Obstructive Sleep Apnea and Smoking as a Risk Factor for Venous Thromboembolism Events: Review of the Literature on the Common Pathophysiological Mechanisms

No Genetic Causality between Tobacco Smoking and Venous Thromboembolism: A Two-Sample Mendelian Randomization Study

BACKGROUND

 Given the current debate in clinical research about the relationship between tobacco smoking and the risk of venous thromboembolism (VTE), a Mendelian randomization (MR) study was conducted aimed at elucidating the causal associations of current and past tobacco smoking with the risk of VTE, from the perspective of genetics.

METHODS

 Two-sample univariate and multivariable MR analyses were designed, using summary-level data from large genome-wide association studies involving European individuals. Causality was primarily assessed using multiplicative fixed-effects or random-effects model and inverse variance weighting, supplemented by MR-Egger regression, MR-PRESSO, Cochran's Q test, and leave-one-out for sensitivity analysis to test the reliability of the results.

RESULTS

 In the univariate MR analysis, no significant causal effects were found between current tobacco smoking and the risk of VTE, deep vein thrombosis (DVT), and pulmonary embolism (PE). Similarly, no significant causal effects were found between past smoking and VTE, DVT, and PE. As for the multivariable MR analysis, results were consistent with univariate MR analysis, with no significant causal effect of either current or past tobacco smoking on the risk of VTE, DVT, and PE.

CONCLUSION

 Evidence from both univariate and multivariable MR analyses demonstrated no significant causal relationships between current and past tobacco smoking and VTE, DVT, and PE. This contradicts positive correlations reported in some previous observational studies, which may be explained by other confounding factors. This provided genetic evidence for the conclusion reported in other observational studies that smoking did not affect VTE risk.

Association between changed self-rated health and the risk of venous thromboembolism in Malmö Preventive Program: a cohort study

Poor self-rated health (SRH) is associated with incident arterial cardiovascular disease in both sexes. Studies on the association between SRH and incident venous thromboembolism (VTE) show divergent results in women and no association in men. This study focuses on the association between change in SRH and incident VTE in a cohort of 11,558 men and 6682 women who underwent a baseline examination and assessment of SRH between 1974 and 1992 and a re-examination in 2002-2006. To investigate if changes in SRH over time affect the risk of incident VTE in men and women. During a follow-up time from the re-examination of more than 16 years, there was a lower risk for incident VTE among women if SRH changed from poor at baseline to very good/excellent (HR 0.46, 95% CI 0.28; 0.74) at the re-examination. Stable good SRH (good to very good/excellent at the re-examination, HR 0.60, 95% CI 0.42; 0.89), or change from good SRH at baseline into poor/fair at the re-examination (HR 0.68, 95% CI 0.51; 0.90) were all significantly associated with a reduced risk for VTE. All comparisons were done with the group with stable poor SRH. This pattern was not found among men. Regardless of a decreased or increased SRH during life, having an SRH of very good/excellent at any time point seems to be associated with a decreased risk of VTE among women.

Association between self-rated health and venous thromboembolism in Malmö Preventive Program: A cohort study

INTRODUCTION

Venous thromboembolism (VTE) and cardiovascular disease (CVD) share some risk factors such as smoking, obesity, and dietary habits. Poor self-rated health (SRH) has been shown to be a predictor of arterial CVD and mortality for both men and women. The association between SRH and VTE has only been investigated in one previous Swedish study with a cohort that just contained women. This Swedish study did not show any significant associations between poor SRH and VTE in women.

METHODS

A cohort of 22,444 men and 10,902 women in the Malmö Preventive Program was followed for a period of 44 years. All participants in the baseline screening with measurements including SRH were traced in national registers. Data on VTE events were collected from national hospital registries. Cox proportional regression analysis was used to calculate the association between SRH and time to VTE.

RESULTS

During a follow-up time of 44.31 years, a total of 2612 individuals were affected by VTE. Good SRH was associated with a lower risk for VTE in women both in the univariate model (HR = 0.75, CI = 0.65-0.85) and after adjustments for age, smoking, BMI and varicose veins (HR = 0.81, CI 0.70-0.93). SRH was not a predictor for VTE in men, neither in the unadjusted (HR = 1.05, CI 0.90-1.13) nor in the fully adjusted model (HR = 1.00, CI = 0.88-1.14).

CONCLUSION

In this cohort study, SRH was associated with VTE in women but not among men. The association was significant even when adjusting for well-known risk factors such as varicose veins, BMI and smoking.

The Effect of Obstructive Sleep Apnea on Venous Thromboembolism Risk in Patients Undergoing Total Joint Arthroplasty

Obstructive sleep apnea (OSA) is a known risk factor for venous thromboembolism (VTE), defined as pulmonary embolism (PE) or deep vein thrombosis (DVT); however, little is known about its effect on VTE rates after total joint arthroplasty (TJA). This study sought to determine whether patients with OSA who undergo TJA are at greater risk for developing VTE versus those without OSA.

Stroke in patients with secundum atrial septal defect and sequelae after transcatheter closure

OBJECTIVE

To evaluate the frequency of and risk factors for stroke as a presenting feature in adult patients with secundum atrial septal defect (ASD); rates of post-closure atrial fibrillation (AF) and stroke were also assessed.

METHODS

We retrospectively reviewed adult patients who presented with an ASD between 2002 and 2018, excluding those with known atrial arrhythmias. Risk factors for stroke were identified using multivariable logistic regression. Post-closure stroke was evaluated using survival analysis stratified by the presence of post-procedure AF.

RESULTS

Of 346 patients with ASD (median age 44 years), 34 (10%) presented with a history of stroke. Independent risk factors included elevated body mass index over 25 (OR: 18.2; 95% CI: 4.0 to 82.2; p<0.001), smoking (OR: 9.5; 95% CI: 3.8 to 23.9; p<0.001) and a prominent Eustachian valve (OR: 9.2; 95% CI: 3.4 to 25.2; p<0.001). A scoring system based on these three parameters provided robust stroke risk stratification. During a median follow-up of 12 months after closure, 12 patients (4%) experienced AF and 4 patients (1%) had a new stroke. AF was highly associated with development of stroke post-closure (p<0.001).

CONCLUSIONS

In this study population, the incidence of stroke prior to ASD closure among patients without atrial arrhythmias was 10%. Risk factors included obesity, smoking and prominent Eustachian valve anatomy. Lifestyle changes should be recommended for at-risk patients, and it may be reasonable to consider ASD closure in the absence of haemodynamic indications in patients at increased risk of stroke.

[The role of biomarkers in the detection of the OSA syndrome. A narrative review of the literature]

INTRODUCTION

Obstructive sleep apnoea (OSA) is a common sleep-related breath disorder associated with cardiovascular and cerebrovascular complications, such as hypertension, arrhythmia, coronary artery disease and stroke. Unfortunately, OSA is underdiagnosed.

BACKGROUND

Because of its clinical and therapeutic variability, OSA could benefit a personalized medicine approach. Diagnosis with polysomnography is expensive and access is limited. Clinical scoring systems allow screening of OSA, but many limitations exist. Because of this, biomarkers could be useful for the detection of OSA.

OUTLOOK

Biomarkers specific to OSA would allow for better mass screening and more personalized treatment of the disease. This narrative review of the literature aims to summarize the biomarkers already described for the diagnosis of OSA and clarify both their advantages and limitations in daily practice.

CONCLUSIONS

Our review of the literature did not actually identify an ideal biomarker even if promising research is ongoing.

Mitochondria-DNA copy-number and incident venous thromboembolism among middle-aged women: a population-based cohort study

Venous thromboembolism (VTE) is the third most common cardiovascular disease. Low amount of mitochondrial DNA copy number (mtDNA-CN) has been associated with arterial cardiovascular disease (CVD) and reflects mitochondrial dysfunctions. However, whether mtDNA-CN is associated with VTE has not been determined. To examine the association between mtDNA-CN and incident VTE among middle-aged women. 6917 women aged 50-64 years, followed for 20 years in the Women's Health In the Lund Area (WHILA) study. DNA samples for mtDNA quantification were available from 2521 women. Quantification of mtDNA-CN was performed using a well-optimized droplet digital PCR method. After exclusions of women with anticoagulant treatment, women living in nursing homes, and women who were diagnosed with cancer, stroke, VTE, or coronary heart disease at baseline, a cohort of 2117 women remained for analysis. Cox regression was used to analyze the relationship between mtDNA-CN and time to VTE (hazard ratio = HR). In total, 87 women were diagnosed with VTE during follow-up, corresponding to an incidence rate of 2.8 per 1000 person-years. Neither crude nor adjusted HR for mtDNA-CN were significantly associated with incident VTE. A sensitivity analysis with inclusion of excluded women did not change the results. MtDNA-CN was not significantly associated with VTE. The present study suggests that mtDNA-CN, reflecting mitochondrial dysfunction, should not be considered a biomarker that plays a major role for developing VTE. However, due to limited study size we may not exclude minor associations.

Prevalence and characteristics of venous thromboembolism in severe exacerbation of chronic obstructive pulmonary disease in a tertiary care hospital in India

Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) carries a high risk of venous thromboembolism (VTE). Pulmonary embolism (PE) and AECOPD increase the mortality and morbidity risk associated with each other. Racial and ethnic differences in VTE risk have been documented in multiple studies. However, there is a dearth of reliable Indian data on the same. This study was planned to find the prevalence of VTE in the setting of severe AECOPD in a tertiary care hospital in India and to identify the clinical, laboratory and radiological characteristics of VTE in severe AECOPD. A total of 156 consecutive patients admitted with severe AECOPD and meeting the specified inclusion and exclusion criteria were recruited. Thorough workup of all patients was done including ABG, serum D dimer, ECG, compression ultrasound of lower limbs and 2-D echocardiography. Patients with high pre-test probability score, or intermediate pre-test probability score at presentation with serum D dimer above the age adjusted cut-off underwent computerised tomography pulmonary angiography (CTPA).  Results were analysed using SPSS version 23.  Sixteen (10.3%) patients had VTE, 15 (93.75%) of them being cases of isolated PE. Female gender, higher cumulative past exposure to corticosteroid, higher alveolar-arterial gradient, right ventricular dysfunction, and higher mean pulmonary artery pressure were associated with increased risk for VTE. The prevalence of VTE in AECOPD in this study among an Indian population is higher than among other Asians, but lower than among the Blacks, the Caucasians and the Middle-East ethnicities. Since a vast majority of VTE presents as PE without DVT in the setting of AECOPD, the absence of deep vein thrombosis of lower limbs does not rule PE in the setting.

Self-rated health and venous thromboembolism among middle-aged women: a population-based cohort study

Venous thromboembolism (VTE) is one of the most common types of cardiovascular diseases (CVDs) and is associated with increased mortality-risk. Poor-self rated health (SHR) has been associated with elevated inflammatory markers and CVDs. However, little is known about as a predictor of incident VTE. To examine the association between self-rated health, lifestyle and incident VTE among middle-aged women. 6917 women aged 50–64 years, followed for 20 years in the Women’s Health In the Lund Area (WHILA) study. After exclusion of those who medicated with anticoagulants, were living in nursing homes or suffered from cancer, stroke, VTE or CHD before baseline, a cohort of 5626 women remained. Cox regression was used to analyse the relationship between self-rated health and time to VTE, censored for any of the previous mentioned diseases during follow-up. Data were collected by questionnaires, physical examinations and Swedish registers. In total, 220 women were affected by VTE corresponding to an incidence rate of 3.9 per 1000 person-years. Adjustment for self-rated health did not significantly predict incident VTE, and neither did any of the lifestyle-related habits (e.g. physical activity and dietary habits including alcohol consumption), besides smoking. This study supports previous results with varicose veins and waist circumference as strong predictors of VTE. Poor self-rated health does not seem to be a valid predictor of VTE. Among lifestyle-related parameters, smoking was significantly associated with risk of VTE. We could also confirm the effect of the other already known risk factors.

Evaluation of stability of deep venous thrombosis of the lower extremities using Doppler ultrasound

Objective

This study aimed to assess using Doppler ultrasound for analyzing stability of deep venous thrombosis (DVT) of the lower extremities.

Methods

Patients with DVT of the lower extremities who were treated from August 2017 to December 2019 were selected. The patients were divided into stable and unstable groups according to whether thrombus was collected in a filter. Related ultrasound and blood test results were analyzed and compared.

Results

A total of 126 patients with DVT of the lower extremities were included, of whom 74 were in the stable group and 52 were in the unstable group. There were significant differences in the prothrombin time (PT), and lipoprotein alpha, D-dimer, and triglyceride levels between the groups. D-dimer levels >2800 ug/L, smoking, history of venous thrombosis, PT >13.15 s, and body mass index >24.45 kg/m² were independent risk factors for stability of DVT of the lower extremities. The area under the curve with combined detection of DVT was significantly higher than that for body mass index, PT, and D-dimer alone.

Conclusion

Doppler ultrasound may be reliable for analyzing the stability of DVT of the lower extremities. Related strategies targeting risk factors are required for reducing DVT of the lower extremities.

Updated clinical models for VTE prediction in hospitalized medical patients

Venous thromboembolism (VTE) occurring in hospitalized medical patients is associated with increased length of hospitalization, high rate of acute care hospital transfer, longer inpatient rehabilitation and multiplication of health-care costs. Identification of acutely ill hospitalized medical patients eligible for thromboprophylaxis is a sophisticated process. Global VTE risk stems from the combination of predictors related with the acute medical illness, comorbidities, associated treatments and patients' intrinsic risk factors. Emerging clinical risk factors related to underlying pathologies should be considered when VTE risk is assessed. The Padua Prediction Score (PPS), the International Medical Prevention Registry on Venous Thromboembolism (IMPROVE-RAM) and the Geneva Risk Score are three robust risk assessment models (RAM) which underwent extensive external validation in cohorts of acutely ill hospitalized medical patients. The development of the IMPROVE bleeding risk assessment model and the identification of D-Dimer increase as a biomarker-predictor of VTE are some steps forward for personalized thromboprophylaxis. The beneficial impact of the RAMs in VTE prevention is already seen by the decrease of in-hospital VTE rates when RAMs are incorporated in electronic alert systems.

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.

Comparison of clinical scores in their ability to detect hypoxemic severe OSA patients

BACKGROUND

Severe obstructive sleep apnea (sOSA) and preoperative hypoxemia are risk factors of postoperative complications. Patients exhibiting the combination of both factors are probably at higher perioperative risk. Four scores (STOP-Bang, P-SAP, OSA50, and DES-OSA) are currently used to detect OSA patients preoperatively. This study compared their ability to specifically detect hypoxemic sOSA patients.

METHODS

One hundred and fifty-nine patients scheduled for an overnight polysomnography (PSG) were prospectively enrolled. The ability of the four scores to predict the occurrence of hypoxemic episodes in sOSA patients was compared using sensitivity (Se), specificity (Sp), Youden Index, Cohen kappa coefficient, and the area under ROC curve (AUROC) analyses.

RESULTS

OSA50 elicited the highest Se [95% CI] at detecting hypoxemic sOSA patients (1 [0.89-1]) and was significantly more sensitive than STOP-Bang in that respect. DES-OSA was significantly more specific (0.58 [0.49-0.66]) than the three other scores. The Youden Index of DES-OSA (1.45 [1.33-1.58]) was significantly higher than those of STOP-Bang, P-SAP, and OSA50. The AUROC of DES-OSA (0.8 [0.71-0.89]) was significantly the largest. The highest Kappa value was obtained for DES-OSA (0.33 [0.21-0.45]) and was significantly higher than those of STOP-Bang, and OSA50.

CONCLUSIONS

In our population, DES-OSA appears to be more effective than the three other scores to specifically detect hypoxemic sOSA patients. However prospective studies are needed to confirm these findings in a perioperative setting.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov: NCT02050685.

Impact of obstructive sleep apnea in transsphenoidal pituitary surgery: An analysis of inpatient data

OBJECTIVES/HYPOTHESIS

Although previous studies have reported increased perioperative complications among obstructive sleep apnea (OSA) patients undergoing any surgery requiring general anesthesia, there is a paucity of literature addressing the impact of OSA on postoperative transsphenoidal surgery (TSS) complications. The aim of this study was to analyze postoperative outcomes in transsphenoidal pituitary surgery patients with OSA. Secondarily, we examined patient characteristics and comorbidities.

STUDY DESIGN

Retrospective analysis.

METHODS

The 2002 to 2013 National Inpatient Sample was queried for patients undergoing TSS for pituitary neoplasm. Patients with an additional diagnosis of OSA were identified, and compared to a non-OSA cohort.

RESULTS

There were 17,777 patients identified; 5.0% (N = 889) had an additional diagnosis of OSA. The OSA cohort had more comorbidities including diabetes mellitus, congestive heart failure, chronic pulmonary disease, coagulopathy, hypertension, hypothyroidism, liver disease, obesity, peripheral vascular disease, renal failure, acromegaly, and Cushing's syndrome. Postoperatively, OSA was independently associated with increased risks of tracheostomy (P = .015) and hypoxemia (P < .001), and decreased risk of cardiac complications (P = .034). OSA patients did not have increased rates of cerebrospinal fluid rhinorrhea, diabetes insipidus, reintubation, aspiration pneumonia, infectious pneumonia, thromboembolic complications, or urinary/renal complications. In-hospital mortality rates did not vary between the two cohorts.

CONCLUSIONS

In patients who underwent transsphenoidal pituitary surgery, OSA was associated with higher rates of certain pulmonary and airway complications. OSA was not associated with increased non-pulmonary/airway complications or inpatient mortality, despite older average age and higher comorbidity rates.

LEVEL OF EVIDENCE

2C. Laryngoscope, 128:1027-1032, 2018.

Incidence and Risk Factors of Postoperative Hematoma Requiring Reoperation in Single-level Lumbar Fusion Surgery

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

The purpose of the present study was to examine the incidence and risk factors for postoperative hematoma requiring reoperation in patients undergoing single-level lumbar fusion surgery.

SUMMARY OF BACKGROUND DATA

Postoperative hematoma can cause devastating neurological consequences after spine surgery. Risk factors for hematoma in specific spine procedures have not been well established.

METHODS

A cohort of patients undergoing single-level lumbar fusion surgery was constructed from the 2012 to 2013 American College of Surgeons National Surgical Quality Improvement Program dataset using Current Procedural Terminology codes (22533, 22558, 22612, 22630, and 22633). In cases requiring reoperation within 30 days after initial surgery, postoperative hematoma was identified using the ICD-9 code 998.1. Risk factors for postoperative hematoma were assessed with logistic regression modeling.

RESULTS

Of 5280 patients undergoing single-level lumbar fusion surgery, 27 patients (0.5%) developed a postoperative hematoma requiring reoperation for hematoma evacuation. A heightened incidence of postoperative hematoma was found in patients who were smokers (1.0% vs. 0.4% for nonsmokers, P = 0.016) or who had a diagnosis of bleeding disorder (3.8% vs. 0.5% for those without bleeding disorder, P = 0.007). Multivariate logistic regression analysis indicated that the adjusted odds ratios for postoperative hematoma associated with smoking and bleeding disorder were 3.34 (95% confidence interval, 1.15-9.71) and 10.2 (95% confidence interval, 1.9-54.8), respectively.

CONCLUSION

Smoking and bleeding disorder appear to be major risk factors for postoperative hematoma requiring reoperation after single-level lumbar fusion surgery. Intervention programs targeting patients with these risk factors are needed to reduce their excess risk of postoperative hematoma.

LEVEL OF EVIDENCE

3.