Obstructive sleep apnea and the risk of ischemic stroke in patients with atrial fibrillation

Clinical characteristics and thrombotic risk of atrial fibrillation with obstructive sleep apnea: results from a multi-center atrial fibrillation registry study

BACKGROUND

Sleep apnea is a risk factor for atrial fibrillation (AF) but it is underdiagnosed. Whether obstructive sleep apnea (OSA) is correlated with thrombotic risk in AF remains unclear. The aim of the present study was to analyze the clinical characteristics and assess the thrombotic risk of AF with OSA.

METHODS

In the present registry study,1990 consecutive patients with AF from 20 centers were enrolled. The patients were divided into 2 groups depending on whether they presented with both AF and OSA. All the patients were followed up for 1 year to evaluate the incidences of stroke and non-central nervous system (CNS) embolism.

RESULTS

Of the 1990 AF patients, 70 (3.5%) and 1920 (96.5%) patients were in the OSA group and non-OSA group, respectively. The results of the multivariate logistic model analysis showed that male sex, body mass index (BMI), smoking, and major bleeding history were independent risk factors for patients with AF and OSA. The comparison of the Kaplan-Meier curves using the log-rank test revealed that AF with OSA was correlated with an increased risk of non-CNS embolism (p < 0.01). After multivariate adjustments were performed, OSA remained an independent risk factor for non-CNS embolism (HR 5.42, 95% CI 1.34-22.01, p = 0.02), but was not correlated with the risk of stroke in patients with AF.

CONCLUSIONS

The present study revealed that male sex, high BMI values, smoking, and major bleeding history were independent risk factors for patients with AF and OSA. Moreover, OSA was an independent risk factor for non-CNS embolism in AF. Our results indicate that non-CNS embolism requires focus in patients with AF and OSA.

Obstructive sleep apnea and influenza infection: a nationwide population-based cohort study

OBJECTIVES

Influenza infection could trigger acute myocardial infarction. Obstructive sleep apnea (OSA) increases risk for myocardial infarction. Evidence evaluating the risk of influenza in patients with OSA is limited. We aimed to investigate the association between OSA and influenza using a nationwide population-based data set.

METHODS

A total of 5483 individuals with OSA were enrolled from January, 2000, to December, 2012, and compared with a control group of 21,932 individuals who had never been diagnosed with OSA (at a 1:4 ratio propensity score matched by age, sex, index years, and comorbidities) in the context of subsequent influenza infection. Cox proportional hazard regression analysis was conducted to analyze the association between OSA and influenza incidence. We conducted sensitivity analyses to examine our finding.

RESULTS

During the 1.81 (±2.12) years of the follow-up period, the incidence rate of influenza infection was higher in the OSA group compared with the non-OSA group (36.40 and 30.09 per 100 person-years). After adjusting for age, sex, comorbidities, outpatients visits, the risk of influenza infection among patients with OSA was significantly higher (hazard ratio = 1.18; 95% confidence interval = 1.14-1.23; P < 0.001). Sensitivity analyses showed consistent positive association. Males with OSA had increased risk of influenza infection compared with males without OSA (adjusted HR, 1.21; 95% CI, 1.16-1.27; P value for interaction = 0.03).

CONCLUSIONS

This study found a significantly higher risk of influenza infection in patients with OSA, and sex acted as an effect modifier between OSA and risk of influenza infection.

Should we incorporate obstructive sleep apnea in CHA2DS2-VASc score?

Atrial fibrillation (AF) is considered a significant challenge in cardiovascular medicine related to significant morbidity and mortality. Obstructive sleep apnea (OSA) is associated with stroke and constitutes an important risk factor for AF. However, it is still ambiguous whether OSA is independently related to stroke or systemic embolism in AF patients, and whether or not OSA should be included in CHA2DS2-VASc score. In a recent study, the presence of OSA in patients with AF was associated with higher rates of adverse events, namely stroke and systemic embolism. Patients with OSA have higher CHA2DS2-VASc scores and mean CHA2DS2-VASc scores that increase with OSA severity. The addition of OSA to CHA2DS2-VASc resulted in improved discrimination, but this improvement was modest and clinically non-significant. However, cardiovascular risk factors that accompany OSA and not OSA per se might be responsible for the increased thromboembolic risk in these patients. It is noteworthy that patients with OSA with CHA2DS2-VASc <2 had a higher incidence of stroke compared to those without. Unfortunately, the event rates for stroke in these patients were too low to reach statistically validated conclusions. Therefore, it seems reasonable to suggest that in borderline stroke risk patients (CHA2DS2-VASc <2), the presence of OSA should be taken into account in the treatment decision. More studies are needed to elucidate whether or not OSA should be incorporated in CHA2DS2-VASc score.

Diagnosed Sleep Apnea and Cardiovascular Disease in Atrial Fibrillation Patients: The Role of Measurement Error from Administrative Data

BACKGROUND

Atrial fibrillation and obstructive sleep apnea are common conditions, but little is known about obstructive sleep apnea and cardiovascular risk among atrial fibrillation patients.

METHODS

Using the Truven Health MarketScan databases, we constructed a prospective cohort of atrial fibrillation patients from 2007 to 2014. Atrial fibrillation, obstructive sleep apnea, stroke, myocardial infarction, and confounders were defined using the International Classification of Disease-9-CM codes. We matched individuals with an obstructive sleep apnea diagnosis with up to five individuals without a diagnosis by age, sex, and enrollment date. Cox proportional hazards models adjusted for confounders and high-dimensional propensity scores. We included migraines as a control outcome. Bias analysis used published sensitivities and specificities to generate rate ratios adjusted for obstructive sleep apnea misclassification.

RESULTS

We matched 56,969 individuals with an obstructive sleep apnea diagnosis to 323,246 without. During a mean follow-up of 16 months, 3234 incident strokes and 4639 incident myocardial infarctions occurred. After adjustment, obstructive sleep apnea diagnosis was strongly associated with reduced risk of incident stroke (hazard ratio = 0.48, 95% confidence interval = 0.43, 0.53) and myocardial infarction (0.40, [0.37, 0.44]) and a smaller reduced risk of migraines (0.82, [0.68, 0.99]). Bias analysis produced wide-ranging or inestimable rate ratios adjusted for misclassification of obstructive sleep apnea.

CONCLUSIONS

Obstructive sleep apnea diagnosis in atrial fibrillation patients was strongly associated with reduced risk of incident cardiovascular disease. We discuss misclassification, selection bias, and residual confounding as potential explanations.

Risk of major cardiovascular and neurologic events with obstructive sleep apnea among patients with atrial fibrillation

BACKGROUND

Obstructive sleep apnea (OSA) is a known risk factor for atrial fibrillation (AF). However, it remains unclear whether OSA is independently associated with worse cardiovascular and neurological outcomes in patients with AF.

METHODS

We used the ORBIT-AF I and ORBIT-AF II to conduct a retrospective cohort study of 22,760 patients with AF with and without OSA. Adjusted multivariable Cox proportional hazards models was used to determine whether OSA was associated with increased risk for major adverse cardiac and neurologic events (MACNEs) (cardiovascular death, myocardial infarction, stroke/transient ischemic attack/non-central nervous system embolism (stroke/SE), and new-onset heart failure], combined and individually.

RESULTS

A total of 4,045 (17.8%) patients had OSA at baseline. Median follow-up time was 1.5 (interquartile range: 1-2.2) years, and 1,895 patients experienced a MACNE. OSA patients were younger (median [interquartile range] 68 [61-75] years vs 74 [66-81] years), were more likely male (70.7% vs 55.3%), and had increased body mass index (median 34.6 kg/m² [29.8-40.2] vs 28.7 kg/m² [25.2-33.0]). Those with OSA had a higher prevalence of concomitant comorbidities such as diabetes, chronic obstructive pulmonary disease, and heart failure. OSA patients had higher use of antithrombotic therapy. After adjustment, the presence of OSA was significantly associated with MACNE (hazard ratio: 1.16 [95% CI: 1.03-1.31], P = .011). OSA was also an independent risk factor for stroke/SE beyond the CHA₂DS₂-VASc risk factors (HR: 1.38 [95% CI 1.12-1.70], P = .003) but not cardiovascular death, myocardial infarction, new-onset heart failure, or major bleeding.

CONCLUSIONS

Among patients with AF, OSA is an independent risk factor for MACNE and, more specifically, stroke/SE.

Stroke risk stratification in atrial fibrillation: a review of common risk factors

Atrial Fibrillation (AF) has become a major global health concern being the most common sustained arrhythmia in clinical practice. Risk factors for AF include congestive heart failure, hypertension, increasing age and diabetes. Many of these factors also increase the risk for thromboembolism and ischemic stroke in AF patients. Great efforts have been made from the latter part of the 20th century towards developing an ideal stroke risk stratification tool in AF with the aim of reducing the incidence of stroke in AF patients and the limiting unnecessary use of thromboprophylaxis. The thromboembolic risks posed by AF with valvular heart disease are an important subgroup that contributes to a significant proportion of stroke in AF patients globally. We review the evolution of stroke risk stratification and summarize the guidelines for stroke prevention in non-valvular AF as well as AF with valvular heart disease, and the most recent recommendations on stroke prevention in AF patients. Abbreviations: AF: Atrial Fibrillation; ACS: Acute Coronary Syndrome; CAD: Coronary Artery Disease; CCF: Congestive Cardiac Failure; DM: Diabetes Mellitus; EHRA: Evaluated Heartvalves, Rheumatic or Artificial; ICH: Intracranial Hemorrhage; NOACs: Novel Oral Anticoagulants; OAC: Oral Anticoagulants; PAD: Peripheral Arterial Disease ; TIA: Transient Ischemic Attack; VHD: Valvular Heart Disease.

Obstructive Sleep Apnea in Children and Adolescents and the Risk of Major Adverse Cardiovascular Events: A Nationwide Cohort Study in Taiwan

STUDY OBJECTIVES

This study has investigated the risk of major adverse cardiovascular events (MACEs), including acute myocardial infarction, coronary artery disease, peripheral artery disease, and acute stroke, among children and adolescents (age younger than 20 years) with obstructive sleep apnea (OSA).

METHODS

In this study, the population-based National Health Insurance Research Database of Taiwan was used to identify patients in whom OSA had been first diagnosed between 2000 and 2015. Children and adolescents with OSA (n = 6,535) were included with 1:3 ratio by age, sex, and index year of control participants without OSA (n = 19,605). The Cox proportional regression model was used to evaluate the risk of MACEs in this cohort study.

RESULTS

After a 15-year follow-up, the incidence rate of MACEs was higher in the OSA cohort when compared with the non-OSA control cohort (15.97 and 8.20 per 100,000 person-years, respectively). After adjusting for covariates, the risk of MACEs among children and adolescents with OSA was still significantly higher (hazard ratio = 2.050; 95% confidence interval = 1.312-3.107; P = .010). No MACEs were found in the children and adolescents with OSA who received continuous airway positive pressure treatment or pharyngeal surgery.

CONCLUSIONS

This study found a significantly higher risk of MACEs in children and adolescents with OSA. These findings strongly suggest that clinicians should provide careful follow-up and medical treatment for children and adolescents with OSA.

Sleep disorders and the risk of stroke

INTRODUCTION

Stroke is a major cause of disability and death in the United States and across the world, and the incidence and prevalence of stroke are expected to rise significantly due to an aging population. Obstructive sleep apnea, an established independent risk factor for stroke, is a highly prevalent disease that is estimated to double the risk of stroke. It remains uncertain whether non-apnea sleep disorders increase the risk of stroke. Areas covered: This paper reviews the literature describing the association between incident stroke and sleep apnea, rapid eye movement sleep behavior disorder, restless legs syndrome, periodic limb movements of sleep, insomnia, and shift work. Expert commentary: Trials of continuous positive airway pressure for stroke prevention in sleep apnea patients have been largely disappointing, but additional trials that target populations not yet optimally studied are needed. Self-reported short and long sleep duration may be associated with incident stroke. However, abnormal sleep duration may be a marker of chronic disease, which may itself be associated with incident stroke. The relationship between non-apnea sleep disorders and incident stroke deserves further attention. Identification of specific non-apnea sleep disorders or sleep problems that convey an increased risk for stroke may provide novel targets for stroke prevention.

Obstructive sleep apnea and its effects on cardiovascular diseases: a narrative review

Obstructive sleep apnea (OSA) occurs in 5%-14% of adults but is often undiagnosed. Apneas cause acute physiological changes, including alveolar hypoventilation and pulmonary artery vasoconstriction; they also promote chronic vascular disease secondary to increased platelet adhesiveness, endothelial dysfunction, and accelerated atherosclerosis. The Sleep Heart Health Study demonstrated that OSA is a risk factor for stroke and that an increase of 1 unit in the apnea-hypopnea index increases stroke risk by 6% in men. Patients with OSA frequently have atrial fibrillation (AF). Patients with OSA and AF have an increased incidence of stroke compared with patients with only OSA. The treatment of OSA with CPAP reduces the incidence of stroke and decreases the recurrence rate of AF in patients undergoing pulmonary vein ablation procedures. Undertreated OSA has the potential to complicate the postoperative course of patients undergoing cardiac surgery and increase the frequency of arrhythmias and ischemic events. However, one prospective study demonstrated that OSA did not increase complications during the first 30 days following surgery but increased complications during the long-term follow-up. OSA is associated with increased atherosclerotic coronary disease and the development of coronary events and congestive heart failure. In summary, patients with OSA have an increased frequency of stroke and AF The treatment of these patients with CPAP reduces the frequency of stroke and AF recurrence rate in patients with AF undergoing either medical management or invasive procedures. However, well-designed clinical trials are necessary to answer critical questions regarding the management of OSA in patients with cardiovascular diseases.

Stroke risk assessment in atrial fibrillation: risk factors and markers of atrial myopathy

Atrial fibrillation (AF) is a complex phenomenon associated with electrical, mechanical, and structural abnormalities of the atria. Ischaemic stroke in AF is only partially understood, but the mechanisms are known to be related to the atrial substrate as well as the atrial rhythm. The temporal dissociation between timing of AF and occurrence of stroke has led to the hypothesis that fibrotic, prothrombotic atrial tissue is an important cause of thrombus formation in patients with AF, independent of the atrial rhythm. Current stroke risk scores are practical, but limited in their capacity to predict stroke risk accurately in individual patients. Stroke prediction might be improved by the addition of emerging risk factors, many of which are expressions of atrial fibrosis. The use of novel parameters, including clinical criteria, biomarkers, and imaging data, might improve stroke risk prediction and inform on optimal treatment for patients with AF and perhaps individuals only at risk of AF.