Coexistence of visceral fat accumulation and sleep-disordered breathing correlates with coronary artery disease

Aim: Visceral adiposity is linked with sleep-disordered breathing (SDB) (called Syndrome Z), and both correlate with coronary artery disease (CAD). The aim of the present study was to determine the significance of excess visceral fat, SDB and circulating levels of biomarkers in CAD in Japanese men.Methods: SDB, visceral fat area (VFA), and circulating levels of biomarkers were assessed in 60 Japanese male patients who underwent coronary angiography and overnight cardiorespiratory monitoring.Results: Age-adjusted logistic analysis showed a significant relationship between CAD and diabetes, hypertension, dyslipidemia, SDB (AHI ≥5 events/hour), visceral fat accumulation (VFA ≥100 cm(2)), the combination of visceral fat accumulation and hypertension or dyslipidemia, as well as the combination of visceral fat accumulation and SDB. Patients with VFA ≥100 cm(2) and SDB had significantly lower serum adiponectin levels and higher serum soluble CD40 ligand levels than those with VFA<100 cm(2) and SDB. The prevalence of CAD was significantly higher in patients with VFA ≥100 cm(2) and SDB than in patients with VFA <100 cm(2) and AHI <5 events/hour, patients with VFA<100 cm(2) and AHI ≥5 events/hour or patients with VFA ≥100 cm(2) and AHI <5 events/hour (93% versus 14%, p <0.001, 53%, p <0.01 or 63%, p <0.01, respectively).Conclusions: The present study indicates that patients with both visceral fat accumulation and SDB develop CAD in association with hypoadiponectinemia and inflammatory activity.     

Washout Rate of Cardiac Iodine-123 Metaiodobenzylguanidine is High in Chronic Heart Failure Patients With Central Sleep Apnea

BackgroundThe association between sleep-disordered breathing (SDB) assessed by polysomnography and cardiac sympathetic nerve activity (SNA) assessed by cardiac iodine-123 metaiodobenzylguanidine (123I-MIBG) imaging has not been investigated in patients with chronic heart failure (CHF).Methods and ResultsWe performed cardiac 123I-MIBG scintigraphy and overnight polysomnography in 59 patients with stable CHF. The patients were classified into the 3 groups: 19 with no or mild SDB (NM-SDB, apnea-hypopnea index <15); 21 with central sleep apnea (CSA), and 19 with obstructive sleep apnea (OSA). The cardiac washout rate (WR) of 123I-MIBG was obtained from initial and delayed planar 123I-MIBG images. The WR was higher in patients with CSA (54.2 ± 11.6%) than in those with OSA (37.9 ± 8.6%, P < .05) or NM-SDB (40.8 ± 8.8%, P < .05). The WR correlated positively with central apnea index (ρ = 0.40, P = .002). A stepwise multiple regression analysis selected CSA and plasma brain natriuretic peptide levels as independent variables associated with the WR.ConclusionsThe WR was higher in CHF patients with CSA than in those with OSA or NM-SDB, and CSA was independently associated with the WR, suggesting a link of CSA to increased cardiac SNA in CHF.     

Prevalence and clinical characteristics of sleep apnea in Chinese patients with heart failure

One hundred twenty-six eligible consecutive Chinese heart failure (HF) patients classified by New York Heart Association (NYHA) Classes II-IV underwent historic data collection and a sleep study. Seventy-one percent of HF patients were diagnosed with sleep apnea (SA), of which 65% were central sleep apnea (CSA) and 35% were obstructive sleep apnea (OSA). Higher body mass index (BMI), metabolic syndrome, habitual snoring, and nocturia were independent risk factors for OSA; NYHA classes III and IV were independent risk factors for CSA in the HF patients. There was a high prevalence of SA in Chinese patients with HF. HF patients with obesity, metabolic syndrome, snoring, nocturia and NYHA classes III and IV were more susceptible to OSA and CSA.     

Impact of sleep-disordered breathing, visceral fat accumulation and adiponectin levels in patients with night-time onset of acute coronary syndrome

Acute coronary syndrome (ACS) during sleep occurs at a relatively low frequency and the pathogenic background remains uncertain. The aim of the present study was to determine the significance of sleep-disordered breathing (SDB) and excess visceral fat with nocturnal dysregulation of adipocytokines in night-time onset of ACS. SDB, visceral fat area (VFA), and changes in circulating adipocytokine levels were assessed in 109 consecutive patients with ACS. SDB and VFA were assessed by cardiorespiratory monitoring and computed tomographic scan, respectively. Visceral fat accumulation was more common in patients with (12 to 7 a.m.) than without (7 to 12 a.m.) night-time onset of ACS (p <0.05). In patients with night-time onset of ACS, those with excess visceral fat were significantly more likely to have SDB and nocturnal dysregulation of adiponectin than those without such accumulation (p <0.05), but there was no difference between those with and without excess visceral fat (VFA cutoff 100 cm(2)) in patients with non-night-time onset of ACS. In conclusion, night-time onset of ACS is associated with excess visceral fat and SDB (referred as to "syndrome Z"). SDB and excess visceral fat are treatable risk factors. Decrease of excess visceral fat and treatment of SDB could be beneficial in in preventing nocturnal cardiac events.     

Metabolic syndrome correlates intracoronary stenosis detected by multislice computed tomography in male subjects with sleep-disordered breathing

Background

Sleep-disordered breathing (SDB), especially obstructive sleep apnea (OSA), has frequent complications include hypertension, dyslipidemia and insulin resistance based on abdominal obesity or excess visceral fat (called Syndrome Z). OSA is a potential risk factor for cardiovascular diseases. The clinical characteristics of Japanese OSA subjects with OSA remain unclear. The present study investigated prevalence and predictive factors of intracoronary stenosis detected by multislice computed tomography (MSCT) in Japanese male subjects with SDB/OSA.

Findings

The study (O-VFStudy) subjects were 39 Japanese men with SDB/OSA who underwent all-night cardiorespiratory monitoring with fully attended polysomnography, and moreover both fat computed tomography (CT) scan and 64-row MSCT coronary angiography. The prevalence of coronary stenosis in this selected population with SDB/OSA was 15%. Logistic regression analysis showed a significant relationship between age-adjusted CAD and metabolic syndrome (p < 0.05), but not serum adiponectin levels and nocturnal fall in adiponectin. Subjects with the metabolic syndrome had significantly higher prevalence of CAD (31.3 versus 4.3%, p = 0.033), and lower levels of serum adiponectin (4.5 ± 0.6 versus 6.4 ± 0.6 μg/mL, p = 0.014), compared with groups without the metabolic syndrome.

Conclusions

The present study describes that the prevalence of greater than 50% intracoronary stenotic lesions detected by MSCT was 15% and the metabolic syndrome was correlated with intracoronary stenosis detected by MSCT in Japanese SDB/OSA subjects.

Trial Registration

UMIN 000002997 https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr.cgi?function=brows&action=brows&type=summary&recptno=R000003633&language=E.     

Central sleep apnea is a predictor of cardiac readmission in hospitalized patients with systolic heart failure

BackgroundHospitalized heart failure patients have a high readmission rate. We sought to determine the independent risk due to central sleep apnea (CSA) of readmission in patients with systolic heart failure (SHF).Methods and ResultsThis was a prospective observational cohort study of hospitalized patients with SHF. Patients underwent sleep studies during their hospitalization and were followed for 6 months to determine their rate of cardiac readmissions; 784 consecutive patients were included; 165 patients had CSA and 139 had no sleep-disordered breathing (SDB); the remainder had obstructive sleep apnea (OSA). The rate ratio for 6 months' cardiac readmissions was 1.53 (95% confidence interval 1.1–2.2; P = .03) in CSA patients compared with no SDB. This rate ratio was adjusted for systolic function, type of cardiomyopathy, age, weight, sex, diabetes, coronary disease, length of stay, admission sodium, creatinine, hemoglobin, blood pressure, and discharge medications. Severe OSA was also an independent predictor of readmissions with an adjusted rate ratio of 1.49 (P = .04).ConclusionIn this first evaluation of the impact of SDB on cardiac readmissions in heart failure, CSA was an independent risk factor for 6 months' cardiac readmissions. The effect size of CSA exceeded that of all known predictors of heart failure readmissions.     

Characteristics of sleep-disordered breathing in Japanese patients with acromegaly

Sleep-disordered breathing (SDB), especially sleep apnea-hypopnea syndrome (SAS), is often observed in patients with active acromegaly. This complication is a risk factor for cardiovascular disease and associated with increased morbidity and mortality in acromegaly. However there is little information on SDB in Japanese patients with acromegaly. We investigated the prevalence of SDB and association between the severity of SDB and various features and biomarkers in Japanese patients with acromegaly. Twenty-four Japanese patients with active acromegaly underwent overnight cardiorespiratory monitoring, hormonal assays and cephalometric measurements on X-ray. A high prevalence of SDB was detected in acromegaly (87.5%). Log apnea-hypopnea index (AHI) correlated positively with soft palate length / body height (X-ray) (r=0.44, p=0.043), but not with log growth hormone levels and insulin-like growth factor type-1 standard deviation scores, size of pituitary adenoma, disease duration, body mass index, waist circumference, estimated visceral fat area, heel pad thickness / height, tongue thickness/ height, or oropharyngeal dimension/ height. In conclusion, our study demonstrated a high prevalence of SDB in Japanese patients with acromegaly, and its severity correlated with soft palate length. Based on the high incidence of SDB identified in the present study, we recommend that all patients with acromegaly are routinely screened for SDB for early diagnosis and treatment.     

A high prevalence of sleep disordered breathing in men with mild symptomatic chronic heart failure due to left ventricular systolic dysfunction

BACKGROUND: Sleep disordered breathing (SDB) is common in severe chronic heart failure (CHF) and is associated with increased morbidity and mortality. The prevalence of SDB in mild symptomatic CHF is unknown. AIM: The aim of this study was to determine the prevalence and characteristics of SDB in male patients with NYHA class II symptoms of CHF. METHODS AND RESULTS: 55 male patients with mild symptomatic CHF underwent assessment of quality of life, echocardiography, cardiopulmonary exercise, chemoreflex testing and polysomnography. 53% of the patients had SDB. 38% had central sleep apnoea (CSA) and 15% had obstructive sleep apnoea. SDB patients had steeper VE/VCO(2) slope [median (inter-quartile range) 31.1 (28-37) vs. 28.1 (27-30) respectively; p=0.04], enhanced chemoreflexes to carbon dioxide during wakefulness [mean+/-sd: 2.4+/-1.6 vs. 1.5+/-0.7 %VE Max/mmHg CO(2) respectively; p=0.03], and significantly higher levels of brain natriuretic peptide and endothelin-1 compared to patients without SDB. No differences in left ventricular ejection fraction, percent predicted peak oxygen uptake, or symptoms of SDB were observed. CONCLUSIONS: A high prevalence of SDB was found in men with mild symptomatic CHF. Patients with SDB could not be differentiated by symptoms or by routine cardiac assessment making clinical diagnosis of SDB in CHF difficult.     

Detektion und Therapie respiratorischer Störungen durch implantierbare (kardiale) Devices

Sleep-disordered breathing (SDB) represents a common comorbidity in cardiac patients. The prevalence of obstructive sleep apnea (OSA) and central sleep apnea (CSA) is very high, particularly in patients with heart rhythm disorders and heart failure (HF). Patients with pacemakers (PM) and implantable defibrillators (ICD) including cardiac resynchronization therapy (CRT) show SDB prevalences up to 75%. However, some modern PM, ICD and CRT devices allow the detection of SDB via transthoracic impedance analysis with high sensitivity compared to polysomnographic (PSG) controls. Thus, this method could be of relevance in screening and monitoring SDB in patients with implantable cardiac devices. Preliminary studies demonstrated the possibility to treat OSA in selected patients by stimulation of the cranial nerves, especially the hypoglossal nerve. However, this requires extensive diagnostics and advanced surgical approaches including many medical disciplines and is not part of this review article. However, unilateral and transvenous stimulation of the phrenic nerve to treat central sleep apnea and Cheyne-Stokes respiration in HF patients in particular can be performed by cardiologists. This article summarizes preliminary data on the results of this promising therapy.     

Sleep-disordered breathing in patients with symptomatic heart failure: a contemporary study of prevalence in and characteristics of 700 patients

AIM: Evaluation of the prevalence and nature of sleep-disordered breathing (SDB) in patients with symptomatic chronic heart failure (CHF) receiving therapy according to current guidelines. METHODS AND RESULTS: We prospectively screened 700 patients with CHF (NYHA class> or =II, LV-EF< or =40%) for SDB using cardiorespiratory polygraphy (Embletta). Furthermore, echocardiography, cardiopulmonary exercise and 6-min walk testing were performed. Medication included ACE-inhibitors and/or AT1-receptor blockers in at least 94%, diuretics in 87%, beta-blockers in 85%, digitalis in 61% and spironolactone in 62% of patients. SDB was present in 76% of patients (40% central (CSA), 36% obstructive sleep apnoea (OSA)). CSA patients were more symptomatic (NYHA class 2.9+/-0.5 vs. no SDB 2.57+/-0.5 or OSA 2.57+/-0.5; p<0.05) and had a lower LV-EF (27.4+/-6.6% vs. 29.3+/-2.6%, p<0.05) than OSA patients. Oxygen uptake (VO(2)) was lowest in CSA patients: predicted peak VO(2) 57+/-16% vs. 64+/-18% in OSA and 63+/-17% in no SDB, p<0.05. 6-min walking distances were 331+/-111 m in CSA, 373+/-108 m in OSA and 377+/-118 m in no SDB (p<0.05). CONCLUSIONS: This study confirms the high prevalence of SDB, particularly CSA in CHF patients. CSA seems to be a marker of heart failure severity.     

Sleep‐disordered breathing in heart failure patients with different etiologies

BackgroundThe prevalence of sleep‐disordered breathing (SDB) is closely related to the severity of heart failure (HF), and the severity of HF is different in patients with HF of different etiologies. Hypothesis: This study aimed to explore the prevalence of SDB in patients with HFof different etiologies.MethodsHospitalized HF patients were consecutively enrolled. All patients underwent portable overnight cardiorespiratory polygraphy. Patients were divided into five groups according to the etiology of HF: ischemic, hypertensive, myocardial, valvular, and arrhythmic. The prevalence of SDB and clinical data was compared among the five groups.ResultsIn total, 248 patients were enrolled in this study. The prevalence of SDB in HF was 70.6%, with the prevalence of obstructive sleep apnea (OSA) at 47.6% and central sleep apnea (CSA) at 23.0%. Patients were divided into five groups: ischemic, hypertensive, myocardial, valvular, and arrhythmic. The prevalence of SDB among the five groups was 75.3%, 81.4%, 77.8%, 51.9%, and 58.5% (p = .014), respectively. The prevalence of OSA among the five groups was 42.7%, 72.1%, 36.1%, 37.0%, and 49.1% (p = .009), whereas the CSA was 32.6%, 9.3%, 41.7%, 14.8%, and 9.4% (p < .001), respectively.ConclusionsSDB is common in HF patients. The prevalence and types of SDB varied in HF with different etiologies, which may be related to the different severities of HF. SDB was highly prevalent in patients with ischemic, hypertensive, and myocardial HF. Hypertensive HF patients were mainly complicated with OSA, while myocardial HF patients were mainly complicated with CSA. Both conditions were highly prevalent in ischemic HF patients. The prevalence of SDB was relatively low in valvular and arrhythmic HF patients, and OSA was the main type.     

Schlafbezogene Atmungsst?rungen und kardiale Resynchronisationstherapie

Patients with progressive heart failure often suffer from sleep-disordered breathing (SDB). Upon receiving cardiac resynchronization therapy (CRT), there is an improvement of cardiac function and central sleep apnea syndrome (CSA) with Cheyne-Stokes respiration; however, effects of CRT on obstructive sleep apnea syndrome seemed to be without clinical relevance. Likewise, additional atrial overdrive pacing did not improve CRT effects relevantly in CSA patients. During CRT, there is an improvement in sleep parameters, sleep quality by reduction of depressive syndromes, and in long-term survival. Therefore, all patients with chronic heart failure and indication for CRT should be monitored regarding SDB before and after CRT device implantation.     

Evaluation and Treatment of Central Sleep Apnea in Patients with Heart Failure

Sleep-disordered breathing (SDB) is a common comorbidity in patients with heart failure (HF). Prevalence of the most common subtypes of SDB, central sleep apnea (CSA) and obstructive sleep apnea (OSA), is increasing, which is concerning due to the association of SDB with increased mortality in patients with HF. Despite an increasing burden of CSA in HF, it is difficult to detect using current diagnostic tools and the treatment modalities are limited by variable efficacy and patient adherence. Though positive airway pressure therapies remain the cornerstone of OSA treatment, the management of CSA in the setting of HF continues to evolve. The association of the presence of CSA with worse prognosis in HF patients warrants the need for routine screening for signs and symptoms of CSA in this population. In this review, we examine the connection between CSA and HF, and highlight advancements in timely diagnostics, treatment modalities, and strategies to promote facilitation of compliance in this high-risk cohort.     

Sleep-disordered breathing and epicardial adipose tissue in patients with heart failure

Background and aims

Sleep-disordered breathing (SDB) is common in patients with heart failure (HF), contributes to the progression of cardiac disease, and is associated with adverse prognosis. Previous evidence indicates that epicardial adipose tissue (EAT) is independently associated with sleep apnea in obese individuals. We explored the relationship between SDB and EAT in HF patients.

Incidence of sleep-disordered breathing in patients with hypertrophic cardiomyopathy

The authors investigated the prevalence of sleep-disordered breathing (SDB) together with its clinical correlations in patients with hypertrophic cardiomyopathy (HCM). A total of 113 consecutive patients including 63 patients with HCM (40 men; mean age, 59.5±13.0 years; New York Heart Association class, 2.0±0.9) underwent cardiorespiratory polygraphy in addition to their clinical work-up including echocardiography. Patients with an apnea-hypopnea-index (AHI) ≥5/h were considered to have SDB. If thoracic and abdominal inspiration efforts were documented, SDB was considered to be obstructive sleep apnea (OSA), otherwise SDB was considered to be central sleep apnea (CSA). The age- and sex-matched control group of 50 patients had exclusion of coronary artery disease by angiography, and normal left ventricular (ejection fraction ≥55%) and valvular function. SDB was diagnosed in 52 patients (82.5% vs 72% in the control group; P =not significant) with a mean AHI of 23.0±17.8/h. Severity of SDB was higher in patients with HCM than in the control group (AHI 12.2±7.6/h; P =.003). OSA was documented in 39 patients (AHI 21.2±16.5/h) and CSA in 13 (AHI 28.4±20.9/h). The severity of SDB correlated with New York Heart Association functional class (η=0.9, η(2) =0.811) and with left ventricular end-diastolic (r=0.6, P <.01) and left atrial (r=0.4, P <.01) diameter. No correlations were found between SDB and other clinical or echocardiographic parameters. SDB is common in patients with hypertrophic cardiomyopathy, with a predominance of OSA and correlations with markers of left ventricular function.     

A systematic review of central sleep apnea in adult patients with chronic kidney disease

Background

Obstructive sleep apnea has been widely studied in patients with chronic renal insufficiency; however only a limited number of studies have reviewed the association between central sleep apnea (CSA) and chronic kidney disease (CKD). The objectives of this systematic review were to assess the prevalence of CSA in and its association with CKD in adult patients and to determine if inclusion of the central hypopnea index affected the reported rates for the prevalence of CSA in CKD.

Methods

Medline, Web of Science, Google Scholar, Scopus, and Cochrane Library were searched through October 2015 without any language limitations.

Results

Of 188 articles searched, 8 articles met our study inclusion criteria. Of a cumulative total of 313 patients with CKD undergoing sleep study, a total of 30 patients were diagnosed with central sleep apnea. Three studies had patients with coexistent congestive heart failure, six studies included some patients on dialysis and at least 3 studies included central hypopneas while calculating central sleep apnea index.

Conclusion

The aggregate point prevalence of CSA in CKD is 9.6 %, although the estimated range is highly variable between 0 and 75 %. Limited evidence suggested that even after adjustment for cardiovascular comorbidities, CKD is independently associated with CSA. It is unknown if patients on dialysis are at increased risk compared to patients without end-stage renal disease. Standardization of polysomnographic criteria used to define CSA and sleep disordered breathing (SDB) as well as inclusion of central hypopneas in the overall CSA index will limit the heterogeneity and allow better estimation of the prevalence of CSA in patients with CKD.

     

Treatment of central sleep apnea in patients with heart failure: Now and future

Heart failure (HF) is known to be associated with sleep-disordered breathing (SDB). In addition to disturbing patients’ sleep, SDB is also associated with a deterioration in the cardiac function and an increased mortality and morbidity. Central sleep apnea (CSA), typically characterized by Cheyne-Stokes breathing (CSB), is increasingly found in patients with HF compared to the general population. An important pathogenetic factor of CSA seen in HF patients is an instability in the control of the respiratory system, characterized by both hypocapnia and increased chemosensitivity. Sympathetic overactivation, pulmonary congestion and increased chemosensitivity associated with HF stimulate the pulmonary vagal irritant receptor, resulting in chronic hyperventilation and hypocapnia. Additionally, the repetitive apnea and arousal cycles induce cyclic sympathetic activation, which may worsen the cardiac prognosis. Correcting CSB may improve both patient’s quality of life and HF syndrome itself. However, a treatment for HF in patients also experiencing CSA is yet to be found. In fact, conflicting results from numerous clinical studies investigating sleep apnea with HF guide to a troubling question, that is whether (or not) sleep apnea should be treated in patients with HF? This editorial attempts to both collect the current evidence about randomized control trials investigating CSA in patients with HF and highlight the effect of specific CSA treatments on cardiovascular endpoints.     

Sleep-disordered breathing in patients with decompensated heart failure

Sleep-disordered breathing (SDB) has a higher prevalence in patients with heart failure than in the general middle-aged population. Obstructive sleep apnea (OSA), one of the forms of SBD, promotes poorly controlled hypertension, coronary events, and atrial fibrillation events that can lead to acutely decompensated heart failure (ADHF), and evidence suggests that untreated OSA increases mortality in patients with heart failure. Cheyne–Stokes respiration and central sleep apnea (CSA) have long been associated with heart failure and, in many patients, can coexist with OSA. In this article, we propose a systematic approach to diagnose and treat OSA in patients with ADHF based on current evidence.     

Reliability and accuracy of sleep apnea scans in novel cardiac resynchronization therapy devices: an independent report of two cases

Pacemaker apnea scan algorithms are able to screen for sleep apnea. We investigated whether these systems were able to accurately detect sleep-disordered breathing (SDB) in two patients from an outpatient clinic. The first patient suffered from ischemic heart failure and severe central sleep apnea (CSA) and underwent adaptive servoventilation therapy (ASV). The second patient suffered from dilated cardiomyopathy and moderate obstructive sleep apnea (OSA). Pacemaker read-outs did not match polysomnography (PSG) recordings well and overestimated the apnea–hypopnea index. However, ASV therapy-induced SDB improvements were adequately recognized by the apnea scan of the Boston Scientific INVIVE® cardiac resynchronization therapy pacemaker. Detection of obstructive respiratory events using impedance-based technology may underestimate the number of events, as frustrane breathing efforts induce impedance changes without significant airflow. By contrast, in the second case, apnea scan overestimated the number of total events and of obstructive events, perhaps owing to a very sensitive but less specific hypopnea definition and detection within the diagnostic algorithm of the device. These two cases show that a pacemaker apnea scan is able to reflect SDB, but PSG precision is not met by far. The device scan revealed the decline of SDB through ASV therapy for CSA in one patient, but not for OSA in the second case. To achieve reliable monitoring of SDB, further technical developments and clinical studies are necessary.     

Sleep-disordered breathing in acute decompensated heart failure

Sleep-disordered breathing (SDB), including obstructive sleep apnea (OSA) and central sleep apnea (CSA), is highly prevalent and frequently unrecognized in patients with chronic heart failure (HF). Untreated SDB may worsen acute decompensation of HF and delay recovery by increasing vascular inflammation and oxidative stress, impeding control of the blood pressure, and promoting arrhythmias. Untreated OSA doubles the risk for developing HF, and patients with HF who develop OSA are thought to have a worse prognosis than patients with HF alone. Similar to the findings in the general population, treatment of OSA appears to reduce cardiovascular morbidity and mortality in HF. The presence of CSA is associated with increased mortality in HF patients. Efficacious suppression of central sleep apnea with continuous positive airway pressure therapy may reduce mortality in HF.