Incidence of venous thromboembolism in Korea from 2009 to 2013

Emergency medicine residents' learning curve in diagnosing deep vein thrombosis with 3-point venous point-of-care ultrasound

BACKGROUND

Many cases of deep vein thrombosis (DVT) are diagnosed in the emergency department, and abbreviated lower extremity venous point-of-care ultrasound (POCUS) has already shown an accuracy comparable to that of specialists. This study aimed to identify the learning curve necessary for emergency medicine (EM) residents to achieve expertise-level accuracy in diagnosing DVT through a 3-point lower extremity venous POCUS.

METHODS

This prospective study was conducted at an emergency department between May 2021 and October 2022. Four EM residents underwent a one-hour POCUS training session and performed DVT assessments in participants with DVT symptoms or confirmed pulmonary embolism. POCUS was performed at three proximal lower extremity sites to evaluate the thrombi presence and vein compressibility, with results validated by specialized radiology ultrasound. Cumulative sum (CUSUM) and the Bush and Mosteller models were used to analyze the learning curve, while generalized estimating equations were used to identify factors affecting diagnostic accuracy.

RESULTS

91 POCUS scans were conducted in 49 patients, resulting in 22% DVT confirmed by specialized venous ultrasound. In the CUSUM analysis, all four EM residents attained a 90% success rate at the common femoral vein, whereas only half achieved this rate when all three sites were considered. According to Bush and Mosteller models, 13-18 cases are required to attain 90-95% diagnostic accuracy. After 10-16 cases, the examination time for each resident decreased, and a 20% increase in examiner confidence was linked to a 2.506-fold increase in the DVT diagnosis accuracy.

CONCLUSION

EM residents generally required 13-18 cases for 90-95% DVT diagnostic accuracy, but proficiency varied among individuals, particularly requiring more cases for regions outside the common femoral vein.

Characteristics of factor V and protein C based on results from Korean testing centers

OBJECTIVE

The global incidence of thrombosis is increasing. However, research on thrombosis in the context of Korea is scarce. We aimed to analyze the relationship between factor V and protein C test results and thrombosis in Koreans through a domestic commissioned testing institution conducting mass examinations.

METHODS

Results of factor V and protein C tests of 1386 individuals referred simultaneously to EONE Laboratories (Incheon, Republic of Korea) from January 2017 to July 2023 were analyzed retrospectively to identify the association with thrombotic disease. The tests were performed using a STAR MAX (Diagnostica Stago, Asnieres, France) automatic blood coagulation analyzer. The results were analyzed by age and sex.

RESULTS

The inspection rate increased gradually from 2017 to 2022. Women (70.0%) demonstrated a higher test rate than did men (30.0%). Young women reported high test rates; the test rate and age distribution differed by sex. Women aged between 20 and 49 years reported lower factor V and higher protein C concentrations than did men between 20 and 49 years of age.

CONCLUSIONS

The tests were more commonly performed in women than in men. Women aged between 20 and 49 years reported lower factor V concentrations and higher protein C concentrations than men between 20 and 49 years of age. This study will facilitate recognizing and preventing thrombotic diseases in women.

Is early bilateral compression ultrasonography and D-dimer monitoring appropriately for prophylaxis and diagnosis of deep venous thrombosis after cesarean section women: a single-center observation study of Chinese Han population

BACKGROUND

Venous thromboembolism (VTE) is most prevalent among parturients following a cesarean section (CS). The objective of this study was to assess the practical utility of bilateral compression ultrasonography (CUS) of the lower limbs, coupled with D-dimer monitoring, in the early diagnosis of VTE within the Han Chinese population.

METHODS

Our prospective observational study included 742 women who underwent CUS and D-dimer testing on the first day post-CS. Subsequently, telephone or outpatient follow-ups were conducted until 42 days postpartum. States of hypercoagulation and thrombosis, as indicated by CUS, were classified as CUS abnormal. A D-dimer level ≥ 3 mg/l was considered the D-dimer warning value. Early ambulation and mechanical prophylaxis were universally recommended for all parturients post-CS. A sequential diagnostic strategy, based on the 2015 RCOG VTE risk-assessment tool, was employed. Therapeutic doses of low-molecular-weight heparin (LMWH) were administered for the treatment of thromboembolic disease. Prophylactic doses of LMWH were given for VTE prophylaxis in parturients with hypercoagulative status accompanied by D-dimer levels ≥ 3 mg/l. All high-risk women (RCOG score ≥ 4 points) were additionally treated with preventive LMWH. Statistical analyses were conducted using the R statistical software, with a two-sided P value < 0.05 considered statistically significant.

RESULTS

Fifteen cases of VTE and 727 instances without VTE were observed. The overall VTE rate post-CS was 2.02% (15/742), with 66.7% (10/15) being asymptomatic. Eleven patients received a VTE diagnosis on the first postpartum day. Among the 41 parturients exhibiting hypercoagulation ultrasound findings and D-dimer levels ≥ 3 mg/l, despite receiving pharmacological VTE prophylaxis with LMWH, 4.88% (2/41) in the high-risk group were eventually diagnosed with VTE. A total of 30.86% (229/742) exhibited normal ultrasound findings and D-dimer levels < 3 mg/l on the first day post-CS, with no VTE occurrences in the postpartum follow-up. According to RCOG's recommendation, 78.03% (579/742) of cesarean delivery women should receive prophylactic anticoagulation, while only 20.62% (153/742) met our criterion for prophylactic anticoagulation.

CONCLUSION

The strategy of timely routine bilateral CUS and D-dimer monitoring is conducive to the early diagnosis and treatment of VTE, significantly reducing the use of LMWH in the Chinese Han population.

Risk of thromboembolism according to statin treatment in patients with cancer: A nationwide nested case-control study

BACKGROUND

Thromboembolic events exhibit increased prevalence in patients with cancer and can negatively affect prognoses. We investigated whether statin treatment would reduce thromboembolic risk in patients with cancer.

METHODS

We conducted a nested case-control study using a Korean nationwide health claims database. The study included patients newly diagnosed with cancer without a prior history of cardiovascular disease between 2014 and 2016. Cases who developed arterial thromboembolism (ATE) or venous thromboembolism (VTE) after cancer diagnosis and three individually matched controls were selected. Conditional logistic regression was used to assess the association between thromboembolic risk and statin therapy after cancer diagnosis.

RESULTS

Among 455,805 newly diagnosed patients with cancer followed for a mean of 4.3 ± 2.0 years, 22,249 patients developed thromboembolic events (ATE: 6341, VTE: 15,908), resulting in an incidence rate of 1133 per 100,000 person-years. The nested case-control study included 21,289 cases with thromboembolic events and 63,867 controls. Statin use was less frequent in the case group (18.0 % vs. 23.7 %). Statin treatment was associated with a lower risk of thromboembolic events (adjusted odds ratio [OR] 0.70; 95 % confidence interval [CI] 0.67-0.73). This association was observed for both ATE (adjusted OR 0.68; 95 % CI 0.63-0.74) and VTE (adjusted OR 0.71; 95 % CI 0.67-0.75). Longer statin use and better adherence were also associated with lower risk for thromboembolic events. Statin treatment was significantly associated with fewer thromboembolic events in most cancer types.

CONCLUSIONS

Statin use was associated with lower risk for thromboembolic events in patients newly diagnosed with cancer.

Increased risk of venous and arterial thromboembolism in patients with colorectal cancer receiving cetuximab-based combination chemotherapy: A population-based study in Korea

INTRODUCTION

Limited data exist on the risk of venous and arterial thromboembolisms (VTE and ATE) in patients receiving cetuximab plus chemotherapy. We aimed to determine the thromboembolic risk of patients with recurrent/metastatic colorectal cancer (CRC) treated with cetuximab plus chemotherapy compared to chemotherapy alone.

METHODS

This population-based study used nationwide claims data from the Health Insurance Review and Assessment Service of South Korea from 2013 to 2020. Patients with recurrent/metastatic CRC treated with first-line oxaliplatin- or irinotecan-based doublets with or without cetuximab and no secondary prevention for VTE and ATE were included. Primary outcomes were the occurrence of any thromboembolic events, VTE, and ATE, which were determined using the cumulative incidence method incorporating death as a competing event.

RESULTS

We identified 19,723 patients (cetuximab plus chemotherapy, N = 7630; chemotherapy alone, N = 12,093). The cumulative incidence of any thromboembolic events in patients with cetuximab plus chemotherapy was significantly higher than in those receiving chemotherapy alone (6-month, 5.62 % vs. 3.58 %, P < 0.0001). The rates of VTE (6-month, 5.11 % vs. 3.28 %, P < 0.0001) and ATE (6-month, 0.53 % vs. 0.32 %, P = 0.0218) were also higher in patients receiving cetuximab plus chemotherapy. In multivariable analysis, cetuximab plus chemotherapy was independently associated with developing any thromboembolic events (hazard ratio [HR], 1.63; 95 % confidence interval [CI], 1.42-1.87), VTE (HR, 1.62; 95 % CI, 1.40-1.87), and ATE (HR, 1.77; 95 % CI, 1.16-2.71).

CONCLUSIONS

Cetuximab with irinotecan- or oxaliplatin-based doublet chemotherapy was associated with an increased risk of any thromboembolic events, VTE, and ATE; further studies are warranted to examine the underlying mechanisms.

Incidence of Pregnancy-Associated Venous Thromboembolism: Second Nationwide Study

BACKGROUND

 Pregnancy is a transient risk factor for venous thromboembolism (VTE). This second nationwide study aimed to inspect trend changes in the incidence rate of pregnancy-associated VTE (PA-VTE) during the study period (2014-2018) compared with that reported in a previous study (2006-2010).

METHODS

 Using the Korean Health Insurance Review and Assessment Service database, we retrospectively identified all PA-VTE events using both diagnostic and medication codes.

RESULTS

 Of the 124,228 VTE events, 510 (0.4%) cases of PA-VTE were identified in 499 women (median age: 34 years; range: 20-49 years). The incidence rate of PA-VTE/10,000 deliveries (PA-VTE/104D) in this second study (2.62) was 3.2 times higher than that in the first study (0.82). In the second study, the PA-VTE/104D ratio of women in their 40s (5.46) was three times higher than that of women in their 20s (1.80) (relative risk: 3.03; 95% confidence interval: 2.04-4.51; p < 0.01). The incidence rate for women in their 40s in the second study was 2.3 times higher than that in the first study. PA-VTE/104D cases occurred more frequently in multiparous than in primiparous women, in cesarean section cases compared with vaginal delivery, and in multiple rather than single pregnancies. Most PA-VTE cases occurred during the postpartum period (321/510, 62.9%), of which pulmonary embolism was the most frequently occurring type (231/321, 72%).

CONCLUSION

 Advanced maternal age, cesarean section, multiparity, and multifetal pregnancies increased the risk of PA-VTE. Obstetricians need to be cautious of VTE, particularly during the postpartum period, in high-risk pregnant patients.

Application of the Khorana score for cancer-associated thrombosis prediction in patients of East Asian ethnicity undergoing ambulatory chemotherapy

BACKGROUND

The Khorana score (KS) has not been well studied in East Asian cancer patients, who have different genetic backgrounds for inherited thrombophilia, body metabolism, and cancer epidemiology.

METHODS

By using the Common Data Model, we retrospectively collected deidentified data from 11,714 consecutive newly diagnosed cancer patients who underwent first-line chemotherapy from December 2015 to December 2021 at a single institution in Korea, and we applied the KS for cancer-associated thrombosis (CAT) prediction. Age at diagnosis, sex, and use of highly thrombogenic chemotherapeutics were additionally investigated as potential risk factors for CAT development.

RESULTS

By 6 months after chemotherapy initiation, 207 patients (1.77%) experienced CAT. Only 0.4% had a body mass index (BMI) ≥ 35 kg/m² and changing the cutoff to 25 kg/m² improved the prediction of CAT. Age ≥ 65 years and the use of highly thrombogenic chemotherapeutics were independently associated with CAT development. KS values of 1 ~ 2 and ≥ 3 accounted for 52.3% and 7.6% of all patients, respectively, and the incidence of CAT in these groups was 2.16% and 4.16%, respectively, suggesting a lower incidence of CAT in the study population than in Westerners. The KS component regarding the site of cancer showed a good association with CAT development but needed some improvement.

CONCLUSION

The KS was partially validated to predict CAT in Korean cancer patients undergoing modern chemotherapy. Modifying the BMI cutoff, adding other risk variables, and refining the use of cancer-site data for CAT risk prediction may improve the performance of the KS for CAT prediction in East Asian patients.

Epidemiology and prevention of venous thromboembolism

Venous thromboembolism, that consists of the interrelated conditions deep-vein thrombosis and pulmonary embolism, is an under-appreciated vascular disease. In Western regions, approximately 1 in 12 individuals will be diagnosed with venous thromboembolism in their lifetime. Rates of venous thromboembolism are lower in Asia, but data from other regions are sparse. Numerous risk factors for venous thromboembolism have been identified, which can be classified as acute or subacute triggers (provoking factors that increase the risk of venous thromboembolism) and basal or acquired risk factors (which can be modifiable or static). Approximately 20% of individuals who have a venous thromboembolism event die within 1 year (although often from the provoking condition), and complications are common among survivors. Fortunately, opportunities exist for primordial prevention (prevention of the development of underlying risk factors), primary prevention (management of risk factors among individuals at high risk of the condition) and secondary prevention (prevention of recurrent events) of venous thromboembolism. In this Review, we describe the epidemiology of venous thromboembolism, including the incidence, risk factors, outcomes and opportunities for prevention. Meaningful health disparities exist in both the incidence and outcomes of venous thromboembolism. We also discuss these disparities as well as opportunities to reduce them.

Applicability of the Padua scale for Chinese rheumatic in-patients with venous thromboembolism

OBJECTIVE

To investigate the risk factors for venous thromboembolism (VTE) in hospitalized patients with rheumatic diseases in China. The efficacy of the Padua scale was evaluated and an improved model for predicting VTE in hospitalized patients with rheumatic diseases was developed.

METHODS

Records of 2282 patients hospitalized in the department of rheumatology of the Sichuan Provincial People's Hospital were retrospectively reviewed. The risk factors for VTE were analyzed. The efficacy of the Padua scale was evaluated, Padua-combined prediction model and the independent risk factor-combined prediction model for predicting VTE were assessed using the receiver operating curve (ROC).

RESULTS

A total of 50 patients in the VTE group and 2232 in the non-VTE group were included. Antiphospholipid syndrome (APS), VTE history, a hospital stay of over 3 days, high D-dimer (D-D), and decreased serum albumin were independent risk factors for VTE. APS was very closely associated with VTE (OR = 19.446). Padua scores in the VTE group and the non-VTE group were 3 (2, 6) and 2 (1, 2) points, respectively (p < 0.05), and the proportion of high-risk patients were 48.0% and 7.4%, respectively (p < 0.05). The incidence of VTE in the high-risk (Padua score ≥4) and low-risk (Padua score <4) groups was 12.7% and 1.2%, respectively (p < 0.05). The area under curve (AUC) of the Padua scale, Padua combined prediction model (Padua scale along with D-D and serum albumin), and the independent risk factor-combined prediction model was 0.771, 0.836, and 0.873, respectively.

CONCLUSION

The Padua scale has limited predictive efficacy of VTE in hospitalized rheumatic patients. The independent risk factor-combination prediction model was superior in predicting VTE compared to Padua scale and Padua-combined prediction model.

A multicenter, open-label study for efficacy and safety evaluation of anagrelide in patients with treatment-naïve, high-risk essential thrombocythemia as a primary treatment

As the discussion of first-line anagrelide treatment is ongoing, we aimed to prospectively examine the efficacy and safety of anagrelide in cytoreduction therapy-naïve high risk essential thrombocythemia (ET) patients in Korea. Seventy patients from 12 centers were treated with anagrelide monotherapy for up to 8 weeks, followed up until 24 months. At week 8, 50.0% of the patients were able to achieve platelet < 600 x 109/L, and by 12 months, 55/70 (78.6%) patients stayed on anagrelide, and 40.0% patients showed platelet normalization. 14 patients required additional hydroxyurea (HU) for cytoreduction. The median daily dose of needed HU was 500mg (range 250mg - 1500mg). The efficacy was independent of the somatic mutation status. There were 4 thromboembolic events and 7 bleeding events during the follow-up period. The most common adverse events associated with anagrelide use were headache, followed by palpitation/chest discomfort, edema and generalized weakness/fatigue. 7 patients wished to discontinue anagrelide treatment due to adverse events (3 due to headache; 2 due to edema; 1 due to palpitation and 1 due to skin eruption). All in all, first-line anagrelide treatment showed a favorable response with tolerable safety profiles regardless of somatic mutation status.

Pharmacotherapy for pulmonary embolism: new anticoagulants

Background: Pulmonary embolism is associated with reduced survival and considerable economic burden worldwide. In Korea, the incidence of pulmonary embolism has been gradually increasing. Older individuals are at an increased risk for pulmonary embolism and anticoagulation-related bleeding events. Typically, heparin and vitamin K antagonists are employed to treat pulmonary embolism; however, these agents present numerous limitations. Hence, novel anticoagulants with improved safety and efficacy profiles are urgently needed.Current Concepts: Direct oral anticoagulants (DOACs), including direct thrombin (coagulation factor II) inhibitors and selective inhibitors of coagulation factor Xa, have emerged as alternative agents. Phase III, large-scale clinical trials have revealed that DOACs are non-inferior to standard therapy during initial and long-term treatment of pulmonary embolism, considering the safety profile. Evidence-based clinical guidelines recommend that primary care clinicians employ DOACs over warfarin to achieve anticoagulation.Discussion and Conclusion: For over 70 years, the standard therapy for most patients with pulmonary embolism has involved heparin administration, overlapped and followed by a vitamin K antagonist. Recently developed DOACs against coagulation factor Xa or thrombin might overcome limitations of standard therapy, including the need for injection and regular dose adjustment with laboratory monitoring. These limitations hinder the management of patients with pulmonary embolism and negatively impact the patient’s quality of life. Four DOACs, including apixaban, dabigatran, edoxaban, and rivaroxaban, are currently available for treating pulmonary embolism in Korea, which could simplify the therapeutic strategy.

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.

Clinical outcomes of patients who received a lower dose of non-vitamin K antagonist oral anticoagulants for the medical management of acute pulmonary embolism

BACKGROUND

Non-vitamin K antagonist oral anticoagulants (NOACs) are used to treat acute pulmonary embolism (PE). However, lower NOAC doses are often prescribed because of increased risk of NOAC complications.

OBJECTIVE

We sought to determine the incidence and clinical outcomes of patients with acute provoked PE receiving lower NOAC doses.

METHOD

140 patients with acute PE with only NOACs used for medical management was enrolled and were followed up for 6 months. The composite primary endpoint was all-cause death, venous thromboembolism recurrence, and residual thrombus on follow-up computed tomography.

RESULTS

Of the 140 patients, 99 (70.7%) received the standard NOAC dose and 41 (29.3%) received the lower dose. The crude incidences of the primary endpoint were 19 (19.2%) in patients who received the standard NOAC dose and 13 (31.7%) in those who received the lower dose. Compared with patients who received the standard dose, those who received the lower dose had no differences in the rate of primary endpoints (hazard ratio 1.140, 95% confidence interval 0.536-2.423, p = 0.733) during a median of 185 days.

CONCLUSION

We found that up to 30% of patients received the lower dose of NOACs for acute PE in clinical practice. Clinical outcomes with appropriate underdoing of NOAC treated in acute PE might not increase compared to the standard NOAC doses.

Internal Validation of a Risk Scoring System for Venous Thromboembolism After Total hip or Knee Arthroplasty

We developed a computerized clinical decision support system (CCDSS) for venous thromboembolism (VTE) risk assessment. We aimed to demonstrate its relevance and evaluate associations between risk level and VTE incidence in patients undergoing total hip/knee arthroplasty. In this case-control study, VTE was confirmed using ultrasonography/computed tomography angiography in 1098 adults at a tertiary care hospital over five years (2013-2018). Postoperative VTE incidence was classified into three risk levels (moderate, high, and highest). The overall VTE incidence was 11.7%, which increased with a risk level of 0%, 5.8%, and 12.8% in moderate-risk, high-risk, and highest-risk patients, respectively. Highest-risk patients were significantly more likely to develop VTE than high-risk patients (odds ratio [OR] 2.4; 95% confidence interval [CI] 1.2-5.5; p = 0.01). VTE development was more likely in patients with risk scores ≥4 relative to those with risk scores of 2-3 (OR 1.8; 95% CI 1.2-2.7; p = 0.003) and -1 to 1 (OR 3.3; 95% CI 1.6-7.7; p < 0.001). This study indicates that risk level and VTE incidence are associated; our scoring system appears useful for patients undergoing total hip/knee arthroplasty.

Effects of menopausal hormone therapy on cardiovascular diseases and type 2 diabetes in middle-aged postmenopausal women: analysis of the Korea National Health Insurance Service Database

OBJECTIVE

Although menopausal hormone therapy (MHT) is the most effective treatment for menopausal symptoms, menopausal women hesitate to start MHT due to concerns about adverse events. Recently, however, it has been recommended to use it for appropriate patients who have been evaluated for baseline diseases, age, and timing of initiation. We aimed to investigate the association of MHT with cardiovascular diseases (CVDs) and type 2 diabetes among middle-aged postmenopausal women in Korea.

METHODS

Data were collected from the National Health Insurance Service database in Korea from 2002 to 2016. A total of 58,060 postmenopausal women (including 8,013 [13.8%] MHT users and 50,047 [86.2%] nonusers) were included. The time-dependent Cox regression model with a 1-year latency period was used to evaluate the hazard ratio (HR) and 95% confidence interval (CI) of the associations of MHT with CVDs and type 2 diabetes outcomes. Subgroup analyses by regimen type and cumulative duration were conducted.

RESULTS

In the multivariate-adjusted model, MHT was not significantly associated with CVDs (HR = 1.085, 95% CI: 0.899-1.310) or type 2 diabetes (HR = 1.104, 95% CI: 0.998-1.221). Differential effects were not observed by regimen type, cumulative duration, and years since menopause subgroups. Sensitivity analyses also did not show adverse events by MHT on CVDs and type 2 diabetes.

CONCLUSIONS

Although protective effects of MHT against CVDs or type 2 diabetes were not observed among postmenopausal women who had screened underlying diseases, our results may contribute to reducing the current concerns about the use of MHT for middle-aged postmenopausal women in Korea.

Incidence, characteristics and risk factors of thromboembolic events in East Asian patients with BCR-ABL1 negative myeloproliferative neoplasms

The vascular complications have been a major cause of morbidity and mortality among all subtypes of BCR-ABL1 negative myeloproliferative neoplasms (MPN), but the ethnicity-specific data was limited. We therefore conducted a multi-center retrospective, longitudinal cohort study to evaluate the incidence, characteristics and risk factors of thromboembolic events of MPN patients. Of 256 patients, 27.3% experienced thromboembolic events, majority of which occurred before or within 12 months of MPN diagnosis. The multivariable Cox proportional analyses identified leukocytosis (HR 2.67, 95% CI 1.36-5.24, q = 0.004) and history of thrombosis (HR 9.68, 95% CI 2.00-46.88, q = 0.005) as the risk factors for thromboembolism. In subgroup analysis of polycythemia vera and hemoglobin concentration (HR 1.97, 95% CI 1.28-3.04, q = 0.002) appeared to be a significant risk factor of thrombosis, along with age and thrombosis history. In essential thrombocythemia, severity of the established IPSET score was closely correlated with the frequency of thromboembolic events. In primary myelofibrosis, history of thrombosis was associated with thrombosis events (HR 13.85, 95% CI 1.2-159.5, q = 0.035). Overall survival was worse in patients who experienced thromboembolic events. Our study highlighted the importance of recognizing high risk patients and implementing personalized intervention.

Application of the RCOG Risk Assessment Model for Evaluating Postpartum Venous Thromboembolism in Chinese Women: A Case-Control Study

BACKGROUND Since China has not yet constructed its own risk assessment model (RAM) for pregnancy-related venous thromboembolism (VTE), more and more hospitals use the RCOG RAM for VTE risk prediction. However, the RCOG RAM was established based on Western populations, and its applicability in China is still uncertain. Thus, we aimed to evaluate the validity of the RCOG RAM in predicting postpartum VTE in Chinese maternity. MATERIAL AND METHODS This retrospective case-control study was conducted at the International Peace Maternity and Child Health Hospital (IPMCHH) from June 2016 to June 2020. The VTE group consisted of 38 women with postpartum VTE. For each VTE patient, 4 women without VTE who gave birth on the same day were randomly selected as the control group (n=152). The receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis (DCA) were used to evaluate the discrimination, accuracy, and validity of the RCOG RAM. Univariable analysis and multivariable logistic regression analysis were used to identify other related factors for postpartum VTE. RESULTS Compared with the low-risk group, the risk of VTE was 9.75-fold greater in the intermediate-risk group, and 90.00-fold greater in the high-risk group. The area under curve (AUC) of the model was 0.828 (95% CI: 0.762-0.894), with a score of 2 as its best cut-off value, which exactly matched the criterion recommended by the RCOG guidelines for pharmacological thromboprophylaxis. The calibration curves and DCA of the model also showed good accuracy. In addition to the factors included in the RCOG RAM, glucocorticoid therapy during pregnancy (adjusted OR=6.72, 95% CI: 1.56-28.91) and previous use of IUD (adjusted OR=7.11, 95% CI: 1.45-34.93) were associated with increased risk of postpartum VTE. CONCLUSIONS The RCOG RAM was found to be effective in predicting postpartum VTE, and has certain guiding significance for postpartum thromboprophylaxis in China.

Lenalidomide for anemia correction in lower-risk del(5q) myelodysplastic syndrome patients of Asian ethnicity

Background

To estimate real-world outcomes in East Asian populations, we conducted a nationwide retrospective analysis of the efficacy and safety of lenalidomide for del(5q) myelodysplastic syndrome (MDS) patients with transfusion-dependent anemia in Korea.

Methods

Patients aged ≥19 years who had received lenalidomide for the treatment of lower-risk, red blood cell (RBC) transfusion-dependent del(5q) MDS were selected. A filled case report form (CRF) with information from electronic medical records was requested from members of the acute myeloid leukemia (AML)/MDS Working Party of the Korean Society of Hematology. All the CRFs were gathered and analyzed.

Results

A total of 31 patients were included in this study. Of 28 evaluable patients, 19 (67.9%) achieved RBC transfusion independence (RBC-TI). Female sex and the development of thrombocytopenia during treatment were associated with achieving RBC-TI. The most common non-hematologic toxicities were pruritus, fatigue, and rashes. All non-hematologic toxicities of grades ≥3 were limited to rash (12.9%) and pruritus (6.5%). Dose reduction was required in 15 of the 19 responders (78.9%). The most common final stable dosing schedule for the responders was 5 mg once every other day (31.6%).

Conclusion

Lenalidomide efficacy and tolerability were similar in the Asian del(5q) MDS patients and western patients. Dose reduction during treatment was common, but it was not associated with inferior outcomes.

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.

Updated recommendations for the treatment of venous thromboembolism

Venous thromboembolism (VTE), which includes pulmonary embolism and deep vein thrombosis, is a condition characterized by abnormal blood clot formation in the pulmonary arteries and the deep venous vasculature. It is often serious and sometimes even fatal if not promptly and appropriately treated. Moreover, the later consequences of VTE may result in reduced quality of life. The treatment of VTE depends on various factors, including the type, cause, and patient comorbidities. Furthermore, bleeding may occur as a side effect of VTE treatment. Thus, it is necessary to carefully weigh the benefits versus the risks of VTE treatment and to actively monitor patients undergoing treatment. Asian populations are known to have lower VTE incidences than Western populations, but recent studies have shown an increase in the incidence of VTE in Asia. A variety of treatment options are currently available owing to the introduction of direct oral anticoagulants. The current VTE treatment recommendation is based on evidence from previous studies, but it should be applied with careful consideration of the racial, genetic, and social characteristics in the Korean population.

Radiomics study on pulmonary infarction mimicking community-acquired pneumonia

INTRODUCTION AND OBJECTIVES

Pulmonary infarction (PI) shares similar symptoms and imaging presentations with community-acquired pneumonia (CAP), which might delay diagnosis and lead to devastating consequences. Noncontrast computed tomography (CT) is the first-line examination for the patients with the respiratory symptoms. This study aimed to investigate a radiomics method to differentiate PI from CAP using noncontrast-enhanced CT.

METHODS

Noncontrast-enhanced CT images of 54 patients with PI and 64 patients with CAP were retrospectively selected. All patients were confirmed using computed tomography pulmonary angiography (CTPA). A radiomics model was built with 18 texture features that showed significant differences between PI and CAP patients. For comparison, a clinical model using clinical biomarkers and an integrated model combining the radiomics and clinical biomarkers were also generated. An experienced radiologist performed diagnoses using the noncontrast-enhanced CT images. The parameters of the models were generated using a training dataset of 61 patients, whereas the performance of the models was evaluated using receiver operating characteristic (ROC) analysis and Harrell's concordance index (C-index) applied to a separate validation dataset of 57 patients.

RESULTS

The integrated model achieved the best performance (C-index 0.760, sensitivity 0.703, specificity 0.867, positive predictive value [PPV] 0.826, and negative predictive value [NPV] 0.765). The radiomics model was better than both the clinical model and the radiologist's interpretations (C-index 0.721, 0.707, 0.665, respectively; sensitivity 0.667, 0.630, 0.593; specificity 0.800, 0.785, 0.733; PPV 0.750, 0.739, 0.667; and NPV 0.727, 0.706, 0.667).

CONCLUSIONS

Radiomics features generated from noncontrast-enhanced CT images allow PI to be differentiated from CAP with considerable accuracy. The radiomics-based method could provide useful information in clinical practice.

Incidence of venous thromboembolism after standard treatment in patients with epithelial ovarian cancer in Korea

Background

Venous thromboembolism (VTE) is a hospital‐associated severe complication that may adversely affect patient prognosis. In this study, we evaluated the incidence of VTE and its risk factors in patients with epithelial ovarian cancer (EOC).

Methods

We retrospectively analyzed the electronic health record data of 1268 patients with EOC who received primary treatment at the National Cancer Center, Korea between January 2007 and December 2017 to identify patients who developed VTE. Demographic, clinical, and surgical characteristics of these patients were ascertained. Competing risks analyses were performed to estimate the cumulative incidence of VTE according to the treatment type. The associations between putative risk factors and the incidence of VTE were evaluated using the Fine–Gray regression models accounting for competing risks of death.

Results

VTE was the most prevalent cardiovascular event, found in 9.6% (n = 122) of all patients. Of these VTE events, 115 (94.3%) occurred within 2 years of EOC diagnosis. Advanced cancer stage at diagnosis (distant vs. localized, hazards ratio [HR])= 14.49, p = 0.015) and extended hospital stay (≥15 days, HR =3.87, p = 0.004) were associated with the incidence of VTE. There was no significant difference in the cumulative incidence of VTE between primary cytoreductive surgery followed by adjuvant chemotherapy and neoadjuvant chemotherapy followed by interval cytoreductive surgery (HR =0.81, p = 0.390).

Conclusions

Approximately 10% of patients with EOC were diagnosed with VTE, which was the most common cardiovascular disease found in this study. The assessment of VTE risks in patients with advanced‐stage EOC with an extended hospital stay is needed to facilitate adequate prophylactic treatment.

Incidence of Major Bleeding in Patients with Pulmonary Thromboembolism Treated with Fixed Dose Alteplase 100 mg

BACKGROUND

Acute pulmonary thromboembolism (PTE) is a critical cardiopulmonary condition associated with high mortality and morbidity. In massive PTE, recently referred to as high risk PTE, the routine protocol for thrombolysis with recombinant tissue plasminogen activator (alteplase) is 100 mg over 2 hours. However, there are concerns about bleeding in patients with low body weight (< 50 kg), elderly patients, and Asians.

METHOD

We performed a retrospective study in patients who were diagnosed with intermediate or high risk PTE, and who were treated with a fixed dose of alteplase (100 mg) in a single center at Chungbuk National University Hospital between July 2008 and April 2018.

RESULTS

A total of 42 patients were reviewed, 4 patients dropped out, and 38 patients were included in the analysis. There were 18 males (47.4%), and the average age of the patients was 70.68 years (± standard deviation 13.15). Major bleeding was seen in 10/38 patients (26.3%), and 30/38 patients (78.9%) were successfully discharged.

CONCLUSION

The major bleeding risk was higher in our study (26.3%) than in a previously published meta-analysis (9.24%). Therefore, we suggest reducing the dose of alteplase in patients who are elderly, Asian, or have cardiovascular disease. Further prospective studies of efficacy and bleeding rate after low dose alteplase should be considered.

Prediction of deep vein thrombosis by ultrasonography and D-dimer in Asian patients with ischemic stroke

Background

Deep vein thrombosis (DVT) is an important complication of ischemic stroke, although the incidence of DVT is regarded as being lower in Asian than in non-Asian patients. Here, we investigated the incidence and factors associated with DVT in Asian patients with ischemic stroke.

Methods

Acute ischemic stroke patients received lower extremity ultrasonography (LEUS) to diagnose the presence of DVT. Clinical characteristics and laboratory results, including D-dimer level, were compared between patients with and without DVT. Independent risk factors for DVT were investigated using multivariable analysis. Similar analysis was performed to identify factors associated with elevated D-dimer level (> 0.5 mg/dl) in acute ischemic stroke patients.

Results

During the study period, 289 patients were enrolled, and 38 (13.1%) showed DVT. Female sex (OR = 2.579, 95% CI = 1.224–5.432; p = 0.013) and a high National Institutes of Health Stroke Scale (NIHSS) score (OR = 1.191 95% CI = 1.095–1.294; p = 0.005) were independently associated with the presence of DVT, although D-dimer level was not. Stroke mechanism, especially cardioembolic stroke (OR = 3.777, 95% CI = 1.532–9.313; p = 0.004; reference: large artery atherosclerosis), NIHSS score (OR = 1.087, 95% CI = 1.002–1.179; p = 0.001) and thrombolysis (OR = 12.360, 95% CI 2.456–62.213; p = 0.002) were independently associated with elevated abnormal D-dimer levels.

Conclusion

The severity of ischemic stroke, but not the D-dimer level, was associated with the presence of DVT in Asian ischemic stroke patients. D-dimer level was influenced by the stroke mechanism. LEUS in patients with severe neurological deficit, rather than screening with D-dimer, may be more beneficial for diagnosing DVT in Asian patients with acute ischemic stroke.

Prominent seasonal variation in pulmonary embolism than deep vein thrombosis incidence: a Korean venous thrombosis epidemiology study

BACKGROUND/AIMS

Seasonal variation is an environmental factor proposed to affect the incidence of venous thromboembolism (VTE). However, VTE seasonal variation is not well studied in Asian populations, which have different genetic determinants of VTE compared to Westerners. The present study aimed at investigating seasonal variation of VTE occurrence and the effect of various demographic factors (i.e., age, sex, and co-morbidities) on variation.

METHODS

VTE seasonal variation was evaluated in 59,626 index cases (from January 2009 to December 2013) in the Korean Health Insurance Review and Assessment Service database. We quantified and compared VTE occurrence across four seasons, and additionally assessed monthly through a chronobiological analysis.

RESULTS

VTE incidence varied both seasonally and monthly, with new cases peaking in the winter (January and February) and the lowest incidence in the summer (August and September). After adjusting for sex, age, type of VTE, and combined cancer diagnosis, winter remained a significant independent factor driving VTE incidence. Additionally, seasonal variation was prominent in patients aged 60 years or older and in patients with pulmonary embolism, but not so prominent in patients of aged less than 60 years and patients with deep vein thrombosis.

CONCLUSION

Seasonal variation was a weak but independent contributor to VTE incidence in a Korean population diagnosed from 2009 to 2013, especially in those individuals with old age or suffering from a pulmonary embolism.

Risk Factor and Mortality in Patients with Pulmonary Embolism Combined with Infectious Disease

BACKGROUND

Infectious conditions may increase the risk of venous thromboembolism. The purpose of this study was to evaluate the risk factor for combined infectious disease and its influence on mortality in patients with pulmonary embolism (PE).

METHODS

Patients with PE diagnosed based on spiral computed tomography findings of the chest were retrospectively analyzed. They were classified into two groups: patients who developed PE in the setting of infectious disease or those with PE without infection based on review of their medical charts.

RESULTS

Of 258 patients with PE, 67 (25.9%) were considered as having PE combined with infectious disease. The sites of infections were the respiratory tract in 52 patients (77.6%), genitourinary tract in three patients (4.5%), and hepatobiliary tract in three patients (4.5%). Underlying lung disease (odds ratio [OR], 3.69; 95% confidence interval [CI], 1.926-7.081; p<0.001), bed-ridden state (OR, 2.84; 95% CI, 1.390-5.811; p=0.004), and malignant disease (OR, 1.867; 95% CI, 1.017-3.425; p=0.044) were associated with combined infectious disease in patients with PE. In-hospital mortality was higher in patients with PE combined with infectious disease than in those with PE without infection (24.6% vs. 11.0%, p=0.006). In the multivariate analysis, combined infectious disease (OR, 4.189; 95% CI, 1.692-10.372; p=0.002) were associated with non-survivors in patients with PE.

CONCLUSION

A substantial portion of patients with PE has concomitant infectious disease and it may contribute a mortality in patients with PE.

Safety of early orthopedic surgery in patients with intermediate/low- or low-risk pulmonary embolism

Background

Preoperative pulmonary embolism (PE) is one of the comorbidities in patients with hip fracture. However, previous studies have not identified the optimal timing of surgery in these patients, who might require early surgery. This study aimed to investigate the safety and clinical feasibility of early surgery in patients with hip fracture and acute PE.

Methods

The medical records of 156 patients with hip fracture, who were suspected to have PE and underwent pulmonary computed tomography angiography at Asan Medical Center from January 2008 to December 2017, were retrospectively reviewed. After excluding patients who were diagnosed with PE during the postoperative period, the baseline characteristics and clinical course were compared between patients preoperatively diagnosed with PE (PE group) and patients without PE during the hospital stay (non-PE group). Adverse outcomes were evaluated during 3 months postoperatively.

Results

The baseline characteristics were not different between the PE group (n=90) and the non-PE group (n=50). All patients in the PE group were classified as having an intermediate/low or low risk according to the European Society of Cardiology guidelines and underwent surgery within 30 days after the PE diagnosis (median duration: 2 days). None of the patients in both groups developed symptomatic venous thromboembolism (VTE) during the follow-up. Moreover, there were no statistically significant differences in major bleeding, clinically relevant nonmajor (CRNM) bleeding, transfusion amount, bleeding site, and length of hospital stay between the PE and non-PE groups.

Conclusions

Our results suggest that early surgery might be a reasonable treatment option in patients with hip fracture and acute PE.

Changing Treatment Patterns in Patients With Venous Thromboembolism in Taiwan

BACKGROUND

In Asia, little information is available about contemporary real-world treatment patterns for venous thromboembolism (VTE).Methods and Results:Consecutive patients (n=11,414) from the Taiwan National Health Insurance Research Database with initial VTE and taking oral anticoagulants between May 1, 2014 and June 30, 2016 were included. The temporal trends of using oral anticoagulants and pharmacomechanical therapy during the study period were evaluated. The efficacy and safety of nonvitamin K antagonist oral anticoagulants (NOACs) vs. warfarin were compared. Propensity score analysis (NOACs n=3,647 vs. warfarin n=3,647) was used to balance covariates between groups, and Cox proportional hazards models with adjustment were used to estimate the risks of clinical outcomes. The use of NOACs increased from 0.3% to 60.2% for VTE treatment during the study period. Pharmacomechanical therapy was used in 9.60%, 8.22%, and 5.63% from 2014 through 2016. NOACs were associated with a 16% risk reduction (adjusted hazard ratio [aHR] 0.84, 95% confidence interval [CI] 0.77-0.93) in all-cause mortality and a 21% risk reduction (aHR 0.79, 95% CI 0.65-0.96) in recurrent VTE vs. warfarin. Overall, NOACs were associated with a lower risk of major bleeding compared with warfarin (aHR 0.804, 95% CI 0.648-0.998).

CONCLUSIONS

In real-world practice, NOACs have become the major anticoagulant used for Asians with VTE. Although NOACs had a lower risk of recurrent VTE and major bleeding compared with warfarin in Taiwan, we still need a large-scale randomized controlled trial to confirm the findings.

Venous Thromboembolism in Children and Young Adults in Korea: Analysis of the Korean Health Insurance Review and Assessment Service Database

BACKGROUND

Venous thromboembolism (VTE) is very rare in childhood. Nevertheless, its incidence has increased recently. This study aimed to identify risk factors for developing thrombosis in childhood cancers and other childhood diseases through the Korean Health Insurance Review and Assessment Service database.

METHODS

Data were extracted from the Korean Health Insurance Review and Assessment Service database. Children and young adults from 1 month to 29 years of age were eligible, and 21,747 cases of VTE between January 2008 and December 2016 were identified.

RESULTS

The VTE incidence was high in children younger than 1 year of age. After 1 year of age, its incidence decreased rapidly and gradually increased. The VTE incidence for children between 0 and 1 year of age was 10.23-fold higher than that for those between 1 and 5 years of age. Annual VTE incidence increased by year. The age-standardized annual incidence rates were 9.98 per 100,000 population in 2008 and 22.53 per 100,000 population in 2016. The age-standardized annual incidence rate increased 2.25-fold during the 8 years. The lower extremity was the most common site of venous thrombosis.

CONCLUSION

The incidence of VTE in a population younger than 30 years was 13.11 per 100,000 persons in Korea. We found a bimodal age distribution of the VTE incidence with peaks at infancy and again after 16 years. The incidence of portal vein thrombosis was high in infants, and infection and malignancy were the most common comorbidities in patients with VTE.

Incidence and characteristics of venous thromboembolism in Asian patients with primary central nervous system lymphoma undergoing chemotherapy

BACKGROUND

Venous thromboembolism (VTE) may lead to diminished quality of life and ultimately worse prognosis in cancer patients, but there is limited data on the incidence, risk factors and mortality impact of VTE in Asian primary central nervous system lymphoma (PCNSL) patients.

OBJECTIVES

To report the incidence, risk factors and mortality impact of VTE in Asian PCNSL patients.

METHODS

From 7 academic centers in Korea, 235 newly diagnosed PCNSL patients undergoing chemotherapy were retrospectively identified during period of January 2004 to September 2018.

RESULTS

All patients but 12 (6 T-cell, 6 other B-cell) had diffuse large B-cell lymphoma. During the median follow-up of 21 months, 33 patient (14.0%) developed VTE. Of the VTE events, 11 (33.3%) were deep vein thrombosis (DVT), 15 (45.5%) were pulmonary thromboembolism (PTE), and 7 (21.2%) were DVT with PTE. The median time to VTE was 2 months and the one-year actuarial incidence was 11.7%. On multivariate analysis, ECOG performance ≥2, age >60 years, female sex, and Hb <10 g/dL were independently associated with VTE. The patients with VTE were associated with shorter disease specific survival (P = 0.046) and overall survival (P = 0.022).

CONCLUSION

Overall, the incidence of VTE in Asian PCNSL seems to be lower compared to Western population. As VTE development is associated with overall survival and indicative of relapse, careful close monitoring is warranted.

Using non-vitamin K oral anticoagulants in specific patient populations: a study of Korean cases

Non-vitamin K oral anticoagulants (NOACs) are increasingly used as alternatives to conventional therapies and have considerable accumulated real-world clinical data in patients with non-valvular atrial fibrillation (NVAF) or venous thromboembolism (VTE). However, it is not easy to make a complete changeover to NOACs in real-world clinical practice because NOACs still have challenges in specific patient populations (eg, Asian patients, NVAF patients presenting with acute coronary syndrome [ACS], dialysis patients with NVAF, patients with cancer-associated VTE, etc.). Clinical data on the optimal dose of NOACs in Asian patients with NVAF are not sufficient. The intensity of NOAC and antiplatelet treatment and the duration of antiplatelet treatment should be adjusted according to the bleeding and thrombotic risk profiles of the individual NVAF patient presenting with ACS. Increased bleeding risk and unclear efficacy of NOACs in dialysis patients with NVAF should be considered when making decisions on whether to give NOACs for these patients. If dialysis patients with NVAF require anticoagulant for stroke prevention, then apixaban could be considered while awaiting more clinical efficacy and safety data. Additional studies are needed to determine the utility of continuing treatment with reduced-dose NOACs for long-term therapy after VTE. We have enough experiences in using NOACs in cancer patients showing the benefit of antithrombotic treatment counterbalanced the bleeding risk; however, some challenges of cancer-associated VTE management exist due to differences in cancer types or chemotherapy regimens and comorbidities. Different dosing regimens among NOACs may impact on medication adherence; thus, individual patient preference should be considered in choosing a particular NOAC. A significant proportion of patients remain on warfarin because of the high price of NOACs and variability in reimbursement coverage. To compensate clinical-evidence and achieve optimal use of NOACs, we should pay attention to the outcomes of ongoing studies and evaluate more real-world data.

Analysis of the Association Between MicroRNA Biogenesis Gene Polymorphisms and Venous Thromboembolism in Koreans

Venous thromboembolism (VTE) involves the formation of a blood clot, typically in the deep veins of the leg or arm (deep vein thrombosis), which then travels via the circulatory system and ultimately lodges in the lungs, resulting in pulmonary embolism. A number of microRNAs (miRNAs) are well-known regulators of thrombosis and thrombolysis, and mutations in miRNA biogenesis genes, such as DICER1, DROSHA have been implicated in miRNA synthesis and function. We investigated the genetic association between polymorphisms in four miRNA biogenesis genes, DICER1 rs3742330A > G, DROSHA rs10719T > C, RAN rs14035C > T and XPO5 rs11077A > C, and VTE in 503 Koreans: 300 controls and 203 patients. Genotyping was assessed with polymerase chain reaction-restriction fragment length polymorphism assays. We detected associations between polymorphisms in RAN and XPO5 and VTE prevalence (RAN rs14035CC + CT versus TT: p = 0.018; XPO5 rs11077AA + AC versus CC: p < 0.001). Analysis of allele combinations of all four polymorphisms (DICER1, DROSHA, RAN, XPO5) revealed that A-T-T-A was associated with decreased VTE prevalence (p = 0.0002), and A-T-C-C was associated with increased VTE prevalence (p = 0.027). Moreover, in subjects with provoked VTE, the DROSHA rs10719T > C, polymorphism was associated with increased disease prevalence (TT versus TC + CC: p < 0.039). Our study demonstrates that RAN and XPO5 polymorphisms are associated with risk for VTE in Korean subjects.

Incidence and Risk Factors of Recurrent Venous Thromboembolism after Pulmonary Embolism

Background

Information about the epidemiology of venous thromboembolism (VTE) recurrence in Korea is lacking. The purpose of this study was to investigate VTE cumulative recurrence rates and identify risk factors for VTE recurrence among Korean adults.

Methods

A retrospective cohort study was conducted on adult patients (≥18 years) admitted to a university teaching hospital for pulmonary embolism (PE) from 2005 to 2013. The main outcome of interest was a recurrence of VTE. We used Cox proportional hazard regression analyses to calculate the relative risk of VTE recurrence.

Results

Five-year cumulative incidence of recurrent VTE events was 21.5% (95% confidence interval [CI], 17.7–25.4) in all cases of PE; 17% after provoked and 27% after unprovoked PE. Multivariate analysis showed that body mass index (BMI) of ≥25 (hazard ratio [HR], 2.02; 95% CI, 1.17–3.46; p=0.01) and longer anticoagulation therapy duration (HR, 0.90; 95% CI, 0.84–0.96; p<0.01) were independently associated with risk of VTE recurrence. Risk factors not found to be statistically significant at the <0.05 level included history of VTE (HR, 1.81; 95% CI, 0.84–3.88; p=0.12), unprovoked PE (HR, 1.70; 95% CI, 0.89–3.25; p=0.10), symptomatic deep vein thrombosis (HR, 1.62; 95% CI, 0.89–2.94; p=0.10), and female sex (HR, 1.42; 95% CI, 0.78–2.55; p=0.24). We found that age, history of cancer, and other co-morbidities did not significantly affect the risk of VTE recurrence.

Conclusion

Recurrence of VTE after PE is high. Patients with BMI ≥25 or reduced anticoagulation therapy duration have a higher risk of recurrent VTE.

Knowledge, Awareness and Risk of Occurrence of Venous Thromboembolism of Perinatal Women

PURPOSE

The purpose of this study is to identify knowledge, awareness, and risk of occurrence of venous thromboembolism among pregnant women.

METHODS

Subjects were 106 pregnant women treated as inpatients and outpatients at a women's health hospital in a metropolitan city February 19-March 22, 2018. Instruments consisted of questionnaires that included knowledge, awareness, and risk of occurrence of venous thromboembolism queries. Collected data were analyzed by t-test, one-way analysis of variance, Mann-Whitney U test and Kruskal-Wallis test.

RESULTS

Mean score of subjects' knowledge of venous thromboembolism was 4.47 (0-15), mean score of subjects' awareness of venous thromboembolism was 66.98 (25-100), and mean score of subjects' risk factor of venous thromboembolism was 0.98 (0-44). CONCLUSIONS: Pregnant women's level of knowledge and awareness of prevention and risk factors on venous thromboembolism, is significantly low. To raise their awareness of risk symptoms and prevent occurrence of the disease, it is essential for nurses as well as medical staffs to: 1) provide an educational program on venous thromboembolism for patients; 2) assess and monitor pregnant women with a risk factor of venous thromboembolism; and 3) implement proper prophylaxis for patients.

Association of TFPI polymorphisms rs8176592, rs10931292, and rs10153820 with venous thrombosis: A meta-analysis

BACKGROUND

Tissue factor pathway inhibitor (TFPI) polymorphisms are known to be involved in venous thrombosis; however, any correlation between the TFPI polymorphisms rs8176592, rs10931292, and rs10153820 and venous thrombosis remains controversial. This meta-analysis aimed to elucidate the relationship between these TFPI polymorphisms and the susceptibility to venous thrombosis.

METHODS

A literature search for relevant studies was conducted in PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), and Wanfang Med Online databases. Odds ratios (ORs) and their corresponding 95% confidence intervals (95% CIs) were calculated using fixed-effect/random-effect models by the STATA 12.0 software. Sources of heterogeneity were analyzed by subgroup analysis.

RESULTS

Eleven case-control studies involving 3740 subjects (1362 venous thrombosis patients and 2378 healthy controls) were included. The TFPI rs8176592 polymorphism was associated with increased risk of venous thrombosis in the whole population, while no significant association was found between rs10931292/rs10153820 and venous thrombosis. In subgroup analysis based on ethnicity, an increased risk was observed with rs8176592 polymorphism in Asians (Recessive model, OR = 1.48, 95% CI = 1.06-2.07, P = .023). An increased risk associated with rs10931292 was identified in non-Asians (Recessive model, OR = 1.42, 95% CI = 1.03-1.97, P = .033). No significant association was found in either Asians or non-Asians with the rs10153820 polymorphism. In subgroup analysis based on source of controls, increased risks were identified in the hospital-based group with rs8176592 polymorphism and in the population-based group with rs10931292 polymorphism, whereas decreased risk was identified in the hospital-based group with the rs10931292 and rs10153820 polymorphisms.

CONCLUSION

Meta-analysis suggested that different TFPI polymorphisms may have different associations with venous thrombosis. TFPI rs8176592 polymorphism may increase the risk of venous thrombosis, especially in Asians and hospital-based patients. The TFPI rs10931292 polymorphism may increase the venous thrombosis risk for both non-Asians and population-based patients. Moreover, rs10931292 and rs10153820 polymorphisms of TFPI may decrease the risk of venous thrombosis for hospital-based patients.

Current Management of Cancer-associated Venous Thromboembolism: Focus on Direct Oral Anticoagulants

Cancer-associated venous thromboembolism (CAT) is a common complication associated with high morbidity and mortality. In accordance with major clinical trials comparing low-molecular-weight heparin (LMWH) with a vitamin K antagonist (VKA), LMWH is currently the standard treatment for CAT, owing to its efficacy for thrombosis recurrence and improved safety profile compared to VKA. Over the past few years, direct oral anticoagulants (DOACs) have emerged as potential alternative therapies to LMWH due to their convenient route of administration and predictable pharmacokinetics, but evidence for their use in CAT is inconclusive, as only a small fraction of the study populations in these trials had CAT. Recently, two large head-to-head trials comparing DOACs to LMWH in CAT patients reported comparable efficacies of DOACs with increased bleeding risk. Occasionally, CAT treatment can be challenging due to the heterogeneity of underlying malignancies and comorbidities. Renal insufficiency and gastrointestinal defects are the main obstacles in anticoagulant selection. Careful choice of treatment candidates and proper anticoagulant strategies are critical for the treatment of CAT; hence, more studies are required to address these challenges.

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.

Incidence and predictors of venous thromboembolism in medically ill hospitalized elderly cancer patients: a prospective observational study

PURPOSE

The aim of this study was to estimate the incidence and predictors of venous thromboembolism (VTE) in medically ill hospitalized elderly cancer patients in a single Korean tertiary hospital.

METHODS

Patients were examined for deep vein thrombosis (DVT) by duplex and color Doppler ultrasonography (DUS) of both legs between days 5 and 14 of their hospital stays. The primary endpoint was the incidence of VTE by day 14, which was determined via a composite of DVT detected by routine DUS and symptomatic VTE.

RESULTS

A total of 140 patients with 31 hematologic and 109 nonhematologic malignancies were analyzed. The median age was 73 years, and 45.7% of the patients were female. The median length of hospital stay was 12 days. The modified Padua prediction score (PPS) ≥ 4 was 92.9%. The incidence of VTE by day 14 was 7.1%, including six proximal and four distal DVT cases. Being female, having a length of hospital stay of ≥ 13 days, and having a modified Padua prediction score of ≥ 6 were risk factors of VTE in univariate analysis. The incidence of VTE was 2.3%, 7.3%, and 41.7% in patients with 0-1, 2, and 3 of these risk factors, respectively.

CONCLUSION

The incidence of VTE in medically ill hospitalized elderly cancer patients was lower in Korean patients than in Western patients. However, the risk of VTE in those with more than two risk factors (female, long length of hospitalization, and high PPS) increased considerably, and pharmacologic thromboprophylaxis is warranted in these cases.