Efficacy of continuous positive airway pressure treatment on 5-year survival in patients with ischaemic stroke and obstructive sleep apnea: a randomized controlled trial

Effect of CPAP Treatment of Sleep Apnea on Clinical Prognosis After Ischemic Stroke: An Observational Study

STUDY OBJECTIVES

To evaluate continuous positive airway pressure (CPAP) treatment in patients with moderate to severe sleep-disordered breathing (SDB) after an ischemic stroke.

METHODS

We identified patients included in the Acute Stroke Registry and Analysis of Lausanne (ASTRAL) who underwent polysomnography after an ischemic stroke. We compared patients without significant SDB (apnea-hypopnea index [AHI] < 15 events/h: SDB-), with AHI ≥ 15 events/h who refused CPAP or with poor CPAP adherence (SDB+ CPAP-), and patients with SDB effectively treated by CPAP (SDB+ CPAP+).

RESULTS

We analyzed data from 101 patients (age 68.5 ± 11.1 years, 84.1% men). In multivariate analysis the SDB+ CPAP+ group was associated with a significant reduction of stroke recurrence and mortality (odds ratio 0.13, 95% confidence interval 0.00-0.86, P = .031), whereas atrial fibrillation was independently associated with a higher risk (odds ratio 4.32, 95% confidence interval 1.51-12.33, P = .006). Event-free survival analysis (stroke recurrence and death) after 2-year follow-up showed that those in the SDB+ CPAP+ group had significantly higher cardiovascular survival, and Cox proportion hazard model identified CPAP treatment as significantly associated with survival time (P = .025). The AHI and the National Institutes of Health Stroke Scale subacute score were independently associated with CPAP adherence among patients with SDB.

CONCLUSIONS

This observational study shows that CPAP treatment in stroke patients with moderate to severe SDB is associated with lower rates of stroke recurrence and death.

Sleep Disordered Breathing and Cardiovascular Diseases

Sleep disordered breathing (SDB), which causes sleep deprivation, intermittent hypoxia, and negative intrathoracic pressure swings, can be accompanied by other harmful pathophysiologies relating to cardiovascular diseases (CVD), including sudden death, atrial fibrillation, stroke, and coronary artery disease leading to heart failure. Continuous positive airway pressure (CPAP) therapy for SDB has been reported to provide favorable effects such as lowered systemic blood pressure and improved endothelial function. However, in recent randomized controlled trials, CPAP has failed to demonstrate its beneficial prognostic impact on the primary or secondary setting of CVD. In this review article, we describe the characteristics of SDB complicated with CVD, the prognostic impacts of SDB in CVD, and the beneficial effects of CPAP on CVD.

Treatment of Adult Obstructive Sleep Apnea With Positive Airway Pressure: An American Academy of Sleep Medicine Systematic Review, Meta-Analysis, and GRADE Assessment

INTRODUCTION

The purpose of this systematic review is to provide supporting evidence for the clinical practice guideline for the treatment of obstructive sleep apnea (OSA) in adults using positive airway pressure (PAP).

METHODS

The American Academy of Sleep Medicine commissioned a task force of experts in sleep medicine. A systematic review was conducted to identify studies that compared the use of PAP with no treatment as well as studies that compared different PAP modalities. Meta-analyses were performed to determine the clinical significance of using PAP in several modalities (ie, continuous PAP, auto-adjusting PAP, and bilevel PAP), to treat OSA in adults. In addition, meta-analyses were performed to determine the clinical significance of using an in-laboratory versus ambulatory strategy for the initiation of PAP, educational and behavioral interventions, telemonitoring, humidification, different mask interfaces, and flexible or modified pressure profile PAP in conjunction with PAP to treat OSA in adults. Finally, the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) process was used to assess the evidence for making recommendations.

RESULTS

The literature search resulted in 336 studies that met inclusion criteria; 184 studies provided data suitable for meta-analyses. The data demonstrated that PAP compared to no treatment results in a clinically significant reduction in disease severity, sleepiness, blood pressure, and motor vehicle accidents, and improvement in sleep-related quality of life in adults with OSA. In addition, the initiation of PAP in the home demonstrated equivalent effects on patient outcomes when compared to an in-laboratory titration approach. The data also demonstrated that the use of auto-adjusting or bilevel PAP did not result in clinically significant differences in patient outcomes compared with standard continuous PAP. Furthermore, data demonstrated a clinically significant improvement in PAP adherence with the use of educational, behavioral, troubleshooting, and telemonitoring interventions. Systematic reviews for specific PAP delivery method were also performed and suggested that nasal interfaces compared to oronasal interfaces have improved adherence and slightly greater reductions in OSA severity, heated humidification compared to no humidification reduces some continuous PAP-related side effects, and pressure profile PAP did not result in clinically significant differences in patient outcomes compared with standard continuous PAP.

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.

Oximetry as an Accurate Tool for Identifying Moderate to Severe Sleep Apnea in Patients With Acute Stroke

STUDY OBJECTIVES

Sleep-disordered breathing (SDB) is highly prevalent in patients with acute stroke. SDB is often underdiagnosed and associated with neurological deterioration and stroke recurrence. Polysomnography or home sleep apnea testing (HSAT) is typically used as the diagnostic modality; however, it may not be feasible to use regularly in patients with acute stroke. We investigated the predictive performance of pulse oximetry, a simpler alternative, to identify SDB.

METHODS

The records of 254 patients, who were admitted to Boston Medical Center for acute stroke and underwent HSAT, were retrospectively reviewed. Oxygen desaturation index (ODI) from pulse oximetry channel were compared to respiratory event index (REI) obtained from HSAT devices. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of ODI were calculated, and different ODI cutoff values to predict SDB were proposed.

RESULTS

ODI had a strong correlation (r = .902) and agreement with REI. ODI was accurate in predicting SDB at different REI thresholds (REI ≥ 5, REI ≥ 15, and REI ≥ 30 events/h) with the area under the curve (AUC) of .965, .974, and .951, respectively. An ODI ≥ 5 events/h rules in the presence of SDB (specificity 91.7%, PPV 96.3%). An ODI ≥ 15 events/h rules in moderate to severe SDB (specificity 96.4%, PPV 95%) and an ODI < 5 events/h rules out moderate to severe SDB (sensitivity 100%, NPV 100%).

CONCLUSIONS

Nocturnal pulse oximetry has a high diagnostic accuracy in predicting moderate to severe SDB in patients with acute stroke. Oximetry can be a simple modality to rapidly recognize patients with more severe SDB and facilitate the referral to the confirmation sleep study.

Sleep-disordered breathing and stroke: chicken or egg?

The bidirectional interaction between sleep-disordered breathing (SDB) and stroke has been the subject of many studies. On the one hand, different forms of SDB, and especially obstructive sleep apnea, increase the risk of stroke either directly or indirectly by influencing other known cardiovascular risk factors such as arterial hypertension and arrhythmias. On the other hand, stroke itself can cause either de novo appearance of SDB, aggravate a pre-existing SDB, or trigger a transition from one type of pathological SDB pattern into another. In this review, we discuss some aspects of this "chicken or egg" relationship.

Continuous positive airway pressure for adults with obstructive sleep apnea and cardiovascular disease: a meta-analysis of randomized trials

BACKGROUND

It remains uncertain whether continuous positive airway pressure (CPAP) therapy would significantly impact hard clinical outcomes in patients with obstructive sleep apnea (OSA). This meta-analysis aimed to assess the effects of CPAP in survival and secondary prevention of major cardiovascular events in patients with OSA and cardiovascular disease (CVD).

METHODS

PubMed, Cochrane CENTRAL, LILACS, and SciElo databases (up to January 2018) were searched for randomized trials that compared CPAP with no active treatment in adults with OSA and CVD. The primary outcomes were all-cause death, cardiovascular death, acute myocardial infarction, stroke, and any major cardiovascular event. We used risk ratios (RR) and 95% confidence interval (CI) as the effect measures for dichotomous data, and weighted mean difference (WMD) and 95% CI for continuous variables. We used the random-effects method for meta-analysis.

RESULTS

Nine trials involving 3314 patients contributed data for meta-analysis of at least one outcome. The duration (median) of CPAP treatment varied from one month to 56.9 months. The pooled RR (95% CI) was 0.86 (0.60-1.23, I² = 0.0%) for all-cause death, 0.58 (0.19-1.74, I² = 47%) for cardiovascular death, 1.11 (0.76-1.62, I² = 0.0%) for myocardial infarction, 0.77 (0.46-1.28, I² = 16%) for stroke, and 0.93 (0.70-1.24, I² = 49%) for any major cardiovascular event. The quality of evidence for these outcomes was low.

CONCLUSIONS

Low-quality evidence suggests that CPAP therapy does not significantly improve survival or prevent major cardiovascular events in adults with OSA and cardiovascular disease.

A consensus opinion amongst stakeholders as to benefits of obstructive sleep apnoea treatment for cardiovascular health

BACKGROUND AND OBJECTIVE

Obstructive sleep apnoea (OSA) is a prevalent sleep disorder associated with increased cardiovascular morbidity and mortality. Whether treatment of OSA improves cardiovascular risk remains controversial. Our aim was to determine a consensus opinion of key sleep medicine stakeholder groups as to the cardiovascular benefits of treating moderate-severe OSA.

METHODS

A multidisciplinary panel was assembled from representatives from the Australasian Sleep Association, Sleep Health Foundation, Australasian Sleep Technologists Association, the Sleep Health Foundation Business Council and the Sleep Disorders Australia patient support group. Three statements reflecting areas of controversy related to cardiovascular benefits of OSA treatment were created. A modified RAND/UCLA appropriateness methodology was applied determining the panel's level of consensus and agreement with each statement.

RESULTS

Voting results indicated the panel: (1) remained unsure whether moderate-severe OSA treatment improves rates of cardiovascular events/death, (2) agreed that moderate-severe OSA treatment improves blood pressure in patients with hypertension and (3) mostly agreed that moderate-severe OSA treatment improves left ventricular function in patients with heart failure. Consensus of opinion was achieved for statements (1) and (2), but was narrowly missed for statement (3).

CONCLUSION

The panel believed that findings from large-scale randomized trials indicate that treatment of moderate-severe OSA has not been established to improve cardiovascular event or morbidity/mortality rates. Strong evidence supports the ability of treatment to reduce blood pressure. Whilst many panel members believed that treatment improves left ventricular function, some were uncertain of the clinical significance of this secondary endpoint measure derived from lesser quality evidence.

Role of Positive Airway Pressure Therapy for Obstructive Sleep Apnea in Patients With Stroke: A Randomized Controlled Trial

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) is an independent risk factor for stroke. The objective of this study was to assess the effect of continuous positive airway pressure (CPAP) treatment on prevention of new vascular events among patients with stroke and OSA.

METHODS

Consecutive conscious patients presenting with first imaging-confirmed arterial stroke were included, 6 weeks or more after ictus. All patients underwent clinical and polysomnography (PSG) testing. Patients with an apnea-hypopnea index (AHI) of > 15 events/h were randomized to posttitration nightly CPAP treatment and non-CPAP (received best medical treatment) groups. On follow-up at 3, 6, and 12 months from randomization, evaluation was carried out for any new vascular events as the primary outcome measure, and for clinical stroke outcomes (using the Barthel Index and modified Rankin scale) and neuropsychological parameters as the secondary outcome measures.

RESULTS

Among the 679 patients with stroke who were screened, 116 reported for PSG, 83 had AHI > 15 events/h, and 70 (34 in CPAP and 36 in non-CPAP) were randomized. Thirteen patients could not be randomized because of a lack of CPAP devices. Four patients crossed over from the CPAP to the non-CPAP group. Age (mean age 53.41 ± 9.85 in CPAP versus 52.69 ± 13.23 years in non-CPAP, P = .81) and sex distribution (24 males in CPAP versus 33 males in non-CPAP, P = .79) were similar in both groups. At 12-month follow-up, there was 1 vascular event (3.33%) in the CPAP group and 6 events (15%) in the non-CPAP group (P = .23). Modified Rankin scale score improvement by ≥ 1 at 12-month follow-up was found in significantly more patients in the CPAP group than in the non-CPAP group (53% versus 27%).

CONCLUSIONS

These findings suggest significantly better stroke outcomes and statistically nonsignificant favorable outcomes in terms of recurrence of vascular events for patients with stroke and OSA who use CPAP treatment.

CLINICAL TRIAL REGISTRATION

Registry: Clinical Trials Registry - India, CTRI Registration No: CTRI/2016/07.007104, Title: Sleep Disordered Breathing in stroke patients: Effect of treatment trial, URL: http://ctri.nic.in/Clinicaltrials/showallp.php?mid1=8682&EncHid=&userName=sleep%20disordered%20breathing.

CPAP as treatment of sleep apnea after stroke: A meta-analysis of randomized trials

OBJECTIVE

To perform a systematic review and meta-analysis of randomized controlled trials (RCTs) examining the effectiveness of continuous positive airway pressure (CPAP) in stroke patients with sleep disordered breathing (SDB).

METHODS

In a systematic literature search of electronic databases (MEDLINE, Embase, and the Cochrane Library) from 1980 to November 2016, we identified RCTs that assessed CPAP compared to standard care or sham CPAP in adult patients with stroke or TIA with SDB. Mean CPAP use, odds ratios (ORs), and standardized mean differences (SMDs) were calculated. The prespecified outcomes were adherence to CPAP, neurologic improvement, adverse events, new vascular events, and death.

RESULTS

Ten RCTs (564 participants) with CPAP as intervention were included. Two studies compared CPAP with sham CPAP; 8 compared CPAP with usual care. Mean CPAP use across the trials was 4.53 hours per night (95% confidence interval [CI] 3.97-5.08). The OR of dropping out with CPAP was 1.83 (95% CI 1.05-3.21, p = 0.033). The combined analysis of the neurofunctional scales (NIH Stroke Scale and Canadian Neurological Scale) showed an overall neurofunctional improvement with CPAP (SMD 0.5406, 95% CI 0.0263-1.0548) but with a considerable heterogeneity (I² = 78.9%, p = 0.0394) across the studies. Long-term survival was improved with CPAP in 1 trial.

CONCLUSION

CPAP use after stroke is acceptable once the treatment is tolerated. The data indicate that CPAP might be beneficial for neurologic recovery, which justifies larger RCTs.

Sleep Apnea: Types, Mechanisms, and Clinical Cardiovascular Consequences

Sleep apnea is highly prevalent in patients with cardiovascular disease. These disordered breathing events are associated with a profile of perturbations that include intermittent hypoxia, oxidative stress, sympathetic activation, and endothelial dysfunction, all of which are critical mediators of cardiovascular disease. Evidence supports a causal association of sleep apnea with the incidence and morbidity of hypertension, coronary heart disease, arrhythmia, heart failure, and stroke. Several discoveries in the pathogenesis, along with developments in the treatment of sleep apnea, have accumulated in recent years. In this review, we discuss the mechanisms of sleep apnea, the evidence that addresses the links between sleep apnea and cardiovascular disease, and research that has addressed the effect of sleep apnea treatment on cardiovascular disease and clinical endpoints. Finally, we review the recent development in sleep apnea treatment options, with special consideration of treating patients with heart disease. Future directions for selective areas are suggested.

Association of Positive Airway Pressure With Cardiovascular Events and Death in Adults With Sleep Apnea: A Systematic Review and Meta-analysis

IMPORTANCE

Sleep apnea (obstructive and central) is associated with adverse cardiovascular risk factors and increased risks of cardiovascular disease. Positive airway pressure (PAP) provides symptomatic relief, whether delivered continuously (CPAP) or as adaptive servo-ventilation (ASV), but the associations with cardiovascular outcomes and death are unclear.

OBJECTIVE

To assess the association of PAP vs control with cardiovascular events and death in patients with sleep apnea.

DATA SOURCES AND STUDY SELECTION

MEDLINE, EMBASE, and the Cochrane Library were systematically searched from inception date to March 2017 for randomized clinical trials that included reporting of major adverse cardiovascular events or deaths.

DATA EXTRACTION AND SYNTHESIS

Two authors independently extracted data using standardized forms. Summary relative risks (RRs), risk differences (RDs) and 95% CIs were obtained using random-effects meta-analysis.

MAIN OUTCOMES AND MEASURES

The main outcomes were a composite of acute coronary syndrome (ACS) events, stroke, or vascular death (major adverse cardiovascular events); cause-specific vascular events; and death.

RESULTS

The analyses included data from 10 trials (9 CPAP; 1 ASV) of patients with sleep apnea (N = 7266; mean age, 60.9 [range, 51.5 to 71.1] years; 5847 [80.5%] men; mean [SD] body mass index, 30.0 [5.2]. Among 356 major adverse cardiovascular events and 613 deaths recorded, there was no significant association of PAP with major adverse cardiovascular events (RR, 0.77 [95% CI, 0.53 to 1.13]; P = .19 and RD, -0.01 [95% CI, -0.03 to 0.01]; P = .23), cardiovascular death (RR, 1.15 [95% CI, 0.88 to 1.50]; P = .30 and RD -0.00 [95% CI, -0.02 to 0.02]; P = .87), or all-cause death (RR, 1.13 [95% CI, 0.99 to 1.29]; P = .08 and RD, 0.00 [95% CI, -0.01 to 0.01]; P = .51). The same was true for ACS, stroke, and heart failure. There was no evidence of different associations for CPAP vs ASV (all P value homogeneity >.24), and meta-regressions identified no associations of PAP with outcomes for different levels of apnea severity, follow-up duration, or adherence to PAP (all P values > .13).

CONCLUSIONS AND RELEVANCE

The use of PAP, compared with no treatment or sham, was not associated with reduced risks of cardiovascular outcomes or death for patients with sleep apnea. Although there are other benefits of treatment with PAP for sleep apnea, these findings do not support treatment with PAP with a goal of prevention of these outcomes.

The efficacy of continuous positive airway pressure therapy in reducing cardiovascular events in obstructive sleep apnea: a systematic review

Prospective studies show an association between obstructive sleep apnea and cardiovascular disease. Continuous positive airway pressure (CPAP) is the treatment of choice and effectively reduces subjective sleepiness and apneic and hypopneic events. However, randomized trials have not shown a reduction in cardiovascular outcomes with CPAP therapy. We review the past 10 years of randomized trial evidence regarding the therapeutic efficacy of CPAP on cardiovascular outcomes and mortality in adults with obstructive sleep apnea. The majority of studies found no significant improvement in cardiovascular outcomes with CPAP, although many noted nonsignificant benefits. Adjusted analysis in several trials showed significant cardiovascular benefit in those patients with higher CPAP compliance. Existing trials may lack sufficient follow-up and CPAP compliance, among other limitations.

Noninvasive Ventilatory Correction in Patients With Acute Ischemic Stroke: A Systematic Review and Meta-Analysis

BACKGROUND AND PURPOSE

Even though current guidelines suggest that noninvasive ventilatory correction (NIVC) could be considered for acute ischemic stroke patients with obstructive sleep apnea, available evidence is conflicting, with no adequately powered randomized clinical trial being available to date.

METHODS

We conducted a systematic review and meta-analysis of all available literature data evaluating the effect of NIVC on neurological improvement (based on decrease in National Institutes of Health Stroke Scale score), vascular events (recurrent stroke, transient ischemic attack, myocardial infarction and unstable angina), and mortality during the follow-up period.

RESULTS

We identified 4 randomized clinical trials and 1 prospectively matched observational cohort, comprising a total of 389 patients (59.8% males, mean age: 64.4 years). The risk of both performance and detection bias was considered high in most of the included randomized clinical trials because of the lack of blinding in participants, personnel and/or outcome assessors. The mean decrease in National Institutes of Health Stroke Scale scores during the first (≤30) days of acute ischemic stroke was found to be greater in NIVC-treated patients in comparison to controls (standardized mean difference, 0.38; 95% confidence interval, 0.11-0.66; P=0.007). However, no significant differences were detected between NIVC-treated acute ischemic stroke patients and controls on both the risk of vascular events (risk ratio, 0.53; 95% confidence interval, 0.25-1.14; P=0.11) and mortality (risk ratio, 0.71; 95% confidence interval, 0.37-1.36; P=0.30). No evidence of heterogeneity (I²=0%; P for Cochran Q>0.50) or publication bias were detected in all analyses.

CONCLUSIONS

NIVC seems to be associated with greater short-term neurological improvement in acute ischemic stroke patients with obstructive sleep apnea. This finding deserves further investigation within the settings of an adequately powered, sham-control, randomized clinical trial.

Stroke and other cardiovascular events in patients with obstructive sleep apnea and the effect of continuous positive airway pressure

Obstructive sleep apnea (OSA) is a known-risk factor for cardiovascular diseases. There are indications that treatment with continuous positive airway pressure (CPAP) reduces the risk of new cardiovascular events. In this study, we analyzed the incidence of cardiovascular events in patients with OSA and compared for the impact of CPAP therapy. All polysomnographies performed in 2009 and 2010 were selected with an AHI ≥5 and patients older than 18 years. These 1110 patients were approached with a questionnaire about cardiovascular events and CPAP treatment. Finally, 554 patients were included in analyses. CPAP treatment was based on compliance (level 1 treatment) and extended with residual respiratory events (level 2 treatment). OSA was set as AHI ≥5 and classified in mild (AHI 5-15), moderate (AHI 15-30) and severe (AHI ≥30) OSA. 50 cardiovascular events occurred in 44 patients during follow-up (mean follow-up time 5.9 years) in 554 patients. The events were significantly higher in patients with increasing classification of OSA-severity (p = 0.016). A first-ever cardiovascular event did not differ significantly between mild, moderate and severe OSA. Untreated CPAP patients had significantly more cardiovascular events as compared to treated patients with a hazard ratio of 2.66 partially adjusted for age, AHI and smoking. There was no significant contribution of other cardiovascular risk factors. Patients with OSA with an indication for CPAP treatment have more cardiovascular events when untreated compared to treated patients. This indicates that treatment of OSA by CPAP can reduce the risk for cardiovascular events.

Continuous positive airway pressure therapy in obstuctive sleep apnea: benefits and alternatives

INTRODUCTION

Obstructive sleep apnea (OSA) is a highly prevalent condition affecting persons of all age with an increasing public health burden. It is implicated in cardiovascular disease, metabolic syndrome, neurocognitive impairment, reductions in quality of life, and increased motor vehicle accidents. The goals of OSA treatment are to improve sleep and daytime symptoms, and minimize cardiovascular risks.Areas covered: Continuous positive airway pressure (CPAP) is considered the gold standard therapy that delivers pressurized air into the upper airway to relieve obstruction during sleep. Although CPAP is an effective modality of treatment for OSA, adherence to therapy is highly variable. This article highlights the benefits of CPAP therapy, along with alternative treatment options including oral appliance, implantable and wearable devices, and surgery. Expert commentary: CPAP therapy is the gold standard treatment option and should continue to be offered to those who suffer from OSA. Alternative options are available for those who are unable to adhere to CPAP or choose an alternative treatment modality. The most interesting advances have been incorporating orthodontic procedures in conjunction with myofunctional therapy in prepubertal children, raising the possibility of OSA prevention by initiating treatment early in life.

Critical review: CPAP and weight management of obstructive sleep apnea cardiovascular co-morbidities

The cardiovascular co-morbidities of obstructive sleep apnea (OSA) are similar to those of obesity. Cardiovascular co-morbidities often are the cause of adverse outcomes in overweight/obese OSA patients. Continuous positive airway pressure (CPAP) therapy resolves the symptoms of OSA, but may, or may not lead to improvement of a given cardiovascular co-morbidity. The impact of CPAP on cardiovascular risk variables, adverse cardiovascular events in overweight/obese OSA patients has been evaluated primarily in prospective, uncontrolled cohort studies. These studies show improvement in myocardial and endothelial function, blood pressure, left ventricular performance and stroke survival. Randomized controlled studies (RCTs) examining the effect of weight management on cardiovascular risk factors and disease outcomes show that intentional weight loss leads to improvement in cardiovascular risk, hypertension, coronary artery disease, but not in stroke. Weight loss improves mortality in relatively healthy overweight/obese populations, but possibly not in all groups with cardiometabolic diseases. Clinicians caring for overweight/obese OSA patients should consider the advantages of incorporating weight management into their treatment programs for such patients.

Sleep apnoea and the neurologist

There is increasing awareness and interest in the complex and extensive inter-relationships between sleep disorders and neurological disorders. This review focuses on the clinical interactions between obstructive sleep apnoea and stroke, headaches, epilepsy, cognition and idiopathic Parkinson's disease. We highlight to the neurologist the importance of taking a sleep history and considering the diagnosis and treatment of obstructive sleep apnoea.

Role of sleep-disordered breathing and sleep-wake disturbances for stroke and stroke recovery

Background:

Sleep-disordered breathing (SDB) and sleep-wake disturbances (SWD) are highly prevalent in stroke patients. Recent studies suggest that they represent both a risk factor and a consequence of stroke and affect stroke recovery, outcome, and recurrence.

Methods:

Review of literature.

Results:

Several studies have proven SDB to represent an independent risk factor for stroke. Sleep studies in TIA and stroke patients are recommended in view of the very high prevalence (>50%) of SDB (Class IIb, level of evidence B). Treatment of obstructive SDB with continuous positive airway pressure is recommended given the strength of the increasing evidence in support of a positive effect on outcome (Class IIb, level of evidence B). Oxygen, biphasic positive airway pressure, and adaptive servoventilation may be considered in patients with central SDB. Recently, both reduced and increased sleep duration, as well as hypersomnia, insomnia, and restless legs syndrome (RLS), were also suggested to increase stroke risk. Mainly experimental studies found that SWD may in addition impair neuroplasticity processes and functional stroke recovery. Treatment of SWD with hypnotics and sedative antidepressants (insomnia), activating antidepressants or stimulants (hypersomnia), dopaminergic drugs (RLS), and clonazepam (parasomnias) are based on single case observations and should be used with caution.

Conclusions:

SDB and SWD increase the risk of stroke in the general population and affect short- and long-term stroke recovery and outcome. Current knowledge supports the systematic implementation of clinical procedures for the diagnosis and treatment of poststroke SDB and SWD on stroke units.

The Link Between Obstructive Sleep Apnea and Cardiovascular Disease

Obstructive sleep apnea (OSA) is common in the general population and highly prevalent in patients with cardiovascular disease. In this paper, we review (1) the pathophysiological mechanisms of OSA that may causally contribute to cardiovascular disease; (2) current evidence regarding the association between OSA and hypertension, stroke, ischemic heart disease, heart failure, atrial fibrillation, and cardiovascular mortality; and (3) the impact of continuous positive airway pressure (CPAP) treatment on cardiovascular risk factors and outcomes. We emphasize the importance of obesity as a comorbidity of OSA and a confounder in the association between OSA and cardiovascular disease. We also discuss the importance of addressing obesity in patients with OSA, as a strategy to reduce the burden of cardiovascular risk factors in this population. Implications for the approach of patients' OSA in clinical practice and future research directions are discussed.

[Sleep and neurological diseases]

Knowledge of the physiology of sleep-wake regulation can contribute to an understanding of the pathophysiology and symptoms of neurological diseases and is helpful for initiating specific therapies for sleep-wake cycle stabilization. Based on historically important observations on the close relationship between sleep and neurological diseases, new insights and developments in selected neurological entities are presented in this review article.

Stroke and sleep-disordered breathing: A relationship under construction

The association between sleep-disordered breathing (SDB) and cardiovascular risk has been the focus of attention in recent years. Sleep disorders are emerging risk factors for cardiovascular disease and have been related to the whole spectrum of stroke, including transient ischemic attack, ischemic cerebral infarction and intracerebral haemorrhage. It has been shown that lacunar stroke or lacunar infarctions affecting the internal capsule or the protuberance are associated with a higher frequency of SDB. Acute stroke patients with associated SDB have a worse prognosis and a higher mortality as compared to patients with first-ever stroke without SDB. Preliminary studies provide evidence of the usefulness of treatment with continuous positive airway pressure when SDB is present in stroke patients.

Effect of CPAP therapy on cardiovascular events and mortality in patients with obstructive sleep apnea: a meta-analysis

PURPOSE

Continuous positive airway pressure (CPAP) therapy may decrease the risk of mortality and cardiovascular events in patients with obstructive sleep apnea. However, these benefits are not completely clear.

METHODS

We undertook a meta-analysis of randomized clinical trials identified in systematic searches of MEDLINE, EMBASE, and the Cochrane Database.

RESULTS

Eighteen studies (4146 patients) were included. Overall, CPAP therapy did not significantly decrease the risk of cardiovascular events compared with the control group (odds ratio (OR), 0.84; 95 % confidence intervals (CI), 0.62-1.13; p = 0.25; I (2) = 0 %). CPAP was associated with a nonsignificant trend of lower rate of death and stroke (for death: OR, 0.85; 95 % CI, 0.35-2.06; p = 0.72; I (2) = 0.0 %; for stroke: OR, 0.56; 95 % CI, 0.18-1.73; p = 0.32; I (2) = 12.0 %), a significantly lower Epworth sleepiness score (ESS) (mean difference (MD), -1.78; 95 % CI, -2.31 to -1.24; p < 0.00001; I (2) = 76 %), and a significantly lower 24 h systolic and diastolic blood pressure (BP) (for 24 h systolic BP: MD, -2.03 mmHg; 95 % CI, -3.64 to -0.42; p = 0.01; I (2) = 0 %; for diastolic BP: MD, -1.79 mmHg; 95 % CI, -2.89 to -0.68; p = 0.001; I (2) = 0 %). Daytime systolic BP and body mass index were comparable between the CPAP and control groups. Subgroup analysis did not show any significant difference between short- and mediate-to-long-term follow-up groups with regard to cardiovascular events, death, and stroke.

CONCLUSIONS

CPAP therapy was associated with a trend of decreased risk of cardiovascular events. Furthermore, ESS and BP were significantly lower in the CPAP group. Larger randomized studies are needed to confirm these findings.

Obstructive sleep apnea and hypertension: a critical review

Obstructive sleep apnea (OSA) is a prevalent sleep disorder which is characterized by recurrent upper closure with oxygen desaturation and sleep disruption. OSA increases the risk of vascular disorders in the form of stroke, myocardial infarction, congestive heart failure, and hypertension. The mechanisms underlying the vascular disorders are several and include intermittent hypoxia with release of cytokines, angiogenic inhibitors, free radicals, and adhesion molecules. During apneas, arterial blood pressure gradually rises and surges abruptly after the termination of apnea. Two thirds of patients with OSA will ultimately have diurnal hypertension. This review discusses the literature supporting the significant role of OSA in hypertension and the effect of OSA treatment on blood pressure.

Sleep Apnea and Stroke

Stroke is the second leading cause of death worldwide and often has devastating consequences for affected individuals in terms of chronic disability. Traditional risk factors such as age, male sex, ethnicity, hypertension, and atrial fibrillation explain 60%-80% of the risk of stroke. Obstructive sleep apnea (OSA) is highly prevalent in individuals who have had a stroke and its emerging role as a potential modifiable risk factor for stroke has been recognized in the most recent American Heart Association stroke guidelines, which recommend consideration of screening for and treatment of OSA in this regard. In this article we provide an overview of the current evidence-based knowledge related to stroke and sleep apnea. The main focus of this article is key pathophysiological mechanisms by which OSA might increase the risk for stroke. The effect of OSA on stroke outcomes and the efficacy of treatment of OSA on these outcomes is also discussed.