Unattended Hospital and Home Sleep Apnea Testing Following Cerebrovascular Events

The potential effects of untreated sleep-related breathing disorders on neuropathic pain, spasticity, and cardiovascular dysfunction following spinal cord injury: A cross-sectional prospective study protocol

INTRODUCTION

Sleep-related breathing disorders (SRBDs), neuropathic pain, spasticity and cardiovascular autonomic dysfunction are common after spinal cord injury (SCI). Prior studies suggest that systemic inflammation following SCI may be implicated in the development of neuropathic pain, spasticity and cardiovascular dysfunction. Given that SRBDs also cause a systemic inflammatory response, we hypothesized that individuals with SCI who develop more severe SRBDs would experience more intense neuropathic pain, more severe spasticity and more significant cardiovascular autonomic dysfunction.

METHODS

This cross-sectional prospective study will explore the previously understudied hypothesis that SRBDs are associated with increased neuropathic pain, spasticity, and cardiovascular autonomic dysfunction in adult individuals with low-cervical/high-thoracic (injury level at C5 to T6), complete/incomplete (ASIA Impairment Scale A, B, C or D) SCI.

DISCUSSION

To our knowledge, no prior study has addressed this clinically relevant question on whether the degree of SRBDs affects the intensity of neuropathic pain, spasticity, and cardiovascular autonomic dysfunction in individuals with SCI. We anticipate that the results of this original study will provide key information for a future clinical trial on the use of continuous positive airway pressure (CPAP) therapy for moderate-to-severe SRBDs, which may better control neuropathic pain, spasticity, and cardiovascular autonomic dysfunction among individuals with SCI.

TRIAL REGISTRATION

The research protocol for this study was registered in the ClinicalTrials.gov website (NCT05687097). https://clinicaltrials.gov/ct2/show/NCT05687097.

A systematic review on the association of sleep-disordered breathing with cardiovascular pathology in adults

Sleep-disordered breathing (SDB) is characterized by repeated breathing pauses during sleep. The prevalence of SDB varies widely between studies. Some longitudinal studies have found an association of SDB with incident or recurrent cardiovascular events. We sought to systematically describe the current data on the correlation between SDB and cardiovascular pathology. Studies were included if they were original observational population-based studies in adults with clearly diagnosed SDB. The primary outcomes include all types of cardiovascular pathology. We carried out pooled analyses using a random effects model. Our systematic review was performed according to the PRISMA and MOOSE guidelines for systematic reviews and was registered with PROSPERO. In total, 2652 articles were detected in the databases, of which 76 articles were chosen for full-text review. Fourteen studies were focused on samples of an unselected population, and 8 studies were focused on a group of persons at risk for SDB. In 5 studies, the incidence of cardiovascular pathology in the population with SDB was examined. In total, 49 studies described SDB in patients with cardiovascular pathology. We found an association between SDB and prevalent /incident cardiovascular disease (pooled OR 1.76; 95% CI 1.38–2.26), and pooled HR (95% CI 1.78; 95% CI 1.34–2.45). Notably, in patients with existing SDB, the risk of new adverse cardiovascular events was high. However, the relationship between cardiovascular disease and SDB is likely to be bidirectional. Thus, more large-scale studies are needed to better understand this association and to decide whether screening for possible SDB in cardiovascular patients is reasonable and clinically significant.

Sleep apnoea and ischaemic stroke: current knowledge and future directions

Sleep apnoea, one of the most common chronic diseases, is a risk factor for ischaemic stroke, stroke recurrence, and poor functional recovery after stroke. More than half of stroke survivors present with sleep apnoea during the acute phase after stroke, with obstructive sleep apnoea being the most common subtype. Following a stroke, sleep apnoea frequency and severity might decrease over time, but moderate to severe sleep apnoea is nevertheless present in up to a third of patients in the chronic phase after an ischaemic stroke. Over the past few decades evidence suggests that treatment for sleep apnoea is feasible during the acute phase of stroke and might favourably affect recovery and long-term outcomes. Nevertheless, sleep apnoea still remains underdiagnosed and untreated in many cases, due to challenges in the detection and prediction of post-stroke sleep apnoea, uncertainty as to the optimal timing for its diagnosis, and a scarcity of clear treatment guidelines (ie, uncertainty on when to treat and the optimal treatment strategy). Moreover, the pathophysiology of sleep apnoea associated with stroke, the proportion of stroke survivors with obstructive and central sleep apnoea, and the temporal evolution of sleep apnoea subtypes following stroke remain to be clarified. To address these shortcomings, the management of sleep apnoea associated with stroke should be integrated into a multidisciplinary diagnostic, treatment, and follow-up strategy.

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

BACKGROUND AND PURPOSE

Poststroke/transient ischemic attack obstructive sleep apnea (OSA) is prevalent, linked with numerous unfavorable health consequences, but remains underdiagnosed. Reasons include patient inconvenience and costs associated with use of in-laboratory polysomnography (iPSG), the current standard tool. Fortunately, home sleep apnea testing (HSAT) can accurately diagnose OSA and is potentially more convenient and cost-effective compared with iPSG. Our objective was to assess whether screening for OSA in patients with stroke/transient ischemic attack using HSAT, compared with standard of care using iPSG, increased diagnosis and treatment of OSA, improved clinical outcomes and patient experiences with sleep testing, and was a cost-effective approach.

METHODS

We consecutively recruited 250 patients who had sustained a stroke/transient ischemic attack within the past 6 months. Patients were randomized (1:1) to use of (1) HSAT versus (2) iPSG. Patients completed assessments and questionnaires at baseline and 6-month follow-up appointments. Patients diagnosed with OSA were offered continuous positive airway pressure. The primary outcome was compared between study arms via an intention-to-treat analysis.

RESULTS

At 6 months, 94 patients completed HSAT and 71 patients completed iPSG. A significantly greater proportion of patients in the HSAT arm were diagnosed with OSA (48.8% versus 35.2%, P=0.04) compared with the iPSG arm. Furthermore, patients assigned to HSAT, compared with iPSG, were more likely to be prescribed continuous positive airway pressure (40.0% versus 27.2%), report significantly reduced sleepiness, and a greater ability to perform daily activities. Moreover, a significantly greater proportion of patients reported a positive experience with sleep testing in the HSAT arm compared with the iPSG arm (89.4% versus 31.1%). Finally, a cost-effectiveness analysis revealed that HSAT was economically attractive for the detection of OSA compared with iPSG.

CONCLUSIONS

In patients with stroke/transient ischemic attack, use of HSAT compared with iPSG increases the rate of OSA diagnosis and treatment, reduces daytime sleepiness, improves functional outcomes and experiences with sleep testing, and could be an economically attractive approach.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02454023.

Prevalence and Determinants of Sleep Apnea in Patients with Stroke: A Meta-Analysis

OBJECTIVES

Recent meta-analyses have noted that ∼70% of transient ischemic attack (TIA)/stroke patients have sleep apnea. However, the heterogeneity between studies was high and did not appear to be accounted by the phase of stroke. We conducted an updated meta-analysis and aimed to determine whether the prevalence of sleep apnea amongst stroke patients differs by the subtype, etiology, severity and location of stroke and hence could account for some of the unexplained heterogeneity observed in previous studies.

MATERIALS AND METHODS

We searched Medline, Embase, CINAHL and Cochrane Library (from their commencements to July 2020) for studies which reported the prevalence of sleep apnea by using polysomnography in TIA/stroke patients. We used random-effects model to calculate the pooled prevalence of sleep apnea and explored whether the prevalence differed by stroke characteristics.

RESULTS

Seventy-five studies describing 8670 stroke patients were included in this meta-analysis. The overall prevalence of sleep apnea was numerically higher in patients with hemorrhagic vs. ischemic stroke [82.7% (64.4-92.7%) vs. 67.5% (63.2-71.5%), p=0.098], supratentorial vs. infratentorial stroke [64.4% (56.7-71.4%) vs. 56.5% (42.2-60.0%), p=0.171], and cardioembolic [74.3% (59.6-85.0%)] vs. other ischemic stroke subtypes [large artery atherosclerosis: 68.3% (52.5-80.7%), small vessel occlusion: 56.1% (38.2-72.6%), others/undetermined: 47.9% (31.6-64.6%), p=0.089]. The heterogeneity in sleep apnea prevalence was partially accounted by the subtype (1.9%), phase (5.0%) and location of stroke (14.0%) among reported studies.

CONCLUSIONS

The prevalence of sleep apnea in the stroke population appears to differ by the subtype, location, etiology and phase of stroke.

Feasibility of unattended home sleep apnea testing in a cognitively impaired clinic population

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) increases the risk of developing dementia. Home sleep apnea testing (HSAT) is a convenient and validated method to screen for OSA among cognitively well individuals; however, it is unknown if it is a clinically feasible and practical approach in clinic patients with cognitive impairment. We evaluated if HSAT was a feasible and practical approach to screen for OSA in clinic patients with cognitive impairment.

METHODS

Patients with cognitive impairment due to neurodegenerative and/or vascular etiologies completed OSA screening using HSAT. HSAT was considered a feasible technique if ≥ 80% of those who attempted HSAT obtained analyzable data (ie, ≥ 4 hours of flow, effort, and oxygen evaluation), and a practical technique if ≥ 50% of all patients approached for study inclusion obtained analyzable data.

RESULTS

Of the 119 patients who were approached for participation, 83 were enrolled and offered HSAT; 5 did not complete HSAT screening, and the remaining 78 patients attempted HSAT; mean age (± standard deviation) of 72.86 (± 9.89) years and 46% were male. In those that attempted HSAT, 85.9% (67/78) obtained analyzable data and 56.3% (67/119) of eligible patients approached for study inclusion obtained analyzable data.

CONCLUSIONS

HSAT is a feasible and practical technique in a clinic population with cognitive impairment. As OSA is a modifiable risk factor for patients with dementia, HSAT has the potential to lead to expedited treatment for OSA, which may potentially improve health-related outcomes such as cognition.

Trials in Sleep Apnea and Stroke: Learning From the Past to Direct Future Approaches

Few randomized controlled trials have evaluated the effectiveness of continuous positive airway pressure (CPAP) in reducing recurrent vascular events and mortality in poststroke obstructive sleep apnea (OSA). To date, results have been mixed, most studies were underpowered and definitive conclusions are not available. Using lessons learned from prior negative trials in stroke, we reappraise prior randomized controlled trials that examined the use of CPAP in treating poststroke OSA and propose the following considerations: (1) Intervention-based changes, such as ensuring that patients are using CPAP for at least 4 hours per night (eg, through use of improvements in CPAP technology that make it easier for patients to use), as well as considering alternative treatment strategies for poststroke OSA; (2) Population-based changes (ie, including stroke patients with severe and symptomatic OSA and CPAP noncompliers); and (3) Changes to timing of intervention and follow-up (ie, early initiation of CPAP therapy within the first 48 hours of stroke and long-term follow-up calculated in accordance with sample size to ensure adequate power). Given the burden of vascular morbidity and mortality in stroke patients with OSA, there is a strong need to learn from past negative trials and explore innovative stroke prevention strategies to improve stroke-free survival.

EAN/ERS/ESO/ESRS statement on the impact of sleep disorders on risk and outcome of stroke

Sleep disorders are highly prevalent in the general population and may be linked in a bidirectional fashion to stroke, which is one of the leading causes of morbidity and mortality.Four major scientific societies established a task force of experts in neurology, stroke, respiratory medicine, sleep medicine and methodology, to critically evaluate the evidence regarding potential links and the impact of therapy. 13 research questions were evaluated in a systematic literature search using a stepwise hierarchical approach: first, systematic reviews and meta-analyses; second, primary studies post-dating the systematic reviews/meta-analyses. A total of 445 studies were evaluated and 88 included. Statements were generated regarding current evidence and clinical practice.Severe obstructive sleep apnoea (OSA) doubles the risk for incident stroke, especially in young to middle-aged patients. Continuous positive airway pressure (CPAP) may reduce stroke risk, especially in treatment-compliant patients. The prevalence of OSA is high in stroke patients and can be assessed by polygraphy. Severe OSA is a risk factor for recurrence of stroke and may be associated with stroke mortality, while CPAP may improve stroke outcome. It is not clear if insomnia increases stroke risk, while pharmacotherapy of insomnia may increase it. Periodic limb movements in sleep (PLMS), but not restless limb syndrome (RLS), may be associated with an increased risk of stroke. Preliminary data suggest a high frequency of post-stroke insomnia and RLS and their association with a less favourable stroke outcome, while treatment data are scarce.Overall, the evidence base is best for OSA relationship with stroke and supports active diagnosis and therapy. Research gaps remain especially regarding insomnia and RLS/PLMS relationships with stroke.

Obstructive Sleep Apnea in Pregnant Women: A Review of Pregnancy Outcomes and an Approach to Management

Among obese pregnant women, 15%-20% have obstructive sleep apnea (OSA) and this prevalence increases along with body mass index and in the presence of other comorbidities. Prepregnancy obesity and pregnancy-related weight gain are certainly risk factors for sleep-disordered breathing in pregnancy, but certain physiologic changes of pregnancy may also increase a woman's risk of developing or worsening OSA. While it has been shown that untreated OSA in postmenopausal women is associated with a range of cardiovascular, pulmonary, and metabolic comorbidities, a body of literature is emerging that suggests OSA may also have serious implications for the health of mothers and fetuses during and after pregnancy. In this review, we discuss the following: pregnancy as a vulnerable period for the development or worsening of OSA; the associations between OSA and maternal and fetal outcomes; the current screening modalities for OSA in pregnancy; and current recommendations regarding peripartum management of OSA.

Evaluation of an OSA risk stratifying and treatment protocol during inpatient rehabilitation of post-stroke patients

PURPOSE

To evaluate outcomes, outside of a clinical trial setting, of a protocol utilizing overnight oximetry (NOx) to risk stratify post-stroke patients for obstructive sleep apnea (OSA) followed by autoadjusting continuous positive airway pressure (APAP) treatment in patients considered high risk for OSA.

METHODS

Retrospective observational study of post-stroke patients at an academic inpatient stroke rehabilitation facility. Patients underwent NOx, and those at high risk for OSA (oxygen desaturation index 3% > 10 per hour) were attempted on a trial of APAP, and further stratified into high risk adherent with treatment (HRAT) or high-risk failed treatment (HRFT). Change in functional independence measure (FIM) was used to assess recovery.

RESULTS

Two hundred twenty-four post-stroke patients underwent NOx, with 120 (53%) considered high risk for OSA. Twelve (10%) were compliant with APAP treatment (> 4 h/night on > 70% of nights). No difference in change in FIM scores was observed for HRAT versus HRFT [total FIM change - 5.8, 95% CI (- 13.9, 2.2); motor FIM change - 4.5, 95% CI (- 11.5, 2.4); cognitive FIM change - 1.3, 95% CI (-3.8, 1.2)]. A subgroup analysis matched 14 HRAT patients (using adherence criterion of APAP usage > 50% of nights) to 35 HRFT patients. A statistically significant, but clinically irrelevant, difference in total FIM change was observed (HRAT vs HRFT, difference between means - 5.2, p = 0.03).

CONCLUSIONS

The use of APAP in high-risk patients was poorly tolerated and did not improve post-stroke recovery. Further studies with larger sample sizes are needed to determine the effect of APAP treatment on short-term recovery.

Sleep and Stroke: New Updates on Epidemiology, Pathophysiology, Assessment, and Treatment

PURPOSE OF REVIEW

This review aims to discuss the most recent data on sleep disorders and stroke, highlighting relevant findings for the practicing neurologist or health providers who encounter patients with sleep disorders and stroke.

RECENT FINDINGS

Sleep apnea and abnormal sleep duration have the strongest association with stroke risk. Possible mechanisms include non-dipping of blood pressure during sleep, hypoxemia or reoxygenation leading to sympathetic activation, hypertension, atrial fibrillation and impaired cerebral hemodynamics. Treatment studies suggest that continuous positive airway pressure (CPAP) for sleep apnea could improve primary prevention of stroke, but data is equivocal for secondary prevention. However, CPAP could improve functional outcomes after stroke.

SUMMARY

Sleep disorders present an opportunity to improve stroke risk and functional outcomes. However, new strategies are needed to determine the patients at high-risk who would most likely benefit from targeted care. Novel methods for phenotyping sleep disorders could provide personalized stroke care to improve clinical outcomes and public health strategies.

Prevalence of sleep-disordered breathing after stroke and TIA: A meta-analysis

OBJECTIVE

To perform a systematic review and meta-analysis on the prevalence of sleep-disordered breathing (SDB) after stroke.

METHODS

We searched PubMed, Embase (Ovid), the Cochrane Library, and CINAHL (from their commencements to April 7, 2017) for clinical studies reporting prevalence and/or severity of SDB after stroke or TIA. Only sleep apnea tests performed with full polysomnography and diagnostic devices of the American Academy of Sleep Medicine categories I-IV were included. We conducted random-effects meta-analysis. PROSPERO registration number: CRD42017072339.

RESULTS

The initial search identified 5,211 publications. Eighty-nine studies (including 7,096 patients) met inclusion criteria. Fifty-four studies were performed in the acute phase after stroke (after less than 1 month), 23 studies in the subacute phase (after 1-3 months), and 12 studies in the chronic phase (after more than 3 months). Mean apnea-hypopnea index was 26.0/h (SD 21.7-31.2). Prevalence of SDB with apnea-hypopnea index greater than 5/h and greater than 30/h was found in 71% (95% confidence interval 66.6%-74.8%) and 30% (95% confidence interval 24.4%-35.5%) of patients, respectively. Severity and prevalence of SDB were similar in all examined phases after stroke, irrespective of the type of sleep apnea test performed. Heterogeneity between studies (I ²) was mostly high.

CONCLUSION

The high prevalence of SDB after stroke and TIA, which persists over time, is important in light of recent studies reporting the (1) feasibility and (2) efficacy of SDB treatment in this clinical setting.

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

PURPOSE

Obstructive sleep apnea (OSA) is a risk factor and common morbidity for stroke and transient ischemic attack (TIA). However, screening for OSA in patients with stroke or TIA is uncommonly performed, due in part to difficulties associated with conducting polysomnography (PSG) and Home Sleep Apnea Tests (HSATs). The 8-point "STOP-BANG" questionnaire has been shown to have high methodological quality in screening for OSA. This study examined the clinical utility of a modified version of the "STOP-BANG" questionnaire, which removed neck circumference and included nocturnal oxygen desaturation in diagnosing OSA (ie, the "STOP-BAG-O" tool), with the goal of improving uptake and accuracy in diagnosing OSA.

METHODS

In total, 231 participants completed both the STOP-BAG questionnaire and PSG or HSAT within 12 months of stroke/TIA. Using receiver-operating curves, scores on the "STOP-BAG-O" and "STOP-BAG" questionnaires were assessed for their ability to predict a diagnosis of OSA and classify at least 50% of the study population.

RESULTS

Compared to an OSA diagnosis of AHI≥10, the STOP-BAG (using cut-offs of ≤3 and ≥4) had a sensitivity and specificity of 83.5% and 67.2%, respectively. The STOP-BAG-O (using cut-offs of ≤3 and ≥5) had a sensitivity and specificity of 95.9% and 78.4%, respectively. For all AHI cut-offs used, the area under the curve for the STOP-BAG-O was greater and statistically different (p < 0.001) than that for the STOP-BAG.

CONCLUSIONS

The STOP-BAG-O is a valid tool for identifying risk of OSA post-stroke/TIA. The simplicity of this tool and ease of assessing nocturnal oxygen desaturation makes it a feasible option for widespread use.

Predictors of CPAP adherence following stroke and transient ischemic attack

OBJECTIVE

Continuous positive airway pressure (CPAP) has been shown to improve functional, motor and cognitive outcomes in post-stroke obstructive sleep apnea (OSA). However, rates of CPAP adherence are often low and factors impacting CPAP adherence remain under-explored. Our objective was to determine predictors of CPAP adherence in patients who had a stroke or transient ischemic attack (TIA).

METHODS

We screened 313 stroke/TIA patients for OSA using in-hospital polysomnography or the ApneaLink home sleep apnea test. Potential predictors were recorded at baseline and adherence to CPAP was recorded during a six-month follow-up visit. Selected variables from our univariate analyses were included in multivariate regression models to determine predictors of CPAP adherence. For our logistic regression analyses, CPAP adherence (CPAP use of ≥4 h per night) was the dependent outcome variable. In our linear regression analyses, total CPAP use per week (recorded in hours) was the dependent outcome variable.

RESULTS

Eighty-eight patients (mean age 67.81 ± 13.09 years, 69.32% male, mean body mass index 27.93 ± 5.23 kg/m²) were diagnosed with OSA, prescribed CPAP, and assessed for adherence at a six-month follow-up visit. In these 88 patients, 46 (52.27%) were adherent with CPAP therapy. From our regression models, two significant predictors of CPAP adherence were identified: greater functional status (p = 0.04) and not endorsing daytime tiredness (p = 0.047) post-stroke/TIA.

CONCLUSION

Patients with greater functional capacity and those with less daytime fatigue demonstrated stronger adherence to CPAP therapy. Our findings may facilitate future treatment strategies for enhancing CPAP adherence in the vulnerable stroke/TIA population.

Home Sleep Apnea Testing is a Feasible and Accurate Method to Diagnose Obstructive Sleep Apnea in Stroke Patients During In-Hospital Rehabilitation

STUDY OBJECTIVES

To study the feasibility and accuracy of home sleep apnea testing (HSAT) in the diagnosis of obstructive sleep apnea (OSA) in a stroke rehabilitation unit.

METHODS

Stroke patients referred to a neurorehabilitation center underwent OSA screening by means of HSAT within the Home Polygraphic Recording with Telemedicine Monitoring for Diagnosis and Treatment of Sleep Apnea in Stroke, or HOPES study (ClinicalTrials.gov identifier: NCT02748681). Feasibility was determined by evaluating the acceptability of recording quality. Patients in whom moderate OSA was diagnosed subsequently underwent unattended polysomnography (PSG) confirmation. Accuracy was studied by comparing the respiratory event index (REI)/monitoring time (MT) of screening HSAT with the apnea-hypopnea index (AHI)/total sleep time (TST) obtained during subsequent PSG with Bland-Altman plots. The influence of PSG-evaluated wake time and arousals on OSA classification was studied by comparing the AHI and REI of the same night.

RESULTS

A total of 265 patients (58 ± 9 years, 70% male) were screened. A total of 92% of HSAT studies were performed with acceptable recording quality. In total, 33 patients (63 ± 5 years, 58% male) with moderate OSA (REI ≥ 15 to < 30 events/h) were included in the HSAT/PSG comparison. The Bland-Altman plot shows acceptable limits of agreement from -19.5 to +16.4, with a mean difference of -1.33. The REI detected in the PSG night demonstrated no significant differences to the AHI and a high correlation (r = .97; P < .001). The 95% confidence interval of the Bland-Altman plots varied from -7.61 to +4.80.

CONCLUSIONS

These findings confirm a good feasibility and sufficient accuracy of HSAT attached in a stroke rehabilitation unit. Therefore, the authors suggest that American Academy of Sleep Medicine recommendations for HSAT should include stroke patients.

Methodological strategies in using home sleep apnea testing in research and practice

PURPOSE

Home sleep apnea testing (HSAT) has increased due to improvements in technology, accessibility, and changes in third party reimbursement requirements. Research studies using HSAT have not consistently reported procedures and methodological challenges. This paper had two objectives: (1) summarize the literature on use of HSAT in research of adults and (2) identify methodological strategies to use in research and practice to standardize HSAT procedures and information.

METHODS

Search strategy included studies of participants undergoing sleep testing for OSA using HSAT. MEDLINE via PubMed, CINAHL, and Embase with the following search terms: "polysomnography," "home," "level III," "obstructive sleep apnea," and "out of center testing."

RESULTS

Research articles that met inclusion criteria (n = 34) inconsistently reported methods and methodological challenges in terms of: (a) participant sampling; (b) instrumentation issues; (c) clinical variables; (d) data processing; and (e) patient acceptability. Ten methodological strategies were identified for adoption when using HSAT in research and practice.

CONCLUSIONS

Future studies need to address the methodological challenges summarized in this paper as well as identify and report consistent HSAT procedures and information.

Ambulatory screening for obstructive sleep apnea in patients with resistant arterial hypertension

OBJECTIVE

Obstructive sleep apnea (OSA) is one of the most common causes of secondary arterial hypertension. It is important to rule out OSA as a cause of resistant hypertension. The ApneaLink device is a simple and cost-efficient outpatient examination, but its usefulness in screening OSA in resistant hypertension has not yet been evaluated.

METHODS

A total of 69 patients with resistant arterial hypertension were enrolled. Patients underwent a physical examination, including the use of ApneaLink, followed by respiratory polygraphy. The presence of OSA was assessed by the apnea-hypopnea index (AHI), oxygen desaturation index (ODI), mean nocturnal desaturation (SpO₂), and percentage of sleep time with SpO₂ less than 90%.

RESULTS

There was no significant difference between the values of AHI found during the use of ApneaLink and respiratory polygraphy (mean 30.4 ± 21.7 vs. 37.2 ± 20.9, P = 0.07). ApneaLink had 77.3% sensitivity and 100% specificity to diagnose OSA with the area under the ROC curve 0.866 (P < 0.001). We also found no significant difference in mean SpO₂ (91.3 ± 2.5 vs. 90.9 ± 3.3%, P = 0.22). The ODI evaluated via ApneaLink was significantly lower than by the polygraphy (31.1 ± 18.3 vs. 43.9 ± 24.8, P < 0.001), while the measured percentage of sleep time with SpO₂ less than 90% was higher (31.8 ± 23.7 vs. 23.3 ± 24.4, P = 0.001). The severity of OSA was correctly determined by ApneaLink in 50.7% of patients, underestimated in 23.2% and overestimated in 26.1%.

CONCLUSIONS

The use of ApneaLink is a suitable method for screening the presence of OSA in patients with resistant hypertension, but to accurately assess the severity of OSA, respiratory polygraphy or polysomnography is required.