Heart failure and sleep disorders

Design, manufacture, and control of a low-cost positive airway pressure device

Current positive airway pressure devices cost NZ$800-$2500, posing a financial barrier for the estimated 1 billion individuals worldwide with sleep apnea and those researching respiratory diseases. Increasing diagnoses and research interest in the area necessitate a low-cost, easily accessible alternative. Thus, the mePAP, a high-quality, multipurpose, low-cost (∼NZ$250) positive airway pressure device, was designed and prototyped specifically for respiratory disease research, particularly for sleep apnea. The mePAP allows user customization and provides researchers with an affordable tool for testing positive airway pressure algorithms. Unlike typical commercial devices, the mePAP offers adaptability with open-source data collection and easily modifiable software for implementing and analysing different control and diagnostic algorithms. It features three control modes: constant; bilevel; and automatic; and provides pressures from 4 to 20 cmH2O, controlled via a phone app through Wi-Fi, with a mini-sensor added at the mask for increased accuracy. Validation tests showed the mePAP's performance is comparable to a gold-standard Fisher & Paykel device, with extremely similar output pressures. The mePAP's low cost enhances accessibility and equity, allowing researchers to test ventilation algorithms for sleep apnea and other respiratory conditions, with all data openly available for analysis. Its adaptability and multiple applications increase its usability and usefulness across various research and clinical settings.

Development and validation of a prediction nomogram for sleep disorders in hospitalized patients with acute myocardial infarction

PURPOSE

Sleep disorders are becoming more prevalent in hospitalized patients with acute myocardial infarction (AMI). We aimed to investigate the risk factors for sleep disorders in hospitalized patients with AMI, then develop and validate a prediction nomogram for the risk of sleep disorders.

METHODS

Clinical data were collected from patients with AMI hospitalized in our hospital from January 2020 to June 2023. All patients were divided into the training group and the validation group with a ratio of 7:3 in sequential order. The LASSO regression analysis and multivariate logistic regression analysis were used to screen potential risk factors for sleep disorders. The concordance index (C-index), calibration curves, and decision curve analysis (DCA) were plotted.

RESULTS

A total of 256 hospitalized patients with AMI were enrolled. Patients were divided into the training group (180) and the validation group (76) according to a scale of 7:3. Of the 256 patients, 90 patients (35.16%) suffered from sleep disorders, and 33 patients (12.89%) needed hypnotics. The variables screened by LASSO regression included age, smoking, NYHA class, anxiety status at admission, depression status at admission, and strangeness of environment. A nomogram model was established by incorporating the risk factors selected. The C-index, calibration curve, and DCA showed good predictive performance.

CONCLUSIONS

We identified six clinical characteristics as predictors of sleep disorders in hospitalized patients with AMI. It helps nurses make appropriate decisions in clinical practice.

Effect of SGLT2-Inhibitors on Polygraphic Parameters in Elderly Patients Affected by Heart Failure, Type 2 Diabetes Mellitus, and Sleep Apnea

Obstructive sleep apneas (OSAs) and central sleep apneas (CSAs) are the most common comorbidities in Heart Failure (HF) that are strongly associated with all-cause mortality. Several therapeutic approaches have been used to treat CSA and OSA, but none have been shown to significantly improve HF prognosis. Our study evaluated the effects of a 3-months treatment with sodium-glucose cotransporter type 2 inhibitor (SGLT2i) on polygraphic parameters in patients with sleep apnea (SA) and HF, across the spectrum of ejection fraction, not treated with continuous positive air pressure (CPAP). A group of 514 consecutive elderly outpatients with HF, type 2 diabetes mellitus (T2DM) and SA, eligible for treatment with SGLT2i, were included in the investigation before starting any CPAP therapy. The two groups were compared with the t-test and Mann-Whitney test for unpaired data when appropriate. Then, a simple logistic regression model was built using 50% reduction in AHI as the dependent variable and other variables as covariates. A multivariate stepwise logistic regression model was constructed using the variables that linked with the dependent variable to calculate the odds ratio (OR) for the independent predictors associated with the reduction of 50% in AHI. The treated group experienced significant improvements in polygraphic parameters between baseline values and follow-up with reduction in AHI (28.4 ± 12.9 e/h vs. 15.2 ± 6.5 e/h; p < 0.0001), ODI (15.4 ± 3.3 e/h vs. 11.1 ± 2.6 e/h; p < 0.0001), and TC90 (14.1 ± 4.2% vs. 8.2 ± 2.0%; p < 0.0001), while mean SpO2 improved (91. 3 ± 2.3 vs. 93.8 ± 2.5); p < 0.0001. These benefits were not seen in the untreated population. The use of SGLT2i in patients suffering from HF and mixed-type SA not on CPAP therapy significantly contributes to improving polygraphic parameters.

Sleep fragmentation induces heart failure in a hypertrophic cardiomyopathy mouse model by altering redox metabolism

Sleep fragmentation (SF) disrupts normal biological rhythms and has major impacts on cardiovascular health; however, it has never been shown to be a risk factor involved in the transition from cardiac hypertrophy to heart failure (HF). We now demonstrate devastating effects of SF on hypertrophic cardiomyopathy (HCM). We generated a transgenic mouse model harboring a patient-specific myosin binding protein C3 (MYBPC3) variant displaying HCM, and measured the progression of pathophysiology in the presence and absence of SF. SF induces mitochondrial damage, sarcomere disarray, and apoptosis in HCM mice; these changes result in a transition of hypertrophy to an HF phenotype by chiefly targeting redox metabolic pathways. Our findings for the first time show that SF is a risk factor for HF transition and have important implications in clinical settings where HCM patients with sleep disorders have worse prognosis, and strategic intervention with regularized sleep patterns might help such patients.

Heart failure with preserved ejection fraction risk is associated with prevalence and severity of obstructive sleep apnea

STUDY OBJECTIVES

While heart failure with preserved ejection fraction (HFpEF) is associated with the presence of obstructive sleep apnea (OSA), few studies have examined the association between scoring systems used to predict HFpEF risk, such as the H2FPEF and HFA-PEFF scores, and OSA prevalence and severity.

METHODS

We performed chart review on all patients who underwent both an echocardiogram and sleep study at the University of Pennsylvania between July 1, 2020, and June 30, 2022. There were 277 patients in the final cohort after excluding patients with relevant comorbidities. Associations between echocardiographic parameters and OSA severity, as well as between H2FPEF score and OSA severity, were examined using linear tests of trend. The association between H2FPEF score and prevalent OSA was examined with logistic regression.

RESULTS

OSA severity was associated with echocardiographic markers, including left atrial volume index (P = .03) and left ventricular relative thickness (P = .008). Patients with high H2FPEF risk scores had over 17-fold higher odds of prevalent OSA compared with those with low-risk scores (17.7; 95% CI 4.3, 120.7; P < .001). Higher H2FPEF scores were strongly correlated with OSA severity (P < .001). After controlling for body mass index, H2FPEF scores were not associated with prevalence or severity of OSA.

CONCLUSIONS

In an ambulatory population referred for sleep study and echocardiogram, markers of diastolic dysfunction were associated with OSA severity. OSA prevalence and severity were associated with increased H2FPEF scores, although these associations were largely explained by obesity. Clinicians should have low thresholds for referring patients with OSA for cardiac workup and patients with HFpEF for sleep study.

CITATION

Connolly JE, Genuardi MV, Mora JI, Prenner SB. Heart failure with preserved ejection fraction risk is associated with prevalence and severity of obstructive sleep apnea. J Clin Sleep Med. 2024;20(3):381-387.

The effect of using a sports application on the quality of sleep in patients with heart failure: a randomized clinical trial study

BACKGROUND

Patients with heart failure often suffer from sleep disorders. Due to the side effects of medications used to treat this disorder, non-pharmacological methods may be used to improve these patients' sleep quality. This study aimed to determine the effect of a sports application on sleep quality in patients with heart failure.

METHODS

In this single-blinded randomized clinical trial, 60 patients aged 30-70 referred to Shafa Hospital in Kerman were randomly assigned to control (n = 30) and intervention (n = 30) groups based on convenience sampling. The intervention group used the sports application for eight consecutive weeks. Data was collected using a demographic questionnaire and the Pittsburgh Sleep Quality Index (PSQI). An independent t-test and a Mann-Whitney U test were used for comparisons between groups and paired t-tests and Wilcoxon tests were used for comparisons within groups.

RESULTS

The data analysis revealed a significant difference in sleep quality scores between the two groups after the intervention, meaning that the intervention group had better sleep quality than the control group (P < 0.05).

CONCLUSIONS

As a result of the study, it was found that the sport application improved the quality of sleep in patients with heart failure. Our recommendation is for healthcare providers to use this sports application to present educational content related to physical activity and improve the sleep quality of patients.

TRIAL REGISTRATION

Iranian Registry of Clinical Trials: IRCT. 2019123045475N1." Registered 16 December 2019.

Sleep quality, fatigue, societal participation and health-related quality of life in kidney transplant recipients: a cross-sectional and longitudinal cohort study

BACKGROUND

Fatigue and impaired health-related quality of life (HRQoL) are common among kidney transplant recipients (KTR). We hypothesized that both may partially be attributable to poor sleep.

METHODS

Cross-sectional and longitudinal data of KTR enrolled in the TransplantLines Biobank and Cohort Study were used. Sleep quality was assessed using the Pittsburgh Sleep Quality Index questionnaire. Individual strength (i.e. a composite of fatigue, concentration, motivation and physical activity), societal participation and HRQoL were assessed using validated questionnaires.

RESULTS

We included 872 KTR (39% female, age 56 ± 13 years) and 335 healthy controls. In total, 33% of male KTR and 49% of female KTR reported poor sleep quality, which was higher compared with male and female healthy controls (19% and 28%, respectively, P < .001 for both). In logistic regression analyses, female sex, anxiety, active smoking, low protein intake, physically inactive lifestyle, low plasma magnesium concentration, using calcineurin inhibitors, not using mTOR inhibitors and using benzodiazepine agonists were associated with poor sleep quality. In adjusted linear regression analyses, poor sleep was strongly and independently associated with lower individual strength [standardized β (st.β) = 0.59, 95% confidence interval (CI) 0.45 to 0.74, P < .001], poorer societal participation (frequency: st.β = -0.17, 95% CI -0.32 to -0.01, P = .04; restrictions: st.β = -0.36, 95% CI -0.51 to -0.21, P < .001; satisfaction: st.β = -0.44, 95% CI -0.59 to -0.28, P < .001) and lower HRQoL (physical: st.β = -0.53, 95% CI -0.68 to -0.38, P < .001; mental: st.β = -0.64, 95% CI -0.78 to -0.50, P < .001). The associations with poorer societal participation and lower HRQoL were strongly mediated by individual strength (P < .001 for all), yet the suggested direct effects of poor sleep quality on HRQoL remained significant (Pphysical = .03, Pmental = .002). Longitudinal data of 292 KTR showed that sleep quality improves after kidney transplantation in males (P < .001), but not in females (P = .9).

CONCLUSIONS

Poor sleep quality is common among KTR, and may be a potential target to improve fatigue, societal participation and HRQoL among KTR.

Obstructive sleep apnea-related knowledge, attitude, experience, and behaviors among orthodontic professionals: a survey

PURPOSE

To assess obstructive sleep apnea (OSA)-related experience, knowledge, attitude, and behaviors among orthodontic professionals in China and identify factors associated with their knowledge levels, attitude toward referring, and self-confidence in the management of patients with OSA.

METHODS

An online cross-sectional survey was conducted using a 31-item questionnaire developed with a professional online survey tool ( www.wjx.cn ) and distributed via WeChat (Tencent, Shenzhen, China). Data were collected between January 16 and 23, 2022 and analyzed using the chi-square test, Fisher's exact test, and multivariate generalized estimation equations.

RESULTS

A total of 1760 professionals responded to the survey, and responses to 1611 questionnaires were valid. The average score of correct answers to the 15 OSA knowledge questions was 12.1 ± 2.0. Most of the professionals agreed that it was necessary to identify patients who might have OSA in practice. The top three sources for gaining knowledge of OSA according to the survey were classrooms and textbooks (76.3%), medical lectures (75.7%), and academic conferences (73.2%). The level of knowledge was significantly correlated with self-confidence in treatment (P < 0.001) and willingness to refer patients to otolaryngologists or clinicians of related disciplines (P < 0.001).

CONCLUSIONS

Most orthodontic professionals agreed that there was a need to identify patients with OSA and learn further about related problems. Treatment confidence and willingness of professionals to refer patients were related to the level of OSA knowledge. These findings suggest that promotion of OSA-related education may help improve the care of patients with OSA.

Blood pressure control in hypertensive sleep apnoea patients of the European Sleep Apnea Database cohort - effects of positive airway pressure and antihypertensive medication

Aims

We analysed longitudinal blood pressure (BP) data from hypertensive obstructive sleep apnoea (OSA) patients in the European Sleep Apnea Database cohort. The study investigated the interaction between positive airway pressure (PAP)-induced BP change and antihypertensive treatment (AHT).

Methods and results

Hypertensive patients with AHT [monotherapy/dual therapy n = 1283/652, mean age 59.6 ± 10.7/60.6 ± 10.3 years, body mass index (BMI) 34.2 ± 6.5/34.8 ± 7.0 kg/m2, apnoea-hypopnoea index 46 ± 25/46 ± 24 n/h, proportion female 29/26%, respectively] started PAP treatment. Office BP at baseline and 2- to 36-month follow-up were assessed. The interaction between AHT drug classes and PAP on BP was quantified and the influences of age, gender, BMI, co-morbidities, BP at baseline, and study site were evaluated. Following PAP treatment (daily usage, 5.6 ± 1.6/5.7 ± 1.9 h/day), systolic BP was reduced by -3.9 ± 15.5/-2.8 ± 17.7 mmHg in mono/dual AHT and diastolic BP by -3.0 ± 9.8/-2.7 ± 10.8 mmHg, respectively, all P < 0.0001. Systolic and diastolic BP control was improved following PAP treatment (38/35% to 54/46% and 67/67% to 79/74%, mono/dual AHT, respectively). PAP treatment duration predicted a larger BP improvement in the monotherapy group. Intake of renin-angiotensin blockers [angiotensin converting enzyme inhibitor (ACEI)/angiotensin receptor blocker (ARB)] alone or in any AHT combination was associated with better BP control. The AHT-dependent BP improvement was independent of confounders.

Conclusion

In this pan-European OSA patient cohort, BP control improved following initiation of PAP. Longer PAP treatment duration, was associated with a favourable effect on BP. Our study suggests that ACEI/ARB, alone or in combination with other drug classes, provides a particularly strong reduction of BP and better BP control when combined with PAP in OSA.

Screening obstructive sleep apnea patients via deep learning of knowledge distillation in the lateral cephalogram

The lateral cephalogram in orthodontics is a valuable screening tool on undetected obstructive sleep apnea (OSA), which can lead to consequences of severe systematic disease. We hypothesized that a deep learning-based classifier might be able to differentiate OSA as anatomical features in lateral cephalogram. Moreover, since the imaging devices used by each hospital could be different, there is a need to overcome modality difference of radiography. Therefore, we proposed a deep learning model with knowledge distillation to classify patients into OSA and non-OSA groups using the lateral cephalogram and to overcome modality differences simultaneously. Lateral cephalograms of 500 OSA patients and 498 non-OSA patients from two different devices were included. ResNet-50 and ResNet-50 with a feature-based knowledge distillation models were trained and their performances of classification were compared. Through the knowledge distillation, area under receiver operating characteristic curve analysis and gradient-weighted class activation mapping of knowledge distillation model exhibits high performance without being deceived by features caused by modality differences. By checking the probability values predicting OSA, an improvement in overcoming the modality differences was observed, which could be applied in the actual clinical situation.

Predictors of Nocturnal Hypoxemic Burden in Patients Undergoing Elective Coronary Artery Bypass Grafting Surgery

Background: Nocturnal hypoxemia has been linked to increased cardiovascular morbidity and mortality. Several common diseases, such as sleep-disordered breathing (SDB), heart failure (HF), obesity, and pulmonary disease, coincide with an elevated nocturnal hypoxemic burden with and without repetitive desaturations. Research question: This study aimed to evaluate the association of relevant common diseases with distinctive metrics of nocturnal hypoxemic burden with and without repetitive desaturations in patients undergoing coronary artery bypass grafting surgery. Study design and methods: In this subanalysis of the prospective observational study, CONSIDER-AF (NCT02877745) portable SDB monitoring was performed on 429 patients with severe coronary artery disease the night before cardiac surgery. Pulse oximetry was used to determine nocturnal hypoxemic burden, as defined by total recording time spent with oxygen saturation levels < 90% (T90). T90 was further characterized as T90 due to intermittent hypoxemia (T90desaturation) and T90 due to nonspecific and noncyclic SpO2-drifts (T90non-specific). Results: Multivariable linear regression analysis identified SDB (apnea-hypopnea-index ≥ 15/h; B [95% CI]: 6.5 [0.4; 12.5], p = 0.036), obesity (8.2 [2.5; 13.9], p = 0.005), and mild-to-moderate chronic obstructive pulmonary disease (COPD, 16.7 [8.5; 25.0], p < 0.001) as significant predictors of an increased nocturnal hypoxemic burden. Diseases such as SDB, obesity and HF were significantly associated with elevated T90desaturation. In contrast, obesity and mild-to-moderate COPD were significant modulators of T90non-specific. Interpretation: SDB and leading causes for SDB, such as obesity and HF, are associated with an increased nocturnal hypoxemic burden with repetitive desaturations. Potential causes for hypoventilation syndromes, such as obesity and mild-to-moderate COPD, are linked to an increased hypoxemic burden without repetitive desaturations. Clinical Trial Registration: ClinicalTrials.gov identifier: NCT02877745.

The Current Role of Cardiopulmonary Exercise Test in the Diagnosis and Management of Pulmonary Hypertension

Pulmonary arterial hypertension (PAH) is a progressive disease with a poor prognosis if left untreated. Despite remarkable achievements in understanding disease pathophysiology, specific treatments, and therapeutic strategies, we are still far from a definitive cure for the disease, and numerous evidences have underlined the importance of early diagnosis and treatment to improve the prognosis. Cardiopulmonary exercise testing (CPET) is the gold standard for assessing functional capacity and evaluating the pathophysiological mechanisms underlying exercise limitation. As effort dyspnea is the earliest and one of the main clinical manifestations of PAH, CPET has been shown to provide valid support in early detection, differential diagnosis, and prognostic stratification of PAH patients, being a useful tool in both the first approach to patients and follow-up. The purpose of this review is to present the current applications of CPET in pulmonary hypertension and to propose possible future utilization to be further investigated.

Computational Biomechanics of Sleep: A Systematic Mapping Review

Biomechanical studies play an important role in understanding the pathophysiology of sleep disorders and providing insights to maintain sleep health. Computational methods facilitate a versatile platform to analyze various biomechanical factors in silico, which would otherwise be difficult through in vivo experiments. The objective of this review is to examine and map the applications of computational biomechanics to sleep-related research topics, including sleep medicine and sleep ergonomics. A systematic search was conducted on PubMed, Scopus, and Web of Science. Research gaps were identified through data synthesis on variants, outcomes, and highlighted features, as well as evidence maps on basic modeling considerations and modeling components of the eligible studies. Twenty-seven studies (n = 27) were categorized into sleep ergonomics (n = 2 on pillow; n = 3 on mattress), sleep-related breathing disorders (n = 19 on obstructive sleep apnea), and sleep-related movement disorders (n = 3 on sleep bruxism). The effects of pillow height and mattress stiffness on spinal curvature were explored. Stress on the temporomandibular joint, and therefore its disorder, was the primary focus of investigations on sleep bruxism. Using finite element morphometry and fluid-structure interaction, studies on obstructive sleep apnea investigated the effects of anatomical variations, muscle activation of the tongue and soft palate, and gravitational direction on the collapse and blockade of the upper airway, in addition to the airflow pressure distribution. Model validation has been one of the greatest hurdles, while single-subject design and surrogate techniques have led to concerns about external validity. Future research might endeavor to reconstruct patient-specific models with patient-specific loading profiles in a larger cohort. Studies on sleep ergonomics research may pave the way for determining ideal spine curvature, in addition to simulating side-lying sleep postures. Sleep bruxism studies may analyze the accumulated dental damage and wear. Research on OSA treatments using computational approaches warrants further investigation.

Impact of sleep apnoea on 30 day hospital readmission rate and cost in heart failure with reduced ejection fraction

AIMS

In this study, we estimated the 30 day all-cause and heart failure-specific readmission rates, predictors, mortality, and hospitalization costs in patients with obstructive sleep apnoea admitted with acute decompensated heart failure with reduced ejection fraction.

METHODS AND RESULTS

This is a retrospective cohort study using the Agency of Healthcare Research and Quality's National Readmission Database for the year 2019. The primary outcome was the 30 day all-cause hospital readmission rate. The secondary outcomes were (i) in-hospital mortality rate for index admissions; (ii) 30 day mortality rate for index hospitalizations; (iii) the five most common principal diagnosis for readmission; (iv) readmission in-hospital mortality rate; (v) length of hospital stay; (vi) independent risk factors for readmission; and (vii) hospitalization costs. We identified 6908 hospitalizations that met our study definition. The mean patient age was 62.8 years, and women comprised only 27.6% of patients. The 30 day all-cause readmission rate was 23.4%. 48.9% of readmissions were due to decompensated heart failure. The in-hospital mortality rate during readmissions was significantly higher than that of the index admission (5.6% vs. 2.4%; P < 0.05). The mean length of stay for patients during index admissions was 6.5 days (6.06-7.02), while during readmissions, it was 8.5 days (7.4-9.6; P < 0.05). The mean total hospitalization charges at index admissions were $78 438 (68 053-88 824), while during readmissions, they were higher at $124 282 (90 906-157 659; P < 0.05). The mean total cost of hospitalization during index admissions was $20 535 (18 311-22 758), while at readmissions, it was higher at $29 954 (24 041-35 867; P < 0.05). The total hospital charges for all 30 day readmissions were $195 million, and total hospital costs was $46.9 million. The variables found to be associated with increased rate of readmissions were patients with Medicaid insurance, higher Charlson co-morbidity Index, and longer length of stay. The variables associated with lower rate of readmissions were prior percutaneous coronary intervention and patients with private insurance.

CONCLUSIONS

In patients with obstructive sleep apnoea admitted with heart failure with reduced ejection fraction, we found a substantial all-cause readmission rate of 23.4% with heart failure readmission constituting about 48.9% of readmissions. Readmissions were associated with higher mortality and resource use.

Network pharmacology and molecular docking prediction, combined with experimental validation to explore the potential mechanism of Qishen Yiqi pills against HF-related cognitive dysfunction

ETHNOPHARMACOLOGICAL RELEVANCE

Qishen Yiqi Pills (QSYQ) is a classical herbal formula for treating heart failure (HF) and has potential efficacy in improving cognitive function. The latter is one of the most common complications in patients with HF. However, there is no study on treating HF-related cognitive dysfunction by QSYQ.

AIMS OF THE STUDY

The study aims to investigate the effect and mechanism of QSYQ on treating post-HF cognitive dysfunction based on network pharmacology and experimental validation.

MATERIALS AND METHODS

Network pharmacology analysis and molecular docking was used to explore endogenous targets of QSYQ in treating cognitive impairment. Ligation of the anterior descending branch of the left coronary artery and sleep deprivation (SD) were used to induce HF-related cognitive dysfunction in rats. The efficacy and potential signal targets of QSYQ were then verified by functional evaluation, pathological staining, and molecular biology experiments.

RESULTS

384 common targets were identified by intersecting QSYQ 'compound targets' and 'cognitive dysfunction' disease targets. KEGG analysis showed these targets were enriched to the cAMP signal, and four marks responsible for regulating the cAMP signal were successfully docked with core compounds of QSYQ. Animal experiments demonstrated that QSYQ significantly ameliorated cardiac function and cognitive function in rats suffering from HF and SD, inhibited the reduction of cAMP and BDNF content, reversed the upregulation of PDE4 and downregulation of CREB, suppressed the loss of neurons, and restored the expression of synaptic protein PSD95 in the hippocampus.

CONCLUSION

This study clarified that QSYQ could improve HF-related cognitive dysfunction by modulating cAMP-CREB-BDNF signals. It provides a rich basis for the potential mechanism of QSYQ in the treatment of heart failure with cognitive dysfunction.

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.

Effects of continuous positive airway pressure therapy on left ventricular performance in patients with severe obstructive sleep apnea

We investigated myocardial performance concerning obstructive sleep apnea (OSA) severity and the benefits of continuous positive airway pressure (CPAP) therapy. In this randomized sham-controlled trial, 52 patients (mean age, 49 years; 92%, males; mean AHI, 59) with severe OSA were randomly assigned to receive either CPAP or sham treatment for 3 months. The severity of OSA was determined using the apnea/hypopnea index (AHI), oxygen desaturation index (ODI), percentage of sleep time below 90% oxygen saturation (T90), and average O₂ saturation during sleep (mean SpO₂). We compared the changes in myocardial work after 3 months of CPAP (n = 26) versus the sham group (n = 26) at rest and during an exercise stress test. Unlike AHI or ODI, indices of hypoxemia including T90 and mean SpO₂ were significantly correlated with global constructive work, as defined by work of left ventricle (LV) that contributes to LV ejection during systole (T90, β = 0.393, p = 0.012; mean SpO₂, β = 0.331, p = 0.048), and global wasted work (GWW), as defined by work of LV that does not contribute to LV ejection (T90, β = 0.363, p = 0.015; mean SpO₂, β =  - 0.370, p = 0.019). After 3 months, GWW decreased (80.0 ± 49.2 to 60.8 ± 26.3, p = 0.009) and global work efficiency increased (94.0 ± 4.5 to 95.7 ± 2.0, p = 0.008) in the CPAP group compared to those in the sham group. At the 3-month follow-up exercise stress echocardiography, worsening of GWW during exercise was significantly decreased in the CPAP group compared to that in the sham group (p = 0.045 at 50 W). Hypoxemia indices were closely associated with myocardial performance in patients with severe OSA. CPAP treatment for 3 months improved left ventricular myocardial performance by decreasing wasted work and increasing work efficacy compared to the sham treatment.

A State-of-the-Art Review on Sleep Apnea Syndrome and Heart Failure

Heart failure (HF) affects many patients worldwide every year. It represents a leading cause of hospitalization and still, today, mortality remains high, albeit the progress in treatment strategies. Several factors contribute to the development and progression of HF. Among these, sleep apnea syndrome represents a common but still underestimated factor because its prevalence is substantially higher in patients with HF than in the general population and is related to a worse prognosis. This review summarizes the current knowledge about sleep apnea syndrome coexisting with HF in terms of morbidity and mortality to provide actual and future perspectives about the diagnosis, evaluation, and treatment of this association.

Interaction effects between sleep disorders and depression on heart failure

BACKGROUND

Sleep disorders and depression were recognized as independent risk factors for heart failure, whether their interaction effects also correlated with the risk of heart failure remains elusive. This study was to explore the interaction effects between sleep disorders and depression on the risk of heart failure.

METHODS

This was a cross-sectional study that included data from 39,636 participants in the National Health and Nutritional Examination Survey (NHANES) database. Poisson regression model was applied to evaluate the associations of depression or sleep disorders with heart failure. The relative excess risk of interaction (RERI), attributable proportion of interaction (API) and synergy index (SI) were used to measure whether the interaction effects between depression and sleep disorders on heart failure was statistically significant.

RESULTS

The risk of heart failure was increased in people with sleep disorders [risk ratio (RR) = 1.92, 95% confidence interval (CI): 1.68-2.19) after adjusting for confounders including age, gender, body mass index (BMI), race, marital status, education level, annual family income, drinking history, smoking history, diabetes, hypertension and stroke. The risk of heart failure was elevated in patients with depression after adjusting for confounders (RR = 1.96, 95%CI: 1.65-2.33). Patients with depression and sleep disorders were associated with increased risk of heart failure after adjusting for confounders (RR = 2.76, 95%CI: 2.23-3.42). The CIs of interactive indexes RERI was -0.42 (95%CI: -1.23-0.39), and API was -0.15 (95%CI: -0.46-0.16), which included 0. The CI of interactive indexes SI was 0.81 (95%CI: 0.54-1.21), which contained 1.

CONCLUSION

Depression and sleep disorders were independent risk factors for heart failure but the interaction effects between depression and sleep disorders on the occurrence of heart failure were not statistically different.

One-year mortality after hospitalization for acute heart failure: Predicting factors (PRECIC study subanalysis)

INTRODUCTION AND OBJECTIVES

One-year mortality after hospitalization for heart failure (HF) is high. This study aims to identify predictive factors of one-year mortality.

METHODS

This is a retrospective, single-center and observational study. All patients hospitalized for acute HF for one-year were enrolled.

RESULTS

A total of 429 patients were enrolled, mean age of 79 years. The in-hospital and one-year all-cause mortality rates were 7.9% and 34.3%, respectively. In the univariable analysis, the factors significantly associated with higher one-year mortality risk were: age ≥80 years (odds ratio (OR)=2.05, 95% confidence interval (CI) 1.35-3.11, p=0.001); active cancer (OR=2.93, 95% CI 1.36-6.32, p=0.008); dementia (OR=2.84, 95% CI 1.81-4.47, p<0.001); functional dependency (OR=2.63, 95% CI 1.65-4.19, p<0.001); atrial fibrillation (OR=1.86, 95% CI 1.24-2.80, p=0.004); higher creatinine (OR=2.03, 95% CI 1.29-3.21, p=0.002), urea (OR=2.92, 95% CI 1.95-4.36, p<0.001) and red cell distribution width (RDW; 4thQ OR=5.59, 95% CI 3.03-10.32, p=0.001); and lower hematocrit (OR=0.94, 95% CI 0.91-0.97, p<0.001), hemoglobin (OR=0.83, 95% CI 0.75-0.92, p<0.001) and platelet distribution width (PDW; OR=0.89, 95% CI 0.82-0.97, p=0.005). In the multivariable analysis, the independent predictors of higher one-year mortality risk were: age ≥80 years (OR=2.05, 95% CI 1.21-3.48); active cancer (OR=2.70, 95% CI 1.03-7.01); dementia (OR=2.69, 95% CI 1.53-4.74); higher urea (OR=2.97, 95% CI 1.84-4.80) and RDW (4thQ OR=5.24, 95% CI 2.55-10.76); and lower PDW (OR=0.88, 95% CI 0.80-0.97).

CONCLUSIONS

Active cancer, dementia, and high values for urea and RDW at admission are predictors of one-year mortality in patients hospitalized for HF. These variables are readily available at admission and can support the clinical management of HF patients.

A wearable device for at-home obstructive sleep apnea assessment: State-of-the-art and research challenges

In the last 3 years, almost all medical resources have been reserved for the screening and treatment of patients with coronavirus disease (COVID-19). Due to a shortage of medical staff and equipment, diagnosing sleep disorders, such as obstructive sleep apnea (OSA), has become more difficult than ever. In addition to being diagnosed using polysomnography at a hospital, people seem to pay more attention to alternative at-home OSA detection solutions. This study aims to review state-of-the-art assessment techniques for out-of-center detection of the main characteristics of OSA, such as sleep, cardiovascular function, oxygen balance and consumption, sleep position, breathing effort, respiratory function, and audio, as well as recent progress in the implementation of data acquisition and processing and machine learning techniques that support early detection of severe OSA levels.

Obstructive sleep apnoea-hypopnoea syndrome: state of the art

Obstructive sleep apnoea-hypopnoea syndrome (OSAHS) is an extremely common sleep-related breathing disorder (SRBD) characterised by complete or partial collapse of the upper airways. These nocturnal phenomena cause high-frequency hypoxemic desaturations (or intermittent hypoxia, IH) during sleep and alterations in gas exchange. The result of IH is the development or worsening of cerebro-cardio-vascular, metabolic and other diseases, which cause a high risk of death. Hence, OSAHS is a multifactorial disease affecting several organs and systems and presenting with various clinical manifestations involving different medical branches. Although it has been estimated that about one billion individuals worldwide are affected by OSAHS, this SRBD remains underestimated also due to misinformation regarding both patients and physicians. Therefore, this review aims to provide information on the main symptoms and risk factors for the detection of individuals at risk of OSAHS, as well as to present the diagnostic investigations to be performed and the different therapeutic approaches. The scientific evidence reported suggest that OSAHS is an extremely common and complex disorder that has a large impact on the health and quality of life of individuals, as well as on healthcare expenditure. Moreover, given its multifactorial nature, the design and implementation of diagnostic and therapeutic programmes through a multidisciplinary approach are necessary for a tailor-made therapy for each patient.

Eating habit of adding salt to foods and incident sleep apnea: a prospective cohort study

BACKGROUND

Previous studies have revealed that sodium-restricted diet intervention significantly decreased apnea frequency among patients with sleep apnea. However, the longitudinal association between the habit of adding salt to foods and sleep apnea in general populations is uncertain.

METHODS

The UK Biobank cohort study includes more than 500,000 participants aged 40 to 69 across the United Kingdom from 2006 to 2010. The frequency of adding salt to foods was collected through a touch screen questionnaire. Incident sleep apnea was ascertained by hospital inpatient records, death registries, primary care, and self-reported diagnosis. The association between the habit of adding salt to foods and incident sleep apnea was estimated using Cox proportional hazard regression models.

RESULTS

Among the 488,196 participants (mean age 56.5 years; 55.0% female) in this study. During a median follow-up of 12.3 years, 6394 sleep apnea events occurred. Compared to participants who never/rarely added salt to foods, those who sometimes, usually, and always added salt to foods had an 11% (hazard ratio [HR] 1.11, 95% confidence interval [CI]: 1.04 to 1.17), 15% (HR 1.15, 95% CI: 1.07 to 1.24), and 24% (HR 1.24, 95% CI: 1.12 to 1.37) higher risk for incident sleep apnea, respectively.

CONCLUSIONS

In this large prospective study, the habit of adding salt to foods was associated with a higher risk of incident sleep apnea. The findings support the benefits of a salt reduction program in preventing sleep apnea.

Prospective study of sleep duration, snoring and risk of heart failure

OBJECTIVE

To investigate whether nighttime sleep duration and snoring status were associated with incident heart failure (HF).

METHODS

A prospective study was conducted based on Kailuan cohort including 93 613 adults free of pre-existing cardiovascular diseases. Sleep duration and snoring status were assessed by self-reported questionnaire. Incident HF cases were ascertained by medical records. Cox proportional hazards model was applied to calculate the HR and 95% CI of risk of developing HF. Mediation analysis was used to understand whether hypertension and diabetes mediated the association between sleep duration, snoring and HF. Data analysis was performed from 1 June 2021 to 1 June 2022.

RESULTS

During a median follow-up of 8.8 years, we documented 1343 incident HF cases. Relative to sleep duration of 7.0-7.9 hour/night, short sleep duration was associated with higher risk of developing HF: adjusted HR was 1.24 (95% CI 1.01 to 1.55) for <6 hours/night and 1.29 (95% CI 1.06 to 1.57) for 6.0-6.9 hours/night, after adjustment for potential confounders such as age, sex, smoking, hypertension and diabetes. A similar 20%-30% higher risk of incident HF was found in individuals reporting occasional or frequent snoring relative to never/rare snorers: adjusted HR was 1.32 for occasional snoring (95% CI 1.14 to 1.52) and 1.24 (95% CI 1.06 to 1.46) for frequent snoring. Presence of diabetes significantly mediated the association between both short sleep duration and snoring and HF risk and hypertension significantly mediated the snoring-HF relationship.

CONCLUSION

Short sleep duration and snoring were associated with high risk of HF.

Association of obstructive sleep apnea with endothelial function and heart remodeling in hypertension: A cross-sectional study

BACKGROUND

This study aims to analyze the association of obstructive sleep apnea (OSA) with endothelial function and heart structure in patients with hypertension and lay a clinical foundation for preventing and treating endothelial dysfunction and heart remodeling in patients with hypertension.

METHODS

A cross-sectional study design was adopted in this study. From April 2020 to April 2021, 143 patients with hypertension were included and classified into two groups according to the severity of OSA: 81 patients with hypertension without OSA [apnea-hypopnea index (AHI) < 5 events/hour] serving as the control group; 62 patients with hypertension with moderate-severe OSA (AHI ≥ 15 events/hour) serving as the OSA group. The endothelial function and heart structure were assessed by flow-mediated vasodilation (FMD) and transthoracic echocardiography. Logistic regression analyses were conducted to identify factors associated with endothelial dysfunction and heart remodeling.

RESULTS

Compared with the control group, patients with OSA had significantly greater interventricular septal thickness (IVST) and left ventricular posterior wall thickness (LVPWT) (P < 0.05), and FMD exhibited a significant decrease (P < 0.05). Logistic regression analyses demonstrated that gender and AHI were associated with FMD (P < 0.05), and FMD was associated with LVMI (P < 0.05).

CONCLUSIONS

OSA was associated with endothelial dysfunction and heart remodeling in patients with hypertension. Endothelial dysfunction may be crucial for the development of heart remodeling in patients with hypertension with OSA.

Therapeutic Efficacy of Shexiang Baoxin Pill Combined with Exercise in Patients with Heart Failure with Preserved Ejection Fraction: A Single-Center, Double-Blind, Randomized Controlled Trial

OBJECTIVE

To evaluate the therapeutic efficacy of Shexiang Baoxin Pill combined with exercise in heart failure patients with preserved ejection fraction (HFpEF).

METHODS

Sixty patients with HFpEF were randomly divided into group A (n=20), receiving Shexiang Baoxin Pill combined with home-based exercise training based on conventional drugs for 12 weeks; group B (n=20), receiving conventional drugs combined with home-based exercise training for 12 weeks; and group C (n=20), receiving conventional drug treatment only. Peak oxygen uptake (peakVO₂), anaerobic threshold (AT), 6-min walking test (6MWT), Pittsburgh Sleep Quality Index (PSQI), and SF-36 questionnaire (SF-36) results before and after treatment were compared among groups.

RESULTS

After the 12-week intervention, patients in group C showed significant declines in peakVO₂, AT, 6MWT, PSQI, and SF-36 compared with pre-treatment (P<0.01), while groups A and B both showed significant improvements in peakVO₂, AT, 6MWT, PSQI, and SF-36 results compared with pre-treatment (P<0.01). Compared with group C, patients in groups A and B showed significant improvements in peakVO₂, AT, 6MWT, PSQI, and SF-36 (P<0.01). In addition, patients in group A showed more significant improvements in physical function, role-physical, vitality, and mental health scores on the SF-36 questionnaire, and PSQI scores than those in group B (P<0.01).

CONCLUSIONS

Exercise training improved exercise tolerance, sleep quality and quality of life (QoL) in patients with HFpEF. Notably, Shexiang Baoxin Pill played an active role in sleep quality and QoL of patients with HFpEF. (The trial was registered in the Chinese Clinical Trial Registry (No. ChiCTR2100054322)).

Linking knowledge with attitude: a cross-sectional study of public knowledge and attitude towards sleep disturbances and dementia

OBJECTIVES

Sleep disturbances increase the risk of dementia; however, there is insufficient information regarding this. We aimed to investigate public knowledge on the relationship between sleep disturbances and dementia, as well as attitudes towards improving sleep quality and obtaining knowledge on dementia.

DESIGN AND SETTING

A cross-sectional web-based questionnaire was administered between May and October 2019.

PARTICIPANTS

All participants provided informed consent and were able to respond to the survey.

PRIMARY OUTCOMES

Factors associated with the knowledge that sleep disturbances are risk factors for dementia and proportions of individuals with this knowledge; attitudes towards improving sleep quality and obtaining knowledge about dementia.

RESULTS

Of the 3329 eligible samples, 72.57% correctly recognised that sleep disturbances increased the risk of dementia. In total, 92.97% of participants were willing to take at least one measure to improve sleep quality, and the percentages of those adopting these measures are as follows: 78.73% would lead a regular life, 67.88% would engage in strengthening exercise, 28.84% would undergo psychotherapy and 19.41% would take medication. The awareness regarding sleep disturbances increasing the risk of dementia was the only factor associated with the willingness to improve sleep quality in all four categories of measures. Almost all participants (95.25%) were willing to take at least one measure to acquire knowledge about dementia, with the following participants displaying higher willingness to obtain knowledge about dementia: female, had contact with dementia and considered sleep disturbances to increase the risk of dementia.

CONCLUSIONS

Our findings indicate an association between people's knowledge and attitudes, suggesting the importance of disseminating knowledge about sleep disturbances and dementia to achieve dementia prevention in future.

Hypertension treatment in patients with sleep apnea from the European Sleep Apnea Database (ESADA) cohort - towards precision medicine

We recruited 5,970 hypertensive patients with obstructive sleep apnea (OSA) on current antihypertensive treatment from the European Sleep Apnea Database (ESADA) cohort. The group was subdivided into those receiving monotherapy (n = 3,594) and those receiving dual combined therapy (n = 2,376). We studied how major OSA confounders like age, gender, and body mass index as well as the degree of sleep apnea modified office systolic and diastolic blood pressure. Beta-blockers alone or in combination with a diuretic were compared with other antihypertensive drug classes. Monotherapy with beta-blocker was associated with lower systolic blood pressure, particularly in non-obese middle-aged males with hypertension. Conversely, the combination of a beta-blocker and a diuretic was associated with lower systolic and diastolic blood pressure in hypertensive patients with moderate-severe OSA. Systolic blood pressure was better controlled in female patients using this combined treatment. Our cross-sectional data suggest that specific clinical characteristics and type of antihypertensive medication influence the degree of blood pressure control in hypertensive OSA patients. Controlled trials are warranted.

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 Sacubitril/Valsartan on surfactant binding proteins, central sleep apneas, lung function tests and heart failure biomarkers: Hemodynamic or pleiotropism?

Purpose

Little is known about the mechanism underlying Sacubitril/Valsartan effects in patients with heart failure (HFrEF). Aim of the study is to assess hemodynamic vs. non-hemodynamic Sacubitril/Valsartan effects by analyzing several biological and functional parameters.

Methods

Seventy-nine patients (86% males, age 66 ± 10 years) were enrolled. At baseline and 6 months after reaching the maximum Sacubitril/Valsartan tolerated dose, we assessed biomarkers, transthoracic echocardiography, polysomnography, spirometry, and carbon monoxide diffusing capacity of the lung (DLCO).

Results

Mean follow-up was 8.7 ± 1.4 months with 83% of patients reaching Sacubitril/Valsartan maximum dose (97/103 mg b.i.d). Significant improvements were observed in cardiac performance and biomarkers: left ventricular ejection fraction increased (31 ± 5 vs. 37 ± 9 %; p &lt; 0.001), end-diastolic and end-systolic volumes decreased; NT-proBNP decreased (1,196 [IQR 648–2891] vs. 958 [IQR 424-1,663] pg/ml; p &lt; 0.001) in parallel with interleukin ST-2 (28.4 [IQR 19.4–36.6] vs. 20.4 [IQR 15.1–29.2] ng/ml; p &lt; 0.001) and circulating surfactant binding proteins (proSP-B: 58.43 [IQR 40.42–84.23] vs. 50.36 [IQR 37.16–69.54] AU; p = 0.014 and SP-D: 102.17 [IQR 62.85–175.34] vs. 77.64 [IQR 53.55-144.70] AU; p &lt; 0.001). Forced expiratory volume in 1 second and forced vital capacity improved. DLCO increased in the patients' subgroup (n = 39) with impaired baseline values (from 65.3 ± 10.8 to 70.3 ± 15.9 %predicted; p = 0.013). We also observed a significant reduction in central sleep apneas (CSA).

Conclusion

Sacubitril/Valsartan effects share a double pathway: hemodynamic and systemic. The first is evidenced by NT-proBNP, proSP-B, lung mechanics, and CSA improvement. The latter is confirmed by an amelioration of DLCO, ST-2, SP-D as well as by reverse remodeling echocardiographic parameters.

Aberrant amplitude of low-frequency fluctuations in different frequency bands and changes after one-night positive airway pressure treatment in severe obstructive sleep apnea

Objective

This study was aimed to investigate the characteristics of the amplitude of low-frequency fluctuation (ALFF) at specific frequencies in severe obstructive sleep apnea (OSA) patients. A comparison was made between pre-CPAP treatment and one night after continuous positive airway pressure (CPAP) treatment.

Methods

30 severe OSA patients and 19 healthy controls (HC) were recruited. The ALFF method was used to assess the local features of spontaneous brain activity and calculated at different bands (slow-5 and slow-4). A correlation analysis was performed to evaluate the relationship between the changes of the ALFF and polysomnography data.

Results

Compared with HC, in slow-5 frequency band, OSA patients showed significantly decreased ALFF in the left inferior temporal gyrus, and significantly increased ALFF in the left middle frontal gyrus, left inferior frontal gyrus, triangular part, right superior frontal gyrus, dorsolateral and right middle temporal gyrus. In slow-4 frequency, there was significantly decreased ALFF in the right inferior temporal gyrus, and significantly increased ALFF in the left precuneus, right posterior cingulate gyrus and right median cingulate besides the slow-5 difference band showed. Compared with pre-CPAP, we found that after CPAP treatment, ALFF signals in the left insula in slow-5 and left caudate in slow-4 increased, but the calcarine in slow-4 significantly reduced. Correlation analysis showed that the left angular slow-4 band change was positively correlated with the slow wave sleep change (r = 0.4933, p = 0.0056). The left cerebellum 6 slow-5 band change was positively correlated with the duration of the REM sleep change (r = 0.4563, p = 0.0113), and the left cerebellum 6 slow-4 band change was also positively correlated with the mean blood oxygen change in the REM (r = 0.4591, p = 0.0107) and NREM sleep (r = 0.4492, p = 0.0128).

Conclusion

We found that the use of slow-4 was more specific in OSA studies. These results suggested that the severe OSA patients have frequency-related abnormal spontaneous neural activity, which may contribute to a better understanding of the pathological basis of OSA-related diseases and provide a potential therapeutic target for OSA patients.

The Prognostic Role of Polysomnography Parameters in Heart Failure Patients with Previous Decompensation

Background: Sleep-disordered breathing (SDB) is a widespread comorbidity in patients with chronic heart failure (HF) and may have a deleterious effect on the pathogenesis of HF. We aimed to evaluate the prognostic role of polysomnography parameters in HF patients with previous decompensation. Methods: 123 patients were included in the prospective cohort study. In addition to the standard examination, all patients underwent polysomnography (PSG). Results: The Kaplan−Meier analysis showed the incidence of the combined endpoint differs between LVEF categories ≤25.5% vs. >25.5% (χ2 = 9.6, log rank p = 0.002), NTpro-BNP > 680 vs. ≤680 pg/mL (χ2 = 12.7, log rank p = 0.001), VO2peak categories <16 vs. ≥16 mL/min/kg (χ2 = 14.2, log rank p = 0.001), VE/VCO2 slope ≥38.5 vs. <38.5 (χ2 = 14.5, log rank p = 0.001), wake after sleep onset >40 min vs. ≤40 min (χ2 = 9.7, log rank p = 0.03), and sleep stage 2 (S2) <44% vs. ≥44% (χ2 = 12.4, log rank p = 0.001). Conclusion: Among the PSG parameters, WASO > 40 min and S2 < 44% were associated with a combined endpoint in patients with previous decompensation of HF. Moreover, higher NT-proBNP and VE/VCO2 slope, lower LVEF, and VO2peak were also independent factors of a poor prognosis.

Medullary astrocytes mediate irregular breathing patterns generation in chronic heart failure through purinergic P2X7 receptor signalling

Background

Breathing disorders (BD) (apnoeas/hypopneas, periodic breathing) are highly prevalent in chronic heart failure (CHF) and are associated with altered central respiratory control. Ample evidence identifies the retrotrapezoid nucleus (RTN) as an important chemosensitivity region for ventilatory control and generation of BD in CHF, however little is known about the cellular mechanisms underlying the RTN/BD relationship. Within the RTN, astrocyte‐mediated purinergic signalling modulates respiration, but the potential contribution of RTN astrocytes to BD in CHF has not been explored.

Methods

Selective neuron and/or astrocyte-targeted interventions using either optogenetic and chemogenetic manipulations in the RTN of CHF rats were used to unveil the contribution of the RTN on the development/maintenance of BD, the role played by astrocytes in BD and the molecular mechanism underpinning these alterations.

Findings

We showed that episodic photo-stimulation of RTN neurons triggered BD in healthy rats, and that RTN neurons ablation in CHF animals eliminates BD. Also, we found a reduction in astrocytes activity and ATP bioavailability within the RTN of CHF rats, and that chemogenetic restoration of normal RTN astrocyte activity and ATP levels improved breathing regularity in CHF. Importantly, P"X/ P2X7 receptor (P2X7r) expression was reduced in RTN astrocytes from CHF rats and viral vector-mediated delivery of human P2X7 P2X7r into astrocytes increases ATP bioavailability and abolished BD.

Interpretation

Our results support that RTN astrocytes play a pivotal role on BD generation and maintenance in the setting CHF by a mechanism encompassing P2X7r signalling.

Funding

This study was funded by the National Research and Development Agency of Chile (ANID).

Endocrine and Metabolic Illnesses in Young Adults with Prader-Willi Syndrome

Prader−Willi syndrome (PWS) is a rare genetic disorder characterized by an insatiable appetite that leads to morbid obesity. Previous studies reported health problems in adults with PWS. However, studies on younger adults are lacking, and there are no specific studies of endocrine and metabolic illness in this age group. We performed a retrospective cohort study of 68 individuals with PWS aged 19 to 34 years at Samsung Medical Center. The prevalence of endocrine and metabolic illnesses were compared with those in an age-, sex-, and BMI-matched healthy control group. Young adults with PWS had a higher prevalence of metabolic syndrome (35.3% vs. 4.4%), type 2 diabetes mellitus (50.0% vs. 5.4%), hypertension (30.8% vs. 16.1%), dyslipidemia (38.2% vs. 14.7%), decreased bone density (26.4% vs. 0.9%), and sleep apnea (32.3% vs. 4.4%) than controls (all p < 0.05). The PWS group that maintained recombinant human growth (rhGH) treatment in adulthood had a lower probability of having a BMI ≥ 30 at the last follow-up (odds ratio = 0.106 (0.012−0.948), p = 0.045). Endocrine and metabolic illnesses in individuals with PWS may have already started in the early teens; therefore, appropriate screening and early intervention are important. Better understanding of the natural history of PWS and age-related complications will lead to better-quality medical care for individuals with PWS.

Effects of Sacubitril-Valsartan on Clinical, Echocardiographic, and Polygraphic Parameters in Patients Affected by Heart Failure With Reduced Ejection Fraction and Sleep Apnea

Background

Heart failure with reduced ejection fraction (HFrEF) is a clinical condition frequently diagnosed in clinical practice. In patients affected by HFrEF, sleep apnea (SA) can be detected among the most frequent comorbidities. Sacubitril–valsartan (sac/val) association has been proven to be effective in reducing disease progression and all-cause mortality in HFrEF patients. Sac/val treatment can potentially attenuate SA development via several pathophysiologic mechanisms, including improvement of global hemodynamics, reduction of extracellular fluid overload, and decrease of sympathetic neural activity.

Methods

We recruited 132 patients affected by HFrEF and SA, already under treatment with continuous positive airway pressure (CPAP), which was discontinued 24 h before the scheduled study timepoints. Physical examination, echocardiography, nocturnal cardio-respiratory monitoring, and laboratory tests were performed in each patient at baseline and after a 6-month treatment with sac/val.

Results

After 6 months, sac/val induced statistically significant changes in clinical, hemodynamic, biohumoral (NT-proBNP, serum electrolytes, creatinine, and uric acid), and echocardiographic parameters. In particular, cardiac index (CI), both atrial and ventricular volumes and global longitudinal strain (GLS) improved. Moreover, polysomnography, carried out during a temporary CPAP interruption, revealed a significant reduction in global apnea-hypopnea index (AHI) value (p < 0.0001), central AHI (p < 0.0001), obstructive AHI (p < 0.0001), oxygen desaturation index (ODI) (p < 0.0001), and percentage time of saturation below 90% (TC90) (p < 0.0001). The changes of CI, estimated glomerular filtration rate (eGFR), NT-proBNP, and tricuspid annular plane excursion (TAPSE) contributed to 23.6, 7.6, 7.3, and 4.8% of AHI variability, respectively, and the whole model accounted for a 43.3% of AHI variation.

Conclusions

Our results suggest that treatment with sac/val is able to significantly improve the cardiorespiratory performance of patients with HFrEF and SA, integrating the positive impact of CPAP. Thus, both CPAP and sac/val therapy may synergistically contribute to lower the risks of both cardiac and pulmonary complications in HFrEF patients with SA.

Potential Role of the Retrotrapezoid Nucleus in Mediating Cardio-Respiratory Dysfunction in Heart Failure With Preserved Ejection Fraction

A strong association between chemoreflex hypersensitivity, disordered breathing, and elevated sympathetic activity has been shown in experimental and human heart failure (HF). The contribution of chemoreflex hypersensitivity in HF pathophysiology is incompletely understood. There is ample evidence that increased peripheral chemoreflex drive in HF with reduced ejection fraction (HFrEF; EF<40%) leads to pathophysiological changes in autonomic and cardio-respiratory control, but less is known about the neural mechanisms mediating cardio-respiratory disturbances in HF with preserved EF (HFpEF; EF>50%). Importantly, it has been shown that activation of the central chemoreflex worsens autonomic dysfunction in experimental HFpEF, an effect mediated in part by the activation of C1 catecholaminergic neurons neighboring the retrotrapezoid nucleus (RTN), an important region for central chemoreflex control of respiratory and autonomic function. Accordingly, the main purpose of this brief review is to discuss the possible role played by activation of central chemoreflex pathways on autonomic function and its potential role in precipitating disordered breathing in HFpEF. Improving understanding of the contribution of the central chemoreflex to the pathophysiology of HFpEF may help in development of novel interventions intended to improve cardio-respiratory outcomes in HFpEF.

Obstructive Sleep Apnea Impacts Cardiac Function in Dilated Cardiomyopathy Patients Through Circulating Exosomes

Background

Obstructive sleep apnea (OSA) is common and independently associated with heart failure. This study aimed to investigate the impact of OSA on heart function in patients with dilated cardiomyopathy (DCM) as well as the possible mechanism related to exosomes regulated autophagy.

Methods and Results

A total of 126 patients with DCM who underwent sleep evaluations were analyzed retrospectively. Cardiomyocytes were treated with exosomes isolated from untreated OSA patients and healthy controls. Fibrotic and hypertrophic markers were evaluated, and Akt/mTOR pathway-mediated autophagy was investigated. DCM patients with severe OSA had larger right ventricular end-diastolic diameter (RVEDd) and right atrial diameter (RAD) and increased N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels than DCM patients without OSA. Moreover, NT-proBNP and diabetes mellitus were independently correlated with the apnea-hypopnea index in multiple linear regression analysis. Treatment with OSA-derived exosomes significantly increased Col1A1, ANP, and BNP protein expression and decreased the expression of the autophagy markers LC3B II/I and beclin1. Rapamycin treatment significantly increased the decreased autophagy markers and attenuated the increased expression of Col1A1, ANP and BNP induced by OSA-derived exosomes.

Conclusion

The severity of OSA is significantly associated with cardiac injury and remodeling. The underlying mechanism may be related to changed autophagy levels, which are regulated by circulating exosomes via the Akt/mTOR signaling pathway. This study may provide a new clue for the treatment of heart failure with OSA.

Sleep Quality, Sleep Duration, and the Risk of Adverse Clinical Outcomes in Patients With Myocardial Infarction With Non-obstructive Coronary Arteries

Background

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is a heterogeneous entity with varying underlying etiologies and occurs in ~5–10% of patients with acute myocardial infarction. Sleep disorders and short sleep duration are common phenomena experienced by patients with coronary heart disease and are associated with poor clinical outcomes. However, the association between sleep quality, sleep duration, and the MINOCA prognosis is less clear.

Methods

We performed a prospective observational study of 607 patients with MINOCA between February 2016 and June 2018. The mean follow-up period was 3.9 years. Sleep quality and sleep duration were measured by the Chinese version of the Pittsburgh Sleep Quality Index. The primary endpoint was all-cause mortality, and the secondary endpoint was major adverse cardiovascular events (MACE), defined as a composite of cardiovascular death, non-fatal myocardial infarction, stroke and heart failure hospitalization.

Results

During the follow-up period, all-cause death occurred in 69 participants and 105 participants developed MACE. The Kaplan–Meier survival analysis demonstrated a significant association between poor sleep quality and all-cause mortality (log-rank P = 0.005) and MACE (log-rank P = 0.004). Multivariable Cox regression model indicated that poor sleep quality was an independent predictor of all-cause mortality as well as MACE [adjusted hazard ratio (HR) = 1.649; 95% confidence interval (CI), 1.124–2.790; P &lt; 0.001; and adjusted HR = 1.432; 95% CI, 1.043–2.004; P = 0.003, respectively]. For sleep duration, short sleep duration (&lt;6 h/d) was significantly associated with an increased risk of all-cause mortality and MACE (adjusted HR = 1.326; 95% CI, 1.103–1.812; P = 0.004; and adjusted HR = 1.443; 95% CI, 1.145–1.877; P &lt; 0.001, respectively), whereas long sleep duration was not (&gt;8 h/d). A poorer sleep profile (including poor sleep quality and short sleep duration) was associated with a 149.4% increased risk of death (HR = 2.494; 95% CI, 1.754–4.562; P &lt; 0.001) and a 96.7% increased risk of MACE (HR = 1.967; 95% CI, 1.442–3.639; P &lt; 0.001) than those with neither.

Conclusion

Sleep disorders were common among Chinese patients with MINOCA. Poor sleep quality and short sleep duration were independently associated with an increased risk of all-cause mortality and MACE in the MINOCA population. Meanwhile, a poor sleep profile has an additive effect with regard to cardiovascular risks; in these populations, efforts should be made to improve both sleep quality and sleep duration for secondary cardiovascular prevention.

Clinical Trial Registration

http://www.chictr.org.cn, identifier: ChiCTR2000040701.

Sleep-disordered breathing is independently associated with elevated natriuretic peptide levels in patients with cardiovascular diseases

Sleep disorders and sleep duration have attracted considerable attention as potential modifiable risk factors for the development and progression of heart failure (HF). However, whether these sleep behaviors could aggravate the underlying cardiac condition remains ambiguous. We evaluated the associations between the levels of plasma B-type natriuretic peptide (BNP) and sleep-disordered breathing (SDB), sleep quality and quantity, or daytime sleepiness in cardiovascular diseases (CVD) patients. A total of 1717 consecutive patients with CVD [median age, 66 years (55-74 years); female, 27.5%] were enrolled. SDB was screened by nocturnal pulse oximetry; sleep quality and quantity were determined by Pittsburg Sleep Quality Index, and daytime sleepiness was examined by Epworth Sleepiness Scale. The median plasma BNP level was 54.9 pg/ml (23.5-146.4 pg/ml). Multiple regression analyses showed that the BNP level in the highest quintile (BNP > 181.8 pg/ml) was associated with SDB (severe: OR, 5.88; 95% CI 3.17-10.88; moderate: OR, 3.62; 95% CI 2.17-6.02; mild: OR, 2.22: 95% CI 1.42-3.47). There were no significant associations between other sleep parameters and higher BNP levels. The relationship between SDB and BNP levels was unchanged regardless of the previous history of symptomatic HF. SDB was independently associated with the elevated plasma BNP level in patients with a variety of CVD.

Serum Serotonin as a Biomarker of the Efficacy of PAP-Therapy in Sleep Apnea Syndrome

Serum serotonin levels were determined by HPLC in 30 patients with diagnosed obstructive sleep apnea syndrome before and after 3-month course of PAP-therapy and in 14 subjects without obstructive sleep apnea symptoms. It was found that elimination of hypoxic conditions was associated with an increase in serotonin level. The results demonstrate the effectiveness of PAP-therapy during sleep and allow assessing the role of serotonin as a potential biomarker of intermittent hypoxia during sleep.

Sleep Apnea and Serum Serotonin Level Pre- and Post-PAP Therapy: A Preliminary Study

Introduction

The high prevalence of obstructive sleep apnea (OSA), which impairs quality of life for numerous patients and leads to various OSA complications, has contributed to the continued interest in this disorder. The role of serotonin (5-HT) in many physiological processes, studies on its connection with the circadian system, and relationship to changes in sleep architecture are insufficient to assess the interaction of this neurotransmitter with nocturnal hypoxia. The aim of this study was to determine changes in sleep patterns and serum serotonin levels before and after positive airway pressure (PAP) therapy in patients with OSA.

Methods

The study involved 30 OSA patients (27 men and 3 women) who were treated with PAP for 3 months. Polysomnography using the GRASS TELEFACTOR (USA) and blood collection were conducted before and after PAP courses. Determination of serum serotonin was performed by high-performance liquid chromatography (HPLC). PAP therapy was performed using an automatic Prisma 20A (Germany) continuous positive airway pressure (CPAP) device.

Results

The use of PAP for 3 months revealed a significant improvement as measured by sleep data and serotonin levels (before: apnea index [AI] 17.2 eV/h, after: 2.4 eV/h p = 0.001; SpO₂ < 90% − 45.7 min vs. 6.2 min p = 0.001; serotonin 20.3 ng/mL vs. 26.03 ng/mL p = 0.036].

Conclusion

Our results demonstrate an improvement in sleep patterns. There was an increase in serum serotonin levels in OSA patients following PAP therapy, which could be an effect of intermittent hypoxia decline, and could be used as criteria for the effectiveness of PAP and an improvement in sleep quality.

MKRN1 Ubiquitylates p21 to Protect against Intermittent Hypoxia-Induced Myocardial Apoptosis

Although chronic intermittent hypoxia- (IH-) induced myocardial apoptosis is an established pathophysiological process resulting in a poor prognosis for patients with obstructive sleep apnea syndrome, its underlying mechanism remains unclear. This study is aimed at exploring the role of makorin ring finger protein 1 (MKRN1) in IH-induced myocardial apoptosis and elucidating its molecular activity. First, the GSE2271 dataset was downloaded from the Gene Expression Omnibus database to identify the differentially expressed genes. Then, an SD rat model of IH, together with rat cardiomyocyte H9C2 and human cardiomyocyte AC16 IH models, was constructed. TUNEL, Western blot, and immunohistochemistry assays were used to detect cell apoptosis. Dihydroethidium staining was conducted to analyze the concentration of reactive oxygen species. In addition, RT-qPCR, Western blot, and immunohistochemistry were performed to measure the expression levels of MKRN1 and p21. The direct interaction between MKRN1 and p21 was determined using coimmunoprecipitation and ubiquitination analysis. MKRN1 expression was found to be downregulated in IH rat myocardial tissues as well as in H9C2 and AC16 cells. Upregulated expression of MKRN1 in H9C2 and AC16 cells alleviated the IH-induced reactive oxygen species production and cell apoptosis. Mechanistically, MKRN1 promoted p21 protein ubiquitination and the proteasome pathway degradation to negatively regulate p21 expression. Thus, MKRN1 regulates p21 ubiquitination to prevent IH-induced myocardial apoptosis.

[Objective sleep characteristics and risk factors for sleep apnea in heart failure patients with different left ventricular ejection fraction]

OBJECTIVE

To investigate the objective sleep characteristics and the independent risk factors for sleep apnea in heart failure (HF) patients with different left ventricular ejection fractions (LVEF).

METHODS

A total of 107 patients with chronic HF hospitalized in the Department of Cardiology of our hospital from April, 2019 to October, 2020 were included in this study. According to the LVEF measured by echocardiography, the patients were divided into reduced ejection fraction (HFrEF) group (n=35), mid-range ejection fraction (HFmrEF) group (n=21), and preserved ejection fraction (HFpEF) group (n=51). The baseline demographic and clinical characteristics of the patients were recorded. To assess the objective sleep characteristics, whole night polysomnography was scheduled for all the patients. Spearman correlation and multinomial logistic regression analyses were used to explore the factors affecting objective sleep characteristics.

RESULTS

The patients in HFpEF group had significantly lower proportion of non-rapid eye movement sleep stage 1, apnea hypopnea index (AHI), and central sleep apnea (CSA) than those in HFrEF group (all P < 0.05). The baseline demographic data or sleep structures in HFmrEF group did not differ significantly from those in the other two groups. Spearman correlation analysis revealed significant correlations of the male sex, diuretics use, NT-proBNP, LVEF, and total cholesterol levels with the severity of AHI (all P < 0.05). After adjusting for potential confounders, multiple logistics regression analysis showed that age, drinking, and LVEF levels were independently associated with the severity of AHI (all P < 0.05).

CONCLUSION

Abnormal objective sleep architectures occur in all HF patients, manifested mainly by sleep apnea. The incidences of sleep apnea and CSA are lower in patients with HFpEF than in those with HFrEF. Age, drinking, and LVEF levels are independent risk factors for the occurrence and severity of sleep apnea.

Sleep Quality in Patients Undergoing Transcatheter Aortic Valve Implantation (TAVI)

The present study aimed to analyze sleep quality and quality of Life (QoL) in patients undergoing Transcatheter Aortic Valve Implantation (TAVI). It was conducted at the Interventional Cardiology Unit of the Department of Cardiac, Thoracic, Vascular Sciences and Public Health of the University of Padova on 27 adult patients who underwent TAVI via the transfemoral approach. Patients completed two validated instruments, i.e., the Pittsburgh Sleep Quality Index (PSQI) and the EuroQoL (EQ-5D-5L), on the day of discharge and one month after the hospital discharge. Twenty-seven patients were enrolled with a severe aortic stenosis diagnosis, treated with transfemoral TAVI procedure. The study population included seventeen poor sleepers and ten good sleepers with a median age of 81.92 years overall. The global PSQI evaluation revealed a small significant improvement at follow-up (p-value 0.007). Small positive changes were detected in the Self-care and Usual activity domains of the EQ-5D-5L and the EQ-VAS. No correlation was detected between EQ-5D-5L and sleep quality. The present study confirms the importance of sleep quality monitoring in patients who undergo TAVI procedure for aortic stenosis treatment.

Sleep Outcomes From AWAKE-HF: A Randomized Clinical Trial of Sacubitril/Valsartan vs Enalapril in Patients With Heart Failure and Reduced Ejection Fraction

BACKGROUND

Heart failure and sleep-disordered breathing have been increasingly recognized as co-occurring conditions. Their bidirectional relationship warrants investigation into whether heart failure therapy improves sleep and sleep-disordered breathing. We sought to explore the effect of treatment with sacubitril/valsartan on sleep-related endpoints from the AWAKE-HF study.

METHODS AND RESULTS

AWAKE-HF was a randomized, double-blind study conducted in 23 centers in the United States. Study participants with heart failure with reduced rejection fraction and New York Heart Association class II or III symptoms were randomly assigned to receive treatment with either sacubitril/valsartan or enalapril. All endpoints were assessed at baseline and after 8 weeks of treatment. Portable sleep-monitoring equipment was used to measure the apnea-hypopnea index, including obstructive and central events. Total sleep time, wake after sleep onset and sleep efficiency were exploratory measures assessed using wrist actigraphy.

THE RESULTS WERE AS FOLLOWS

140 patients received treatment in the double-blind phase (sacubitril/valsartan, n = 70; enalapril, n = 70). At baseline, 39% and 40% of patients randomly assigned to receive sacubitril/valsartan or enalapril, respectively, presented with undiagnosed, untreated, moderate-to-severe sleep-disordered breathing (≥ 15 events/h), and nearly all had obstructive sleep apnea. After 8 weeks of treatment, the mean 4% apnea-hypopnea index changed minimally from 16.3/h to 15.2/h in the sacubitril/valsartan group and from 16.8/h to 17.6/h in the enalapril group. Mean total sleep time was long at baseline and decreased only slightly in both treatment groups at week 8 (-14 and -11 minutes for sacubitril/valsartan and enalapril, respectively), with small changes in wake after sleep onset and sleep efficiency in both groups.

CONCLUSIONS

In a cohort of patients with heart failure with reduced rejection fraction who met prescribing guidelines for sacubitril/valsartan, one-third had undiagnosed moderate-to-severe obstructive sleep apnea. The addition of sacubitril/valsartan therapy did not significantly improve sleep-disordered breathing or sleep duration or efficiency. Patients who meet indications for treatment with sacubitril/valsartan should be evaluated for sleep-disordered breathing.

Effects of Transcatheter Mitral Valve Repair Using MitraClip® Device on Sleep Disordered Breathing in Patients with Mitral Valve Regurgitation

Sleep disordered breathing (SDB) is common among patients with valvular heart disease, and successful valve surgery could reduce SDB severity. However, data about the effects of transcatheter mitral valve repair on SDB are scarce. Therefore, mitral regurgitation (MR) patients undergoing MitraClip-placement were prospectively enrolled. Before MitraClip-placement, daytime sleepiness and sleep quality were assessed using the Epworth Sleepiness Scale (ESS) and Pittsburgh Sleep Quality Index (PSQI), respectively; and all patients underwent SDB screening using five-channel respiratory polygraphy. After 3-6 months, patients had a similar reassessment including: ESS, PSQI, and respiratory polygraphy. 67 patients were included (77 ± 8years). Despite normal sleepiness scores, 41 patients (61%) had SDB with apnea-hypopnea-index (AHI) ≥ 15 h before MitraClip-placement, of whom only three patients had known SDB previously. Compared to patients without SDB, patients with SDB had similar sleepiness scores but higher NT-proBNP values at baseline (4325 vs. 1520 pg/mL, p < 0.001). At follow-up, there were significant AHI improvements among patients with SDB (p = 0.013). However, there were no significant sleepiness score changes. In conclusion, the prevalence of SDB among MitraClip candidates is very high even in those without daytime sleepiness. MR patients with SDB have higher NT-proBNP values, which may reflect a worse prognosis. MitraClip-placement may improve the underlying SDB, which could be an additional benefit of the procedure.