Sleep disordered breathing in patients with acute coronary syndromes

Central Sleep Apnea and Cardiovascular Disease State-of-the-Art

Central sleep apnea (CSA), a rare polysomnographic finding in the general population, is prevalent in certain cardiovascular conditions including systolic and diastolic left ventricular dysfunction, atrial fibrillation, coronary artery disease, carotid artery stenosis, stroke and use of certain cardiac-related medications. Polysomnographic findings of CSA with adverse cardiovascular impacts include nocturnal hypoxemia and arousals, which can lead to increased sympathetic activity both at night and in the daytime. Among cardiovascular diseases, CSA is most prevalent in patients with left ventricular systolic dysfunction; a large study of more than 900 treated patients has shown a dose dependent relationship between nocturnal desaturation and mortality. Multiple small randomized controlled trials have shown mitigation of sympathetic activity when CSA is treated with nocturnal oxygen, continuous positive airway pressure and adaptive servoventilation. However, two early randomized controlled trials with positive airway pressure devices have shown either neutral effect on survival or excess premature mortality in the active treatment arm, compared to untreated CSA. In contrast, the results of the most recent trial using an advanced adaptive servoventilation device showed improved quality of life and no signal for mortality suggesting that treatment of CSA was at least safe. In addition to positive airway pressure devices, multiple medications have been shown to improve CSA, but no long-term trials of pharmacologic therapy have been published. Currently, phrenic nerve stimulation is approved for treatment of CSA, and the results of a randomized controlled trial showed significant improvement in sleep metrics and quality of life.

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.

The Great Controversy of Obstructive Sleep Apnea Treatment for Cardiovascular Risk Benefit: Advancing the Science Through Expert Consensus. An Official American Thoracic Society Workshop Report

The prevalence of obstructive sleep apnea (OSA) is on the rise, driven by various factors including more sensitive diagnostic criteria, increased awareness, enhanced technology through at-home testing enabling easy and cost-effective diagnosis, and a growing incidence of comorbid conditions such as obesity. Treating symptomatic patients with OSA syndrome to enhance quality of life remains a cornerstone approach. However, there is a lack of consensus regarding treatment to improve cardiovascular disease (CVD) outcomes, particularly in light of overall negative results from several randomized controlled trials (RCT) indicating no benefit of positive airway pressure (PAP) therapy on primary and secondary CVD events. These RCTs were limited by suboptimal PAP adherence, use of composite CVD outcomes, and limited diversity and generalizability to Sleep Clinic patients. As such, this workshop assembled clinical experts, as well as researchers in basic and translational science, epidemiology, clinical trials, and population health to discuss the current state, and future research directions to guide personalized therapeutic strategies and future research directions in OSA. There was overall consensus among workshop participants that OSA represents a heterogeneous disease with variable endotypes and phenotypes, and heterogeneous responses to treatment. Future research should prioritize employing multi-modal therapeutic approaches within innovative and adaptive trial designs, focusing on specific subgroups of OSA patients hypothesized to benefit from a CVD perspective. Future work should also be inclusive of diverse populations and consider the life-course of OSA to better comprehend treatment strategies that can address the disproportionate impact of OSA on racially minoritized groups. Further, a more holistic approach to sleep must be adopted to include broader assessments of symptoms, sleep duration, and comorbid sleep and circadian disorders. Finally, it is imperative to establish a sleep research consortium dedicated to collecting raw data and biospecimens categorized by OSA subtypes. This will facilitate mechanistic determinations, foster collaborative research, and help bolster the pipeline of early-career researchers.

Impact of Obstructive Sleep Apnea Syndrome on Ventricular Remodeling after Acute Myocardial Infarction: A Proof-of-Concept Study

Background: Obstructive sleep apnea syndrome (OSA) is common in patients with acute myocardial infarction (AMI). Whether OSA impacts on the ventricular remodeling post-AMI remains unclear. We compared cardiac ventricular remodeling in patients assessed by cardiac magnetic resonance (CMR) imaging at baseline and six months after AMI based on the presence and severity of OSA. Methods: This prospective study included 47 patients with moderate to severe AMI. They all underwent CMR at inclusion and at six months after an AMI, and a polysomnography was performed three weeks after AMI. Left and right ventricular remodeling parameters were compared between patients based on the AHI, AHI in REM and NREM sleep, oxygen desaturation index, and daytime sleepiness. Results: Of the 47 patients, 49% had moderate or severe OSA with an AHI ≥ 15/h. No differences were observed between these patients and those with an AHI < 15/h for left ventricular end-diastolic and end-systolic volumes at six months. No association was found for left and right ventricular remodeling parameters at six months or for the difference between baseline and six months with polysomnographic parameters of OSA severity, nor with daytime sleepiness. Conclusions: Although with a limited sample size, our proof-of-concept study does not report an association between OSA and ventricular remodeling in patients with AMI. These results highlight the complexity of the relationships between OSA and post-AMI morbi-mortality.

Obstructive sleep apnea and coronary artery disease: An unholy nexus or a holy alliance?

Coronary artery disease (CAD) is a significant cause of morbidity and mortality globally, and hypertension, dyslipidemia, diabetes mellitus, and smoking are major cardiovascular (CV) risk factors. Obstructive sleep apnea (OSA) and CAD share an exciting relationship, and recently, OSA has emerged as a non-traditional CV risk factor. OSA is characterized by episodic sleep state-dependent collapse of the upper airway, resulting in periodic reductions or cessations in ventilation, with consequent hypoxia, hypercapnia, or arousals from sleep. The oxidative stress and vascular inflammation resulting from the nocturnal hypoxia followed by reoxygenation cycles predispose the patients to the development of atherosclerotic cardiovascular disease (CVD). Untreated OSA is associated with long-term health consequences, including CVD, metabolic disorders, cognitive impairment, and depression. Paradoxically, some recent studies have reported that patients with OSA may suffer less severe CAD due to the development of collateral circulation due to repetitive hypoxia experienced due to OSA.

Association of Obstructive Sleep Apnea With the Risk of Repeat Adverse Cardiovascular Events in Patients With Newly Diagnosed Acute Coronary Syndrome: A Systematic Review and Meta-Analysis

BACKGROUND

The impact of obstructive sleep apnea (OSA) on subsequent cardiovascular events in patients with acute coronary syndrome (ACS) remains inconclusive.

AIM

Our aim was to systematically assess the relationship between preexisting OSA and adverse cardiovascular events in patients with newly diagnosed ACS by conducting a systematic review and meta-analysis.

METHODS

We systematically searched PubMed, EMBASE, and Cochrane library for studies published up to May 1, 2020, that reported any association between OSA and cardiovascular events in patients with newly diagnosed ACS. The main outcomes were a composite of all-cause or cardiovascular death, recurrent myocardial infarction, stroke, repeat revascularization, or heart failure. We conducted a pooled analysis using the random-effects model. We also performed subgroup, sensitivity, heterogeneity analysis, and the assessment of publication bias.

RESULTS

We identified 10 studies encompassing 3350 participants. The presence of OSA was associated with increased risk of adverse cardiovascular events in newly prognosed ACS (risk ratio [RR] 2.18, 95% confidence interval [CI]: 1.45-3.26, P < .001, I2 = 64%). Between-study heterogeneity was partially explained by a multicenter study (9 single-center studies, RR 2.33 95% CI 1.69-3.19, I2 =18%), and I2 remarkably decreased from 64% to 18%. Moreover, OSA significantly increased the incidence of repeat revascularization (8 studies) and heart failure (6 studies) in patients with newly diagnosed ACS.

CONCLUSION

Patients with preexisting OSA are at greater risk of subsequent cardiovascular events after onset of ACS. Further studies should investigate the treatment of OSA in patient with ACS.

Effect of Obstructive Sleep Apnea and CPAP Treatment on Cardiovascular Outcomes in Acute Coronary Syndrome in the RICCADSA Trial

We aimed to address the impact of OSA and its treatment with continuous positive airway pressure (CPAP) on major adverse cardiovascular and cerebrovascular events (MACCE) in patients with acute coronary syndrome (ACS). In this current analysis of the revascularized ACS subgroup (n = 353) of the Randomized Intervention with CPAP in Coronary Artery Disease and Obstructive Sleep Apnea (RICCADSA) trial (Trial Registry: ClinicalTrials.gov; No: NCT 00519597), participants with non-sleepy OSA (apnea-hypopnea-index [AHI] ≥ 15 events/h on a home sleep apnea testing, and Epworth Sleepiness Scale [ESS] score < 10; n = 171) were randomized to CPAP (n = 86) or no-CPAP (n = 85). The sleepy OSA patients (AHI ≥ 15 events/h and ESS ≥ 10) who were offered CPAP, and the ones with no-OSA (AHI < 5 events/h) were included in the observational arm. A post-hoc analysis was done to compare untreated OSA (no-CPAP; n = 78) and nonadherent sleepy/non-sleepy OSA (n = 96) with the reference group without OSA (n = 81). The primary endpoint (the first event of repeat revascularization, myocardial infarction, stroke or cardiovascular mortality) during a median 4.7-year follow-up was evaluated in time-dependent Cox proportional hazards models adjusted for confounding factors. The incidence of MACCE did not differ significantly in intention-to-treat population. On-treatment analysis showed a significant risk reduction in those who used CPAP for ≥4 vs. <4 h/day or did not receive treatment (adjusted hazard ratio [HR] 0.17; 95% confidence interval [CI] 0.03–0.81; p = 0.03). Compared with the reference group, nonadherent/untreated OSA was associated with an increased cardiovascular risk (adjusted HR 1.97, 95% CI 1.03–3.77; p = 0.04). We conclude that OSA is an independent risk factor for adverse cardiovascular outcomes in patients with ACS. CPAP treatment may reduce this risk, if the device is used at least 4 h/day.

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.

Prevalence of obstructive sleep apnoea in acute coronary syndrome patients: systematic review and meta-analysis

Background

Obstructive Sleep Apnoea (OSA) has been recognised as a risk factor for cardiovascular diseases such as hypertension and cardiovascular events such as acute coronary syndrome (ACS). Since it is also known to reduce exercise tolerance, it is important to establish the prevalence of OSA in ACS patients, particularly in those who are commencing cardiac rehabilitation (CR) programs.

Methods

Using PRISMA guidelines a systematic search was conducted in order to identify studies that objectively measured (using polysomnography or portable monitoring) the prevalence of OSA in ACS patients following hospital admission. A data extraction table was used to summarise study characteristics and the quality of studies were independently assessed using the Joanna Briggs Institute Prevalence Critical Appraisal Tool. Meta-analysis of the selected studies was conducted in order to estimate OSA prevalence as a function of the two main methods of measurement, the severity of OSA, and timing of the OSA assessment following ACS hospital admission.

Results

Pooled prevalence estimates of OSA using the “gold standard” polysomnography ranged from 22% for severe OSA to 70% for mild OSA, at any time after hospital admission. Similar prevalence estimates were obtained using portable monitoring, but interpretation of these results are limited by the significant heterogeneity observed among these studies.

Conclusions

Prevalence of OSA following ACS is high and likely to be problematic upon patient entry into CR programs. Routine screening for OSA upon program entry may be necessary to optimise effectiveness of CR for these patients.

Sleep Disturbances in Patients With Coronary Heart Disease: A Systematic Review

STUDY OBJECTIVES

Investigation into sleep and coronary heart disease (CHD) has predominantly been focused on sleep disturbances as a risk factor for developing CHD. Objectively measured and self-reported sleep at a patient level has only been sparsely and not systematically reported. Therefore, we set out to review the literature for studies using objectively measured and self-reported sleep in patients with CHD. The review focuses on patients with acute coronary syndrome (ACS) and stable CHD.

METHODS

A systematic review performed in four databases adhering to the PRISMA guidelines applying a qualitative synthesis of evidence.

RESULTS

Following ACS, we found sleep architecture to be significantly disturbed with changes normalizing over a period of up to 6 months. With increasing severity of CHD, sleep disturbances were more pronounced; however, the modulating effects of sleep-disordered breathing and ejection fraction on sleep in patients with CHD are conflicting. Overall, studies were predominantly cross-sectional in design and of low methodological quality. Polysomnography was the predominant outcome assessment tool and validated self-reported assessment tools were limited.

CONCLUSIONS

Future investigations in sleep and CHD applying both a longitudinal design and investigating objective and self-reported sleep assessments are warranted.

SYSTEMATIC REVIEW REGISTRATION

Registry: PROSPERO, Title: Sleep measures in relation to coronary heart disease: a systematic review, Identifier: CRD42017056377, URL: https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=56377.

Prognostic impact of residual SYNTAX score in patients with obstructive sleep apnea and acute coronary syndrome: a prospective cohort study

Background

There is a paucity of data from large prospective study evaluating the prognostic significance of the residual Synergy between percutaneous intervention with Taxus drug-eluting stents and cardiac surgery (SYNTAX) Score (rSS) in patients with obstructive sleep apnea (OSA) and Acute Coronary Syndrome (ACS).

Methods

ACS patients who undergoing percutaneous coronary angiography and completing a sleep study during hospitalization were prospectively enrolled. The baseline SYNTAX Score (bSS) and the rSS after revascularization were assessed. Complete revascularization (CR, rSS = 0) and incomplete revascularization (ICR, rSS > 0) were categorized. OSA (apnea hypopnea index, AHI ≥ 15) and non-OSA (AHI < 15) were grouped according to AHI. The primary endpoint of the study was major adverse cardiovascular and cerebrovascular events (MACCEs), defined as a composite of cardiovascular death, myocardial infarction, stroke, ischemia-driven revascularization, or hospitalization for UAP or heart failure.

Results

Overall, 752 patients were prospectively enrolled. At a median follow-up of 1 year, the incidence of MACCEs was significantly higher in the OSA than in the non-OSA group (hazard ratio [HR]:1.68; 95% confidence interval [CI]:1.04–2.72; P = .034). ICR was associated with a higher risk of MACCEs in the non-OSA group (HR:3.34;95% CI:1.0–11.12; P = .05). The OSA patients with ICR had a 5.1 higher risk of MACCEs compared with the non-OSA with CR group, P = .007. The OSA patients with CR had a similar 1-year MACCEs as all the non-OSA patients (HR:1.10; 95% CI:0.515–2.349; P = 0.806).

Conclusions

ACS patients with OSA and ICR have a high rate of MACCEs at 1 year. In contrast, the prognosis of ACS patients with OSA but CR is favorable and similar to patients without OSA. Adequate level of revascularization is recommended to optimize clinical outcomes in ACS patients with OSA.

Trial registration

Clinicaltrials.gov identifier NCT03362385.

Clinical significance of obstructive sleep apnea in patients with acute coronary syndrome in relation to diabetes status

OBJECTIVE

The prognostic significance of obstructive sleep apnea (OSA) in patients with acute coronary syndrome (ACS) according to diabetes mellitus (DM) status remains unclear. We aimed to elucidate the association of OSA with subsequent cardiovascular events in patients with ACS with or without DM.

RESEARCH DESIGN AND METHODS

In this prospective cohort study, consecutive eligible patients with ACS underwent cardiorespiratory polygraphy between June 2015 and May 2017. OSA was defined as an Apnea Hypopnea Index ≥15 events/hour. The primary end point was major adverse cardiovascular and cerebrovascular events (MACCEs), including cardiovascular death, myocardial infarction, stroke, ischemia-driven revascularization, or hospitalization for unstable angina or heart failure.

RESULTS

Among 804 patients, 248 (30.8%) had DM and 403 (50.1%) had OSA. OSA was associated with 2.5 times the risk of 1 year MACCE in patients with DM (22.3% vs 7.1% in the non-OSA group; adjusted HR (HR)=2.49, 95% CI 1.16 to 5.35, p=0.019), but not in patients without DM (8.5% vs 7.7% in the non-OSA group, adjusted HR=0.94, 95% CI 0.51 to 1.75, p=0.85). Patients with DM without OSA had a similar 1 year MACCE rate as patients without DM. The increased risk of events was predominately isolated to patients with OSA with baseline glucose or hemoglobin A1c levels above the median. Combined OSA and longer hypoxia duration (time with arterial oxygen saturation <90%>22 min) further increased the MACCE rate to 31.0% in patients with DM.

CONCLUSIONS

OSA was associated with increased risk of 1 year MACCE following ACS in patients with DM, but not in non-DM patients. Further trials exploring the efficacy of OSA treatment in high-risk patients with ACS and DM are warranted.

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.

Non-circadian signals in the intensive care unit: Point prevalence morning, noon and night

BACKGROUND

Intensive care unit (ICU) sleep disturbance is severe and potentially related to abnormal light and sound exposure.

OBJECTIVES

To assess the prevalence of measures of light and sound disturbance in ICU patient rooms, and whether these could be modified by a sleep-promotion intervention.

METHODS

This observational study with a before and after design for a quality improvement initiative surveyed environmental factors in ICU rooms at 01:00 08:00, and 12:00. Surveys assessed light usage, television usage, window shade position, and room door/curtain position. Factors were compared before and after an ICU sleep-promotion intervention.

RESULTS

990 (pre-intervention) and 819 (post-intervention) occupied rooms were surveyed. Pre-intervention, the prevalence of night-time factors included: bright lights on (21%), television on (46%), and room door open (94%). Post-intervention, more rooms had all lights off at night (41% v 50%, p = 0.04), and fewer rooms had open door curtains (57% v 42%, p = 0.001) and window shades (78% v 62%, p = 0.002).

CONCLUSIONS

Disruptive environmental factors are common in the ICU. Some factors improve with sleep-promotion interventions.

Timely diagnosis and treatment of sleep apnea reduce cardiovascular sequelae in patients with myocardial infarction

Background

The present study aimed to test if the temporal sequence between sleep apnea (SA) diagnosis and incident myocardial infarction (MI) was associated with the long-term mortality and cardiovascular event in a community-based cohort.

Methods

We retrieved data from 9,453 incident MI patients between Jan. 1^st 2000 and Dec. 31^st 2012 from the Taiwan National Health Insurance Research Database. The study subjects included 207 MI patients with SA (SA-MI), further stratified into 110 with pre-existing SA before MI (SA-bMI) and 96 diagnosed with SA after MI (SA-pMI). The median follow-up period was 4.2 years. Propensity-score-matched controls were selected from 9,246 non-SA MI patients (non-SA-MI). The association of SA and outcomes including all-cause mortality and major adverse cardiac and cerebrovascular events (MACCEs) were analyzed by a Cox proportional hazards model.

Results

The result showed that SA was not associated with mortality regardless of the timing of SA diagnosis. SA-pMI was associated with increased risk of MACCEs (Hazard ratio [HR]: 1.412, 95% confidence interval [CI]: 1.037~1.923, p = 0.029) including re-MI or revascularization and ischemic heart disease hospitalization. Such an association was most significant for SA diagnosed within one year after MI (HR: 2.029, 95% CI: 1.265~3.254, p = 0.003), which was not seen in patients treated with continuous positive airway pressure (CPAP).

Conclusion

The temporal sequence and the time interval between SA diagnosis and incident MI was associated with the cardiovascular events after MI, especially within one year after MI. Early assessment for the presence of SA after incident MI and early CPAP intervention may reduce the risk of further adverse cardiovascular events.

Sleep Disturbance after Hospitalization and Critical Illness: A Systematic Review

RATIONALE

Sleep disturbance during intensive care unit (ICU) admission is common and severe. Sleep disturbance has been observed in survivors of critical illness even after transfer out of the ICU. Not only is sleep important to overall health and well being, but patients after critical illness are also in a physiologically vulnerable state. Understanding how sleep disturbance impacts recovery from critical illness after hospital discharge is therefore clinically meaningful.

OBJECTIVES

This Systematic Review aimed to summarize studies that identify the prevalence of and risk factors for sleep disturbance after hospital discharge for critical illness survivors.

DATA SOURCES

PubMed (January 4, 2017), MEDLINE (January 4, 2017), and EMBASE (February 1, 2017).

DATA EXTRACTION

Databases were searched for studies of critically ill adult patients after hospital discharge, with sleep disturbance measured as a primary outcome by standardized questionnaire or objective measurement tools. From each relevant study, we extracted prevalence and severity of sleep disturbance at each time point, objective sleep parameters (such as total sleep time, sleep efficiency, and arousal index), and risk factors for sleep disturbance.

SYNTHESIS

A total of 22 studies were identified, with assessment tools including subjective questionnaires, polysomnography, and actigraphy. Subjective questionnaire studies reveal a 50-66.7% (within 1 mo), 34-64.3% (>1-3 mo), 22-57% (>3-6 mo), and 10-61% (>6 mo) prevalence of abnormal sleep after hospital discharge after critical illness. Of the studies assessing multiple time points, four of five questionnaire studies and five of five polysomnography studies show improved aspects of sleep over time. Risk factors for poor sleep varied, but prehospital factors (chronic comorbidity, pre-existing sleep abnormality) and in-hospital factors (severity of acute illness, in-hospital sleep disturbance, pain medication use, and ICU acute stress symptoms) may play a role. Sleep disturbance was frequently associated with postdischarge psychological comorbidities and impaired quality of life.

CONCLUSIONS

Sleep disturbance is common in critically ill patients up to 12 months after hospital discharge. Both subjective and objective studies, however, suggest that sleep disturbance improves over time. More research is needed to understand and optimize sleep in recovery from critical illness.

Association of intensive care unit delirium with sleep disturbance and functional disability after critical illness: an observational cohort study

Background

In medical intensive care unit (MICU) patients, the predictors of post-discharge sleep disturbance and functional disability are poorly understood. ICU delirium is a risk factor with a plausible link to sleep disturbance and disability. This study evaluated the prevalence of self-reported post-ICU sleep disturbance and increased functional disability, and their association with MICU delirium and other ICU factors.

Methods

This was an observational cohort study of MICU patients enrolled in a biorepository and assessed upon MICU admission by demographics, comorbidities, and baseline characteristics. Delirium was assessed daily using the Confusion Assessment Method for the ICU. Telephone follow-up interview instruments occurred after hospital discharge and included the Pittsburgh Sleep Quality Index (PSQI), and basic and instrumental activities of daily living (BADLs, IADLs) for disability. We define sleep disturbance as a PSQI score > 5 and increased disability as an increase in composite BADL/IADL score at follow-up relative to baseline. Multivariable regression modeled the associations of delirium and other MICU factors on follow-up PSQI scores and change in disability scores.

Results

PSQI and BADL/IADL instruments were completed by 112 and 122 participants, respectively, at mean 147 days after hospital discharge. Of those surveyed, 63% had sleep disturbance by PSQI criteria, and 37% had increased disability by BADL/IADL scores compared to their pre-MICU baseline. Total days of MICU delirium (p = 0.013), younger age (p = 0.013), and preexisting depression (p = 0.025) were significantly associated with higher PSQI scores at follow-up. Lower baseline disability (p < 0.001), older age (p = 0.048), and less time to follow-up (p = 0.024) were significantly associated with worsening post-ICU disability, while the occurrence of MICU delirium showed a trend toward association (p = 0.077).

Conclusions

After adjusting for important covariates, total days of MICU delirium were significantly associated with increased post-discharge sleep disturbance. Delirium incidence showed a trend toward association with increased functional disability in the year following discharge.

Predictors of long-term adherence to continuous positive airway pressure in patients with obstructive sleep apnoea and acute coronary syndrome

Background

Continuous positive airway pressure (CPAP) is an effective treatment for obstructive sleep apnoea (OSA), but an evaluation of CPAP adherence is rarely carried out among patients with acute coronary syndrome (ACS). The goals of the study are to analyse long-term adherence and identify the predictors of non-compliance with CPAP treatment for patients with non-sleepy OSA and ACS.

Methods

This is an ancillary study of the ISAACC study, which is a multicentre, prospective, open-label, parallel, randomized, and controlled trial (NCT01335087) in patients with hospital admission for ACS. For the purpose of this study, only non-sleepy patients with moderate or severe OSA and randomized to receive CPAP treatment were analysed (n=357). Non-compliance was defined as CPAP dropout or average cumulative CPAP use of <4 hours/night. Multivariable logistic regression analysis was performed to identify predictors of CPAP adherence.

Results

Adherence to treatment was 35.3% at 12 months. According to the unadjusted analysis, higher apnoea-hypopnea index (AHI) (P<0.001) and oxygen desaturation index (ODI) (P=0.001) were associated with a lower risk of non-compliance. Multivariable logistic regression analysis showed that high AHI (P=0.0051), high amounts of smoking pack-year (P=0.0170), and long intensive care unit (ICU) stays (P=0.0263) were associated with lower odds of non-compliance. It also showed a significant interaction between ACS history and age (P=0.0131), such that young patients with their first ACS showed significantly lower odds of CPAP non-compliance than patients with recurrent ACS and significantly lower odds of CPAP non-compliance were associated with ageing only in patients with recurrent ACS.

Conclusions

Protective factors against non-compliance with CPAP treatment in non-sleepy patients with ACS were illness severity (high values of AHI or ICU stay length) or smoking amount. Patients with no previous history of ACS showed lower odds of CPAP non-compliance than patients with a recurrent ACS with younger age.

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.

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.

Awareness of obstructive sleep apnea-hypopnea syndrome among the general population of the Lorraine Region of France

OBJECTIVE

Obstructive sleep apnea-hypopnea syndrome (OSAHS) seems to be underdiagnosed. The aim of this study was to assess awareness of OSAHS among the general population of the Lorraine Region of France.

METHODS

A descriptive epidemiological study was carried out from July to November 2015 in the Lorraine Region, using an anonymous questionnaire that assessed knowledge of OSAHS-related symptoms and complications. The survey was also circulated on the Internet via social media. Exclusion criteria comprised age under 18 years, refusal to fill out the questionnaire and linguistic barrier.

RESULTS

1307 subjects filled out the survey: 1020 on paper format and 287 via the Internet. About two-thirds of the population recognized a majority of symptoms. However, there was a significant lack of knowledge of complications, especially cardiological and neurological. Suffering from OSAHS, having had higher education, and being under 40 years of age, were factors linked to better awareness of the syndrome. Internet respondents also showed better awareness.

CONCLUSION

Despite encouraging results regarding OSAHS symptoms, the general population showed limited awareness of its complications. Innovative educational campaigns must be organized to inform practitioners and the general public about the disease and raise awareness of its complications.

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.

The Accuracy of Portable Monitoring in Diagnosing Significant Sleep Disordered Breathing in Hospitalized Patients

BACKGROUND

Polysomnograms are not always feasible when sleep disordered breathing (SDB) is suspected in hospitalized patients. Portable monitoring is a practical alternative; however, it has not been recommended in patients with comorbidities.

OBJECTIVE

We evaluated the accuracy of portable monitoring in hospitalized patients suspected of having SDB.

DESIGN

Prospective observational study.

SETTING

Large, public, urban, teaching hospital in the United States.

PARTICIPANTS

Hospitalized patients suspected of having SDB.

METHODS

Patients underwent portable monitoring combined with actigraphy during the hospitalization and then polysomnography after discharge. We determined the accuracy of portable monitoring in predicting moderate to severe SDB and the agreement between the apnea hypopnea index measured by portable monitor (AHIPM) and by polysomnogram (AHIPSG).

RESULTS

Seventy-one symptomatic patients completed both tests. The median time between the two tests was 97 days (IQR 25-75: 24-109). Forty-five percent were hospitalized for cardiovascular disease. Mean age was 52±10 years, 41% were women, and the majority had symptoms of SDB. Based on AHIPSG, SDB was moderate in 9 patients and severe in 39. The area under the receiver operator characteristics curve for AHIPM was 0.8, and increased to 0.86 in patients without central sleep apnea; it was 0.88 in the 31 patients with hypercapnia. For predicting moderate to severe SDB, an AHIPM of 14 had a sensitivity of 90%, and an AHIPM of 36 had a specificity of 87%. The mean±SD difference between AHIPM and AHIPSG was 2±29 event/hr.

CONCLUSION

In hospitalized, symptomatic patients, portable monitoring is reasonably accurate in detecting moderate to severe SDB.

Effect of Obstructive Sleep Apnea in Acute Coronary Syndrome

The effect of obstructive sleep apnea (OSA) on clinical outcomes after acute coronary syndrome (ACS) is incompletely defined. We sought to determine the prevalence of OSA in patients with ACS and evaluate prognostic impact of OSA and continuous positive airway pressure (CPAP) therapy in these patients. This was a prospective longitudinal cohort study of 73 patients admitted on cardiac intensive care unit for ACS. Cardiorespiratory sleep study and/or polysomnography were performed in all patients. CPAP was recommended if Apnea-Hypopnea Index ≥5. The main study outcome was a composite of death for any cause, myocardial infarction, and myocardial revascularization. OSA was diagnosed in 46 patients (63%). Age and cardiovascular risk factors were not significantly different between groups. OSA was classified as mild (m-OSA) in 14 patients (30%) and as moderate-to-severe (s-OSA) in 32 patients (70%). After a median follow-up of 75 months (interquartile range 71 to 79), patients with s-OSA had lower event-free survival rate. After adjustment for gender, patients with s-OSA showed a significantly higher incidence of the composite end point (hazard ratio 3.58, 95% CI 1.09 to 17.73, p = 0.035). Adherence to CPAP occurred in 19 patients (41%), but compliance to CPAP therapy did not reduce the risk of composite end point (hazard ratio 0.87, 95% CI 0.31 to 2.46, p = 0.798). In conclusion, OSA is an underdiagnosed disease with high prevalence in patients with ACS. It is urgent to establish screening protocols because those have high diagnostic yield and allow identifying a group of patients with manifestly unfavorable prognosis.

Obstructive sleep apnea and acute coronary syndromes: etiology, risk, and management

Obstructive sleep apnea (OSA) is characterized by upper airway collapse and airflow reduction despite respiratory effort, resulting in intermittent hypoxia and arousals, leading to a cascade of hemodynamic, autonomic, inflammatory, and metabolic effects, responsible for its adverse cardiovascular effect. OSA is an independent risk factor for cardiovascular disease, and its prevalence in patients presenting with acute coronary syndromes is up to 69%. Furthermore, OSA has been associated with increased risk of adverse events after an acute coronary syndrome. Continuous positive airway pressure is considered the mainstay of treatment of OSA and has been shown to reduce the risk of cardiovascular events. However, the proper time to start treatment in the acute setting is unknown. A prospective randomized clinical trial is currently underway to answer this question.

Very early screening for sleep-disordered breathing in acute coronary syndrome in patients without acute heart failure

BACKGROUND

Obstructive sleep apnea (OSA) is frequently associated with acute coronary syndrome (ACS). Screening of sleep-disordered breathing (SDB) has not been previously evaluated in ACS within 72 h in intensive care settings and its management could potentially enhance patients' prognosis. This pilot study assessed the feasibility of SDB screening at the early phase of ACS.

METHODS

All consecutive patients admitted to the coronary care unit (CCU) for ACS without acute heart failure underwent one overnight-attended polysomnography (PSG) within 72 h after admission. A telemonitoring (TM) system was set up to remotely monitor the signals and repair faulty sensors. The 27 recordings were analyzed as respiratory polygraphy (RP) and as PSG, and the results were compared.

RESULTS

The TM system allowed successful intervention in 48% of recordings, resulting in excellent quality PSG for 89% of cases. The prevalence of SDB [apnea-hypopnea index (AHI) ≥ 15/h] was 82% and mainly consisted of central SDB and periodic breathing, except three patients with OSA. Compared with PSG, RP underestimated AHI, probably due to the poor sleep efficiency, reduction of slow-wave sleep, and alteration of rapid eye movement sleep.

CONCLUSION

An early SDB screening by remote-attended PSG is feasible in ACS patients shortly after admission to CCU. The TM enhanced the quality of PSG. A high prevalence of central SDB was noticed, for which the etiology remains unknown. Further large-scale studies are needed to determine whether central SDB is an incidental finding in early ACS and whether the presence and severity of SDB have a prognostic impact.

Prognostic implication of obstructive sleep apnea diagnosed by post-discharge sleep study in patients presenting with acute coronary syndrome

OBJECTIVE

We aimed to determine the prognostic implications of obstructive sleep apnea (OSA) diagnosed during the recovery phase of acute coronary syndrome (ACS).

METHODS

Patients presenting with ACS and treated with percutaneous coronary intervention were recruited prospectively for a home-based sleep study within 30 days of hospital discharge. Major adverse cardiac and cerebrovascular events (MACCEs) assessed included cardiac death, myocardial infarction, stroke, unplanned revascularization, and hospitalization for heart failure.

RESULTS

Of the 85 patients recruited, 68 successfully completed the study. The median time from percutaneous coronary intervention to sleep study was 14 days (interquartile range: 7.5-27 days). OSA was diagnosed in 24 patients (35.3%) (apnea-hypopnea index > or =15). A drug-eluting stent was implanted into the target lesion in 45 patients (66.2%). None of the study patients had received treatment for OSA. At 24-month follow-up, the MACCE incidence was 34.9% in the OSA group and 5.1% in the non-OSA group (P=0.008, log-rank test). After adjusting for the possible confounding effect of age, gender, coronary intervention indications, hypertension, smoking, and body mass index, OSA remained an independent predictor of MACCEs (adjusted hazard ratio, 6.95; 95% confidence interval, 1.17-41.4; P=0.033).

CONCLUSION

OSA diagnosed in patients treated with percutaneous coronary intervention for ACS by post-discharge sleep studies conducted 2 weeks after percutaneous coronary intervention was independently associated with MACCEs at 24-month follow-up.

[Cardiovascular morbidity associated with obstructive sleep apnea syndrome]

INTRODUCTION

The obstructive sleep apnoea syndrome (OSAS) had become a major public health concern in modern society due to its high prevalence but, above all, to its associated morbidity, especially cardiovascular.

BACKGROUND

Untreated OSAS is associated with an increased incidence of fatal (myocardial infarction and stroke) (odds ratio: 2.87) and non-fatal cardiovascular events (myocardial infarction, stroke, coronary artery bypass surgery and coronary angiography) (odds ratio: 3.17). Moreover, the prevalence of hypertension in patients with OSAS is high, between 35 and 80%. The pathophysiological mechanisms leading to these complications are mainly due to intermittent hypoxia secondary to repeated episodes of apnoea/hypopnoea during sleep. These mechanisms include sympathetic hyperactivation, impairment of vasomotor reactivity, vascular inflammation, oxidative stress and metabolic disorders. In patients with OSAS, the impact of continuous positive pressure is proven in terms of prevention of cardiovascular events although blood pressure reduction is limited. Obviously these effects are proportional to observance.

CONCLUSION

OSAS does increase the cardiovascular risk, independently of other risk factors. Although the impact of treatment is relatively low in decreasing blood pressure, it seems essentially effective in preventing cardiovascular morbidity. Therefore, OSAS screening, and the association of specific treatments in cardio-metabolic patients and OSAS patients respectively, should be included in clinical strategies.

Excessive daytime sleepiness is associated with longer culprit lesion and adverse outcomes in patients with coronary artery disease

STUDY OBJECTIVES

We assessed whether excessive daytime sleepiness was associated with coronary plaque phenotype and subsequent adverse cardiovascular events.

METHODS

Prospective cohort study. Intravascular ultrasound (IVUS) examination of the culprit coronary stenosis was performed. The Epworth Sleepiness Scale (ESS) questionnaire was administered, and the patients were divided into 2 groups-(1) sleepier and (2) less sleepy-based on the ESS score. Adverse cardiovascular outcomes were defined as cardiac death, myocardial infarction, stroke, unplanned revascularization, or heart failure admission.

RESULTS

One hundred seventeen patients undergoing urgent or non-urgent coronary angiography were recruited. Compared with the less sleepy group (ESS ≤ 10, n = 87), the sleepier group (ESS > 10, n = 30) had higher serum levels of total cholesterol and of low-density-lipoprotein cholesterols (p < 0.05 for both). The IVUS examinations indicated coronary stenoses were longer in the sleepier group than in the less sleepy group (p = 0.011). The cumulative incidence of adverse cardiovascular events at 16-month follow-up was higher in the sleepier than the less sleepy group (12.5% versus 6.9%, p = 0.03). Cox regression analysis adjusting for age and smoking showed increased hazard of adverse cardiovascular events in sleepier group as compared to less sleepy group (HR = 3.44, 95% CI 1.01-11.72).

CONCLUSION

In patients presenting with coronary artery disease, excessive daytime sleepiness based on ESS > 10 was associated with longer culprit lesions and future adverse cardiovascular events.

Clinical correlates of insomnia in patients with acute coronary syndrome

This study sought to examine the prevalence of insomnia and its association with depression, anxiety, and medical comorbidities in patients after an acute coronary syndrome (ACS). Insomnia increases risk of recurrent cardiac events in ACS patients, but little is known about the prevalence and clinical correlates of insomnia in this setting. Patients (n = 102, 58.3 ± 10.6 years-old) admitted for ACS to a cardiology service at an urban academic medical center completed the Insomnia Severity Index, Epworth Sleepiness Scale, and measures of depression and anxiety. A subset (n = 20) completed ambulatory polysomnography (PSG) in their homes several weeks after discharge. Moderate or severe insomnia was reported by 37% of patients during hospitalization and was associated with 76 minutes more wake after sleep onset measured by home PSG. Although depression and insomnia were strongly associated, about 1 in 4 patients with insomnia did not report significant depressive symptoms. Sleep apnea was documented in 80% of patients on PSG, but insomnia was not associated with sleep apnea, periodic limb movements, demographic factors, or medical conditions other than liver disease. Insomnia is present in over one-third of ACS patients during hospitalization, but at-risk patients could not be readily identified by demographic or medical factors or by depression symptoms.

Prevalence and risk factors of sleep disordered breathing in patients with rheumatic valvular heart disease

STUDY OBJECTIVES

Sleep disordered breathing (SDB) is common in patients with chronic heart failure secondary to non-valvular heart disease; however, the prevalence and characteristics of SDB in patients with rheumatic valvular heart disease (RVHD) are unclear. This study was designed to determine the prevalence, characteristics, and risk factors for SDB in RVHD patients.

METHODS

A cross-sectional study was conducted in 260 RVHD patients. The following data were recorded: types of heart valve lesions, electrocardiographic, echocardiographic, arterial blood gas analysis findings, baseline medication, 6-minute walk test (6MWT) distance, and sleep parameters.

RESULTS

Compared to patients with single leftsided valve lesions, patients with left- and rightsided valve lesions had a higher prevalence of SDB (46.2% vs. 31.2%, p = 0.013); the increased prevalence of SDB only involved central sleep apnea (CSA) (31.1% vs. 14.1%, p = 0.001). Patients with obstructive sleep apnea (OSA) or CSA were older and had a shorter 6MWT distance, lower left ventricle ejection fraction and PaO₂, a longer lung-to-finger circulation time, and a higher prevalence of atrial fibrillation (AF) and hypertension (all p < 0.05) as compared with patients without SDB. Multinomial logistic regression analysis showed that PaO2 ≤ 85 mm Hg was the only risk factor for OSA. Male gender, AF, 6MWT distance ≤ 300 m, PaO₂ ≤ 85 mmHg, and PaCO₂ ≤ 40 mm Hg were risk factors for CSA.

CONCLUSIONS

Patients with RVHD had a high prevalence of SDB (predominantly CSA). RVHD patients with SDB, particularly those who had CSA, manifested more severe symptoms and greater impairment of cardiac function. Assessments of clinical manifestations of cardiac dysfunction may be important for predicting the risk factors for SDB.

Rationale and methodology of the impact of continuous positive airway pressure on patients with ACS and nonsleepy OSA: the ISAACC Trial

BACKGROUND

Obstructive sleep apnea (OSA) is common in acute coronary syndrome (ACS) and a possible cause of increased morbidity and mortality.

OBJECTIVES

The main objective is to determine in patients with ACS and OSA if CPAP treatment reduces the incidence of cardiovascular events (cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, hospitalization for heart failure, and hospitalization for unstable angina or transient ischemic attack). The secondary objectives are to determine the prevalence of nonsleepy OSA in patients with ACS; assess the effect of CPAP on the incidence of newly diagnosed diabetes mellitus, symptoms, and quality of life; identify biomarkers of risk involved in cardiovascular complications in these patients; and conduct a cost-effectiveness analysis of diagnosis and treatment.

POPULATION AND METHODOLOGY

Multicenter, prospective, randomized and controlled study. Patients are admitted to the coronary care unit with diagnosis of ACS and without daytime sleepiness (Epworth Sleepiness Scale ≤10) at 15 teaching hospitals in Spain. All patients undergo a sleep study by cardiorespiratory polygraphy. Patients with an apnea-hypopnea index ≥15/hour will be randomized to treatment with CPAP (group 1, 632 patients) or conservative treatment (group 2, 632 patients). Patients with an apnea-hypopnea index <15/hour (group 3, 600 patients) will be followed as a reference group. Patients will be monitored at baseline (T0), 1 month (T1), 3 months (T2), 6 months (T3), 12 months (T4), and every 6 months thereafter (where applicable) during the follow-up period.

CONCLUSIONS

The ISAACC trial will contribute to evaluating the effect of CPAP treatment on cardiovascular events in patients with ACS and OSA.