Epidemiological updates of venous thromboembolism in a Chinese population

Prevalence and risk factors of hospital acquired venous thromboembolism

OBJECTIVES

To investigate the prevalence, clinical characteristics and risk factors of hospital acquired venous thromboembolism (HA-VTE) in a Chinese Hospital.

METHODS

Retrospective analysis of patients diagnosed as HA-VTE in a single institution from January 2016 to December 2022 was performed. Patients with VTE prior to admission or within 48 h after admission were excluded. Demographic data of patients was retrieved from the electronic medical database, and parameters affecting the occurrence of HA-VTE were analyzed.

RESULTS

4,022 patients from 321,997 episodes of medical admissions were diagnosed as VTE. Among these, 952 (23.7%) fulfilled the criteria of HA-VTE, corresponding to an incidence of 0.296%. 76% of patients presented with HA-deep vein thrombosis (DVT) alone, 13% presented with isolated HA-pulmonary embolism (PE), and 11% presented with concomitant HA- DVT and PE. Risk factor analyses showed statistically higher incidence in patients with elder age (67.5 ± 15.5 vs 48.3 ± 17.2 years, p < .001), male gender (0.346% vs 0.262%, p < .001), malignancy (0.513% vs 0.252%, p < .001), trauma (0.659% vs 0.28%, p < .001), emergency admission (0.664% vs 0.186%, p < .001), ICU stay (2.981% vs 0.226%, p < .001), and patients undergoing major surgery (0.702% vs 0.176%, p < .001). Patients with HA-VTE had longer hospital stay (22.5 ± 26.6 vs 7.21 ± 9.23 days, p < .001) and higher mortality rate (8.51% vs 1.01%, p < .001). The crude incidence rate of HA-VTE increased annually from 0.75 per 1,000 patients in 2016 to 5.89 per 1,000 patients in 2022. The subspecialties with the highest incidence rate of HA-VTE were cardiovascular surgery (1.40%), neurosurgery (1.10%), and respiratory medicine (0.72%).

CONCLUSION

This is one of the few large scale studies to show that HA-VTE, accounting for nearly one quarter of all VTE events, occurs in 0.296% of adult hospitalizations. Patients with elder age, malignancy, ICU stay, and undergoing major surgery require more intensive HA-VTE surveillance and prevention.

Identification of key risk factors for venous thromboembolism in urological inpatients based on the Caprini scale and interpretable machine learning methods

PURPOSE

To identify the key risk factors for venous thromboembolism (VTE) in urological inpatients based on the Caprini scale using an interpretable machine learning method.

METHODS

VTE risk data of urological inpatients were obtained based on the Caprini scale in the case hospital. Based on the data, the Boruta method was used to further select the key variables from the 37 variables in the Caprini scale. Furthermore, decision rules corresponding to each risk level were generated using the rough set (RS) method. Finally, random forest (RF), support vector machine (SVM), and backpropagation artificial neural network (BPANN) were used to verify the data accuracy and were compared with the RS method.

RESULTS

Following the screening, the key risk factors for VTE in urology were "(C1) Age," "(C2) Minor Surgery planned," "(C3) Obesity (BMI > 25)," "(C8) Varicose veins," "(C9) Sepsis (< 1 month)," (C10) "Serious lung disease incl. pneumonia (< 1month) " (C11) COPD," "(C16) Other risk," "(C18) Major surgery (> 45 min)," "(C19) Laparoscopic surgery (> 45 min)," "(C20) Patient confined to bed (> 72 h)," "(C18) Malignancy (present or previous)," "(C23) Central venous access," "(C31) History of DVT/PE," "(C32) Other congenital or acquired thrombophilia," and "(C34) Stroke (< 1 month." According to the decision rules of different risk levels obtained using the RS method, "(C1) Age," "(C18) Major surgery (> 45 minutes)," and "(C21) Malignancy (present or previous)" were the main factors influencing mid- and high-risk levels, and some suggestions on VTE prevention were indicated based on these three factors. The average accuracies of the RS, RF, SVM, and BPANN models were 79.5%, 87.9%, 92.6%, and 97.2%, respectively. In addition, BPANN had the highest accuracy, recall, F1-score, and precision.

CONCLUSIONS

The RS model achieved poorer accuracy than the other three common machine learning models. However, the RS model provides strong interpretability and allows for the identification of high-risk factors and decision rules influencing high-risk assessments of VTE in urology. This transparency is very important for clinicians in the risk assessment process.

Prevalence and risk factors of deep venous thrombosis of hospitalizations in plateau: a cross-section analysis

BACKGROUND

Deep venous thrombosis (DVT) is a serious public health issue that threatens human health and economic development. Presently, differences in the prevalence of DVT among individuals from different nationalities, residents of high-altitude areas, and those consuming any special diet are unknown. Therefore, we aimed to elucidate the prevalence of and the associated risk factors for DVT in hospitalized patients in the plateau areas.

METHODS

The subjects were hospitalized patients in three grade III-a hospitals in the Qinghai Province, China, during January-October 2020. The demographic, clinical, and laboratory data were collected at admission, and ultrasonography of the bilateral lower extremities was performed. The hospital stay-duration was recorded at the time of discharge.

RESULTS

A total of 3432 patients were enrolled, of which 159 (4.60%) were diagnosed with DVT. The age of > 50 years (OR = 2.434, 95% CI: 1.521-3.894252, P < 0.001), residence altitude of ≥ 3000 m (OR = 2.346, 95% CI: 1.239-4.440, P = 0.009), D-dimer level of ≥ 0.5 mg/L (OR = 2.211, 95% CI: 1.547-3.161, P < 0.001), presence of comorbidities (OR = 1.904, 95% CI: 1.386-2.705, P < 0.001), a history of varicose veins (OR = 1.990, 95% CI: 0.959-4.128, P = 0.045), and current medications (OR = 2.484, 95% CI: 1.778-3.471, P < 0.001) were identified as risk factors for DVT in these plateau areas.

CONCLUSION

The prevalence of DVT in the hospitalized patients of the studied plateau areas was 4.60%. We recommend considering individualized risk stratification (age > 50 years, residence altitude ≥ 3000 m, a history of varicose veins, D-dimer level ≥ 0.5 mg/L, current medications, and comorbidities) for patients at the time of admission.

Venous thromboembolism among Asian populations with localized colorectal cancer undergoing curative resection: is pharmacological thromboprophylaxis required? A systematic review and meta-analysis

PURPOSE

We compared the incidence of venous thromboembolism (VTE) among Asian populations with localized colorectal cancer undergoing curative resection with and without the use of pharmacological thromboprophylaxis (PTP).

METHODS

A comprehensive literature search was undertaken to identify relevant studies published from January 1, 1980 to February 28, 2022. The inclusion criteria were patients who underwent primary tumor resection for localized nonmetastatic colorectal cancer; an Asian population or studies conducted in an Asian country; randomized controlled trials, case-control studies, or cohort studies; and the incidence of symptomatic VTE, deep vein thrombosis, and/or pulmonary embolism as the primary study outcomes. Data were pooled using a random-effects model. This study was registered in PROSPERO on October 11, 2020 (No. CRD42020206793).

RESULTS

Seven studies (2 randomized controlled trials and 5 observational cohort studies) were included, encompassing 5,302 patients. The overall incidence of VTE was 1.4%. The use of PTP did not significantly reduce overall VTE incidence: 1.1% (95% confidence interval [CI], 0%-3.1%) versus 1.9% (95% CI, 0.3%-4.4%; P = 0.55). Similarly, PTP was not associated with significantly lower rates of symptomatic VTE, proximal deep vein thrombosis, or pulmonary embolism.

CONCLUSION

The benefit of PTP in reducing VTE incidence among Asian patients undergoing curative resection for localized colorectal cancer has not been clearly established. The decision to administer PTP should be evaluated on a case-bycase basis and with consideration of associated bleeding risks.

Under the dual effect of inflammation and pulmonary fibrosis, CTD-ILD patients possess a greater susceptibility to VTE

As an autoimmune disease, the persistent systemic inflammatory response associated with connective tissue disease (CTD) is involved in the development of venous thromboembolism (VTE). However, clinical data showed that the risk of VTE in patients differed between subtypes of CTD, suggesting that different subtypes may have independent mechanisms to promote the development of VTE, but the specific mechanism lacks sufficient research at present. The development of pulmonary fibrosis also contributes to the development of VTE, and therefore, patients with CTD-associated interstitial lung disease (CTD-ILD) may be at higher risk of VTE than patients with CTD alone or patients with ILD alone. In addition, the activation of the coagulation cascade response will drive further progression of the patient's pre-existing pulmonary fibrosis, which will continue to increase the patient's risk of VTE and adversely affect prognosis. Currently, the treatment for CTD-ILD is mainly immunosuppressive and antirheumatic therapy, such as the use of glucocorticoids and janus kinase-inhibitors (JAKis), but, paradoxically, these drugs are also involved in the formation of patients' coagulation tendency, making the clinical treatment of CTD-ILD patients with a higher risk of developing VTE challenging. In this article, we review the potential risk factors and related mechanisms for the development of VTE in CTD-ILD patients to provide a reference for clinical treatment and prevention.

Ophthalmic nurses' knowledge, attitude, and practice toward venous thromboembolic prevention: a dual-center cross-sectional survey

Background

Venous thromboembolism (VTE) is a severe preventable complication among ophthalmic surgical patients. The knowledge, attitude, and practice (KAP) of nurses play a key role in effective VTE prevention. However, little is known about the KAP of ophthalmic nurses' VTE prevention. This study aimed to examine the level of KAP toward VTE prevention among Chinese ophthalmic nurses and to investigate the influencing factors of their VTE practice.

Methods

A total of 610 ophthalmic nurses from 17 cities in Hunan and Zhejiang Provinces, China, participated in this study. Data was collected via the Sojump online platform from March to April 2021. A self-administered VTE questionnaire was developed to assess nurses' KAP toward VTE prevention. Multiple linear regression analysis was used to analyze the influencing factors of ophthalmic nurses' VTE prevention practice.

Results

The scores (correct rates) of ophthalmic nurses' knowledge, attitude, and practice were 103.87 ± 20.50 (76.4%), 21.96 ± 2.72, and 48.96 ± 11.23 (81.6%), respectively. The three lowest-scored knowledge items were related to VTE complications, physical prevention, and risk assessment. The three lowest-scored attitude items were related to nurses' training, VTE risk, and patient education. The three lowest-scored practice items were related to the assessment scale, VTE assessment, and patient education. Nurses' knowledge, attitude, and practice were significantly correlated with each other. Multiple linear regression analysis showed that Hunan Province (B = 2.77, p = 0.006), general hospital (B = 2.97, p = 0.009), outpatient department (B = 3.93, p = 0.021), inpatient department (B = 2.50, p = 0.001), previous VTE prevention training (B = 3.46, p < 0.001), VTE prevention management in hospital (B = 4.93, p < 0.001), better knowledge (B = 0.04, p = 0.038), and positive attitude towards VTE prevention (B = 1.35, p < 0.001) were all significantly and positively associated with higher practice scores in VTE prevention.

Conclusions

Our study provided a comprehensive understanding of the ophthalmic nurses' knowledge, attitude, and practice in VTE prevention, as well as identified specific items in each dimension for improvement. In addition, our study showed multiple factors were associated with ophthalmic nurses' practice in VTE prevention, including environmental factors, training and management, knowledge and attitudes toward VTE prevention. Our findings provide important implications and guidance for future intervention programs to improve the ophthalmic nurses' knowledge, attitude, and practice in VTE prevention.

The effect of low molecular weight heparin combined with air pressure in the prevention of lower extremity venous thrombosis after cesarean section: A single-center retrospective study

In this study, we investigated the effect of low-molecular-weight heparin combined with pneumatic pressure in preventing lower extremity deep vein thrombosis after cesarean section, as well as on the visual analog scale (VAS) score. 120 women who underwent cesarean sections at full term in our hospital from January 2019 to January 2022 were included and divided into a control group (55 cases) and an observation group (65 cases) based on the different treatment methods: the control group was treated with low-molecular-weight heparin and the observation group was treated with pneumatic compression therapy based on the control group. The 2 groups were analyzed for thrombosis, clinical efficacy of the treatment methods, and VAS scores. The incidence of deep vein thrombosis in the observation group were significantly lower than in the control group (4.62% vs 21.82%, P < .05). There were no statistically significant differences in activated partial thromboplastin time, prothrombin time, and thrombin time between the 2 groups (P > .05) before treatment; however, after treatment, activated partial thromboplastin time, prothrombin time, and thrombin time in the observation group were significantly higher than those in the control group (P < .05). The clinical efficacy was significantly higher in the observation group compared with the control group (95.38% vs 78.18%, respectively). The VAS scores in the observation group were significantly lower than those in the control group (P < .05). Hence, low-molecular-weight heparin combined with pneumatic pressure therapy significantly reduces the incidence of lower limb deep vein thrombosis after cesarean section. It also improves the coagulation index and reduces post-operative pain. Therefore, it should be considered for use in clinical practice.

Venous thromboembolism: Why is it still a significant health problem?

BACKGROUND

Venous thromboembolism (VTE) remains the third leading cause of acute cardiovascular syndrome following myocardial infarction and ischemic stroke. The global burden of disease worldwide is high and shows a steady upward trend in recent years with an incidence of 1-2 per 1000 adults per year. The overarching goal of the initial management of VTE is to prevent early and late adverse outcomes. Rapid evaluation and therapeutic intervention is vital to improving prognosis.

METHODS

We searched PubMed, Science Direct and Scopus databases for articles published in the last 10 years. Additionally, some earlier articles were analyzed.

RESULTS

For the purposes of this review, we discussed how understanding the epidemiology of VTE and the current knowledge of early and late complications of this disease have shaped the current approach to VTE prevention. We also analyzed the current knowledge and the most up-to-date information about VTE in COVID-19 infection. Contemporary perspective presented in this article on mortality in VTE, the incidence of recurrences, the risk of major bleeding during therapy and the chronic complications indicate why this is a major challenge for today's medicine and a current target for further research.

CONCLUSIONS

Understanding the interaction between environmental and genetic factors appears to be crucial in the diagnostic process. It can provide insight into the pathophysiology of VTE, potentially identifying options for targeted prevention and treatment. However, due to differences in clinical presentation, diagnosing pulmonary embolism may not be an easy task which perfectly illustrates the scale and complexity of the disease.

Economic Evaluation of Direct Oral Anticoagulants Compared to Warfarin for Venous Thromboembolism in Thailand: A Cost-Utility Analysis

BACKGROUND

Direct oral anticoagulants (DOACs) have been used for venous thromboembolism (VTE) in Thailand. However, they have not been listed in the National List of Essential Medicines (NLEM). A cost-effectiveness analysis is needed to aid policymakers in deciding whether DOACs should be listed in the NLEM. This study aimed to assess the cost-effectiveness of DOACs for patients with VTE in Thailand.

METHODS

A cohort-based state transition model was constructed from a societal perspective with a lifetime horizon. All available DOACs, including apixaban, rivaroxaban, edoxaban, and dabigatran, were compared with warfarin. A 6-month cycle length was used to capture all costs and health outcomes. The model consisted of nine health states, including VTE on treatment, VTE off treatment, recurrent VTE, clinically relevant non-major bleeding, gastrointestinal bleeding, intracranial bleeding, post-intracranial bleeding, chronic thromboembolic pulmonary hypertension, and death. All inputs were based on a comprehensive literature review. The model outcomes included total cost and quality-adjusted life-years (QALYs) with a 3% annual discount rate. A fully incremental cost-effectiveness analysis and the incremental cost-effectiveness ratio (ICER) per QALY gained were calculated at a willingness-to-pay (WTP) of THB 160,000/QALY ($5003). The robustness of the findings was assessed using deterministic and probabilistic sensitivity analyses.

RESULTS

All DOACs were associated with a decreased risk of VTE recurrence and intracranial hemorrhage. In the base-case analysis, apixaban could increase 0.16 QALYs compared with warfarin. An ICER for apixaban was 269,809 Thai baht (THB)/QALY ($8437/QALY). Rivaroxaban had a better QALY than warfarin at 0.09 QALYs with an ICER of 757,363 THB/QALY ($23,682/QALY). Edoxaban and dabigatran could also increase by 0.10 QALYs with an ICER of 709,945 THB ($22,200) and 707,145 THB ($22,122)/QALY, respectively. Our probabilistic sensitivity analyses indicated that warfarin had a 99.8% possibility of being cost-effective, while apixaban had a 0.2% possibility of being cost-effective at the current WTP. Other DOACs had no possibility of being cost-effective.

CONCLUSIONS

All DOACs were not cost-effective for VTE treatment at the current WTP in Thailand. Apixaban is likely to be the best option among DOACs.

Automatic detection of pulmonary embolism in computed tomography pulmonary angiography using Scaled-YOLOv4

BACKGROUND

Pulmonary embolism (PE) is a common but fatal clinical condition and the gold standard of diagnosis is computed tomography pulmonary angiography (CTPA). Prompt diagnosis and rapid treatment can dramatically reduce mortality in patients. However, the diagnosis of PE is often delayed and missed.

METHODS

In this study, we identified a deep learning model Scaled-YOLOv4 that enables end-to-end automated detection of PE to help solve these problems. A total of 307 CTPA data (Tianjin 142 cases, Linyi 133 cases, and FUMPE 32 cases) were included in this study. The Tianjin dataset was divided 10 times in the ratio of training set: validation set: test set = 7:2:1 for model tuning, and both the Linyi and FUMPE datasets were used as independent external test sets to evaluate the generalization of the model.

RESULTS

Scaled-YOLOv4 was able to process one patient in average 3.55 s [95% CI: 3.51-3.59 s]. It also achieved an average precision (AP) of 83.04 [95% CI: 79.36-86.72] for PE detection on the Tianjin test set, and 75.86 [95% CI: 75.48-76.24] and 72.74 [95% CI: 72.10-73.38] on Linyi and FUMPE, respectively.

CONCLUSIONS

This deep learning algorithm helps detect PE in real time, providing radiologists with aided diagnostic evidence without increasing their workload, and can effectively reduce the probability of delayed patient diagnosis.

Population-Based Clinical Studies Using Routinely Collected Data in Hong Kong, China: A Systematic Review of Trends and Established Local Practices

Background: Routinely collected health data are increasingly used in clinical research. No study has systematically reviewed the temporal trends in the number of publications and analyzed different aspects of local research practices and their variations in Hong Kong, China, with a specific focus on research ethics governance and approval.

Methods: PubMed was systematically searched from its inception to March 28, 2023, for studies using routinely collected healthcare data from Hong Kong.

Results: A total of 454 studies were included. Between 2000 and 2009, 32 studies were identified. The number of publications increased from 5 to 120 between 2010 and 2022. Of the investigator-led studies using the Hospital Authority (HA)’s cross-cluster data (n = 393), 327 (83.2%) reported receiving ethics approval from a single cluster/university-based REC, whereas 50 studies (12.7%) did not report approval from a REC. For use of the HA Data Collaboration Lab, approval by a single hospital-based or University-based REC is accepted. Repeated submission of identical ethics applications to different RECs is estimated to cost HK$4.2 million yearly.

Conclusions: Most studies reported gaining approval from a single cluster REC before retrieval of cross-cluster HA data. Substantial cost savings would result if repeated review of identical ethics applications were not required.

Risk factors and potential predictors of pulmonary embolism in cancer patients undergoing thoracic and abdominopelvic surgery: a case control study

BACKGROUND

Postoperative pulmonary embolism (PE) is a severe complication leading to death and poor prognosis. The present study investigated the risk factors and potential predictors of PE in cancer patients undergoing thoracic and abdominopelvic surgery.

METHODS

A retrospective study was conducted on the patients with cancer who underwent thoracic and abdominopelvic surgery in Sichuan Cancer Hospital from December 2016 to January 2022. A total of 189 patients were included, in which 63 patients diagnosed PE after operation were collected as PE group, and 126 patients matched by age, type of cancer and cancer location were enrolled as control group. Conditional logistic regression was conducted to analyze the association between PE and risk factors. Predictive values of key factors were compared by the area under the curve (AUC) in receiver operating characteristic curve (ROC) curve.

RESULTS

Conditional multivariate logistic regression showed that BMI (odds ratio [OR] 4.065, 95% confidence interval [CI] 1.138-14.527; p = 0.031), intraoperative hypotension time (OR 4.095, 95% CI 1.367-12.266; p = 0.009), same day fluid balance (OR 0.245, 95% CI 0.061-0.684; p = 0.048), and postoperative D-Dimer (OR 1.693, 95% CI 1.098-2.611; p = 0.017) were significantly related to the occurrence of postoperative PE. Postoperative D-Dimer had the maximal AUC value 0.8014 (95% CI: 0.7260-0.8770) for predicting PE, with a cutoff value of 1.505 μg/ml.

CONCLUSIONS

BMI, intraoperative hypotension time, lower same day fluid balance and postoperative D-dimer are independent risk factors associated with PE in cancer patients undergoing thoracic and abdominopelvic surgery. Postoperative D-Dimer seems to be a good indicator to predict postoperative PE for cancer patients.

Incidence of Venous Thromboembolism: The 3rd Korean Nationwide Study

BACKGROUND

The incidence of venous thromboembolism (VTE) has gradually increased in the Korean population. This study aimed to evaluate the annual age- and sex-adjusted incidence rates (ASR) of VTE and anticoagulation trends between 2014 and 2018.

METHODS

Using the Korean Health Insurance Review and Assessment Service database, we retrospectively identified VTE patients between 2014 and 2018 using both diagnostic and medication anticoagulant codes assigned within 6 months of the initial index event. Anticoagulant patterns were classified as follows: direct oral anticoagulants (DOAC), parenteral anticoagulants, warfarin, and mixed anticoagulation regimens.

RESULTS

We identified 95,205 patients with VTE (female, 56.8%). The ASR for VTE per 100,000 person-years increased from 32.8 in 2014 to 53.7 cases in 2018 (relative risk of 1.63; 95% confidence interval, 1.6-1.67). The VTE incidence rates were 25 times higher in the ≥ 80 group than in the 30s group. VTE occurred 1.29 times more often in women than in men. The proportion of DOAC prescriptions increased from 40.5% to 72.8%, whereas warfarin prescriptions decreased from 27% to 5.6% in 2014 and 2018.

CONCLUSION

In Korea, the ASRs of VTE continued to increase since 2014, but the rate of increase slowed in 2018. The VTE occurred more often in the elderly and in women. Five years after the introduction of DOACs in 2013, they accounted for 73% of all anticoagulants used to treat VTE.

Prevention, treatment, and risk factors of deep vein thrombosis in critically ill patients in Zhejiang province, China: a multicenter, prospective, observational study

PURPOSE

The aim of this study is to investigate the prevention and treatment patterns of deep vein thrombosis (DVT) in critically ill patients and to explore the risk factors for DVT in people from Zhejiang Province, China.

MATERIALS AND METHODS

This study prospectively enrolled patients admitted in intensive care units (ICUs) of 54 hospitals from 09/16/2019 to 01/16/2020. The risk of developing DVT and subsequent prophylaxis was evaluated. The primary outcome was DVT occurrence during ICU hospitalisation. Univariate and multivariate logistic regression were performed to determine the risk factors for DVT.

RESULTS

A total of 940 patients were included in the study. Among 847 patients who received prophylaxis, 635 (75.0%) patients received physical prophylaxis and 199 (23.5%) patients received drug prophylaxis. Fifty-eight (6.2%) patients were diagnosed with DVT after admission to the ICU, and 36 patients were treated with anticoagulants (all patients received low molecular weight heparin [LMWH]). D-dimer levels (OR = 1.256, 95% CI: 1.132-1.990), basic prophylaxis (OR = 0.092, 95% CI: 0.016-0.536), and physical prophylaxis (OR = 0.159, 95% CI: 0.038-0.674) were independently associated with DVT in ICU patients. The short-term survival was similar between DVT and non-DVT patients.

CONCLUSIONS

DVT prophylaxis is widely performed in ICU patients. Prophylaxis is an independent protective factor for DVT occurrence. The most common treatment of DVT patients is LMWH, although it might increase the rate of bleeding.Key messagesThis is the only multicenter and prospective study of DVT in ICUs in China.d-dimer levels were independently associated with DVT in ICU patients.Prophylaxis was an independent protective factor for DVT occurrence in ICU.

Correlation between serum factor VIII:C levels and deep vein thrombosis following gynecological surgery

Deep vein thrombosis (DVT) is common in patients following gynecological surgery. Coagulation factor VIII (FVIII) is an important part of the human coagulation system, and FVIII:C is a component of FVIII with anticoagulant activity. 800 patients who underwent gynecological surgery were enrolled. General clinical data were harvested, and pre – and postoperative serum FVIII levels were determined. Lower-extremity ultrasound examination and/or postoperative pulmonary angiography were performed. Related data were analyzed statistically. DVT was the first manifestation of venous thromboembolism in all cases. There were a total of 46 cases, and the incidence of DVT was 5.8%. Progression to pulmonary embolism was confirmed in 16 cases, with an incidence of 2.0%. The independent risk factors for DVT after gynecological surgery were postoperative FVIII:C levels (odds ratio [OR] = 1.01), age (OR = 6.57), and operation time ≥3 hours (OR = 2.90) (P < 0.05). When the FVIII:C level was greater than the 75th centile (≥150 IU/dL), the risk of DVT was 2.99 times higher than that below the 25th centile (<100 IU/dL) (P < 0.05). When combined with the risk factor of operation time ≥3 hours, the risk increased to 3.17 times (P = 0.10). When combined with age ≥60 years, the risk was significantly increased, reaching 12.0 times (P < 0.05). Serum FVIII:C levels are an independent risk factor for DVT after gynecological surgery. Higher levels increase the risk of DVT after gynecological surgery, and they may have a dose-dependent relationship. A synergistic effect exists in combination with other risk factors, which further increases the risk.

Patients with right lower extremity deep vein thrombosis have a higher risk of symptomatic pulmonary embolism: a retrospective study of 1585 patients

OBJECTIVE

To determine the risk for pulmonary embolism (PE) and explore the relationship between the site of thrombosis and PE in patients with acute lower extremity deep vein thrombosis (DVT).

METHODS

1585 hospitalized patients first diagnosed with acute lower extremity DVT were investigated retrospectively. The patients were divided into two groups: the non-PE group (Group 1) and the PE group (Group 2). Then, Group 2 was divided into two subgroups: asymptomatic pulmonary embolism (asPE, Group 2a) and symptomatic pulmonary embolism (sPE, Group 2b). Kaplan-Meier curves and logistic regression analysis were used to explore the relevant risk factors for PE.

RESULTS

Among 1585 patients, 458 patients suffered from PE, accounting for 28.9%. 102 (22.3%) of them had the typical clinical manifestations of PE and were defined as sPE, and the remaining 356 (77.7%) patients were classified as asPE. Patients with proximal lower extremity DVT were significantly more predominant in the PE group than in the non-PE group (92.8% vs. 86.2%, p<0.001). Moreover, in Group 2, patients with typical PE manifestations showed a higher proportion of patients with right lower extremity DVT than left lower extremity DVT (26.7% vs. 17.7%, P=0.035), and bilateral lower extremity DVT than unilateral DVT (44.1% vs. 20.5%, p<0.001). By multivariate analysis, alcohol consumption (OR, 1.824; 95% CI, 1.194-2.787; p=0.005), heart failure (OR, 2.345; 95% CI, 1.560-3.526; p<0.001), proximal DVT (OR, 2.096; 95% CI,1.407-3.123; p<0.001) were independent risk factors for PE.

CONCLUSION

Patients with proximal acute lower extremity DVT were more likely to suffer from PE than those with distal DVT. Patients with right acute lower extremity DVT had a higher risk of sPE than patients with left acute lower extremity DVT. Alcohol consumption and heart failure were associated with the occurrence of PE in patients with acute lower extremity DVT.

Identification of genes, pathways and transcription factor-miRNA-target gene networks and experimental verification in venous thromboembolism

Venous thromboembolism (VTE) is a complex, multifactorial life-threatening disease that involves vascular endothelial cell (VEC) dysfunction. However, the exact pathogenesis and underlying mechanisms of VTE are not completely clear. The aim of this study was to identify the core genes and pathways in VECs that are involved in the development and progression of unprovoked VTE (uVTE). The microarray dataset GSE118259 was downloaded from the Gene Expression Omnibus database, and 341 up-regulated and 8 down-regulated genes were identified in the VTE patients relative to the healthy controls, including CREB1, HIF1α, CBL, ILK, ESM1 and the ribosomal protein family genes. The protein-protein interaction (PPI) network and the transcription factor (TF)-miRNA-target gene network were constructed with these differentially expressed genes (DEGs), and visualized using Cytoscape software 3.6.1. Eighty-nine miRNAs were predicted as the targeting miRNAs of the DEGs, and 197 TFs were predicted as regulators of these miRNAs. In addition, 237 node genes and 4 modules were identified in the PPI network. The significantly enriched pathways included metabolic, cell adhesion, cell proliferation and cellular response to growth factor stimulus pathways. CREB1 was a differentially expressed TF in the TF-miRNA-target gene network, which regulated six miRNA-target gene pairs. The up-regulation of ESM1, HIF1α and CREB1 was confirmed at the mRNA and protein level in the plasma of uVTE patients. Taken together, ESM1, HIF1α and the CREB1-miRNA-target genes axis play potential mechanistic roles in uVTE development.

Changes in Biomarkers of Coagulation, Fibrinolytic, and Endothelial Functions for Evaluating the Predisposition to Venous Thromboembolism in Patients With Hereditary Thrombophilia

The changes in the coagulation, fibrinolytic, and endothelial functions are correlated with the pathophysiology of the thromboembolic diseases during acute illness. However, these changes in patients with hereditary thrombophilia who were not in the acute stage of venous thromboembolism (VTE) are unclear. A panel of 4 biomarkers, including thrombin–antithrombin complex (TAT), plasmin-α2-plasmin inhibitor complex (PIC), tissue-type plasminogen activator/plasminogen activator inhibitor-1 complex (t-PAIC), and soluble thrombomodulin (sTM), were assayed in 100 healthy controls and 100 patients with thrombophilia. Although significantly higher concentrations of TAT, PIC, t-PAIC, and sTM were observed in patients with thrombophilia than in healthy controls, 70 patients showed absolutely normal levels of the above 4 biomarkers. Among the other 30 patients who had at least 1 biomarker out of the corresponding reference interval, 26 of them presented elevated PIC with or without increased TAT. Except for sTM, other 3 biomarkers did not show significant differences in patients with previous VTE compared to those without. Patients with single episode of VTE had obviously lower t-PAIC than those with multiple episodes of VTE, whereas the levels of TAT, PIC, and sTM were unassociated with the number of thrombosis episodes. Most thrombophilia patients who were not in the acute stage of VTE showed normal coagulation, fibrinolytic, and endothelial functions. Thus, we were unable to show that the one-time response of this panel was clinically helpful in determining thrombosis risk in thrombophilia individuals. Future studies should focus on the dynamic monitoring during the chronic phase of VTE to offer special advantages for patients with thrombophilia.

'Black Box' to 'Conversational' Machine Learning: Ondansetron Reduces Risk of Hospital-Acquired Venous Thromboembolism

Machine learning, combined with a proliferation of electronic healthcare records (EHR), has the potential to transform medicine by identifying previously unknown interventions that reduce the risk of adverse outcomes. To realize this potential, machine learning must leave the conceptual 'black box' in complex domains to overcome several pitfalls, like the presence of confounding variables. These variables predict outcomes but are not causal, often yielding uninformative models. In this work, we envision a 'conversational' approach to design machine learning models, which couple modeling decisions to domain expertise. We demonstrate this approach via a retrospective cohort study to identify factors which affect the risk of hospital-acquired venous thromboembolism (HA-VTE). Using logistic regression for modeling, we have identified drugs that reduce the risk of HA-VTE. Our analysis reveals that ondansetron, an anti-nausea and anti-emetic medication, commonly used in treating side-effects of chemotherapy and post-general anesthesia period, substantially reduces the risk of HA-VTE when compared to aspirin (11% vs. 15% relative risk reduction or RRR, respectively). The low cost and low morbidity of ondansetron may justify further inquiry into its use as a preventative agent for HA-VTE. This case study highlights the importance of engaging domain expertise while applying machine learning in complex domains.

Epidemiology of Venous Thromboembolism and Treatment Pattern of Oral Anticoagulation in Korea, 2009-2016: a Nationwide Study Based on the National Health Insurance Service Database

BACKGROUND

The annual incidence of venous thromboembolism (VTE) is increasing, and the treatment pattern of oral anticoagulants (OACs) has changed with introduction of new oral anticoagulants (NOACs). The aims of this study were to assess the annual incidence of VTE in a Korean population and the change of treatment pattern with availability of NOACs using a population-based database.

METHODS

Using the Korean National Health Insurance Services database, we identified patients diagnosed with VTE between 2009 and 2016. The annual prevalence of VTE and clinical characteristics and treatment pattern were investigated. The annual incidence of VTE was calculated using direct and indirect methods using the estimated Korean population in 2009 as the reference.

RESULTS

The annual incidence of VTE in Korean has increased yearly from 23.9 per 100,000 in 2009 to 42.2 in 2016. The overall rate of OAC prescription for VTE treatment increased from 55.9% to 68% in the same time period. The rate of initiation of NOAC treatment greatly increased, particularly from 2013 onwards, with a 20-fold increase from 2009 to 2016 (2.1% vs. 54.3%).

CONCLUSIONS

The annual incidence of VTE in Korea increased by almost two-fold from 2009 to 2016. The rate of initiation of NOAC treatment has increased substantially since 2013, and these agents have surpassed VKAs as the anticoagulant of choice for VTE. This temporal pattern of OAC prescription is consistent with the current clinical guidelines, which indicate NOACs over the warfarin in patients with VTE.

Influence of weather and air pollution on the occurrence of idiopathic pulmonary embolism in the region of Sousse (Tunisia)

Pulmonary embolism (PE) is the most serious manifestation of thromboembolic conditions. Its incidence varies considerably between countries, suggesting its interaction with the external environment. To analyze the influence of climate and air pollution on the occurrence of idiopathic PE in the region of Sousse (Tunisia). A total of 142 patients with idiopathic PE at two academic hospitals in Sousse (Tunisia) were enrolled in the study over a 7-year period. An analysis of two time series (environmental data and PE cases) was performed. Climatic data were collected from the National Institute of Meteorology. Air pollution data were obtained from the modeling platform of the National Agency for Protection of the Environment. The year 2015 was marked by the occurrence of the highest number of cases (24.6%). A statistically significant decrease in PE risk of 41.9% was observed during the summer with an OR of 0.59 (95% CI [0.36-0.94] and p = 0.026), compared with other seasons. Poisson GLM regression showed a significant increased risk of PE of 3.3% for each 1 °C temperature drop. After multiple binary logistic regression, the elevation of PM₁₀ concentration was independently associated with an increased risk of PE (p < 10^-3, OR 79.55, 95% CI [42.28-149.6]). Some environmental parameters may predispose to the onset of idiopathic PE. Understanding their accurate influence may have preventive and curative implications.

Cost-effectiveness of rivaroxaban compared with enoxaparin plus warfarin for the treatment of hospitalised acute deep vein thrombosis in China

OBJECTIVE

Limited economic evaluation data for rivaroxaban compared with standard of care (SoC) exists in China. The objective of this analysis was to evaluate the cost-effectiveness of rivaroxaban compared with current SoC (enoxaparin overlapped with warfarin) for the treatment of acute deep vein thrombosis (DVT) in China.

METHODS

A Markov model was adapted from a payer's perspective to evaluate the costs and quality-adjusted life years (QALYs) of patients with DVT treated with rivaroxaban or enoxaparin/warfarin. Clinical data from the EINSTEIN-DVT trial were obtained to estimate the transition probabilities. Data on Chinese health resource use, unit costs and utility parameters were collected from previously published literature and used to estimate the total costs and QALYs. The time horizon was set at 5 years and a 3-month cycle length was used in the model. A 5% discount rate was applied to the projected costs. One-way sensitivity analyses and probabilistic sensitivity analyses were undertaken to assess the impact of uncertainty on results.

RESULTS

Rivaroxaban therapy resulted in an increase of 0.008 QALYs and was associated with lower total costs compared with enoxaparin/warfarin (US$4744.4 vs US$5572.4, respectively), demonstrating it to be a cost-saving treatment strategy. The results were mainly sensitive to length of hospitalisation due to DVT on enoxaparin/warfarin, cost per day of hospitalisation and the difference in length of stay of rivaroxaban-treated and enoxaparin/warfarin-treated patients.

CONCLUSION

Rivaroxaban therapy resulted in a cost saving compared with enoxaparin/warfarin for the anticoagulation treatment of patients with hospitalised acute DVT in China.

TRIAL REGISTRATION NUMBER

NCT00440193; Post-results.

Efficiency and safety evaluation of prophylaxes for venous thrombosis after gynecological surgery

BACKGROUND

In this study, we investigate the incidence of venous thrombosis (VT), and evaluate the effectiveness and safety of 3 major thromboprophylaxes and the potential risk factors for VT in women undergoing surgery for a gynecological malignancy.

METHODS

We performed a randomized controlled trial of 307 patients undergoing laparoscopic surgery for gynecological malignancies at a single institution from January 2016 to October 2017. Patients were divided into 3 groups: one receiving a half dose of low-molecular-weight heparin sodium injection (FLUXUM, Alfa Wassermann, Italy) delivered by injection, one receiving a full dose of FLUXUM, and a third group receiving an Argatroban injection.

RESULTS

None of the patients in our study developed a pulmonary embolism, bleeding, or infectious complications. There were no statistical differences in the rate of deep venous thrombosis (DVT) (0%, 0%, and 2.38%) and the superficial venous thromboembolism (SVT) (15.66%, 8.97%, and 18.6%) among the 3 groups. None of the patients developed symptomatic VT. The effect of treatment on alanine aminotransferase and aspartate aminotransferase differed between the groups, with a minimal effect in the Argatroban group, and all 3 methods resulted in minimal impairment of renal function. Decreased hemoglobin, elevated levels of D-dimer, and prothrombin time were closely related to thrombogenesis.

CONCLUSION

In conclusion, the incidence of postoperative thrombosis in gynecological malignancy among these Chinese people is not as low as we had originally presumed. Argatroban is not more effective than Parnaparin as a direct thrombin inhibitor, but it has less influence on liver function, which is beneficial for patients undergoing chemotherapy. Hemoglobin, D-dimer, and prothrombin time may be used to predict or detect thrombogenesis.

A bibliometric analysis of publications on venous thromboembolism in children from 1988 to 2019

INTRODUCTION

Venous thromboembolism (VTE) in children not only imposes a heavy burden on the medical resources and economy of the society, but also seriously affects the growth and development of children, even threaten children's lives. A large number of publications have been performed in this field in recent years. In this bibliometric analysis, publications on VTE in children were examined and analyzed to explain the present research hotspots.

METHODS

Articles related to VTE in children published in the PubMed database from 1988 to June 18, 2019 were selected as the research sample. BICOMB software was used to retrieve the annual publications, journals, journal source countries and the high-frequency major medical subject headings (MeSH) terms on the articles. Then, the co-word matrix was constructed by BICOMB using the selected high-frequency MeSH terms. Next, gCLUTO software was used to analyze the matrix by double clustering and visual analysis in a strategy of hotspot identification. In addition, CiteSpace software was used to perform the knowledge map of co-authors to explore the core authors.

RESULTS

One thousand seven hundred seventy-nine articles on VTE in children were obtained. Seven hundred ninety academic journals distributed in 58 countries have published articles on VTE in children, and the developed countries and the United States were the major force in the journal source countries. Nowak-Göttl U occupied an important position in this field. We constructed a co-word matrix composing of 37 high-frequency MeSH terms, generated visual matrix and visual hill, and classified the hot-spots into 5 aspects based on 8 categories.

CONCLUSION

The results show that the research trend of children's VTE has been increasing gradually, and the sound achievement has been obtained in these hotspots in relation to the area of inherited thrombophilia, prevention and control, treatment, diagnosis, prevalence, risk factors, and complication study. However, there is a lack of communication and cooperation in this field, and the gap of national and regional research results is huge. To sum up, this study provides evidence and guidance for researchers, clinicians, and educators.

Health Economic Analysis of Rivaroxaban and Warfarin for Venous Thromboembolism Management in Chinese Patients

PURPOSE

Rivaroxaban, a direct oral anticoagulant, has demonstrated non-inferiority to warfarin for venous thromboembolism (VTE) treatment in clinical trials. This study aimed to analyze the direct medical costs for VTE management with rivaroxaban versus warfarin in Hong Kong Chinese patients.

METHODS

In this retrospective observational study, VTE patients admitted to the Princess Margaret Hospital from March 2012 to February 2017 who were initiated and discharged with either rivaroxaban or warfarin were included. Patient demographic and clinical data, and healthcare resource utilization for VTE management were collected for the VTE index admission and 1-year post-discharge period.

RESULTS

A total of 181 patients (90 in the rivaroxaban group; 91 in the warfarin group) were included. The mean (± SD) length of stay (LOS) was 4.8 ± 2.7 days and 8.0 ± 3.0 days in the rivaroxaban and warfarin groups, respectively (p > 0.001). The total cost for VTE index admission in the rivaroxaban group was significantly lower than that of the warfarin group (USD 5473 ± 1914 versus USD 3457 ± 1796; p < 0.001) (USD 1 = HKD 7.8). Recurrent VTE and bleeding rates in 1-year post-discharge period were not significantly different between the two groups. The direct total cost of the rivaroxaban group (USD 1271 ± 767) was significantly lower than that of the warfarin group (USD 1739 ± 1045) in 1-year post-discharge period (p < 0.001).

CONCLUSIONS

Total direct cost and LOS for VTE admission and total cost in 1-year post-discharge period were significantly lower in patients initiated and discharged with rivaroxaban than those of warfarin.

Relationship between the site of thrombosis and the prevalence of pulmonary embolism in acute lower extremity deep venous thrombosis

OBJECTIVE

Lower extremity deep venous thrombosis (LEDVT) is common and can lead to pulmonary embolism (PE). Currently, the mechanism of how LEDVT causes PE is unclear. The aim of this study was to explore the relationship between the thrombus sites and PE in LEDVT patients.

METHODS

A retrospective study that included the medical data of 3101 patients aged >18 years who were diagnosed with LEDVT by duplex ultrasound was performed at The First Affiliated Hospital of Wenzhou Medical University from 2008 to 2017. The clinical information of the patients was collected. According to the thrombosis sites, the patients were divided into three groups. We determined the cumulative prevalence and prevalence rate of PE between the groups and used Cox proportional hazard regression models, which were stratified on matched sets, to calculate the hazard ratios (HRs) for all of the outcomes of interest. We focused on the relationship of proximal or isolated distal LEDVT with PE and also analyzed the relationship of the left side or right side of LEDVT with PE.

RESULTS

A total of 1629 (52.5%) patients had left LEDVT (group 1), 912 (29.4%) patients had right LEDVT (group 2), and 560 (18.1%) patients had bilateral LEDVT (group 3). The rate of PE was higher in group 2 than in group 1, although there were more patients suffering from LEDVT in group 1 than in group 2 (P < .001). The patients with proximal LEDVT in group 3 exhibited a greater risk of PE compared with those with isolated distal LEDVT (adjusted HR, 2.79; 95% confidence interval, 1.42-5.49). We also observed that the proportion of patients with proximal LEDVT who were receiving treatment was much higher than that of patients with distal LEDVT (P < .05). The patients with right LEDVT had a higher risk of PE than the patients with left LEDVT (adjusted HR, 1.60; 95% confidence interval, 1.15-2.21), and the patients with right LEDVT had more comorbidities, such as malignant neoplasms, hypertension, and diabetes (P < .001).

CONCLUSIONS

Patients with proximal bilateral LEDVT had a higher likelihood for development of PE than did patients with distal LEDVT, which may be associated with inadequate therapy for proximal bilateral LEDVT. PE was more likely to develop with right-sided LEDVT because these patients had more comorbidities in our study.

Evaluation of acute pulmonary embolism and clot burden on CTPA with deep learning

OBJECTIVES

To take advantage of the deep learning algorithms to detect and calculate clot burden of acute pulmonary embolism (APE) on computed tomographic pulmonary angiography (CTPA).

MATERIALS AND METHODS

The training set in this retrospective study consisted of 590 patients (460 with APE and 130 without APE) who underwent CTPA. A fully deep learning convolutional neural network (DL-CNN), called U-Net, was trained for the segmentation of clot. Additionally, an in-house validation set consisted of 288 patients (186 with APE and 102 without APE). In this study, we set different probability thresholds to test the performance of U-Net for the clot detection and selected sensitivity, specificity, and area under the curve (AUC) as the metrics of performance evaluation. Furthermore, we investigated the relationship between the clot burden assessed by the Qanadli score, Mastora score, and other imaging parameters on CTPA and the clot burden calculated by the DL-CNN model.

RESULTS

There was no statistically significant difference in AUCs with the different probability thresholds. When the probability threshold for segmentation was 0.1, the sensitivity and specificity of U-Net in detecting clot respectively were 94.6% and 76.5% while the AUC was 0.926 (95% CI 0.884-0.968). Moreover, this study displayed that the clot burden measured with U-Net was significantly correlated with the Qanadli score (r = 0.819, p < 0.001), Mastora score (r = 0.874, p < 0.001), and right ventricular functional parameters on CTPA.

CONCLUSIONS

DL-CNN achieved a high AUC for the detection of pulmonary emboli and can be applied to quantitatively calculate the clot burden of APE patients, which may contribute to reducing the workloads of clinicians.

KEY POINTS

• Deep learning can detect APE with a good performance and efficiently calculate the clot burden to reduce the physicians' workload. • Clot burden measured with deep learning highly correlates with Qanadli and Mastora scores of CTPA. • Clot burden measured with deep learning correlates with parameters of right ventricular function on CTPA.

The Risk Factors of VTE and Survival Prognosis of Patients With Malignant Cancer: Implication for Nursing and Treatment

Venous thromboembolism (VTE) is very common in patients with malignant cancer. We aimed to conduct a retrospective analysis on the risk factors of VTE and its survival prognosis of patients with malignant cancer, to provide evidence into the management of VTE. Patients with malignant cancer treated in our hospital were selected. The characteristic of patients and related lab detection results including activated partial thromboplastin time (APTT), plasma prothrombin time (PT) and thrombin coagulation time (TT), fibrinogen (FIB), thrombin AT-Ⅲ complex (TAT) and D-dimer (D-D) were collected and analyzed. And logistic regression analyses were performed to identify the potential risk factors. And ROC curves were established to evaluate their predictive ability of VTE for patients with malignant cancers. A total of 286 patients were included, of which 63 patients had VTE, the incidence of VTE in patients with malignant cancers was 22.03%. There were significant differences on the D-D, TAT level between VTE and no VTE patients (all P < 0.05). The survival condition of VTE patients was significantly worse than that of no VTE patients(P = 0.017). D-D (RR7.895, 3.228∼19.286) and TAT (6.122, 2.244∼16.695) were risk factors of VTE for patients with cancers (all P < 0.05). The area under the curve (AUC) of D-D, TAT and combined use was 0.764, 0.698, 0.794 respectively, and the cutoff value for D-D, TAT was 1.835mg/L and 4.58μg/L respectively. For cancer patients with D-D >1.835 mg/L and TAT >4.58 μg/L, early interventions are needed for the prophylaxis of VTE.

[Perioperative Venous Thromboembolism (VTE) Prophylaxis in Thoracic Cancer Patients: Chinese Experts Consensus - Interpretation of Epidemiological Characteristics]

胸部恶性肿瘤患者围术期静脉血栓栓塞症（venous thromboembolism, VTE）是一种需要引起重视的胸外科围术期并发症，中国胸外科静脉血栓栓塞研究协作组针对胸部恶性肿瘤患者围术期VTE的预防，发布了国际首部《胸部恶性肿瘤围术期静脉血栓栓塞症预防中国专家共识》（2018版）。本文将对其中胸部恶性肿瘤围术期VTE的流行病学特征、国内外面临的挑战及预防现状进行解读，以助于更好地理解共识相关内容。

The incidence of symptomatic in-hospital VTEs in Asian patients undergoing joint arthroplasty was low: a prospective, multicenter, 17,660-patient-enrolled cohort study

PURPOSE

The aim of this study was to determine the real incidence of symptomatic in-hospital venous thromboembolism (VTE) and identify risk factors for VTEs in Asian patients undergoing total hip (THA) and total knee arthroplasty (TKA).

METHODS

A total of 17,660 patients (20,078 hips and knees) undergoing THA and TKA at 78 hospitals were enrolled. The composite incidence of symptomatic in-hospital DVT and PE was identified as the primary effectiveness outcomes. The primary safety outcomes were the incidences of postoperative complications, especially for major or minor bleeding. Secondary analyses were assessed to identify the risk factors for postoperative VTE.

RESULTS

The overall rates of symptomatic in-hospital DVT in patients undergoing THA and TKA were 0.21% (19/9022) and 0.36% (31/8638), respectively. Symptomatic PE was confirmed in one TKA patient. Safety analysis showed that the incidence of bleeding during hospital stays in patients undergoing THA and TKA was 0.10% (18/17,660). Increased VTE risks were associated with old age, high BMI index, hypertension, cerebrovascular disease, history of venous thromboembolism and no medical prophylaxis usage.

CONCLUSIONS

The incidence of symptomatic VTEs in Asian regions was low compared with that reported in studies targeting Western populations. Approximately 1 in 500 patients undergoing THA and approximately 1 in 300 patients undergoing TKA developed symptomatic VTEs prior to hospital discharge. Old age, high BMI, history of venous thromboembolism, hypertension, cerebrovascular disease, and no medication prophylaxis were risk factors identified in this study.

LEVEL OF EVIDENCE

Prospective cohort study; Level 2.

Trends in Hospitalization and In-Hospital Mortality From VTE, 2007 to 2016, in China

BACKGROUND

VTE has emerged as a major public health problem. However, data on VTE burden in China are seldom reported.

METHODS

This study collected data on patients with a principal diagnosis of VTE, pulmonary embolism (PE), or DVT by using the International Classification of Diseases, 10th Revision, from 90 hospitals across China. The trends in hospitalization rates, mortality, length of stay (LOS), and comorbidities from 2007 to 2016 were analyzed.

RESULTS

In total, 105,723 patients with VTE were identified. For patients with VTE, the age- and sex-adjusted hospitalization rate increased from 3.2 to 17.5 per 100,000 population, and in-hospital mortality decreased from 4.7% to 2.1% (P < .001). The mean LOS declined from 14 to 11 days (P < .001). In addition, the data in 2016 showed that the hospitalization rate of VTE was higher in elderly male patients (male patients vs female patients, 155.3 vs 125.4 per 100,000 population in patients aged ≥ 85 years; P < .001) and in northern China (north vs south, 18.4 vs 13.4 per 100,000 population; P < .001). Higher mortality rates were found in patients with cancer and Charlson Comorbidity Index scores > 2. Similar trends were also observed in patients with PE and those with DVT. The hospitalization rate in China was much lower than that of the United States or selected sites in Canada and Europe, the LOS was much longer, and the in-hospital mortality rates were similar.

CONCLUSIONS

The hospitalization rates of VTE increased steadily, and the mortality declined. This study provides important information on the disease burden of VTE in China.

VTE Risk Profiles and Prophylaxis in Medical and Surgical Inpatients: The Identification of Chinese Hospitalized Patients' Risk Profile for Venous Thromboembolism (DissolVE-2)-A Cross-sectional Study

BACKGROUND

Limited data exist on VTE risk and prophylaxis in Chinese inpatients. The Identification of Chinese Hospitalized Patients' Risk Profile for Venous Thromboembolism-2 (DissolVE-2), a nationwide, multicenter, cross-sectional study, was therefore designed to investigate prevalence of VTE risks and evaluate VTE prophylaxis implementation compliant with the latest prophylaxis guidelines (American College of Chest Physicians [CHEST], 9th edition).

METHODS

Adults admitted (≥ 72 h) to 60 urban, tertiary Chinese hospitals due to acute medical conditions or surgery from March to September 2016 were assessed for VTE risk. Risk assessments were made by using the Padua Prediction Scoring or Caprini Risk Assessment model, risk factors, and prophylaxis based on the CHEST guidelines, 9th edition.

RESULTS

A total of 13,609 patients (6,986 surgical and 6,623 medical) were analyzed. VTE risk in surgical inpatients was categorized as low (13.9%; 95% CI, 13.1-14.7), moderate (32.7%; 95% CI, 31.6-33.8), and high (53.4%; 95% CI, 52.2-54.6); risk in medical patients was categorized as low (63.4%; 95% CI, 62.2-64.6) and high (36.6%; 95% CI, 35.4-37.8). Major risk factors in surgical and medical patients were major open surgery (52.6%) and acute infection (42.2%), respectively. Overall rate of any prophylaxis and appropriate prophylactic method was 14.3% (19.0% vs 9.3%) and 10.3% (11.8% vs 6.0%) in surgical and medical patients.

CONCLUSIONS

A large proportion of hospitalized patients reported VTE risk and low rate of CHEST-recommended prophylaxis. The data highlight the insufficient management of VTE risk and show the great potential for improving physicians' awareness and current practices across China.

TRIAL REGISTRY

Chinese Clinical Trial Registry; No.: ChiCTR-OOC-16010187; URL: http://www.chictr.org.cn/showproj.aspx?proj=17077.

Association of the CYP4V2 polymorphism rs13146272 with venous thromboembolism in a Chinese population

Genome-wide association studies have identified the CYP4V2 polymorphism (rs13146272) as a risk factor associated with venous thromboembolism (VTE). However, due to the small sample size and variance in genetic analysis models, the relationship between VTE and rs13146272 remains unclear. Here, we performed a case-control study to analyse the associations between rs13146272 and VTE in a Chinese population and to compare the differences among various ethnicities. In this study, 226 VTE patients and 205 healthy controls were recruited, and the allele frequency of variant rs13146272 was analysed by a MassARRAY SNP genotyping assay. In addition, 9 case-control cohorts from 5 studies involving 6667 VTE-affected individuals and 8716 control subjects were included in this meta-analysis. Pooled ORs and 95% CIs were calculated to assess the association between rs13146272 and VTE by using different genetic models. Our case-control study results showed that there was no significant association between VTE and rs13146272 under the additive model (OR = 0.92, 95% CIs: 0.70-1.21, p = 0.55) in this Chinese population. However, the results of the meta-analysis performed by merging all cohorts showed that rs13146272 was significantly associated with VTE under the additive model, recessive model and dominant model. In the additive and recessive models, the association reached the threshold for genome-wide significance (p < 5.0e^-08). In conclusion, our pooled systematic study results indicated that individuals with the A allele had a higher risk of developing VTE than those with the C allele of the rs13146272 variant, but the risk was inconsistent among different ethnicities. Further validation of this association with larger sample sizes and multiple ethnicities is warranted.

Replacement of the L-iduronic acid unit of the anticoagulant pentasaccharide idraparinux by a 6-deoxy-L-talopyranose - Synthesis and conformational analysis

One critical part of the synthesis of heparinoid anticoagulants is the creation of the L-iduronic acid building block featured with unique conformational plasticity which is crucial for the anticoagulant activity. Herein, we studied whether a much more easily synthesizable sugar, the 6-deoxy-L-talose, built in a heparinoid oligosaccharide, could show a similar conformational plasticity, thereby can be a potential substituent of the L-idose. Three pentasaccharides related to the synthetic anticoagulant pentasaccharide idraparinux were prepared, in which the L-iduronate was replaced by a 6-deoxy-L-talopyranoside unit. The talo-configured building block was formed by C4 epimerisation of the commercially available L-rhamnose with high efficacy at both the monosaccharide and the disaccharide level. The detailed conformational analysis of these new derivatives, differing only in their methylation pattern, was performed and the conformationally relevant NMR parameters, such as proton-proton coupling constants and interproton distances were compared to the corresponding ones measured in idraparinux. The lack of anticoagulant activity of these novel heparin analogues could be explained by the biologically not favorable 1C4 chair conformation of their 6-deoxy-L-talopyranoside residues.

Secular trends and etiologies of venous thromboembolism in Chinese from 2004 to 2016

INTRODUCTION

Current epidemiological data for venous thromboembolism (VTE) are derived primarily from Caucasian populations from North America. Little is known for other ethnic groups. This study aimed to describe the incidence, etiologies, and the secular trends of VTE in a Chinese population.

MATERIALS AND METHODS

This was an observational study using a hospital VTE registry.

RESULTS AND CONCLUSIONS

Between 2004 and 2016, 2214 patients (mean age 66.2 ± 17.4 years, 57.2% female) were hospitalized for a novel occurrence of venous thromboembolism. Of these, 1444 patients (65.2%) had deep venous thrombosis and 770 patients (34.8%) had pulmonary embolism. Over the 13-year period, there was an increasing trend in the incidence of VTE from 28.1 per 100,000 population per year in 2004 to 48.3 per 100,000 population per year in 2016. There has been a disproportional increase in the incidence of VTE among those aged 75 years or above. Etiologically, the most common cause of VTE was active malignancy with an incidence that increased from 34.8% in 2005 to 60.9% in 2014. In conclusion, the incidence of venous thromboembolism in Hong Kong appears to be lower than that in previous Caucasian series. Nonetheless there has been an increasing incidence of VTE over the past decade, primarily related to aging and malignancy.

Bidirectional risk between venous thromboembolism and cancer in East Asian patients: synthesis of evidence from recent population-based epidemiological studies

BACKGROUND

Unprovoked (idiopathic) venous thromboembolism (VTE) with no obvious antecedent risk factors, is associated with a significant risk of subsequent occult cancer. Conversely, there is a heightened risk of VTE in cancer patients. This bidirectional risk can be estimated from population-based cohort studies conducted in East Asians.

METHODS

A literature search using medical subject heading terms and Boolean logic in PubMed and MedLine was performed in April 2017. Twenty-two papers reported from East Asia were retrieved for study and data synthesis. Proportional meta-analysis with a random-effects model was used to synthesize data with 95% confidence intervals (CIs) when appropriate.

RESULTS

Synthesis of data on VTE incidence in the East Asian population (I² = 76.2%) showed that pooled incidence was 20.3 (95% CI, 11.2-32) per 100,000 person-years. VTE incidence steadily increased with age. Unprovoked VTE accounted for 35% (95% CI, 24%-48%) of all cases of incident VTE (I² = 99.7%). The overall cancer risk was significantly higher (2.3-fold) in the VTE cohort than in comparators. Among the patients with unprovoked VTE, approximately 7% had a subsequent cancer diagnosis within 2 years of the first episode of idiopathic VTE. The risk of VTE recurrence was increased in cancer patients (adjusted odds ratio, 1.64; 95% CI, 1.26-1.99). VTE incidence was 9.9 per 1,000 person-years in cancer patients, particularly in liver, pancreas, and lung cancer patients.

CONCLUSION

Newly diagnosed VTE incidence is estimated at approximately 4,400 new cases annually in Taiwan and 7,100 in South Korea. Similar to the trend in VTE incidence among the general population, VTE risk in East Asian cancer patients is markedly lessened.