Apneas of Heart Failure and Phenotype-Guided Treatments: Part One: OSA

Central sleep apnea and cardiovascular disease state-of-the-art

Central sleep apnea, a rare polysomnographic finding in the general population, is prevalent in certain cardiovascular conditions including systolic and diastolic left ventricular dysfunction, atrial fibrillation, coronary artery disease, carotid artery stenosis, stroke, and use of certain cardiac-related medications. Polysomnographic findings of central sleep apnea with adverse cardiovascular impacts include nocturnal hypoxemia and arousals, which can lead to increased sympathetic activity both at night and in the daytime. Among cardiovascular diseases, central sleep apnea is most prevalent in patients with left ventricular systolic dysfunction; a large study of more than 900 treated patients has shown a dose-dependent relationship between nocturnal desaturation and mortality. Multiple small randomized controlled trials have shown mitigation of sympathetic activity when central sleep apnea is treated with nocturnal oxygen, continuous positive airway pressure, and adaptive servoventilation. However, two early randomized controlled trials with positive airway pressure devices have shown either a neutral effect on survival or excess premature mortality in the active treatment arm, compared to untreated central sleep apnea. In contrast, the results of the most recent trial using an advanced adaptive servoventilation device showed improved quality of life and no signal for mortality suggesting that treatment of central sleep apnea was at least safe. In addition to positive airway pressure devices, multiple medications have been shown to improve central sleep apnea, but no long-term trials of pharmacologic therapy have been published. Currently, phrenic nerve stimulation is approved for the treatment of central sleep apnea, and the results of a randomized controlled trial showed significant improvement in sleep metrics and quality of life.

Rising cardiovascular mortality among obstructive sleep apnea patients: United States epidemiological trends (1999-2019)

BACKGROUND

Obstructive sleep apnea (OSA) prevalence has risen significantly, affecting millions globally and posing a major healthcare burden. OSA is strongly associated with cardiovascular diseases (CVD) such as heart failure, stroke, and ischemic heart disease. However, trends in CVD-related mortality among individuals with OSA remain underexplored.

OBJECTIVE

This study aims to assess the trends of OSA and CVD related mortality rates and variations in mortality based on demographics and regions in the US.

METHODS

Mortality data for adults aged ≥25 with OSA and CVD were extracted from the CDC WONDER database. Age-adjusted mortality rates (AAMRs) per 100,000 and annual percent change (APC) with 95 % confidence intervals (CIs) were calculated, stratified by year, sex, race/ethnicity, age, urbanization, and Census regions.

RESULTS

Between 1999 and 2019, 168,111 OSA-related CVD deaths were recorded. Overall AAMRs rose significantly, particularly for hypertensive disease (1999-2006 APC: 13.2 %, 95 % CI: 11.6-15.7). Men consistently had higher AAMRs than women, and Black individuals showed the highest racial disparities. AAMRs varied geographically, with the Midwest recording the highest rates and rural areas showing notable increases. States like Oregon and Montana had rates three times higher than New York and Massachusetts.

CONCLUSIONS

OSA-related CVD mortality has risen substantially, with marked disparities by sex, race, and region. These findings emphasize the need for targeted public health interventions to reduce mortality in high-risk groups.

Up-to-date advance in the relationship between obstructive sleep apnea and heart failure: a narrative review

PURPOSE

Obstructive sleep apnea (OSA) is recognized as an independent and significant risk factor for various cardiovascular and cerebrovascular conditions, including heart failure (HF). In this review, we explore the impact of OSA on HF, examine shared contributing factors and underlying pathophysiological mechanisms, and assess the treatment options for OSA and their potential therapeutic value in HF patients.

METHODS

Pubmed/MEDLINE were searched through September 2024 to explore the relationship between OSA and HF. The relevant papers included OSA and HF, risk factors of OSA and HF, and the prognosis and treatment of HF patients with OSA.

RESULTS

The results showed that OSA increased the risk of HF. OSA can exacerbate or contribute to the onset of HF in several ways. The application of continuous positive airway pressure (CPAP) and other treatments may benefit HF patients with OSA. Drug therapy has shown promise for treating OSA, extensive multi-center studies remain essential, particularly in patients with both OSA and HF.

CONCLUSION

OSA can exacerbate or contribute to the onset and recurrence of HF in several ways. Further studies should be carried out to explore effective treatments in patients with HF and OSA.

Renal Denervation in Heart Failure Treatment: Data for a Self-Fulfilling Prophecy

Renal denervation (RDN), a transcatheter renal sympathetic nerve ablation procedure, is a relatively novel established procedure for the treatment of hypertension, with it being recognized as a third option for hypertension management in the most recent European guidelines, together with pharmacotherapy, for achieving blood pressure targets. Given the relationship between both hypertension and sympathetic overdrive and the development of heart failure (HF), even studies at the dawn of research on RDN explored it as a treatment to overcome diuretic resistance in those patients. As it is now recognized that RDN does not only have organ-specific but also systemic effects, several investigators have aimed to delineate whether renal sympathetic denervation could alter the prognosis, symptoms, and adverse events of HF patients. Data are available in both HF patients with reduced and preserved ejection fraction. As the significance of neuromodulation is gaining grounds in the HF therapeutic arsenal, in this review, we aim to provide a rationale for using RDN in HF and an up-to-date overview of available data in both HF phenotypes, as well as discuss the future of neuromodulatory therapy in HF management.

Interactions of Obstructive Sleep Apnea With the Pathophysiology of Cardiovascular Disease, Part 1: JACC State-of-the-Art Review

The American Heart Association considers sleep health an essential component of cardiovascular health, and sleep is generally a time of cardiovascular quiescence, such that any deviation from normal sleep may be associated with adverse cardiovascular consequences. Many studies have shown that both impaired quantity and quality of sleep, particularly with obstructive sleep apnea (OSA) and comorbid sleep disorders, are associated with incident cardiometabolic consequences. OSA is associated with repetitive episodes of altered blood gases, arousals, large negative swings in intrathoracic pressures, and increased sympathetic activity. Recent studies show that OSA is also associated with altered gut microbiota, which could contribute to increased risk of cardiovascular disease. OSA has been associated with hypertension, atrial fibrillation, heart failure, coronary artery disease, stroke, and excess cardiovascular mortality. Association of OSA with chronic obstructive lung disease (overlap syndrome) and morbid obesity (obesity hypoventilation syndrome) increases the odds of mortality.

Effects of Positive Airway Pressure on Cardiorespiratory Fitness in Patients with Concomitant Obstructive Sleep Apnea and Cardiovascular Disease

Background and Objectives: Obstructive sleep apnea (OSA) is common in cardiovascular disease (CVD), although positive airway pressure (PAP) treatment has not been demonstrated to improve the cardiovascular outcome. The objective of this study is to investigate the impact of adherence to PAP therapy on cardiopulmonary exercise testing (CPET) performance in patients with concomitant OSA and CVD. Materials and Methods: This preliminary study involved symptomatic OSA patients requiring PAP treatment who had CVD. All subjects underwent polysomnography, echocardiography, and CPET at baseline. After 6 to 12 months of PAP treatment, CPET performance was re-assessed. The changes in CPET parameters before and after PAP treatment were compared between patients who were adherent to PAP and patients who were not adherent to PAP. Results: A total of 16 OSA patients with an apnea-hypopnea index of 32.0 ± 23.4 were enrolled. Patients were classified into the adherent (n = 9) and non-adherent (n = 7) groups with regard to PAP adherence. After 6 to 12 months of PAP treatment, the PAP-adherent group showed a greater increase in peak VO2 than the PAP-non-adherent group, but the difference between the two groups was not significant (p = 0.581). The decrease in ventilatory equivalent for the carbon dioxide slope (VE/VCO2) was significantly greater in the PAP-adherent group compared to the PAP-non-adherent group (p = 0.030). Conclusions: Adherence to PAP therapy for OSA is associated with an improvement in the VE/VCO2 slope, as an index of the ventilatory response to exercise, in patients with CVD. Screening for sleep apnea in CVD patients may be warranted, and strategies to optimize adherence to PAP in these patients are beneficial. Further evidence is needed to elucidate whether CPET could be routinely used to monitor treatment responses of OSA to PAP therapy in patients with CVD.

Sleep Apnea and Atrial Fibrillation: Clinical Features and Screening Diagnostic Options

INTRODUCTION

Obstructive sleep apnea (OSA) is associated with an increased risk of hypertension, coronary artery disease, heart failure (HF), and atrial fibrillation (AF).

MATERIALS AND METHODS

A total of 179 patients aged 34-81 years were included in the study. The median age was 63 years (interquartile range: 56-69 years). Of these patients, 105 (58.7%) were men, and 74 (41.3%) were women; there were cases of paroxysmal (n = 99), persistent (n = 64), and permanent AF (n = 16). All patients underwent investigations including respiratory sleep monitoring, echocardiography, and 24 h Holter electrocardiography monitoring. Statistical analyses were performed using IBM SPSS Statistics 26.0.

RESULTS

OSA was detected in 131 (73.2%) patients. In patients with OSA, paroxysmal AF was commonest (n = 65), followed by persistent AF (n = 51) and permanent AF (n = 15). The patients with sleep apnea had increased body mass index (33.6 kg/m2; p = 0.02), waist circumference (114 cm; p < 0.001), and neck circumference (42 cm; p < 0.001) values. HF (OR 2.9; 95% CI: 1.4-5.9; p = 0.004) and type 2 diabetes (OR 3.6; 95% CI: 1.5-8.3; p = 0.001) were more common in patients with AF and OSA. The STOP-BANG scale (AUC = 0.706 ± 0.044; 95% CI: 0.619-0.792; p < 0.001) and the Berlin questionnaire (AUC = 0.699 ± 0.044; 95% CI: 0.614-0.785) had a higher predictive ability for identifying sleep apnea.

CONCLUSIONS

Patients with AF demonstrate a high prevalence of OSA and an increased association with cardiovascular comorbidities. The STOP-BANG scale and the Berlin questionnaire can be used to screen for OSA in patients with AF.

Novel Approaches to Sleep Apnea in Heart Failure

Sleep apnea is a serious comorbid condition affecting patients with heart failure. Present in 50% to 75% of heart failure patients, it is often underrecognized, underdiagnosed, and undertreated. Patients with sleep apnea and heart failure are at increased risk of adverse cardiovascular events and sudden death. Treatment of sleep apnea has shown mixed results in reduction of adverse outcomes by sleep apnea type and intervention strategy. Evolving home-based technologies and device therapies present an exciting frontier for patients with sleep apnea and heart failure and an opportunity to improve outcomes. This article reviews novel approaches to sleep apnea in heart failure.

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.

Association between Obstructive Sleep Apnea and Heart Failure in Adults-A Systematic Review

BACKGROUND

Heart failure (HF) patients commonly experience obstructive sleep apnea (OSA), which may worsen their condition. We reviewed a diverse range of studies to investigate the prevalence of OSA in HF patients, the effects of positive airway pressure (PAP) treatment, and the potential impact of sodium-glucose cotransporter-2 inhibitors (SGLT2i) and sacubitril/valsartan on OSA outcomes.

METHODS

We analyzed case-control, observational studies, and randomized controlled trials. Prevalence rates, PAP treatment, and HF pharmacotherapy were assessed.

RESULTS

Numerous studies revealed a high prevalence of OSA in HF patients, particularly with preserved ejection fraction. PAP treatment consistently improved an apnea-hypopnea index, left ventricular ejection fraction, oxygen saturation, and overall quality of life. Emerging evidence suggests that SGLT2i and sacubitril/valsartan might influence OSA outcomes through weight loss, improved metabolic profiles, and potential direct effects on upper airway muscles.

CONCLUSIONS

The complex interplay between OSA and HF necessitates a multifaceted approach. PAP treatment has shown promising results in improving OSA symptoms and HF parameters. Additionally, recent investigations into the effects of HF pharmacotherapy on OSA suggest their potential as adjunctive therapy. This review provides insights for clinicians and researchers, highlighting the importance of addressing OSA and HF in patient management strategies.

Renin-angiotensin system activation: may it increase frequency of obstructive sleep apnea in patients with autosomal dominant polycystic kidney disease?

PURPOSE

Renin-angiotensin system (RAS) hyperactivity is a common entity in both autosomal dominant polycystic kidney disease (ADPKD) and obstructive sleep apnea (OSA). We aimed to investigate the frequency of OSA in adults with ADPKD either with stages 3-4 or stages 1-2 chronic kidney disease (CKD) and evaluate the effect of RAS blockade on OSA in these patients.

METHODS

This is a comparative, prospective, two-center clinical study. Eligible patients with ADPKD were enrolled in a polysomnography (PSG) study. Presence of OSA in patients with ADPKD was compared with individuals who underwent polisomnography study due to OSA symptoms. A subgroup analysis was performed in terms of the presence of OSA in ADPKD with eGFR values lower or higher than 60 ml/min/1.73 m2 (stages 3-4 and stages 1-2 CKD, respectively).

RESULTS

Frequency of OSA (65%) was higher than in the general population and similar between the two groups (p = 0.367). Patients with ADPKD and eGFR ≥ 60 ml/min/1.73 m2 presented a similar frequency of OSA to the control group (p = 0.759). However, OSA was significantly more frequent in ADPKD with eGFR < 60 ml/min/1.73 m2 (p = 0.018). Subgroup analysis revealed that presence of OSA also was significantly higher in ADPKD with lower eGFR levels (eGFR < 60 ml/min/1.73 m2 and eGFR > 60 ml/min/1.73 m2) 14/17 (82%) and 12/23 (52%), respectively (p: 0.048).

CONCLUSION

As kidney disease progresses, uremia and related factors of renal failure rather than RAS activation seem to play a more important role for the development of OSA in patients with ADPKD.

Severe sleep apnea as a predictor of failure to respond to cardiac resynchronization therapy

BACKGROUND

The response to cardiac resynchronization therapy (CRT) is suboptimal in one-third of patients.

OBJECTIVES

The study aimed to evaluate the impact of sleep-disordered breathing (SDB) on the CRT-induced left ventricular (LV) reverse remodeling and response for CRT in patients with ischemic congestive heart failure (CHF).

METHODS

A total of 37 patients aged 65.43 years (SD 6.05), seven of whom were females, were treated with CRT according to class I European Society of Cardiology recommendations. Clinical evaluation, polysomnography, and contrast echocardiography were performed twice during the six-month follow-up (6M-FU) to assess the effect of CRT.

RESULTS

In 33 patients (89.1%), sleep-disordered breathing (SDB), predominantly central sleep apnea (70.3%) was observed. This include nine patients (24.3%) with an apnea-hypopnea index (AHI) of >30 events/hour. During the 6M-FU, 16 patients (47.1%) responded to CRT by reducing LV end-systolic volume index (LVESVi) by ≥15%. We stated a directly proportional linear relationship between AHI value and LV volume: LVESVi p = 0.004, and LV end-diastolic volume index p = 0.006.

CONCLUSIONS

Pre-existing severe SDB can impair the LV volumetric response to CRT even in an optimally selected group with class I indications for resynchronization, which may have an impact on long-term prognosis.

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.

Update in approaches to pulmonary hypertension because of left heart disease

PURPOSE OF REVIEW

Left heart disease is the most common cause of pulmonary hypertension. This review summarizes the current care of patients with pulmonary hypertension caused by left heart disease (PH-LHD) and discusses recent and active clinical trials in this patient population.

RECENT FINDINGS

The primary focus of interventions aimed at treating PH-LHD address the treatment of left heart disease. Significant advancements in the treatment of heart failure with preserved ejection fraction (HFpEF), a frequent cause of PH-LHD, are supported in the current literature. Patients with residual pulmonary hypertension despite optimal treatment of left heart disease have poor outcomes. Yet, interventions targeting the pulmonary vasculature in PH-LHD patients have not demonstrated significant benefits in studies to date. Current work focuses on differentiating isolated postcapillary pulmonary hypertension (IpcPH) from combined precapillary and postcapillary pulmonary hypertension (CpcPH) in a clinically consistent manner. It is hopeful that thorough phenotyping of PH-LHD patients will translate into effective treatment strategies addressing pulmonary vascular disease.

SUMMARY

Referral to centers of excellence, considerations for enrollment in clinical trials, and evaluation for transplant is recommended for patients with residual pulmonary hypertension despite optimal treatment of left heart disease, particularly those with CpcPH.

Obstructive Sleep Apnea in Heart Failure: Current Knowledge and Future Directions

Obstructive sleep apnea (OSA) is highly prevalent among patients with asymptomatic left ventricular systolic and diastolic dysfunction and congestive heart failure, and if untreated may contribute to the clinical progression of heart failure (HF). Given the health and economic burden of HF, identifying potential modifiable risk factors such as OSA and whether appropriate treatment improves outcomes is of critical importance. Identifying the subgroups of patients with OSA and HF who would benefit most from OSA treatment is another important point. This focused review surveys current knowledge of OSA and HF in order to provide: (1) a better understanding of the pathophysiologic mechanisms that may increase morbidity among individuals with HF and comorbid OSA, (2) a summary of current observational data and small randomized trials, (3) an understanding of the limitations of current larger randomized controlled trials, and (4) future needs to more accurately determine the efficacy of OSA treatment among individuals with HF.

Abnormal Sleep-Related Breathing Related to Heart Failure

Sleep-disordered breathing (SDB) is highly prevalent in patients with heart failure (HF). Untreated obstructive sleep apnea (OSA) and central sleep apnea (CSA) in patients with HF are associated with worse outcomes. Detailed sleep history along with polysomnography (PSG) should be conducted if SDB is suspected in patients with HF. First line of treatment is the optimization of medical therapy for HF and if symptoms persist despite optimization of the treatment, positive airway pressure (PAP) therapy will be started to treat SDB. At present, there is limited evidence to prescribe any drugs for treating CSA in patients with HF. There is limited evidence for the efficacy of continuous positive airway pressure (CPAP) or adaptive servo-ventilation (ASV) in improving mortality in patients with heart failure with reduced ejection fraction (HFrEF). There is a need to perform well-designed studies to identify different phenotypes of CSA/OSA in patients with HF and to determine which phenotype responds to which therapy. Results of ongoing trials, ADVENT-HF, and LOFT-HF are eagerly awaited to shed more light on the management of CSA in patients with HF. Until then the management of SDB in patients with HF is limited due to the lack of evidence and guidance for treating SDB in patients with HF.

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.

Adaptive servo ventilation for sleep apnoea in heart failure: the FACE study 3-month data

Rationale

Adaptive servo ventilation (ASV) is contraindicated in patients with systolic heart failure (HF) who have a left ventricular ejection fraction (LVEF) below 45% and predominant central sleep apnoea (CSA). However, the effects of ASV in other HF subgroups have not been clearly defined.

Objective

The European, multicentre, prospective, observational cohort trial, FACE, evaluated the effects of ASV therapy on morbidity and mortality in patients with HF with sleep-disordered breathing (SDB); 3-month outcomes in patient subgroups defined using latent class analysis (LCA) are presented.

Methods

Consecutive patients with HF with predominant CSA (±obstructive sleep apnoea) indicated for ASV were included from 2009 to 2018; the non-ASV group included patients who refused/were noncompliant with ASV. The primary endpoint was time to composite first event (all-cause death, lifesaving cardiovascular intervention or unplanned hospitalisation for worsening of chronic HF).

Measurements and main results

Baseline assessments were performed in 503 patients, and 482 underwent 3-month follow-up. LCA identified six discrete patient clusters characterised by variations in LVEF, SDB type, age, comorbidities and ASV acceptance. The 3- month rate of primary outcome events was significantly higher in cluster 1 patients (predominantly men, low LVEF, severe HF, CSA; 13.9% vs 1.5%–5% in other clusters, p<0.01).

Conclusion

For the first time, our data identified homogeneous patient clusters representing clinically relevant subgroups relating to SDB management in patients with HF with different ASV usage, each with a different prognosis. This may improve patient phenotyping in clinical practice and allow individualisation of therapy.

Predictive value of sleep apnea screenings in cardiac surgery patients

INTRODUCTION

Obstructive sleep apnea (OSA) is a highly prevalent disorder associated with increased cardiovascular risks. We explored the predictive value of OSA screening instruments in cardiac disease patients awaiting cardiac surgery.

METHODS

In this prospective cohort, 107 participants awaiting cardiac surgery from Cleveland Clinic and Johns Hopkins underwent polysomnography after completing Epworth Sleepiness Scale (ESS), Sleep Apnea/Sleep Disorder Questionnaire (SA/SDQ), STOP, STOPBAG₂ and Berlin questionnaires. Score comparisons between groups based on apnea-hypopnea index (AHI) ≥15 were performed. Logistic regression with receiver operating characteristic (ROC) analysis was used to investigate optimal threshold.

RESULTS

Prevalence of OSA (AHI ≥5) was 71.9% (77/107) and 51 (47.7%) had moderate-to-severe disease (AHI ≥15). Participants were primarily male (57%) and Caucasian (76.6%). Mean age was 67.3 ± 13.3 years and BMI was 26.5 ± 6.6. Of the five screening tools, STOPBAG₂ with a cut-point of 0.381 provided 78% sensitivity and 38% specificity (AUC 0.66, 95%CI 0.55-0.77). SA/SDQ yielded a cut-point of 32 for all subjects (AUC: 0.62, 95%CI 0.51-0.73) with sensitivity and specificity of 60% and 62% respectively, while STOP score ≥2 provided sensitivity and specificity of 67% and 52% respectively (AUC: 0.61, 95%CI 0.51-0.72). Among STOP items, "observed apnea" had the strongest correlation with AHI ≥15 (OR 3.67, 95%CI 1.57-8.54, p = 0.003). The ESS and Berlin were not useful in identifying moderate-to-severe OSA.

CONCLUSION

Common screening tools had suboptimal performance in cardiac surgery patients. STOPBAG₂ was better at predicting the probability of moderate-to-severe OSA in patients undergoing cardiac surgery compared to ESS, SA/SDQ, STOP and Berlin questionnaires.

In patients with heart failure, enhanced ventilatory response to exercise is associated with severe obstructive sleep apnea

STUDY OBJECTIVES

Patients with chronic heart failure (CHF) while undergoing exercise test, frequently exhibit elevated ratio of minute ventilation over CO₂ output (VE/VCO₂ slope). One of the factors contributing to this elevated slope is increased chemosensitivity to CO₂, as this slope significantly correlates with the slope of the ventilatory response to CO₂ rebreathing at rest. A previous study in patients with CHF and central sleep apnea (CSA) has shown the highest VE/VCO2 slope during exercise was associated with the most severe CSA. In the current study, we tested the hypothesis that in patients with CHF and obstructive sleep apnea (OSA), the highest VE/VCO₂ slope is also associated with most severe OSA. If correct, it implies that in CHF, augmented instability in the negative feedback system controlling breathing predisposes to both OSA and CSA.

METHODS

This preliminary study involved 70 patients with stable CHF and spectrum of OSA severity who underwent full night polysomnography, echocardiography, and cardiopulmonary exercise testing. Peak oxygen consumption (VO₂ max) and VE/VCO₂ slope were calculated.

RESULTS

There were significant positive correlations between apnea hypopnea index (AHI) and VE/VCO₂ slope (r= 0.359; p=0.002). In the regression model, involving relevant variable, age, body mass index, gender, VE/VCO₂ slope, VO₂, and left ventricular ejection fraction, AHI retained significance with VE/VCO₂.

CONCLUSIONS

In patients with CHF, the VE/VCO₂ slope obtained during exercise correlates significantly to the severity of OSA suggesting that an elevated CO₂ response should increase suspicion for presence of severe OSA, a treatable disorder that is potentially associated with excess mortality.

CLINICAL TRIAL REGISTRATION: REGISTRY

ClinicalTrials.gov; Title: Comparison Between Exercise Training and CPAP Treatment for Patients With Heart Failure and Sleep Apnea; Identifier: NCT01538069; URL: https://clinicaltrials.gov/ct2/show/record/NCT01538069.

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.

All You Need Is Sleep: the Effects of Sleep Apnea and Treatment Benefits in the Heart Failure Patient

PURPOSE OF REVIEW

Recognition and treatment of sleep apnea is an important but easily overlooked aspect of care in the heart failure patient. This review summarizes the data behind the recommendations in current practice guidelines and highlights recent developments in treatment options.

RECENT FINDINGS

Neuromodulation using hypoglossal nerve stimulation has been increasingly used for treatment of OSA; however, it has not been studied in the heart failure population. Alternatively, phrenic nerve stimulation for treatment of CSA is effective for heart failure patients, and cardiac resynchronization therapy can be effective in improving CSA in pacing-induced cardiomyopathy. In patients suspected to have sleep apnea, polysomnography is recommended to better understand the prognosis and treatment options. Positive airway pressure is the standard treatment for sleep apnea; however, neurostimulation can be especially effective in those with predominantly central events. Understanding the pathophysiology of sleep apnea can guide further management decisions.

Obstructive sleep apnea and cardiovascular disease, a story of confounders!

Obstructive sleep apnea (OSA) syndrome is increasingly common among middle aged and older adults and is frequently linked to most cardiovascular diseases (CVD). Sleep-disordered breathing and CVD share a number of common risk factors and comorbid conditions including obesity, male gender, advancing age, metabolic syndrome, and hypertension. OSA appears to be associated with worsened CVD outcomes, sleep-related symptoms, quality of life, and risk of motor vehicle accidents. Demonstrating a cause-and-effect relationship between CVD and OSA has been challenging due to shared comorbidities. Strong evidence demonstrating clinically significant benefit for OSA treatments on OSA-related CVD outcomes are limited. In this review, we evaluate potential pathophysiologic mechanisms that link OSA to CVD and focus on specific treatments for OSA, including positive airway pressure (PAP), dental devices, and surgeries with regard to OSA-related CVD outcomes.