OSA Is a Risk Factor for Recurrent VTE

Impact of Obstructive Sleep Apnea on Disease Severity and Adverse Outcomes in Patients with Acute Pulmonary Embolism

Purpose

Acute pulmonary embolism (PE) poses a life-threatening risk with high mortality rates. While the coexistence of PE and obstructive sleep apnea (OSA) is gaining recognition, its influence on PE severity and prognosis remains uncertain. This study aims to investigate the associations between OSA and disease severity, as well as outcomes, in patients with acute PE.

Patients and Methods

We conducted a retrospective cohort study on patients diagnosed with acute PE who had undergone previous cardiorespiratory polygraphy. OSA severity was assessed using the apnea-hypopnea index (AHI) derived from cardiorespiratory polygraphy. The severity of acute PE was evaluated using the simplified Pulmonary Embolism Severity Index (sPESI) score. Logistic regression analysis was performed to investigate the associations between AHI and the risk of belonging to the sPESI≥1 group. Cox regression analysis was used to examine the relationship between AHI and long-term adverse events, defined as a composite of all-cause mortality and non-fatal cardiovascular events.

Results

Among 145 acute PE patients (mean age 62.2 years, 49.7% male), 94 (64.8%) had OSA. Patients with OSA had a significantly higher proportion of sPESI≥1 (89.4% vs 68.6%, p=0.002) than non-OSA patients. Each unit increase in AHI was associated with a 15% increased risk of severe PE (sPESI≥1) (odds ratio: 1.15, 95% CI 1.05-1.26, p=0.002) after adjusting for confounders. During a median follow-up of 15.2 months, 27 (18.6%) patients experienced adverse events. Increased AHI independently predicted a higher risk of adverse events (hazard ratio: 1.03, 95% CI: 1.00-1.05, p=0.026), even after adjusting for potential confounders. AHI ≥8 events/h was associated with a significantly higher adjusted hazard ratio of 2.56 (95% CI: 1.15-5.72, p=0.022) for adverse events compared to AHI <8 events.

Conclusion

OSA is common in acute PE patients and is linked to increased disease severity and adverse outcomes. Implementing routine OSA screening and management may aid risk stratification and improve outcomes in acute PE patients.

Impact of obstructive sleep apnea on outcomes of pulmonary embolism: A systematic review and meta‑analysis

The current review aimed to assess the effect of obstructive sleep apnea (OSA) on the severity and outcomes of pulmonary embolism (PE). PubMed, Embase, ScienceDirect, CENTRAL and Google Scholar were searched for studies assessing the impact of OSA on severity and outcomes of PE. A total of 12 studies were included. Meta-analysis revealed that simplified PE severity index of >1 and pulmonary artery obstruction index score was significantly higher in patients with OSA as compared with controls, but there was no difference in right ventricle to left ventricle short-axis diameter. The need for non-invasive ventilation was significantly higher in patients with OSA but there was no difference in the need for mechanical ventilation. Patients with OSA had a significantly higher incidence of recurrence of PE. Meta-analysis also showed a statistically significantly lower risk of in-hospital mortality in patients with OSA as compared with controls, but without any difference in the risk of late mortality. Adjusted data on mortality indicated a significantly lower risk of mortality in PE patients with comorbid OSA. Limited data shows that comorbid OSA increases the severity of PE but has no effect on right ventricular function. OSA may increase the risk of recurrent PE. Paradoxically, the presence of OSA may also reduce the risk of in-hospital mortality. Results must be interpreted with caution owing to high inter-study heterogeneity and lack of matching of baseline characteristics. Current evidence needs to be confirmed by high-quality prospective studies.

How does sleep apnea impact outcomes following primary total hip arthroplasty for femoral neck fractures: a matched-control analysis

BACKGROUND

Cross-sectional studies have demonstrated that the prevalence of sleep apnea (SA) to be increasing within the United States. While studies have shown the association of SA and its association on complications following elective orthopedic procedures, well-powered studies investigating its impact in a traumatic setting are limited. The purpose of this study was to determine whether SA patients undergoing primary total hip arthroplasty (THA) for femoral neck fractures have higher rates of: (1) hospital lengths of stay (LOS); (2) readmissions; (3) complications; and (4) healthcare expenditures.

METHODS

The 100% Medicare Standard Analytical Files was queried from 2005 to 2014 for patients who sustained femoral neck fractures and were treated with primary THA. The study group consisted of patients with concomitant diagnoses of SA, whereas patients without SA served as controls. Study group patients were matched to controls in a 1:5 ratio by age, sex, and various comorbid conditions. Demographics of the cohorts were compared using Pearson's chi-squared analyses, and multivariate logistic regression analyses were used to calculate the odds (OR) of the effects of SA on postoperative outcomes. A p value less than 0.006 was considered to be statistically significant.

RESULTS

The final query yielded 24,936 patients within the study (n = 4166) and control (n = 20,770) cohorts. SA patients had significantly longer in-hospital LOS (6 vs. 5 days, p < 0.0001) but similar readmission rates (24.12 vs. 20.50%; OR: 1.03, p = 0.476). SA patients had significantly higher frequency and odds of developing medical complications (72.66 vs. 43.85%; OR: 1.57, p < 0.0001), and higher healthcare costs ($22,743.79 vs. $21,572.89, p < 0.0001).

CONCLUSION

SA is associated with longer in-hospital LOS, higher rates of complications and healthcare expenditures. This study is vital as it can allow orthopaedists to educate patients with SA on the potential complications which may occur following their procedure.

LEVEL OF EVIDENCE

III.

Sleep Apnea and Postoperative Medical Complications and Health Care Expenditures Following Open Reduction and Internal Fixation of Bimalleolar Ankle Fractures

INTRODUCTION

Sleep Apnea (SA) is a common sleep disorder that increases postoperative morbidity. There is limited research on how SA influences outcomes following operative fixation of ankle fractures. Therefore, the aim of this study was to determine whether patients who undergo surgical fixation for bimalleolar ankle fractures have higher rates of medical complications and health care expenditures.

METHODS

A retrospective review from January 1, 2005 to March 31, 2014 was conducted using the parts A and B Medicare Data from PearlDiver database. Patients with and without SA on the day of the primary open reduction and internal fixation (ORIF) of their bimalleolar ankle fractures were queried using the International Classification of Diseases, Ninth Revision codes. Welch'st-tests were used to compare costs of care. A multivariate binomial logistic regression model was used to calculate the odds ratio (OR) of adverse events. A P-value <.001 was considered statistically significant.

RESULTS

There were 20 560 patients (SA = 3150; comparison cohort = 17 410) who underwent ORIF for bimalleolar ankle fractures during the study period. Sleep apnea patients were found to have significantly higher rates and odds of 90-day medical complications (21.42% vs 7.47%, OR: 3.11, P < .0001) and 90-day costs of care ($7213.12 vs $5415.79, P < .0001).

CONCLUSION

This research demonstrates an increased risk of postoperative medical complications and health care costs among patients with SA undergoing ORIF for bimalleolar ankle fractures.

LEVEL OF EVIDENCE

Therapeutic, Level IV: Retrospective.

Obstructive Sleep Apnea as a Risk Factor for Venous Thromboembolism: A Systematic Review

Obstructive sleep apnea (OSA), is a prevalent condition characterized by repeated episodes of pharyngeal airway obstruction resulting in hypopnea and apnea episodes during sleep leading to nightly awakenings. OSA is a major contributor to the healthcare burden worldwide due to its high cardiovascular morbidity and mortality. There is growing evidence to support a pathophysiological link between OSA and venous thromboembolism (VTE). The pro-inflammatory state along with intermittent hypoxia that is invoked in OSA is associated with blood hypercoagulability, venous stasis, and endothelial dysfunction leading to deep vein thrombosis (DVT) and pulmonary embolism (PE). In this systematic review, we aim to analyze and assess the available literature on OSA and VTE (or DVT/PE) to determine whether OSA is an independent risk factor for VTE.

Association between obstructive sleep apnea and venous thromboembolism recurrence: results from a French cohort

Background

Growing evidence suggests the relationship between obstructive sleep apnea (OSA) and venous thromboembolism (VTE). Few studies focused on VTE recurrence risk associated with OSA after anticoagulation cessation.

Methods

In a prospective cohort study, patients with documented VTE, were followed for an indefinite length of time and VTE recurrence were documented and adjudicated. The primary outcome was recurrent VTE after anticoagulation discontinuation. Secondary outcomes included all-cause mortality and the clinical presentation of VTE. Univariable and multivariable analyses were performed to identify risk factors for recurrence and mortality.

Results

Among the 2109 patients with documented VTE included, 74 patients had moderate to severe OSA diagnosis confirmed by home sleep test or polysomnography. During a median follow-up of 4.8 (interquartile range 2.5–8.0) years recurrent VTE occurred in 252 patients (9 with OSA and 243 without OSA). The recurrence risk in the univariable and multivariable analysis was not increased in patients with OSA, regardless of the time of diagnosis (before or after index VTE or pooled). VTE phenotype was significantly more often PE with or without associated deep vein thrombosis in the first event and recurrence for OSA patients compared to non-OSA patients. The risk of death was not increased in the OSA population compared to non-OSA patients in multivariable analysis.

Conclusions

In patients with OSA and VTE, the risk of all-cause mortality and VTE recurrence after anticoagulation discontinuation was not increased compared to non-OSA patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12959-021-00358-8.

Obstructive Sleep Apnea, Hypercoagulability, and the Blood-Brain Barrier

Obstructive sleep apnea (OSA) is characterized by repeated episodes of intermittent hypoxia (IH) and is recognized as an independent risk factor for vascular diseases that are mediated by a multitude of mechanistic pathophysiological cascades including procoagulant factors. The pro-coagulant state contributes to the development of blood clots and to the increase in the permeability of the blood-brain barrier (BBB). Such alteration of BBB may alter brain function and increase the risk of neurodegenerative diseases. We aim to provide a narrative review of the relationship between the hypercoagulable state, observed in OSA and characterized by increased coagulation factor activity, as well as platelet activation, and the underlying neural dysfunction, as related to disruption of the BBB. We aim to provide a critical overview of the existing evidence about the effect of OSA on the coagulation balance (characterized by increased coagulation factor activity and platelet activation) as on the BBB. Then, we will present the emerging data on the effect of BBB disruption on the risk of underlying neural dysfunction. Finally, we will discuss the potential of OSA therapy on the coagulation balance and the improvement of BBB.

Severity of Sleep Apnea and COVID-19 Illness

Objective

To characterize the relationship between severity of sleep apnea and coronavirus disease 2019 (COVID-19) hospitalization and severe illness.

Study Design

Retrospective cohort study.

Setting

Montefiore Health System in the Bronx, New York.

Methods

The data set consisted of adult patients with an active diagnosis of obstructive sleep apnea in the past 2 years and a positive severe acute respiratory syndrome coronavirus 2 quantitative polymerase chain reaction test at our institution between March 16, 2020, and May 26, 2020. Sleep apnea severity and continuous positive airway pressure compliance data were abstracted from the electronic medical record. The International Classification of Diseases, 10th Revision was used to classify comorbidities.

Results

A total of 461 patients with sleep apnea tested positive for COVID-19, of whom 149 were excluded for missing data in the electronic medical record. Patients with moderate and severe sleep apnea had higher rates of COVID-19 hospitalization compared to those with mild sleep apnea (P = .003). This association was reduced when accounting for confounders, most notably the Charlson Comorbidity Index, a measure of comorbid illness burden. Moderate and severe sleep apnea were associated with increased Charlson Comorbidity Indices, compared to mild sleep apnea (P = .01). Sleep apnea severity was not associated with a composite outcome of mechanical ventilation, intensive care unit admission, and death.

Conclusion

Sleep apnea severity was associated with the Charlson Comorbidity Index and may be a risk factor for COVID-19 hospitalization. We found no evidence that sleep apnea severity among hospitalized patients was associated with a composite outcome of mechanical ventilation, intensive care unit admission, and death.

Outcomes of patients hospitalized for acute pulmonary embolism by obstructive sleep apnea status

Pulmonary embolism (PE) is a major cause of cardiovascular morbidity and mortality. Obstructive sleep apnea (OSA) is increasingly recognized in the aging population, especially with the rising obesity epidemic. The impact of OSA on inpatient mortality in PE is not well understood. We used the Nationwide Inpatient Sample databases from 2005 to 2016 to identify 755,532 acute PE patients (age≥18 years). Among these, 61,050 (8.1%) were OSA+. Temporal trends in length of stay, inpatient mortality, and its association with OSA in PE patients were analyzed. The proportion of PE patients who were OSA+ increased from 2005 to 2016. OSA+ PE patients were younger and predominantly men. Despite a higher prevalence of traditional risk factors for inpatient mortality in OSA+ patients, OSA was associated with a lower risk of mortality in PE patients (odds ratio, 95% confidence interval; p: unadjusted 0.56, 0.53–0.58; p < 0.0001 and adjusted 0.55, 0.52–0.58; p < 0.0001). Overall mortality and length of stay in PE patients decreased over time. Relative to OSA– patients, there was a slight increase in mortality among OSA+ PE patients over time, although the length of stay remained unchanged between the two groups. In conclusion, OSA+ PE patients had a lower inpatient mortality compared to OSA– patients despite a higher prevalence of traditional mortality risk factors. Secondary pulmonary hypertension related to OSA with preconditioning of the right ventricle to elevated afterload may potentially explain the protective effect of OSA on mortality in PE. However, mechanistic studies need to further elucidate the links behind this association.

Management and Prevention of Cerebrovascular Accidents in SARS-CoV-2-Positive Patients Recovering from COVID-19: a Case Report and Review of Literature

We discuss the current understanding of COVID-19’s neurological implications, their basis, and the evolving clinical consensus with a focus on cerebrovascular stroke. We further illustrate the potential significance of these implications with the aid of an accompanying case report outlining the disease course and treatment of a COVID-19 patient suffering from ischemic stroke and pulmonary embolism. The ever-growing strain on the global healthcare system due to the spread of the novel coronavirus SARS-CoV-2 requires focused attention on urgent care of independent, coexisting, and associated comorbidities, including cerebrovascular accidents. For illustration purposes, we outline the case of a 68-year-old female presenting with COVID-19 subsequently complicated by bilateral pulmonary embolism and a right-sided cerebrovascular accident. The patient was successfully managed pharmacologically and discharged without significant neurological deficit. The evidence for a hypercoagulable state in this patient along with discussion of mechanistic bases, corroborative evidence from the literature, along with relevant guidance on screening, treatment, and prophylaxis is offered. Greater study of the pathogenesis of COVID-19-related cerebrovascular complications and revisiting current guidelines on their management including potentially heightened levels of thromboprophylaxis are warranted.

Procoagulant State of Sleep Apnea Depends on Systemic Inflammation and Endothelial Damage

INTRODUCTION

Growing evidence shows a hypercoagulable state in obstructive sleep apnea (OSA) that could be a risk factor for thromboembolic disease.

OBJECTIVES

We aimed to elucidate mechanisms involved in the procoagulant profile observed in patients with OSA and to investigate the potential utility of global tests in its characterization.

METHODS

Thirty-eight patients with severe OSA without previous history of thrombosis and nineteen healthy age- and sex-matched controls were included. Kinetic of clot formation was determined using rotational thromboelastometry. Haemostatic capacity of plasma and microparticles was determined by Calibrated Automated Thrombinography. Platelet surface receptors, activation markers and formation of platelet/leukocytes aggregates were analyzed by flow cytometry.

RESULTS

Thromboelastometry showed a procoagulant state in patients with OSA that did not seem to be related to a basal activation of platelets but by the increased existence of platelet/leukocyte aggregates. Patients with OSA presented many signs of endothelial damage such as increased plasma levels of E-selectin and cfDNA and enhanced thrombin generation due to the presence of microparticles rich in tissue-factor, which is related to OSA severity.

CONCLUSIONS

OSA induces an enhancement in the dynamics of clot formation which appears to be caused by at least two pathological mechanisms. First, a greater formation of platelet-leukocyte aggregates; secondly, endothelial damage which provokes a greater procoagulant potential due to the increase in tissue factor-rich microparticles. Moreover, this study has identified thromboelastometry and thrombin generation assay as useful tools to evaluate the prothrombotic state in these patients.

The role of obstructive sleep apnea on the prognosis of pulmonary embolism: a systemic review and meta-analysis

PURPOSE

The relationship between obstructive sleep apnea (OSA) and pulmonary embolism (PE) has been reported by some studies but the underlying mechanism remains unclear. We aimed to systematically assess the role of OSA on the disease prognosis of PE.

METHODS

We searched for studies on the relationship of OSA and the prognosis of PE published up to February 2020 among PubMed, Web of Science, EMBASE, and Cochrane Library databases. Two independent reviewers conducted the process of study search and screening, quality assessment, and data extraction. Meta-analysis was carried out using RevMan 5.3.

RESULTS

A total of 9 articles were included, and the funnel plots suggested no evidence of publication bias among studies. The results showed that compared to PE patients without OSA, the PE patients with moderate-severe OSA were more likely to be high-risk type (OR = 1.96, 95% CI [1.14, 3.34]) and with higher index of disease severity (sPESI: OR = 2.29, 95% CI [1.50, 3.47]; PAOI%: MD = 13.52, 95% CI [7.2, 19.83]). The prevalence of recurrent PE was higher in PE patients with OSA than those without OSA (RR = 3.87, 95% CI [1.65, 9.07]). However, there was no significant difference in right ventricle to left ventricle short-axis diameter (MD = 0.08, 95% CI [- 0.06, 0.21]), length of hospital stay (MD = 1.03, 95% CI [- 1.11, 3.17]), or prevalence of deep vein thrombosis (OR = 0.87, 95% CI [0.48, 1.57]). Sensitivity and subgroup analysis showed that the pooled outcomes were stable.

CONCLUSION

OSA, especially moderate-severe OSA, was a risk factor for high-risk PE and recurrent PE. However, the current evidence showed that the length of hospital stay is not influenced by OSA.

Acute pulmonary embolism in patients with obstructive sleep apnea: frequency, hospital outcomes, and recurrence

STUDY OBJECTIVES

The objectives of this study were to assess the effect of obstructive sleep apnea (OSA) on the risk of acute pulmonary embolism (PE), hospital outcomes including mortality, and PE recurrence.

METHODS

We retrospectively enrolled adult patients, admitted to Mayo Clinic Hospital in Rochester, Minnesota, within a 5-year period (2009-2013). We compared frequency of PE, hospital mortality, and secondary outcomes in patients with OSA versus patients without OSA. We assessed risk of PE recurrence in relation to compliance with OSA therapy.

RESULTS

Of 25,038 patients, 3,184 (13%) had OSA and 283 (1.1%) experienced PE. Frequency of PE in patients with and without OSA was 2.4% versus 0.9% (odds ratio [OR], 2.51; 95% confidence interval [CI], 1.9-3.3; P < .001). OSA was independently associated with increased risk of PE after adjusting for demographics and comorbidities (OR, 1.44; 95% CI, 1.07-1.9; P = .017). Adjusted hospital mortality was increased in patients with PE (OR, 2.88; 95% CI, 1.7-4.9; P < .001) but not in patients with OSA (OR, 0.98; 95% CI, 0.7-1.4, P = .92). OSA was not a significant determining factor for mortality in patients who experienced a PE (OR, 0.56; 95% CI, 0.1.1-2.78; P = .47), adjusting for demographics, PE severity, and Charlson comorbidity index. Adjusted risk of PE recurrence was greater in patients with OSA compared with patients without OSA (OR, 2.21; 95% CI, 1.05-4.68; P < .04). The patients compliant with OSA therapy had a lower rate of PE recurrence (16% vs 32%; P = not significant).

CONCLUSIONS

Although OSA significantly increases risk of acute PE occurrence and recurrences, related hospital mortality was not greater in patients with OSA compared with those without OSA. OSA therapy might have a modifying effect on PE recurrence.

Obstructive sleep apnea and venous thromboembolism: Overview of an emerging relationship

Obstructive sleep apnea (OSA) is a risk factor for cardiovascular syndromes. Venous thromboembolism (VTE) is a chronic disease, and pulmonary embolism (PE) is the major expression of VTE and the third most frequent cardiovascular disease. An increasing and emerging number of cross-sectional and longitudinal studies have linked OSA to VTE, and have postulated different putative pathways to explain how OSA might increase the risk of PE. We aim to provide a critical overview of the existing evidence about the complex relationship between these two conditions, with some factors and confounding variables still to be clarified. A global interpretation of the studies shows OSA is highly prevalent in VTE patients. This association represents a major public health burden, given the high prevalence and the mortality rates of both disorders. Although still not proven, OSA may induce a persistent hypercoagulable state that may contribute to increase VTE rate and its recurrence. Coagulant activity, platelet function and fibrinolytic system may improve after continuous positive airway pressure (CPAP) in OSA. However, there is a still a lack of randomized controlled trials to evaluate the potential of CPAP and/or extend oral anticoagulation to reduce PE incidence, recurrence and mortality by PE in patients with OSA.

Obstructive sleep apnea is associated with pulmonary artery thrombus load, disease severity, and survival in acute pulmonary embolism

INTRODUCTION

Obstructive sleep apnea (OSA) may have prothrombotic effects.

OBJECTIVE

To investigate the effect of OSA on disease severity, pulmonary artery thrombus load, and prognosis in patients with acute pulmonary embolism (PE).

METHODS

In 101 PE patients, disease severity was determined by the simplified PE severity index (sPESI) score, pulmonary artery thrombus load was quantified by the pulmonary artery obstruction index (PAOI), and sleep-disordered breathing was evaluated by nocturnal polygraphy.

RESULTS

Obstructive sleep apnea patients with an apnea-hypopnea index (AHI) ≥ 15/h cohort were significantly older (p < 0.001) and had significantly lower oxygen saturations (p = 0.008) when acute PE was diagnosed. The sPESI scores (p < 0.001), the PAOI (p = 0.005) and the N-terminal pro-brain-type natriuretic peptide (NT-proBNP) values (p = 0.009), were significantly higher in the AHI ≥ 15/h subgroup. In a multivariate regression analysis, the AHI remains a significant predictor for sPESI scores ≥ 1 (p = 0.003), increased NT-proBNP levels (p = 0.047), and elevated PAOI (p = 0.032). During the median follow-up time of 53 (interquartile range 38-70) months, all-cause and cardiovascular-related mortality was significantly higher in the AHI ≥ 15/h cohort (p = 0.004 and p = 0.015, respectively).

CONCLUSIONS

Obstructive sleep apnea is associated with pulmonary artery thrombus load, disease severity, and survival in acute PE possibly due to its prothrombotic effects.

Prevalence of obstructive sleep apnea in venous thromboembolism: a systematic review and meta-analysis

PURPOSE

Previous studies revealed that the concomitant prevalence of obstructive sleep apnea (OSA) and venous thromboembolism (VTE) was high, but the results were inconclusive due to various limitations. We aimed to systematically review the literature on the prevalence of OSA in patients with VTE.

METHODS

Relevant studies were identified on multiple electronic databases through July 2018. The DerSimonian-Laird random effects model was used to calculate the pooled prevalence of OSA, moderate-to-severe OSA, and severe OSA in VTE patients, respectively. Sensitivity analysis was performed based on diagnostic methods of OSA and races.

RESULTS

A total of 11 studies comprising 895 patients were available for the meta-analysis, but one study was excluded because of the between-study heterogeneity in the following analysis. The pooled prevalence of OSA, moderate-to-severe OSA, and severe OSA in VTE patients were 70% (95% CI = 65%, 75%), 41% (95% CI = 29%, 54%), and 19% (95% CI = 15%, 23%), respectively. Sensitivity analysis indicated that the prevalence was similar in different diagnostic methods, but the contributions of races to OSA were complex. Although the lower prevalence of all OSA and moderate-to-severe OSA as compared with Western countries, Asian countries have similar or even a little bit higher prevalence of severe OSA.

CONCLUSIONS

Findings from this meta-analysis supported that the prevalence of OSA in VTE patients was strikingly high. Screening for OSA in patients with VTE is necessary for developing effective treatment strategies.

Obstructive sleep apnoea and venous thromboembolism: pathophysiological links and clinical implications

Obstructive sleep apnoea (OSA) and pulmonary embolism (PE) remain major health issues worldwide. Data from pathophysiological studies suggest that both intermittent hypoxia and sleep fragmentation are associated with increased blood coagulability, endothelial dysfunction and venous stasis. There is growing evidence that OSA is potentially prevalent in and a risk factor for PE. Conversely, patients with acute PE have two to four times greater risk of moderate-to-severe OSA. The role of continuous positive airway pressure (CPAP) treatment in improving clinically meaningful outcomes in PE patients remains unclear, although some authors have suggested that CPAP could improve the hypercoagulability state and normalise circadian alterations in some of the coagulation molecules, as observed in patients with OSA. Emerging research highlights the complex interdependent relationships between OSA and PE, emphasising the need for rigorous, well-powered trials that address the impact of OSA and its treatment on the prevention and management of PE. Undoubtedly, these will require closer collaboration between the sleep medicine and clinical/venous thromboembolism communities.

Prothrombotic state in children with obstructive sleep apnea

OBJECTIVE

Increased blood coagulation might be one important mechanism linking obstructive sleep apnea (OSA) with cardiovascular diseases. We tested the association between several hemostatic parameters and sleep breathing-related variables in a representative pediatric population with a clinical suspicion of OSA.

METHODS

Polysomnography was performed in 152 snoring children to diagnose OSA. Anthropometric and clinical data were registered and venous blood samples were collected for the measurement of platelet count, plateletcrit, platelet distribution width (PDW), mean platelet volume (MPV), prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen and C-reactive protein.

RESULTS

Children with OSA had significantly higher platelet count, plateletcrit and PDW compared with those without OSA. After controlling for the anthropometric characteristics (age, gender, body mass index (BMI) z-score), platelet count negatively correlated with minimum SaO₂ while the plateletcrit correlated with time with SaO₂ <90% and MPV correlated with apnea-hypopnea index. PT and PT international normalized ratio correlated with mean SaO₂ and aPTT correlated with the oxygen desaturation index.

CONCLUSION

Our findings suggest that different OSA-related effects may be factors contributing to an enhanced coagulability in pediatric OSA. Measures reflecting apnea severity and disrupted sleep were associated with clotting factor changes independent of covariates affecting hemostatic function.

Obstructive sleep apnea in patients with chronic thromboembolic pulmonary hypertension

Background

Due to its effects, like an exaggerated negative intrathoracic pressure, sympathetic activation, systemic inflammation, oxidative stress, and endothelial dysfunction, obstructive sleep apnea (OSA) has been involved as a cause in multiple cardiovascular diseases. These diseases include coronary artery disease, hypertension, heart failure, and pulmonary hypertension (PH). Furthermore, OSA often coexists with chronic thromboembolic pulmonary hypertension (CTEPH) in clinical practice. However, few studies focus on OSA and its relationship with CTEPH. This study aims to determine whether OSA has an influence on the clinic status of patients with CTEPH, and to identify what possible factors are associated with OSA in CTEPH.

Methods

Patients who were newly diagnosed with CTEPH and received overnight polysomnography (PSG) monitoring from September 2015 to December 2017 were enrolled. OSA was defined as apnea-hypopnea index (AHI) of ≥5/h and the obstructive events at ≥50%. Baseline clinical characteristics and parameters were collected and compared between CTEPH patients with and without OSA. In addition, logistic regression analysis was performed to identify possible factors associated with OSA in CTEPH.

Results

Fifty-seven patients with CTEPH were eventually enrolled. Among them, 32 patients were diagnosed with OSA by PSG. CTEPH patients with OSA showed an older age, a higher body mass index (BMI), a higher hemoglobin level, a lower oxygen saturation and a worse World Health Organization functional class (WHO FC) (all P<0.05) when compared to CTEPH patients without OSA. In addition, sleep data including AHI, oxygen desaturation index and minimum oxygen saturation were also statistically different between two groups (all P<0.05). Adjusted for age, sex and BMI, hemoglobin [odd ratio (OR) =1.057, 95% confidence interval (CI): 1.001-1.117, P=0.046], oxygen saturation (OR =0.718, 95% CI: 0.554-0.929, P=0.012), N-terminal pro-brain natriuretic peptide (OR =1.001, 95% CI: 1.000-1.002, P=0.016), mean right atrium pressure (OR =1.284, 95% CI: 1.030-1.600, P=0.026), mean pulmonary arterial pressure (mPAP) (OR =1.087, 95% CI: 1.001-1.180, P=0.048), cardiac index (CI) (OR =0.058, 95% CI: 0.008-0.433, P=0.037), pulmonary vascular resistance (OR =1.004, 95% CI: 1.001-1.007, P=0.014) and WHO FC III-IV (OR =18.550, 95% CI: 2.363-144.128, P=0.005) were associated with OSA in CTEPH. Multivariate logistic regression analysis demonstrated CI (OR =0.051, 95% CI: 0.003-0.868, P=0.040) was independently associated with OSA in CTEPH in addition to age, sex and BMI.

Conclusions

OSA may aggravate the clinical status of CTEPH patients to some degree. In turn, a worse hemodynamics, oxygenation state and cardiac function are associated with OSA in CTEPH after being adjusted for age, sex and BMI. Among them, CI is the most important parameter in indicating the coexistence of OSA and CTEPH.

The secondary prevention of venous thromboembolism: Towards an individual therapeutic strategy

After the anticoagulant withdrawal, a substantial proportion of patients with venous thromboembolism will develop recurrent events. Whether to consider an extended treatment depends on the risk of recurrence and bleeding risk. The assessment of the individual risk profile remains a difficult task. Several basal and post-basal factors modulate the risk of recurrence and may help clinicians to select patients who can benefit from the extended therapy. During the year 2017, new evidence regarding the post-basal factors was provided by the Morgagni and Scope studies. Another interesting novelty was the VTE-BLEED score, the first bleeding risk score that obtained the external validation in venous thromboembolism setting. In secondary prevention, the use of direct oral anticoagulants is growing instead of vitamin K antagonist. Even at lower doses, direct oral anticoagulants showed to be effective and safe, to reduce all-cause mortality and seemed to be superior to placebo for the composite outcome of fatal bleeding and fatal recurrence. After the recently published Einstein-Choice trial, the role of aspirin has become truly marginal as rivaroxaban 10 mg showed a bleeding risk similar to aspirin 100 mg but a greater effectiveness reducing the relative risk of recurrence by about 70%. Another option for secondary prevention could be sulodexide, with a lower protective effect than direct oral anticoagulants but an interesting safety profile. In conclusion, in our opinion, an individual strategy taking into account the risk of recurrence, bleeding risk, therapeutic options and patient preferences is the most appropriate approach to secondary prevention of venous thromboembolism.