Prevalence, Impact, and Trajectories of Sleep Disturbance in Cardiac Rehabilitation: A NARRATIVE REVIEW AND SUGGESTIONS FOR EVALUATION AND TREATMENT

OBJECTIVE

The aim of this review was to summarize literature examining the prevalence, impact, and trajectories of sleep disturbance in cardiac rehabilitation (CR) patients and discuss how CR programs may incorporate targeted evaluation and interventions to promote sleep health.

REVIEW METHODS

A narrative review of literature allowed for an examination of the prevalence of sleep disturbance in CR patients, the effects of sleep disturbance on CR outcomes, and trajectories of sleep disturbance in CR.

SUMMARY

Sleep disturbance is prevalent in CR patient populations and is related to clinical and functional outcomes. Sleep may be an important biobehavioral process to target in CR to improve important patient outcomes and achieve secondary prevention goals.

Does an undetected obstructive sleep apnea influence the natural course and success of cardiac rehabilitation after cardiac surgery?

BACKGROUND

Obstructive Sleep Apnea (OSA) is common in patients with cardiovascular diseases (CVD) and can negatively impact the course of CVD. However, scarce data are available for patients before or after cardiac surgery (CS) in the context of OSA.

AIM

This study investigated the impact of an undetected OSA on the results of cardiac rehabilitation (CR) in patients after CS.

DESIGN

Observational study over a period of 3 months following CS.

SETTING

The setting of this study was inpatient CR after CS or cardiac interventions.

POPULATION

CS cohort referred to a CR program to an inpatient rehabilitation clinic in Switzerland.

METHODS

In this prospective observational study 256 patients were screened for OSA at the entry of CR via a level III screening device (ApneaLink Air^TM, Resmed, San Diego, CA, USA). They were stratified into two groups: apnea hypopnea index (AHI) >15 or <15/h. A comprehensive assessment was performed at entry and end of CR including six-minute walk test (6-MWT), Functional Independence Measure (FIM), Hospital Anxiety and Depression Scale, MacNewHeart (MNH), STOP-Bang Questionnaire (SBQ) and Epworth Sleepiness Scale (ESS).All patients participated in a comprehensive CR program with a mean duration of approximately 3 weeks. Another OSA screening was performed at the end of the PR program and after 3 months in order to observe the clinical course of OSA.

RESULTS

An AHI>15/h was found in 133 patients (59%) at baseline, 54% after 3 weeks and 43% after 3 months. The AHI>15/h-group was older, had a higher BMI, more frequent hypertension and coronary artery disease, and higher ESS and SBQ scores compared to the AHI<15/h-group. The results of the STOP-Bang and ESS questionnaires showed a statistically significant but weak positive correlation with AHI. However, in both groups ESS did not improve from baseline to the end of CR. A multivariable logistic regression model confirmed age and ESS as independent positive predictors of OSA. No differences were found between both groups according to the results of the 6-MWT, HADS and MNH.

CONCLUSIONS

OSA had a high prevalence in a large CS cohort referred to CR. However, moderate-severe OSA, though symptomatic, had no significant influence on the outcome during CR and on the parameters representing success.

CLINICAL REHABILITATION IMPACT

In our study the improvements during CR after CS were not influenced by the presence of significant OSA which is remarkable since the presence of OSA is thought to be associated with increased rates of cardiovascular adverse events after cardiovascular intervention or CS. This is true at least for the success of CR after CS. The long-term consequences of untreated OSA in CVD remain unclear and are still the subject of current research.

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.

Upper airway stabilization by osteopathic manipulation of the sphenopalatine ganglion versus sham manipulation in OSAS patients: a proof-of-concept, randomized, crossover, double-blind, controlled study

Background

Osteopathic manipulative treatment (OMT) of the sphenopalatine ganglion (SPG) is used empirically for the treatment of rhinitis and snoring and is thought to increase pharyngeal stability. This trial was designed to study the effects of this treatment on pharyngeal stability evaluated by critical closing pressure in obstructive sleep apnoea syndrome.

Methods

This single-centre, randomized, crossover, double-blind study compared active manipulation and sham manipulation of the SPG. Randomization was computer-generated. Patients each received one active manipulation and one sham manipulation at an interval of 21 days and were evaluated 30 min and 48 h after each session administered by a qualified osteopath. Neither the patients, nor the investigator performing the evaluations were informed about the order of the two techniques (double-blind). The primary endpoint was the percentage of responding patients presenting increased pharyngeal stability defined by a variation of critical closing pressure (Pcrit) of at least −4 cmH₂O at 30 min. Secondary endpoints were the variation of Pcrit in absolute values, sleepiness and snoring. Others endpoints were lacrimation (Schirmer’s test), induced pain, sensations experienced during OMT.

Results

Ten patients were included and nine (57 [50; 58] years, comprising 7 men, with an apnoea-hypopnoea index of 31.0 [25.5; 33.2]/h; (values are median [quartiles])) were analysed. Seven patients were analysed for the primary endpoint and nine patients were analysed for secondary endpoints. Five patients responded after active manipulation versus no patients after sham manipulation (p = 0.0209). Active manipulation induced more intense pain (p = 0.0089), increased lacrimation (ns) and more tactile, nociceptive and gustatory sensations (13 versus 1) compared to sham manipulation. No significant difference was observed for the other endpoints.

Conclusions

Osteopathic manipulative treatment of the SPG may improve pharyngeal stability in obstructive sleep apnoea syndrome. This trial validates the feasibility of the randomized, controlled, double-blind methodology for evaluation of this osteopathic treatment. Studies on a larger sample size must specify the efficacy on the apnoea-hypopnoea index.

Trial registration

The study was retrospectively registered in the clinicaltrial.gov registry under reference NCT01193738 on 1st September 2010 (first inclusion May 19, 2010).

Electronic supplementary material

The online version of this article (doi: 10.1186/s12906-017-2053-0) contains supplementary material, which is available to authorized users.

Prevalence of Sleep-Disordered Breathing and Patient Characteristics in a Coronary Artery Disease Cohort Undergoing Cardiovascular Rehabilitation

PURPOSE

Coronary artery disease (CAD) is a leading cause of death and identification of risk factors for CAD is crucial. One such potential risk factor is sleep-disordered breathing (SDB). This prospective cohort study investigated the prevalence of SDB and determined risk factors for the presence of SDB in a large CAD cohort undergoing cardiac rehabilitation.

METHODS

A total of 1425 patients with confirmed CAD starting rehabilitation were screened for SDB using cardiorespiratory polygraphy (n = 921) or polygraphy plus pulse oximetry (n = 484).

RESULTS

A total of 1408 patients were included; 69.5% were male, 78% had acute coronary syndrome, and 22% had stable CAD. The prevalence of SDB (apnea-hypopnea index [AHI] ≥5/h) was 83%. Moderate to severe SDB (AHI ≥15/h) was present in 53%. Up to 70% of coronary artery bypass graft (CABG) recipients had an AHI ≥15/h versus 33% of those who had not undergone CABG. SDB severity did not vary significantly in patients with stable CAD or on the basis of left ventricular ejection fraction. SDB was more severe and the frequency of oxygen desaturation was higher in men than in women. Multivariate logistic regression identified age, sex, body mass index, and CABG as independent risk factors for severe SDB.

CONCLUSION

SDB is a highly prevalent comorbidity in patients with CAD, particularly those who have undergone CABG. These results strengthen existing associations and emphasize the importance of diagnosing and monitoring SDB in patients with CAD entering a cardiac rehabilitation program. Early diagnosis and intervention has the potential to have a beneficial effect on CAD prognosis.

Prevalence and predictors of sleep apnea in patients with stable coronary artery disease: a cross-sectional study

BACKGROUND

Sleep apnea (SA) is increasingly recognized as being important in the prognosis of patients with coronary artery disease (CAD); however, symptoms of SA are not easily identified, and as many as 80% of sufferers remain undiagnosed.

AIM

This cross-sectional study investigated the prevalence and predictors of SA that may help to increase the awareness and diagnosis of SA in stable CAD patients.

MATERIALS AND METHODS

Polysomnography was performed in 772 medically stable CAD patients with untreated SA recruited from the Clinic of Cardiovascular Rehabilitation. Patients were predominantly male (76%), median age was 58 years (32-81). All subjects completed the Epworth sleepiness scale (ESS). The frequency of all apneas and hypopneas associated with 3% oxygen desaturation is referred to as the apnea-hypopnea index (AHI). Mild-to-severe SA was defined as AHI ≥5/h, moderate-to-severe SA as AHI ≥15/h.

RESULTS

AHI was within a range of values that was considered normal or only mildly elevated. The median AHI was 3.4 (interquartile range [IQR 1-9]), and 39% of patients had unrecognized mild-to-severe SA (moderate-to-severe in 14%), which was not higher than other known risk indicators for CAD such as hypertension and obesity (83% and 47%, respectively). These patients did not show sleepiness and the risk-related cut-off score for excessive daily sleepiness was lower than the official for ESS.

CONCLUSION

Hypertension, age, male gender, obesity, ESS ≥6, and left ventricular ejection fraction ≤45% were the best predictors of mild-to-severe SA. While, male gender, age 50-70 years and, mainly, the presence of obesity but not hypertension were clinical predictors for moderate-to-severe SA. In addition, association between mild-to-severe SA and obesity was not evident in women. SA is prevalent comorbidity in the stable CAD patients, especially in its asymptomatic mild form. We suggest that SA should be considered in the secondary prevention protocols for CAD.