Venous Thromboembolism In Korean Patients Research Articles

P1137 Long-term trend of cumulative incidence of venous thromboembolism in Korean patients with inflammatory bowel disease: A nationwide population-based cohort study

Abstract Background Venous thromboembolism (VTE) is a serious extraintestinal manifestation of inflammatory bowel disease (IBD). However, limited research has been conducted on the cumulative incidence of VTE in patients with IBD. Therefore, this study aimed to observe the trend of cumulative incidence of VTE after IBD diagnosis. Methods From 2005 to 2016, a population-based cohort study was conducted using health administration claims data from South Korea. IBD and VTE were defined by ICD-10 codes. Incidence density and cumulative incidence rate were analysed. The risk of variables including age, sex, and IBD subtype was comparatively analysed. Results A total of 35,508 newly diagnosed patients with IBD between 2005 and 2015 were followed up until 2016. Among them, 634 (1.8%) experienced VTE (619 adults and 15 children). The incidence densities of VTE per 10,000 person-year were 28.90 (range, 27.75–32.54) for overall IBD, 30.07 (range, 27.75–32.54) for adult IBD, and 11.08 (range, 6.20–18.27) for PIBD, respectively. The cumulative incidences of VTE at 0, 1-, 3-, 5-, and 10 years post-diagnosis were 0.01%, 0.30%, 0.80%, 1.30%, and 3.0%, respectively (Figure 1-A). Adulthood, female sex, and ulcerative colitis were associated with an increased risk of VTE (Figure 1-B, C, D). Conclusion The study showed a steady and gradual increase in the cumulative incidence of VTE in patients with IBD over a follow-up period of up to 11 years, with a slightly more rapid increase after 8 or 9 years. This trend was even more pronounced in children. This suggests that vigilant monitoring of VTE is necessary in the management of patients with IBD.

The Risk of Venous Thromboembolism in Korean Patients with Breast Cancer: A Single-Center Experience.

The relationship between cancer and venous thromboembolism (VTE) has long been described. The risk of VTE in Asian patients with breast cancer remains largely unknown. This study described the incidence and risk factors of VTE in Korean patients with breast cancer. Data were collected from a retrospective database of patients who underwent breast cancer surgery between 2011 and 2020 at a single institution. The Cox proportional-hazards model was used to identify factors associated with VTE occurrences. Among the 2246 patients with breast cancer, 48 (2.1%) developed VTE during a median follow-up period of 53 months. The average incidence of VTE was 459 per 100,000 person-years. Age ≥ 60 years, male sex, chronic kidney disease, reconstructive procedures, and stage II or higher were independent predictive factors for VTE. VTE was associated with poor disease-free survival (hazard ratio (HR), 6.140; 95% confidence interval (CI), 3.480-10.835), and overall survival (HR, 8.842; 95% CI 4.386-17.824). Most VTE events were manageable with anticoagulation; three (6.3%) patients died of VTE, despite intensive care. The incidence of VTE was significantly elevated in Korean patients with breast cancer. Since VTE has a negative effect on oncologic outcomes of breast cancer, clinicians should manage its risk throughout their lifetime.

Risk of venous thromboembolism in Korean patients with rheumatoid arthritis treated with Janus kinase inhibitors: A nationwide population-based study

There was a safety concern about an increased risk of thromboembolic events in patients with rheumatoid arthritis (RA) treated with Janus kinase inhibitors (JAKis). This study aimed to determine the risk of venous thromboembolism (VTE) in Korean patients with RA treated with JAKis compared with tumour necrosis factor (TNF) inhibitors. Using the National Health Insurance Service database between 2015 and 2019, patients with prevalent RA who started JAKi or TNF inhibitor were selected as the study population. All participants were naïve to targeted therapy. Patients that had experienced any VTE event or used anticoagulant agents within 30 days were excluded. Demographic and clinical characteristics were all balanced by stabilised inverse probability of treatment weighting (sIPTW) using propensity score. The Cox proportional hazard model considering death as a competing risk was used to evaluate the risk of VTE in JAKi users compared with TNF inhibitor users. A total of 4,178 patients were included: 871 JAKi users and 3,307 TNF inhibitor users were followed up for 1,029.2 person-years (PYs) and 5,940.3 PYs, respectively. With a balanced sample after sIPTW, the incidence rates (IR) of VTE were 0.06 per 100 PYs (95% confidence interval [CI] 0.00-1.23) in JAKi users and 0.38 per 100 PYs (95% CI 0.25-0.58) in TNF inhibitor users. The hazard ratio was 0.18 (95% CI 0.01-3.47) after adjusting for unbalanced variables after performing sIPTW. There is no increased risk of VTE in RA patients treated with JAKis compared with TNF inhibitors in Korea.

Characteristics and Effect of Rivaroxaban on Venous Thromboembolism in Korean Patients Compared to Western Population: A Subgroup Analysis from XALIA(-LEA) Study.

This study aimed to compare the characteristics of venous thromboembolic disease (VTE) in Korean to Caucasian population. XALIA-LEA and XALIA were phase IV non-interventional prospective studies with identical designs that investigated the effect of rivaroxaban versus standard anticoagulation for VTE. Koreans accounted for the largest proportion of the overall enrolled population of XALIA-LEA. However, in the XALIA study, most patients were Caucasian. Therefore, Korean data from XALIA-LEA and Caucasian data from XALIA were used in this study. This study compared the clinical characteristics and primary outcomes of the XALIA program, including major bleeding, recurrent VTE, and all-cause mortality. The Korean population was older, was less obese, and had more active cancer at baseline than the Caucasian population. Provoked VTE was more common in the Korean population. Interestingly, Koreans showed less accompanying thrombophilia than Caucasians, and factor V Leiden mutations were not detected. Korean analyses comparing the effects of rivaroxaban and standard anticoagulation with primary outcomes showed a lower incidence of major bleeding, recurrent VTE, and all-cause mortality with rivaroxaban. Similar results were obtained in the propensity score matching analysis. Characteristic differences were found between Korean and Caucasian VTE patients. Despite these ethnic differences, the effectiveness and safety of rivaroxaban therapy in these patients were consistent.

P799 Use of anti-TNF agents may reduce a risk of venous thromboembolism in Korean patients with inflammatory bowel disease: A nationwide population-based study from the National Health Insurance Database

Abstract Background Inflammatory bowel disease (IBD) has a risk of venous thromboembolism (VTE) compared with healthy controls, which justify prophylaxis in practice. There are few data on VTE in Asian IBD patients including Koreans. We aimed to investigate the incidence of VTE and the potential risk factors in Korean IBD patients. Methods A nationwide population-based cohort study was performed using claims data from the National Health Insurance service in Korea for 10 years, from 2006 to 2015. VTE, Crohn’s disease (CD) and ulcerative colitis (UC) were operationally defined by using ICD-10 codes, codes for Rare and Intractable Diseases registration, and pharmaceutical prescriptions for IBD-specific drugs. Control group was defined as age- and sex-matched health insurance subscribers without IBD for the same period. The hazard ratio (HR) for the risk of VTE was calculated after adjusting for covariates such as age, sex, rural area, comorbidities, Charlson Comorbidity Index (CCI), admission, and therapeutic drugs use for IBD using multivariate Cox proportional hazard regression. Results A total of 45,037 patients were diagnosed with IBD (13,850 CD and 31,187 UC), and 133,019 were defined as controls. VTE occurred in 411 (0.91%) in IBD, 106 (0.76%) in CD, and 305 (0.98%) in UC, whereas 641 (0.48%) in controls. In univariate analysis among IBD patients, old age (>59 years: HR = 6.256), female sex (HR = 1.537), low income (HR = 1.3090), high CCI (>3 score: HR = 4.053), steroid use (HR = 1.872), emergency care (HR = 1.513) and hospitalisation (HR = 1.352) significantly increased a risk of VTE. However, anti-TNF agent use (HR = 0.611) significantly decreased a risk of VTE. In multivariate analysis with adjustment among all subjects, CD (HR = 15.833) and UC (HR = 8.125) significantly increased a risk of VTE compared with controls. Conclusion Our study demonstrates that VTE is significantly high in Korean IBD patients compared with controls. In addition, old age, female sex, low income, high CCI, steroid use, emergency care, and hospitalisation are suggested as risk factors of VTE in IBD. Interestingly, use of anti-TNF agents may reduce risk of VTE, which should be considered for prophylaxis strategy suitable for Korean IBD patients.

Association study of miR-146a, miR-149, miR-196a2, and miR-499 polymorphisms with venous thromboembolism in a Korean population.

Despite much progress in microRNA (miRNA) research, information regarding the association between miRNAs and venous thromboembolism (VTE), especially in Asian patients, remains limited. This case-control study sought to determine the correlation between the presence of polymorphisms in the genes encoding the miRNAs miR-146a, miR-149, miR-196a2, miR-499, and VTE in Korean patients. We observed no statistically significant differences in the genotype frequency of miRNA polymorphisms between 300 control individuals and 203 VTE patients. However, we observed a significant association between three allelic combinations of miRNA polymorphisms and VTE risk. Overall, our findings suggest that specific miRNA polymorphisms are associated with the risk of VTE in a Korean population.

Venous Thromboembolism Incidence and Prophylaxis Use After Gastrectomy Among Korean Patients With Gastric Adenocarcinoma

The guidelines by the National Comprehensive Cancer Network and the American Society for Clinical Oncology recommend the routine use of thromboprophylaxis for patients with gastric adenocarcinoma. However, many physicians in Asian countries use venous thromboembolism (VTE) prophylaxis much less often because of the perceived lower VTE incidence in this population. To evaluate the incidence of postgastrectomy VTE in Korean patients with gastric adenocarcinoma, and to identify the complications and evaluate the efficacy and safety of VTE prevention methods. The Optimal Prophylactic Method for Venous Thromboembolism After Gastrectomy in Korean Patients (PROTECTOR) randomized clinical trial was conducted between August 1, 2011, and March 31, 2015. Patients with histologically confirmed gastric adenocarcinoma presenting to a single center (Seoul St Mary's Hospital in Seoul, South Korea) were enrolled. Patients were randomized to either an intermittent pneumatic compression (IPC)-only group or an IPC+low-molecular-weight (LMW) heparin sodium group. The data were analyzed on intention-to-treat and per protocol bases. Data analysis was performed from April 1, 2016, to October 30, 2017. Venous thromboembolism incidence was the primary outcome. Postoperative complications, particularly those associated with VTE prophylaxis methods, were the secondary end point. Of the 682 patients enrolled and randomized, 447 (65.5%) were male and 245 (34.5%) were female, with a mean (SD) age of 57.67 (12.94) years. Among the 666 patients included in the analysis, the overall incidence of VTE was 2.1%. The incidence of VTE was statistically significantly higher in the IPC-only group compared with the IPC+LMW heparin group (3.6%; 95% CI, 2.05%-6.14% vs 0.6%; 95% CI, 0.17%-2.18%; P = .008). Among the 14 patients (2.1%) with VTE, 13 were asymptomatic and received a deep vein thrombosis diagnosis, whereas 1 patient received a symptomatic pulmonary thromboembolism diagnosis. The overall incidence of bleeding complications was 5.1%. The incidence of bleeding complications was significantly higher in the IPC+LMW heparin group compared with the IPC-only group (9.1% vs 1.2%; P < .001). No cases of VTE-associated mortality were noted. Use of IPC alone is inferior to the use of IPC+LMW heparin in preventing postoperative VTE. Because LMW heparin is associated with a high bleeding risk, further study is needed to stratify the patients at high risk for perioperative development of VTE. ClinicalTrials.gov Identifier: NCT01448746.

Prevalence and Risk Factor of Venous Thromboembolism in Korean Patients with Congestive Heart Failure

Prevalence and Risk Factor of Venous Thromboembolism in Korean Patients with Congestive Heart Failure

Pharmacological thromboprophylaxis and its impact on venous thromboembolism following total knee and hip arthroplasty in Korea: A nationwide population-based study.

BackgroundLimited data is available regarding the pharmacological prophylaxis for venous thromboembolism (VTE) in Asian patients undergoing total knee arthroplasty or total hip arthroplasty (TKA/THA).MethodsWe performed a population-based epidemiological study using the Health Insurance Review and Assessment Service database to estimate the rate of pharmacological thromboprophylaxis and its impact on VTE in Korean patients who underwent TKA/THA between 2009 and 2013.ResultsWe identified 306,912 cases (TKA, 261,260; THA, 45,652). The pharmacological thromboprophylaxis rate was 57.16% (TKA, 58.32%; THA, 50.51%), which increased from 42.81% in 2009 to 65.92% in 2013 (P = 0.0165). Both low-molecular-weight-heparin (22.42%) and rivaroxaban (22.71%) were the most common drugs for prophylaxis. The number of patients aged ≥ 60 years (87.31% vs. 81.01%, P < 0.0001), cases requiring general anesthesia (20.70% vs. 18.37%, P < 0.0001), and cases requiring long hospital stay (median, 13 days vs. 12 days, P < 0.0001) were significantly greater in the pharmacological prophylaxis group. The incidence of VTE within 3 months of surgery was 1.52% (TKA, 1.46%; THA, 1.87%). Patients with pharmacological prophylaxis had higher VTE rates (TKA, 1.69% vs. 1.14%; THA, 2.30% vs. 1.43%) than those without prophylaxis, with advanced age, use of general anesthesia, and a longer hospital stay increasing the risk of VTE. However, rivaroxaban significantly reduced the incidence of VTE following TKA (0.82% vs. 1.14%; odd ratio [OR], 0.72; 95% CI, 0.65–0.79). Moreover, ≥ 10 days of pharmacological thromboprophylaxis was significantly associated with lower incidence of VTE after TKA (1.33% vs. 1.52%; OR, 0.87; 95% CI, 0.81–0.94).ConclusionThis represents the largest epidemiological study showing a gradual increase in the use of pharmacological prophylaxis in Korean patients undergoing TKA/THA. Although the incidence of VTE is still low without pharmacological prophylaxis, this study demonstrates that the incidence of VTE can be reduced further using appropriate pharmacological thromboprophylaxis strategies.

The Efficacy of Low Molecular Weight Heparin for the Prevention of Venous Thromboembolism after Hip Fracture Surgery in Korean Patients.

PurposeThe aim of this study was to investigate the efficacy of low-molecular-weight heparin (LMWH) for the prevention of venous thromboembolism in Korean patients who underwent hip fracture surgery (HFS).Materials and MethodsProspectively, a total 181 cases were classified into the LMWH user group (116 cases) and LMWH non-user group (65 cases). Each group was sub-classified according to fracture types as follows: 81 cases of intertrochanteric fracture (group A: 49, group B: 32) and 100 cases of neck fracture (group C: 67, group D: 33). We compared the incidence of deep vein thrombosis (DVT) and pulmonary embolism (PE) according to LMWH use.ResultsOf the 181 cases, four DVTs were found in the LMWH user groups (1 in group A, and 3 in group C). One case of PE was found in LMWH non-user group D. The incidences of DVT and PE showed no statistically significant differences between the LMWH user and non-user groups (p=0.298 and 0.359, respectively). In subgroup analysis, no statistically significant differences were found between groups A and B and between groups C and D.ConclusionThe administration of LMWH was not effective in the prevention of venous thromboembolism and PE in the Korean patients who underwent HFS.

Venous Thromboembolism Following L-Asparaginase Treatment in Hematologic Malignancies in Korea

Background: L-asparaginase (L-asp) is one of the important drugs to make the change of cure higher in acute lymphocytic leukemia (ALL) and some lymphomas. The risk of thrombosis in ALL patients after L-asp use is known to be 2.4-5.4% in pediatric and 5.9-34% in adult. Although the prevalence of venous thromboembolism (VTE) in Asian is generally lower compared with Western populations, there are few reports about the incidence of VTE in Asian patients with hematologic malignancies treated with L-asp. In this study we performed a nationwide population-based epidemiologic study to provide basic information regarding the incidence rate and risk factors of VTE in Korean patients with hematologic malignancies after L-asp treatment.Methods: Using the Korean Health Insurance Review and Assessment Service (HIRA) database, patients treated with L-asp from 2009 to 2013 were retrospectively identified by medication codes. The National Health Insurance (NHI) is the only public medical insurance system operated by the Ministry for Health, Welfare and Family Affairs in Korea. The NHI program of Korea covers the whole population as a compulsory social insurance system. Therefore, there are no exceptions for seasonal, part-time or unemployed workers. HIRA is a government-affiliated organization to build an accurate claims review and quality assessment system for the NHI. According to data from the Korean Statistical Information Service (http://kosis.kr/) the Korean population was 48 580 293 in 2010. Also, according to data from the NHI, the registered populations was 50 581 000 in 2010. There is a difference in population figures between data from the Korean National Statistical Office and the NHI because of overseas Koreans. A population-based study was possible for this study because the NHI basically covers all Korean residents and also the population itself is ethnically homogeneous. The HIRA database includes both hospitalization cases and outpatient clinic cases. All cases were included in the study when there was evidence of L-asp treatment. Among the cases with L-asp, VTE cases which has occurred after L-asp treatment were identified when the starting date of the VTE diagnostic codes was between the start date of L-asp and 3 months after the end of L-asp treatment.Results: During the year 2009 to 2013, a total of 3304 patients were prescribed with colaspase in any type of hematologic malignancies including ALL and lymphoma. Patients who were treated with pegarspase or crisantaspase were not included. Among the 3304 patients, 118 patients (3.57%) had occurred VTE. The most common site of thrombosis was upper extremities (44/118 = 37.29%) followed by deep vein (30/118 = 25.42%) and pulmonary artery (30/118 = 25.42%), inferior vena cava (6/118 = 5.08%), portal vein (3/118 = 2.54%), cerebral sinus (2/118 = 1.69%), renal vein (2/118 = 1.69%), and splenic vein (1/118 = 0.85%). Among the 1809 patients 18 years or younger, 37 patients (2.05%), and among the 1501 patients 19 years of older, 81 patients (5.39%) suffered from VTE (P < 0.0001). Other factors including gender, disease (ALL or lymphoma), type of steroids (prednisone or dexamethasone) and use of anthracyclines did not appear to be associated with VTE after L-asp treatment.Conclusions: This is the largest epidemiologic study in Asian patients with hematologic malignancies with L-asp treatment. The incidence of thrombosis after L-asp use was comparable with Western populations, and the risk was higher in adults compared with pediatrics. Concomitant use of prednisone and anthracyclines did not affect VTE occurrence. DisclosuresNo relevant conflicts of interest to declare.

Occurrence and Prognosis of Symptomatic Venous Thromboembolism in Colorectal Cancer Surgery Patients.

Purpose:Colorectal cancer (CRC) has a high risk for postoperative thromboembolic complications such as venous thromboembolism (VTE) compared to other surgical diseases, but the relationship between VTE and CRC in Asian patients remains poorly understood. The present study examined the incidence of symptomatic VTE in Korean patients who underwent surgery for CRC. We also identified risk factors, incidence and survival rate for VTE in these patientsMaterials and Methods:The patients were identified from the CRC database treated from January 2011 to December 2012 in a single institution. These patients were classified into VTE and non-VTE groups, their demographic features were compared, and the factors which had significant effects on VTE and mortality between the two groups were analyzed.Results:We analyzed retrospectively a total of 840 patients and the incidence of VTE was 3.7% (31 patients) during the follow-up period (mean, 17.2 months). Histologic subtype (mucinous adenocarcinoma) and previous history of VTE affected the incidence of VTE on multivariate analysis. There was a statistically significant difference in survival rate between the VTE and non-VTE group, but VTE wasn’t the factor affecting survival rate on multivariate analysis. Comparing differences in survival rate for each pathologic stage, there was only a significant difference in stage II patients.Conclusion:Among CRC patients after surgery, the incidence of VTE was approximately 3% within 1 year and development of VTE wasn’t a significant risk factor for death in our study but these findings are not conclusive due to our small sample size.

The incidence and the risk factors of venous thromboembolism in Korean patients with pelvic or acetabular fractures

BackgroundPelvic ring and acetabular fractures are the results of high energy trauma, but there is a paucity of information available regarding the incidence and risk factors of venous thromboembolism (VTE) after these injuries in Asians. This study was undertaken to evaluate the incidence of VTE after a pelvic or an acetabular fracture and to identify predictive factors. MethodsA prospective evaluation was performed by indirect computed tomography (CT) venography in patients with pelvic or acetabular fractures. Ninety-five patients were examined by indirect CT venography. Fifty-five patients suffered from a pelvic ring injury (anteroposterior compression 5, lateral compression 25, vertical shear 25), and the remaining 40 from acetabular fractures (simple 18, complex 22). Indirect CT venography was performed within 1-2 weeks of initial trauma. Relationships between VTE and sex, age, fracture pattern, body mass index, injury severity score, period of immobilization, and need for surgical treatment were analyzed. Deep vein thrombosis (DVT) in a more proximal to popliteal vein and the existence of PE were considered clinically significant. ResultsThirty-two patients (33.7 %) were found to have VTE at an average of 11 days after initial injury. Clinically significant DVT was found 20 cases (21.1 %). No statistical difference was found between pelvic ring injuries and acetabular fractures with respect to the development of VTE. For those with pelvic ring injury, the incidence of VTE in those with a vertical shear injury (52 %) was significantly greater than in others with a pelvic ring injury (p = 0.014). Patients with an age >50 were found to be at greater risk of VTE (p = 0.032). ConclusionOur findings demonstrate that Korean patients with pelvic or acetabular fractures have a higher risk of VTE than is generally believed, and caution should be taken to prevent and treat VTE, especially in high energy pelvic ring injury and elderly patients.

The incidence, risk factors, and prognosis of recurrent venous thromboembolism (VTE) in patients with advanced solid cancers receiving anticoagulation therapy after the diagnosis of index VTE

Patients with cancer have been associated with increased risk of recurrent venous thromboembolism (VTE). However, data on recurrent VTE in Asian patients with advanced solid cancers are limited. MethodsThis study was conducted using data from the Korean VTE registry, which is an ongoing, prospective database. Patients were eligible if they had diagnosed with recurrent/metastatic solid cancers and initiated anticoagulation therapy following index VTE diagnosis. A total of 449 patients were included in this analysis. The 6-month and 12-month cumulative incidences of recurrent VTE were 20.6% and 27.0%, respectively. Isolated pulmonary embolism (PE) (51%) was the most predominant recurrence type. Pancreas as the primary tumor site, poor Eastern Cooperative Oncology Group performance status at the time of index VTE diagnosis, and initial presentation with PE were independent risk factors for developing recurrent VTE. With a median follow-up of 29.1months (range, 1.0-91.2), the median overall survival (OS) was 11.9months. Patients with recurrent VTE had a significantly worse OS than those without recurrent VTE (median, 8.4 vs. 13.0months, respectively; P=0.001). In conclusion, the incidence of recurrent VTE in Korean patients with advanced solid cancers is comparable with Caucasian patients. Pancreas as the primary tumor site, poor performance status, and initial presentation with PE are independent recurrent VTE risk factors in advanced cancer VTE patients. Additionally, OS is adversely affected by recurrent VTE.

The Prophylaxis of Venous Thromboembolism in Korean Patients with Total Knee Replacement Arthroplasty

The Prophylaxis of Venous Thromboembolism in Korean Patients with Total Knee Replacement Arthroplasty

Venous Thromboembolism in Korean Patients Undergoing Major Orthopedic Surgery: A Prospective Observational Study using Computed Tomographic (CT) Pulmonary Angiography and Indirect CT Venography

In patients undergoing major orthopedic surgery, data of deep venous thrombosis (DVT) and pulmonary embolism (PE) are lacking as studied by computed tomographic (CT) pulmonary angiography and indirect CT venography (CTPA-CTV). A prospective observational study was performed for 363 Korean patients undergoing major orthopedic surgery to determine the incidence of venous thromboembolism (VTE), especially proximal DVT and PE. The incidence of VTE was 16.3% (n=59). Of them, 8 patients (2.2%) were symptomatic. The rate of VTE was the highest in patients who underwent total knee replacement (40.4%), followed by hip fracture surgery (16.4%), and total hip replacement (8.7%; P<0.001). The incidence of PE was 6.6% (n=24). Of them, 4 patients (1.1%) were symptomatic. Forty-one patients (11.3%) were in the proximal DVT or PE group. Based on multivariate analysis, total knee replacement and age ≥65 yr were significant risk factors for proximal DVT or PE in patients undergoing major orthopedic surgery (odds ratio [OR], 2.4; 95% confidence interval [CI], 1.1-5.1; P=0.025; and OR, 2.1; 95% CI, 1.0-4.4; P=0.046, respectively). Taken together, the overall incidence of PE was 6.6% and rate of symptomatic PE rate was 1.1%. Knee joint replacement and age ≥65 yr were significant risk factors for proximal DVT or PE.

Metabolic Syndrome Is Associated With Venous Thromboembolism in the Korean Population

The metabolic syndrome (MS) is a known risk factor for arterial thromboembolism. Preliminary reports have also suggested the association between MS and venous thromboembolism (VTE). In this case-control study, we investigated the association between MS and VTE in Korean patients. Patients with objectively diagnosed VTE and healthy control subjects underwent clinical assessment for the presence of MS according to the National Cholesterol Education Adult Treatment Panel III criteria modified with body mass index (WHO Asian Pacific Perspective, 2000). The presence of known risk factors for VTE was ascertained. Patients with VTE secondary to cancer were excluded. The prevalence of MS was compared between VTE group and controls. Two hundred eight VTE patients and 300 controls were assessed. VTE was idiopathic in 91 patients and secondary to a known risk factor in 117. The prevalence of MS was significantly higher in VTE patients (47.6%) than in controls (37.7%) (OR: 1.50; 95% CI: 1.05 to 2.15, P=0.026). After adjusting for age, sex, and smoking status, metabolic MS remained independently associated with VTE (OR: 1.56; 95% CI: 1.07 to 2.27, P=0.020). In the subgroup analysis, MS was also independently associated with idiopathic VTE (OR: 1.71; 95% CI: 1.04 to 2.81, P=0.033), but not with secondary VTE (OR: 1.43; 95% CI: 0.91 to 2.99, P=0.121). Multivariate analysis demonstrated that high BMI (OR: 1.70, 95% CI: 1.01 to 2.87), decreased HDL cholesterol (OR: 1.99, 95% CI: 1.17 to 3.39), and elevated fasting glucose levels (OR: 2.31; 95% CI: 1.35 to 3.94) were associated with idiopathic VTE. MS is associated with VTE and in particular with idiopathic VTE in the Korean population.