Sleep-disordered breathing in patients with cardiovascular diseases cannot be detected by ESS, STOP-BANG, and Berlin questionnaires

Utility of cardiac implantable electronic device algorithm for detecting severe sleep-disordered breathing in cardiomyopathy

Background

Half of patients with heart failure are estimated to have sleep-disordered breathing (SDB). However, many are undiagnosed as they do not report typical symptoms. This study aims to evaluate the implantable cardiac defibrillator (ICD) sleep-disordered breathing algorithm in a cohort of multi-racial Asian patients for detection of SDB against polysomnography (PSG).

Methods

In this prospective pilot study, participants who fulfill the American College of Cardiology (ACC) indication for ICD were recruited. The ICD algorithm uses transthoracic impedance sensing to calculate respiratory disturbance index (RDI).

Results

Twenty-four patients were enrolled between August 2020 and December 2021. All patients underwent PSG exams and were followed up for up to 12 months. Eighteen participants completed the PSG study as of August 23, 2022. Severe SDB (defined as PSG-AHI ≥30 episodes/h) was diagnosed in 66.7% of the patients. No significant direct linear correlation was found between the PSG-AHI measurements and the RDI measurements (adjusted r 2 = .224, r = .473, p = .027). Applying a binary threshold cut-off RDI value of 32 episodes/h for the detection of severe SDB yielded a sensitivity of 91.7% and specificity of 16.7%.

Conclusions

Transthoracic impedance sensing with an advanced inbuilt algorithm may be helpful as a screening test in detecting severe SDB in patients with heart failure and cardiomyopathy, potentially by applying a binary threshold cut-off value. This is the first study known to validate the algorithm in an exclusively multi-ethnic Asian population with heart failure.

Sleep apnea after stroke: A novel target

Sleep apnea is an independent risk factor for cerebrovascular diseases. Its prevalence in stroke survivors is high and the disorder negatively affects patients' outcomes. Despite the importance of sleep apnea assessment is highlighted also in the current guidelines, a high proportion of patients remain undiagnosed and lose the potential benefit of positive airway pressure treatment. The current paper describes links between sleep apnea and stroke. It focuses on the challenges of the diagnostic and therapeutical process and provides a brief insight into ongoing trials that could help to identify appropriate diagnostic and therapeutic approaches, their timing, and the patient population for whom treatment could be most beneficial.

Measurement of peripheral arterial tone to detect sleep-disordered breathing in patients with heart failure

PURPOSE

Sleep-disordered breathing is highly prevalent in patients with heart failure and is related to increased mortality and morbidity. The gold standard for sleep diagnostic is polysomnography in a sleep laboratory. Measurement of peripheral arterial tone with a wrist-worn diagnostic device is a promising method to detect sleep-disordered breathing without major technical effort.

METHODS

We prospectively enrolled patients with heart failure with reduced ejection fraction for measurement of the peripheral arterial tone and polysomnography simultaneously during one night in the sleep laboratory. Raw data of polysomnography was analyzed blindly by sleep core lab personnel and compared with automatic algorithm-based sleep results of measurement of the peripheral arterial tone.

RESULTS

A total of 25 patients provided comparable sleep results. All patients had sleep-disordered breathing and were identified by measurement of the peripheral arterial tone. The comparison of apnea-hypopnea index between peripheral arterial tone 38.8 ± 17.4/h and polysomnography 44.5 ± 17.9/h revealed a bias of - 5.7 ± 9.8/h with limits of agreement of ± 19.2/h in Bland-Altman analysis but showed high and significant Pearson correlation (r = 0.848, p < 0.001).

CONCLUSION

The findings suggest that measurement of the peripheral arterial tone may be useful to identify sleep-disordered breathing in patients with heart failure with reduced ejection fraction.

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.

Comparison of the value of the STOP-BANG questionnaire with oxygen desaturation index in screening obstructive sleep apnea in Germany

PURPOSE

Despite polysomnography being the gold standard method of diagnosing obstructive sleep apnea (OSA), it is time-consuming and has long waiting lists. Alternative methods including questionnaires and portable sleep devices have been developed to increase the speed of diagnosis. However, most questionnaires such as the STOP-BANG questionnaire (SBQ) are limited due to low specificity. This study evaluated the value of SBQ to screen for OSA and compared it with the oxygen desaturation index (ODI) and their combination.

METHODS

This retrospective study included patients who completed the SBQ and underwent a night at the sleep lab or home sleep testing. The ODI was extracted from these sleep study reports. The combination of SBQ with ODI and their individual scores were compared with apnea-hypopnea index (AHI) in terms of their accuracy in diagnosing OSA. Sensitivity, specificity, and area under the curve (AUC) for different severities of OSA were calculated and compared.

RESULTS

Among 132 patients, SBQ showed a sensitivity of 0.9 and a specificity of 0.3 to screen for OSA. As the severity of OSA increased, the sensitivity increased whilst specificity decreased for both measurements. ODI achieved an increased specificity of 0.8 and could correctly diagnose OSA 86% of the time which was better than SBQ's 60%. For all severities of OSA, ODI alone displayed a larger AUC than SBQ and similar AUC to their combination.

CONCLUSION

ODI produced a higher specificity and AUC than SBQ. Furthermore, ODI combined with SBQ failed to increase diagnostic value. Therefore, ODI may be the preferred way to initially screen patients for OSA as an easy-to-use alternative compared to SBQ.

The Usefulness of Questionnaires in Assessing the Risk of Obstructive Sleep Apnea in Patients in the Managed Care after Acute Myocardial Infarction Program-The Results of a Cross-Sectional Study

Obstructive sleep apnea (OSA) worsens prognosis after myocardial infarction (MI) but often remains undiagnosed. The study aimed to evaluate the usefulness of questionnaires in assessing the risk of OSA in patients participating in managed care after an acute myocardial infarction program. Study group: 438 patients (349 (79.7%) men) aged 59.92 ± 10.92, hospitalized in the day treatment cardiac rehabilitation department 7-28 days after MI. OSA risk assessment: A 4-variable screening tool (4-V), STOP-BANG questionnaire, Epworth sleepiness scale (ESS), and adjusted neck circumference (ANC). The home sleep apnea testing (HSAT) was performed on 275 participants. Based on four scales, a high risk of OSA was found in 283 (64.6%) responders, including 248 (56.6%) based on STOP-BANG, 163 (37.5%) based on ANC, 115 (26.3%) based on 4-V, and 45 (10.3%) based on ESS. OSA was confirmed in 186 (68.0%) participants: mild in 85 (30.9%), moderate in 53 (19.3%), and severe in 48 (17.5%). The questionnaires' sensitivity and specificity in predicting moderate-to-severe OSA were: for STOP-BANG-79.21% (95% confidence interval; CI 70.0-86.6) and 35.67% (95% CI 28.2-43.7); ANC-61.39% (95% CI 51.2-70.9) and 61.15% (95% CI 53.1-68.8); 4-V-45.54% (95% CI 35.6-55.8) and 68.79% (95% CI 60.9-75.9); ESS-16.83% (95% CI 10.1-25.6) and 87.90% (95% CI 81.7-92.6). OSA is common in post-MI patients. The ANC most accurately estimates the risk of OSA eligible for positive airway pressure therapy. The sensitivity of the ESS in the post-MI population is insufficient and limits this scale's usefulness in risk assessment and qualification for treatment.

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.

Prevalence, clinical characteristics, and predictors of sleep disordered breathing in hospitalized heart failure patients

BACKGROUND

Heart failure (HF) is often comorbid with sleep disordered breathing (SDB). This prospective study investigated the prevalence, clinical characteristics, and predictors of SDB in hospitalized HF patients.

METHODS

Sleep studies were performed on hospitalized HF patients from January 2015 to February 2019. SDB was categorized as no/mild SDB, obstructive sleep apnea (OSA), and central sleep apnea (CSA).

RESULTS

The study included 1069 hospitalized HF patients. The prevalence rates of OSA and CSA were 16.6% and 36.9%, respectively. Patients with OSA or CSA were more likely to be male and have a higher body mass index (BMI) and more comorbidities. Multivariate logistic regression analysis showed that male sex (odds ratio [OR] = 1.803, 95% confidence interval  [CI] = 1.099-2.958), BMI (per 5 kg/m² increase: OR = 2.270, 95% CI = 1.852-2.783), hypertension (OR = 2.719, 95% CI = 1.817-4.070), diabetes (OR = 1.477, 95% CI = 1.020-2.139), and left ventricular ejection fraction (LVEF) (per 5% increase, OR = 1.126, 95% CI = 1.053-1.204) were independent predictors of OSA. Male sex (OR = 1.699, 95% CI = 1.085-1.271), age (per 10 years, OR = 1.235, 95% CI = 1.118-1.363), heart rate (per 10 bpm, OR = 1.174, 95% CI = 1.099-2.958), LVEF (per 5% increase, OR = 0.882, 95% CI = 0.835-0.932), NT-proBNP (lnNT-proBNP, OR = 1.234, 95% CI = 1.089-1.398) and hypocapnia (OR = 1.455, 95% CI = 1.105-1.915) were independent predictors of CSA. The areas under the receiver operating characteristic curves were 0.794 (95% CI = 0.758-0.830) and 0.673 (95% CI = 0.640-0.706), respectively.

CONCLUSIONS

More than half of hospitalized HF patients had OSA or CSA, and CSA was the predominant type. OSA and CSA predictors differ. The clinical characteristics of HF patients can help make preliminary predictions for SDB patients.

Impact of undiagnosed obstructive sleep apnea on atrial fibrillation recurrence following catheter ablation (OSA-AF study)

Background

Sleep-disordered breathing (SDB) may hamper the outcome of catheter ablation of atrial fibrillation (AF). However, SDB is underdiagnosed in clinical practice and the relevancy of undiagnosed SDB on the outcome of catheter ablation is unclear.

Objective

To evaluate if undiagnosed SDB has an impact on AF recurrence after catheter ablation.

Methods

In this single-center cohort study we enrolled patients who had a catheter ablation of AF 12 to 18 months prior to enrolment. Patients with diagnosed SDB at the time of catheter ablation were excluded. Enrolled patients underwent screening using WatchPAT (WP). SDB was defined as an apnea-hypopnea index (AHI) ≥ 15.

Results

A total of 164 patients were screened for eligibility. After exclusion of patients with previously diagnosed SDB (n = 30), 104 of 134 eligible patients were enrolled and underwent SDB screening. The median AHI was 11.5 (interquartile range 6.8-21.9) and 39 patients (38%) had SDB which was undiagnosed during the first year after ablation. AF recurrence in the first year after catheter ablation occurred in 40 patients (38%). The risk of AF recurrence was higher in the group with undiagnosed SDB in comparison to those without SDB (51% versus 31%, P = 0.04). Interestingly, the prevalence of AF recurrence was similar between patients with previously diagnosed and undiagnosed SDB (51% versus 50%, P = 0.92).

Conclusion

A significant proportion of patients undergoing catheter ablation of AF have undiagnosed SDB which is associated with a twofold higher risk of AF recurrence. SDB screening may improve patient counselling regarding the efficacy of catheter ablation.

Sleep-Disordered Breathing in Hospitalized Patients: A Game Changer?

Sleep disorders, including sleep apnea, have become a significant health issue in the United States. It is estimated that 22 million Americans have sleep apnea, with 80% of cases of moderate and severe OSA going undiagnosed. This number continues to increase with the obesity epidemic. Sleep-disordered breathing (SDB) is associated with multiple cardiopulmonary diseases and has been shown to affect disease outcomes adversely. Hospitalized patients have a disproportionately high prevalence of cardiovascular and respiratory diseases. Screening for SDB in hospitalized patients provides an opportunity to identify the disease in individuals whose disease otherwise may go unrecognized. Data suggest that identification of SDB in hospitalized individuals may have a positive impact on a patient's course after hospitalization. Unfortunately, sleep medicine currently remains an ambulatory practice. Hospital sleep medicine addresses this separation. Herein, we discuss our experience and the future potential of hospital sleep medicine programs.

Prognostic Impact of Sleep Patterns and Related-Drugs in Patients with Heart Failure

Sleep disturbances are frequent among patients with heart failure (HF). We hypothesized that self-reported sleep disturbances are associated with a poor prognosis in patients with HF. A longitudinal study of 119 patients with HF was carried out to assess the association between sleep disturbances and the occurrence of major cardiovascular events (MACE). All patients with HF completed self-administered questionnaires on sleepiness, fatigue, insomnia, quality of sleep, sleep patterns, anxiety and depressive symptoms, and central nervous system (CNS) drugs intake. Patients were followed for a median of 888 days. Cox models were used to estimate the risk of MACE associated with baseline sleep characteristics. After adjustment for age, the risk of a future MACE increased with CNS drugs intake, sleep quality and insomnia scores as well with increased sleep latency, decreased sleep efficiency and total sleep time. However, after adjustment for left ventricular ejection fraction and hypercholesterolemia the HR failed to be significant except for CNS drugs and total sleep time. CNS drugs intake and decreased total sleep time were independently associated with an increased risk of MACE in patients with HF. Routine assessment of self-reported sleep disturbances should be considered to prevent the natural progression of HF.

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.

Excessive daytime sleepiness, morning tiredness and major adverse cardiovascular events in patients with chronic coronary syndrome

BACKGROUND

Sleep-related breathing disorders (SRBDs), particularly obstructive sleep apnoea, are associated with increased cardiovascular (CV) risk. However, it is not known whether individual questions used for SRBD screening are associated with major adverse CV events (MACE) and death specifically in patients with chronic coronary syndrome (CCS).

METHODS

Symptoms associated with SRBD were assessed by a baseline questionnaire in 15,640 patients with CCS on optimal secondary preventive therapy in the STABILITY trial. The patients reported the frequency (never/rarely, sometimes, often and always) of: 1) loud snoring; 2) more than one awakening/night; 3) morning tiredness (MT); 4) excessive daytime sleepiness (EDS); or 5) gasping, choking or apnoea when asleep. In adjusted Cox regression models, associations between the frequency of SRBD symptoms and CV outcomes were assessed with never/rarely as reference.

RESULTS

During a median follow-up time of 3.7 years, 1,588 MACE events (541 CV deaths, 749 nonfatal myocardial infarctions [MI] and 298 nonfatal strokes) occurred. EDS was associated (hazard ratio [HR], 95% confidence interval [CI]) with increased risk of MACE (sometimes 1.14 [1.01-1.29], often 1.19 [1.01-1.40] and always 1.43 [1.15-1.78]), MI (always 1.61 [1.17-2.20]) and all-cause death (often 1.26 [1.05-1.52] and always 1.71 [1.35-2.15]). MT was associated with higher risk of MACE (often 1.23 [1.04-1.45] and always 1.46 [1.18-1.81]), MI (always 1.61 [1.22-2.14]) and all-cause death (always 1.54 [1.20-1.98]). The other SRBD-related questions were not consistently associated with worse outcomes.

CONCLUSIONS

In patients with CCS, gradually higher levels of EDS and MT were independently associated with increased risk of MACE, including mortality.

An Update on Obstructive Sleep Apnea for Atherosclerosis: Mechanism, Diagnosis, and Treatment

The occurrence and development of atherosclerosis could be influenced by intermittent hypoxia. Obstructive sleep apnea (OSA), characterized by intermittent hypoxia, is world-wide prevalence with increasing morbidity and mortality rates. Researches remain focused on the study of its mechanism and improvement of diagnosis and treatment. However, the underlying mechanism is complex, and the best practice for OSA diagnosis and treatment considering atherosclerosis and related cardiovascular diseases is still debatable. In this review, we provided an update on research in OSA in the last 5 years with regard to atherosclerosis. The processes of inflammation, oxidative stress, autonomic nervous system activation, vascular dysfunction, platelet activation, metabolite dysfunction, small molecule RNA regulation, and the cardioprotective occurrence was discussed. Additionally, improved diagnosis such as, the utilized of portable device, and treatment especially with inconsistent results in continuous positive airway pressure and mandibular advancement devices were illustrated in detail. Therefore, further fundamental and clinical research should be carried out for a better understanding the deep interaction between OSA and atherosclerosis, as well as the suggestion of newer diagnostic and treatment options.

The Berlin Questionnaire in pregnancy predominantly identifies obesity

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) is common in pregnant women and is a risk factor for poor perinatal outcomes. The Berlin Questionnaire (BQ) is a validated OSA screening tool that is often used in pregnancy. However, its poor performance in this population is likely attributed to the scoring paradigm that primarily identifies obesity. Moreover, the associations between the BQ and pregnancy outcomes are often those same outcomes that are obesity-related. Therefore, this study examined associations between each of the three BQ domains, independently and jointly, in relation to gestational diabetes (GDM) and hypertensive disorders of pregnancy (HDP).

METHODS

Pregnant third-trimester women were recruited from a tertiary medical center and completed the BQ, which includes three independent domains: snoring; sleepiness; and obesity/high blood pressure. Medical records were accessed for diagnoses of GDM and HDP.

RESULTS

Of the 1,588 pregnant women, 44% had a positive BQ score. Women with a positive score for domains of snoring exclusively, sleepiness exclusively, or their combination did not have an increased risk for GDM or HDP. However, women without snoring or sleepiness, but with a positive score on the BMI/BP domain had increased odds of GDM (OR 2.0, 95%CI 1.3-3.3) and HDP (OR 2.9, 95%CI 1.6-5.5). Further, any positive score in domain combinations that included BMI/BP had increased odds of GDM and HDP compared with negative scores in all domains. In addition, presence of obesity without hypertension, snoring, or sleepiness, the odds of GDM and HDP were similarly increased.

CONCLUSIONS

The poor performance of the BQ in screening for OSA risk, may be attributed to its predominant reliance on identification of obesity.

Validation of the STOP-Bang questionnaire as a screening tool for obstructive sleep apnoea in patients with cardiovascular risk factors: a systematic review and meta-analysis

Introduction

Obstructive sleep apnoea (OSA) is highly prevalent in patients with cardiovascular risk factors and is associated with increased morbidity and mortality. This review presents the predictive parameters of the STOP-Bang questionnaire as a screening tool for OSA in this population.

Methods

A search of databases was performed. The inclusion criteria were: (1) use of the STOP-Bang questionnaire to screen for OSA in adults (>18 years) with cardiovascular risk factors; (2) polysomnography or home sleep apnoea testing performed as a reference standard; (3) OSA defined by either Apnoea–Hypopnoea Index (AHI) or Respiratory Disturbance Index; and (4) data on predictive parameters of the STOP-Bang questionnaire. A random-effects model was used to obtain pooled predictive parameters of the STOP-Bang questionnaire.

Results

The literature search resulted in 3888 articles, of which 9 papers met the inclusion criteria, involving 1894 patients. The average age of the included patients was 58±13 years with body mass index (BMI) of 30±6 kg/m², and 64% were male. The STOP-Bang questionnaire has a sensitivity of 89.1%, 90.7% and 93.9% to screen for all (AHI ≥5), moderate-to-severe (AHI ≥15) and severe (AHI≥30) OSA, respectively. The specificity was 32.3%, 22.5% and 18.3% and the area under the curve (AUC) was 0.86, 0.65 and 0.52 for all, moderate-to-severe and severe OSA, respectively.

Conclusion

The STOP-Bang questionnaire is an effective tool to screen for OSA (AHI≥5) with AUC of 0.86 in patients with cardiovascular risk factors.

Diagnostic accuracy and suitability of instruments that screen for obstructive sleep apnoea, insomnia and sleep quality in cardiac patients: a meta-analysis

BACKGROUND

A number of clinical guidelines recommend that all cardiac rehabilitation patients should be screened for potential sleep disorders with a validated screening instrument. There is currently no consensus on what specific tools should be used.

OBJECTIVE

To identify tools that are practical to use in the clinical environment and have high diagnostic accuracy.

METHODS

We systematically searched online databases to identify patient reported outcome instruments that have been used in published research studies to assess the likelihood of obstructive sleep apnoea (OSA) in cardiac patients. In studies that provided diagnostic data, these data were extracted and verified via an evidence-based diagnostic calculator. Where sufficient numbers of studies were available, a meta-analysis was conducted to determine pooled estimates of specificity, sensitivity and diagnostic odds ratios. Selected papers were qualitatively assessed using the Standards for Reporting Diagnostic accuracy studies (STARD).

RESULTS

Of the 21 instruments identified, six detected likelihood of OSA, two assessed daytime sleepiness, five assessed insomnia and eight examined sleep quality. A meta-analysis of 14 studies that assessed diagnostic accuracy of moderate OSA, revealed moderate sensitivity for the Berlin Questionnaire, Sens = 0.49 (95% CI 0.45-0.52) and good sensitivity for the Stop-BANG, Sens = 0.93 (95% CI 0.87-0.96) but poor specificity at standard cut-off criteria.

CONCLUSION

There are promising practical tools available to screen patients with OSA and other sleep disorders in cardiac rehabilitation settings, but specificity could be improved. Additional assessment of sleep quality may enhance prognostic ability with both OSA and insomnia screening.

Sleep-disordered breathing after lung transplantation: An observational cohort study

Data concerning sleep-disordered breathing (SDB) after lung transplantation (LTX) are scarce. This study aims to analyze prevalence, associated factors, and impact on survival of moderate to severe SDB in a large cohort of consecutive LTX patients (n = 219). Patients underwent a diagnostic polysomnography 1 year after LTX. Moderate to severe SDB was present in 57.5% of patients, with the highest prevalence in chronic obstructive pulmonary disease/emphysema (71.1%) and pulmonary fibrosis (65.1%). SDB patients were older, mostly male, and had higher body mass index and neck circumference. Nocturnal diastolic and 24-hour blood pressures were higher in SDB patients. In 45 patients, polysomnography was also performed pre-LTX. Compared to pre-LTX, mean apnea/hypopnea index (AHI) increased significantly after LTX. A significant correlation was seen between lung function parameters and AHI, suggesting a role of decreased caudal traction on the pharynx. Presence of SDB had no impact on mortality or prevalence of chronic lung allograft dysfunction. However, survival was better in continuous positive airway pressure (CPAP) compliant SDB patients compared to SDB patients without CPAP treatment. These findings may be pertinent for systematic screening of SDB after LTX.

Obstructive Sleep Apnea Risk Is Associated with Cognitive Impairment after Controlling for Mild Traumatic Brain Injury History: A Chronic Effects of Neurotrauma Consortium Study

The contribution of sleep disturbance to persistent cognitive symptoms following a mild traumatic brain injury (mTBI) remains unclear. Obstructive sleep apnea (OSA) is very common, yet its relationship between risk factors for developing OSA and cognitive performance in those with history of mTBI has not been investigated. The current study examined OSA risk levels and its association with cognitive performance in 391 combat-exposed, post-911 veterans and service members (median age = 37 years) enrolled in the Chronic Effects of Neurotrauma Consortium (CENC) prospective multi-center study. Participants included those with and without mTBI (n = 326 and 65, respectively). When using clinical cut-offs, those with history of mTBI were more likely to be categorized as high risk for OSA (mTBI positive = 65% vs. mTBI negative = 51%). After adjustment for TBI status and demographic variables, increased OSA risk was significantly associated with worse performance on measures of complex processing speed and executive functioning (Wechsler Adult Intelligence Scale Fourth Edition Coding, Trail Making Test, part B) and greater symptom burden (Neurobehavioral Symptom Inventory). Thus, OSA, a modifiable behavioral health factor, likely contributes to cognitive performance following mTBI. Accordingly, OSA serves as a potential point of intervention to improve clinical and cognitive outcomes after injury.

Sleep apnea prediction in acute ischemic stroke (SLAPS score): a derivation study

BACKGROUND

Despite its high prevalence and negative impact, sleep-disordered breathing (SDB) remain commonly underdiagnosed and undertreated in stroke subjects. Multiple stroke comorbidities and risk factors, including obesity, hypertension, diabetes mellitus, ischemic heart disease, atrial fibrillation, and heart failure (H.F.) have been associated with SDB. This study aimed to examine associations of clinical and demographic characteristics with moderate-to-severe SDB (msSDB) in stroke patients and to develop a predictive score.

METHODS

Consecutive patients with ischemic stroke were enrolled in an open, prospective study. SDB was assessed using standard polysomnography. Clinical and demographic characteristics, as well as findings from echocardiography, entered the analysis. Multivariate logistic regression models were used to examine the associations with msSDB. Based on the results, an original score to predict msSDB was proposed and tested.

RESULTS

120 patients with acute ischemic stroke (mean age: 64.0 ± 12.2 years, median NIHSS: 4) were included. Body-mass index (BMI), wake-up stroke onset (WUS), and diastolic dysfunction were independently associated with msSDB. A score allocating 1 point for BMI≥25 kg/m² and <30 kg/m², 2 points for BMI≥30 kg/m², 1 point for WUS and 1 point for diastolic dysfunction resulted in an area under the curve of 0.81 (95% CI 0.71-0.90, p<0.001), sensitivity 82.9%, specificity 71.9% to identify stroke patients with msSDB.

CONCLUSIONS

BMI, WUS, and diastolic dysfunction were associated with msSDB. A simple score might help to identify acute stroke patients with msSDB, who are usual candidates for positive airway pressure therapy.

Opiate Use and Escalation of Care in Hospitalized Adults with Acute Heart Failure and Sleep-disordered Breathing (OpiatesHF Study)

Rationale: Sleep-disordered breathing (SDB) is highly prevalent in adults hospitalized with acute heart failure. Data are limited on the implications of inadvertent opiate use in this population.Objectives: To determine the prevalence and impact of in-hospital opiate use in adults hospitalized for acute heart failure.Methods: From a prospective sleep registry, we selected a sequential group of adult participants who were admitted to the hospital for acute heart failure and received a portable sleep study (PSS) after screening for SDB using the STOP-BANG questionnaire. A retrospective review of charts was performed to assess use of opiates, need for escalation of care (defined as transfer to the intensive care unit [ICU]), 30-day readmission, and length of stay. A logistic regression model was used to calculate propensity scores for each participant with a screening apnea-hypopnea index (AHI) greater than or equal to 10/h. Study endpoints, including escalation of care to the ICU and 30-day hospital readmission, were compared using a χ² test with stabilized inverse probability-weighted propensity scores to control for potential confounding variables.Results: A total of 301 consecutive adults admitted with acute heart failure between November 2016 and October 2017 underwent PSS after SDB screening. Overall, 125 of 301 (41.5%) received opiates in the hospital, and 149 (49.5%) patients had an AHI greater than or equal to 10/h by PSS (high risk of SDB). In this high-risk group, 47 of 149 (32%) received opiates. Among those with an AHI greater than or equal to 10/h, escalation of care occurred in 12 of 47 (26%) of those who received opiates versus 4 of 102 (4%) of those who did not (P < 0.001; weighted estimate of treatment difference, 23.5%; 95% confidence interval [CI], 9.9 to 37.2). Similarly, readmission within 30 days occurred in 7 of 47 (15%) of those who received opiates versus 9 of 102 (9%) of those who did not (P = 0.14; weighted estimate of treatment difference, 8.3%; 95% CI, -4.0 to 20.6). Mean length of stay (days) did not differ between groups (P = 0.61; weighted estimate of treatment difference, -0.3 d; 95% CI, -1.4 to 0.8).Conclusions: In adults admitted with acute heart failure and found to be at high risk of SDB, opiate use in the hospital was highly prevalent and was associated with a greater likelihood of escalation of care.

Association between excessive daytime sleepiness and measures of supraventricular arrhythmia burden: evidence from the Atherosclerosis Risk in Communities (ARIC) study

PURPOSE

Excessive daytime sleepiness is a common sleep complaint among older adults. Assessment of excessive daytime sleepiness is used to screen for obstructive sleep apnea, which may be linked to atrial fibrillation (AF) and other sustained arrhythmias. Using data from the Atherosclerosis Risk in Communities (ARIC) Study cohort, we examined the association of excessive daytime sleepiness with measures of arrhythmia burden derived from a continuous ECG recording device in a community-based sample of older adults.

METHODS

Participating older adults (N = 2306, mean age: 78.9 ± 4.5 years, 57.8% female) wore a Zio® XT Patch for 14 days. Excessive daytime sleepiness was assessed with the Epworth Sleepiness Scale. Measures of AF and supraventricular arrhythmia burden were derived from the Zio® XT Patch. Multiple adjusted logistic, multinomial, and linear regression models were used to assess associations of excessive daytime sleepiness with AF, AF burden, and supraventricular arrhythmia burden.

RESULTS

Approximately 18% of the sample had excessive daytime sleepiness, and 8.5% had AF. After adjustment, excessive daytime sleepiness was not significantly associated with AF (odds ratio (OR), 1.20; Confidence Interval (CI), 0.81-1.75), continuous AF burden (OR, 1.36; CI, 0.85-2.16), or measures of supraventricular arrhythmia burden (SVE burden: β 0.01; 95% CI, -0.09-0.11; SVT burden: β 0.02; 95% CI, -0.04-0.08).

CONCLUSION

In this community-based sample of older adults, excessive daytime sleepiness was not associated with measures of arrhythmia burden. Future studies with objective measures of sleep are needed to further examine the role of sleep in the development and progression of arrhythmia burden.

Prospective association of obstructive sleep apnea risk factors with heart failure and its subtypes in postmenopausal women: The Women's Health Initiative

STUDY OBJECTIVES

The relationship between obstructive sleep apnea (OSA) and heart failure (HF) incidence in postmenopausal women has been understudied, given the limited representation of women in heart failure studies. We investigated the relationship between OSA risk factors and HF and its subtypes in postmenopausal women.

METHODS

We performed a prospective analysis on the adjudicated HF outcomes in the Women's Health Initiative from enrollment (1993-1998) to September 30, 2016. HF with preserved ejection fraction (HFpEF) and reduced ejection fraction (HFrEF) were defined as adjudicated acute HF hospitalization with EF ≥ 45% or < 45%, respectively. We employed Cox regression to examine the association between OSA risk factors and symptoms (individually and using a summary risk score) and time to first hospitalized HF.

RESULTS

Of 42,362 women, 2,205 (5.21%) developed all HF, 1,162 (2.74%) women developed HFpEF, and 679 (1.60%) developed HFrEF. Individual OSA risk factors and symptoms, including obesity (hazard ratio = 1.33, 95% confidence interval [CI] 1.20-1.48), snoring (hazard ratio = 1.30, 95% CI 1.16-1.46), and hypertension (HR = 1.45, 95% CI 1.35-1.56), were positively associated with risk of HF and HFpEF, but only hypertension was associated with HFrEF. When examined as a summary risk score compared with those with none of the OSA risk factors, presence of each additional factor was significantly associated with increased risk of hospitalized HF in a dose-response fashion for HFpEF (P trend < .001), but not HFrEF (P trend = .26).

CONCLUSIONS

OSA risk factors and symptoms were associated with HFpEF, but not HFrEF, among postmenopausal women and are largely dependent on body mass index, snoring, and hypertension.

Automatic positive airway pressure for obstructive sleep apnea in heart failure with reduced ejection fraction

Background

Moderate-to-severe obstructive sleep apnea (OSA) is highly prevalent in heart failure patients with reduced left ventricular ejection fraction (HFrEF), and is associated with worsening cardiac function and increased mortality.

Objectives

The automatic positive airway pressure (APAP) trial tested the impact of APAP treatment on changes for the pre-specified endpoints: changes in peak oxygen uptake (peak VO₂), percent-predicted peak VO₂ and oxygen uptake at anaerobic threshold (VO₂-AT).

Methods

This randomized, controlled pilot study included patients with chronic, stable HFrEF who had moderate-to-severe OSA. Patients were randomized 1:1 to either APAP (AutoSet™, ResMed) or nasal strips (control) for 6 months.

Results

76 patients have been randomized and 58 had complete data for final analysis. There was a statistically significant change in the APAP intervention arm for the primary endpoint percent-predicted peak VO₂ in comparison to control (67 ± 17 to 73 ± 19%; p = 0.01). Additional primary endpoints peak VO₂ and VO₂-AT showed a trend in increase in the APAP group. Moreover, there were significant improvements within the APAP group for hypoxemia, left ventricular function and quality of life from baseline to 6 months, but not within the control group (p = 0.001 and p = 0.037, respectively).

Conclusion

APAP intervention was shown to significantly improve outcome compared to control group, represented in percent-predicted peak VO₂, an established surrogate marker for cardiovascular prognosis in HFrEF. APAP has additional beneficial effects on hypoxemia, cardiac function and quality of life.

Sleep Disordered Breathing in Hospitalized African-Americans

RATIONALE

Sleep-disordered breathing (SDB) is a common disorder in general population, with higher prevalence in population with comorbid cardiovascular disease, and yet it remains frequently undiagnosed. Prior published data show that hospitalized obese patients have a high incidence of unrecognized SDB. However, limited data exists on the incidence, prevalence, and impact of SDB in hospitalized obese African-American (AA) patients. This study was performed to better understand the burden of undiagnosed SDB in hospitalized AA patients and its implications on readmission.

METHODS

A total of 1243 consecutive obese AA patients admitted to medical or telemetry service were screened utilizing a screening questionnaire (STOP/STOPBANG) from October 2016 to October 2017. If the results of the screening questionnaire were positive, the patients were offered inpatient testing with either High Resolution Pulse Oximetry (HRPO), or a type 3 portable monitor (PM). SDB was suspected if the Oxygen Desaturation Index (ODI) or Apnea Hypopnea Index (AHI) ≥ 5. We collected 30-day readmission and emergency department (ED) visit data on all patients and requested a formal outpatient sleep study for patients identified as SDB positive.

RESULTS

Of the 1243 AA patients screened, 852 (68.5%) patients screened positive for SDB. Of these high-risk screens, 538 (63.1%) patients underwent inpatient testing with either High Resolution Pulse Oximetry (HRPO) or PM. Of these 538 patients, 319 (59.3%) were found to have suspected obstructive sleep apnea (OSA) based on ODI/AHI >5. Mild SDB (AHI 5-14) was present in 149 (46.7%) patients; moderate (AHI 15-29) in 74 (23.2%) patients; and severe (AHI >30) in 96 (30.1%) patients. The patients with suspected SDB were educated and encouraged to get an out-patient polysomnogram (PSG) but only 32 (10.0%) returned to undergo a formal PSG. The 30-day readmission rate/ED visits for patient with SDB was 13.5% compared to 13.7% of patients without SDB.

CONCLUSION

This is the largest SDB registry that included obese hospitalized AA patients in a tertiary care academic center and reveals a high prevalence of undiagnosed SDB in this cohort. Despite proactive screening and patient education only 3.8% (32/852) of patients returned post-discharge for formal polysomnography. The presence of SDB did not impact the 30-day readmission rate/ED visit rate in this cohort.

Effectiveness of sleep surgery versus a mandibular advancement device for obstructive sleep apnea in terms of nocturnal cardiac autonomic activity

PURPOSE

Sleep surgery and mandibular advancement devices (MAD) are treatments for obstructive sleep apnea (OSA), but their comparative efficacy remains unclear. We compared their efficacy using various parameters.

METHODS

Subjects treated for OSA with sleep surgery or MAD (n = 30/group)-matched for sex, body mass index (BMI), and baseline apnea-hypopnea index (AHI)-were enrolled. The efficacy of these treatments according to polysomnographic parameters, sleep quality questionnaires, and heart rate variability (HRV) time- and frequency-domain parameters were compared between pre-treatment and 3-month post-treatment.

RESULTS

Polysomnographic and sleep quality questionnaire parameters improved significantly in both groups. In time-domain HRV analysis, average normal-to-normal intervals increased significantly in the surgery (942.2 ± 140.8 to 994.6 ± 143.1, P = 0.008) and MAD (901.1 ± 131.7 to 953.7 ± 123.1, P = 0.002) groups. Low frequency (LF) decreased significantly in the surgery group (P = 0.012); high frequency (HF) remained unchanged in both groups. The LF/HF ratio decreased in both groups (2.9 ± 1.8 to 2.3 ± 1.7, P = 0.017, vs. 3.0 ± 1.8 to 2.4 ± 1.4, P = 0.025). Normalized high frequency increased significantly in both groups (31.0 ± 13.2 to 36.8 ± 13.7, P = 0.009, vs. 29.1 ± 10.7 to 33.7 ± 12.5, P = 0.024), in contrast to normalized low frequency. However, no HRV parameter changes differed significantly between the groups after adjusting for age, BMI, and AHI.

CONCLUSION

Sleep surgery and MAD are equally effective treatments for OSA according to cardiac autonomic activity.

The use and effectiveness of adaptive servo ventilation in central sleep apnea: a study of consecutive sleep clinic patients

The use of adaptive servo ventilation to treat central sleep apnea in the clinical setting is incompletely understood and could be under-utilized. We reviewed our experience of adaptive servo ventilation use in patients with central sleep apnea. This study shows the effectiveness of adaptive servo ventilation in treating patients with central sleep apnea, irrespective of a predisposing factor, as assessed during a 4-week treatment trial. Results show that adaptive servo ventilation was effective and superior to continuous positive airway pressure in controlling central sleep apnea and improving symptoms. Only a small proportion of these patients had comorbid heart failure. Early treatment with adaptive servo ventilation may improve long-term adherence to therapy. These findings highlight the utility of adaptive servo ventilation in the management of central sleep apnea.

A Further Introduction to Dental Sleep Medicine

Dental sleep medicine traditionally focuses on sleep-related breathing disorders, such as snoring and obstructive sleep apnea. However, everyday practice shows that also other sleep disorders touch on dentistry, including sleep-related orofacial pain, xerostomia, hypersalivation, gastroesophageal reflux disease and bruxism. A new definition, which covers all the diagnostic and treatment aspects of these disorders, has therefore been formulated for dental sleep medicine. This article describes why this development started and sketches the current state of affairs regarding the discipline of dental sleep medicine. The different dental sleep disorders are also described briefly, with special focus on the more remarkable associations between them.

Prevalence, risk factors, and type of sleep apnea in patients with paroxysmal atrial fibrillation

Background

Recent studies have suggested an association between sleep apnea (SA) and atrial fibrillation (AF). We aimed to study the prevalence, characteristics, risk factors and type of sleep apnea (SA) in ablation candidates with paroxysmal AF.

Methods/Results

We prospectively studied 579 patients with paroxysmal AF, including 157 women (27.1%) and 422 men (72.9%). Mean age was 59.9 ± 9.6 years and mean body mass index (BMI) 28.5 ± 4.5 kg/m². SA was diagnosed using polygraphy for two nights at home. The Epworth Sleepiness Scale (ESS), STOP-Bang Questionnaire, and Berlin Questionnaire (BQ) assessed the degree of SA symptoms. A total of 479 (82.7%) patients had an apnea-hypopnea index (AHI) ≥ 5, whereas moderate-severe SA (AHI ≥ 15) was diagnosed in 244 patients (42.1%). The type of SA was predominantly obstructive, with a median AHI of 12.1 (6.7–20.6) (range 0.4–85.8). The median central apnea index was 0.3 (0.1–0.7). AHI increased with age, BMI, waist and neck circumference, body and visceral fat. Using the Atrial Fibrillation Severity Scale and the SF-36, patients with more severe SA had a higher AF burden, severity and symptom score and a lower Physical-Component Summary score. Age, male gender, BMI, duration of AF, and habitual snoring were independent risk factors in multivariate analysis (AHI ≥ 15). We found no association between ESS and AHI (R² = 0.003, p = 0.367).

Conclusions

In our AF population, SA was highly prevalent and predominantly obstructive. The high prevalence of SA detected in this study may indicate that SA is under-recognized in patients with AF. None of the screening questionnaires predicted SA reliably.

Obstructive sleep apnoea in acute coronary syndrome

Obstructive sleep apnoea (OSA) syndrome affects about 13% of the male and 7-9% of the female population. Hypoxia, oxidative stress and systemic inflammation link OSA and cardiovascular and metabolic consequences, including coronary artery disease. Current research has identified several clinical phenotypes, and the combination of breathing disturbances during sleep, systemic effects and end-organ damage might help to develop personalised therapeutic approaches. It is unclear whether OSA is a risk factor for acute coronary syndrome (ACS) and might affect its outcome. On the one hand, OSA in patients with ACS may worsen prognosis; on the other hand, OSA-related hypoxaemia could favour the development of coronary collaterals, thereby exerting a protective effect. It is unknown whether positive airway pressure treatment may influence adverse events and consequences of ACS. In non-sleepy patients with OSA and stable coronary artery disease, randomised controlled trials failed to show that continuous positive airway pressure (CPAP) treatment protected against cardiovascular events. Conversely, uncontrolled studies suggested positive effects of CPAP treatment in such patients. Fewer data are available in subjects with ACS and OSA, and results of randomised controlled studies on the effects of CPAP are expected shortly. Meanwhile, the search for reliable markers of risk continues. Recent studies suggest that daytime sleepiness may indicate a more severe OSA phenotype with regard to cardiovascular risk. Finally, some studies suggest sex-related differences. The picture is still incomplete, and the potential role of OSA in patients with ACS awaits confirmation, as well as clear definition of subgroups with different degrees of risk.

Particularities of Older Patients with Obstructive Sleep Apnea and Heart Failure with Mid-Range Ejection Fraction

Background and objectives: Obstructive sleep apnea syndrome (OSAS) and heart failure (HF) are increasing in prevalence with a greater impact on the health system. The aim of this study was to assess the particularities of patients with OSAS and HF, focusing on the new class of HF with mid-range ejection fraction (HFmrEF, EF = 40%-49%), and comparing it with reduced EF (HFrEF, EF < 40%) and preserved EF (HFpEF, EF ≥ 50%). Materials and Methods: A total of 143 patients with OSAS and HF were evaluated in three sleep labs of "Victor Babes" Hospital and Cardiovascular Institute, Timisoara, Western Romania. We collected socio-demographic data, anthropometric sleep-related measurements, symptoms through sleep questionnaires and comorbidity-related data. We performed blood tests, cardio-respiratory polygraphy and echocardiographic measurements. Patients were divided into three groups depending on ejection fraction. Results: Patients with HFmrEF were older (p = 0.0358), with higher values of the highest systolic blood pressure (mmHg) (p = 0.0016), higher serum creatinine (p = 0.0013), a lower glomerular filtration rate (p = 0.0003), higher glycemic levels (p = 0.008) and a larger left atrial diameter (p = 0.0002). Regarding comorbidities, data were presented as percentage, HFrEF vs. HFmrEF vs. HFpEF. Higher prevalence of diabetes mellitus (52.9 vs. 72.7 vs. 40.2, p = 0.006), chronic kidney disease (17.6 vs. 57.6 vs. 21.5, p < 0.001), tricuspid insufficiency (76.5 vs. 84.8 vs.59.1, p = 0.018) and aortic insufficiency (35.3 vs.42.4 vs. 20.4, p = 0.038) were observed in patients with HFmrEF, whereas chronic obstructive pulmonary disease(COPD) (52.9 vs. 24.2 vs.18.3, p = 0.009), coronary artery disease(CAD) (82.4 vs. 6.7 vs. 49.5, p = 0.026), myocardial infarction (35.3 vs. 24.2 vs. 5.4, p < 0.001) and impaired parietal heart kinetics (70.6 vs. 68.8 vs. 15.2, p < 0.001) were more prevalent in patients with HFrEF. Conclusions: Patients with OSAS and HF with mid-range EF may represent a new group with increased risk of developing life-long chronic kidney disease, diabetes mellitus, tricuspid and aortic insufficiency. COPD, myocardial infarction, impaired parietal kinetics and CAD are most prevalent comorbidities in HFrEF patients but they are closer in prevalence to HFmrEF than HFpEF.

More than Heart Failure: Central Sleep Apnea and Sleep-Related Hypoventilation

Central sleep apnea (CSA) comprises a variety of breathing patterns and clinical entities. They can be classified into 2 categories based on the partial pressure of carbon dioxide in the arterial blood. Nonhypercapnic CSA is usually characterized by a periodic breathing pattern, while hypercapnic CSA is based on hypoventilation. The latter CSA form is associated with central nervous, neuromuscular, and rib cage disorders as well as obesity and certain medication or substance intake. In contrast, nonhypercapnic CSA is typically accompanied by an overshoot of the ventilation and often associated with heart failure, cerebrovascular diseases, and stay in high altitude. CSA and hypoventilation syndromes are often considered separately, but pathophysiological aspects frequently overlap. An integrative approach helps to recognize underlying pathophysiological mechanisms and to choose adequate therapeutic strategies. Research in the last decades improved our insights; nevertheless, diagnostic tools are not always appropriately chosen to perform comprehensive sleep studies. This supports misinterpretation and misclassification of sleep disordered breathing. The purpose of this article is to highlight unresolved problems, raise awareness for different pathophysiological components and to discuss the evidence for targeted therapeutic strategies.

Epicardial fat accumulation is an independent marker of impaired heart rate recovery in obese patients with obstructive sleep apnea

BACKGROUND

Sympathetic nervous system activation plays a pivotal role in obese patients with obstructive sleep apnea (OSA), contributing to increased cardiovascular risk. Epicardial adipose tissue (EAT) activates cardiac autonomic nervous system. Our main study objective was to investigate effects of these autonomic dysfunction factors on post-exercise heart rate recovery (HRR).

METHODS

36 patients, referred for clinical assessment of obesity (BMI > 30 kg/m²), underwent overnight polysomnography, transthoracic echocardiography and cardiopulmonary exercise testing.

RESULTS

Compared to non-OSA patients, OSA patients were older and displayed reduced body weight-indexed peak VO₂. Cardiac output at peak exercise was similar among groups. Peak exercise arterio-venous oxygen content difference D[a-v]O₂ was lower in OSA patients. In univariate linear analysis, age, AHI, EAT thickness, peak VO₂ and diabetes were associated with blunted HRR. Multiple linear regression analysis showed that increased EAT thickness, AHI and diabetes were independently associated with lower HRR. For identical AHI value and diabetes status, HRR significantly decreased by 61.7% for every 1 mm increase of EAT volume (p = 0.011). If HRR was treated as a categorical variable, EAT [odds ratio (OR) 1.78 (95% confidence interval [CI] 1.19-2.66); p = 0.005], and type 2 diabetes [OR 8.97 (95% CI 1.16-69.10); p = 0.035] were the only independent predictors of blunted HRR.

CONCLUSIONS

Aerobic capacity and peak exercise D[a-v]O₂ are impaired in obese OSA patients, suggesting abnormal peripheral oxygen extraction. EAT thickness is an independent marker of post-exercise HRR, which is a noninvasive marker of autonomic nerve dysfunction accompanying poor cardiovascular prognosis in obese patients.