Obstructive Sleep Apnea and Structural/Functional Properties of the Thoracic Ascending Aorta: The Multi-Ethnic Study of Atherosclerosis (MESA)

Efficacy analysis of non-invasive positive pressure ventilation in elderly patients with heart failure complicated with obstructive sleep apnea syndrome

BACKGROUND

It is recommended to use non-invasive positive pressure ventilation in elderly patients with heart failure combined with obstructive sleep apnea syndrome (OSAS).

OBJECTIVE

To study the therapeutic effect of non-invasive positive pressure ventilation on elderly patients with heart failure complicated with OSAS.

METHODS

Using the random number table method, 119 elderly patients with heart failure complicated with OSAS who were admitted to our hospital from April 2020 to April 2021 were divided into the observation (60 cases) and control (59 cases) groups. On the basis of conventional drug treatment, patients in the observation group were treated with non-invasive positive pressure ventilation, and patients in the control group were treated with low-flow oxygen inhalation. The sleep quality, hemoglobin, red blood cells, erythropoietin, pro-brain natriureticpeptide (pro-BNP) levels and blood pressure were compared.

RESULTS

After treatment, levels of hemoglobin, erythrocytes, erythropoietin, pro-BNP, blood pressure and sleep apnea-hypopnea index in the observation group were lower before treatment and in the control group in the same period. The oxygen saturation was higher before treatment and the control group in the same period (P< 0.05). The overall satisfaction with sleep quality in the observation group was higher (P< 0.05).

CONCLUSION

Non-invasive positive pressure ventilation can improve blood oxygen saturation and sleep quality in elderly patients with heart failure complicated with OSAS, and reduce pro-BNP level.

Arterial Stiffness Associated with Sympathetic Hyperactivity in Obese Individuals with Moderate to Severe Obstructive Sleep Apnea

INTRODUCTION

Obstructive Sleep Apnea (OSA) is a chronic disorder associated with several risk factors, and increased Body Mass Index (BMI) and waist circumference are correlated with it is severity.

AIM

To evaluate vascular function, central hemodynamics, and autonomic modulation in obese individuals with moderate and severe OSA.

METHODS

Individuals of both sexes, aged 40-70 years and BMI ≥ 30 and < 40 kg/m², were submitted to assessment of heart rate variability, endothelial function by flow-mediated dilatation, central parameters by oscillometry and carotid ultrasound. The sleep study was performed through a portable home sleep test device (WatchPAT).

RESULTS

Patients (n = 76) were divided according to Apnea-Hypopnea Index (AHI): absent-mild group (AHI < 15 events/h, n = 30) and Moderate-Severe (MS) group (AHI ≥ 15 events/h, n = 46). The Low/High Frequency (LF/HF) ratio (0.81  ±  0.48 vs 1.39  ±  1.08 ms², p = 0.035), Pulse Wave Velocity (PWV; 6.9  ±  0.7 vs 7.7  ±  1.6m/s, p = 0.004), vascular age (48  ±  6 vs 53  ±  9 years, p = 0.05) and mean intima-media thickness (0.59  ±  0.08 vs 0.66  ±  0.13 mm, p = 0.011) were significantly higher in the MS group. AHI was significantly correlated with PWV (r = 0.26, p = 0.024) and LF/HF ratio (r = 0.40, p < 0.001). Only in the MS group, PWV was significantly correlated with SD2/SD1 ratio (r = 0.611, p ≤ 0.001), and flow-mediated dilation with central systolic blood pressure (r = 0.364, p = 0.018), even after adjustment for age and sex.

CONCLUSION

In this sample of obese individuals, moderate to severe OSA was associated with sympathetic hyperactivity and evidence of accelerated vascular aging with arterial stiffness and subclinical atherosclerosis.

Impact of obstructive sleep apnea on aortic disease occurrence: a meta-analysis

Objective

Aortic diseases, mainly including aortic dilatation, aortic aneurysm (AA) and aortic dissection (AD), have high morbidity and mortality. Many studies have suggested that obstructive sleep apnea (OSA) acts as a candidate risk factor for aortic diseases. Thus, we performed a meta-analysis to explore comprehensively the effect of OSA on the risk of aortic disease occurrence.

Methods

We searched PubMed, Embase and Cochrane Library databases from inception to February 2022 to identify studies investigating the association between OSA and aortic diameter dilatation, the prevalence of OSA in individuals with or without AA/AD and the incidence of AA/AD in individuals with or without OSA. The Newcastle-Ottawa Scale (NOS) and the Agency for Healthcare Research and Quality (AHRQ) were respectively used to evaluate the quality of the included cohort and cross-sectional studies. A random or fixed effect model was used to generate pooled effects according to interstudy heterogeneity. Sensitivity analyses were performed to test the robustness of the results.

Results

We identified 10 observational publications with 214,127 participants in this meta-analysis. OSA was significantly associated with increased aortic diameter (WMD = 1.46, 95% CI, 1.10–1.83, p < 0.001). OSA prevalence was higher in patients with AA/AD compared to their counterparts without AA/AD (OR = 1.90, 95% CI, 1.30–2.76, p = 0.001). No significant difference in the incidence of AA/AD was observed in individuals with or without OSA (RR = 0.85, 95% CI, 0.62–1.16, p = 0.307). Sensitivity analyses did not modify these results.

Conclusions

This meta-analysis suggests that OSA is associated with aortic diameter dilatation but does not affect AA/AD occurrence.

Sleep Apnea Syndrome and Large Artery Subclinical Damage: Targeting Thoracic Aortic Dilatation

AIM

Whether obstructive sleep apnea (OSA) actually represents an independent risk factor for aortic dilation in the general population is unclear. We investigated this issue through a review and a meta-analysis of cardiac imaging studies that provided data on this vascular phenotype measured at the root or ascending tract level.

DESIGN

A computerized search was performed using Pub-Med, OVID, EMBASE, and Cochrane library databases from inception up to 30 November 2021. Studies were identified by using the following search terms: "aortic root," "ascending aorta," "vascular damage," "echocardiography," "computed tomography," "magnetic resonance imaging," "obstructive sleep apnea," "sleep disordered breathing."

RESULTS

Eleven studies including a total of 1,860 patients with OSA (without aortic aneurysms and connective tissue diseases) and 233 non-OSA controls were considered. Aortic diameter was significantly higher in patients with OSA than in non-OSA controls (standard means difference [SMD] = 0.73 ± 0.08, confidence interval [CI]: 0.57-0.88, P < 0.0001). This was also the case for patients with severe OSA as compared with their counterparts with mild OSA (SMD = 0.42 ± 0.07, CI: 0.28-0.56, P < 0.0001).

CONCLUSIONS

Our findings suggest an association between OSA and aortic enlargement and particularly in the severe OSA setting. However, this conclusion must be taken with caution in relation to 2 types of factors: (i) the paucity of available data, and (ii) the limits deriving from the methodological differences of the various studies. Larger prospective and carefully designed studies are needed to shed light on this relevant public health topic.

Cardiovascular remodeling in obstructive sleep apnea: focus on arterial stiffness, left ventricular geometry and atrial fibrillation

INTRODUCTION

Obstructive sleep apnea (OSA) is a common sleep-related breathing disorder that is associated with increased risk of cardiovascular disease. The main interest of this clinical review is to discuss the cardiovascular consequences of OSA with a special focus on left ventricular (LV) function and structure, arterial stiffness and atrial fibrillation.

AREA COVERED

We present an overview of the definition, prevalence, and risk factors of OSA and outline the association between OSA and cardiovascular complications. We then briefly discuss echocardiographic assessment in OSA with focus on the left atrium and LV. Finally, we highlight the importance of adherence to continuous positive airway pressure (CPAP) therapy with regard to reducing the risk of cardiovascular disease.

EXPERT COMMENTARY

Although OSA has a strong association with cardiovascular complications, it is often underdiagnosed and undertreated. Patients with resistant hypertension and atrial fibrillation with poor therapeutic success after cardioversion or catheter ablation should be more often screened for OSA. Patients with nocturnal adverse cardiovascular events (stroke, arrhythmias, angina, coronary events) should be closely assessed with regard to OSA, and if confirmed, timely treated by lifestyle modification, CPAP, and aggressive antihypertensive treatment. Adherence to CPAP in OSA patients is essential in terms of reducing the risk of cardiovascular events.

Obstructive sleep apnea in patients with acute aortic dissection

Background

Obstructive sleep apnea (OSA) imposes an afterload burden on the left ventricle and increases the pressure gradient across the aortic wall. Thus, OSA may increase the risk for aortic dissection (AD).

Methods

This study enrolled 40 subjects with acute AD from four institutions; 37 completed the modified Berlin Questionnaire and 31 underwent attended overnight polysomnography. Aortic diameter was measured on a computed tomography scan at seven locations from the sinotubular junction to the diaphragm.

Results

Twenty‐seven subjects had type A dissection; 13 had type B. In those who had polysomnography apnea–hypopnea index (AHI) ranged from 0.7 to 89. Prevalence of OSA (AHI ≥ 5) was 61%. Nocturnal presentation (10 p.m.–7 a.m.) did not differ by presence/absence of OSA. The modified Berlin Questionnaire was not predictive of the presence of OSA. Among type A subjects with polysomnography (n = 23), aortic diameters at all locations were greater in the OSA group though differences were not statistically significant. Summating aortic diameters at the seven locations also yielded a numerically larger mean value in the OSA group versus the non‐OSA group.

Conclusions

In this sample of patients with acute dissection, OSA was prevalent but was not associated with a nocturnal presentation. The presence of underlying OSA may be associated with larger aortic diameters at the time of dissection compared to patients without OSA. Though differences did not meet statistical significance the current series is limited by small numbers.

Characteristics of hypertension and arterial stiffness in obstructive sleep apnea: A Scandinavian experience from a prospective study of 6408 normotensive and hypertensive patients

The impact of obstructive sleep apnea (OSA) on arterial stiffness is less studied. We aimed to investigate the prevalence and covariates of increased pulse pressure (PP), a surrogate marker of arterial stiffness, in the entire study population as well as in separate analyses in normotensive and hypertensive patients. Further, we also explored the impact of smoking on brachial BP in hypertensive patients. Between 2012 and 2019, a total of 6408 participants with suspected OSA underwent a standard out-of-center respiratory polygraphy. OSA was defined by an apnea-hypopnea index (AHI) ≥15/h regardless of symptoms. PP ≥60 mmHg was used as a surrogate marker of increased arterial stiffness. Mean age was 49.3±13.7 years, 69.4% were male, and 34.5% had OSA. The prevalence of hypertension was 70.8% in OSA and 46.7% in No-OSA (AHI < 15/h) controls (P < .0001). Hypertension was controlled (clinic BP < 140/90 mmHg) in 45.5% and uncontrolled in 54.5% (P < .001). Mean PP was 50±12 mmHg in smokers and 52±12 mmHg in non-smokers (P = .001). Increased PP was found in 24.2% of the entire study population and was higher in patients with OSA compared to No-OSA group (27.5% vs 22.4%, P < .0001). In an unadjusted logistic regression model, OSA was associated with a 1.3-fold higher risk of having increased PP (95% CI 1.16-1.48, P < .001). In a multivariable-adjusted model, higher age, male sex, and history of hypertension, but not OSA (OR 0.89; 95% CI 0.77-1.02, P = .104) were associated with increased PP. In this large study of nearly 6500 participants who were referred with suspected OSA, one-third were diagnosed with OSA and a quarter had increased arterial stiffness by elevated brachial PP. Hypertension but not OSA per se was associated with increased arterial stiffness. Hypertension was highly prevalent and poorly controlled.

Intermittent hypoxia-related alterations in vascular structure and function: a systematic review and meta-analysis of rodent data

Obstructive Sleep Apnea and the related intermittent hypoxia (IH) are widely recognised as risk factors for incident cardiovascular diseases. Numerous studies support the deleterious vascular impact of IH in rodents but an overall interpretation is challenging owing to heterogeneity in rodent species investigated and the severity and duration of IH exposure.To clarify this major issue, we conducted a systematic review and meta-analysis to quantify the impact of IH on systemic artery structure and function depending on the different IH exposure designs.We searched PubMed, Embase and Web of Sciences and included 125 articles in a meta-analysis, among them 112 using wild-type rodents and 13 using Apolipoprotein E knock-out mice. We used the standardised mean difference (SMD) to compare results between studies.IH significantly increased mean arterial pressure (+13.90 mmHg (95% CI [11.88; 15.92]), systolic and diastolic blood pressure. Meta-regressions showed that mean arterial pressure change was associated with strain and year of publication. IH altered vasodilation in males but not in females, and increased endothelin-1-induced, but not phenylephrine-induced, vasoconstriction. Intima-media thickness significantly increased upon IH exposure (SMD 1.10 [0.58; 1.62], absolute values: +5.23 (2.81-7.84)). This increase was observed in mice but not in rats, and was negatively associated with age. Finally IH increased atherosclerotic plaque size in ApoE-/- mice (SMD 1.08 [0.80; 1.37]).To conclude, our meta-analysis established that IH, independently of other confounders, has a strong effect on vascular structure and physiology. Our findings support the interest of identifying and treating sleep apnea in routine cardiology practice.

Cardiac imageology changes in patients with mild obstructive sleep apnea without cardiovascular disease

PURPOSE

This study aims to assess changes in cardiac imageology of patients with mild obstructive sleep apnea (OSA) without cardiovascular disease.

METHODS

All enrolled participants underwent polysomnography (PSG). Some participants underwent transthoracic echocardiography, speckle tracking echocardiography, and cardiac-enhanced magnetic resonance imaging (MRI) if they were willing. They were divided into three groups according to PSG results: non-OSA, mild OSA, and moderate-to-severe OSA. Imageology parameters were compared, and the relationship between OSA severity and imageology indices was analyzed by correlation analysis and multiple linear regression.

RESULTS

Of the 352 enrolled participants, 274 participants with OSA had an apnea-hypopnea index (AHI) of ≥ 5 (86 mild OSA and 188 moderate-to-severe OSA cases), and 78 participants with non-OSA had an AHI of < 5. Transthoracic echocardiography showed that E/A and E'/A' values were lower in the mild OSA group than in the non-OSA group (1.12 ± 0.37 vs 1.27 ± 0.45 and 0.83 ± 0.33 vs 0.99 ± 0.42, respectively, p < 0.05). The aorta and ascending aorta widths were smaller in the mild OSA group than in the moderate-and-severe OSA groups (27.36 ± 2.87 mm vs 28.87 ± 2.95 mm and 30.27 ± 3.79 mm vs 31.63 ± 3.74 mm, respectively, p < 0.05). A regression analysis showed that cardiac function changes in patients with OSA may be related to age, obesity, and OSA severity.

CONCLUSION

Patients with mild OSA without cardiovascular disease displayed changes in cardiac structure and function on transthoracic echocardiography.

Targeting subclinical organ damage in obstructive sleep apnea: a narrative review

Subclinical abnormalities in cardiac and vascular structure reflect the adverse effects triggered by a variety of risk factors on the cardiovascular (CV) system thereby representing an intermediate step in the cardiovascular continuum; such alterations are recognized as reliable markers of increased cardiovascular risk in different clinical settings including obstructive sleep apnea (OSA). The mechanisms underlying subclinical organ damage (OD) in the OSA setting are multifactorial. Hypoxemia and hypercapnia, induced by repeated collapses of upper airways, have been suggested to trigger a cascade of events such as activation of the sympathetic tone, renin-angiotensin-aldosterone system leading to endothelial dysfunction, vasoconstriction, myocardial and vascular remodeling, and hypertension. Furthermore, coexisting non-haemodynamic alterations such as increased oxidative stress, release of inflammatory substances, enhanced lipolysis and insulin resistance have been reported to play a role in the pathogenesis of both cardiac and extra-cardiac OD. In this article we reviewed available evidence on the association between OSA and subclinical cardiac (i.e., left and right ventricular hypertrophy, left atrial dilatation) and extra-cardiac organ damage (i.e., carotid atherosclerosis, arterial stiffness, microvascular retinal changes, and microalbuminuria). This association is apparently stronger for cardiac and carotid subclinical damage than for other markers (i.e., arterial stiffness and retinal changes) and mostly evident in the setting of severe OSA.