Obstructive Sleep Apnea Treatment and Atrial Fibrillation: A Need for Definitive Evidence

Incidence of arrhythmias in chronic obstructive pulmonary disease, obstructive sleep apnea, and overlap syndrome: A retrospective cohort study

BACKGROUND

New-onset arrhythmias are common in patients with chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA). However, scarce data exist regarding arrhythmia risk in overlap syndrome (OS), encompassing COPD and OSA.

OBJECTIVE

We compared the incidence of new-onset atrial and ventricular arrhythmias in patients with COPD, OSA, and OS.

METHODS

We conducted a retrospective cohort study using the TriNetX Network, comprising >140 million patients to identify patients with COPD, OSA, and OS. Patients with pre-existing arrhythmias were excluded. Propensity score matching (PSM) was used to adjust for demographics, comorbidities, and medications. Adjusted odds ratios (aORs) were estimated to compare incidence of arrhythmias across cohorts.

RESULTS

Between 2010 and 2020, a total of 2,438,454 patients with COPD only, 1,960,845 patients with OSA only, and 440,018 patients with OS (age ≥18 years) were identified. After PSM, we included 359,496 patients per cohort for the OS vs OSA-only comparison and 399,235 patients per cohort for the OS vs COPD-only comparison. Over a mean follow-up of 5.3 years, incidence of new-onset atrial fibrillation/flutter was 10.0% in OS vs 7.0% in COPD (aOR 1.472, 95% confidence interval [CI] 1.449-1.496) and 6.4% in OSA (aOR 1.568, 95% CI 1.541-1.595). Patients with OS had higher incidence of new-onset ventricular tachycardia and cardiac arrest than those with COPD (aOR 1.442 and 1.189, respectively) and OSA (aOR 1.645 and 1.777, respectively). Patients with COPD preceding OSA diagnosis had higher odds of new-onset arrhythmias.

CONCLUSION

Patients with OS have a higher incidence of new-onset atrial fibrillation/flutter, ventricular tachycardia, and cardiac arrest compared with those with OSA and COPD alone.

Obstructive sleep apnea and atrial fibrillation: insights from a bidirectional Mendelian randomization study

Background

Observational studies have suggested that obstructive sleep apnea (OSA) is in relation to atrial fibrillation (AF); however, these studies might be confounded and whether the relationship is causal remains unclear. We conducted a bidirectional Mendelian randomization (MR) study to clarify the causal inference between OSA and AF.

Methods

Genetic instruments for OSA and AF were obtained from genome-wide association studies. The fixed-effects inverse-variance weighted (IVW) method was used as the main method, supplemented by several sensitivity analyses. For replication, another AF dataset was used to validate the causal effect of OSA on AF. Furthermore, multivariable MR analyses were performed to obtain direct estimates adjusting for potential confounders.

Results

Genetic liability to OSA was found to be significantly associated with a higher AF risk in the fixed-effects IVW method [odds ratio (OR) 1.210; 95% CI 1.119–1.307; P = 1.51 × 10^–6]. The results were consistent in MR sensitivity analyses as well as in replication analyses, and the significance remained after adjusting for potential confounders. In the reverse MR analyses, there was no causal effect of AF on OSA.

Conclusions

Our study strengthened the causal evidence of genetically predicted OSA with a higher AF risk. Early screening and appropriate management of OSA might show anti-arrhythmic benefits.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-022-01180-5.

Risk of New-Onset Atrial Fibrillation Post-cavotricuspid Isthmus Ablation in Typical Atrial Flutter Without History of Atrial Fibrillation

Aims: The aim was to describe the incidence of atrial fibrillation (AF) after cavotricuspid isthmus (CTI) ablation in patients with typical atrial flutter (AFL) without history of AF and to identify risk factors for new-onset AF after the procedure.

Methods: A total of 191 patients with typical AFL undergoing successful CTI ablation were enrolled. Patients who had history of AF, structural heart disease, cardiac surgery, or ablation or who received antiarrhythmic drug after procedure were excluded. Clinical and electrophysiological data were collected.

Results: There were 47 patients (24.6%) developing new AF during a follow-up of 3.3 ± 1.9 years after CTI ablation. Receiver operating characteristic (ROC) curves indicated that the cut-off values of left atrial diameter (LAD) and CHA₂DS₂-VASc score were 42 mm and 2, with area under the curve of 0.781 and 0.550, respectively. The multivariable Cox regression analysis revealed that obstructive sleep apnea (OSA) [hazard ratio (HR) 3.734, 95% confidence interval (CI) 1.470–9.484, P = 0.006], advanced interatrial block (aIAB) (HR 2.034, 95% CI 1.017–4.067, P = 0.045), LAD > 42 mm (HR 2.710, 95% CI 1.478–4.969, P = 0.001), and CHA₂DS₂-VASc score > 2 (HR 2.123, 95% CI 1.118–4.034, P = 0.021) were independent risk factors of new-onset AF.

Conclusion: A combination of OSA, aIAB, LAD > 42 mm, and CHA₂DS₂-VASc > 2 was a strongly high risk for new-onset AF after ablation for typical AFL, and it had significance in postablation management in clinical practice.

Sleep apnoea has a dose-dependent effect on atrial remodelling in paroxysmal but not persistent atrial fibrillation: a high-density mapping study

AIMS

Obstructive sleep apnoea (OSA) associates with atrial fibrillation (AF), but the relationship of OSA severity and AF phenotype with the atrial substrate remains poorly defined. We sought to define the atrial substrate across the spectrum of OSA severity utilizing high-density mapping.

METHODS AND RESULTS

Sixty-six consecutive patients (male 71%, age 61 ± 9) having AF ablation (paroxysmal AF 36, persistent AF 30) were recruited. All patents underwent formal overnight polysomnography and high-density left atrial (LA) mapping (mean 2351 ± 1244 points) in paced rhythm. Apnoea-hypopnoea index (AHI) (mean 21 ± 18) associated with lower voltage (-0.34, P = 0.005), increased complex points (r = 0.43, P < 0.001), more low-voltage areas (r = 0.42, P < 0.001), and greater voltage heterogeneity (r = 0.39, P = 0.001), and persisted after multivariable adjustment. Atrial conduction heterogeneity (r = 0.24, P = 0.025) but not conduction velocity (r = -0.09, P = 0.50) associated with AHI. Patchy regions of low voltage that co-localized with slowed conduction defined the atrial substrate in paroxysmal AF, while a diffuse atrial substrate predominated in persistent AF. The association of AHI with remodelling was most apparent among paroxysmal AF [LA voltage: paroxysmal AF -0.015 (-0.025, -0.005), P = 0.004 vs. persistent AF -0.006 (-0.017, 0.005), P = 0.30]. Furthermore, in paroxysmal AF an AHI ≥ 30 defined a threshold at which atrial remodelling became most evident (nil-mild vs. moderate vs. severe: 1.92 ± 0.42 mV vs. 1.84 ± 0.28 mV vs. 1.34 ± 0.41 mV, P = 0.006). In contrast, significant remodelling was observed across all OSA categories in persistent AF (1.67 ± 0.55 mV vs. 1.50 ± 0.66 mV vs. 1.55 ± 0.67 mV, P = 0.82).

CONCLUSION

High-density mapping observed that OSA associates with marked atrial remodelling, predominantly among paroxysmal AF cohorts with severe OSA. This may facilitate the identification of AF patients that stand to derive the greatest benefit from OSA management.

The variability and burden of severe sleep apnea and the relationship with atrial fibrillation occurrence: analysis of pacemaker-detected sleep apnea

Study objectives

This was a pilot study to evaluate the long-term variability and burden of respiratory disturbance index (RDI) detected by pacemaker and to investigate the relationship between RDI and atrial fibrillation (AF) event in patients with pacemakers.

Methods

This was a prospective study enrolling patients implanted with a pacemaker that could calculate the night-to-night RDI. The mean follow-up was 348 ± 34 days. The RDI variability was defined as the standard deviation of RDI (RDI-SD). RDI burden was referred to as the percentage of nights with RDI ≥ 26. The patient with RDI ≥ 26 in more than 75% nights was considered to have a high sleep apnea (SA) burden. An AF event was defined as a daily AF duration > 6 h.

Results

Among 30 patients, the mean RDI of the whole follow-up period was 24.5 ± 8.6. Nine (30%) patients were diagnosed with high SA burden. Patients with high SA burden had a higher BMI (26.7 ± 4.8 vs 23.2 ± 3.9, p = 0.036), a higher prevalence of hypertension (86% vs 39%, p = 0.031), and a larger left ventricular diastolic diameter (49.2 mm vs 46.7 mm, p = 0.036). The RDI-SD in patients with a higher burden was significantly greater than that in the patients with less burden (10.7 ± 4.9 vs 5.7 ± 1.4, p = 0.036). Linear regression showed that participants with a higher RDI tended to have a higher SD (R = 0.661; p < 0.001). The mean RDI (OR = 1.118, 95%CI 1.008–1.244, p = 0.044) was associated with AF occurrence.

Conclusion

Using a metric such as burden of severe SA may be more appropriate to demonstrate a patient’s true disease burden.

Catheter ablation for atrial fibrillation: current indications and evolving technologies

Catheter ablation for atrial fibrillation (AF) has emerged as an important rhythm-control strategy and is by far the most common cardiac ablation procedure performed worldwide. Current guidelines recommend the procedure in symptomatic patients with paroxysmal or persistent AF who are refractory or intolerant to antiarrhythmic drugs. The procedure might also be considered as a first-line approach in selected asymptomatic patients. Data from large registries indicate that AF ablation might reduce mortality and the risk of heart failure and stroke, but evidence from randomized controlled trials is mixed. Pulmonary vein isolation using point-by-point radiofrequency or with the cryoballoon remains the cornerstone technique in AF ablation. Additional atrial ablation can be performed in patients with persistent AF, but its benefits are largely unproven. Technological advances in the past decade have focused on achieving durable vein isolation, reducing procedure duration and improving safety. Numerous exciting new technologies are in various stages of development. In this Review, we discuss the relevant data to support the recommended and evolving indications for catheter ablation of AF, describe the different ablation techniques, and highlight the latest advances in technology that aim to improve its safety and efficacy. We also discuss lifestyle modification strategies to improve ablation outcomes.

The Effect of Positive Airway Pressure Treatment of Obstructive and Central Sleep Apnea on the Recurrence of Atrial Fibrillation/Flutter Postintervention

STUDY OBJECTIVES

A strong association between sleep-disordered breathing (SDB) and atrial fibrillation and/or atrial flutter (AF) has consistently been observed in epidemiologic and interventional studies. The effect of positive airway pressure (PAP) on AF recurrence is inconclusive. This study sought to evaluate the effectiveness of PAP therapy for SDB on AF recurrence.

METHODS

This was a single-center, retrospective study conducted at a tertiary referral center. All adult patients who had SDB on polysomnography and underwent AF intervention (ablation or cardioversion) following polysomnography from January 1992-December 2014 were analyzed. Primary outcome was time to first-documented recurrence of AF after AF intervention by Kaplan-Meier estimates.

RESULTS

Among 30,188 patients with obstructive and central SDB, 429 had this diagnosis before AF intervention; 269 were "PAP-adherent users," the remaining 160 were "PAP-nonusers." Patients in both groups had similar age, sex, body mass index (BMI), ejection fraction, left atrial volume index (LAVI), antiarrhythmic medications, diabetes mellitus, systemic hypertension, and heart failure diagnoses. Time to recurrence of AF postintervention was no different in PAP-adherent users and nonusers (4.8 and 4.1 months respectively, P = .7). Cardioversion (compared to catheter ablation) was the strongest independent predictor of recurrent AF (hazard ratio [HR] 2.02, 95% confidence interval [CI] 1.39-2.94, P < .001). BMI and LAVI were also significant predictors of recurrence in adjusted analyses (HR 1.01, 95% CI 1.003-1.023, P = .10 and HR 1.01, 95% CI 1.001-1.019, P = .024 respectively).

CONCLUSIONS

Our study found no effect of PAP treatment of SDB on time to recurrence of AF post-AF intervention. Increased risk of recurrent AF was associated with high BMI and LAVI. These findings may affect the clinical management of AF.

The effect of atrial fibrillation intervention on nocturnal respiratory events in elderly patients with persistent AF

BACKGROUND

Sleep-disordered breathing (SDB) and atrial fibrillation (AF) are associated. This study investigated the impact of AF intervention on 6-month home sleep testing data.

METHODS

Sixty-seven patients (aged 66 to 86, 53% male) with persistent AF were randomized (1:1:1) to direct current cardioversion (DCCV) (22 patients), permanent pacemaker (PPM) + atrioventricular node ablation (AVNA) + DCCV (22 patients) or AF ablation (23 patients). Baseline and 6-month multichannel home sleep tests with the Watch-PAT200 (Itamar Medical Lts., Caesarea, Israel) were recorded. Implantable cardiac monitors (ICMs) (Medtronic Reveal XT, Minneapolis, Minnesota) in the DCCV and AF ablation groups, and PPM Holters in the 'pace and ablate' group were utilized to assess cardiac rhythm beat-to-beat throughout the study period.

RESULTS

The prevalence of moderate-to-severe SDB [apnoea-hypopnoea index (AHI) ≥ 15/h] was 60%. At 6 months there was no change in AHI, Epworth sleepiness scale, sleep time, % REM sleep, respiratory desaturation index or central apnoeic events. Twenty-five patients (15 AF ablation, 9 DCCV and 1 following DCCV post-AVNA) maintained SR at 6 months confirmed on ICMs in these patients. AHI fell from 29.8 ± 26.6/h to 22.2 ± 20.4/h; P = 0.049.

CONCLUSIONS

SDB is highly prevalent in patients with persistent AF. Restoration of sinus rhythm, and the associated long-term recovery of haemodynamics, is associated with a significant reduction in AHI. This implicates reversal of fluid shift from the lower limbs to the neck region, a key mechanism in the pathogenesis of SDB.

MiR-664a-3p expression in patients with obstructive sleep apnea: A potential marker of atherosclerosis

The early prediction of atherosclerosis (AS) is important in the management of obstructive sleep apnea patients (OSA). MicroRNA (miRNA) plays a vital role in the evolution of OSA and AS. Its differential expression may therefore serve as a diagnostic and prognostic biomarker of AS in OSA. The aim of this study was to identify specific serum miRNAs that could serve as a novel screening signature of AS in OSA patients. The specificity and sensitivity of these miRNAs in the early diagnosis of AS in OSA patients were then determined.The 128 participants in this study underwent maximum carotid intima-media thickness (CIMT) measurements and polysomnography and were divided into 4 groups: 27 healthy volunteers with normal max-CIMT, 31 healthy volunteers with increased max-CIMT, 35 OSA patients with normal max-CIMT, and 35 OSA patients with iCIMT. MiRNA was extracted from the 12 participants' serum (3 participants each groups) and used to establish miRNA libraries for deep sequencing. A total of 116 participants were quantified by qRT- PCR. Correlations between differential expression of miRNAs and CIMT were assessed using the Spearman correlation coefficient. Our study was approved by the Ethics Committee of our hospital and was conducted in line with the Helsinki Declaration.MiR-664a-3p expression was quantified by qRT-PCR. Correlations between miR-664a-3p expression and CIMT were assessed using the Spearman correlation coefficient. The results showed that the miR-664a-3p was downregulated in the OSA, OSA with iCMIT, and nCIMT groups compared with the control group.The demonstrated potential of circulating miR-664a-3p as a noninvasive marker of AS in essential OSA patients should be confirmed in further studies.

Should We Perform Catheter Ablation for Asymptomatic Atrial Fibrillation?

Since the original description of atrial fibrillation ablation, numerous studies have demonstrated the superiority of catheter ablation over pharmacological therapy for maintenance of sinus rhythm in patients with both paroxysmal and persistent atrial fibrillation. However, to date, no randomized studies have been powered to demonstrate a mortality or stroke reduction benefit of rhythm control with catheter ablation over a rate control strategy. The results of such ongoing studies are not expected until 2018 or 2019. Thus, the only indication for atrial fibrillation ablation in recent guidelines has been the presence of symptoms. However, up to 40% of an atrial fibrillation population may be asymptomatic. In 2017, in the absence of randomized studies, are there nevertheless data that support atrial fibrillation ablation in asymptomatic patients?

OSA and Cardiac Arrhythmogenesis: Mechanistic Insights

A surge of data has reproducibly identified strong associations of OSA with cardiac arrhythmias. As an extension of epidemiologic and clinic-based findings, experimental investigations have made strides in advancing our understanding of the putative OSA and cardiac arrhythmogenesis mechanistic underpinnings. Although most studies have focused on the links between OSA and atrial fibrillation (AF), relationships with ventricular arrhythmias have also been characterized. Key findings implicate OSA-related autonomic nervous system fluctuations typified by enhanced parasympathetic activation during respiratory events and sympathetic surges subsequent to respiratory events, which contribute to augmented arrhythmic propensity. Other more immediate pathophysiologic influences of OSA-enhancing arrhythmogenesis include intermittent hypoxia, intrathoracic pressure swings leading to atrial stretch, and hypercapnia. Intermediate pathways by which OSA may trigger arrhythmia include increased systemic inflammation, oxidative stress, enhanced prothrombotic state, and vascular dysfunction. Long-term OSA-associated sequelae such as hypertension, atrial enlargement and fibrosis, ventricular hypertrophy, and coronary artery disease also predispose to cardiac arrhythmia. These factors can lead to a reduction in atrial effective refractory period, triggered and abnormal automaticity, and promote slowed and heterogeneous conduction; all of these mechanisms increase the persistence of reentrant arrhythmias and prolong the QT interval. Cardiac electrical and structural remodeling observed in OSA animal models can progress the arrhythmogenic substrate to further enhance arrhythmia generation. Future investigations clarifying the contribution of specific OSA-related mechanistic pathways to arrhythmia generation may allow targeted preventative therapies to mitigate OSA-induced arrhythmogenicity. Furthermore, interventional studies are needed to clarify the impact of OSA pathophysiology reversal on cardiac arrhythmogenesis and related adverse outcomes.

Variability in obstructive sleep apnea: Analysis of pacemaker-detected respiratory disturbances

BACKGROUND

Obstructive sleep apnea (OSA) is associated with several cardiovascular conditions. Some pacemakers feature specific algorithms detecting respiratory cycles and deriving indices well correlated with the identification of polysomnography-confirmed severe OSA.

OBJECTIVES

The purposes of this study were to analyze respiratory disturbances measured by a validated algorithm in clinical practice and to describe their variability over time and their association with atrial fibrillation.

METHODS

Fifty-eight patients implanted with dual-chamber LivaNova REPLY 200 DR or KORA 100 DR pacemakers measuring a respiratory disturbance index (RDI) were included. An RDI >20 events per hour of sleep is well correlated with severe OSA as determined by polysomnography. Patients with >10% nights with invalid RDI measurements were excluded.

RESULTS

The RDI could be measured during 98% of nights. During a mean follow-up of 187 ± 123 days, the individual mean RDI was 19.9 ± 12.7 and was superior to 20 in 24 patients (41%). An RDI >20 events/h in at least 1 night was observed in 52 patients (90%). The mean day-to-day RDI variability in individual patients was 19% ± 21%. Patients with the highest burden of severe OSA (as defined by ≥75% of nights with RDI >20 events/h) were older, had a higher prevalence of hypertension, and were more often implanted for atrioventricular block than patients with lower burden of severe OSA. No RDI burden or cutoff was a predictor of atrial fibrillation occurrence.

CONCLUSION

OSA is frequent in patients with a pacemaker and is reliably detected by pacemakers. OSA is highly variable and could probably be best analyzed in terms of burden.