Severe obstructive sleep apnea elicits concentric left ventricular geometry

The effect of continuous positive airway pressure therapy on atrial fibrillation in patients with obstructive sleep apnea

Obstructive sleep apnea (OSA) stands as an autonomous risk factor for a broad spectrum of cardiovascular diseases, particularly atrial fibrillation (AF), which is closely associated with heightened morbidity and mortality rates. The intricate pathophysiological pathways linking OSA to AF encompass chronic intermittent hypoxia, disruptions in the autonomic nervous system, inflammatory responses, and alterations in ion channel function. Continuous positive airway pressure (CPAP) therapy emerges as the frontline treatment for moderate to severe OSA, effectively alleviating symptomatic manifestations and potentially mitigating cardiovascular risks. However, the influence of CPAP on AF among OSA patients remains a subject of debate. Some investigations underscore its beneficial effects, including the reversal of atrial remodeling, enhanced atrial conduction, decreased AF incidence, and improved outcomes post-AF ablation in CPAP-treated individuals. Conversely, other studies reveal neutral or insignificant impacts. This review delves into the repercussions of CPAP therapy on AF in OSA patients, exploring potential explanations for the discrepancies observed across existing research endeavors. By consolidating current evidence and pinpointing areas ripe for further inquiry, this review aspires to inform clinical decision-making regarding the management of OSA-related AF.

Association of the TNF-α-308G>A gene polymorphism with left ventricular geometry and functional abnormalities in obstructive sleep apnea subjects

OBJECTIVE

Tumor necrosis factor-α (TNF-α) can induce left ventricular remodeling. In this study, we investigated whether the TNF-α-308G>A polymorphism is associated with left ventricular geometry (LVG) and left ventricular functional abnormalities in obstructive sleep apnea (OSA) subjects.

METHODS

Two hundred and seventy-eight subjects were enrolled. Echocardiography and genetic data were assessed in all patients. Geometric patterns of the left ventricle were determined from the relative wall thickness and left ventricular mass index (LVMI). Genetic analysis for the TNF-α-308G>A SNP rs1800629 was identified by Sanger sequencing. The correlations of the TNF-α-308G>A polymorphism with LVG and left ventricular function were analyzed by difference analysis and logistic regression.

RESULTS

The chi-square test showed that there were differences in genotype distributions among the four groups (p = 0.033), such that the frequency of GA+AA genotypes was significantly higher in the concentric hypertrophy group than in the normal geometry group (p < 0.05). Independent sample T tests showed that the GA+AA genotypes had higher IVST, LVPWT, LVMI, E/e' values, and lower e' values than those of the GG genotype (p < 0.05). Logistic regression analysis showed that the TNF-α-308G>A polymorphism was independently correlated with eccentric hypertrophy (OR = 2.456, p = 0.047) and concentric hypertrophy (OR = 2.456, p = 0.047).

CONCLUSION

In OSA patients, the TNF-α-308G>A polymorphism was linked to LVG and abnormal left ventricular diastolic function, suggesting that the TNF-α-308G>A polymorphism may have an important influence on LVG alterations.

Serum uric acid is related to left ventricular geometry and function in patients with obstructive sleep apnea

INTRODUCTION

Serum uric acid (SUA) is an oxidative stress-related biomarker of cardiovascular risk. We sought to discover whether or not SUA was related to left ventricular geometry (LVG) and function among individuals with obstructive sleep apnea (OSA).

METHODS

Patients with OSA and healthy controls were assessed for clinical features, echocardiography, polysomnography, and blood biochemical data. Patients with OSA were divided into four groups: normal geometry (NG), concentric remodeling (CR), eccentric hypertrophy (EH), and concentric hypertrophy (CH). Correlations of SUA with left ventricular (LV) structure and function were examined through Pearson correlation analysis. The risk variables of LVG were investigated using a multivariate logistic regression model.

RESULTS

Compared to controls, patients with OSA had greater SUA levels. The eccentric hypertrophy (EH) and concentric hypertrophy (CH) groups showed substantially greater SUA levels than the normal geometry (NG) and concentric remodeling (CR) groups (p < 0.05). SUA correlated positively with left ventricular mass index (LVMI) and relative wall thickness (RWT) but negatively with the E/A ratio, according to the Pearson correlation analysis. SUA independently affected EH (OR = 1.021, 95%CI = 1.015-1.028, p < 0.001) and CH (OR = 1.034, 95%CI = 1.025-1.043, p < 0.001) in patients with OSA by the multivariate logistic regression model.

CONCLUSIONS

Patients with OSA had elevated levels of SUA, which were seen to be closely linked with abnormal LVG and function. The findings suggest that SUA may raise the risk of LV structural and functional impairment in patients with OSA.

The impact of the Adenotonsillectomy on cardiac functions and oxidative stress

OBJECTIVE

Obstructive sleep apnea syndrome (OSAS) causes cardiovascular comorbidities and increased oxidative stress. Adenotonsillectomy is the first treatment option for OSAS secondary to adenotonsillar hypertrophy (ATH). This study evaluated the presence of cardiovascular changes, hypertension and oxidative stress before and after adenotonsillectomy in patients with OSAS secondary to ATH.

METHODS

Patients with ATH diagnosed with OSAS by polysomnography (PSG) were included. All participants received an Echocardiography (ECHO) and 24-h ambulatory blood pressure measurement (ABPM). Serum malonyldialdehyde (MDA) and total oxidant activity (TOS) levels of oxidant parameters; total antioxidant activity (TAS), catalase (CAT), superoxide dismutase (SOD) and glutathione (GSH) levels of antioxidant parameters were measured. All patients received an adenotonsillectomy. Postoperative evaluation was performed at the 6th month. In the postoperative period, PSG, ECHO, ABPM and the oxidant-antioxidant parameter levels in the serum was repeated.

RESULTS

Twenty-eight patients (13 males, 15 females; mean age 8.2 ± 2.06 years) were included in the study. In the preoperative period, concentric remodeling was observed in 14,8% of the patients, although they had no cardiovascular system complaints. The apnea-hypopnea index (AHI) scores were classified as mild in 39.3% (n = 11), moderate in 21.4% (n = 6) and severe in 39.3% (n = 11) preoperatively. In the postoperative period, 22 patients were evaluated. It was observed that the severity of OSAS decreased, ventricular functions improved, oxidant parameters decreased and antioxidant parameters increased postoperatively.

CONCLUSION

Adenotonsillectomy provides a positive change in cardiovascular system parameters and an antioxidant change in the oxidative balance in patients with OSAS.

Obstructive sleep apnea increases the risk of cardiovascular damage: a systematic review and meta-analysis of imaging studies

BACKGROUND

We aimed to perform a systematic review and meta-analysis of the association between obstructive sleep apnea (OSA) and cardiac as well as coronary impairment evaluated using imaging modalities. Finding of this study will provide more robust evidence regarding OSA-induced cardiovascular damage.

METHODS

We systematically searched through PubMed, EMBASE, and Cochrane library databases for relevant literatures on the association between OSA and cardiovascular damage evaluated using imaging modalities, and manually searched the references of selected articles for additional relevant articles. For each clinical parameter relevant to the meta-analysis, we first evaluated the methodological heterogeneity of the relevant studies and thereafter pooled the data together using fixed effect or random effect model. The difference in the relevant indices of cardiovascular damage between OSA patients and controls was evaluated using the standardized mean difference.

RESULTS

Of the 82 articles included in the final systematic analysis, 20 studies explored the association between OSA and coronary atherosclerosis. OSA patients had higher rate of coronary atherosclerosis assessed by coronary artery calcification score and plaque volume. Moreover, the severity of OSA and coronary atherosclerosis displayed a positive correlation. The rest of the studies (n = 62) evaluated cardiac alterations in OSA patients. According to the inclusion and exclusion criteria, 46 studies yielding 3082 OSA patients and 1774 controls were pooled for the meta-analysis. For left cardiac structure and function, OSA patients exhibited significantly wider left atrial diameter; higher left atrium volume index; wider left ventricular end-systolic diameter, left ventricular end-diastolic diameter, and left ventricular mass; higher left ventricular mass index; wider interventricular septum diameter and posterior wall diameter; and higher left ventricular myocardial performance index (all p < 0.05). In addition, compared with controls, left ventricular ejection fraction was significantly decreased in OSA patients (p = 0.001). For right cardiac structure and function, OSA patients displayed a significant increase in right ventricular diameter and right ventricular myocardial performance index (both p < 0.001). Finally, compared with controls, OSA patients displayed significant decrease in tricuspid annular plane systolic excursion and RV fractional area change (p = 0.001).

CONCLUSION

Overall, this systematic review and meta-analysis provides imaging evidence in support that OSA patients are at a higher risk of developing coronary atherosclerosis and display cardiac remodeling and dysfunction.

Obstructive sleep apnoea syndrome and left ventricular hypertrophy: a meta-analysis of echocardiographic studies

AIM

We investigated the association between obstructive sleep apnoea (OSA) and subclinical cardiac organ damage through a meta-analysis of echocardiographic studies that provided data on left ventricular hypertrophy (LVH), assessed as a categorical or continuous variable.

DESIGN

The PubMed, OVID-MEDLINE, and Cochrane library databases were systematically analyzed to search English-language articles published from 1 January 2000 to 15 August 2019. Studies were detected by using the following terms: 'obstructive sleep apnea', 'sleep quality', 'sleep disordered breathing', 'cardiac damage', 'left ventricular mass', 'left ventricular hypertrophy', and 'echocardiography'.

RESULTS

Meta-analysis included 5550 patients with OSA and 2329 non-OSA controls from 39 studies. The prevalence of LVH in the pooled OSA population was 45% (CI 35--55%). Meta-analysis of studies comparing the prevalence of LVH in participants with OSA and controls showed that OSA was associated with an increased risk of LVH (OR = 1.70, CI 1.44-2.00, P < 0.001). LV mass was significantly increased in patients with severe OSA as compared with controls (SMD 0.46 ± 0.08, CI 0.29-0.62, P < 0.001) or with mild OSA. This was not the case for studies comparing patients with unselected or predominantly mild OSA and controls (0.33 ± 0.17, CI -0.01 to 0.67, P = 0.057).

CONCLUSION

The present meta-analysis expands previous information on the relationship between OSA and echocardiographic LVH, so far based on individual studies. The overall evidence strongly suggests that the likelihood of LVH increases with the severity of OSA, thus exhibiting a continuous relationship.

Obesity cardiomyopathy: evidence, mechanisms, and therapeutic implications

The prevalence of heart failure is on the rise and imposes a major health threat, in part, due to the rapidly increased prevalence of overweight and obesity. To this point, epidemiological, clinical, and experimental evidence supports the existence of a unique disease entity termed “obesity cardiomyopathy,” which develops independent of hypertension, coronary heart disease, and other heart diseases. Our contemporary review evaluates the evidence for this pathological condition, examines putative responsible mechanisms, and discusses therapeutic options for this disorder. Clinical findings have consolidated the presence of left ventricular dysfunction in obesity. Experimental investigations have uncovered pathophysiological changes in myocardial structure and function in genetically predisposed and diet-induced obesity. Indeed, contemporary evidence consolidates a wide array of cellular and molecular mechanisms underlying the etiology of obesity cardiomyopathy including adipose tissue dysfunction, systemic inflammation, metabolic disturbances (insulin resistance, abnormal glucose transport, spillover of free fatty acids, lipotoxicity, and amino acid derangement), altered intracellular especially mitochondrial Ca²⁺ homeostasis, oxidative stress, autophagy/mitophagy defect, myocardial fibrosis, dampened coronary flow reserve, coronary microvascular disease (microangiopathy), and endothelial impairment. Given the important role of obesity in the increased risk of heart failure, especially that with preserved systolic function and the recent rises in COVID-19-associated cardiovascular mortality, this review should provide compelling evidence for the presence of obesity cardiomyopathy, independent of various comorbid conditions, underlying mechanisms, and offer new insights into potential therapeutic approaches (pharmacological and lifestyle modification) for the clinical management of obesity cardiomyopathy.

Left ventricular hypertrophy predicts poorer cardiovascular outcome in normotensive normoglycemic patients with rheumatoid arthritis

INTRODUCTION

Patients with rheumatoid arthritis (RA) develop early changes in left ventricular (LV) geometry and experience cardiovascular events in excess than in the general population. This study was designed to assess prevalence, predictors and prognostic role of LV hypertrophy (LVH) in a selected group of RA patients with normal blood pressure and glycemia who should be at low risk for LVH.

METHODS

We prospectively analyzed 241 normotensive normoglycemic RA patients (mean age 53 ± 12 years, 61% women) involved in a primary prevention program for cardiovascular diseases who were followed-up for 40 (24-56) months. LVH was detected by echocardiography and defined as LV mass ≥49.2 g/m^2.7 for men and ≥46.7 g/m^2.7 for women. Primary outcome was a composite of cardiovascular death/hospitalization.

RESULTS

LVH was detected in 39 patients (16%). Older age (>53 years), greater body mass index (BMI > 25 kg/m² ), longer duration of RA disease, anti-cyclic citrullinated peptide antibody (ACPA) positivity and concentric LV geometry were the variables associated with LVH. During the follow-up, a cardiovascular event occurred in 12 of 39 (31%) patients with LVH and in 22 of 202 (11%; P < .001) patients without LVH. LVH independently predicted cardiovascular events (hazards ratio 3.28 [95% CI 1.03-9.20], P = .03) at Cox regression analysis together with C-reactive protein and ACPA positivity.

CONCLUSIONS

Nearly one-sixth of normotensive normoglycemic RA patients analyzed in a primary prevention program for cardiovascular diseases has LVH which is associated with obesity and older age, and strongly predicts cardiovascular event in these subjects.

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.

Targeting Concentric Left Ventricular Hypertrophy in Obstructive Sleep Apnea Syndrome. A Meta-analysis of Echocardiographic Studies

AIM

We assessed the association between obstructive sleep apnea (OSA) and left ventricular hypertrophy (LVH) subtypes (i.e., concentric and eccentric LVH) trough a meta-analysis of echocardiographic studies.

DESIGN

The PubMed, OVID-MEDLINE, and Cochrane library databases were systematically analyzed to search full papers published from 1st January 2000 to 31st August 2019. Studies were detected by using the following terms: "obstructive sleep apnea", "sleep disordered breathing", "left ventricular mass", "left ventricular geometry", "left ventricular hypertrophy", "echocardiography".

RESULTS

Meta-analysis included 1,760 patients with OSA and 1,284 non-OSA controls from 9 studies. The prevalence rates of concentric and eccentric LVH in the pooled OSA population were 24.0% (confidence interval [CI] 16.0-33.0%) and 16.0% (CI 12.0-23.0%), respectively. Meta-analysis of six studies comparing the prevalence of LVH subtypes in participants with OSA and controls showed that OSA was associated with an increased risk of both concentric (odds ratio [OR] = 1.62, CI: 1.27-2.07, P < 0.0001) and eccentric (OR = 1.34, CI: 1.07-1.67, P < 0.009) LVH, respectively.

CONCLUSIONS

Our findings suggest that in the OSA setting concentric LVH is more frequent than eccentric LVH. From a practical perspective, in consideration of the particularly adverse prognostic significance of concentric LVH, a comprehensive echocardiographic evaluation targeting LVH subtypes could improve cardiovascular risk stratification in patients with OSA.

The Effects of Eplerenone on the Circadian Blood Pressure Pattern and Left Ventricular Hypertrophy in Patients with Obstructive Sleep Apnea and Resistant Hypertension-A Randomized, Controlled Trial

The obstructive sleep apnea (OSA) is highly associated with various significant cardiovascular outcomes such as resistant hypertension (RAH). Despite this, as of now the relationship between high night-time blood pressure (BP) and left ventricular hypertrophy (LVH) in patients with OSA and RAH is not fully understood. The aim of this study was to assess the influence of the addition of eplerenone to a standard antihypertensive therapy on parameters of 24-h ambulatory blood pressure measurement (ABPM) as well as on the results of echocardiography and polysomnography in patients with OSA and RAH. The patients were randomly assigned to one of the two study groups: the treatment group, receiving 50 mg/d eplerenone orally for 6 months (n = 51) and the control group, remaining on their standard antihypertensive therapy (n = 51). After that period, a significant reduction in the night-time BP parameters in the treatment group including an increased night blood pressure fall from 4.6 to 8.9% was noted. Additionally, the number of non-dipper patients was reduced by 45.1%. The treatment group also revealed a decrease in left ventricular hypertrophy and in the apnea-hypopnea index (AHI) with a positive correlation being observed between these two parameters. This study is the first to report the improvement of the circadian BP profile and the improvement of the left ventricle geometry in patients with OSA and RAH following the addition of selective mineralocorticoid receptor antagonists to antihypertensive therapy.

Hypertensive Heart Disease and Obesity: A Review

Metabolic syndrome is an increasingly prevalent constellation of disease processes among the global population. Hypertension and obesity are among the contributing etiologies, and obesity increases the likelihood of hypertensive heart disease by creating a proinflammatory state, as well as increasing sympathetic tone and formation of reactive oxygen species. Hypertensive heart disease is characterized by myocardial fibrosis, which portends higher risk of developing reduced ejection fraction, diastolic dysfunction, ischemia, and arrhythmias, making early diagnosis and treatment essential to the prevention of cardiac events.

Cardiac rhythm disorders in obstructive sleep apnea

Obstructive sleep apnea (OSA) is common among patients with cardiac rhythm disorders. OSA may contribute to arrhythmias due to acute mechanisms, such as generation of negative intrathoracic pressure during futile efforts to breath, intermittent hypoxia, and surges in sympathetic activity. In addition, OSA may lead to heart remodeling and increases arrhythmia susceptibility. Atrial distension and remodeling, that has been shown to be associated with OSA, is a well-known anatomical substrate for atrial fibrillation (AF). AF is the arrhythmia most commonly described in patients with OSA. Several observational studies have shown that the treatment of OSA with continuous positive airway pressure (CPAP) reduces recurrence of AF after electrical cardioversion and catheter ablation. There is also evidence that nocturnal hypoxemia, a hallmark of OSA, predicts sudden cardiac death (SCD) independently of well-established cardiovascular risk factors. Among patients with an implantable cardiac defibrillator, those with OSA have a higher risk of receiving treatment for life-threatening arrhythmias. Nocturnal hypoxemia may also increase vagal tone, which increases susceptibility to bradycardic and conduction rhythm disorders that have also been described in patients with OSA. In conclusion, there are several biological pathways linking OSA and increased cardiac arrhythmogenesis propensity. However, the independent association is derived from observational studies and the direction of the association still needs clarification due to the lack of large clinical trials. This review focuses on the current scientific evidence linking OSA to cardiac rhythm disorders and point out future directions.

The association of sleep disordered breathing with left ventricular remodeling in CAD patients: a cross-sectional study

Background

There is still insufficient knowledge on the potential effect of mild to moderate sleep-disordered breathing (SDB) that is widely prevalent, often asymptomatic, and largely undiagnosed in patients with stable coronary artery disease (CAD). SDB affects 34% of men and 17% of women aged between 30 and 70. The objective of this study was to evaluate the association between SDB and left ventricular (LV) hypertrophy as well as structural remodeling in stable CAD patients.

Methods

The study was based on a cross-sectional design. Echocardiography and polysomnography was performed in 772 patients with CAD and with untreated sleep apnea. All study participants underwent testing by Epworth Sleepiness Scale questionnaire. Their mean age, NYHA and left ventricular ejection fraction were, respectively: 57 ± 9 years, 2.1 ± 0.5 and 51 ± 8%, and 76% were men. Sleep apnea (SA) was defined as an apnea-hypopnea-index (AHI) ≥5 events/h, and, non-SA, as an AHI <5.

Results

Sleep apnea was present in 39% of patients, and a large fraction of those patients had no complaints on excessive daytime sleepiness. The patients with SA were older, with higher body mass and higher prevalence of hypertension. LV hypertrophy (LVH), defined by allometrically corrected (LV mass/height^2.7) gender-independent criteria, was more common among the patients with SA than those without (86% vs. 74%, p < 0.001). The frequency of LVH by wall thickness criteria (interventricular septal thickness or posterior wall thickness ≥ 12 mm: 49% vs. 33%, p < 0.001) and concentric LVH (61% vs. 47%, p = 0.001) was higher in CAD patients with SA. The patients with SA had significantly higher values of both interventricular septal thickness and posterior wall thickness. Multiple logistic regression analysis showed that even mild sleep apnea was an independent predictor for LVH by wall thickness criteria and concentric LVH (OR = 1.5; 95% CI 1.04–2.2 and OR = 1.9; 1.3–2.9 respectively).

Conclusions

We concluded that unrecognized sleep apnea was highly prevalent among patients with stable CAD, and the majority of those patients did not report daytime sleepiness. Mild to moderate sleep apnea was associated with increased LV wall thickness, LV mass, and with higher prevalence of concentric LV hypertrophy independently of coexisting obesity, hypertension, diabetes mellitus or advancing age.

Prognostic Role of Subclinical Left Ventricular Systolic Dysfunction Evaluated by Speckle-Tracking Echocardiography in Rheumatoid Arthritis

BACKGROUND

Speckle-tracking echocardiography allows early detection of subclinical left ventricular systolic dysfunction (LVSD) in patients with rheumatoid arthritis (RA). In this prospective study, we assessed the prevalence and the prognostic role of subclinical LVSD detected by speckle-tracking echocardiography in RA patients.

METHODS

Two-dimensional global longitudinal strain (GLS) and global circumferential strain (GCS) were measured in 209 RA patients without overt cardiac disease. LVSD was defined as low GLS (> -16.0%), low GCS (> -17.8%), or both. The primary end point was all-causes hospitalization; the coprimary end point was hospitalization for cardiovascular causes.

RESULTS

The study population had a mean age of 58 ± 11 years; 67% were female, 52% had hypertension, and the RA duration was 14 ± 10 years. Low GLS was detected in 51 patients (24%), low GCS in 42 patients (20%), and combined low GLS and GCS in 18 patients (9%). During a median follow-up time of 16 months (range, 10-21 months), a primary end point occurred in 50 patients (24%), and 25 patients were hospitalized for a cardiovascular event. Multiple Cox regression analyses revealed that combined low GLS and GCS was independently associated with the end point defined as all-causes hospitalization together with higher aortic stiffness. Examined individually, neither low GCS nor low GLS showed an independent association with this typology of clinical outcome. Conversely, both low GCS and low GLS (examined individually or as combined low GLS and GCS) emerged as strong independent prognosticators of cardiovascular events.

CONCLUSIONS

Subclinical LVSD defined as low GLS, GCS, or both is common in RA patients without overt cardiac disease and provides additional prognostic information in these individuals.

OSA and Cardiac Arrhythmogenesis: Mechanistic Insights

A surge of data has reproducibly identified strong associations of OSA with cardiac arrhythmias. As an extension of epidemiologic and clinic-based findings, experimental investigations have made strides in advancing our understanding of the putative OSA and cardiac arrhythmogenesis mechanistic underpinnings. Although most studies have focused on the links between OSA and atrial fibrillation (AF), relationships with ventricular arrhythmias have also been characterized. Key findings implicate OSA-related autonomic nervous system fluctuations typified by enhanced parasympathetic activation during respiratory events and sympathetic surges subsequent to respiratory events, which contribute to augmented arrhythmic propensity. Other more immediate pathophysiologic influences of OSA-enhancing arrhythmogenesis include intermittent hypoxia, intrathoracic pressure swings leading to atrial stretch, and hypercapnia. Intermediate pathways by which OSA may trigger arrhythmia include increased systemic inflammation, oxidative stress, enhanced prothrombotic state, and vascular dysfunction. Long-term OSA-associated sequelae such as hypertension, atrial enlargement and fibrosis, ventricular hypertrophy, and coronary artery disease also predispose to cardiac arrhythmia. These factors can lead to a reduction in atrial effective refractory period, triggered and abnormal automaticity, and promote slowed and heterogeneous conduction; all of these mechanisms increase the persistence of reentrant arrhythmias and prolong the QT interval. Cardiac electrical and structural remodeling observed in OSA animal models can progress the arrhythmogenic substrate to further enhance arrhythmia generation. Future investigations clarifying the contribution of specific OSA-related mechanistic pathways to arrhythmia generation may allow targeted preventative therapies to mitigate OSA-induced arrhythmogenicity. Furthermore, interventional studies are needed to clarify the impact of OSA pathophysiology reversal on cardiac arrhythmogenesis and related adverse outcomes.

Nocturnal Intermittent Hypoxia Is Associated With Left Ventricular Hypertrophy in Middle-Aged Men With Hypertension and Obstructive Sleep Apnea

BACKGROUND

Obstructive sleep apnea (OSA) and left ventricular (LV) hypertrophy are considered to be closely associated. However, the relationship has not yet been fully demonstrated and is hence still controversial. The purpose of this study was to assess in hypertensive male patients the relationship between OSA and cardiac structure using a new index, namely, integrated area of desaturation (IAD), in addition to the apnea-hypopnea index (AHI) that is currently the most frequently used index of sleep-disordered breathing.

METHODS

In our cross-sectional study, 223 hypertensive men younger than 65 years with sleep apnea and normal cardiac function were enrolled. All subjects were evaluated by fully attended polysomnography. Cardiac structure and function were evaluated by echocardiography.

RESULTS

LV mass index significantly correlated with IAD (r = 0.203, P < 0.05), but not with AHI. Multivariate linear regression analyses showed that IAD, brain natriuretic peptide (BNP), and age are independent variables affecting the LV mass index (β = 0.262, 0.237, and 0.173, respectively, P < 0.05). IAD was the one and only determinant among the indices of sleep-disordered breathing.

CONCLUSIONS

Nocturnal intermittent hypoxia defined by IAD may be associated with LV hypertrophy in men with well-controlled hypertension and obstructive sleep apnea.

The association of metabolic syndrome with left ventricular mass and geometry in community-based hypertensive patients among Han Chinese

Background:

The association of metabolic syndrome (MS) with left ventricular (LV) hypertrophy is controversial. The objective of our study was to investigate the influence of MS on LV mass and geometry in community-based hypertensive patients among Han Chinese.

Materials and Methods:

This study included 1733 metabolic syndrome patients according to the International Diabetes Federation (IDF) definition and 2373 non-MS hypertension patients. LV hypertrophy was diagnosed by the criteria of LV mass ≥49.2 g/m^2.7 for men and 46.7 g/m^2.7 for women. LV geometric patterns (normal, concentric remodeling, concentric or eccentric hypertrophy) were calculated according to LV hypertrophy and relative wall thickness. Logistic regression analysis was used to determine odds ratio (OR) and 95% confidence interval (CI) of MS for LV hypertrophy and LV geometry abnormality.

Results:

The LV mass and LV mass index were higher in the MS group than in the non-MS group. In multiple adjusted models. LV mass index, LV mass, interventricular septum, and post wall were raised with the increased number of MS disorders. MS was associated with increased LV hypertrophy risk (unadjusted OR 1.38; 95% CI 1.21-1.57); age, sex, and blood pressure (BP; adjusted OR 1.39; 95% CI 1.22-1.59). MS was also associated with increased risk of eccentric hypertrophy in male and female patients. MS was only associated with increased risk of concentric hypertrophy in female patients; and MS was not associated with concentric remodeling.

Conclusion:

LV mass and LV mass index were associated with the increased number of MS disorders in the Chinese community-based hypertensive population. MS was not only associated with increased LV hypertrophy risk, but also associated with concentric and eccentric LV geometry abnormality, especially in females.

Obesity and hypertensive heart disease: focus on body composition and sex differences

There is evidence that hypertension is frequently associated with overweight/obesity even in kids and adolescents. Either conditions influence development of left ventricular (LV) hypertrophy (LVH), through different biological and hemodynamic mechanisms: obesity is conventionally thought to elicit a coherent growth of LV chamber dimensions and myocardial wall thickness (eccentric LV geometry), whereas a more accentuated increase in wall-thickness (concentric LV geometry) is attributed to hypertension. While during youth these differences are visible, proportion of LV concentric geometry, the most harmful LV geometric pattern, sharply raises in obese individuals during middle age, and becomes the most frequent geometric patterns among obese-hypertensive individuals. Two conditions with elevated hemodynamic impact, severe obstructive sleep apnea and masked hypertension contribute to the development of such a geometric pattern, but non-hemodynamic factors, and specifically body composition, also influence prevalence of concentric LV geometry. Contrasting a general belief, it has been observed that adipose mass strongly influences LV mass, particularly in women, especially when fat-free mass is relatively deficient. Thus, though blood pressure control is mandatory for prevention and reduction of LVH in obese hypertensive patients, without reduction of visceral adiposity regression of LVH is difficult. Future researches should be addressed on (1) assessing whether LVH resulting from alteration of body composition carries the same prognosis as pressure overload LVH; (2) defining tissue characterization of the hypertrophic heart in obese-hypertensive patients; (3) evaluating whether assessment of hemodynamic loading conditions and biological markers can help defining management of the association of obesity with hypertension.

Tissue Doppler Imaging predicts central sleep apnea in patients with chronic heart failure: data from the Daunia Registry

BACKGROUND

Tissue Doppler imaging (TDI) is used to improve risk stratification in patients with chronic heart failure (CHF). So far, few studies have used this method to investigate the characteristics of subjects with CHF and Cheyne-Stokes breathing (CSB). The aim of this study was therefore to evaluate whether TDI assessment may predict the presence of CSB in patients with CHF.

MATERIALS AND METHODS

A total of 41 consecutive patients with CHF enrolled in the Daunia Heart Failure Registry underwent echocardiography assessment and nocturnal polygraphy to evaluate the presence of sleep apnea and CSB. Conventional echocardiography and TDI parameters were calculated. We have also quantified by TDI a combined index (EAS index) of diastolic and systolic performance: E'/(A' × S').

RESULTS

Subjects with evidence of CSB (N = 8) were characterized by lower values of A' (5·03 ± 2·64 vs. 7·88 ± 2·64 cm/s, P < 0·01). A' and EAS index values were related to Cheyne-Stokes episode rates (r = -0·49 and 0·52, P < 0·05 and <0·01 respectively), EAS index values also with the number of episodes of central apnea (r = 0·39, P < 0·05). A' values predicted the presence of CSB at poly-somnography examination with an OR 0·62 (95% CI 0·40-0·96, P < 0·05) even after correction for age and gender.

CONCLUSIONS

Tissue Doppler imaging values (A') are associated with the presence of sleep apnea at nocturnal polygraphy.

Delayed neutrophil apoptosis mediates intermittent hypoxia-induced progressive heart failure in pressure-overloaded rats

BACKGROUND AND OBJECTIVE

Obstructive sleep apnea (OSA) and heart failure (HF) are common coexisting diseases. Intermittent hypoxia (IH), caused by repeated apnea/hypopnea events, accompanied by increased systemic inflammation, might contribute to the promotion of HF.

METHODS

To assess the hypothesis, rats were exposed to IH or normal air condition 4 weeks on the basis of normal heart function or pre-existing HF, which was induced by pressure overload caused by abdominal aortic constriction surgery performed 12 weeks earlier. Echocardiography was performed before and after IH exposure to evaluate left ventricular (LV) function. Serum concentrations of pro-inflammatory cytokines TNF-α and IL-6 were detected by enzyme-linked immunosorbent assay. Flow cytometric analysis was used to determine the apoptotic rate of polymorphonuclear neutrophils (PMNs).

RESULTS

The echocardiographic study showed a significant decrease in LV fractional shortening (FS) and ejection fraction (EF) as well as an increase in the LV relative wall thickness (RWT) index in HF rats, which was aggravated by further exposure to IH compared with single-handed HF-only and sham-IH and sham-control groups. A reduced PMN apoptotic rate was observed in HF-IH rats compared with HF-only, sham-IH, and sham-control rats. Serum concentrations of TNF-α and IL-6 were also increased in HF-IH rats, accompanied by delayed PMN apoptosis, indicating significant systemic inflammation induced by IH.

CONCLUSION

The results of this study demonstrated that IH aggravates LV remodeling and heart dysfunction in rats with pre-existing HF. Delayed neutrophil apoptosis, which was revealed in HF rats following exposure to IH, contributed to the exacerbation of myocardial damage and progression of heart dysfunction.

Determinants of concentric left ventricular hypertrophy in patients with resistant hypertension: RESIST-POL study

Left ventricular hypertrophy, especially concentric hypertrophy, has been shown to be an independent factor of cardiovascular diseases in patients with hypertension. Obstructive sleep apnea (OSA) and/or metabolic syndrome (MS) are common in patients with resistant hypertension (RHTN). The aim of this study was to evaluate factors associated with concentric hypertrophy in patients with RHTN. Data from 155 patients (92M, 63F) was analyzed. All patients underwent a thorough examination including: biochemical evaluations, ambulatory blood pressure monitoring, polysomnography and echocardiography. MS was defined by The Adult Treatment Panel III. Clinically significant OSA was defined as apnea/hypopnea index (AHI)>15 events per hour. Left ventricular mass index (LVMI) and relative wall thickness (RWT) were calculated. Four types of LV geometry were distinguished based on the LVMI and RWT. Patients were divided into four groups based on the LV geometric patterns: group 1 (normal geometry) (n=38, 24.4%); group 2 (concentric remodeling) (n=40, 25.8%); group 3 (eccentric hypertrophy) (n=26, 16.8%); and group 4 (concentric hypertrophy) (n=51, 33%). MS was found in 64% and OSA (AHI>15) in 43.2% of patients. Factors independently associated with concentric hypertrophy were: age (OR-1.51; 95% CI-1.00-2.27; P<0.04), OSA>15 events per hour (OR-2.73; 95% CI-1.26-5.93; P=0.01) and nighttime systolic blood pressure (SBP) (OR-1.69; 95% CI-1.32-2.17; P=0.0001). Concentric hypertrophy was the most common type of left ventricular disorder in patients with RHTN. Nighttime SBP and clinically significant OSA were independently associated with concentric hypertrophy in patients with RHTN.

Correlation of Left Ventricular Diastolic Function and Left Ventricular Geometry in Patients with Obstructive Sleep Apnoea Syndrome

BACKGROUND

The aim of this study is to evaluate the correlation of the left ventricular diastolic function and the left ventricular geometry in patients with obstructive sleep apnoea syndrome (OSAS) by echocardiography.

METHODS

The 181 patients diagnosed with OSAS were divided into the normal geometry group (NG), the concentric remodelling group (CR), the eccentric hypertrophy group (EH) and the concentric hypertrophy group (CH). Pearson correlation analysis and multiple linear regression analysis were performed toward the correlation of the left ventricular diastolic function and the left ventricular geometry.

RESULTS

The E peak in the EH and CH group was significantly reduced, with significant difference; the E/A, Em, Am and Em/Am was reduced in the order of the CR, EH and CH groups, while E/Em was increased, and the difference was significant. Pearson correlation analysis revealed that the Em/Am showed significant negative correlations with the left ventricular mass index (LVMI) [r = -0.419] and relative wall thickness (RWT) [r = -0.289], while the E/Em was significantly positively correlated with the LVMI (r = 0.638) and RWT [r = 0.328] (p < 0.001). Multiple linear regression analysis revealed that LVMI and RWT had influence on the Em/Am and E/Em (r2 = 0.402, r2 = 0.107, p < 0.001). The left ventricular diastolic dysfunction was the worst in the CH group.

CONCLUSIONS

There was correlation between the left ventricular diastolic dysfunction and the changes in cardiac geometry.

Independent association of obstructive sleep apnea with left ventricular geometry and systolic function in resistant hypertension: the RESIST-POL study

OBJECTIVE

We investigated the impact of obstructive sleep apnea (OSA) and night blood pressure (BP) on left ventricular geometry and systolic function in patients with resistant hypertension (RHTN).

METHODS AND RESULTS

Data from 155 patients with RHTN were analyzed. All patients underwent biochemical evaluations, ambulatory blood pressure monitoring (ABPM), and polysomnography. Left ventricular mass index (LVMI), relative wall thickness (RWT), left ventricular ejection fraction (LVEF), midwall fractional shortening (mwFS) and global longitudinal strain (GLS) were measured. Patients were divided into four groups based on the presence of metabolic syndrome (MS) and OSA: group 1: OSA(-), MS(-) [n = 42]; group 2: OSA(+), MS(-) [n = 14]; group 3: OSA(-), MS(+) [n = 46]; and group 4: OSA(+), MS(+) [n = 53]. In group 3 and 4 concentric geometry was present in 53.2% and 79.6% respectively (P = 0.004). There were no differences in LVEF between groups. Group 3 and 4 had lower mwFS as compared with group 1 (16.40 ± 1.9 and 15.38 ± 2.2 vs 17.44 ± 1.9; P < 0.049 and P < 0.0001 respectively). Group 4 had significantly lower GLS as compared with group 1 (-12.64 ± 3.3 vs -15.59 ± 4.0; P < 0.001). In the multivariable analysis, factors independently associated with concentric geometry were age, nighttime SBP (OR -1.04; 95%Cl 1.019-1.082; P < 0.0001) and OSA (OR -3.97; 95%Cl 1.835-8.590; P < 0.0001). In the other multivariable analysis, factors independently associated with GLS were OSA (beta = 0.279; P = 0.001), and nighttime DBP (beta = 0.168; P = 0.048) whereas factors independently associated with mwFS were age, gender, nighttime SBP, concentric geometry, and metabolic syndrome.

CONCLUSIONS

In patients with true RHTN without diabetes concentric geometry and systolic dysfunction are independently associated with moderate and severe OSA and nighttime BP levels.

Obesity and sleep apnea are independently associated with adverse left ventricular remodeling and clinical outcome in patients with atrial fibrillation and preserved ventricular function

AIMS

Obesity is associated with the development of atrial fibrillation (AF), and both obesity and AF are independently associated with the development of heart failure with preserved ejection fraction. We tested the hypothesis that sleep apnea (SA) would have a body mass index (BMI) independent association with adverse left ventricular (LV) remodeling and clinical outcomes in patients with AF and preserved LV function.

METHODS AND RESULTS

From 720 consecutive patients with AF, 403 patients without myocardial disease (preserved LV function) were identified and followed up for 3.3 ± 1.5 years. The primary outcome was a combination of all-cause mortality/heart failure hospitalization. Left ventricular mass and LV mass-to-volume ratio were higher in patients with SA and obesity (P < .0001 for all). Body mass index (β per log = .47; P < .0001) and SA (β = .05; P = .045) were independently associated with LV mass index. Patients with treated SA had a lower LV mass index (but not LV mass-to-volume ratio) compared with untreated (P = .002). In a best overall multivariable model, SA therapy (β = -.129; P = .001) and BMI (β per log = .373; P = .0007) had opposing associations with LV mass index. Sleep apnea (hazard ratio [HR] = 2.94; P = .0004) and BMI (HR per 1 kg/m(2) = 1.08; P = .004) were associated with clinical outcome in unadjusted analysis. Only SA was associated with clinical outcome in a best overall multivariable model (HR = 2.14; P = .02).

CONCLUSION

Sleep apnea and obesity are independently associated with adverse LV remodeling and clinical outcomes in patients with preserved LV function, whereas continuous positive airway pressure therapy is associated with a beneficial effect on LV remodeling. Research investigating SA therapies in patients at high risk for LV remodeling and heart failure is warranted.

Relationship between obstructive sleep apnea and markers of cardiovascular alterations in never-treated hypertensive patients

We addressed a question if there is a relationship between severity of newly diagnosed obstructive sleep apnea (OSA) and markers of cardiovascular alterations in middle-aged untreated hypertensive patients. In 121 consecutive patients with never-treated essential hypertension (mean age 35.9±10.1 years; 97 men and 24 women) evaluation of office and ambulatory blood pressure (BP) measurements, metabolic syndrome (MS) components and markers of alterations in cardiovascular system including left ventricular structure and function, carotid artery wall intima-media thickness (cIMT) and urinary albumin excretion (UAE) was performed. OSA was classified as mild (apnea/hypopnea index (AHI) 5-15 events h(-1)) or moderate-to-severe (AHI >15 events h(-1)). Mild and moderate-to-severe OSA were diagnosed in 30% and 20% of patients, respectively. No differences in nighttime BP levels and decline between patients with and without OSA were observed. The patients with moderate-to-severe OSA were characterized by higher cIMT (0.74±0.16 vs. 0.60±0.15 mm; P=0.001), UAE (14.5±6.9 vs. 10.0±8.0 mg 24 h(-1); P=0.014), relative wall thickness (0.42±0.05 vs. 0.39±0.05; P=0.023) and by a higher degree of diastolic dysfunction (E'-wave velocity 11.4±3.2 vs. 15.5±3.8 m s(-1); P<0.001) as compared with the patients without OSA. In multivariate analysis, AHI independently of BP and MS components correlated with UAE, relative wall thickness and E'-wave velocity. In the middle-aged never-treated hypertensive patients, moderate-to-severe OSA correlates with markers of cardiovascular alterations independently of BP levels and MS components.

Left ventricular geometry in obesity: Is it what we expect?

Obesity is characterized by the disproportionate growth of the components of body size, including adipose tissue and lean body mass. Left ventricular (LV) hypertrophy often develops, due to the coexistence of hemodynamic (cardiac workload) and non-hemodynamic components (including body composition and activity of visceral fat). While the hypertrophy of cardiomyocytes is produced by the hemodynamic load, through sarcomeric replication, there is a parallel growth of non-muscular myocardial components, including interstitial fat infiltration and accumulation of triglycerides in the contractile elements, which are thought to influence LV geometric pattern. Thus, pure intervention on hemodynamic load is unlikely to result in effective reduction of LV hypertrophy in obese. We review pathophysiology and prevalence of LV hypertrophy in obesity, with specific attention to LV geometric abnormalities and relations with body size.

Frequent periodic leg movement during sleep is associated with left ventricular hypertrophy and adverse cardiovascular outcomes

BACKGROUND

Sleep disturbance caused by obstructive sleep apnea is recognized as a contributing factor to adverse cardiovascular outcomes. However, the effect of restless legs syndrome, another common cause of fragmented sleep, on cardiac structure, function, and long-term outcomes is not known. The aim of this study was to assess the effect of frequent leg movement during sleep on cardiac structure and outcomes in patients with restless legs syndrome.

METHODS

In our retrospective study, patients with restless legs syndrome referred for polysomnography were divided into those with frequent (periodic movement index > 35/hour) and infrequent (≤ 35/hour) leg movement during sleep. Long-term outcomes were determined using Kaplan-Meier and logistic regression models.

RESULTS

Of 584 patients, 47% had a periodic movement index > 35/hour. Despite similarly preserved left ventricular ejection fraction, the group with periodic movement index > 35/hour had significantly higher left ventricular mass and mass index, reflective of left ventricular hypertrophy (LVH). There were no significant baseline differences in the proportion of patients with hypertension, diabetes, hyperlipidemia, prior myocardial infarction, stroke or heart failure, or the use of antihypertensive medications between the groups. Patients with frequent periodic movement index were older, predominantly male, and had more prevalent coronary artery disease and atrial fibrillation. However, on multivariate analysis, periodic movement index > 35/hour remained the strongest predictor of LVH (odds ratio, 2.45; 95% confidence interval, 1.67-3.59; P < .001). Advanced age, female sex, and apnea-hypopnea index were other predictors of LVH. Patients with periodic movement index > 35/hour had significantly higher rates of heart failure and mortality over median 33-month follow-up.

CONCLUSIONS

Frequent periodic leg movement during sleep is an independent predictor of severe LVH and is associated with increased cardiovascular morbidity and mortality.

Cardiovascular characteristics in subjects with increasing levels of abnormal glucose regulation: the Strong Heart Study

OBJECTIVE

To evaluate whether impaired fasting glucose (IFG) or the combination of IFG and impaired glucose tolerance (IGT) is associated with progressive abnormalities of cardiac geometry and function.

RESEARCH DESIGN AND METHODS

We studied 562 nondiabetic (311 women), nonhypertensive participants of the second Strong Heart Study exam, without prevalent cardiovascular (CV) disease and with estimated glomerular filtration rate ≥60 mL/min/1.73 m(2) (age 46-65 years, 198 with isolated IFG [35%], and 132 with combined IFG and IGT [23%]). Anthropometric parameters, insulin resistance, fibrinogen, C-reactive protein (CRP), lipid profile, blood pressure (BP), and echocardiographic parameters were compared with 232 participants with normal glucose tolerance (NGT).

RESULTS

BMI, prevalence of central obesity, homeostatic model assessment index of insulin resistance, plasma triglycerides, fibrinogen, and CRP increased progressively across categories of glucose intolerance (P < 0.0001), with the IFG+IGT group having higher values than those with isolated IFG (0.05 < P < 0.0001). Compared with NGT, both IFG and IFG+IGT exhibited greater left ventricular (LV) mass (P < 0.0001) and lower Doppler early peak rapid filling velocity to peak atrial filling velocity ratio (P < 0.005), without differences in LV systolic function. The odds of LV hypertrophy (LV mass index >46.7 in women or >49.2 g/m(2.7) in men) was 3.5 in IFG participants (95% CI 0.68-17.76; P = NS) and 9.76 (2.03-46.79; P = 0.004) in IFG+IGT, compared with NGT, after adjustment for age, sex, heart rate, systolic BP, and waist circumference (WC). In the overall sample, LV mass index was associated with WC (P = 0.033), CRP (P = 0.027), and 2-h oral glucose tolerance test (P = 0.001) independently of confounders.

CONCLUSIONS

Cardiometabolic profile and markers of inflammation are more severely altered in men and women with both IFG and IGT compared with those with IFG alone. These individuals, in the absence of hypertension, have a 10-fold greater probability of preclinical CV disease (LV hypertrophy).

The role of obesity and sleep apnea in atrial fibrillation

PURPOSE OF REVIEW

To discuss the relationship between obesity and obstructive sleep apnea as they relate to the growing atrial fibrillation epidemic, and to discuss possible mechanistic links and implications for treatment of atrial fibrillation.

RECENT FINDINGS

Increasing BMI plays an important role in development of atrial fibrillation in both men and women. Sleep-disordered breathing contributes to cardiac chamber enlargement, which may be responsible for increasing atrial fibrillation in this population. Patients with obstructive sleep apnea and/or obesity have less freedom from atrial fibrillation recurrence after catheter ablation for atrial fibrillation.

SUMMARY

BMI is a strong predictor of future development of atrial fibrillation and should be considered as a risk factor for atrial fibrillation. Patients with obstructive sleep apnea and/or obesity have high atrial fibrillation recurrence rates following atrial fibrillation ablation.

Effects of nasal continuous positive airway pressure on left ventricular concentric hypertrophy in obstructive sleep apnea syndrome

OBJECTIVE

Abnormal left ventricular (LV) geometry, especially concentric hypertrophy, is associated with cardiovascular morbidity and mortality. The aim of this study was to evaluate the impact of obstructive sleep apnea syndrome (OSAS) and the effects of nasal continuous positive airway pressure (CPAP) on the LV geometric patterns.

METHODS

The LV morphological parameters, including the LV mass index (LVMI) and the relative wall thickness (RWT), were evaluated using echocardiography in 37 patients with OSAS diagnosed on polysomnography and 34 control subjects. Based on the values of LVMI and RWT, the LV geometry was classified as normal, concentric remodeling, concentric hypertrophy or eccentric hypertrophy. The echocardiographic parameters were reassessed after three months of CPAP treatment.

RESULTS

Compared with the controls, the OSAS patients had a higher proportion of concentric hypertrophy patterns (54% vs. 0%, p<0.001) and a lower proportion of normal geometric patterns (5% vs. 62%, p<0.001). A univariate logistic regression analysis showed the apnea-hypopnea index, lowest oxygen saturation, hypoxemia index and body mass index to each be significantly associated with the presence of concentric hypertrophy. In a multivariate analysis of these factors, the apnea-hypopnea index was found to be a significant independent factor associated with the presence of concentric hypertrophy (odds ratio: 1.06, p=0.008). Three months of CPAP treatment resulted in significant decreases in LVMI and the proportion of cases with concentric hypertrophy (both p=0.025).

CONCLUSION

In our limited study population, OSAS patients were found to be associated with a high prevalence of concentric LV hypertrophy patterns that were able to be reversed with three months of CPAP treatment.