDB in the acute and chronic phase and to evaluate associations between SDB and functional outcome at 3 months (M3).

A total of 166 patients with acute cerebrovascular events were evaluated by full PSG at baseline and 105 again at M3. The baseline prevalence of SDB (apnoea–hypopnoea index (AHI)>5·h⁻¹) was 80.5% and 25.4% of the patients had severe SDB (AHI>30·h⁻¹). Obstructive sleep apnoea was more prevalent than central sleep apnoea (83.8% versus 13%). Mean±SD AHI was 21.4±17.6·h⁻¹and decreased significantly at M3 (18±16.4·h⁻¹; p=0.018). At M3, 91% of all patients with baseline SDB still had an AHI>5·h⁻¹ and in 68.1% the predominant type of SDB remained unchanged (78.9% in obstructive sleep apnoea and 44.4% in central sleep apnoea). The only predictors of SDB at baseline were higher age and body mass index and in the chronic phase additionally baseline AHI. Baseline AHI was associated with functional outcome (modified Rankin score >3) at M3.

The high prevalence of SDB in acute stroke, its persistence after 3 months, and the association with functional outcome supports the recommendation for a rapid SDB screening in stroke patients.

The high prevalence of SDB in acute stroke, its persistence after 3 months and its association with functional outcome support the recommendation for rapid SDB screening in stroke patientshttps://bit.ly/3bFWqV7

Systematic Review Investigating the Effects of Nonpharmacological Interventions During Sleep to Enhance Physical Rehabilitation Outcomes in People With Neurological Diagnoses

OBJECTIVE

Conduct a systematic review of nonpharmacological interventions applied during sleep to enhance physical rehabilitation outcomes of individuals with a neurological diagnosis.

DATA SOURCES

Three online databases were searched for original research.

STUDY SELECTION

Intervention studies were included that used outcome measures of impairment, activity, and/or participation.

DATA EXTRACTION

Two reviewers independently screened 2287 titles and abstracts, reviewed 101 full texts, extracted data, and assessed study quality and risk of bias for 9 included studies.

DATA SYNTHESIS

All included studies were randomized controlled trials involving continuous positive airway pressure (CPAP) with inpatient individuals with stroke and sleep apnea. Several studies also included long-term outpatient follow-ups. Results in terms of outcomes based on impairment, activity, and participation were mixed. However, several studies found that the use of CPAP following stroke and sleep apnea during early stroke recovery had benefits relative to no CPAP.

CONCLUSIONS

The only nonpharmacological intervention to be administered during sleep in a neurological population to improve physical rehabilitation outcomes was found to be CPAP. This review was complicated by the variety of outcome measures used, lack of physical rehabilitation description, and CPAP compliance. In general, participants who had acceptable to good CPAP compliance saw the largest improvements in physical rehabilitation outcomes. Several other promising methods of brain stimulation during sleep are discussed.

The Evolution of Sleep Apnea Six Months After Acute Ischemic Stroke and Thrombolysis

STUDY OBJECTIVES

Our goal was to investigate the evolution of prevalence, severity, and type of sleep apnea among patients who had an ischemic stroke, with or without treatment with thrombolysis after 6 months.

METHODS

We prospectively studied 204 patients who had an ischemic stroke (110 in the thrombolysis and 94 in the non-thrombolysis group). After follow-up, 177 patients were eligible for a final analysis (98 in the thrombolysis group and 79 in the non-thrombolysis group). An unattended sleep study with a three-channel portable device was performed both on admission and after the 6-month follow-up.

RESULTS

The patients receiving thrombolysis were younger than those in the non-thrombolysis group (mean 65.5 versus 69.6 years P = .039). Sleep apnea, defined as a respiratory event index (REI) ≥ 5 events/h, was diagnosed in 92.7% patients, 93.9% versus 91.1% (P = .488) in the thrombolysis and non-thrombolysis groups, respectively. The prevalence remained unchanged during follow-up. Mild sleep apnea progressed to moderate or severe sleep apnea in 69.2% of the patients. Globally, mean central apneas per hour increased by 2.2% (P = .002), whereas obstructive apneas declined by 1.7% (P = .014). The mean change of oxygen desaturation index was -6.1% (P < .001) in the thrombolysis group, -1.8% (P = .327) in the non-thrombolysis group, and 4.2% (P = .001) in the whole group. In the non-thrombolysis group, the risk for new sleep apnea incidence increased by 6.1-fold (P = .024) at follow-up when compared to the thrombolysis group.

CONCLUSIONS

Sleep apnea prevalence remained high in patients who had an ischemic stroke at 6 months post-stroke. The risk for developing sleep apnea after stroke was significantly lower among patients undergoing thrombolysis.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Title: Ischaemic Stroke and Sleep Apnea in Northern Part of Finland; Identifier: NCT01861275; URL: https://clinicaltrials.gov/ct2/show/NCT01861275.

Oropharyngeal Muscle Exercise Therapy Improves Signs and Symptoms of Post-stroke Moderate Obstructive Sleep Apnea Syndrome

The primary aim of the current study was to assess the effects of oropharingeal muscle exercises in obstruction severity on stroke patients with OSAS. The secondary aims were to evaluate the effects of the exercises on rehabilitation of neurological function, sleeping, and morphology change of upper airway. An open-label, single-blind, parallel-group, randomized, controlled trial was designed. Fifty post-stroke patients with moderate OSAS were randomly assigned into 2 groups (25 in each group). For the therapy group, oropharyngeal muscle exercise was performed during the daytime for 20 min, twice a day, for 6 weeks. The control group was subjected to sham therapy of deep breathing. Primary outcomes were the obstruction severity by polysomnography. Secondary outcomes included recovery of motor and neurocognitive function, personal activities of daily living assessment (ADL), sleep quality and sleepiness scale. It also included upper airway magnetic resonance imaging (MRI) measurements. Assessments were made at baseline and after 6-week exercise. Finally, 49 patients completed the study. The apnea–hypopnea index, snore index, arousal index, and minimum oxygen saturation improved after exercise (P < 0.05). Oropharyngeal muscle exercises improved subjective measurements of sleep quality (P = 0.017), daily sleepiness (P = 0.005), and performance (both P < 0.05) except for neurocognition (P = 0.741). The changes in obstruction improvement, sleep characteristics and performance scale were also associated with training time, as detected by Pearson's correlation analysis. The anatomic structural remodeling of the pharyngeal airway was measured using MRI, including the lager retropalatal distance (P = 0.018) and shorter length of soft palate (P = 0.044) compared with the baseline. Hence, oropharyngeal muscle exercise is a promising alternative treatment strategy for stroke patients with moderate OSAS.

Clinical Trial Registration:http://www.chictr.org.cn. Unique identifier: ChiCTR-IPR-16009970

Factors Associated with Cheyne-Stokes Respiration in Acute Ischemic Stroke

Background and Purpose

Cheyne-Stokes respiration (CSR) is frequently observed in patients with acute stroke. There have been conflicting opinions about the associations of CSR with the location and size of the lesion. We aimed to better define the clinical relevance and pathogenesis of CSR in acute stroke.

Methods

We investigated patients who had been admitted with acute ischemic stroke and received an overnight sleep apnea test. We collected data on demographics, risk factors, etiologic subtypes, initial vital signs, clinical course of the stroke, and parameters associated with respiratory events during the sleep apnea test. We performed a multivariate logistic regression analysis to determine the factors associated with CSR.

Results

Among 182 patients, 35 patients showed CSR in sleep apnea testing. Large-artery atherosclerosis or cardioembolism, bilateral hemispheric involvement, atrial fibrillation, low left-ventricle ejection fraction (LVEF), and left atrium (LA) enlargement were all associated with the presence of CSR. Multivariate analysis revealed that the previous modified Rankin Scale (mRS) score, bilateral hemispheric involvement, low LVEF, and LA enlargement were significantly associated with CSR. Subgroup analysis with large-artery atherosclerosis without cardiac disease revealed that the previous mRS score is the only independent factor associated with CSR.

Conclusions

CSR frequently occurs in strokes involving large arteries or due to cardioembolism, regardless of the location and severity of the stroke. Predisposing conditions such as preexisting neurologic disability, low LVEF, and LA enlargement are associated with CSR in acute stroke.

CPAP effects on atherosclerotic plaques in patients with sleep-disordered breathing and coronary artery disease: The ENTERPRISE trial

BACKGROUND

Sleep-disordered breathing (SDB) is a novel cardiovascular risk factor. To date, the effects of continuous positive airway pressure (CPAP) on coronary plaque atheroma in SDB patients with coronary artery disease (CAD) have remained unclear. The CPAP Effects on Atherosclerotic Plaques in Patients with Sleep-Disordered Breathing and Coronary Artery Disease (ENTERPRISE) trial was designed to evaluate the effects of CPAP treatment in addition to optimal medical treatment on coronary plaque regression in SDB patients.

METHODS

This study is planned as a prospective, randomized, open-label, single-center study. The presence of SDB is defined as a 3% oxygen desaturation index (ODI) of ≥15 events/h as measured by nocturnal pulse oximetry. A total of 100 eligible SDB patients undergoing intravascular ultrasound (IVUS)-guided percutaneous coronary intervention will be randomly assigned to either CPAP as add-on therapy or no CPAP for SDB (1:1 ratio for CPAP vs. no CPAP). The intervention will consist of 12 months of CPAP treatment. The primary endpoint will be percentage changes in plaque atheroma volume of the non-culprit lesion segment as measured by IVUS. A specialist sleep cardiology team will carefully monitor patients receiving CPAP treatment in order to quickly detect and resolve problems, and to motivate patients to continue treatment.

CONCLUSION

This study will provide novel information on the effects of SDB and its treatment with CPAP on coronary plaque stability with regard to secondary prevention of CAD.

Lack of Worsening of Sleep-Disordered Breathing After Recurrent Stroke in the BASIC Project

STUDY OBJECTIVES

To investigate the difference in sleep-disordered breathing (SDB) prevalence and severity after an index and recurrent stroke.

METHODS

In a sample of 40 subjects, home sleep apnea tests were performed a median of 10 days after an index ischemic stroke and 14 days after a recurrent ischemic stroke. A respiratory event index (REI) of ≥ 10 events/h (apneas plus hypopneas per hour of recording) was used to define clinically significant SDB. The relative difference in REI or relative SDB prevalence was used to compare the post-recurrent stroke measurement with that made after the index stroke, and was expressed as a rate ratio (RR) or prevalence ratio (PR). Adjusted regression models (negative binomial for REI and log binomial for SDB) included change in body mass index and time between the events.

RESULTS

The median time from index to recurrent stroke was 330.5 days (interquartile range [IQR]: 103.5, 766.5). The median REI was 17.5 (IQR: 9.0, 32.0) after the index stroke and 18.0 (IQR: 11.0, 25.5) after the recurrent stroke. The within-subject median difference was zero (IQR: -9, 7.5). The relative difference in REI was not significant in unadjusted or adjusted (RR: 0.97 [95% confidence interval: 0.76, 1.24]) models. The prevalence of SDB was not different after the recurrent stroke compared with the index stroke, in unadjusted or adjusted (PR: 1.10 [95% confidence interval: 0.91, 1.32]) models.

CONCLUSIONS

In this within-subject, longitudinal study, neither severity nor prevalence of SDB worsened after recurrent stroke.

Prevalence, Risk Factors, Outcomes, and Treatment of Obstructive Sleep Apnea in Patients with Cerebrovascular Disease: A Systematic Review

BACKGROUND

Obstructive sleep apnea (OSA) is known to increase the risk of cerebrovascular disease (CVD), and patients with CVD have high incidence of OSA. The study aimed to systematically evaluate the prevalence of OSA in patients with CVD.

MATERIALS AND METHODS

Medline, Embase, Science Citation Index, Wanfang, CNKI, and Wiley Online Library were thoroughly searched to identify relevant studies. Random-effects models were used to calculate the pooled rate estimates. Meta-regression and subgroup analysis were performed to explore potential sources of heterogeneity.

RESULTS

Thirty-seven studies with 3242 patients were analyzed. The prevalence of OSA (apnea hypopnea index [AHI] >10) ranged from 34.5% to 92.3%, the random-effects pooled prevalence was 61.9%. Furthermore, the prevalence of sleep disordered breathing (SDB) with AHI  greater than  5 was 70.4%, with AHI greater than 20 was 39.5%, and with AHI greater than 30 was 30.1%. Only 8.3% of the SDB was primarily central apnea. Seventeen studies reported risk factors for OSA, 6 of which used multivariate analyses to extract risk factors. In univariate meta-regression analysis, male had higher prevalence than female (P = .041). OSA was associated with increased length of hospitalization in 2 studies, and 1 long-term study reported severe sleep apnea was associated with poor functional outcome. Among the 5 studies on treatment, 3 indicated that early treatment with CPAP was effective; the remaining studies did not find benefit from CPAP treatment and reported the CPAP acceptance was poor.

CONCLUSIONS

There is high prevalence of OSA in patients with CVD (61.9%). Therefore, accurate diagnosis and treatment to OSA is very important so as to prevent CVD.

Cerebral vasoreactivity in response to a head-of-bed position change is altered in patients with moderate and severe obstructive sleep apnea

Motivation

Obstructive sleep apnea (OSA) can impair cerebral vasoreactivity and is associated with an increased risk of cerebrovascular disease. Unfortunately, an easy-to-use, non-invasive, portable monitor of cerebral vasoreactivity does not exist. Therefore, we have evaluated the use of near-infrared diffuse correlation spectroscopy to measure the microvascular cerebral blood flow (CBF) response to a mild head-of-bed position change as a biomarker for the evaluation of cerebral vasoreactivity alteration due to chronic OSA. Furthermore, we have monitored the effect of two years of continuous positive airway pressure (CPAP) treatment on the cerebral vasoreactivity.

Methodology

CBF was measured at different head-of-bed position changes (supine to 30° to supine) in sixty-eight patients with OSA grouped according to severity (forty moderate to severe, twenty-eight mild) and in fourteen control subjects without OSA. A subgroup (n = 13) with severe OSA was measured again after two years of CPAP treatment.

Results

All patients and controls showed a similar CBF response after changing position from supine to 30° (p = 0.819), with a median (confidence interval) change of -17.5 (-10.3, -22.9)%. However, when being tilted back to the supine position, while the control group (p = 0.091) and the mild patients with OSA (p = 0.227) recovered to the initial baseline, patients with moderate and severe OSA did not recover to the baseline (9.8 (0.8, 12.9)%, p < 0.001) suggesting altered cerebral vasoreactivity. This alteration was correlated with OSA severity defined by the apnea-hypopnea index, and with mean nocturnal arterial oxygen saturation. The CBF response was normalized after two years of CPAP treatment upon follow-up measurements.

Conclusion

In conclusion, microvascular CBF response to a head-of-bed challenge measured by diffuse correlation spectroscopy suggests that moderate and severe patients with OSA have altered cerebral vasoreactivity related to OSA severity. This may normalize after two years of CPAP treatment.

Post-Stroke Sleep-Disordered Breathing-Pathophysiology and Therapy Options

Sleep-disordered breathing (SDB), encompassing both obstructive and central sleep apnea, is prevalent in at least 50% of stroke patients. Small studies have shown vast improvements in post-stroke functional recovery outcomes after the treatment of SDB by continuous positive airway pressure. However, compliance to this therapy is very poor in this complex patient group. There are alternative therapy options for SDB that may be more amenable for use in at least some post-stroke patients, including mandibular advancement, supine avoidance, and oxygen therapy. There are few studies, however, that demonstrate efficacy and compliance with these alternative therapies currently. Furthermore, novel SDB-phenotyping approaches may help to provide important clinical information to direct therapy selection in individual patients. Prior to realizing individualized therapy, we need a better understanding of the pathophysiology of SDB in post-stroke patients, including the role of inherent phenotypic traits, as well as the contribution of stroke size and location. This review summarizes the available literature on SDB pathophysiology and treatment in post-stroke patients, identifies gaps in the literature, and sets out areas for further research.

Sleep Apnea in Patients Hospitalized With Acute Ischemic Stroke: Underrecognition and Associated Clinical Outcomes

STUDY OBJECTIVES

To evaluate clinical recognition of sleep apnea and related outcomes in patients hospitalized with acute ischemic stroke.

METHODS

A retrospective study of all patients hospitalized with acute ischemic stroke from April 2008 to December 2014. The primary predictor and outcome variables were sleep apnea and hospital mortality, respectively. Secondary outcomes were mechanical ventilation, hospital length of stay, and the survivor's functional level by the modified Rankin scale. A sensitivity multivariate regression analysis included the propensity score for cardiovascular comorbidities and sleep apnea.

RESULTS

Of 989 patients, 190 (19%) were considered to have sleep apnea. Only 42 patients (22%) received any treatment for sleep apnea during the hospital stay. Despite higher prevalence of cardiovascular comorbidities, the patients with sleep apnea had lower hospital mortality, 1% versus 5.6% in patients without sleep apnea (odds ratio [OR] 0.18; 95% confidence interval [CI], 0.03-0.58, P = .002). Only the National Institutes of Health Stroke Scale (NIHSS) and the Glasgow coma scale (GCS) were significant predictors of adjusted hospital mortality (OR 1.06, 95% CI 1.01-1.11, P = .01 and OR 0.61, 95% CI 0.51-0.69, P ≤ .001, respectively). A composite clinical propensity score for sleep apnea and cardiovascular comorbidities was significantly associated with decreased mortality, independent to either NIHSS (OR 0.11, 95% CI 0.017-0.71; P = .02) or GCS (OR 0.07, 95% CI 0.01-0.52; P = .01).

CONCLUSIONS

Prevalence of sleep apnea in our study was low, likely because of clinical underrecognition. Despite having more cardiovascular disease, the patients with acute stroke and sleep apnea had less severe neurological injury and lower unadjusted mortality than those without a history of sleep apnea.

Impact of obstructive sleep apnea on neurological recovery after ischemic stroke: A prospective study

OBJECTIVES

The presence of obstructive sleep apnea (OSA) has been found to adversely affect the neurological recovery after acute ischemic stroke (AIS) in previous observational studies. However, in most of these studies, diagnosis of OSA was based on oximetry data alone, raising concern in the accuracy of diagnosis as well as estimation of severity. Purpose of our study was to determine the prevalence and severity of OSA (based on polysomnography and American Association of Sleep Medicine [AASM] criteria) in patients with AIS and to compare the post-stroke neurological and functional outcome, in those with and without OSA.

MATERIALS AND METHODS

A prospective single-centre study was conducted over a period of eighteen months from January 2013. The demographic and clinical data were collected, and the etiology of stroke was classified according to TOAST classification. Subsequently, all selected patients (N=99) underwent premorbid sleep status assessment by Epworth Sleepiness Scale followed by polysomnography using Resmed ApneaLink polysomnograph. Data were analyzed to find out the prevalence and severity of OSA as well as its impact on neurological recovery as assessed by National Institutes of Health Stroke Scale (NIHSS) and modified Rankin scale (mRS) at different time points, starting from admission.

RESULTS

There was a high prevalence of OSA (~60%) with a quarter of them having severe OSA. The OSA group had a significantly higher mean NIHSS score at discharge (P=.002) and significantly higher mRS score (irrespective of severity of OSA) at all points of evaluation.

CONCLUSION

Ischemic stroke patients with OSA tend to have poor neurological and functional recovery, across all segments of stroke and OSA severity.

An Adaptive Treatment to Improve Positive Airway Pressure (PAP) Adherence in Patients With Obstructive Sleep Apnea: A Proof of Concept Trial

Despite the benefits of positive airway pressure (PAP) treatment, rates of adherence to treatment are suboptimal. This proof-of-concept study assessed the feasibility, acceptability, and clinical significance of an adaptive treatment strategy to improve adherence to PAP. All participants first completed a brief educational intervention. Those who did not show at least a 25% increase in PAP use were randomized to receive a second, more intensive intervention, either motivational enhancement treatment or self-management treatment. Results suggested adequate feasibility and acceptability. In addition, participants demonstrated significant increases in objective PAP use, improvements in sleep quality, and decreases in daytime sleepiness. This study represents a first step in the development and validation of an adaptive treatment strategy to improve PAP adherence.

A randomized controlled trial of an ambulatory approach versus the hospital-based approach in managing suspected obstructive sleep apnea syndrome

Comparisons of home-based versus hospital-based approach in managing patients with suspected obstructive sleep apnoea syndrome(OSAS). A prospective, controlled CPAP parallel study of new referrals with suspected OSAS randomized into group A) home-based or B) hospital-based approach. Following detection of AHI ≥ 15/hr by Embletta sleep study (group A) or polysomnography (group B), patients received CPAP for 3 months after an overnight autoCPAP titration at home or in hospital respectively. Modified intention-to-treat analysis of those with AHI ≥ 15/hr on CPAP (n = 86 vs 86) showed no difference in Epworth sleepiness score, the primary endpoint, but greater improvement in Sleep-Apnoea-Quality-of-Life-Index[difference 0.3,(95%CI 0.02, 0.6), p = 0.033] at 3 months in group A. The mean costs for the patients in group A and group B were HK$8479(989) and HK$22,248(2407) respectively. The mean difference between groups was HK$-13,769(USD 1770 equivalent) per patient with 95% CI. (−14324, −13213), p < 0.001. The waiting time of patients with AHI ≥ 15/hr who were started on CPAP treatment from the first clinic consultation to the diagnostic sleep test, autoCPAP titration, and CPAP treatment was 189.6, 148.8 and 145.0 days shorter in group A than group B respectively. Home-based approach is non-inferior to hospital-based approach in managing patients with suspected OSAS, with shorter waiting time, and substantial cost savings.

Rehabilitation of Cardiovascular Disorders and Sleep Apnea

Obstructive sleep apnea (OSA) is present in more than 50% of patients referred to cardiac rehabilitation units. However, it has been under-recognized in patients after stroke and heart failure. Those with concurrent OSA have a worse clinical course. Early treatment of coexisting OSA with continuous positive airway pressure (CPAP) results in improved rehabilitation outcomes and quality of life. Possible mechanisms by which CPAP may improve recovery include decreased blood pressure fluctuations associated with apneas, and improved left ventricular function, cerebral blood flow, and oxygenation. Early screening and treatment of OSA should be integral components of patients entering cardiac rehabilitation units.

Sleep and Cognitive Abnormalities in Acute Minor Thalamic Infarction

In order to characterize sleep and the cognitive patterns in patients with acute minor thalamic infarction (AMTI), we enrolled 27 patients with AMTI and 12 matched healthy individuals. Questionnaires about sleep and cognition as well as polysomnography (PSG) were performed on days 14 and 90 post-stroke. Compared to healthy controls, in patients with AMTI, hyposomnia was more prevalent; sleep architecture was disrupted as indicated by decreased sleep efficiency, increased sleep latency, and decreased non-rapid eye movement sleep stages 2 and 3; more sleep-related breathing disorders occurred; and cognitive functions were worse, especially memory. While sleep apnea and long-delay memory recovered to a large extent in the patients, other sleep and cognitive function deficit often persisted. Patients with AMTI are at an increased risk for hyposomnia, sleep structure disturbance, sleep apnea, and memory deficits. Although these abnormalities improved over time, the slow and incomplete improvement suggest that early management should be considered in these patients.

Apnea-hypopnea index, nocturnal arousals, oxygen desaturation and structural brain changes: A population-based study

Sleep apnea has been related to brain changes such as atrophy. However, which component of sleep apnea, the apnea-hypopnea index (AHI), nocturnal oxygen desaturation or arousals, can explain this association is unclear. In this large population-based study (n=681, mean age 62.1 years), we investigated the associations of AHI, nocturnal oxygen desaturation and arousals with global and regional gray matter and white matter volumes and with white matter lesion volumes. All participants underwent one night of polysomnography and MRI scanning of their brain. Gray matter, white matter and white matter lesion volumes adjusted for intracranial volume were studied as markers of brain atrophy. Nocturnal oxygen desaturation was related to whole brain white matter atrophy independent of covariates (multivariable adjusted B=−8.3, 95% CI=−16.7; −0.02). This association was most prominently reflected in the association between more oxygen desaturation and a smaller white matter parietal volume (B=−3.95 ml, 95% CI=−6.02; −1.88). Furthermore, oxygen desaturation was related to a smaller hippocampus (B=−0.22 ml, 95% CI=−0.42; −0.01). Although a higher AHI was related to smaller parietal gray (B=−0.05, 95% CI=−0.09; −0.004) and white matter (B=−0.06, 95% CI=−0.12; −0.10) volumes, these associations disappeared when adding oxygen desaturation to the model. We did not find a relation between arousals and gray and white matter brain atrophy and white matter lesion volumes. This suggests that oxygen desaturation mainly explains the association between sleep apnea and brain damage.

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Nocturnal oxygen desaturation is associated with a smaller white matter volume.

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A higher AHI is related to smaller parietal gray and white matter volumes.

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These associations disappear when adding oxygen desaturation to the model.

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Oxygen desaturation mainly explains the association between apnea and brain damage.

A Randomized Controlled Study to Examine the Effect of a Lifestyle Modification Program in OSA

BACKGROUND

Obesity is an important risk factor for OSA. This study aimed to assess the effect of weight reduction through a lifestyle modification program (LMP) on patients with moderate to severe OSA.

METHODS

This was a parallel group, randomized controlled trial. Altogether, 104 patients with moderate to severe OSA diagnosed on portable home sleep monitoring were randomized to receive a dietician-led LMP or usual care for 12 months. The primary outcome was reduction of apnea-hypopnea index (AHI) at 12 months as assessed by portable home sleep monitoring.

RESULTS

In the intention-to-treat analysis (ITT), LMP (n = 61) was more effective in reducing AHI from baseline (16.9% fewer events in the LMP group vs 0.6% more events in the control group, P = .011). LMP was more effective in reducing BMI (-1.8 kg/m2, 6.0% of the initial BMI; -0.6 kg/m2, 2.0% of the initial BMI in control group; P < .001). The reduction in daytime sleepiness as assessed by Epworth Sleepiness Scale was not significant in ITT but was more in the LMP group (-3.5 in the LMP group vs -1.1 in the control group, P = .004) by treatment per protocol analysis. There was modest improvement in mental health in the Short Form Health Survey. Eating behavior was improved with increased intake of protein and fiber. These changes were observed 4 months after the initial intensive diet counseling and persisted at 12 months.

CONCLUSIONS

LMP was effective in reducing the severity of OSA and daytime sleepiness. The beneficial effect was sustained in 12 months.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT01384760; URL: www.clinicaltrials.gov.

Associations between Cardioembolic Stroke and Obstructive Sleep Apnea

STUDY OBJECTIVES

To assess etiology of ischemic stroke in patients with obstructive sleep apnea (OSA) compared with controls. This information may aid in determining how OSA increases stroke risk and facilitate recurrent stroke prevention in patients with OSA.

DESIGN

Retrospective, case-control study.

SETTING

Academic tertiary referral center.

PATIENTS

Consecutive patients who underwent polysomnography and had an ischemic stroke within 1 year were identified. Stroke subtype was determined using two validated algorithms. Polysomnographic results were used to separate patients into OSA cases and controls. Information regarding cardiovascular risks, neuroimaging, and echocardiographic data were collected.

INTERVENTIONS

N/A.

MEASUREMENTS AND RESULTS

In 53 subjects, cardioembolic (CE) strokes were more common among OSA cases than controls (72% versus 33%, P = 0.01). The majority of CE strokes occurred in those with moderate to severe OSA. Atrial fibrillation (AF) was more frequent in OSA cases (59% versus 24%, P = 0.01). The association between OSA and CE stroke remained significant after controlling for AF (P = 0.03, odds ratio 4.5).

CONCLUSIONS

There appears to be a strong association between obstructive sleep apnea (OSA) and cardioembolic (CE) stroke. In patients with OSA presenting with cryptogenic stroke, high clinical suspicion for CE is warranted. This may lead to consideration of diagnostic studies to identify CE risk factors such as paroxysmal atrial fibrillation (AF). CE strokes are more common in patients with OSA even after adjusting for AF. This finding may reflect a high rate of occult paroxysmal AF in this population; alternatively, OSA may lead to CE strokes through mechanisms independent of AF.

Infarct location and sleep apnea: evaluating the potential association in acute ischemic stroke

BACKGROUND

The literature about the relationship between obstructive sleep apnea (OSA) and stroke location is conflicting with some studies finding an association and others demonstrating no relationship. Among acute ischemic stroke patients, we sought to examine the relationship between stroke location and the prevalence of OSA; OSA severity based on apnea-hypopnea index (AHI), arousal frequency, and measure of hypoxia; and number of central and obstructive respiratory events.

METHODS

Data were obtained from patients who participated in a randomized controlled trial (NCT01446913) that evaluated the effectiveness of a strategy of diagnosing and treating OSA among patients with acute ischemic stroke and transient ischemic attack. Stroke location was classified by brain imaging reports into subdivisions of lobes, subcortical areas, brainstem, cerebellum, and vascular territory. The association between acute stroke location and polysomnographic findings was evaluated using logistic regression for OSA presence and negative binomial regression for AHI.

RESULTS

Among 73 patients with complete polysomnography and stroke location data, 58 (79%) had OSA. In unadjusted models, no stroke location variable was associated with the prevalence or severity of OSA. Similarly, in multivariable modeling, groupings of stroke location were also not associated with OSA presence.

CONCLUSIONS

These results indicate that OSA is present in the majority of stroke patients and imply that stroke location cannot be used to identify a group with higher risk of OSA. The results also suggest that OSA likely predated the stroke. Given this high overall prevalence, strong consideration should be given to obtaining polysomnography for all ischemic stroke patients.

Adaptive servo-ventilation as treatment of persistent central sleep apnea in post-acute ischemic stroke patients

BACKGROUND

Adaptive servo-ventilation (ASV) is a well-established treatment of central sleep apnea (CSA) related to congestive heart failure (CHF). Few studies have evaluated the effectiveness and adherence in patients with CSA of other etiologies, and even less is known about treatment of CSA in patients of post ischemic stroke.

METHODS

A single-centre retrospective analysis of ASV treatment for CSA in post-acute ischemic stroke patients without concomitant CHF was performed. Demographics, clinical data, sleep studies, ventilator settings, and adherence data were evaluated.

RESULTS

Out of 154 patients on ASV, 15 patients had CSA related to ischemic stroke and were started on ASV a median of 11 months after the acute cerebrovascular event. Thirteen out of the 15 patients were initially treated with continuous positive airway pressure (11/15) and bilevel positive airway pressure (2/15) therapy with unsatisfactory control of CSA. ASV significantly improved AHI (46.7 ± 24.3 vs 8.5 ± 12/h, P = 0.001) and reduced ESS (8.7 ± 5.7 vs 5.6 ± 2.5, P = 0.08) with a mean nightly use of ASV of 5.4 ± 2.4 h at 3 months after the initiation of treatment. Results were maintained at 6 months.

CONCLUSION

ASV was well tolerated and clinically effective in this group of patients with persistent CSA after ischemic stroke.

Guidelines for the prevention of stroke in patients with stroke and transient ischemic attack: a guideline for healthcare professionals from the American Heart Association/American Stroke Association

The aim of this updated guideline is to provide comprehensive and timely evidence-based recommendations on the prevention of future stroke among survivors of ischemic stroke or transient ischemic attack. The guideline is addressed to all clinicians who manage secondary prevention for these patients. Evidence-based recommendations are provided for control of risk factors, intervention for vascular obstruction, antithrombotic therapy for cardioembolism, and antiplatelet therapy for noncardioembolic stroke. Recommendations are also provided for the prevention of recurrent stroke in a variety of specific circumstances, including aortic arch atherosclerosis, arterial dissection, patent foramen ovale, hyperhomocysteinemia, hypercoagulable states, antiphospholipid antibody syndrome, sickle cell disease, cerebral venous sinus thrombosis, and pregnancy. Special sections address use of antithrombotic and anticoagulation therapy after an intracranial hemorrhage and implementation of guidelines.

Brainstem infarcts predict REM sleep behavior disorder in acute ischemic stroke

Background

Rapid eye movement (REM) sleep behavior disorder (RBD) is a sleep disturbance in which patients enact their dreams while in REM sleep. The behavior is typically violent in association with violent dream content, so serious harm can be done to the patient or the bed partner. The prevalence of RBD is well-known in Parkinson’s disease, Lewy body dementia, and multiple systems atrophy. However, its prevalence and causes in stroke remained unclear. The aim of this study was to determine factors influencing the appearance of RBD in a prospective cohort of patients with acute ischemic stroke.

Methods

A total of 2,024 patients with first-ever or recurrent acute ischemic stroke were admitted to the Acute Stroke Unit at the Prince of Wales Hospital between January 2010 and November 2011; 775 of them received an MRI scan. Within 2 days of admission, a research nurse collected demographic and clinical data and assessed the severity of each stroke using the National Institute of Health Stroke Scale (NIHSS). One hundred and nineteen of the 775 patients meeting study entry criteria formed the study sample. All eligible participants were invited to attend a research clinic 3 months after the onset of the index stroke. In the attendance, a research assistant administered the MMSE and the 13-item RBD questionnaire (RBDQ).

Results

Among 119 stroke patients, 10.9% were exhibited RBD, defined as an REM sleep behavior disorder questionnaire score of 19 or above. The proportion of patients with acute brainstem infarct was significantly higher in RBD patients than those without RBD. Compared with patients without RBD, RBD patients were more likely to have brainstem infarcts and had smaller infarct volumes. In a multivariate analysis, in which stroke location and infarct volume were inserted, brainstem infarcts were an independent predictor of RBD (odds ratio = 3.686; P = 0.032).

Conclusions

The results support the notion of a predominant role of brainstem injury in the development of RBD and suggest that patients with brainstem infarcts RBD should be evaluated by a clinical neurologist.

The effect of obstructive sleep apnea and treatment with continuous positive airway pressure on stroke rehabilitation: rationale, design and methods of the TOROS study

Background

Obstructive sleep apnea is a common sleep disorder in stroke patients. Obstructive sleep apnea is associated with stroke severity and poor functional outcome. Continuous positive airway pressure seems to improve functional recovery in stroke rehabilitation. To date, the effect of continuous positive airway pressure on cognitive functioning in stroke patients is not well established. The current study will investigate the effectiveness of continuous positive airway pressure on both cognitive and functional outcomes in stroke patients with obstructive sleep apnea.

Methods/Design

A randomized controlled trial will be conducted on the neurorehabilitation unit of Heliomare, a rehabilitation center in the Netherlands. Seventy stroke patients with obstructive sleep apnea will be randomly allocated to an intervention or control group (n = 2×35). The intervention will consist of four weeks of continuous positive airway pressure treatment. Patients allocated to the control group will receive four weeks of treatment as usual. Outcomes will be assessed at baseline, immediately after the intervention and at two-month follow-up.

In a supplementary study, these 70 patients with obstructive sleep apnea will be compared to 70 stroke patients without obstructive sleep apnea with respect to cognitive and functional status at rehabilitation admission. Additionally, the societal participation of both groups will be assessed at six months and one year after inclusion.

Discussion

This study will provide novel information on the effects of obstructive sleep apnea and its treatment with continuous positive airway pressure on rehabilitation outcomes after stroke.

Trial registration

Trial registration number: Dutch Trial Register NTR3412

Epidemiology of Obstructive Sleep Apnea: a Population-based Perspective

This review summarizes the recent literature on the epidemiology of adult obstructive sleep apnea (OSA) from various population-based studies. Despite methodologic differences, comparisons have yielded similar prevalence rates of the OSA syndrome in various geographic regions and amongst a number of ethnic groups. Risk factors for OSA including obesity, aging, gender, menopause, and ethnicity are analyzed. We also provide discussion on adverse medical conditions associated with OSA including hypertension, stroke, congestive heart failure, coronary artery disease, cardiovascular mortality, insulin resistance, and neurocognitive dysfunction. Finally with the progression of the global obesity epidemic, we focus on the economic health care burden of OSA and the importance of recognizing the largely undiagnosed OSA population with emphasis on strategies to improve access to diagnostic resources.

Interaction between Sleep-Disordered Breathing and Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Sleep-disordered breathing (SDB) is suggested to be strongly associated with ischemic strokes. Risk factors, stroke subtypes, stroke lesion distribution, and the outcome of SDB in stroke patients remain unclear in Korea.

METHODS

We prospectively studied 293 patients (159 men, 134 women; age 68.4±10.5) with acute ischemic stroke. Cardiovascular risk factors, stroke severity, sleep-related stroke onset, distribution of stroke lesions, and 3-month score on the modified Rankin Scale (mRS) were assessed. Stroke severity was assessed by the US National Institutes of Health Stroke Scale (NIHSS) and the mRS. The apnea-hypopnea index (AHI) was determined 6.3±2.2 days after stroke onset with the Apnea Link portable sleep apnea monitoring device.

RESULTS

The prevalence of SDB (defined as an AHI of ≥10) was 63.1% (111 men, 74 women). Those in the SDB group were older, had higher NIHSS and mRS scores, greater bulbar weakness, and a higher incidence of sleep-associated stroke onset. Among risk-factor profiles, alcohol consumption and atrial fibrillation were significantly related to SDB. The stroke outcome was worse in patients with SDB than in those without SDB. The lesion location and specific stroke syndrome were not correlated with SDB.

CONCLUSIONS

SDB is very common in acute cerebral infarction. Different risk-factor profiles and sleep-related stroke onsets suggest SDB as a cause of ischemic stroke. The higher NIHSS score and greater bulbar involvement in the SDB group seem to show the influence of ischemic stroke on the increased SDB prevalence.

Obstructive sleep apnea and stroke

Obstructive sleep apnea (OSA) is a common disorder that has been associated with many cardiovascular disease processes, including hypertension and arrhythmias. OSA has also been identified as an independent risk factor for stroke and all-cause mortality. OSA is highly prevalent in patients with transient ischemic attacks and stroke. Routinely screening patients with transient ischemic attacks or stroke for sleep apnea is becoming more common. In stroke patients with OSA, treatment with continuous positive airway pressure may prevent subsequent cardiovascular events and improve neurologic outcomes. This review explores the pathophysiology of the association between OSA and stroke, and the clinical implications of identification and treatment of OSA in patients with stroke.

Sleep-Disordered Breathing in Acute Ischemic Stroke and Transient Ischemic Attack: Effects on Short- and Long-Term Outcome and Efficacy of Treatment with Continuous Positive Airways Pressure – Rationale and Design of the SAS Care Study

Objectives

Sleep-disordered breathing represents a risk factor for cardiovascular morbidity and mortality and negatively affects short-term and long-term outcome after an ischemic stroke or transient ischemic attack. The effect of continuous positive airways pressure in patients with sleep-disordered breathing and acute cerebrovascular event is poorly known. The SAS CARE 1 study assesses the effects of sleep-disordered breathing on clinical evolution, vascular functions, and markers within the first three-months after an acute cerebrovascular event. The SAS CARE 2 assesses the effect of continuous positive airways pressure on clinical evolution, cardiovascular events, and mortality as well as vascular functions and markers at 12 and 24 months after acute cerebrovascular event.

Methods

SAS CARE 1 is an open, observational multicenter study in patients with acute cerebrovascular event acutely admitted in a stroke unit: a sample of 200 acute cerebrovascular event patients will be included. Vascular functions and markers (blood pressure, heart rate variability, endothelial function by peripheral arterial tonometry and specific humoral factors) will be assessed in the acute phase and at three-months follow-up. SAS CARE 2 will include a sample of patients with acute cerebrovascular event in the previous 60–90 days. After baseline assessments, the patients will be classified according to their apnea hypopnea index in four arms: non-sleep-disordered breathing patients (apnea hypopnea index <10), patients with central sleep-disordered breathing, sleepy patients with obstructive apnea hypopnea index ≥20, which will receive continuous positive airways pressure treatment, nonsleepy patients with obstructive sleep-disordered breathing (apnea hypopnea index ≥20), which will be randomized to receive continuous positive airways pressure treatment or not.

Conclusions

The SAS CARE study will improve our understanding of the clinical sleep-disordered breathing in patients with acute cerebrovascular event and the feasibility/efficacy of continuous positive airways pressure treatment in selected patients with acute cerebrovascular event and sleep-disordered breathing.