Obstructive sleep apnea in patients admitted for acute myocardial infarction. Prevalence, predictors, and effect on microvascular perfusion

Obstructive sleep apnoea and nocturnal atrial fibrillation in patients with ischaemic heart disease

INTRODUCTION

Arrhythmias, especially atrial fibrillation (AF) and ventricular arrhythmias, are independent risk factors of mortality in patients with ischaemic heart disease (IHD). While there is a growing body of evidence that suggests an association between obstructive sleep apnoea (OSA) and cardiac arrhythmias, evidence on this relationship in patients with IHD has been scant and inconsistent. We hypothesised that in patients with IHD, severe OSA is associated with an increased risk of nocturnal arrhythmias.

METHODS

We studied 103 consecutive patients with IHD who underwent an overnight polysomnography. Exposed subjects were defined as patients who had an apnoea-hypopnoea index (AHI) ≥30/h (severe OSA), and nonexposed subjects were defined as patients who had an AHI <30/h (nonsevere OSA). All electrocardiograms (ECGs) were interpreted by the Somte ECG analysis software and confirmed by a physician blinded to the presence or absence of exposure. Arrhythmias were categorised as supraventricular and ventricular. Arrhythmia subtypes (ventricular, atrial and conduction delay) were analysed as dichotomous outcomes using multiple logistic regression models.

RESULTS

Atrial fibrillation and AF/flutter (odds ratio 13.5, 95% confidence interval 1.66-109.83; P = 0.003) were found to be more common in the severe OSA group than in the nonsevere OSA group. This association remained significant after adjustment for potential confounders. There was no significant difference in the prevalence of ventricular and conduction delay arrhythmias between the two groups.

CONCLUSION

In patients with IHD, there was a significant association between severe OSA and nocturnal AF/flutter. This underscores the need to evaluate for OSA in patients with IHD, as it may have important implications on clinical outcomes.

Clinical outcomes of obstructive sleep apnea in patients with acute coronary syndrome in relation to hyperuricemia status

The clinical outcome of obstructive sleep apnea in patients with acute coronary syndrome in relation to hyperuricemia is still unclear. We aimed to explore the clinical prognosis of obstructive sleep apnea in patients with acute coronary syndrome in relation to hyperuricemia status. This was a prospective cohort study. We included consecutively eligible patients with acute coronary syndrome who underwent cardiorespiratory polygraphy between June 2015 and January 2020. According to apnea-hypopnea index ≥ 15 events per hr and serum uric acid level, the population was divided into four groups: hyperuricemia with obstructive sleep apnea; hyperuricemia with non-obstructive sleep apnea; no hyperuricemia with obstructive sleep apnea; and no hyperuricemia with non-obstructive sleep apnea. The primary endpoint was major adverse cardiovascular and cerebrovascular events, including cardiovascular death, myocardial infarction, stroke, ischaemia-driven revascularization, and readmission for unstable angina or heart failure. Spearman correlation analysis and Cox regression model were mainly used to estimate the data. The median follow-up was 2.9 years. Among 1925 patients with acute coronary syndrome, 29.6% had hyperuricemia and 52.6% had obstructive sleep apnea. Uric acid was negatively correlated with minimum arterial oxygen saturation and mean arterial oxygen saturation, and positively correlated with apnea-hypopnea index, oxygen desaturation index and the duration of time with arterial oxygen saturation < 90% (p < 0.001). During 2.9 (1.5, 3.6) years of follow-up, obstructive sleep apnea was associated with an increased risk of major adverse cardiovascular and cerebrovascular events in patients with hyperuricemia (23.5% versus 13.4%; adjusted hazard ratio: 1.834; 95% confidence interval: 1.192-2.821, p = 0.006), but not in patients without hyperuricemia (21.9% versus 19.2%; adjusted hazard ratio: 1.131; 95% confidence interval: 0.880-1.453, p = 0.336). There was a correlation between uric acid levels and sleep respiratory indicators. Obstructive sleep apnea was associated with increased risk of major adverse cardiovascular and cerebrovascular events in patients with acute coronary syndrome with hyperuricemia, but not in patients without hyperuricemia.

Sex-Specific Associations of Obstructive Sleep Apnea Risk With Patient Characteristics and Functional Outcomes After Acute Myocardial Infarction: Evidence From the VIRGO Study

Background Though associations between obstructive sleep apnea (OSA) and cardiovascular outcomes are well described, limited data exist regarding the impact of OSA on sex-specific outcomes after acute myocardial infarction (AMI). Methods and Results The VIRGO (Variation in Recovery: Role of Gender on Outcomes of Young AMI Patients) study enrolled 3572 adults aged 18 to 55 years with AMI from the United States and Spain during 2008 to 2012. We included patients for whom the Berlin Questionnaire for OSA was scored at the time of AMI admission (3141; 2105 women, 1036 men). We examined the sex-specific association between baseline OSA risk with functional outcomes including health status and depressive symptoms at 1 and 12 months after AMI. Among both groups, 49% of patients were at high risk for OSA (1040 women; 509 men), but only 4.7% (148) of patients had a diagnosed history of OSA. Though patients with a high OSA risk reported worse physical and mental health status and depression than low-risk patients in both sexes, the difference in these functional outcomes was wider in women than men. Moreover, women with a high OSA risk had worse health status, depression, and quality of life than high-risk men, both at baseline and at 1 and 12 months after AMI. Conclusions Young women with a high OSA risk have poorer health status and more depressive symptoms than men at the time of AMI, which may place them at higher risk of poorer health outcomes over the year following the AMI. Further, the majority of patients at high risk of OSA are undiagnosed at the time of presentation of AMI.

Expression alteration of serum exosomal circular RNAs in obstructive sleep apnea patients with acute myocardial infarction

PURPOSE

Circular RNAs (circRNAs) are recently identified as a class of non-coding RNAs that participate in the incidence of acute myocardial infarction (AMI). However, circRNAs expression pattern in obstructive sleep apnea (OSA) with AMI remains unknown. The aim was to investigate circRNAs expression alteration in serum exosomes derived from OSA patients with AMI.

METHODS

The serum exosomal circRNAs profile of three healthy subjects, three OSA without AMI and three OSA with AMI were analyzed using high-throughput sequencing. Bioinformatic analyses were carried out to assess potential core circRNAs and functional analyses were conducted to study biological functions.

RESULTS

Compared to healthy subjects, there were 5225 upregulated and 5798 downregulated circRNAs in exosomes from OSA with AMI patients. And our study also identified 5210 upregulated and 5813 downregulated circRNAs in OSA with AMI patients compared to OSA without AMI. The differential expression of 2 circRNAs (hsa_circRNA_101147, hsa_circRNA_101561) between healthy subjects and OSA without AMI, and 4 circRNAs (hsa_circRNA_101328, hsa_circRNA_104172, hsa_circRNA_104640, hsa_circRNA_104642) between healthy subjects and OSA with AMI were confirmed by qRT-PCR. In addition, we demonstrated that miR-29a-3p targeted hsa_circRNA_104642 directly.

CONCLUSIONS

This study demonstrated that there were a number of dysregulated circRNAs in exosomes from OSA with AMI patients, which might be effectively served as a promising diagnostic biomarker and therapeutic targets.

Proteomic profiling for prediction of recurrent cardiovascular event in patients with acute coronary syndrome and obstructive sleep apnea: A post-hoc analysis from the ISAACC study

BACKGROUND

Obstructive sleep apnea (OSA) is associated with a recurrent cardiovascular event (CVE) risk in patients with a first acute coronary syndrome (ACS). However, the pathological pathways by which OSA promotes this deleterious role are unknown. We aim to explore the proteomic profile associated with OSA that promote the recurrent CVE risk in severe OSA patients with ACS without previous cardiovascular diseases.

METHODS

This post-hoc analysis from the ISAACC study (NCT01335087) included 86 patients admitted for ACS. Patients underwent respiratory polygraphy for the first 24-72 h to OSA diagnosis. We analyzed of 276 cardiovascular and inflammatory related proteins in baseline fasting plasma samples using proximity expression assay technology (Olink®, Sweden). Protein levels were compared between severe OSA patients with/without recurrent CVEs during follow-up. Random forest was conducted to select relevant proteins and generate a predictive model of recurrent CVE.

RESULTS

We included 86 patients (median age: 61 years, median BMI: 29.4 kg/m² and 86 % males) admitted for ACS with severe OSA (56 without recurrent CVE/30 with recurrent CVE). The plasma levels of 38 proteins were differentially expressed between groups. Additionally, 12 proteins had a significant association with respiratory polygraphy parameters. Three proteins discriminate with an AUC of 0.81 (95 % CI of 0.71-0.9) between severe OSA patients with and without recurrent CVE. These proteins were implicated in cell proliferation, communication and apoptosis, and regulation/response to the inflammatory and immune systems.

CONCLUSION

In ACS patients with severe OSA, a proteomic profile was associated with recurrent CVEs. This proteomic profile was correlated with specific OSA parameters from respiratory polygraphy. Proteomic profiling may provide an new direction for patient risk stratification and clinical management.

A systematic review on the association of sleep-disordered breathing with cardiovascular pathology in adults

Sleep-disordered breathing (SDB) is characterized by repeated breathing pauses during sleep. The prevalence of SDB varies widely between studies. Some longitudinal studies have found an association of SDB with incident or recurrent cardiovascular events. We sought to systematically describe the current data on the correlation between SDB and cardiovascular pathology. Studies were included if they were original observational population-based studies in adults with clearly diagnosed SDB. The primary outcomes include all types of cardiovascular pathology. We carried out pooled analyses using a random effects model. Our systematic review was performed according to the PRISMA and MOOSE guidelines for systematic reviews and was registered with PROSPERO. In total, 2652 articles were detected in the databases, of which 76 articles were chosen for full-text review. Fourteen studies were focused on samples of an unselected population, and 8 studies were focused on a group of persons at risk for SDB. In 5 studies, the incidence of cardiovascular pathology in the population with SDB was examined. In total, 49 studies described SDB in patients with cardiovascular pathology. We found an association between SDB and prevalent /incident cardiovascular disease (pooled OR 1.76; 95% CI 1.38–2.26), and pooled HR (95% CI 1.78; 95% CI 1.34–2.45). Notably, in patients with existing SDB, the risk of new adverse cardiovascular events was high. However, the relationship between cardiovascular disease and SDB is likely to be bidirectional. Thus, more large-scale studies are needed to better understand this association and to decide whether screening for possible SDB in cardiovascular patients is reasonable and clinically significant.

Increased diastolic blood pressure and apnea time contribute to the poor apnea and hypopnea index and life quality of primary snoring: a cohort study combined with external validation

Obstructive sleep apnea hypoventilation syndrome (OSAHS) is a common sleep breathing disorder closely associated with cardiovascular disease. However, the respiratory sleep and related cardiovascular parameters on the apnea and hypopnea index (AHI) and life quality of primary snoring are unclear. We launched a cohort study focused on the association between respiratory sleep and cardiovascular-related parameters and apnea and hypopnea index, incorporating data from 218 patients with primary snoring in our medical center between Jun 1, 2015, and Apr 1, 2016. Thirty patients from Sichuan Cancer Hospital were used for validation. Patients with longer apnea time were more likely to progress to higher AHI (> 30) than controls (OR = 5.66, 95% CI = [2.79, 11.97], p < 0.001). Similarly, if patients have a higher value of diastolic blood pressure, they will also have a higher AHI (> 30) (HR [95% CI] = 3.42 [1.14, 13.65], p = 0.043). According to multivariate analysis, longest apnea time, the mean percentage of SaO2, and neckline length were independent risk factors of overall survival. A predictive model developed based on these factors above yielded a favorable agreement (C-index = 0.872) on the calibration curve. Thirty patients conducted external validation from Sichuan Cancer Hospital, displaying an AUC of 0.833 (0.782-0.884). Increased diastolic blood pressure and apnea time affect AHI level. An AHI prediction model based on these factors above can help clinicians predict the risk of high AHI events.

Intermittent Hypoxia and Atherosclerosis: From Molecular Mechanisms to the Therapeutic Treatment

Intermittent hypoxia (IH) has a dual nature. On the one hand, chronic IH (CIH) is an important pathologic feature of obstructive sleep apnea (OSA) syndrome (OSAS), and many studies have confirmed that OSA-related CIH (OSA-CIH) has atherogenic effects involving complex and interacting mechanisms. Limited preventive and treatment methods are currently available for this condition. On the other hand, non-OSA-related IH has beneficial or detrimental effects on the body, depending on the degree, duration, and cyclic cycle of hypoxia. It includes two main states: intermittent hypoxia in a simulated plateau environment and intermittent hypoxia in a normobaric environment. In this paper, we compare the two types of IH and summarizes the pathologic mechanisms and research advances in the treatment of OSA-CIH-induced atherosclerosis (AS), to provide evidence for the systematic prevention and treatment of OSAS-related AS.

Sleep-Disordered Breathing Is Associated With Reduced Left Atrial Strain Measured by Cardiac Magnetic Resonance Imaging in Patients After Acute Myocardial Infarction

Aims

Sleep disordered breathing (SDB) is known to cause left atrial (LA) remodeling. However, the relationship between SDB severity and LA dysfunction is insufficiently understood and may be elucidated by detailed feature tracking (FT) strain analysis of cardiac magnetic resonance images (CMR). After myocardial infarction (MI), both the left ventricle and atrium are subjected to increased stress which may be substantially worsened by concomitant SDB that could impair consequential healing. We therefore analyzed atrial strain in patients at the time of acute MI and 3 months after.

Methods and Results

40 patients with acute MI underwent CMR and polysomnography (PSG) within 3–5 days after MI. Follow-up was performed 3 months after acute MI. CMR cine data were analyzed using a dedicated FT software. Atrial strain (ε) and strain rate (SR) for atrial reservoir ([ε_s]; [SR_s]), conduit ([ε_e]; [SR_e]) and booster function ([ε_a]; [SR_a]) were measured in two long-axis views. SDB was defined by an apnea-hypopnea-index (AHI) ≥15/h. Interestingly, LA ε_s and ε_e were significantly reduced in patients with SDB and correlated negative with AHI as a measure of SDB severity at both baseline and follow-up. Intriguingly, patients that exhibited a reduced AHI at follow-up were more likely to have developed improved atrial reservoir and conduit strain (linear regression, p=0.08 for ε_s and ε_e). Patients with improved SDB (ΔAHI < −5/h) exhibited a mean improvement of LA reservoir strain of +7.2 ± 8.4% whereas patients with SDB deterioration (ΔAHI> + 5/h) showed a mean decrease of −5.3 ± 11.0% (p = 0.0131). Similarly, the difference for LA conduit function was +4.8 ± 5.9% (ΔAHI < −5/h) vs −3.6 ± 8.8% (ΔAHI> +5/h). Importantly, conventional volumetric parameters for atrial function (LA area, LA volume index) did not correlate with AHI at baseline or follow-up.

Conclusion

Our results show that LA function measured by CMR strain but not by volumetry is impaired in patients with SDB during acute cardiac injury. Consistent with a mechanistic association, improvement of SBD at follow-up resulted in improved LA strain. LA strain measurement might thus provide insight into atrial function in patients with SDB.

Subclinical Changes in Cardiac Functional Parameters as Determined by Cardiovascular Magnetic Resonance (CMR) Imaging in Sleep Apnea and Snoring: Findings from UK Biobank

Background and Objectives: Obstructive sleep apnea (OSA) is a common disorder with an increased risk for left ventricular and right ventricular dysfunction. Most studies to date have examined populations with manifest cardiovascular disease using echocardiography to analyze ventricular dysfunction with little or no reference to ventricular volumes or myocardial mass. Our aim was to explore these parameters with cardiac MRI. We hypothesized that there would be stepwise increase in left ventricular mass and right ventricular volumes from the unaffected, to the snoring and the OSA group. Materials and Methods: We analyzed cardiac MRI data from 4978 UK Biobank participants free from cardiovascular disease. Participants were allocated into three cohorts: with OSA, with self-reported snoring and without OSA or snoring (n = 118, 1886 and 2477). We analyzed cardiac parameters from balanced cine-SSFP sequences and indexed them to body surface area. Results: Patients with OSA were mostly males (47.3% vs. 79.7%; p < 0.001) with higher body mass index (25.7 ± 4.0 vs. 31.3 ± 5.3 kg/m²; p < 0.001) and higher blood pressure (135 ± 18 vs. 140 ± 17 mmHg; p = 0.012) compared to individuals without OSA or snoring. Regression analysis showed a significant effect for OSA in left ventricular end-diastolic index (LVEDVI) (β = −4.9 ± 2.4 mL/m²; p = 0.040) and right ventricular end-diastolic index (RVEDVI) (β = −6.2 ± 2.6 mL/m²; p = 0.016) in females and for right ventricular ejection fraction (RVEF) (β = 1.7 ± 0.8%; p = 0.031) in males. A significant effect was discovered in snoring females for left ventricular mass index (LVMI) (β = 3.5 ± 0.9 g/m²; p < 0.001) and in males for left ventricular ejection fraction (LVEF) (β = 1.0 ± 0.3%; p = 0.001) and RVEF (β = 1.2 ± 0.3%; p < 0.001). Conclusion: Our study suggests that OSA is highly underdiagnosed and that it is an evolving process with gender specific progression. Females with OSA show significantly lower ventricular volumes while males with snoring show increased ejection fractions which may be an early sign of hypertrophy. Separate prospective studies are needed to further explore the direction of causality.

Hypoglossal nerve stimulation impact on a patient with obstructive sleep apnea and heart failure

A 75-year-old man with body mass index of 30.5 kg/m² and severe obstructive sleep apnea (OSA) with an apnea-hypopnea index (AHI) of 72 events/h was referred for upper airway stimulation (UAS) therapy. Past medical history was significant for cardiovascular disease including congestive heart failure due to ischemic cardiomyopathy with impaired left ventricular function and ejection fraction of 35%. Following evaluation of clinical and polysomnographic data, he was an appropriate candidate for UAS and underwent uncomplicated implantation. Three months postoperatively, polysomnography showed a titrated AHI of 0 events/h. Follow-up cardiac evaluation revealed ejection fraction increase to 47% since implantation. No interval change in medical management or body mass index had occurred. Given the high prevalence of OSA in patients with cardiovascular disease, UAS may become an important adjunct in the comprehensive multidisciplinary treatment of heart failure in patients with OSA. Further clinical studies are required to investigate the impact of UAS on treatment and prognosis of heart disease.

Obstructive sleep apnea during acute coronary syndrome is related to myocardial necrosis and wall stress

BACKGROUND

The relative contribution of pathophysiological mechanisms in acute coronary syndrome (ACS) towards obstructive sleep apnea (OSA) is not well-studied. We examined the correlation between severity of OSA and inflammation, myocardial necrosis, wall stress, and fibrosis.

METHODS

A total of 89 patients admitted with ACS underwent a sleep study during index admission. Plasma levels of high-sensitivity C-reactive protein (hs-CRP), troponin I, N-terminal pro-brain natriuretic peptide (NT-proBNP), and suppression of tumorigenicity 2 (ST2) were prospectively analyzed. Two patients diagnosed with central sleep apnea were excluded.

RESULTS

The recruited patients were divided into no (AHI <5 events/hour, 9.2%), mild (5-<15, 27.6%), moderate (15-<30, 21.8%), and severe (≥30, 41.4%) OSA. Compared to the no, mild and moderate OSA groups, the severe OSA group had a higher body mass index (p = 0.005). They were also more likely to present with ST-segment elevation ACS (versus non-ST-segment elevation ACS) (p = 0.041), have undergone previous coronary artery bypass grafting (p = 0.013), demonstrate complete coronary occlusion during baseline coronary angiography (p = 0.049), and have a larger left atrial diameter measured on echocardiography (p = 0.029). Likewise, the severe OSA group had higher plasma levels of hs-CRP (p = 0.004), troponin I (p = 0.017), and NT-proBNP (p = 0.004), but not ST2 (p = 0.10). After adjustment for the effects of confounding variables, OSA was independently associated with troponin I (ie, myocardial necrosis; p = 0.001) and NT-proBNP (ie, myocardial wall stress; p = 0.008).

CONCLUSION

Severe OSA during the acute phase of ACS was associated with extensive myocardial necrosis and high myocardial wall stress, but not with inflammation and myocardial fibrosis.

Association Between Obstructive Sleep Apnea-Hypopnea Syndrome and Outcomes in Patients With Myocardial Infarction in the Absence of Obstructive Coronary Artery Disease

Background and Aims: Myocardial infarction in the absence of obstructive coronary artery disease (MINOCA) occurs in 5-10% of all patients with acute myocardial infarction. Obstructive sleep apnea-hypopnea syndrome (OSAHS) is linked to increased cardiovascular morbidity and mortality, but the relationship of OSAHS and outcomes in patients with MINOCA remains unknown. We aimed to evaluate the association between OSAHS and clinical outcomes in patients with MINOCA. Methods: Between January 2015 and December 2016, we carried out a consecutive cohort study of 583 patients with MINOCA and followed them up for 3 years. An apnea-hypopnea index of ≥ 15 events per hour recorded by polysomnography was defined as the diagnostic criterion for OSAHS. The primary end point was all-cause mortality, and the second end point was major adverse cardiovascular or cerebrovascular events (MACCE), a composite of cardiac death, non-fatal myocardial infarction, heart failure, cardiovascular-related rehospitalization, and stroke. Results: All-cause mortality happened in 69 patients and MACCE occurred in 113 patients during the 3-year follow-up. Kaplan-Meier survival curves indicated the significant relationship of OSAHS with all-cause mortality (log-rank P = 0.012) and MACCE (log-rank P = 0.002). Multivariate Cox regression analysis indicated OSAHS as an independent predictor of all-cause mortality and MACCE [adjusted hazard ratio: 1.706; 95% confidence interval (CI): 1.286-2.423; P = 0.008; and adjusted hazard ratio: 1.733; 95% CI: 1.201-2.389; P < 0.001; respectively], independent of age, sex, cardiovascular risk factors and discharge medications. Conclusions: OSAHS is independently associated with increased risk of all-cause mortality and MACCE in patients with MINOCA. Intervention and treatment should be considered to alleviate OSAHS-associated risk.

Non-traditional risk factors and the risk of myocardial infarction in the young in the US population-based cohort

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Young patients with myocardial infarction (MI) have both traditional risk factors and non-traditional risk factors.

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HTN, smoking, obesity, HLD and a family history of CAD were risks of MI in the young.

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HIV, SLE, and OSA were all associated with an elevated risk of MI, independent of traditional atherosclerotic risk factors.

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Close attention should be paid to emerging risk factors such as SLE, HIV and OSA.

Although most prevalent in elderly, myocardial infarction (MI) also affects younger adults. We sought to investigate baseline characteristics in young patients (<55 years) with MI using the National Inpatient Sample (NIS) database between 2004 and 2015. Multivariable logistic regression models were used to assess factors associated with acute myocardial infarction (AMI) in young patients. After multivariable analyses adjusted for age, sex, race, family history of atherosclerosis, body mass index (BMI), diabetes, hypertension, hyperlipidemia, chronic kidney disease, and current cigarette smoking; novel risk factors such as human immunodeficiency virus (HIV), systemic lupus erythematosus (SLE), and obstructive sleep apnea (OSA) were associated with a higher risk of developing an AMI in the young (adjusted OR for HIV 4.06; 95 CI 3.48–4.71, p < 0.001), (adjusted OR for SLE 2.12; 95 CI 1.89–2.39, p 0.04), and (adjusted OR for OSA 1.16; 95 CI 1.12–1.20, p < 0.001), respectively. Rheumatoid arthritis was associated with a lower risk of AMI (adjusted OR 0.83; 95 CI 0.76–0.89, p < 0.001). After multivariable analyses, cigarette smoking (adjusted OR 1.98; 95 CI 1.95–2.02, p < 0.001), obesity (adjusted OR 1.37; 95 CI 1.33–1.41, p = 0.003), hyperlipidemia (adjusted OR 1.07; 95 CI 1.04–1.08, p < 0.001) and a family history of CAD (adjusted OR 1.35; 95 CI 1.3–1.4, p < 0.001) were also associated with a higher risk of developing an AMI in the young. In conclusion, young patients with AMI have both traditional risk factors and non-traditional risk factors. In addition to traditional risk factors, close attention should be paid to emerging risk factors such as SLE, HIV and OSA.

Obstructive sleep apnoea but not central sleep apnoea is associated with left ventricular remodelling after acute myocardial infarction

Obejctive

Obstructive sleep apnoea (OSA) increases left ventricular transmural pressure more than central sleep apnoea (CSA) owing to negative intrathoracic pressure swings. We tested the hypothesis that the severity of OSA, and not CSA, is therefore associated with spheric cardiac remodelling after acute myocardial infarction.

Methods

This sub-analysis of a prospective observational study included 24 patients with acute myocardial infarction who underwent primary percutaneous coronary intervention. Spheric remodelling, calculated according to the sphericity index, was assessed by cardiac magnetic resonance imaging at baseline and 12 weeks after acute myocardial infarction. OSA and CSA [apnoea-hypopnoea index (AHI) ≥ 5/hour] were diagnosed by polysomnography.

Results

Within 12 weeks after acute myocardial infarction, patients with OSA exhibited a significant increase in systolic sphericity index compared to patients without sleep-disordered breathing (no SDB) and patients with CSA (OSA vs. CSA vs. no SDB: 0.05 ± 0.04 vs. 0.01 ± 0.04 vs. − 0.03 ± 0.03, p = 0.002). In contrast to CSA, the severity of OSA was associated with an increase in systolic sphericity index after accounting for TIMI-flow before percutaneous coronary intervention, infarct size, pain-to-balloon-time and systolic blood pressure [OSA: B (95% CI) 0.443 (0.021; 0.816), p = 0.040; CSA: 0.193 (− 0.134; 0.300), p = 0.385].

Conclusion

In contrast to CSA and no SDB, OSA is associated with spheric cardiac remodelling within the first 12 weeks after acute myocardial infarction. Data suggest that OSA-related negative intrathoracic pressure swings may contribute to this remodelling after acute myocardial infaction.

Graphic abstract

Electronic supplementary material

The online version of this article (10.1007/s00392-020-01684-z) contains supplementary material, which is available to authorized users.

Integrating the STOP-BANG Score and Clinical Data to Predict Cardiovascular Events After Infarction: A Machine Learning Study

BACKGROUND

OSA conveys worse clinical outcomes in patients with coronary artery disease. The STOP-BANG score is a simple tool that evaluates the risk of OSA and can be added to the large number of clinical variables and scores that are obtained during the management of patients with myocardial infarction (MI). Currently, machine learning (ML) is able to select and integrate numerous variables to optimize prediction tasks.

RESEARCH QUESTION

Can the integration of STOP-BANG score with clinical data and scores through ML better identify patients who experienced an in-hospital cardiovascular event after acute MI?

STUDY DESIGN AND METHODS

This is a prospective observational cohort study of 124 patients with acute MI of whom the STOP-BANG score classified 34 as low (27.4%), 30 as intermediate (24.2%), and 60 as high (48.4%) OSA-risk patients who were followed during hospitalization. ML implemented feature selection and integration across 47 variables (including STOP-BANG score, Killip class, GRACE score, and left ventricular ejection fraction) to identify those patients who experienced an in-hospital cardiovascular event (ie, death, ventricular arrhythmias, atrial fibrillation, recurrent angina, reinfarction, stroke, worsening heart failure, or cardiogenic shock) after definitive MI treatment. Receiver operating characteristic curves were used to compare ML performance against STOP-BANG score, Killip class, GRACE score, and left ventricular ejection fraction, independently.

RESULTS

There were an increasing proportion of cardiovascular events across the low, intermediate, and high OSA risk groups (P = .005). ML selected 7 accessible variables (ie, Killip class, leukocytes, GRACE score, c reactive protein, oxygen saturation, STOP-BANG score, and N-terminal prohormone of B-type natriuretic peptide); their integration outperformed all comparators (area under the curve, 0.83 [95% CI, 0.74-0.90]; P < .01).

INTERPRETATION

The integration of the STOP-BANG score into clinical evaluation (considering Killip class, GRACE score, and simple laboratory values) of subjects who were admitted for an acute MI because of ML can significantly optimize the identification of patients who will experience an in-hospital cardiovascular event.

Prevalence of Undiagnosed Obstructive Sleep Apnea Among Patients Hospitalized for Cardiovascular Disease and Associated In-Hospital Outcomes: A Scoping Review

BACKGROUND

Obstructive sleep apnea (OSA) is associated with long-term cardiovascular morbidity and is highly prevalent in patients with cardiovascular disease (CVD). The objectives of this scoping review were to determine the prevalence of OSA inpatients hospitalized for CVD and to map the range of in-hospital outcomes associated with OSA.

METHODS

We searched MEDLINE(R), Embase, and Cochrane Databases for articles published from 1946-2018. We included studies involving non-surgical adults with OSA or at high risk of OSA who were hospitalized for CVD. The outcomes were considered as in-hospital if they were collected from admission up to 30 days post-discharge from hospital.

RESULTS

After the screening of 4642 articles, 26 studies were included for qualitative synthesis. Eligible studies included patients presenting with acute coronary syndromes (n = 19), congestive heart failure (n = 6), or any cardiovascular disease (n = 1). The pooled prevalence of OSA in cardiac inpatients was 48% (95% CI: 42-53). The in-hospital outcomes reported were mortality (n = 4), length of stay (n = 8), left ventricular ejection fraction (n = 8), peak troponin (n = 7), peak B-type natriuretic peptide (n = 4), and composite cardiovascular complications (n = 2).

CONCLUSIONS

OSA is highly prevalent in the cardiac inpatient population. The outcomes reported included mortality, cardiac function, cardiac biomarkers, and resource utilization. There are significant knowledge gaps regarding the effect of treatment and OSA severity on these outcomes. The findings from this review serve to inform further areas of research on the management of OSA among patients with CVD.

Sleep Apnea and Heart

Scientific investigations in the past few decades have supported the important role of sleep in various domains of health. Sleep apnea is a highly prevalent yet underdiagnosed sleep disorder representing a valid cardiovascular risk factor, particularly for hypertension. While several studies have demonstrated the benefits of sleep apnea treatment on subclinical cardiovascular measures, there is a paucity of studies proving reduction of cardiovascular events and mortality. Sufficient and high-quality sleep is also important in the maintenance of cardiovascular health. Future investigations should focus on improving identification of patients at greatest risk of adverse cardiovascular s sequalae of sleep apnea and testing the therapeutic benefit of sleep apnea treatment in this vulnerable group.

Central Sleep Apnoea and Arrhythmogenesis After Myocardial Infarction-The CESAAR Study

The prevalence of sleep disordered breathing (SDB) after acute myocardial infarction (AMI) is high. However, little is known about predominant SDB type and the impact of SDB severity on arrhythmogenesis. We conducted a prospective single-center observational study and performed an unattended sleep study and Holter monitoring within 10 days after AMI, and an unattended sleep study 11.3 months after AMI. All patients were included from the Department of Cardiology at the University Hospital Schleswig-Holstein, Lübeck, Germany. A total of 202 subjects with AMI (73.8% with ST-elevation; 59.8 years; 73.8% male) were included. The mean BMI was 27.8 kg/m² and the mean neck/waist circumference was 41.7/103.3 cm. The mean left ventricular ejection fraction was 56.6%. The SDB prevalence defined as apnoea-hypopnea-index (AHI) ≥ 5/h was 66.7% with 44.9% having central (CSA), and 21.8% obstructive sleep apnoea (OSA). The mean AHI was 13.8 1/h. In 10.2% nsVT was detected in the Holter monitoring. AI >23/h was independently associated with higher risk of nsVT in the subacute AMI period. SDB is highly prevalent and CSA a predominant type of SDB in the subacute phase after uncomplicated AMI treated with modern revascularization procedures and evidence-based pharmacological therapy. Severe SDB is independently associated with higher risk for nsVT in the subacute AMI period and its course should be monitored as it can potentially have a negative impact on relevant outcomes of AMI patients. Further prospective studies are needed to assess long-term follow up of SDB after AMI and its impact on mortality and morbidity.

Real-world STOPBANG: how useful is STOPBANG for sleep clinics?

PURPOSE

The STOPBANG questionnaire has been widely used for screening obstructive sleep apnea (OSA) due to its time friendly, economic advantages over overnight polysomnography (PSG). The aim of this study was to analyze the usefulness of the items constituting the utility of STOPBANG in a sleep clinic and to establish the best assembly for OSA-screening methods in the Korean population.

METHODS

We retrospectively analyzed all patients who completed PSG as well as STOPBANG at a sleep center in a tertiary hospital from January 2016 to December 2017. The sensitivity and specificity of STOPBANG and its smaller counterparts (i.e., SOPBAG) were compared.

RESULTS

A total of 541 subjects completed PSG and STOPBANG. Two hundred thirty-five patients were diagnosed with OSA (OSA+) and were compared to those who were not (OSA-). The respective scores of STOPBANG in OSA+ versus OSA- were 4.29 ± 1.46 and 2.53 ± 1.48 (p < 0.001). There were significant differences in all factors except tiredness and age (SOPBNG). STOPBANG showed sensitivity of 89.1% and specificity of 57.4%. The AUC was 0.809. Excluding tiredness as well as neck circumference (SOPBAG), the AUC was 0.811. The sensitivity and specificity were 71.8% and 77.9%, respectively. The AUC of SOPBAG was neither superior nor inferior to that of STOPBANG.

CONCLUSION

The screening value of STOPBANG for OSA did not perform as expected when compared to PSG for accuracy in Koreans. STOPBANG can be simplified to SOPBAG while maintaining comparable screening performance. It may be practical to consider performing PSGs without the use of the STOPBANG in Korea.

Sleep disturbances are common in patients with autoimmune encephalitis

OBJECTIVES

Autoimmune encephalitis (AE) is increasingly recognized as an important cause of subacute cognitive decline, seizures, and encephalopathy, with an ever-broadening clinical phenotype. Sleep disturbances are reported in AE patients, including rapid eye movement sleep behavior disorder, hypersomnia, fragmented sleep, and sleep-disordered breathing; however, the prevalence of sleep disturbances and contributions to outcomes in AE patients remain unknown. There is a need to determine the prevalence of sleep disturbances in AE patients, and to clarify the relationship between specific autoantibodies and disruptions in sleep.

METHODS

Clinical history, results of serum and cerebrospinal fluid testing, electroencephalography, and neuroimaging were reviewed from 26 AE patients diagnosed and managed at our tertiary care hospital. Polysomnography was performed in patients with clinical indications, yielding data from 12 patients.

RESULTS

The median age of AE patients was 53 years (range 18-83). Autoantibodies against intracellular antigens (including Ma and Hu autoantibodies) were identified in 6/26 (23%) patients, while autoantibodies against cell-surface neuronal antigens (including NMDAR and LGI1) were identified in 20/26 (77%) patients. New sleep complaints were reported by 19/26 (73%) AE patients, including gasping or snoring (9/19, 47%), dream enactment behavior (6/19, 32%), insomnia (5/19, 29%), hypersomnia (4/19, 21%), other parasomnias (4/19, 21%), and dream-wake confusional states (2/19, 11%). Dream enactment behaviors were particularly common in AE associated with LGI1 autoantibodies, reported in 4/7 (57%) patients. Polysomnography showed reduced total sleep time, stage 3 and rapid eye movement sleep, and prominent sleep fragmentation.

CONCLUSION

Sleep disturbances are common in AE, warranting active surveillance in affected patients. Improved identification and treatment of sleep disorders may reduce morbidity associated with AE and improve long-term outcomes.

Sleep Apnea Evolution and Left Ventricular Recovery After Percutaneous Coronary Intervention for Myocardial Infarction

STUDY OBJECTIVES

Sleep apnea is often newly diagnosed in patients presenting with ST-segment elevation myocardial infarction (STEMI). We assessed longitudinal changes in apnea-hypopnea index (AHI) and sleep apnea phenotype after STEMI and determined its association with changes in the left ventricular ejection fraction (LVEF).

METHODS

A total of 101 eligible patients with STEMI underwent consecutive sleep studies and echocardiographic studies within 5 days of admission and at 6-month follow-up. Sleep apnea (AHI ≥ 15 events/h) was further divided into obstructive sleep apnea (OSA) or central sleep apnea (CSA).

RESULTS

Both AHI (mean difference -6.4 events/h, 95% confidence interval [CI] -9.6 to 3.3, P < .001) and LVEF (mean difference 2.6%, 95% CI 1.3 to 4.0, P < .001) improved from baseline to 6 months. The improvement in AHI was associated with an increase in LVEF (β = -.47, 95% CI -.86 to -.07, P = .023) and a decrease in left ventricular end-systolic volume (LVESV) (β = .25, 95% CI .07 to .43, P = .007). Of the patients with OSA at baseline (46%), resolution of OSA was seen in 48% at 6 months. Of those with CSA at baseline (12%), conversion to OSA was seen in 83%. In contrast, among those with no sleep apnea (42%) at baseline, the diagnosis remained the same in 93% at 6 months.

CONCLUSIONS

Concurrent changes in AHI, LVEF, and LVESV were seen after STEMI. Sleep studies performed on admission are reliable in excluding sleep apnea. However, patients with OSA or CSA on admission warrant re-evaluation due to evolution of the sleep apnea phenotype.

Impact of Obstructive Sleep Apnea on Platelet Function Profiles in Patients With Acute Coronary Syndrome Taking Dual Antiplatelet Therapy

Background Obstructive sleep apnea ( OSA ) is a novel risk factor for acute coronary syndrome ( ACS ). Several studies have shown OSA to be associated with induced platelet reactivity. However, whether OSA have effects on platelet function profiles in ACS patients taking dual antiplatelet therapy remains unexplored. Methods and Results This was a cross-sectional observational study, in which ACS patients taking maintenance aspirin and clopidogrel therapy were included. OSA was defined as an apnea-hypopnea index ≥15 events/hour. The inhibitory rate of arachidonic acid or adenosine diphosphate pathway were assessed with thrombelastography and defined patients with high residual on-treatment platelet reactivity. Platelet indices were obtained from routine analysis of blood samples using an automated blood cell counter. A total of 127 ACS patients taking dual antiplatelet therapy were analyzed. Platelet volume indices, including mean platelet volume and platelet large cell ratio, were significantly increased in patients with OSA . Patients with OSA (n=68) had significantly lower inhibitory rate of adenosine diphosphate receptor pathway ( P=0.028) compared with those without (n=59). After adjustment for potential confounders, patients with OSA were more likely to have high residual on-treatment platelet reactivity after clopidogrel therapy (adjusted odds ratio: 3.25, 95% confidence interval: 1.19-8.87, P=0.021). Conclusions In ACS patients taking dual antiplatelet therapy, OSA is associated with an increased level of platelet volume indices, reduced clopidogrel-induced antiplatelet effects and a greater prevalence of high residual on-treatment platelet reactivity.

Obstructive sleep apnoea: from respiratory events to coronary microvascular dysfunction

Obstructive sleep apnoea (OSA) is an emerging and independent risk factor for cardiovascular diseases; coronary artery disease (CAD) is higher in OSA patients, even in the absence of other traditional cardiovascular risk factors. There is little evidence to show abnormalities in coronary blood flow (CBF) and disorders in coronary vascular resistance (CVR), occurring during the obstructive respiratory event, suggesting coronary microvascular dysfunction (CMD) as a potential mechanism of ischaemic heart disease (IHD) OSA-as a related consequence.

High Risk Characteristics for Recurrent Cardiovascular Events among Patients with Obstructive Sleep Apnoea in the SAVE Study

BACKGROUND

Obstructive sleep apnoea (OSA) is a common comorbidity in patients with cardiovascular (CV) disease. We aimed to identify specific OSA clinical phenotypes relating to risks of serious CV events and response to continuous positive airway pressure (CPAP) treatment.

METHODS

Post-hoc analyses of the Sleep Apnea Cardiovascular Endpoints (SAVE) study in participants with moderate-to-severe OSA and coronary artery disease (CAD) and/or cerebrovascular disease (CeVD) randomised to CPAP plus usual care or usual care alone. Latent class analysis (LCA) was used to identify OSA clinical phenotypes among 2649 (out of 2687 total) patients with complete data on 19 patient-centered variables, supported by Bayesian information criteria and clinical interpretability. Cox regression models were used to evaluate risks of composite cardiac and stroke outcome events in phenotype groups. Preferential response to CPAP treatment was evaluated using interaction terms as well as the Chi-square test.

FINDINGS

LCA identified four OSA clinical phenotypes: CAD alone and with diabetes mellitus (CAD + DM), and CeVD alone and with DM (CeVD + DM), in 39%, 15%, 37% and 9% of participants, respectively. The rates of composite CV events were the highest in CAD + DM phenotype (HR 2.08, 95% CI 1.57-2.76) and for stroke were highest in CeVD + DM phenotype (HR 6.84, 95% CI 3.77-12.42). Adherence to CPAP treatment (nil or < 4 h vs ≥ 4 h in the first two years of the study) was shown to influence the risk of composite CV outcome in the phenotypes (P-interaction = 0.04); CPAP adherent patients of the CeVD + DM phenotype had the lowest risk of CV outcome (P = 0.02).

INTERPRETATION

High risk clinical phenotypes were identified in relation to CV events and response to CPAP treatment, which may allow improved targeting of therapies in OSA patients.

FUNDING

The National Health and Medical Research Council (NHMRC) of Australia, Fisher & Paykel Healthcare, and ResMed.

Syndrome 'Z': A Predictor of Angiographic Severity of Coronary Artery Disease in Patients of Acute Coronary Syndrome

BACKGROUND

Owing to the growing evidence that the pathophysiology of obstructive sleep apnoea (OSA) and metabolic syndrome (MS) overlap considerably and both adversely impact cardiovascular health, we hypothesised that the presence of OSA with MS additively and adversely affect the severity of coronary artery disease (CAD). Exploration and understanding of this may have direct implications for the development of targeted, preventive strategies for CAD. Thus, this prospective study was aimed to determine the prevalence of 'Syndrome Z' in patients of MS who present with an acute coronary event and to correlate it with the angiographic severity of CAD in these patients.

METHODS

The present study was a single centre, cross sectional study conducted in a university teaching hospital. In a span of 6 months, 922 patients with acute coronary syndromes (ACS) were screened for the study. Among these, 861 patients had no evidence of MS. The remaining 61 patients who were diagnosed to have MS were then subjected to an overnight sleep study. Only 58 had good sleep data so were included for further analysis. Angiographic parameters in terms of number of vessels involved and culprit lesions were noted and correlated with presence and absence of OSA and also with its severity based on the Apnoea/Hypopnoea Index (AHI).

RESULTS

The prevalence of OSA positivity in patients with MS who presented with ACS was 34.5% (n=20). Most of the patients in the OSA negative group (78.9%, n=30) had disease limited to only one vessel while in the OSA positive group only a minority (15%, n=3) of patients had their disease limited to a single vessel (p=0.001). The number of lesions in the culprit vessel was also significantly less in the OSA negative group compared to the OSA positive group. While in the OSA negative group 68.4% (n=26) patients had a solitary lesion, followed by two and three lesions in 15.8% (n=6) of the patients each, multiple lesions were more common in OSA positive patients, involving 80% of cases (45.0%, n=9 with two lesions; 35.0%, n=7 with three lesions; only 20%, n=4 had a solitary lesion).

CONCLUSIONS

Prevalence of 'Syndrome Z' is high in patients having MS presenting with ACS and it correlates with the angiographic severity of CAD.

Watch-PAT versus level III device in diagnosing sleep disordered breathing in first myocardial infarction

BACKGROUND

Watch-PAT 200, a novel portable sleep device worn on the wrist, has been validated against polysomnography. Although sleep disordered breathing (SDB) screening is recommended in patients with cardiovascular disease, no study has reported a comparison of results from Watch-PAT 200 and level III portable devices.

METHODS

Patients (n = 140) admitted with a first ST-segment elevation myocardial infarction (STEMI) participated in a hospital-based sleep study using the Watch-PAT 200 and a level III portable device (Embletta Gold) simultaneously within five days of admission. SDB was defined as an apnea-hypopnea index (AHI) of >15 events/h.

RESULTS

The left ventricular ejection fraction was normal (≥50%), impaired (30%-49%) and poor (<30%) in 66 (47.1%), 71 (50.7%), and three (2.2%) patients, respectively. Among 116 patients with a successful paired sleep study, the prevalence of SDB was 53.5% (Watch-PAT 200) and 51.7% (Embletta Gold). The agreement of AHI measured by the two devices was moderately good, with an intra-class correlation value of 0.72 (95% confidence interval, 0.62-0.80; P < .01). Agreement between the two devices in diagnosing at least mild (AHI ≥5), moderate-to-severe (AHI ≥15) and severe (AHI ≥30) SDB was 78% (kappa 0.47; P < .01), 77% (kappa 0.55; P < .01) and 80% (kappa 0.49; P < .01), respectively. At a 15-month follow-up, SDB status based on the two devices was associated with the occurrence of adverse cardiovascular events in 48.3% and 44.8%, respectively (P = .56).

CONCLUSION

We found a high prevalence of SDB in patients presenting with a first STEMI. Agreement between two portable sleep devices was moderately good.

Modified Mallampati Score Improves Specificity of STOP-BANG Questionnaire for Obstructive Sleep Apnea

BACKGROUND

An accurate, clinical screening tool for obstructive sleep apnea (OSA) that identifies patients for further diagnostic testing would assist in the diagnosis of this comorbidity. One example, the STOP-BANG questionnaire (SBQ), has been validated as a screening tool with high sensitivity. However, its specificity may result in a high false-positive rate. The aim of this study to determine if addition of the Modified Mallampati score to the SBQ improves its specificity.

METHODS

The authors studied 162 patients referred to the Sleep Disorders Clinic at Yedikule Chest Disease Education and Research Hospital. All patients were prospectively screened for risk of OSA using the SBQ, their oral anatomy was assessed by Modified Mallampati scoring, and sleep quality characterized by polysomnography. Polysomnography results were reviewed when available and the predictive performance of the SBQ and the modified SBQ scoring models were compared.

RESULTS

In the authors' study an SBQ score ≥3 yielded sensitivities of 0.85, 0.86, and 0.91 for Apnea-Hypopnea Index (AHI) ≥5/h, AHI ≥15/h, and AHI ≥30/h, respectively, and specificities of 0.09, 0.10, and 0.18. The modified SBQ with a cutoff of ≥4 (>3) points for AHI levels of >5, >15, and >30 yielded respective sensitivities of 0.84, 0.86, and 0.91 and specificities of 0.25, 0.26, and 0.27.

CONCLUSIONS

The author's results from indicated the modified SBQ with a cutoff of >3 points in this study was more specific than the standard SBQ but no less sensitive, and may be used in identifying OSA patients for further diagnostic evaluation or avoiding unnecessary testing.

Obstructive Sleep Apnea in a rural population in South India: Feasibility of health care workers to administer level III sleep study

Objectives:

To estimate the occurrence of obstructive sleep apnea (OSA) and its risk factors in a rural Indian population using screening questionnaire and Level III sleep study. To determine the feasibility to train community health workers to administer Level III sleep study in the high-risk population.

Materials and Methods:

The study was conducted from seven villages with adult population of 2247, in Mugalur, near Bengaluru, from January to April 2014. Berlin questionnaire was used to screen 321 participants chosen by stratified random sampling. A total of 26 out of 321 patients underwent Level III sleep study at home, administered by the health workers, who were trained in three sessions to hook up the machine. Data were verified by a certified sleep physician.

Results:

The mean age was 39.43 ± 15.6 years with the M:F ratio of 0.98:1. Prevalence of risk of OSA by Berlin questionnaire was 8.72% (95% confidence interval [CI] 5.63, 11.81) in the total population, 7.4% in males and 11.7% in females. Older age (odds ratio [OR] 3.97; CI 1.63, 9.6), hypertension (OR 11; CI 4.3, 28.2), obesity (OR 2.35; CI 1, 5.5), and higher Mallampati score (OR 3.78; CI 1.7, 8.4) were significantly associated with high risk of OSA (P = 0.0001–0.04). Twenty-six patients underwent Level III sleep study and OSA was diagnosed in 12 patients. The mean apnea–hypopnea index (AHI) of this group was 9.7/h. The prevalence of OSA by AHI criteria was 3.74%.

Conclusions:

OSA is underdiagnosed in rural populations, although risk factors are present. Training community health workers to administer Level III sleep study is a feasible and cost-effective strategy.

High risk for obstructive sleep apnea in patients with acute myocardial infarction

OBJECTIVES

to stratify the risk for obstructive sleep apnea in patients with acute myocardial infarction, treated at a public, tertiary, teaching hospital of the state of São Paulo, Brazil, and to identify related sociodemographic and clinical factors.

METHOD

cross-sectional analytical study with 113 patients (mean age 59.57 years, 70.8% male). A specific questionnaire was used for the sociodemographic and clinical characterization and the Berlin Questionnaire for the stratification of the risk of obstructive sleep apnea syndrome.

RESULTS

the prevalence of high risk was 60.2% and the outcome of clinical worsening during hospitalization was more frequent among these patients. The factors related to high risk were body mass index over 30 kg/m2, arterial hypertension and waist circumference indicative of cardiovascular risk, while older age (60 years and over) constituted a protective factor.

CONCLUSION

considering the high prevalence of obstructive sleep apnea and its relation to clinical worsening, it is suggested that nurses should monitor, in their clinical practice, people at high risk for this syndrome, guiding control measures of modifiable factors and aiming to prevent the associated complications, including worsening of cardiovascular diseases.

Recognized Obstructive Sleep Apnea is Associated With Improved In-Hospital Outcomes After ST Elevation Myocardial Infarction

BACKGROUND

Obstructive sleep apnea (OSA) is an independent risk factor for many cardiovascular conditions such as coronary artery disease, myocardial infarction, systemic hypertension, pulmonary hypertension, and stroke. However, the association of OSA with outcomes in patients hospitalized for ST-elevation myocardial infarction remains controversial.

METHODS AND RESULTS

We used the nation-wide inpatient sample between 2003 and 2011 to identify patients with a primary discharge diagnosis of ST-elevation myocardial infarction and then used the International Classification of Diseases, Clinical Modification code 327.23 to identify a group of patients with OSA. The primary outcome of interest was in-hospital mortality, and secondary outcomes were in-hospital cardiac arrest, length of stay and hospital charges. Our cohort included 1 850 625 patients with ST-elevation myocardial infarction, of which 1.3% (24 623) had documented OSA. OSA patients were younger and more likely to be male, smokers, and have chronic pulmonary disease, depression, hypertension, known history of coronary artery disease, dyslipidemia, obesity, and renal failure (P<0.001 for all). Patients with OSA had significantly decreased in-hospital mortality (adjusted odds ratio, 0.78 [95% CI, 0.73-0.84]), longer hospital stay (5.00±4.68 versus 4.85±5.96 days), and incurred greater hospital charges ($79 460.12±70 621.91 versus $62 889.91±69 124.15). There was no difference in incidence of in-hospital cardiac arrest (adjusted odds ratio, 0.93 [95% CI, 0.84-1.03]) between these 2 groups.

CONCLUSION

ST-elevation myocardial infarction patients with recognized OSA had significantly decreased mortality compared with patients without OSA. Although patients with OSA had longer hospital stays and incurred greater hospital charges, there was no difference in incidence of in-hospital cardiac arrest.

Cardiac Troponin Values in Patients With Acute Coronary Syndrome and Sleep Apnea: A Pilot Study

BACKGROUND

An analysis of cardiac injury markers in patients with OSA who sustain an episode of acute coronary syndrome (ACS) may contribute to a better understanding of the interactions and impact of OSA in subjects with ACS. We compared peak cardiac troponin I (cTnI) levels in patients with OSA and patients without OSA who were admitted for ACS.

METHODS

Blood samples were collected every 6 hours from the time of admission until two consecutive assays showed a downward trend in the cTnI assay. The highest value obtained defined the peak cTnI value, which provides an estimate of infarct size.

RESULTS

We included 89 patients with OSA and 38 patients without OSA with an apnea-hypopnea index of a median of 32 (interquartile range [IQR], 20.8-46.6/h and 4.8 [IQR, 1.6-9.6]/h, respectively. The peak cTnI value was significantly higher in patients without OSA than in patients with OSA (median, 10.7 ng/mL [IQR, 1.78-40.1 ng/mL] vs 3.79 ng/mL [IQR, 0.37-24.3 ng/mL]; P = .04). The multivariable linear regression analysis of the relationship between peak cTnI value and patient group, age, sex, and type of ACS showed that the presence or absence of OSA significantly contributed to the peak cTnI level, which was 54% lower in patients with OSA than in those without OSA.

CONCLUSIONS

The results of this study suggest that OSA has a protective effect in the context of myocardial infarction and that patients with OSA may experience less severe myocardial injury. The possible role of OSA in cardioprotection should be explored in future studies.

Prevalence of obstructive sleep apnoea in acute coronary syndrome: Routine screening in intensive coronary care units

INTRODUCTION

Increased evidence has shown that, despite the maximum care afforded to patients admitted with acute coronary syndromes (ACS), a residual risk of mortality remains, in which obstructive sleep apnoea (OSA) appears to be a largely undiagnosed factor, particularly in the intensive cardiac care unit (ICCU). The purpose of this study is to determine whether the systematic screening for sleep-disordered breathing (SDB) is feasible and may be recommended. The aims of our study are to determine: (1) The estimated prevalence of OSA in patients admitted to the ICCU for ACS determined by a validated, user-friendly portable screening device; (2) The feasibility of the screening in this context; (3) To assess any negative impact of OSA on the severity of ACS.

PATIENTS AND METHODS

This is an observational study of 101 patients admitted to the ICCU for ACS showing no clinical evidence of heart failure (HF). In the 24-72hours following admission, they underwent an overnight sleep study using a 3-channel portable screening device with automatic analysis.

RESULTS

Sixty-two out of the 101 patients proved positive to the screening test, and its feasibility was acceptable. OSA patients tended to have greater peak levels of hs-cTnT (3685±3576ng/L versus 2830±3333ng/L, P=0.08) than the non-OSA group. Compared with the non-OSA group, OSA patients presented more severe ACS, with a greater average GRACE score at admission of 112.2±26.3 (versus 98.4±19.2, P<0.001). In the OSA group, we found a statistically significant inverse correlation between the apnoea-hypopnea index (AHI) and the left ventricular ejection fraction (LVEF) in the linear regression analysis (r=-0.26; P=0.037).

CONCLUSIONS

A systematic screening of patients in the ICCU is acceptable. OSA is frequently found in the acute phase of ischaemic heart disease and its presence is associated with more severe ACS and a poorer left ventricle systolic function.

Recognition and treatment of sleep-disordered breathing: an important component of chronic disease management

Sleep-disordered breathing (SDB) is a highly prevalent condition, and is associated with many debilitating chronic diseases. The role of untreated obstructive sleep apnea (OSA) in arterial hypertension has been recognized in international guidelines. Treatment with continuous positive airway pressure (CPAP) is associated with clinically-relevant reductions in blood pressure. In heart failure (HF), SDB is associated with worse prognosis and increased mortality. Major HF guidelines recommend that patients should be treated for sleep apnea to improve their HF status. Severe OSA increases the risk of arrhythmias, including atrial fibrillation, influences risk management in stroke, and is highly prevalent in patients with type 2 diabetes. Effective treatment with CPAP improves the success of antiarrhythmic interventions, improves outcomes in stroke and reduces hyperglycemia in diabetes. Patients with coronary artery disease also have a high prevalence of SDB, which is independently associated with worse outcomes. The role of CPAP for secondary cardiovascular prevention remains to be determined. Data from large, well-conducted clinical trials have shown that noninvasive ventilation, targeted to markedly reduce hypercapnia, significantly improves survival and reduces readmission in stable hypercapnic chronic obstructive pulmonary disease. The association of SDB with chronic diseases contributes to the high healthcare costs incurred by SDB patients. SDB also has an important negative impact on quality of life, which is reversed by CPAP treatment. The high prevalence of SDB, and its association with diseases that cause significant morbidity and mortality, suggest that the diagnosis and management of SDB is an important therapeutic goal. First, adherent CPAP treatment significantly improves the quality of life of all patients with SDB; second, it eliminates the negative impact of untreated SDB on any associated chronic diseases; and third, it significantly reduces the increased costs of all hospital and medical services directly associated with untreated SDB. In short, the recognition and treatment of SDB is vital for the continued health and wellbeing of individual patients with SDB.

Impact of sleep-disordered breathing in patients with acute myocardial infarction: a retrospective analysis

Sleep-disordered breathing (SDB) is associated with an increased risk of cardiovascular events. Previous studies showed that severe SDB has a negative impact on myocardial salvage and progression of left ventricular dysfunction after acute myocardial infarction (AMI). This study investigated the frequency of SDB and the effects of SDB on left ventricular function after AMI. This retrospective study enrolled all patients with AMI who had undergone cardiorespiratory polygraphy for SDB diagnosis. The apnea-hypopnea index was used as a standard metric of SDB severity. SDB was classified as mild (apnea-hypopnea index >5 to <15 per h), moderate (≥15 to <30 per h) or severe (apnea-hypopnea index ≥30 per h). According to the majority of events, SDB was classified as predominant obstructive sleep apnea, central sleep apnea or mixed sleep apnea (mixed SDB). A total of 223 patients with AMI (112 with ST elevation and 111 without ST elevation; 63.2 ± 11.2 years, 82% male, left ventricular ejection fraction 49 ± 12%) were enrolled. SDB was present in 85.6%, and was moderate-to-severe in 63.2%; 40.8% had obstructive sleep apnea, 41.7% had central sleep apnea and 3.1% had mixed SDB. Left ventricular ejection fraction was lower in patients with AMI with severe SDB (45 ± 14%) versus those without SDB (57 ± 7%; P < 0.005). In addition, lower left ventricular ejection fraction (≤45%) was associated with increased frequency (apnea-hypopnea index ≥5 per h in 96%) and severity (apnea-hypopnea index ≥30 per h in 48%) of SDB in general and a higher percentage of central sleep apnea (57%) in particular. SDB is highly frequent in patients with AMI. SDB severity appeared to be linked to impaired left ventricular function, especially in patients with central sleep apnea.

Predictors of obstructive sleep apnoea in patients admitted for acute coronary syndrome

Identifying undiagnosed obstructive sleep apnoea (OSA) patients in cardiovascular clinics could improve their management. Aiming to build an OSA predictive model, a broad analysis of clinical variables was performed in a cohort of acute coronary syndrome (ACS) patients.

Sociodemographic, anthropometric, life-style and pharmacological variables were recorded. Clinical measures included blood pressure, electrocardiography, echocardiography, blood count, troponin levels and a metabolic panel. OSA was diagnosed using respiratory polygraphy. Logistic regression models and classification and regression trees were used to create predictive models.

A total of 978 patients were included (298 subjects with apnoea–hypopnoea index (AHI) <15 events·h−1and 680 with AHI ≥15 events·h−1). Age, BMI, Epworth sleepiness scale, peak troponin levels and use of calcium antagonists were the main determinants of AHI ≥15 events·h−1(C statistic 0.71; sensitivity 94%; specificity 24%). Age, BMI, blood triglycerides, peak troponin levels and Killip class ≥II were determinants of AHI ≥30 events·h−1(C statistic of 0.67; sensitivity 31%; specificity 86%).

Although a set of variables associated with OSA was identified, no model could successfully predict OSA in patients admitted for ACS. Given the high prevalence of OSA, the authors propose respiratory polygraphy as a to-be-explored strategy to identify OSA in ACS patients.

Prevalence of sleep-disordered breathing in acute coronary syndrome: a systemic review and meta-analysis

PURPOSE

This study aimed to review the literature on the prevalence of sleep-disordered breathing (SDB) in patients with acute coronary syndrome (ACS).

METHODS

Relevant studies were searched on PubMed, EMBASE, and Cochrane Library through December 2014. Data were extracted using standardized forms. Pooled prevalence of all SDB (apnea-hypopnea index (AHI) > 5), moderate-to-severe SDB (AHI > 15), and severe SDB (AHI > 30) in ACS patients was calculated using DerSimonian-Laird random-effects model. Sensitivity analysis was performed based on races and diagnostic methods of SDB.

RESULTS

A total of 32 studies were included in the present meta-analysis, examining 3360 patients. The meta-analysis indicated that pooled prevalence of all SDB (AHI > 5), moderate-to-severe SDB (AHI > 15), and severe SDB (AHI > 30) in ACS patients were 69 % (95 % confidence interval (CI) = 61, 77 %), 43 % (95 % CI = 36, 49 %), and 25 % (95 % CI = 17, 33 %), respectively. Sensitivity analysis indicated that the pooled prevalence of SDB in Western population was similar to that in Asian population. However, diagnostic methods of SDB seemed to have various impacts on the prevalence of all SDB (AHI > 5), moderate-to-severe SDB (AHI > 15), and severe SDB (AHI > 30).

CONCLUSIONS

High prevalence of all SDB, moderate-to-severe SDB, and severe SDB was found in ACS patients. It is clinically important to screen for SDB in patients with ACS.

Effects of Ethnicity on the Prevalence of Obstructive Sleep Apnoea in Patients with Acute Coronary Syndrome: A Pooled Analysis of the ISAACC Trial and Sleep and Stent Study

BACKGROUND

Obstructive sleep apnoea (OSA) is an emerging risk factor for acute coronary syndrome (ACS). We sought to determine the effects of ethnicity on the prevalence of OSA in patients presenting with ACS who participated in an overnight sleep study.

METHODS

A pooled analysis using patient-level data from the ISAACC Trial and Sleep and Stent Study was performed. Using the same portable diagnostic device, OSA was defined as an apnoea-hypopnoea index of ≥15 events per hour.

RESULTS

A total of 1961 patients were analysed, including Spanish (53.6%, n=1050), Chinese (25.5%, n=500), Indian (12.0%, n=235), Malay (6.1%, n=119), Brazilian (1.7%, n=34) and Burmese (1.2%, n=23) populations. Significant differences in body mass index (BMI) were found among the various ethnic groups, averaging from 25.3kg/m² for Indians and 25.4kg/m² for Chinese to 28.6kg/m² for Spaniards. The prevalence of OSA was highest in the Spanish (63.1%), followed by the Chinese (50.2%), Malay (47.9%), Burmese (43.5%), Brazilian (41.2%), and Indian (36.1%) patients. The estimated odds ratio of BMI on OSA was highest in the Chinese population (1.17; 95% confidence interval: 1.10-1.24), but was not significant in the Spanish, Burmese or Brazilian populations. The area under the curve (AUC) for the Asian patients (ranging from 0.6365 to 0.6692) was higher than that for the Spanish patients (0.5161).

CONCLUSION

There was significant ethnic variation in the prevalence of OSA in patients with ACS. The magnitude of the effect of BMI on OSA was greater in the Chinese population than in the Spanish patients.

Sleep quality and adverse outcomes for patients with acute myocardial infarction

AIMS AND OBJECTIVES

This study aimed to analyse the relationship between the worsening of clinical outcomes (cardiovascular death, recurrent cardiovascular ischaemic events and stroke) and sleep quality, daytime sleepiness and risk for obstructive sleep apnoea syndrome in patients admitted to cardiac care units due to an acute myocardial infarction.

BACKGROUND

There is evidence that sleep disorders can contribute to the worsening of cardiovascular diseases.

DESIGN

This is a descriptive study with follow-up.

METHODS

Data collection was conducted in a large university hospital in Brazil from October 2013 to March 2014. Patients admitted with acute myocardial infarction provided data about sleep quality, daytime sleepiness and risk factors for obstructive sleep apnoea syndrome by answering specific questionnaires. Clinical data were obtained from medical charts. Data were analysed with descriptive statistics and multiple logistic regression models.

RESULTS

The worsening of clinical outcome occurred in 12·4% of patients and was independently associated to poor sleep quality.

CONCLUSION

Poor sleep quality, excessive daytime sleepiness and high risk for obstructive sleep apnoea syndrome were frequent in hospitalised patients with acute myocardial infarction and affect negatively the process of recovery.

RELEVANCE TO CLINICAL PRACTICE

It is important to evaluate sleep quality and sleep disorders, aiming at preventing and reducing unfavourable outcomes of cardiovascular disease, particularly for acute myocardial infarction patients.

Nocturnal Hypoxemia Due to Obstructive Sleep Apnea Is an Independent Predictor of Poor Prognosis After Myocardial Infarction

Background

Obstructive sleep apnea (OSA) is an important risk factor for the development of cardiovascular diseases including myocardial infarction (MI). The aim of this study was to investigate the effects of OSA on prognosis after MI, and to determine which specific measures of OSA severity best predicted outcomes.

Methods and Results

We performed a prospective study, in which 112 patients without a prior diagnosis of sleep apnea underwent comprehensive polysomnography within a median of 7 days after MI. Patients were followed up at 6‐monthly intervals (±2 weeks) for a total of 48 months. Patients classified with central apnea (n=6) or those using continuous positive airway pressure (n=8) after polysomnography were excluded from analyses. The primary end point was major adverse cardiac events, including death from any cause, recurrent MI, unstable angina, heart failure, stroke, and significant arrhythmic events. Forty of 98 patients (41%) had OSA (apnea‐hypopnea index ≥15 events/h). OSA patients had higher major adverse cardiac event rates when compared to those without OSA (47.5% versus 24.1%; χ²=5.41, P=0.020). In a multivariate model that adjusted for clinically relevant variables including age, left ventricular ejection fraction, diabetes mellitus, oxygen desaturation index, and arousal index, significant hypoxemia, as defined by nocturnal nadir oxygen saturation ≤85%, was an independent risk factor for major adverse cardiac events (hazard ratio=6.05, P=0.004) in follow‐up 15 months after baseline.

Conclusions

Nocturnal hypoxemia in OSA is an important predictor of poor prognosis for patients after MI. These findings suggest that routine use of low‐cost nocturnal oximetry may be an economical and practical approach to stratify risk in post‐MI patients.

The Association between Nocturnal Cardiac Arrhythmias and Sleep-Disordered Breathing: The DREAM Study

STUDY OBJECTIVES

To determine whether sleep-disordered breathing (SDB) is associated with cardiac arrhythmia in a clinic-based population with multiple cardiovascular comorbidities and severe SDB.

METHODS

This was a cross-sectional analysis of 697 veterans who underwent polysomnography for suspected SDB. SDB was categorized according to the apnea-hypopnea index (AHI): none (AHI < 5), mild (5 ≥ AHI < 15), and moderate-severe (AHI ≥ 15). Nocturnal cardiac arrhythmias consisted of: (1) complex ventricular ectopy, (CVE: non-sustained ventricular tachycardia, bigeminy, trigeminy, or quadrigeminy), (2) combined supraventricular tachycardia, (CST: atrial fibrillation or supraventricular tachycardia), (3) intraventricular conduction delay (ICD), (4) tachyarrhythmias (ventricular and supraventricular), and (5) any cardiac arrhythmia. Unadjusted, adjusted logistic regression, and Cochran-Armitage testing examined the association between SDB and cardiac arrhythmias. Linear regression models explored the association between hypoxia, arousals, and cardiac arrhythmias.

RESULTS

Compared to those without SDB, patients with moderate-severe SDB had almost three-fold unadjusted odds of any cardiac arrhythmia (2.94; CI 95%, 2.01-4.30; p < 0.0001), two-fold odds of tachyarrhythmias (2.16; CI 95%,1.47-3.18; p = 0.0011), two-fold odds of CVE (2.01; 1.36-2.96; p = 0.003), and two-fold odds of ICD (2.50; 1.58-3.95; p = 0.001). A linear trend was identified between SDB severity and all cardiac arrhythmia subtypes (p value linear trend < 0.0001). After adjusting for age, BMI, gender, and cardiovascular diseases, moderate-severe SDB patients had twice the odds of having nocturnal cardiac arrhythmias (2.24; 1.48-3.39; p = 0.004). Frequency of obstructive respiratory events and hypoxia were strong predictors of arrhythmia risk.

CONCLUSIONS

SDB is independently associated with nocturnal cardiac arrhythmias. Increasing severity of SDB was associated with an increasing risk for any cardiac arrhythmia.

The Link Between Obstructive Sleep Apnea and Cardiovascular Disease

Obstructive sleep apnea (OSA) is common in the general population and highly prevalent in patients with cardiovascular disease. In this paper, we review (1) the pathophysiological mechanisms of OSA that may causally contribute to cardiovascular disease; (2) current evidence regarding the association between OSA and hypertension, stroke, ischemic heart disease, heart failure, atrial fibrillation, and cardiovascular mortality; and (3) the impact of continuous positive airway pressure (CPAP) treatment on cardiovascular risk factors and outcomes. We emphasize the importance of obesity as a comorbidity of OSA and a confounder in the association between OSA and cardiovascular disease. We also discuss the importance of addressing obesity in patients with OSA, as a strategy to reduce the burden of cardiovascular risk factors in this population. Implications for the approach of patients' OSA in clinical practice and future research directions are discussed.

Roles and Mechanisms of Obstructive Sleep Apnea-Hypopnea Syndrome and Chronic Intermittent Hypoxia in Atherosclerosis: Evidence and Prospective

The morbidity and mortality of obstructive sleep apnea-hypopnea syndrome (OSAHS) are regarded as consequences of its adverse effects on the cardiovascular system. Chronic intermittent hypoxia (CIH) induced by OSAHS can result in vascular endothelial injury, thus promoting development of atherosclerosis (AS). Studies have shown that CIH is an independent risk factor for the occurrence and development of AS, but the underlying mechanism remains unclear. Here, we review clinical and fundamental studies reported during the last 10 years on the occurrence and development of AS mediated by CIH, focusing on inflammation, oxidative stress, insulin resistance, cell apoptosis, vascular endothelial injury, platelet activation, and neuroendocrine disorders. This review will offer current evidence and perspective to researchers for the development of effective intervention strategies for OSAHS-related cardiocerebrovascular diseases.

Obstructive Sleep Apnea and Cardiovascular Events After Percutaneous Coronary Intervention

BACKGROUND

There is a paucity of data from large cohort studies examining the prognostic significance of obstructive sleep apnea (OSA) in patients with coronary artery disease. We hypothesized that OSA predicts subsequent major adverse cardiac and cerebrovascular events (MACCEs) in patients undergoing percutaneous coronary intervention.

METHODS AND RESULTS

The Sleep and Stent Study was a prospective, multicenter registry of patients successfully treated with percutaneous coronary intervention in 5 countries. Between December 2011 and April 2014, 1748 eligible patients were prospectively enrolled. The 1311 patients who completed a sleep study within 7 days of percutaneous coronary intervention formed the cohort for this analysis. Drug-eluting stents were used in 80.1% and bioresorbable vascular scaffolds in 6.3% of the patients, and OSA, defined as an apnea-hypopnea index of ≥15 events per hour, was found in 45.3%. MACCEs, a composite of cardiovascular mortality, nonfatal myocardial infarction, nonfatal stroke, and unplanned revascularization, occurred in 141 patients during the median follow-up of 1.9 years (interquartile range, 0.8 years). The crude incidence of an MACCEs was higher in the OSA than the non-OSA group (3-year estimate, 18.9% versus 14.0%; p=0.001). Multivariate Cox regression analysis indicated that OSA was a predictor of MACCEs, with an adjusted hazard ratio of 1.57 (95% confidence interval, 1.10-2.24; P=0.013), independently of age, sex, ethnicity, body mass index, diabetes mellitus, and hypertension.

CONCLUSIONS

OSA is independently associated with subsequent MACCEs in patients undergoing percutaneous coronary intervention. Evaluation of therapeutic approaches to mitigate OSA-associated risk is warranted.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01306526.