Effect of continuous positive airway pressure on ventricular ectopy in heart failure patients with obstructive sleep apnoea

Sleep apnea, the risk of out-of-hospital cardiac arrest, and potential benefits of continuous positive airway pressure therapy: A nationwide study

OBJECTIVE

Patients with sleep apnea (SA) are at increased cardiovascular risk. However, little is known about the risk of out-of-hospital cardiac arrest (OHCA) in patients with SA. Therefore, we studied the relation between SA patients who did and did not receive continuous positive airway pressure (CPAP) therapy with OHCA in the general population.

METHODS

Using nationwide databases, we conducted a nested case-control study with OHCA-cases of presumed cardiac causes and age/sex/OHCA-date matched non-OHCA-controls from the general population. Conditional logistic regression models with adjustments for well-known OHCA risk factors were performed to generate odds ratio (OR) of OHCA comparing patients with SA receiving and not receiving CPAP therapy with individuals without SA.

RESULTS

We identified 46,578 OHCA-cases and 232,890 matched non-OHCA-controls [mean: 71 years, 68.8% men]. Compared to subjects without SA, having SA without CPAP therapy was associated with increased odds of OHCA after controlling for relevant confounders (OR:1.20, 95%-Cl:1.06-1.36), while having SA with CPAP therapy was not associated with OHCA (OR:1.04, 95%-Cl:0.93-1.36). Regardless of CPAP therapy, age and sex did not significantly influence our findings. Our findings were confirmed in: (I) patients with neither ischemic heart disease nor heart failure (untreated SA, OR:1.24, 95%-CI:1.04-1.47; SA with CPAP, OR:1.08, 95%-CI:0.93-1.25); and (II) in patients without cardiovascular disease (untreated SA, OR:1.33, 95%-CI:1.07-1.65; SA with CPAP, OR:1.14, 95%-CI:0.94-1.39).

CONCLUSION

SA not treated with CPAP was associated with OHCA, while no increased risk of OHCA was found for SA patients treated with CPAP.

Cardiac autonomic dysfunction and structural remodeling: the potential mechanism to mediate the relationship between obstructive sleep apnea and cardiac arrhythmias

Background

Cardiac arrhythmias are very common in patients with obstructive sleep apnea (OSA), especially atrial fibrillation (AF) and nonsustained ventricular tachycardia (NVST). Cardiac autonomic dysfunction and structural remodeling caused by OSA provide the milieu for cardiac arrhythmia development. This study aimed to determine whether OSA is associated with various cardiac arrhythmias and investigate potential pathophysiologic pathways between them.

Methods

The analysis covered 600 patients with clinical suspicion of OSA hospitalized in Renmin Hospital of Wuhan University between January 2020 and May 2023. After undergoing sleep apnea monitor, all subjects received laboratory tests, Holter electrocardiography, and Echocardiography.

Results

Compared with those without OSA and adjusting for potential confounders, subjects with moderate OSA had three times the odds of AF (odds ratio [OR] 3.055; 95% confidence interval [CI], 1.002-9.316; p = 0.048). Subjects with severe OSA had three times the odds of AF (OR 3.881; 95% CI, 1.306-11.534; p = 0.015) and NSVT (OR 3.690; 95% CI, 0.809-16.036; p = 0.046). There were significant linear trends for the association between OSA severity with AF and NVST (p < 0.05). And this association was mediated by cardiac structural changes including left atrial diameter, left ventricular diastolic diameter, right atrial diameter and right ventricular diameter. In addition, the ratio of low-frequency and high-frequency individually mediated the association between severe OSA and NVST.

Conclusion

This study demonstrated that severe OSA was independently associated with AF and NSVT, and this association was mediated by autonomic nervous system changes and cardiac structural remodeling.

Association between Obstructive Sleep Apnea and Heart Failure in Adults-A Systematic Review

BACKGROUND

Heart failure (HF) patients commonly experience obstructive sleep apnea (OSA), which may worsen their condition. We reviewed a diverse range of studies to investigate the prevalence of OSA in HF patients, the effects of positive airway pressure (PAP) treatment, and the potential impact of sodium-glucose cotransporter-2 inhibitors (SGLT2i) and sacubitril/valsartan on OSA outcomes.

METHODS

We analyzed case-control, observational studies, and randomized controlled trials. Prevalence rates, PAP treatment, and HF pharmacotherapy were assessed.

RESULTS

Numerous studies revealed a high prevalence of OSA in HF patients, particularly with preserved ejection fraction. PAP treatment consistently improved an apnea-hypopnea index, left ventricular ejection fraction, oxygen saturation, and overall quality of life. Emerging evidence suggests that SGLT2i and sacubitril/valsartan might influence OSA outcomes through weight loss, improved metabolic profiles, and potential direct effects on upper airway muscles.

CONCLUSIONS

The complex interplay between OSA and HF necessitates a multifaceted approach. PAP treatment has shown promising results in improving OSA symptoms and HF parameters. Additionally, recent investigations into the effects of HF pharmacotherapy on OSA suggest their potential as adjunctive therapy. This review provides insights for clinicians and researchers, highlighting the importance of addressing OSA and HF in patient management strategies.

International Consensus Statement on Obstructive Sleep Apnea

BACKGROUND

Evaluation and interpretation of the literature on obstructive sleep apnea (OSA) allows for consolidation and determination of the key factors important for clinical management of the adult OSA patient. Toward this goal, an international collaborative of multidisciplinary experts in sleep apnea evaluation and treatment have produced the International Consensus statement on Obstructive Sleep Apnea (ICS:OSA).

METHODS

Using previously defined methodology, focal topics in OSA were assigned as literature review (LR), evidence-based review (EBR), or evidence-based review with recommendations (EBR-R) formats. Each topic incorporated the available and relevant evidence which was summarized and graded on study quality. Each topic and section underwent iterative review and the ICS:OSA was created and reviewed by all authors for consensus.

RESULTS

The ICS:OSA addresses OSA syndrome definitions, pathophysiology, epidemiology, risk factors for disease, screening methods, diagnostic testing types, multiple treatment modalities, and effects of OSA treatment on multiple OSA-associated comorbidities. Specific focus on outcomes with positive airway pressure (PAP) and surgical treatments were evaluated.

CONCLUSION

This review of the literature consolidates the available knowledge and identifies the limitations of the current evidence on OSA. This effort aims to create a resource for OSA evidence-based practice and identify future research needs. Knowledge gaps and research opportunities include improving the metrics of OSA disease, determining the optimal OSA screening paradigms, developing strategies for PAP adherence and longitudinal care, enhancing selection of PAP alternatives and surgery, understanding health risk outcomes, and translating evidence into individualized approaches to therapy.

The effect of CPAP therapy on heart rate variability in patients with obstructive sleep apnea

The aim of this study was to analyze the relationship between the initiation of CPAP therapy and HRV in patients with OSA. The study group consisted of 37 patients, aged 34-79 (mean 54.95 years) with OSA treated with CPAP. Two subgroups of patients were distinguished: less than severe (AHI < 30, n = 16) and severe OSA (AHI ≥ 30, n = 21). The second study was carried out around a month after the initiation of therapy. CPAP therapy caused the improvement in polysomnographic parameters, however, in most parameters in time and frequency analysis, there were no significant positive changes in parasympathetic tone. Moreover, in HRV time analysis, the reduced rMSSD and pNN50 parameters in the hours of night rest and rMSSD and SDSD during the 15-min N3 sleep period were noted. Especially, in the group with AHI ≥ 30, we observed significant decreases in rMSSD and pNN50 for the entire time. The changes were mainly for the night periods including the N3 sleep period, which is especially connected with sleep apnea (parameters: rMSSD, SDSD, and pNN50). In spectral analysis, the decrease in HF from the 15-min daily activity period and the N3 sleep period was observed. Inverse correlations were seen between the maximum, median, and mean positive airway pressure (PAP) and the change in rMSSD, SDNN, and SDSD, mainly during night hours and the N3 sleep period. Only in patients with AHI < 30 the increase in SDNN was observed in 15-min N3 sleep period. The beneficial increase in SDNN parameter from time analysis was observed only in one sleep period in less ill patients with OSA. The lack of significant changes was observed in the majority of the parameters of heart rate variability after initiation of CPAP therapy in a short observational time; however, the shift towards reduced HRV was observed in patients with AHI > 30, so the response to CPAP therapy may depends on the severity of the apnea. The results may suggest that a longer observational period is needed in such studies, and the problem is still not fully elucidated.

A State-of-the-Art Review on Sleep Apnea Syndrome and Heart Failure

Heart failure (HF) affects many patients worldwide every year. It represents a leading cause of hospitalization and still, today, mortality remains high, albeit the progress in treatment strategies. Several factors contribute to the development and progression of HF. Among these, sleep apnea syndrome represents a common but still underestimated factor because its prevalence is substantially higher in patients with HF than in the general population and is related to a worse prognosis. This review summarizes the current knowledge about sleep apnea syndrome coexisting with HF in terms of morbidity and mortality to provide actual and future perspectives about the diagnosis, evaluation, and treatment of this association.

Sleep Arousal-Related Ventricular Repolarization Lability Is Associated With Cardiovascular Mortality in Older Community-Dwelling Men

BACKGROUND

Sleep is fragmented by brief arousals, and excessive arousal burden has been linked to increased cardiovascular (CV) risk, but mechanisms are poorly understood.

RESEARCH QUESTION

Do arousals trigger cardiac ventricular repolarization lability that may predispose people to long-term cardiovascular mortality?

STUDY DESIGN AND METHODS

This study analyzed 407,541 arousals in the overnight polysomnograms of 2,558 older men in the Osteoporotic Fractures in Men sleep study. QT and RR intervals were measured beat-to-beat starting 15 s prior to arousal onset until 15 s past onset. Ventricular repolarization lability was quantified by using the QT variability index (QTVi).

RESULTS

During 10.1 ± 2.5 years of follow-up, 1,000 men died of any cause, including 348 CV deaths. During arousals, QT and RR variability increased on average by 5 and 55 ms, respectively, resulting in a paradoxical transient decrease in QTVi from 0.07 ± 1.68 to -1.00 ± 1.68. Multivariable Cox proportional hazards analysis adjusted for age, BMI, cardiovascular and respiratory risk factors, sleep-disordered breathing and arousal, diabetes, and Parkinson disease indicated that excessive QTVi during arousal was independently associated with all-cause and CV mortality (all-cause hazard ratio, 1.20 [95% CI, 1.04-1.38; P = .012]; CV hazard ratio, 1.29 [95% CI, 1.01 -1.65; P = .043]).

INTERPRETATION

Arousals affect ventricular repolarization. A disproportionate increase in QT variability during arousal is associated with an increased all-cause and CV mortality and may reflect ventricular repolarization maladaptation to the arousal stimulus. Whether arousal-related QTVi can be used for more tailored risk stratification warrants further study, including evaluating whether arousal suppression attenuates ventricular repolarization lability and reduces subsequent mortality.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov; No.: NCT00070681; URL: www.

CLINICALTRIALS

gov.

Positive airway pressure therapy in heart failure patients comorbid with obstructive sleep apnea: Cardiovascular outcomes and nighttime-duration effect

BACKGROUND

Comorbidity of obstructive sleep apnea (OSA) and heart failure (HF) is becoming increasingly common. This is a global analysis of positive airway pressure (PAP) efficacy for the cardiovascular outcomes in those HF Patients with comorbid OSA.

METHODS

Related randomized controlled trials were included. Analysed indicators covered primary outcomes (cardiac function, motor ability and life quality) and secondary outcomes (blood pressure and OSA-accompanying symptoms). Weighted mean difference was used to analyse the PAP-control difference in different experimental phases and the baseline-post difference in different groups.

RESULTS

Compared with control group, PAP was associated with a 3.48% increase in left ventricle ejection fraction (LVEF) (p < .00001) and little decrease in heart rate (HR) (p = .67). Over 6 h of mean nighttime use was associated with a greater increase in LVEF of 5.21% (p = .0002) and a significant reduction in HR of 3.81 bpm (p = .03). There was no significant difference between PAP and control group in their association with change in motor ability and life quality. Besides, PAP was associated with a 13.08 mm Hg decrease in systolic blood pressure and great improvements in OSA-accompanying symptoms: Apnea-Hypopnea Index, -23.73 e/h; mean oxygen saturation, 1.86%; minimum oxygen saturation, 8.78%; Epworth Sleepiness Scale, -1.39 point; arousal index, -16.41 e/h. There was also no significant difference in diastolic blood pressure.

CONCLUSIONS

Positive airway pressure treatment improves cardiac function in HF patients with comorbid OSA, but the improved magnitude is associated with the duration of nighttime use rather than the duration of treatment.

Sleep-Disordered Breathing and Cardiac Arrhythmias in Adults: Mechanistic Insights and Clinical Implications: A Scientific Statement From the American Heart Association

Sleep-disordered breathing (SDB), characterized by specific underlying physiological mechanisms, comprises obstructive and central pathophysiology, affects nearly 1 billion individuals worldwide, and is associated with excessive cardiopulmonary morbidity. Strong evidence implicates SDB in cardiac arrhythmogenesis. Immediate consequences of SDB include autonomic nervous system fluctuations, recurrent hypoxia, alterations in carbon dioxide/acid-base status, disrupted sleep architecture, and accompanying increases in negative intrathoracic pressures directly affecting cardiac function. Day-night patterning and circadian biology of SDB-induced pathophysiological sequelae collectively influence the structural and electrophysiological cardiac substrate, thereby creating an ideal milieu for arrhythmogenic propensity. Cohort studies support strong associations of SDB and cardiac arrhythmia, with evidence that discrete respiratory events trigger atrial and ventricular arrhythmic events. Observational studies suggest that SDB treatment reduces atrial fibrillation recurrence after rhythm control interventions. However, high-level evidence from clinical trials that supports a role for SDB intervention on rhythm control is not available. The goals of this scientific statement are to increase knowledge and awareness of the existing science relating SDB to cardiac arrhythmias (atrial fibrillation, ventricular tachyarrhythmias, sudden cardiac death, and bradyarrhythmias), synthesizing data relevant for clinical practice and identifying current knowledge gaps, presenting best practice consensus statements, and prioritizing future scientific directions. Key opportunities identified that are specific to cardiac arrhythmia include optimizing SDB screening, characterizing SDB predictive metrics and underlying pathophysiology, elucidating sex-specific and background-related influences in SDB, assessing the role of mobile health innovations, and prioritizing the conduct of rigorous and adequately powered clinical trials.

Impact of Sleep-Disordered Breathing Treatment on Ventricular Tachycardia in Patients with Heart Failure

Background: Sleep-disordered breathing (SDB) is a highly common comorbidity in patients with heart failure (HF), and a known risk factor for ventricular tachycardia (VT) development. However, little is known about the impact of SDB treatment on VT burden in HF patients to date. Therefore, this study investigated VT burden, as well as implantable cardioverter-defibrillator (ICD) therapies in HF patients with SDB treatment, in comparison to untreated SDB HF patients. Methods: This retrospective study analyzed VT burden, rate of antitachycardia pacing (ATP), and the number of shocks delivered in a propensity score-matched patient cohort of patients with SDB treatment or control. Patients had moderate or severe SDB (n = 73 per each group; standardized mean difference of 0.08) and were followed for a minimum of one year. In addition, survival over 4 years was assessed. Results: Mean patient age was 67.67 ± 10.78 and 67.2 ± 10.10, respectively, with 15.06% and 10.95% of the patients, respectively, being female. Regarding SDB subtypes in the control and SDB treatment group, central sleep apnea was present in 42.46% and 41.09% of the patients, respectively, and obstructive sleep apnea was present in 26.02% and 31.50% of the patients, respectively. Mixed type sleep disorder was present in 31.50% and 27.40% of cases. Among the SDB treatment group, a significantly lower number of VTs (28.8% vs. 68.5%; p = 0.01), ATP (21.9% vs. 50.7%; p = 0.02), as well as a lower shock rate (5.5% vs. 31.5%; p < 0.01), was observed compared to the control group. Furthermore, the VT burden was significantly lower in the SDB treatment group when compared to the time prior to SDB treatment (p = 0.02). Event-free survival was significantly higher in the SDB treatment group (Log-rank p < 0.01). Conclusion: SDB treatment in HF patients with ICD leads to significant improvements in VT burden, ATP and shock therapy, and may even affect survival. Thus, HF patients should be generously screened for SDB and treated appropriately.

Methodology for the nocturnal cardiac arrhythmia ancillary study of the ADVENT-HF trial in patients with heart failure with reduced ejection fraction and sleep-disordered breathing

•

Sound methodology is necessary to identify arrhythmias from one-lead ECG during PSG.

•

Classification of arrhythmias from such an ECG is feasible.

•

Excellent inter-observer agreement on premature ventricular and atrial complexes.

•

These established methods allow analysing all ECGs from PSG of the ADVENT-HF trial.

Background

Sleep disordered breathing (SDB) may trigger nocturnal cardiac arrhythmias (NCA) in patients with heart failure with reduced ejection fraction (HFrEF). The NCA ancillary study of the ADVENT-HF trial will test whether, in HFrEF-patients with SDB, peak-flow-triggered adaptive servo-ventilation (ASVpf) reduces NCA. To this end, accurate scoring of NCA from polysomnography (PSG) is required.

Objective

To develop a method to detect NCA accurately from a single-lead electrocardiogram (ECG) recorded during PSG and assess inter-observer agreement for NCA detection.

Methods

Quality assurance of ECG analysis included training of the investigators, development of standardized technical quality, guideline-conforming semi-automated NCA-scoring via Holter-ECG software and implementation of an arrhythmia adjudication committee. To assess inter-observer agreement, the ECG was analysed by two independent investigators and compared for agreement on premature ventricular complexes (PVC) /h, premature atrial complexes/h (PAC) as well as for other NCA in 62 patients from two centers of the ADVENT-HF trial.

Results

The intraclass correlation coefficients for PVC/h and PAC/h were excellent: 0.99 (95%- confidence interval [CI]: 0.99–0.99) and 0.99 (95%-CI: 0.97–0.99), respectively. No clinically relevant difference in inter-observer classification of other NCA was found. The detection of non-sustained ventricular tachycardia (18% versus 19%) and atrial fibrillation (10% versus 11%) was similar between the two investigators. No sustained ventricular tachycardia was detected.

Conclusion

These findings indicate that our methods are very reliable for scoring NCAs and are adequate to apply for the entire PSG data set of the ADVENT-HF trial.

Effects of Adaptive Servo-Ventilation on Nocturnal Ventricular Arrhythmia in Heart Failure Patients With Reduced Ejection Fraction and Central Sleep Apnea–An Analysis From the SERVE-HF Major Substudy

Background

The SERVE-HF trial investigated the effect of treating central sleep apnoea (CSA) with adaptive servo-ventilation (ASV) in patients with heart failure with reduced ejection fraction (HFrEF).

Objective

The aim of the present ancillary analysis of the SERVE-HF major substudy (NCT01164592) was to assess the effects of ASV on the burden of nocturnal ventricular arrhythmias as one possible mechanism for sudden cardiac death in ASV-treated patients with HFrEF and CSA.

Methods

Three hundred twelve patients were randomized in the SERVE-HF major substudy [no treatment of CSA (control) vs. ASV]. Polysomnography including nocturnal ECG fulfilling technical requirements was performed at baseline, and at 3 and 12 months. Premature ventricular complexes (events/h of total recording time) and non-sustained ventricular tachycardia were assessed. Linear mixed models and generalized linear mixed models were used to analyse differences between the control and ASV groups, and changes over time.

Results

From baseline to 3- and 12-month follow-up, respectively, the number of premature ventricular complexes (control: median 19.7, 19.0 and 19.0; ASV: 29.1, 29.0 and 26.0 events/h; p = 0.800) and the occurrence of ≥1 non-sustained ventricular tachycardia/night (control: 18, 25, and 18% of patients; ASV: 24, 16, and 24% of patients; p = 0.095) were similar in the control and ASV groups.

Conclusion

Addition of ASV to guideline-based medical management had no significant effect on nocturnal ventricular ectopy or tachyarrhythmia over a period of 12 months in alive patients with HFrEF and CSA. Findings do not further support the hypothesis that ASV may lead to sudden cardiac death by triggering ventricular tachyarrhythmia.

Ventricular Arrhythmias in Patients with Implanted Cardiac Devices at High Risk of Obstructive Sleep Apnea

Background and Objectives: Patients with pre-existing cardiac disease have a higher prevalence of Obstructive Sleep Apnea (OSA). OSA has been associated with an increased risk of supraventricular and ventricular arrhythmia. We screened subjects with implanted pacemakers and automated implantable cardioverter defibrillators (AICD) for OSA with the Berlin Questionnaire and compared the incidence of ventricular arrhythmias and automated implantable cardioverter defibrillator (AICD) firing between high and low OSA risk groups. Materials and Methods: We contacted 648 consecutive patients from our arrhythmia clinic to participate in the study and performed final analyses on 171 subjects who consented and had follow-up data. Data were abstracted from the electronic health record for the incidence of non-sustained ventricular tachycardia (NSVT), ventricular tachycardia (VT), ventricular fibrillation (VF) and AICD firing and then compared between those at high versus low risk of OSA using the Berlin Questionnaire and multivariate negative binomial regression. Results: The average follow-up period was 24.2 ± 4.4 months. After adjusting for age, gender and history of heart failure, those subjects at high risk of OSA had a higher burden of NSVT vs. those with a low risk of OSA (33.4 ± 96.2 vs. 5.82 ± 17.1 episodes, p = 0.003). A predetermined subgroup analysis of AICD recipients also demonstrated a significantly higher burden of NSVT in the high vs. low OSA risk groups (66.2 ± 128.6 vs. 18.9 ± 36.7 episodes, p = 0.033). There were significant differences in the rates of VT, VF or AICD shock burden between the high and low OSA risk groups and in the AICD subgroup analysis. Conclusions: There was increased ventricular ectopy among pacemaker and AICD recipients at high risk of OSA, but the prevalence of VT, VF or AICD shocks was similar to those with low risk of OSA.

Impact of sleep-disordered breathing on ventricular tachyarrhythmias after left ventricular assist device implantation

Sleep-disordered breathing (SDB) is associated with an increased risk of adverse events in patients with heart failure (HF); however, its impact in patients implanted with a left ventricular assist device (LVAD) remains unclear. We aimed to investigate the prevalence of SDB in patients with LVAD and its impact on their clinical outcomes. Fifty consecutive patients with LVAD who underwent portable sleep monitoring between September 2017 and April 2018 were prospectively enrolled, and they were followed up for 170 ± 36 days. According to their respiratory disturbance indexes (RDIs), they were categorized into the SDB group (RDI ≥ 15, n = 12) and the non-SDB group (RDI < 15, n = 38). The incidence of adverse events during the follow-up period was investigated after enrollment. Multivariate logistic regression analysis revealed significant differences in SDB in LVAD-implanted patients in terms of the logarithmic transformation brain natriuretic peptide (BNP) values (p = 0.005). The optimal BNP cut-off value for SDB prediction in LVAD-implanted patients was 300 pg/mL (sensitivity: 58.3%, specificity: 94.7%). During follow-up, ventricular tachyarrhythmias (VTas) occurred significantly more frequently in the SDB group (4 [33%] vs. 2 [5%] patients, p = 0.02); Atrial tachyarrhythmia (ATa) also tended to occur more frequently in the SDB group (2 [25%] vs. 2 [2%] patients, p = 0.07). SBD was prevalent in 24% of the LVAD-implanted patients with advanced HF. Furthermore, SDB was significantly associated with high BNP levels and was also potentially associated with subsequent incidence of VTa in patients with LVAD.

Ventrikuläre Arrhythmien bei obstruktiver und zentraler Schlafapnoe

Hintergrund

Ventrikuläre Arrhythmien treten mit einer hohen Prävalenz auf und sind mit einer hohen Morbidität und Mortalität assoziiert. Sowohl die obstruktive (OSA) als auch die zentrale (ZSA) Schlafapnoe können auf Grund ihrer Pathophysiologie zu vermehrten ventrikulären Arrhythmien beitragen.

Ziel

Dieser Artikel soll die komplexen Zusammenhänge und Erkenntnisse jüngster Forschungen bezüglich schlafbezogenen Atmungsstörungen (SBAS) und ventrikulärer Arrhythmien und deren Therapiemöglichkeiten beleuchten.

Material und Methoden

Es erfolgte eine Literaturrecherche basierend auf prospektiven, retrospektiven, klinischen und experimentellen Studien sowie Reviews, Metaanalysen und aktuellen Leitlinien, die seit 2014 in der Medline-Datenbank gelistet wurden.

Ergebnisse

Es besteht ein bidirektionaler Zusammenhang zwischen der SBAS und ventrikulären Arrhythmien. Intermittierende Hypoxie, oxidativer Stress, wiederkehrende Arousals, intrathorakale Druckschwankungen und kardiales Remodeling tragen im Rahmen der SBAS zu einer erhöhten ventrikulären Arrhythmieneigung bei. Der Schweregrad der OSA, gemessen mittels Apnoe-Hypopnoe-Index, ist mit der Prävalenz ventrikulärer Arrhythmien assoziiert. Ähnliche Ergebnisse liegen für Patienten mit ZSA und Herzinsuffizienz vor. Studien zu ventrikulären Arrhythmien bei ZSA-Patienten ohne Herzinsuffizienz fehlen. Eine Positivdrucktherapie (PAP) bei OSA- oder ZSA-Patienten führte in verschiedenen Studien zu einer reduzierten Anzahl an ventrikulären Arrhythmien. Dieser Zusammenhang konnte jedoch nicht in allen Studien bestätigt werden. Ventrikuläre Arrhythmien treten bei der OSA gehäuft nachts auf, bei der ZSA gleichmäßig über den Tag verteilt.

Diskussion

Bisherige Studien weisen einen Zusammenhang zwischen der OSA bzw. der ZSA und ventrikulären Arrhythmien trotz unterschiedlicher Pathophysiologie nach. Hinsichtlich des Effektes der PAP auf ventrikuläre Arrhythmien bei Patienten mit OSA und ZSA sind weitere Studien erforderlich.

Ventricular arrhythmia in heart failure patients with reduced ejection fraction and central sleep apnoea

Cheyne–Stokes respiration (CSR) may trigger ventricular arrhythmia in patients with heart failure with reduced ejection fraction (HFrEF) and central sleep apnoea (CSA). This study determined the prevalence and predictors of a high nocturnal ventricular arrhythmia burden in patients with HFrEF and CSA (with and without CSR) and to evaluate the temporal association between CSR and the ventricular arrhythmia burden.

 This cross-sectional ancillary analysis included 239 participants from the SERVE-HF major sub-study who had HFrEF and CSA, and nocturnal ECG from polysomnography. CSR was stratified in ≥20% and <20% of total recording time (TRT). High burden of ventricular arrhythmia was defined as >30 premature ventricular complexes (PVCs) per hour of TRT. A sub-analysis was performed to evaluate the temporal association between CSR and ventricular arrhythmias in sleep stage N2.

 High ventricular arrhythmia burden was observed in 44% of patients. In multivariate logistic regression analysis, male sex, lower systolic blood pressure, non-use of antiarrhythmic medication and CSR ≥20% were significantly associated with PVCs >30·h⁻¹ (OR 5.49, 95% CI 1.51–19.91, p=0.010; OR 0.98, 95% CI 0.97–1.00, p=0.017; OR 5.02, 95% CI 1.51–19.91, p=0.001; and OR 2.22, 95% CI 1.22–4.05, p=0.009; respectively). PVCs occurred more frequently during sleep phases with versus without CSR (median (interquartile range): 64.6 (24.8–145.7) versus 34.6 (4.8–75.2)·h⁻¹ N2 sleep; p=0.006).

 Further mechanistic studies and arrhythmia analysis of major randomised trials evaluating the effect of treating CSR on ventricular arrhythmia burden and arrhythmia-related outcomes are warranted to understand how these data match with the results of the parent SERVE-HF study.

High ventricular arrhythmia burden occurs in 44% of heart failure patients with reduced ejection fraction and central sleep apnoea. Arrhythmia burden is higher in sleep phases with versus without Cheyne–Stokes respiration.https://bit.ly/2QBDamC

Arrhythmogenic mechanisms of acute obstructive respiratory events in a porcine model of drug-induced long QT

BACKGROUND

Obstructive sleep apnea is associated with increased risk of sudden cardiac death.

OBJECTIVE

The purpose of this study was to elucidate changes in ventricular repolarization and electromechanical interaction during obstructive respiratory events simulated by intermittent negative upper airway pressure (INAP) in pigs. We also investigated the effect of a reduced repolarization reserve in drug-induced long QT (LQT) following INAP-induced changes in ventricular repolarization.

METHODS

In sedated spontaneously breathing pigs, 75 seconds of INAP was applied by a negative pressure device connected to the endotracheal tube. Ventricular electromechanical coupling was determined by the electromechanical window (EMW) before (pre-INAP), during (INAP), and after INAP (post-INAP). Incidence rates of premature ventricular contractions (PVCs) were measured respectively. A drug-induced LQT was modeled by treating the pigs with the hERG1 blocker dofetilide (DOF).

RESULTS

Whereas QT interval increased during and decreased after INAP (pre-INAP: 273 ± 5 ms; INAP 281 ± 6 ms; post-INAP 254 ± 9 ms), EMW shortened progressively throughout INAP and post-INAP periods (pre-INAP 81 ± 4 ms; post-INAP 44 ± 7 ms). DOF shortened EMW at baseline. Throughout INAP, EMW decreased in a comparable fashion as before DOF (pre-INAP/+DOF 61 ± 7 ms; post-INAP/+DOF 14 ± 9 ms) but resulted in shorter absolute EMW levels. Short EMW levels were associated with increased occurrence of PVCs (pre-INAP 7 ± 2 ms vs post-INAP 26 ± 6 ms; P = .02), which were potentiated in DOF pigs (pre-INAP/+DOF 5 ± 2 ms vs post-INAP/+DOF 40 ± 8 ms; P = .006). Administration of atenolol prevented post-INAP EMW shortening and decreased occurrence of PVCs.

CONCLUSION

Transient dissociation of ventricular electromechanical coupling during simulated obstructive respiratory events creates a dynamic ventricular arrhythmogenic substrate, which is sympathetically mediated and aggravated by drug-induced LQT.

Correlation between apnea-hypopnea index and Tp-Te interval, Tp-Te/QT, and Tp-Te/QTc ratios in obstructive sleep apnea

Background

Obstructive sleep apnea (OSA) is a highly prevalent sleep disorder associated with important cardiovascular complications including ventricular arrhythmias. Tp‐Te interval, Tp‐Te/QT, and Tp‐Te/QTc ratios are repolarization indices representing ventricular arrhythmogenic potential. These parameters are associated with ventricular arrhythmias and sudden cardiac death. The aim of this study was to investigate the correlation between apnea–hypopnea index and Tp‐Te, Tp‐Te/QT, and Tp‐Te/QTc in OSA.

Methods

We screened a total of 280 patients who underwent overnight polysomnography (PSG) between the years 2012–2017 at our institution. Patients were assigned into four groups based on severity of apnea–hypopnea index: 70 with apnea–hypopnea index (AHI) <5 (control group), 71 with 5 ≤ AHI < 15, 63 with 15 ≤ AHI < 30, and 76 with AHI ≥ 30. Tp‐Te, Tp‐Te/QT, and Tp‐Te/QTc were measured.

Results

Compared to control group, repolarization parameters were significantly prolonged in other groups (Tp‐Te interval: 68.3 ± 6.8, 71.8 ± 6.3, 79.1 ± 5.5, and 85.1 ± 6.4 ms, p < .001; Tp‐Te/QT ratio: 167.5 ± 12.7, 181.7 ± 13.0, 202.2 ± 10.0 and 219.4 ± 13.5, p < .001; Tp‐Te/QTc ratio: 151.1 ± 16.6, 167.6 ± 16.6, 193.7 ± 14.4, and 225.5 ± 17.0, p < .001). There was a significant trend toward higher Tp‐Te, Tp‐Te/QT, and Tp‐Te/QTc across higher AHI categories. In a univariate regression analysis, body mass index, smoking status, Tp‐Te, and Tp‐Te/QTc were significantly associated with the severity of AHI in OSA. Tp‐Te (OR 1.629, 95% CI 1.393–1.906, p < .001), Tp‐Te/QTc (OR 1,333 95% CI 1.247–1.424, p < .001), and smoking status (OR 5.771, 95% CI 1.025–32.479, p = .047) were found to be significant independent predictors of severity of AHI in a multivariate analysis, after adjusting for other risk parameters.

Conclusions

Our study showed that Tp‐Te, Tp‐Te/QT, and Tp‐Te/QTc were prolonged in patients with OSA. There was significant correlation between apnea–hypopnea index and these parameters.

Meta-analysis of changes in the levels of catecholamines and blood pressure with continuous positive airway pressure therapy in obstructive sleep apnea

Stress from obstructive sleep apnea (OSA) stimulates catecholamine release consequently exacerbating hypertension. However, different studies have shown a conflicting impact of continuous positive airway pressure (CPAP) treatment in patients with OSA on catecholamine levels and blood pressure. We aimed to examine changes to catecholamine levels and blood pressure in response to CPAP treatment. We conducted a meta‐analysis of data published up to May 2020. The quality of the studies was evaluated using standard tools for assessing the risk of bias. Meta‐analysis was conducted using RevMan (v5.3) and expressed in standardized mean difference (SMD) for catecholamines and mean difference (MD) for systolic (SBP) and diastolic blood pressure (DBP). A total of 38 studies met our search criteria; they consisted of 14 randomized control trials (RCT) totaling 576 participants and 24 prospective cohort studies (PCS) of 547 participants. Mean age ranged between 41 and 62 year and body mass index between 27.2 and 35.1 kg/m². CPAP treatment reduced 24‐hour urinary noradrenaline levels both in RCT (SMD = −1.1; 95% confidence interval (CI): −1.63 to − 0.56) and in PCS (SMD = 0.38 (CI: 0.24 to 0.53). SBP was also reduced by CPAP treatment in RCT (4.8 mmHg; CI: 2.0‐7.7) and in PCS (7.5 mmHg; CI: 3.3‐11.7). DBP was similarly reduced (3.0 mmHg; CI: 1.4‐4.6) and in PCS (5.1 mmHg; CI: 2.3‐8.0). In conclusion, CPAP treatment in patients with OSA reduces catecholamine levels and blood pressure. This suggests that sympathetic activity plays an intermediary role in hypertension associated with OSA‐related stress.

Reducing cost and time to diagnosis and treatment of obstructive sleep apnea using ambulatory sleep study: a Singapore sleep centre experience

PURPOSE

The current gold standard for diagnosis of obstructive sleep apnea (OSA) is overnight in laboratory polysomnography (PSG). However, PSGs are expensive, labor-intensive, and have long wait times. An ambulatory sleep study device, the WatchPAT, has been shown to have high correlation for sleep indices measured compared with PSG (AASM, 2016). Use of the WatchPAT could potentially lead to shorter waiting times and earlier diagnosis of OSA (Lancet Resp Med 3:310-8, 2015). Our study aimed to investigate if WatchPAT reduces time to diagnosis and treatment of OSA in a tertiary healthcare setting. A secondary aim was to investigate the cost-benefit of an ambulatory sleep study.

METHODS

All patients who underwent diagnostic sleep studies in a single tertiary institution from 2014 to 2017 were retrospectively reviewed. Baseline characteristics and time from ordering of sleep study to prescription of continuous positive airway pressure were recorded. Data were categorized into two groups by type of diagnostic sleep study, PSG, and WatchPAT. The time to treatment and cost for diagnosis of OSA were compared between groups with the Paired T test/Wilcoxon signed-rank test.

RESULTS

Of 1898 patients who had diagnostic sleep studies over a 4-year period, 1660 patients (88%) underwent PSG and 238 patients (12%) underwent WatchPAT. Patients in the WatchPAT group had a shorter time to diagnosis (21 days versus 79.8 days, p < 0.001) and treatment (46.3 days versus 118.4 days, p < 0.001) compared to the PSG group. Cost-benefit calculation showed that this earlier treatment led to cost-saving of US $1179.50 per patient.

CONCLUSION

An ambulatory sleep study is an option for earlier access to diagnosis and treatment of OSA with the potential of considerable cost savings.

Improving exercise capacity and quality of life using non-invasive heart failure treatments: evidence from clinical trials

Endpoints of large-scale trials in chronic heart failure have mostly been defined to evaluate treatments with regard to hospitalizations and mortality. However, patients with heart failure are also affected by very severe reductions in exercise capacity and quality of life. We aimed to evaluate the effects of heart failure treatments on these endpoints using available evidence from randomized trials. Interventions with evidence for improvements in exercise capacity include physical exercise, intravenous iron supplementation in patients with iron deficiency, and - with less certainty - testosterone in highly selected patients. Erythropoiesis-stimulating agents have been reported to improve exercise capacity in anaemic patients with heart failure. Sinus rhythm may have some advantage when compared with atrial fibrillation, particularly in patients undergoing pulmonary vein isolation. Studies assessing treatments for heart failure co-morbidities such as sleep-disordered breathing, diabetes mellitus, chronic kidney disease and depression have reported improvements of exercise capacity and quality of life; however, the available data are limited and not always consistent. The available evidence for positive effects of pharmacologic interventions using angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, beta-blockers, and mineralocorticoid receptor antagonists on exercise capacity and quality of life is limited. Studies with ivabradine and with sacubitril/valsartan suggest beneficial effects at improving quality of life; however, the evidence base is limited in particular for exercise capacity. The data for heart failure with preserved ejection fraction are even less positive, only sacubitril/valsartan and spironolactone have shown some effectiveness at improving quality of life. In conclusion, the evidence for state-of-the-art heart failure treatments with regard to exercise capacity and quality of life is limited and appears not robust enough to permit recommendations for heart failure. The treatment of co-morbidities may be important for these patient-related outcomes. Additional studies on functional capacity and quality of life in heart failure are required.

Daytime QT by Routine 12-Lead ECG Is Prolonged in Patients with Severe Obstructive Sleep Apnea

Background

Obstructive sleep apnea (OSA) has been linked to sudden cardiac death (SCD). Prolonged QT is a recognized electrocardiographic (ECG) marker of abnormal ventricular repolarization linked to increased risk of SCD. We hypothesized that individuals with OSA have more pronounced abnormality in daytime QT interval.

Methods

We reviewed consecutive patients who underwent clinically indicated polysomnography with 12-lead ECG within 1 year at a single center. Heart rate-corrected QT interval (QTc) was compared by OSA severity class (normal/mild: apnea-hypopnea index (AHI) < 15/hr (n = 72); moderate: 15-30 (n = 72); moderate: 15-30 (n = 72); moderate: 15-30 (.

Results

A total of 249 patients were included. QTc was similar between the normal/mild and moderate groups, and the overall QTc trend increased across OSA (normal/mild: 435.6 ms; moderate: 431.36; severe: 444.4; p trend = 0.03). Abnormal QTc was found amongst 34% of male and 31% of female patients. Patients with severe OSA had longer QTc compared with normal/mild OSA (mean difference (95% CI): 10.0 ms (0.5, 19.0), p trend = 0.03). Abnormal QTc was found amongst 34% of male and 31% of female patients. Patients with severe OSA had longer QTc compared with normal/mild OSA (mean difference (95% CI): 10.0 ms (0.5, 19.0), p trend = 0.03). Abnormal QTc was found amongst 34% of male and 31% of female patients. Patients with severe OSA had longer QTc compared with normal/mild OSA (mean difference (95% CI): 10.0 ms (0.5, 19.0), p trend = 0.03). Abnormal QTc was found amongst 34% of male and 31% of female patients. Patients with severe OSA had longer QTc compared with normal/mild OSA (mean difference (95% CI): 10.0 ms (0.5, 19.0).

Conclusions

In a sleep clinic cohort, severe OSA was associated with higher QTc and clinically defined abnormal QTc compared with nonsevere OSA.

Arrhythmogenic mechanisms of obstructive sleep apnea in heart failure patients

Heart failure (HF) affects 23 million people worldwide and results in 300000 annual deaths. It is associated with many comorbidities, such as obstructive sleep apnea (OSA), and risk factors for both conditions overlap. Eleven percent of HF patients have OSA and 7.7% of OSA patients have left ventricular ejection fraction <50% with arrhythmias being a significant comorbidity in HF and OSA patients. Forty percent of HF patients develop atrial fibrillation (AF) and 30%-50% of deaths from cardiac causes in HF patients are from sudden cardiac death. OSA is prevalent in 32%-49% of patients with AF and there is a dose-dependent relationship between OSA severity and resistance to anti-arrhythmic therapies. HF and OSA lead to various downstream arrhythmogenic mechanisms, including metabolic derangement, remodeling, inflammation, and autonomic imbalance. (1) Metabolic derangement and production of reactive oxidative species increase late Na+ currents, decrease outward K+ currents and downregulate connexin-43 and cell-cell coupling. (2) remodeling also features downregulated K+ currents in addition to decreased Na+/K+ ATPase currents, altered Ca2+ homeostasis, and increased density of If current. (3) Chronic inflammation leads to downregulation of both Nav1.5 channels and K+ channels, altered Ca2+ homeostasis and reduced cellular coupling from alterations of connexin expression. (4) Autonomic imbalance causes arrhythmias by evoking triggered activity through increased Ca2+ transients and reduction of excitation wavefront wavelength. Thus, consideration of these multiple pathophysiological pathways (1-4) will enable the development of novel therapeutic strategies that can be targeted against arrhythmias in the context of complex disease, such as the comorbidities of HF and OSA.

The Association Between Obstructive Sleep Apnea and Arrhythmias

Obstructive sleep apnea (OSA) is caused by intermittent episodes of partial or complete closure of the upper airway, leading to apneic episodes while the patient is asleep. Atrial fibrillation (AF) leads to more than 750,000 hospitalizations per year and accounts for an estimated 130,000 deaths each year. The death rate from AF as the primary or a contributing cause of death has been rising for more than two decades. The material reviewed in this paper focuses on the association between OSA and arrhythmias. It goes into the details of the epidemiology, pathophysiology, and types of arrhythmias and the therapies seen in association with OSA.

Treatment of Adult Obstructive Sleep Apnea With Positive Airway Pressure: An American Academy of Sleep Medicine Systematic Review, Meta-Analysis, and GRADE Assessment

INTRODUCTION

The purpose of this systematic review is to provide supporting evidence for the clinical practice guideline for the treatment of obstructive sleep apnea (OSA) in adults using positive airway pressure (PAP).

METHODS

The American Academy of Sleep Medicine commissioned a task force of experts in sleep medicine. A systematic review was conducted to identify studies that compared the use of PAP with no treatment as well as studies that compared different PAP modalities. Meta-analyses were performed to determine the clinical significance of using PAP in several modalities (ie, continuous PAP, auto-adjusting PAP, and bilevel PAP), to treat OSA in adults. In addition, meta-analyses were performed to determine the clinical significance of using an in-laboratory versus ambulatory strategy for the initiation of PAP, educational and behavioral interventions, telemonitoring, humidification, different mask interfaces, and flexible or modified pressure profile PAP in conjunction with PAP to treat OSA in adults. Finally, the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) process was used to assess the evidence for making recommendations.

RESULTS

The literature search resulted in 336 studies that met inclusion criteria; 184 studies provided data suitable for meta-analyses. The data demonstrated that PAP compared to no treatment results in a clinically significant reduction in disease severity, sleepiness, blood pressure, and motor vehicle accidents, and improvement in sleep-related quality of life in adults with OSA. In addition, the initiation of PAP in the home demonstrated equivalent effects on patient outcomes when compared to an in-laboratory titration approach. The data also demonstrated that the use of auto-adjusting or bilevel PAP did not result in clinically significant differences in patient outcomes compared with standard continuous PAP. Furthermore, data demonstrated a clinically significant improvement in PAP adherence with the use of educational, behavioral, troubleshooting, and telemonitoring interventions. Systematic reviews for specific PAP delivery method were also performed and suggested that nasal interfaces compared to oronasal interfaces have improved adherence and slightly greater reductions in OSA severity, heated humidification compared to no humidification reduces some continuous PAP-related side effects, and pressure profile PAP did not result in clinically significant differences in patient outcomes compared with standard continuous PAP.

Ventricular Arrhythmias in Patients with Obstructive Sleep Apnea

Obstructive Sleep Apnea (OSA) is a prevalent condition thought to increase in the future. Being mostly undiagnosed, the most serious complications are cardiovascular diseases, among which are arrhythmias. Controversy remains as to whether OSA is a primary etiologic factor for ventricular arrhythmias, because of the high incidence of cardiovascular comorbidities in OSA patients. Howev-er, there is mostly a strong evidence of a relation between OSA and ventricular arrhythmias. A few mechanisms have been proposed to be responsible for this association and some electrocardiographic changes have also been demonstrated to be more frequent in OSA patients. Treatment of OSA with Continuous Positive Airway Pressure (CPAP) has the potential to reduce arrhythmias and confer a mortality benefit.

Sleep Apnea and Sudden Cardiac Death

Sleep plays an integral role in maintaining health and quality of life. Obstructive sleep apnea (OSA) is a prevalent sleep disorder recognized as a risk factor for cardiovascular disease (CVD) and arrhythmias. Sudden cardiac death (SCD) is a common and devastating event. Out-of-hospital SCD accounts for the majority of deaths from cardiac disease, which is the leading cause of death globally. A limited but emerging body of research have further elaborated on the link between OSA and SCD. In this article, we aim to provide a critical review of the existing evidence by addressing the following: What epidemiologic evidence exists linking OSA to SCD? What evidence exists for a pathophysiologic connection between OSA and SCD? Are there electrocardiographic markers of SCD found in patients with OSA? Does heart failure represent a major effect modifier regarding the relationship between OSA and SCD? What is the impact of sleep apnea treatment on SCD and cardiovascular outcomes? Finally, we elaborate on ongoing research to enhance our understanding of the OSA-SCD association.

Cardiac rhythm disorders in obstructive sleep apnea

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

Cardiovascular outcomes of continuous positive airway pressure therapy for obstructive sleep apnea

Obstructive sleep apnea is a common disorder with increased risk for cardiovascular morbidity and mortality. The first choice of treatment of obstructive sleep apnea is continuous positive airway pressure, which reduces excessive daytime sleepiness and improves quality of life in sleep clinic cohorts. Nevertheless, the majority of patients with cardiovascular disease and concomitant obstructive sleep apnea do not report daytime sleepiness, and adherence to treatment is insufficient particularly in this group. The current article aims to give an updated overview of the impact of continuous positive airway pressure therapy on cardiovascular outcomes mainly based on the observational studies and the recent randomized controlled trials.

Is obstructive sleep apnea associated with ventricular tachycardia? A retrospective study from the National Inpatient Sample and a literature review on the pathogenesis of Obstructive Sleep Apnea

BACKGROUND

Obstructive sleep apnea (OSA) is a known independent risk factor for a multiple cardiovascular morbidities and mortality. The association of OSA and ventricular arrhythmias is less well understood. The aim of this analysis is to study the relationship between OSA and ventricular tachyarrhythmias.

HYPOTHESIS

OSA is associated with increased ventricular arrhythmias.

METHODS

Data from the national inpatient sample (NIS) 2012 to 2014, were reviewed. Discharges associated with OSA were identified as the target population using the relevant ICD-9-CM codes. The primary outcome was a diagnosis of ventricular tachycardia (VT) in the OSA population. Secondary outcomes include the rate of ventricular fibrillation (VF) and cardiac arrest. Multivariable analyses were performed to examine the association of VT with multiple potential confounding clinical variables.

RESULTS

Of 18 013 878 health encounters, 943 978 subjects (5.24%) had a diagnosis of OSA. VT and VF were more prevalent among patients with OSA compared to those without a diagnosis of OSA (2.24% vs 1.16%; P < 0.001 and 0.3% vs 0.2%; P < 0.001, respectively). Odds ratio for cardiac arrest in OSA group was not statistically significant (1, 95% confidence interval 0.97-1.02, P < 0.76). In unadjusted analyses, all examined comorbidities were significantly more common in those with OSA, including diabetes mellitus, hypertension, chronic kidney disease, acute coronary syndrome, and heart failure.

CONCLUSION

OSA is associated with increased rates of ventricular tachyarrhythmia.

Cardiac effects of CPAP treatment in patients with obstructive sleep apnea and atrial fibrillation

PURPOSE

Obstructive sleep apnea (OSA) has been recognized as an independent risk factor for the development and progression of atrial fibrillation (AF). We aimed to investigate the changes in heart rate and atrial and ventricular ectopy after continuous positive airway pressure (CPAP) treatment in patients with OSA and AF.

METHODS

Consecutive patients with AF underwent ambulatory sleep monitoring, and OSA was defined as an Apnea-Hypopnea-Index (AHI) ≥ 5/h. Treated patients completed in-laboratory CPAP titration study. A 24-h ECG Holter was performed at baseline and at 3 and 6 months after CPAP treatment.

RESULTS

One hundred patients (70% males) with AF were included in the final analysis. OSA was diagnosed in 85% of patients. There were no significant changes in mean 24-h heart rate in patients with paroxysmal or permanent AF at 3 and 6 months of treatment compared to baseline. In patients with paroxysmal AF (n = 29), atrial and ventricular ectopy counts/24 h significantly decreased at 3 months compared to baseline (median (IQR) 351 (2049) to 57 (182), P = 0.002; 68 (105) to 16 (133), P = 0.01 respectively). At 6 months follow-up, the atrial ectopy count/24 h significantly decreased in patients with paroxysmal AF compared to baseline (median (IQR) 351 (2049) to 31 (113), P = 0.016, n = 14). In patients with permanent AF (n = 15), there was a significant reduction in ventricular ectopy count/24 h at 3 months compared to baseline (median (IQR) 100 (1116) to 33 (418), P = 0.02).

CONCLUSIONS

There is a significant decrease in atrial and ventricular ectopy count/24 h in patients with AF and OSA at 3 and 6 months of CPAP treatment compared to baseline.

Sleep: important considerations for the prevention of cardiovascular disease

PURPOSE OF REVIEW

Sleep plays many roles in maintenance of cardiovascular health. This review summarizes the literature across several areas of sleep and sleep disorders in relation to cardiometabolic disease risk factors.

RECENT FINDINGS

Insufficient sleep duration is prevalent in the population and is associated with weight gain and obesity, inflammation, cardiovascular disease, diabetes, and mortality. Insomnia is also highly present and represents an important risk factor for cardiovascular disease, especially when accompanied by short sleep duration. Sleep apnea is a well-characterized risk factor for cardiometabolic disease and cardiovascular mortality. Other issues are relevant as well. For example, sleep disorders in pediatric populations may convey cardiovascular risks. Also, sleep may play an important role in cardiovascular health disparities.

SUMMARY

Sleep and sleep disorders are implicated in cardiometabolic disease risk. This review addresses these and other issues, concluding with recommendations for research and clinical practice.

Noninvasive ventilation improves cardiac function in patients with chronic heart failure

Chronic heart failure (CHF) has been shown to be associated with an increased incidence of sleep-disordered breathing. Whether treatment with noninvasivepositive-pressure ventilation (NPPV), including continuous positive airway pressure, bi-level positive airway pressure and adaptive servo-ventilation, improves clinical outcomes of CHF patients is still debated. 2,832 CHF patients were enrolled in our analysis. NPPV was significantly associated with improvement in left ventricular ejection fraction (39.39% vs. 34.24%; WMD, 5.06; 95% CI, 3.30-6.81; P < 0.00001) and plasma brain natriuretic peptide level (268.23 pg/ml vs. 455.55 pg/ml; WMD, −105.66; 95% CI, [−169.19]-[−42.13]; P = 0.001). However, NPPV did not reduce all-cause mortality (0.26% vs. 0.24%; OR, 1.13; 95% CI, 0.93-1.37; P = 0.22) or re-hospitalization rate (57.86% vs. 59.38%; OR, 0.47; 95% CI, 0.19-1.19; P = 0.02) as compared with conventional therapy. Despite no benefits on hard endpoints, NPPV may improve cardiac function of CHF patients. These data highlight the important role of NPPV in the therapy of CHF.

The Effects of Continuous Positive Airway Pressure on Premature Ventricular Contractions and Ventricular Wall Stress in Patients with Heart Failure and Sleep Apnea

Background

We aimed to investigate the effects of continuous positive airway pressure (CPAP) treatment on electrocardiography (ECG), premature ventricular contraction load on 24-hour Holter recordings, and implantable cardioverter defibrillator (ICD) shocks in patients with obstructive sleep apnea syndrome (OSAS) and heart failure.

Methods

Patients with heart failure and ICD and patients with newly diagnosed OSAS were divided into two groups according to CPAP treatment. To compare the impact of CPAP on ECG parameters, both baseline and 6-month ECG, 24-hour Holter ECG, ambulatory blood pressure monitoring, echocardiography, polysomnography, and laboratory parameters were collected.

Results

CPAP treatment significantly reduced the frequency of premature ventricular contractions, T-peak to T-end, corrected QT, corrected QT dispersion, and T-peak to T-end/corrected QT ratio in the study group (p < 0.001 for all). Although the baseline NT-pro-BNP levels were similar between study and control groups, after six months, the NT-pro-BNP levels of the study group were significantly lower than that of the control group (39.18 ± 7.57 versus 46.11 ± 7.65; p < 0.001).

Conclusions

CPAP treatment in patients with heart failure and ICD and in patients with newly diagnosed OSAS may have beneficial effects on premature ventricular contractions and electrocardiographic arrhythmia indices and NT-pro-BNP levels. However, these results are needed to be clarified with further studies.

Obstructive sleep apnoea-hypopnoea and arrhythmias: new updates

AIMS

Obstructive sleep apnoea-hypopnoea (OSAH) is a prevalent condition characterized by repetitive pharyngeal collapse during sleep, leading to hypoxemia, hypercapnia, and persistent inspiratory efforts against an occluded airway until arousal. Several studies demonstrated that OSAH exerts acute and chronic effects on the cardiovascular system. Thus, although being a respiratory problem, the most important consequences of OSAH are cardiovascular, among which there are arrhythmias. The purpose of this review is to systematically analyse what has been recently published about the relationship between OSAH and every cardiac arrhythmia separately.

METHODS

We searched Pubmed, Scopus, Web of Science and Cochrane Collaboration databases for 'OSAHS arrhythmias', 'OSAH arrhythmias' and 'OSA arrhythmias'. We analyse 1298 articles and meta-analyses, excluding already edited reviews.

RESULTS

Arrhythmias, especially of ventricular origin, are frequent in OSAH. Ventricular premature beats, couplets and ventricular tachycardia runs are even more frequent in patients suffering from heart failure. They may be due to left heart remodelling, overwork and ischaemia and can explain at least some sudden deaths occurring between midnight and 6 a.m. Sinus pauses and atrioventricular blocks are increased according to the severity of the disturbance and may be reduced by continuous positive airway pressure therapy, preventing pace-maker implantation. Finally, atrial fibrillation, resistance against antiarrhythmic drugs and recurrences after surgical procedures are strongly related to OSAH.

CONCLUSION

Arrhythmias are frequent in OSAH. Treatment of OSAH may reduce some of them. An implantable cardioverter-defibrillator and continuous positive airway pressure should be considered in some patients.

Design of the effect of adaptive servo-ventilation on survival and cardiovascular hospital admissions in patients with heart failure and sleep apnoea: the ADVENT-HF trial

INTRODUCTION

Both types of sleep-disordered breathing (SDB), obstructive and central sleep apnoea (OSA and CSA, respectively), are common in patients with heart failure and reduced ejection fraction (HFrEF). In such patients, SDB is associated with increased cardiovascular morbidity and mortality but it remains uncertain whether treating SDB by adaptive servo-ventilation (ASV) in such patients reduces morbidity and mortality.

AIM

ADVENT-HF is designed to assess the effects of treating SDB with ASV on morbidity and mortality in patients with HFrEF.

METHODS

ADVENT-HF is a multicentre, multinational, randomized, parallel-group, open-label trial with blinded assessment of endpoints of standard medical therapy for HFrEF alone vs. with the addition of ASV in patients with HFrEF and SDB. Patients with a history of HFrEF undergo echocardiography and polysomnography. Those with a left ventricular ejection fraction ≤45% and SDB (apnoea-hypopnoea index ≥15) are eligible. SDB is stratified into OSA with ≥50% of events obstructive or CSA with >50% of events central. Those with OSA must not have excessive daytime sleepiness (Epworth score of ≤10). Patients are then randomized to receive or not receive ASV. The primary outcome is the composite of all-cause mortality, cardiovascular hospital admissions, new-onset atrial fibrillation requiring anti-coagulation but not hospitalization, and delivery of an appropriate discharge from an implantable cardioverter-defibrillator not resulting in hospitalization during a maximum follow-up time of 5 years.

CONCLUSION

The ADVENT-HF trial will help to determine whether treating SDB by ASV in patients with HFrEF improves morbidity and mortality.

Prevalence of Cardiac Arrhythmias in Asian Patients With Obstructive Sleep Apnea: A Singapore Sleep Center Experience

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) is associated with increased cardiovascular morbidity and mortality. Cardiac arrhythmias are common in patients with OSA. However, the prevalence and significance of cardiac arrhythmias in Asian patients with OSA are not well studied. The aim of this study is to determine the prevalence of cardiac arrhythmias in patients with OSA in Singapore and to evaluate possible factors that may predispose patients with OSA to arrhythmias.

METHODS

A retrospective study of 2,019 patients was carried out from January 2011 to December 2012 at a sleep center in a tertiary medical center. Of the population, 1,457 patients were found to have OSA and 144 patients were found to have cardiac arrhythmias. Data collected included patient demographics, comorbidities, and polysomnogram parameters.

RESULTS

The prevalence of cardiac arrhythmias in our OSA population is 8.0%, compared to that of primary snorers at 4.8% (P = .015). The univariate analysis revealed that older age, higher body mass index, comorbidities, and severity of OSA, including apnea-hypopnea index (AHI), lowest oxygen saturation (LSAT) and hypoxic time were correlated with a higher prevalence of cardiac arrhythmias (P < .05). However, the multivariate analysis showed that only age and body mass index were significantly correlated with arrhythmias. AHI, LSAT, and hypoxic time were no longer statistically significant.

CONCLUSIONS

Our study demonstrated that cardiac arrhythmias are common in patients with OSA in Singapore. It also suggests that given the different demographics of our population, ethnicity may play a significant role in the development of cardiovascular disease among patients with OSA.

COMMENTARY

A commentary on this article appears in this issue on page 1229.

Sleep Apnea: Types, Mechanisms, and Clinical Cardiovascular Consequences

Sleep apnea is highly prevalent in patients with cardiovascular disease. These disordered breathing events are associated with a profile of perturbations that include intermittent hypoxia, oxidative stress, sympathetic activation, and endothelial dysfunction, all of which are critical mediators of cardiovascular disease. Evidence supports a causal association of sleep apnea with the incidence and morbidity of hypertension, coronary heart disease, arrhythmia, heart failure, and stroke. Several discoveries in the pathogenesis, along with developments in the treatment of sleep apnea, have accumulated in recent years. In this review, we discuss the mechanisms of sleep apnea, the evidence that addresses the links between sleep apnea and cardiovascular disease, and research that has addressed the effect of sleep apnea treatment on cardiovascular disease and clinical endpoints. Finally, we review the recent development in sleep apnea treatment options, with special consideration of treating patients with heart disease. Future directions for selective areas are suggested.

Sleep-Disordered Breathing in Heart Failure - A Therapeutic Dilemma

Sleep-disordered breathing (SDB) occurs in approximately 50% of patients with reduced left ventricular ejection fraction receiving contemporary heart failure (HF) therapies. Obstructive (OSA) and central sleep apneas (CSA) interrupt breathing by different mechanisms but impose qualitatively similar autonomic, chemical, mechanical, and inflammatory burdens on the heart and circulation. Because contemporary evidence-based drug and device HF therapies have little or no mitigating effect on the acute or long-term consequences of such stimuli, there is a sound mechanistic rationale for targeting SDB to reduce cardiovascular event rates and prolong life. However, the promise of observational studies and randomized trials of small size and duration describing a beneficial effect of treating SDB in HF via positive airway pressure was not realized in 2 recent randomized outcome-driven trials: SAVE, which evaluated the cardiovascular effect of treating OSA in a cohort without HF, and SERVE-HF, which reported the results of a strategy of random allocation of minute-ventilation-triggered adaptive servo-ventilation (ASV) for HF patients with CSA. Whether effective treatment of either OSA or CSA improves the HF trajectory by reducing cardiovascular morbidity or mortality has yet to be definitively established. ADVENT-HF, designed to determine the effect of treating both CSA and non-sleepy OSA HF patients with a peak-airflow triggered ASV algorithm, could resolve this present clinical equipoise concerning the treatment of SDB.

Sleep-Disordered Breathing During Congestive Heart Failure: To Intervene or Not to Intervene?

Sleep-disordered breathing is common in heart failure patients and is associated with increased morbidity and mortality. Central sleep apnea occurs more commonly in heart failure-reduced ejection fraction, and obstructive sleep apnea occurs more frequently in heart failure with preserved ejection fraction. Although the two types of sleep-disordered breathing have distinct pathophysiologic mechanisms, both contribute to abnormal cardiovascular consequences. Treatment with continuous positive airway pressure for obstructive sleep apnea in heart failure has been well defined, whereas treatment strategies for central sleep apnea in heart failure continue to evolve. Unilateral transvenous neurostimulation has shown promise for the treatment of central sleep apnea. In this paper, we examine the current state of knowledge of treatment options for sleep-disordered breathing in heart failure.