Diagnostic accuracy of overnight oximetry for the diagnosis of sleep-disordered breathing in atrial fibrillation patients

Obstructive Sleep Apnea and Stroke: Determining the Mechanisms Behind their Association and Treatment Options

Sleep-disordered breathing (SDB) can be a sequela of stroke caused by vascular injury to vital respiratory centers, cerebral edema, and increased intracranial pressure of space-occupying lesions. Likewise, obstructive sleep apnea (OSA) contributes to increased stroke risk through local mechanisms such as impaired ischemic cerebrovascular response and systemic effects such as promoting atherosclerosis, hypercoagulability, cardiac arrhythmias, vascular-endothelial dysfunction, and metabolic syndrome. The impact of OSA on stroke outcomes has been established, yet it receives less attention in national guidelines on stroke management than hyperglycemia and blood pressure dysregulation. Furthermore, whether untreated OSA worsens stroke outcomes is not well-described in the literature. This scoping review provides an updated investigation of the correlation between OSA and stroke, including inter-relational pathophysiology. This review also highlights the importance of OSA treatment and its role in stroke outcomes. Knowledge of pathophysiology, the inter-relationship between these common disorders, and the impact of OSA therapy on outcomes affect the clinical management of patients with acute ischemic stroke. In addition, understanding the relationship between stroke outcomes and pre-existing OSA will allow clinicians to predict outcomes while treating acute stroke.

Recommended assessment and management of sleep disordered breathing in patients with atrial fibrillation, hypertension and heart failure: Taiwan Society of Cardiology/Taiwan Society of sleep Medicine/Taiwan Society of pulmonary and Critical Care Medicine joint consensus statement

Sleep disordered breathing (SDB) is highly prevalent and may be linked to cardiovascular disease in a bidirectional manner. The Taiwan Society of Cardiology, Taiwan Society of Sleep Medicine and Taiwan Society of Pulmonary and Critical Care Medicine established a task force of experts to evaluate the evidence regarding the assessment and management of SDB in patients with atrial fibrillation (AF), hypertension and heart failure with reduced ejection fraction (HFrEF). The GRADE process was used to assess the evidence associated with 15 formulated questions. The task force developed recommendations and determined strength (Strong, Weak) and direction (For, Against) based on the quality of evidence, balance of benefits and harms, patient values and preferences, and resource use. The resulting 11 recommendations are intended to guide clinicians in determining which the specific patient-care strategy should be utilized by clinicians based on the needs of individual patients.

Yield of overnight pulse oximetry in screening commercial drivers for obstructive sleep apnea

PURPOSE

To assess the efficacy of overnight pulse oximetry in screening male commercial drivers (CDs) for obstructive sleep apnea (OSA).

METHODS

Consecutive male CDs undergoing their annual scheduled occupational health visit were enrolled from ten transportation facilities. All subjects underwent a home sleep apnea test (HSAT) to determine the Respiratory Event Index (REI). Oxygen desaturation indices (ODIs) below the 3% and 4% thresholds were computed using the built-in HSAT pulse oximeter. We then assessed the association between ODI values and the presence of OSA (defined as an REI ≥ 5 events/hour) as well as moderate to severe OSA (REI ≥ 15 events/hour).

RESULTS

Of 331 CDs recruited, 278 (84%) completed the study protocol and 53 subjects were excluded due to inadequate HSAT quality. The included and excluded subjects were comparable in demographics and clinical characteristics. The included CDs had a median age of 49 years (interquartile range (IQR) = 15 years) and a median body mass index of 27 kg/m2 (IQR = 5 kg/m2). One hundred ninety-nine (72%) CDs had OSA, of which 48 (17%) were with moderate OSA and 45 (16%) with severe OSA. The ODI3 and ODI4 receiving operating characteristic curve value were 0.95 for predicting OSA and 0.98-0.96 for predicting moderate to severe OSA.

CONCLUSION

Overnight oxygen oximetry may be an effective means to screen CDs for OSA.

Repurposing catheter ablation work-up to detect expiratory airflow limitation in patients with atrial fibrillation

Background

In atrial fibrillation (AF) patients, presence of expiratory airflow limitation may negatively impact treatment outcomes. AF patients are not routinely screened for expiratory airflow limitation, but existing examinations can help identify at-risk individuals. We aimed to assess the diagnostic value of repurposing existing assessments from the pre-ablation work-up to identify and understand the characteristics of affected patients.

Methods

We screened 110 consecutive AF patients scheduled for catheter ablation with handheld spirometry. Routine pre-ablation work-up included cardiac computed tomographic angiography (CCTA), transthoracic echocardiography and polygraphy. CCTA was analyzed qualitatively for emphysema and airway abnormalities. Multivariate logistic regression analysis was performed to determine predictors of expiratory airflow limitation.

Results

We found that 25 % of patients had expiratory airflow limitation, which was undiagnosed in 86 % of these patients. These patients were more likely to have pulmonary abnormalities on CCTA, including emphysema (odds ratio [OR] 4.2, 95 % confidence interval [CI] 1.12-15.1, p < 0.05) and bronchial wall thickening (OR 2.6, 95 % CI 1.0-6.5, p < 0.05). The absence of pulmonary abnormalities on CCTA accurately distinguished patients with normal lung function from those with airflow limitation (negative predictive value: 85 %). Echocardiography and polygraphy did not contribute significantly to identifying airflow limitation.

Conclusions

In conclusion, routine pre-ablation CCTA can detect pulmonary abnormalities in AF patients with airflow limitation, guiding further pulmonary assessment. Future studies should investigate its impact on ablation procedure success.

International Consensus Statement on Obstructive Sleep Apnea

BACKGROUND

Evaluation and interpretation of the literature on obstructive sleep apnea (OSA) allows for consolidation and determination of the key factors important for clinical management of the adult OSA patient. Toward this goal, an international collaborative of multidisciplinary experts in sleep apnea evaluation and treatment have produced the International Consensus statement on Obstructive Sleep Apnea (ICS:OSA).

METHODS

Using previously defined methodology, focal topics in OSA were assigned as literature review (LR), evidence-based review (EBR), or evidence-based review with recommendations (EBR-R) formats. Each topic incorporated the available and relevant evidence which was summarized and graded on study quality. Each topic and section underwent iterative review and the ICS:OSA was created and reviewed by all authors for consensus.

RESULTS

The ICS:OSA addresses OSA syndrome definitions, pathophysiology, epidemiology, risk factors for disease, screening methods, diagnostic testing types, multiple treatment modalities, and effects of OSA treatment on multiple OSA-associated comorbidities. Specific focus on outcomes with positive airway pressure (PAP) and surgical treatments were evaluated.

CONCLUSION

This review of the literature consolidates the available knowledge and identifies the limitations of the current evidence on OSA. This effort aims to create a resource for OSA evidence-based practice and identify future research needs. Knowledge gaps and research opportunities include improving the metrics of OSA disease, determining the optimal OSA screening paradigms, developing strategies for PAP adherence and longitudinal care, enhancing selection of PAP alternatives and surgery, understanding health risk outcomes, and translating evidence into individualized approaches to therapy.

Transvenous phrenic nerve stimulation for the treatment of central sleep apnea reduces episodic hypoxemic burden

STUDY OBJECTIVES

To determine the effect of transvenous phrenic nerve stimulation (TPNS) on the composition of the nocturnal hypoxemic burden in patients with CSA.

METHODS

We analysed oximetry data from baseline and follow-up overnight polysomnograms (PSG) in 134 CSA patients with implanted TPNS randomised (1:1) to neurostimulation (treatment group; TPNS on) or no stimulation (control group; TPNS off) from the remedē System Pivotal Trial. The hypoxemic burden was quantified using a battery of metrics, including the oxygen desaturation index (ODI), the relative sleep time spent below 90% SpO2 (T90) due to acute episodic desaturations (T90_desat) and due to non-specific and non-cyclic drifts of SpO2 (T90_non-specific). Mean change from baseline is provided.

RESULTS

TPNS titrated to reduce respiratory events significantly reduced the ODI in the treatment group by -15.85 h^-1 ± 1.99 compared to the control group, which increased 1.32 h^-1 ± 1.85 (p 〈0001) and shortened the relative T90 duration by -3.81 percentage points ± 1.23 vs. 0.49 percentage points ± 1.14 increase (p = 0.012). This shortening of T90 was primarily accomplished by reducing the brief cyclic desaturations (T90_desaturation: -4.32 percentage points ± 0.98 vs. 0.52 percentage points ± 0.91, p = 0.0004) while notable non-specific drifts in SpO₂ remained unchanged (T90_non-specific: 0.18 percentage points ± 0.62 vs. -0.13 percentage points ± 0.57, p = 0.72).

CONCLUSIONS

TPNS appears to significantly reduce the nocturnal hypoxemic burden due to sleep-disordered breathing, but a considerable nocturnal hypoxemic burden from other sources remains. Further investigations are warranted to identify the best strategy to reduce the nocturnal hypoxemic burden beyond preventing respiratory events.

No Difference in Sleep Desaturations Severity between Patients with Wake-Up and Non-Wake-Up Stroke: A PRESS Study Results

BACKGROUND

Wake-up stroke (WUS) is a certain type of ischemic stroke in which a patient wakes up with a new neurological deficit due to cerebral ischemia. Sleep-disordered breathing is an independent risk factor for stroke, but the role of nocturnal oxygen desaturation in the pathophysiology of WUS is still insufficiently explored. According to several studies, patients with WUS have a significantly more severe sleep apnea syndrome and lower mean blood oxygen saturation. This study aimed to assess the severity of nocturnal desaturations in acute WUS and non-WUS patients using nocturnal pulse oximetry.

MATERIAL AND METHODS

The cohort of 225 consecutive patients with neuroimaging-verified acute cerebral ischemia was prospectively enrolled. For further analyses, 213 subjects with known WUS/non-WUS status were selected (111 males and 102 females, average age 70.4 ±12.9, median baseline NIHSS = 5, median baseline mRS = 3). Patients were divided into the WUS group (n = 45) and the non-WUS group (n = 168). Overnight pulse oximetry was performed within 7 days of the stroke onset and data of both of the studied groups were compared.

RESULTS

We found oxygen desaturation index (ODI) in the WUS group was 14.5 vs. 16.6 (p = 0.728) in the non-WUS group, basal O2 saturation was 92.2% vs. 92.5% (p = 0.475), average low O2 saturation was 90.3% vs. 89.6% (p = 0.375), minimal O2 saturation was 79.5% vs. 80.6% (p = 0.563), and time with O2 saturation <90% (T90) was 4.4% vs. 4.7% (p = 0.729).

CONCLUSIONS

In the studied sample, monitored respiratory parameters including ODI, basal O2 saturation, average low O2 saturation, minimal O2 saturation, and T90 did not significantly differ between groups of WUS and non-WUS patients.

Sleep characterization with smart wearable devices: a call for standardization and consensus recommendations

The general public increasingly adopts smart wearable devices to quantify sleep characteristics and dedicated devices for sleep assessment. The rapid evolution of technology has outpaced the ability to implement validation approaches and demonstrate relevant clinical applicability. There are untapped opportunities to validate and refine consumer devices in partnership with scientists in academic institutions, patients, and the private sector to allow effective integration into clinical management pathways and facilitate trust in adoption once reliability and validity have been demonstrated. We call for the formation of a working group involving stakeholders from academia, clinical care and industry to develop clear professional recommendations to facilitate appropriate and optimized clinical utilization of such technologies.

Sleep-Disordered Breathing and Cardiac Arrhythmias in Adults: Mechanistic Insights and Clinical Implications: A Scientific Statement From the American Heart Association

Sleep-disordered breathing (SDB), characterized by specific underlying physiological mechanisms, comprises obstructive and central pathophysiology, affects nearly 1 billion individuals worldwide, and is associated with excessive cardiopulmonary morbidity. Strong evidence implicates SDB in cardiac arrhythmogenesis. Immediate consequences of SDB include autonomic nervous system fluctuations, recurrent hypoxia, alterations in carbon dioxide/acid-base status, disrupted sleep architecture, and accompanying increases in negative intrathoracic pressures directly affecting cardiac function. Day-night patterning and circadian biology of SDB-induced pathophysiological sequelae collectively influence the structural and electrophysiological cardiac substrate, thereby creating an ideal milieu for arrhythmogenic propensity. Cohort studies support strong associations of SDB and cardiac arrhythmia, with evidence that discrete respiratory events trigger atrial and ventricular arrhythmic events. Observational studies suggest that SDB treatment reduces atrial fibrillation recurrence after rhythm control interventions. However, high-level evidence from clinical trials that supports a role for SDB intervention on rhythm control is not available. The goals of this scientific statement are to increase knowledge and awareness of the existing science relating SDB to cardiac arrhythmias (atrial fibrillation, ventricular tachyarrhythmias, sudden cardiac death, and bradyarrhythmias), synthesizing data relevant for clinical practice and identifying current knowledge gaps, presenting best practice consensus statements, and prioritizing future scientific directions. Key opportunities identified that are specific to cardiac arrhythmia include optimizing SDB screening, characterizing SDB predictive metrics and underlying pathophysiology, elucidating sex-specific and background-related influences in SDB, assessing the role of mobile health innovations, and prioritizing the conduct of rigorous and adequately powered clinical trials.

Sleep apnea and atrial fibrillation: challenges in clinical and translational research

INTRODUCTION

Sleep-disordered breathing (SDB) is present in 21-74% of all patients with atrial fibrillation (AF). Treatment of SDB by positive airway pressure may help to prevent recurrence of AF after electrical cardioversion and help to improve AF ablation success rates in non-randomized studies.

AREAS COVERED

In this review, the current understanding of the atrial arrhythmogenic pathophysiology of SDB is summarized, and diagnostic and therapeutic challenges in AF patients are discussed. Current international recommendations are presented, and a comprehensive literature search is undertaken.

EXPERT OPINION

AF patients with SDB rarely report SDB-related symptoms such as daytime sleepiness. Therefore, systematic home sleep testing evaluation should be considered for all patients eligible for rhythm control strategy. A close interdisciplinary collaboration between the electrophysiologist/cardiologist, nurses and sleep-specialists are required for the management of SDB in AF patients. An arrhythmia-orientated assessment of SDB may better quantify SDB-related AF risk in an individual patient and may help to better guide targeted and personalized SDB treatment in AF patients as a component of rhythm and symptom control strategies. Finally, randomized controlled trials are needed to confirm the relationship between SDB and AF, and the benefits of routine testing and treatment of SDB in AF patients.

Sleep Apnoea and AF: Where Do We Stand? Practical Advice for Clinicians

AF is the most common sustained arrhythmia encountered in clinical practice. Among the largest contributing factors to the rapid increase in the incidence of AF are aging and obesity within the global population. Obstructive sleep apnoea (OSA) is a risk factor for AF that is clearly linked to obesity. Guidelines have advocated interrogation for clinical signs of OSA in all AF patients. The aim of this article is to provide practical advice for clinicians seeking to manage patients with AF and OSA. The authors discuss questionnaires to screen for OSA, various types of tests available for the diagnosis of OSA and data to assess the impact of treatment of OSA after various treatment options in AF patients. Finally, they outline the many areas that warrant further investigation in this patient population.

The value of screening questionnaires/scoring scales for obstructive sleep apnoea in patients with atrial fibrillation

BACKGROUND

Obstructive sleep apnoea (OSA) is an important modifiable risk factor for atrial fibrillation (AF) but is underdiagnosed in this population. Currently, polysomnography is the gold standard for diagnosing OSA, but is expensive and requires overnight examination. Alternatively, home sleep apnoea testing can be used as a diagnostic tool, but also requires a complete data review. Therefore, these OSA diagnostic modalities are not ideal screening methods. Several OSA screening tools exist, but their value in patients with AF remains unclear.

AIM

To test the performance of existing screening questionnaires/scales for clinically relevant OSA in patients with AF referred for diagnostic polysomnography.

METHODS

This prospective study compared the performance of seven screening tools (Epworth Sleepiness Scale, Berlin Questionnaire, Sleep Apnea Clinical Score, NoSAS, OSA50, STOP-Bang and MOODS) with polysomnography in the detection of clinically relevant OSA in consecutive patients with AF referred to two sleep clinics.

RESULTS

A total of 100 patients referred for polysomnography and known previous AF were included. Polysomnography indicated at least clinically relevant OSA (i.e., apnoea-hypopnoea index≥15 events/hour) in 69% of cases, and 33% had severe OSA (apnoea-hypopnoea index>30 events/hour). In screening for clinically relevant OSA, only the SACS and NoSAS scores had fair areas under the curve (0.704 and 0.712, respectively). None of the seven screening tools was performant enough (i.e., had a fair area under the curve>0.7) in the detection of severe OSA.

CONCLUSIONS

In this AF cohort referred for polysomnography, clinically relevant OSA was prevalent. None of the selected screening tools showed sufficient performance as a good discriminative screening tool for clinically relevant OSA in patients with AF. Given these findings, other screening modalities for OSA should be considered in the work-up of patients with AF.

Positionspapier „Schlafmedizin in der Kardiologie“, Update 2021

Es hat sich viel getan in der Welt der Schlafmedizin in der Kardiologie, weshalb eine vollwertige Überarbeitung des Positionspapiers „Schlafmedizin in der Kardiologie“ erforderlich wurde. In der aktuellen neuartigen Version finden sich nicht nur alle verfügbaren Studien, Literaturstellen und Updates zu Pathophysiologie, Diagnostik- und Therapieempfehlungen, sondern auch Ausblicke auf neue Entwicklungen und zukünftige Forschungserkenntnisse. Dieses überarbeitete Positionspapier gibt Empfehlungen für Diagnostik und Therapie von Patienten mit kardiovaskulären Erkrankungen mit schlafassoziierten Atmungsstörungen und erteilt darüber hinaus einen fundierten Überblick über verfügbare Therapien und Evidenzen, gibt aber ebenso Ratschläge wie mit Komorbiditäten umzugehen ist. Insbesondere enthält dieses überarbeitete Positionspapier aktualisierte Stellungnahmen zu schlafassoziierten Atmungsstörungen bei Patienten mit koronarer Herzerkrankung, Herzinsuffizienz, arterieller Hypertonie, aber auch für Patienten mit Vorhofflimmern. Darüber hinaus finden sich erstmals Empfehlungen zur Telemedizin als eigenes, neues Kapitel. Dieses Positionspapier bietet Kardiologen sowie Ärzten in der Behandlung von kardiovaskulären Patienten die Möglichkeit einer evidenzbasierten Behandlung der wachsend bedeutsamen und mit zunehmender Aufmerksamkeit behafteten Komorbidität schlafassoziierter Atmungsstörungen. Und nicht zuletzt besteht mit diesem neuen Positionspapier eine enge Verknüpfung mit dem neuen Curriculum Schlafmedizin der Deutschen Gesellschaft für Kardiologie, weshalb dieses Positionspapier eine Orientierung für die erworbenen Fähigkeiten des Curriculums im Umgang von kardiovaskulären Patienten mit schlafassoziierten Atmungsstörungen darstellt.

Sleep Disordered Breathing and Cardiovascular Disease: JACC State-of-the-Art Review

Sleep disordered breathing causes repetitive episodes of nocturnal hypoxemia, sympathetic nervous activation, and cortical arousal, often associated with excessive daytime sleepiness. Sleep disordered breathing is common in people with, or at risk of, cardiovascular (CV) disease including those who are obese or have hypertension, coronary disease, heart failure, or atrial fibrillation. Current therapy of obstructive sleep apnea includes weight loss (if obese), exercise, and positive airway pressure (PAP) therapy. This improves daytime sleepiness. Obstructive sleep apnea is associated with increased CV risk, but treatment with PAP in randomized trials has not been shown to improve CV outcome. Central sleep apnea (CSA) is not usually associated with daytime sleepiness in heart failure or atrial fibrillation and is a marker of increased CV risk, but PAP has been shown to be harmful in 1 randomized trial. The benefits of better phenotyping, targeting of higher-risk patients, and a more personalized approach to therapy are being explored in ongoing trials.

Clinical screening tools for obstructive sleep apnea in a population with atrial fibrillation: a diagnostic accuracy trial

STUDY OBJECTIVES

Although obstructive sleep apnea (OSA) is a known risk factor for atrial fibrillation (AF), there is a paucity of data around its diagnosis and management in patients with AF. The objectives of this study were to compare the diagnostic accuracy of commonly used OSA screening tools in an AF population, including a level 3 portable sleep study device, and to examine the epidemiology of OSA in a hospital cohort with AF.

METHODS

One hundred seven patients with AF recruited from 2 tertiary centers underwent a panel of OSA screening tools and in-laboratory polysomnography in randomized order.

RESULTS

Oxygen desaturation index derived from a level 3 portable sleep study device performed best for moderate to severe and severe OSA, with excellent diagnostic accuracy (area under the curve, 0.899; 95% confidence interval, 0.838-0.960 and area under the curve, 0.925; 95% confidence interval, 0.859-0.991, respectively). Sixty-seven patients (62.6%) were newly diagnosed with OSA (31.8% mild, 18.7% moderate, 12.1% severe).

CONCLUSIONS

Undiagnosed OSA is highly prevalent in a hospital AF cohort. However, it is characterized by a relative paucity of symptoms, markedly limiting the usefulness of history or screening questionnaires. This is the first study to find that a level 3 home sleep study device shows excellent diagnostic accuracy in patients with AF. This finding may inform AF management guidelines.

CLINICAL TRIAL REGISTRATION

Registry: Australian New Zealand Clinical Trials Registry; Name: The validity and reliability of a portable device for the diagnosis of Obstructive Sleep Apnoea in patients with Atrial Fibrillation; URL:https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=371024; Identifier: ACTRN12616001016426.

Sleep Apnea and Atrial Fibrillation

Obstructive sleep apnea (OSA) creates a complex and dynamic substrate for atrial fibrillation (AF), which is characterized by structural remodeling as a result of long-term OSA as well as transient and acute apnea-associated transient atrial electrophysiological changes. OSA is present in 21% to 74% of patients with AF, and nonrandomized studies suggest that treatment of OSA by continuous positive airway pressure may help to maintain sinus rhythm after electrical cardioversion and improve catheter ablation success rates. Management of OSA in patients with AF requires a close interdisciplinary collaboration between the electrophysiologist/cardiologist and sleep specialists.

Nocturnal hypoxemic burden during positive airway pressure treatment across different central sleep apnea etiologies

INTRODUCTION

Nocturnal hypoxemia is associated with increased cardiovascular mortality. Here, we assess whether positive airway pressure by adaptive servo-ventilation (ASV) reduces nocturnal hypoxemic burden in patients with primary central sleep apnea (primary CSA), or heart failure related central sleep apnea (CSA-HF) and treatment emergent central sleep apnea (TECSA).

METHODS

Overnight oximetry data from 328 consecutive patients who underwent ASV initiation between March 2010 and May 2018 were retrospectively analyzed. Patients were stratified into three groups: primary CSA (n = 14), CSA-HF (n = 31), TECSA (n = 129). Apnea hypopnea index (AHI) and time spent below 90% SpO₂ (T90) was measured. Additionally, T90 due to acute episodic desaturations (T90_Desaturation) and due to non-specific and non-cyclic drifts of SpO₂ (T90_Non-specific) were assessed.

RESULTS

ASV reduced the AHI below 15/h in all groups. ASV treatment significantly shortened T90 in all three etiologies to a similar extent. T90_Desaturation, but not T90_Non-specific, was reduced by ASV across all three patient groups. AHI was identified as an independent modulator for ΔT90_Desaturation upon ASV treatment (B (95% CI: -1.32 (-1.73; -0.91), p < 0.001), but not for ΔT90 or ΔT90_Non-specific. Body mass index was one independent predictor of T90.

CONCLUSIONS

Across different central sleep apnea etiologies, ASV reduced AHI, but nocturnal hypoxemic burden remained high due to a non-specific component of T90 not related to episodic desaturation. Whether adjunct risk factor management such as weight-loss can further reduce T90 warrants further study.

Screening for Obstructive Sleep Apnea in an Atrial Fibrillation Population: What's the Best Test?

Background

Among individuals with nonvalvular atrial fibrillation (AF), the prevalence of obstructive sleep apnea (OSA) can be as high as 85%. Continuous positive airway pressure treatment for moderate or severe OSA might improve AF outcomes and quality of life, so early identification of OSA might be of value. However, screening questionnaires for OSA are suboptimal because they are weighted toward tiredness and loud snoring, which might be absent in AF patients. NoSAS (Neck, Obesity, Snoring, Age, Sex) is a new OSA questionnaire that excludes these parameters. Acoustic pharyngometry (AP) is a potential novel screening technique that measures pharyngeal cross-sectional area, which is reduced in patients with OSA.

Methods

We prospectively compared the accuracy of the NoSAS, the STOP-BANG questionnaire (Snoring, Tiredness, Observed apnea, blood Pressure, Body mass index, Age, Neck circumference and Gender), and AP with home sleep apnea testing (HSAT) in consecutive patients with nonvalvular AF.

Results

Of 188 participants, 86% had OSA and 49% had moderate or severe OSA. Mean Epworth Sleepiness Scale scores were low; 5.9 (SD, 3.9), indicating that most participants were not sleepy. Receiver operating characteristic curves for comparisons of screening tests with HSAT showed suboptimal accuracy. For moderate plus severe and severe only groups respectively, the area under the curve was 0.50 (95% confidence interval [CI], 0.42-0.58) and 0.42 (95% CI, 0.34-0.52) for AP, 0.65 (95% CI, 0.58-0.73) and 0.63 (95% CI, 0.52-0.74) for the STOP-BANG questionnaire, and 0.68 (95% CI, 0.60-0.75) and 0.69 (95% CI, 0.59-0.80) for the NoSAS.

Conclusions

AP and NoSAS are not sufficiently accurate for screening AF patients for OSA. Because of the high rates of OSA in this cohort, the potential benefits of OSA treatment, and the suboptimal accuracy of current screening questionnaires, cardiologists should consider HSAT for AF patients.

On-demand mobile health infrastructures to allow comprehensive remote atrial fibrillation and risk factor management through teleconsultation

BACKGROUND

Although novel teleconsultation solutions can deliver remote situations that are relatively similar to face-to-face interaction, remote assessment of heart rate and rhythm as well as risk factors remains challenging in patients with atrial fibrillation (AF).

HYPOTHESIS

Mobile health (mHealth) solutions can support remote AF management.

METHODS

Herein, we discuss available mHealth tools and strategies on how to incorporate the remote assessment of heart rate, rhythm and risk factors to allow comprehensive AF management through teleconsultation.

RESULTS

Particularly, in the light of the coronavirus disease 2019 (COVID-19) pandemic, there is decreased capacity to see patients in the outpatient clinic and mHealth has become an important component of many AF outpatient clinics. Several validated mHealth solutions are available for remote heart rate and rhythm monitoring as well as for risk factor assessment. mHealth technologies can be used for (semi-)continuous longitudinal monitoring or for short-term on-demand monitoring, dependent on the respective requirements and clinical scenarios. As a possible solution to improve remote AF care through teleconsultation, we introduce the on-demand TeleCheck-AF mHealth approach that allows remote app-based assessment of heart rate and rhythm around teleconsultations, which has been developed and implemented during the COVID-19 pandemic in Europe.

CONCLUSION

Large scale international mHealth projects, such as TeleCheck-AF, will provide insight into the additional value and potential limitations of mHealth strategies to remotely manage AF patients. Such mHealth infrastructures may be well suited within an integrated AF-clinic, which may require redesign of practice and reform of health care systems.

Nocturnal oxygen desaturation in the late third trimester of uncomplicated pregnancy for prediction of late-onset gestational hypertension

AIM

This study aimed to determine whether 1-night screening of oxygen desaturation in women with uncomplicated pregnancy about 1 month before the due date is useful to predict late-onset gestational hypertension (GH) after 37 weeks of gestation.

METHODS

We recruited 102 women with uncomplicated pregnancy between 34 and 36 weeks of gestation. These women then completed the Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale, and Berlin Questionnaire for obstructive sleep apnea, and recorded their oxygen saturation (SpO₂ ) and physical acceleration profiles during nocturnal sleep for 1 night at home using a portable pulse oximeter and actigraph, respectively. Thereafter, their blood pressure was monitored weekly until delivery.

RESULTS

Pulse oximetry data between 34 and 36 weeks of gestation revealed that three women had an oxygen desaturation index (ODI) ≥5.0 and seven had a minimum SpO₂ < 90%. During follow-up until delivery, two women with an ODI ≥5.0 and a minimum SaO₂ <90% developed GH at 37 weeks of gestation. Among clinical measures at recruitment, body mass index (BMI) and pulse oximetry measures appeared available for the prediction of GH. The positive predictive values (95% confidence intervals) of the criteria using these measures were 0.67 (0.26-0.67) for ODI ≥5.0, 0.29 (0.10-0.35) for minimum SpO₂ <90%, and 0.07 (0.02-0.07) for BMI ≥25.0.

CONCLUSION

For the prediction of late-onset GH after 37 weeks of gestation, pulse oximetry measures about 1 month before the due date are particularly useful because of their high positive predictive values.

Low Prognostic Value of Novel Nocturnal Metrics in Patients With OSA and High Cardiovascular Event Risk: Post Hoc Analyses of the SAVE Study

BACKGROUND

Traditional methods for the quantification of OSA severity may not encapsulate potential relationships between hypoxemia in OSA and cardiovascular risk.

RESEARCH QUESTION

Do novel nocturnal oxygen saturation (Spo₂) metrics have prognostic value in patients with OSA and high cardiovascular event risk?

STUDY DESIGN AND METHODS

We conducted post hoc analyses of the Sleep Apnea Cardiovascular Endpoints (SAVE) trial. In 2687 individuals, Cox proportional hazards models that were stratified for treatment allocation were used to determine the associations between clinical characteristics, pulse oximetry-derived metrics that were designed to quantify sustained and episodic features of hypoxemia, and cardiovascular outcomes. Metrics included oxygen desaturation index, time <90% Spo₂, average Spo₂ for the entire recording (mean Spo₂), average Spo₂ during desaturation events (desaturation Spo₂), average baseline Spo₂ interpolated across episodic desaturation events (baseline Spo₂), episodic desaturation event duration and desaturation/resaturation-time ratio, and mean and SD of pulse rate.

RESULTS

Neither apnea-hypopnea index, oxygen desaturation index, nor any of the novel Spo₂ metrics were associated with the primary SAVE composite cardiovascular outcome. Mean and baseline Spo₂ were associated with heart failure (hazard ratio [HR], 0.81; 95% CI, 0.69-0.95; P = .009; and HR, 0.78; 95% CI, 0.67-0.90; P = .001, respectively) and myocardial infarction (HR, 0.86; 95% CI, 0.77-0.95; P = .003; and HR, 0.81; 95% CI, 0.73-0.90; P < .001, respectively). Desaturation duration and desaturation/resaturation time ratio, with established risk factors, predicted future heart failure (area under the curve, 0.86; 95% CI, 0.79-0.93).

INTERPRETATION

Apnea-hypopnea index and oxygen desaturation index were not associated with cardiovascular outcomes. In contrast, the pattern of oxygen desaturation was associated with heart failure and myocardial infarction. However, concomitant risk factors remained the predominant determinants for secondary cardiovascular events and thus deserve the most intensive management.

The uses of overnight pulse oximetry

Overnight pulse oximetry (OPO) has proven to be an effective and beneficial technique to determine the cardiorespiratory status of patients in both the inpatient and outpatient settings. It is a cheap, safe, reliable, simple, and accurate method of patient monitoring as compared to the expensive and labor-intensive method of multichannel polysomnography for detecting sleep-disordered breathing. It provides accurate information about patient's oxygenation status and also helps in monitoring the response to continuous positive airway pressure and in the surgical treatment of obstructive sleep apnea (OSA). Nocturnal hypoxemia portends a poor prognosis in patients of chronic obstructive pulmonary disease (COPD), interstitial lung disease (ILD), and neuromuscular diseases. OPO can help its early detection and management.

Nightly sleep apnea severity in patients with atrial fibrillation: Potential applications of long-term sleep apnea monitoring

In patients with atrial fibrillation (AF), the prevalence of moderate-to-severe sleep-disordered breathing (SDB) ranges between 21% and 72% and observational studies have demonstrated that SDB reduces the efficacy of rhythm control strategies, while treatment with continuous positive airway pressure lowers the rate of AF recurrence. Currently, the number of apneas and hypopneas per hour (apnea-hypopnea-index, AHI) determined during a single overnight sleep study is clinically used to assess the severity of SDB. However, recent studies suggest that SDB-severity in an individual patient is not stable over time but exhibits a considerable night-to-night variability which cannot be detected by only one overnight sleep assessment. Nightly SDB-severity assessment rather than the single-night diagnosis by one overnight sleep study may better reflect the exposure to SDB-related factors and yield a superior metric to determine SDB-severity in the management of AF. In this review we discuss mechanisms of night-to-night SDB variability, arrhythmogenic consequences of night-to-night SDB variability, strategies for longitudinal assessment of nightly SDB-severity and clinical implications for screening and management of SDB in AF patients.