Sleep apnoea and cardiovascular outcomes after coronary artery bypass grafting

Sleep apnea prevalence and severity after coronary revascularization versus no intervention: a systematic review & meta-analysis

PURPOSE

Obstructive sleep apnea (OSA) is a common disease in patients with coronary artery disease (CAD). Approximately 40-80% of cardiovascular disease patients have obstructive sleep apnea. The manifestation of it can vary significantly in different types of CAD patients. This systematic review and meta-analysis investigate the prevalence and severity of OSA in patients with acute coronary syndrome (ACS).

METHODS

This systematic review was conducted according to PRISMA guidelines. The first inclusion criteria were that a reliable sleep study had to be done after treating the patients' acute coronary incident. All patients in the studies included were adults suffering from an ACS who underwent either coronary artery bypass grafting surgery (CABG), a percutaneous coronary intervention (PCI) or had no invasive coronary intervention done. A search was conducted within four valid databases 27.1.2023 and all suitable articles published after 1.1.2010 were included.

RESULTS

Eight studies fulfilled the full inclusion criteria. In five of them, a sleep study had been performed after PCI, in two after no coronary intervention, and in one study after CABG. Mean AHI in no-OSA group after PCI was 9.5 /h (95% CI 5.3-13.7) and in the no intervention group 6.4 /h (95% CI 3.5-9.4). In OSA patients, mean AHI after PCI was 34.9 /h (95% CI 25.9-43.8) vs. 24.1 /h without intervention (95% CI 15.6-32.6).

CONCLUSIONS

Sleep apnea is very common among ACS patients and should be screened for and addressed after the acute coronary intervention. Moreover, we found that OSA is more severe in patients in whom PCI for ACS was indicated as opposed to patients who underwent no coronary intervention.

Bidirectional association of sleep disorders with chronic kidney disease: a systematic review and meta-analysis

Background

Published studies have suggested a link between chronic kidney disease (CKD) and sleep disorders, although the exact nature of this association has not been uniformly described. Clarifying this relationship may facilitate evidence-based interventions that address the interplay between these disease entities. Such interventions could prevent obstructive sleep apnea (OSA) from worsening CKD and improve the quality of life for CKD patients by reducing the risk of developing OSA. Therefore, the objective of this meta-analysis is to assess the bidirectional association between sleep disorders and CKD.

Methods

Following a PROSPERO-registered protocol, three blinded reviewers conducted a systematic review of the Medline/PubMed, Embase, Cochrane Library and Cumulative Index of Nursing and Allied Health (CINAHL) databases for observational studies pertaining to the relationship between sleep disorders and CKD. A meta-analysis was conducted in risk ratios (RRs).

Results

From 63 studies (26 777 524 patients), OSA [RR 1.68; 95% confidence interval (CI) 1.45 to 1.93], albuminuria (RR 1.54; 95% CI 1.18 to 1.99), restless leg syndrome (RLS) (RR 1.88; 95% CI 1.48 to 2.38) and insomnia (RR 1.24; 95% CI 1.01 to 1.54) were significantly associated with CKD. There was a significant association between OSA (RR 1.77; 95% CI 1.56 to 2.01) with incident CKD. There was a significant association of OSA (RR 1.74; 95% CI 1.55 to 1.96), RLS (RR 1.73; 95% CI 1.32 to 2.25) and insomnia (RR 1.14; 95% CI 1.03 to 1.27) in patients with CKD compared with healthy controls. CKD was also significantly associated with incident OSA (RR 1.60; 95% CI 1.35 to 1.89).

Conclusion

The bidirectional associations of obstructive sleep apnea with CKD remained consistent across different stages of CKD, modes of diagnosis of sleep disorder and geographical region. A bidirectional association was observed between CKD and obstructive sleep apnea, RLS and insomnia. The treatment of sleep disorders may reduce the risk of CKD, and vice versa.

Sleep apnea in patients undergoing coronary artery bypass grafting: Impact on perioperative outcomes

Sleep-disordered breathing is common in patients with coronary artery disease undergoing coronary artery bypass grafting. Sleep-disordered breathing is associated with increased perioperative morbidity, arrhythmias (e.g. atrial fibrillation) and mortality. This study investigated the impact of sleep-disordered breathing on the postoperative course after coronary artery bypass grafting, including development of atrial fibrillation. This prospective single-centre cohort study included adults undergoing coronary artery bypass grafting. All were screened for sleep-disordered breathing (polygraphy) and atrial fibrillation (electrocardiogram) preoperatively; those with known sleep-disordered breathing or atrial fibrillation were excluded. Endpoints included new-onset atrial fibrillation, duration of mechanical ventilation, time in the intensive care unit, and postoperative infection. Regression analysis was performed to identify associations between sleep-disordered breathing and these outcomes. A total of 508 participants were included (80% male, median age 68 years). The prevalence of any (apnea-hypopnea index ≥ 5 per hr), moderate (apnea-hypopnea index = 15-30 per hr) and severe (apnea-hypopnea index > 30 per hr) sleep-disordered breathing was 52.9%, 9.3% and 10.2%, respectively. All-cause 30-day mortality was 0.98%. After adjustment for age and sex, severe sleep-disordered breathing was associated with longer respiratory ventilation support (crude odds ratio [95% confidence interval] 5.28 [2.18-12.77]; p < 0.001) and higher postoperative infection rates (crude odds ratio 3.32 [1.45-7.58]; p < 0.005), but not new-onset atrial fibrillation or mortality. New-onset atrial fibrillation was significantly associated with postoperative infection and prolonged hospital stay. The significant associations between sleep-disordered breathing and several adverse outcomes after coronary artery bypass grafting support the need for preoperative sleep-disordered breathing screening in individuals undergoing cardiac surgery.

Obstructive sleep apnea and temporal changes in cardiac repolarization in patients undergoing coronary artery bypass grafting

STUDY OBJECTIVES

In coronary artery bypass grafting (CABG), abnormal cardiac repolarization is associated with adverse cardiovascular events that can be measured via the QTc interval. We investigated the impact of obstructive sleep apnea on the change in repolarization after CABG and the association of change in repolarization with the occurrence of major adverse cardiac and cerebrovascular events.

METHODS

A total of 1,007 patients from 4 hospitals underwent an overnight sleep study prior to a nonemergent CABG. Electrocardiograms of 954 patients (median age: 62 years; male: 86%; mean follow-up: 2.1 years) were acquired prospectively within 48 hours before CABG (T1) and within 24 hours after CABG (T2). QTc intervals were measured using the BRAVO algorithm by Analyzing Medical Parameters for Solutions LLC. The change in T2 from T1 for QTc (ΔQTc) was derived, and Cox regression was performed.

RESULTS

Compared with those without, patients who developed major adverse cardiac and cerebrovascular events (n = 115) were older and had (1) a higher prevalence of smoking, hypertension, diabetes mellitus, and chronic kidney disease; (2) a higher apnea-hypopnea index and oxygen desaturation index; and (3) a smaller ΔQTc. Cox regression analysis demonstrated a smaller ΔQTc to be an independent risk factor for major adverse cardiac and cerebrovascular events (hazard ratio: 0.997; P = .032). In the multivariable regression model, a higher oxygen desaturation index was independently associated with a smaller ΔQTc (correlation coefficient: -0.58; P < .001).

CONCLUSIONS

A higher preoperative oxygen desaturation index was an independent predictor of a smaller ΔQTc. ΔQTc within 24 hours after CABG could be a novel predictor of occurrence of major adverse cardiac and cerebrovascular events at medium-term follow-up.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Name: Undiagnosed Sleep Apnea and Bypass OperaTion (SABOT); URL: https://classic.clinicaltrials.gov/ct2/show/NCT02701504; Identifier: NCT02701504.

CITATION

Teo YH, Yong CL, Ou YH, et al. Obstructive sleep apnea and temporal changes in cardiac repolarization in patients undergoing coronary artery bypass grafting. J Clin Sleep Med. 2024;20(1):49-55.

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.

Obstructive sleep apnoea and coronary revascularisation outcomes

Obstructive sleep apnoea (OSA) is a chronic sleep disorder characterised by recurrent cyclical episodes of upper airway collapse causing apnoea or hypopnoea. Despite being highly prevalent in patients with cardiovascular conditions, OSA has been a neglected component in cardiovascular practice. Fortunately, in the past few decades, increasing acknowledgement of the vulnerability of cardiac patients to OSA-related stressors and its adverse cardiovascular outcomes has made it a recognised cardiovascular risk factor in practice guidelines. Consequences of OSA include oxidative stress, endothelial dysfunction, autonomic dysfunction, and increased catecholamine release. The perturbations caused by OSA not only provide a clear mechanistic link to cardiovascular disease but also to poor outcomes after coronary revascularisation. This review article focuses on the correlation of OSA to coronary revascularisation outcomes. Our team reported that OSA is present in approximately 50% of patients undergoing coronary revascularisation. Importantly, untreated OSA was found to be an independent predictor of adverse events after both percutaneous coronary intervention and coronary artery bypass grafting. Although randomised trials did not confirm the benefits of OSA treatment in improving cardiovascular outcomes, these early trials were limited by poor treatment adherence. For now, systematic screening for OSA in patients undergoing coronary revascularisation is not indicated. Yet, with the proven benefit of OSA treatment in improving blood pressure control and quality of life, screening for and treatment of OSA is still indicated if patients have reported excessive daytime sleepiness and/or suboptimally controlled hypertension.

The Belun sleep platform to diagnose obstructive sleep apnea in patients with hypertension and high cardiovascular risk

STUDY OBJECTIVE

Current hypertension guidelines recommend that at-risk individuals be screened for obstructive sleep apnea (OSA). The Belun Ring is a wearable OSA diagnostic device worn on the palmar side of the proximal phalanx of the index finger.

METHODS

We recruited 129 participants (age: 60 ± 8 years, male sex: 88%, BMI: 27 ± 4 kg/m 2 ) with hypertension and high cardiovascular risk for a simultaneous polysomnography and Belun Ring monitoring for one night. Epworth Sleepiness Scale score more than 10 was detected in 27 (21.0%) participants.

RESULTS

In the 127 participants who completed the study, the apnea-hypopnea index (AHI) derived from polysomnography was 18.1 (interquartile range: 33.0) events/h and that derived from the Belun Ring was 19.5 (interquartile range: 23.3) events/h [intraclass correlation coefficient: 0.882, 95% confidence interval (95% CI): 0.837-0.916]. A Bland-Altman plot showed the difference between the Belun Ring and polysomnography AHIs to be -1.3 ± 10.4 events/h. Area under the receiver operating characteristic for the Belun Ring AHI was 0.961 (95% CI: 0.932-0.990, P  < 0.001). When the Belun Ring AHI of at least 15 events/h was used to diagnose OSA, the sensitivity, specificity, positive predictive value, and negative predictive value were 95.7, 77.6, 85.3, and 93.8%, respectively. The overall accuracy was 87.4%. The Cohen's kappa agreement was 0.74 ± 0.09 ( P  < 0.001). Similar results were obtained when the oxygen desaturation index was used to diagnose OSA.

CONCLUSION

A high prevalence of OSA was detected in patients with hypertension and high cardiovascular risk. The Belun Ring is a reliable device for OSA diagnosis similar to polysomnography.

Asian Pacific Society of Cardiology Consensus Statements on the Diagnosis and Management of Obstructive Sleep Apnoea in Patients with Cardiovascular Disease

Obstructive sleep apnoea (OSA) is strongly associated with cardiovascular disease (CVD). However, evidence supporting this association in the Asian population is scarce. Given the differences in the epidemiology of CVD and cardiovascular risk factors, as well as differences in the availability of healthcare resources between Asian and Western countries, an Asian Pacific Society of Cardiology (APSC) working group developed consensus recommendations on the management of OSA in patients with CVD in the Asia-Pacific region. The APSC expert panel reviewed and appraised the available evidence using the Grading of Recommendations Assessment, Development, and Evaluation system. Consensus recommendations were developed and put to an online vote. Consensus was reached when 80% of votes for a given recommendation were in support of ‘agree’ or ‘neutral.’ The resulting statements provide guidance on the assessment and treatment of OSA in patients with CVD in the Asia-Pacific region. The APSC hopes for these recommendations to pave the way for screening, early diagnosis and treatment of OSA in the Asia-Pacific region.

Obstructive sleep apnea therapy for cardiovascular risk reduction-Time for a rethink?

Obstructive sleep apnea (OSA) is a highly prevalent and underdiagnosed medical condition, which is associated with various cardiovascular and metabolic diseases. The current mainstay of therapy is continuous positive airway pressure (CPAP); however, CPAP is known to be poorly accepted and tolerated by patients. In randomized controlled trials evaluating CPAP in cardiovascular outcomes, the average usage was less than 3.5 hours, which is below the 4 hours per night recommended to achieve a clinical benefit. This low adherence may have resulted in poor effectiveness and failure to show cardiovascular risk reduction. The mandibular advancement device (MAD) is an intraoral device designed to advance the mandible during sleep. It functions primarily through alteration of the jaw and/or tongue position, which results in improved upper airway patency and reduced upper airway collapsibility. The MAD is an approved alternative therapy that has been consistently shown to be the preferred option by patients who are affected by OSA. Although the MAD is less efficacious than CPAP in abolishing apnea and hypopnea events in some patients, its greater usage results in comparable improvements in quality-of-life and cardiovascular measures, including blood pressure reduction. This review summarizes the impact of OSA on cardiovascular health, the limitations of CPAP, and the potential of OSA treatment using MADs in cardiovascular risk reduction.

Sleep apnea and recurrent heart failure hospitalizations after coronary artery bypass grafting

STUDY OBJECTIVES

Sleep apnea is prevalent in patients undergoing coronary artery bypass grafting (CABG). We investigated the relationship between sleep apnea and recurrent heart failure hospitalizations in patient undergoing non-urgent CABG.

METHODS

Between November 2013 and December 2018, 1007 patients completed a sleep study prior to CABG and were followed up until April 2020. Recurrent heart failure hospitalizations were analyzed by Poisson, negative binomial, Andersen-Gill, and joint frailty models, with partial and full adjustment for covariates.

RESULTS

At an average follow-up of 3.3 years, the number of patients with 0, 1, or ≥2 heart failure hospitalizations were 908 (90.2%), 62 (6.2%), and 37 (3.7%), respectively. The total number of heart failure hospitalizations was 179, comprising 62 (35%) first and 117 (65%) repeat events. The numbers of heart failure hospitalizations for the sleep apnea (n = 513, 50.9%) and non-sleep apnea groups were 127 and 52, respectively. Negative binomial regression demonstrated that sleep apnea was associated with recurrent heart failure hospitalizations (fully adjusted rate ratio, 1.71; 95% confidence interval [CI], 1.12-2.62; p = 0.013). Similar results were found in Poisson (1.63; 95%CI, 1.15-2.31; p = 0.006), Andersen-Gill (1.66; 95% CI, 1.01-2.75; p = 0.047), and joint frailty models (1.72; 95% CI, 1.00-3.01; p = 0.056).

CONCLUSIONS

In patients after CABG, repeat events accounted for two-thirds of heart failure hospitalizations. Sleep apnea was independently associated with recurrent heart failure hospitalizations.

Obstructive sleep apnea increases heart rhythm disorders and worsens subsequent outcomes in elderly patients with subacute myocardial infarction

OBJECTIVE

Obstructive sleep apnea (OSA) is a potential cardiovascular risk. We aimed to investigate the association of OSA with heart rhythm disorders and prognosis in elderly patients with new-onset acute myocardial infarction (AMI).

METHODS

We prospectively enrolled 252 AMI elderly patients (mean age, 68.5 ± 6.9 years) who were undergoing revascularization and completed a sleep study during their hospitalization. All subjects were categorized into non-OSA (apnea–hypopnea index (AHI) < 15, n = 130) and OSA (AHI ≥ 15, n = 122) groups based on the AHI. The changes in the autonomic nervous system, incidence of arrhythmia during nocturnal sleep, and major adverse cardiovascular and cerebrovascular events (MACCEs) were compared between the groups.

RESULTS

The mean AHI value in all AMI patients was 22.8 ± 10.9. OSA patients showed higher levels of body mass index and peak high-sensitivity C-reactive protein and lower levels of minimum nocturnal oxygen saturation (MinSaO₂), as well as greater proportion of multivessel coronary artery disease (all P < 0.05). The OSA group also showed significant increases in heart rate variability and heart rate turbulence onset (both P < 0.05) and higher incidence of arrhythmia (including sinus, atrial, and ventricular in origin). At a median follow-up of 6 months (mean 0.8–1.6 years), OSA (AHI ≥ 15) combined with hypoxia (MinSaO ₂ ≤ 80%) was independently associated with the incidence of MACCEs (hazard ratio [HR]: 4.536; 95% confidence interval [CI]: 1.461−14.084,P = 0.009) after adjusting for traditional risk factors.

CONCLUSIONS

OSA and OSA-induced hypoxia may correlate with the severity of myocardial infarction, increase the occurrence of heart rhythm disorders in elderly subacute MI patients, and worsen their short-term poor outcomes.

Sleep apnea and diabetes mellitus are independently associated with cardiovascular events and hospitalization for heart failure after coronary artery bypass grafting

The relative and combined effects of sleep apnea with diabetes mellitus (DM) on cardiovascular outcomes in patients undergoing coronary artery bypass grafting (CABG) remain unknown. In this secondary analysis of data from the SABOT study, 1007 patients were reclassified into four groups based on their sleep apnea and DM statuses, yielding 295, 218, 278, and 216 patients in the sleep apnea (+) DM (+), sleep apnea (+) DM (−), sleep apnea (−) DM (+), and sleep apnea (−) DM (−) groups, respectively. After a mean follow-up period of 2.1 years, the crude incidence of major adverse cardiac and cerebrovascular event was 18% in the sleep apnea (+) DM (+), 11% in the sleep apnea (+) DM (−), 13% in the sleep apnea (−) DM (+), and 5% in the sleep apnea (−) DM (−) groups. Using sleep apnea (−) DM (−) as the reference group, a Cox regression analysis indicated that sleep apnea (+) and DM (+) independently predicted MACCEs (adjusted hazard ratio, 3.2; 95% confidence interval, 1.7–6.2; p = 0.005) and hospitalization for heart failure (adjusted hazard ratio, 12.6; 95% confidence interval, 3.0–52.3; p < 0.001). Sleep apnea and DM have independent effects on the prognosis of patients undergoing CABG.

Clinical trial registration: ClinicalTrials.gov identification no. NCT02701504.

The Emerging Role of Drug-Induced Sleep Endoscopy in the Management of Obstructive Sleep Apnea

Obstructive sleep apnea is a prevalent sleep disorder characterized by partial or complete obstruction of the upper airway. Continuous positive airway pressure is the first-line therapy for most patients, but adherence is often poor. Alternative treatment options such as mandibular advancement devices, positional therapy, and surgical interventions including upper airway stimulation target different levels and patterns of obstruction with varying degrees of success. Drug-induced sleep endoscopy enables the visualization of upper airway obstruction under conditions mimicking sleep. In the era of precision medicine, this additional information may facilitate better decision-making when prescribing alternative treatment modalities, with the hope of achieving better adherence and/or success rates. This review discusses the current knowledge and evidence on the role of drug-induced sleep endoscopy in the non-positive airway pressure management of obstructive sleep apnea.