Health care expenditures associated with venous thromboembolism among children

Introduction

We used health insurance claims data from large samples of Medicaid-enrolled and privately insured children to identify children with venous thromboembolism (VTE) and to assess their use of health services and associated expenditures during 2009.

Materials and Methods

Data from the 2009 Thomson Reuters MarketScan® Commercial Database and Multi-State Medicaid database were used to estimate annual expenditures for children 1-17 years of age with VTE. Generalized linear models were used to calculate adjusted annual expenditures for Medicaid-enrolled and privately insured children with VTE, controlling for age, sex, type of health plan, VTE classification (deep vein thrombosis and/or pulmonary embolism), and type of VTE event (idiopathic or secondary) and race (Medicaid only) or region (Commercial only).

Results

During 2009, Medicaid-enrolled and privately insured children with VTE had an average of 1-2 inpatient admissions and 8-10 non-emergency department visits. Unadjusted mean total expenditures were similar for Medicaid-enrolled and privately insured children with VTE, $105,359 and $87,767, respectively. Adjusted mean expenditures for children with secondary VTE were five times higher than for children with idiopathic VTE.

Conclusions

Given the high frequency of secondary VTE in children, most of the associated expenditures may be due to other health conditions. However, children who develop a VTE incur substantial costs of care, even in the absence of related conditions. Additional research is needed to evaluate the long term outcomes for children with VTE including rates of readmission, complications, and the impact of co-morbid conditions.     

Incidental venous thromboembolism detected by PET-CT in patients with cancer: Prevalence and impact on survival rate

Introduction

People with cancer are at increased risk of incidental venous thromboembolism (VTE) and PET-CT imaging is commonly used in this population. However, the prevalence of incidental VTE detected by PET-CT in patients with cancer and its impact on survival are unknown.

Materials and Methods

This retrospective study was approved by the local Institutional Review Board. 1331 consecutive adult patients with cancer who underwent PET-CT examination between 2009 and 2012 were included in the study (mean age: 57 ± 15 years). PET-CT reports were reviewed to identify patients with incidental VTE at the time of examination. Survival rates were assessed with Kaplan-Meier curves. The Cox proportional hazards model was used to determine the association between incidental VTE and overall survival, after controlling for clinical variables.

Results

Incidental VTE was detected in 19 patients (1.4%). Patients with genitourinary malignancies, colorectal cancer and lung cancer had the highest rates of incidental VTE at PET-CT. At multivariate analysis, incidental VTE detected by PET-CT was associated with worse overall survival independently of patient age, hospitalization status at time of PET-CT examination, and the presence of metastatic disease (Hazard ratio = 2.03; 95% confidence interval = 1.08-3.81, p = 0.028).

Conclusion

Incidental VTE was detected in 1.4% of adult patients with cancer undergoing PET-CT imaging. Diagnosis of incidental VTE at PET-CT imaging was associated with worse overall survival in this population.     

Old and new oral anticoagulants for venous thromboembolism and atrial fibrillation: a review of the literature

Heparin, fondaparinux and vitamin K antagonists (VKAs) are effective for the prevention and treatment of venous thromboembolism. VKAs reduce by almost 60% the rate of cardioembolic complications in patients with atrial fibrillation. The risk for bleeding and the inconvenience for laboratory monitoring, dose adjustment and drug or food interactions are the main limits for VKAs while parenteral administration is the main limit for heparin and fondaparinux. New oral anticoagulants with more predictable anticoagulant response and no need for laboratory monitoring have been shown to be effective for the prevention and treatment of venous thromboembolism and for the prevention of stroke and systemic embolism in patients with atrial fibrillation. The pharmacokinetic and pharmacodynamic profile of the new agents differ for mechanisms of action - mainly anti Xa and one antithrombin agent- bioavailability, half life, renal or live clearance. Drug interactions have been described with the new agents and inhibitors or inducers of P-gp or CYP3A4. Overall, in the prevention of venous thromboembolism after major elective orthopaedic surgery dabigatran was shown to be non-inferior, rivaroxaban and apixaban to be superior to enoxaparin. Both, rivaroxaban and dabigatran were shown to be non-inferior to low-molecular weight heparin and VKAs for the treatment of venous thromboembolism. Dabigatran 150 mg twice daily reduced the incidence of both ischemic and hemorrhagic stroke in patients with atrial fibrillation respect to warfarin. In these patients rivaroxaban and apixaban reduced the incidence of hemorrhagic stroke with a similar incidence of ischemic stroke. No bleeding concern emerged with the new anticoagulant agents in this indication.     

Thromboprophylaxis patterns,risk factors,and outcomes of care in the medically ill patient population

Introduction

Medically ill, hospitalized patients are at increased risk for venous thromboembolism (VTE) after discharge. This study aimed to examine thromboprophylaxis patterns, risk factors, and post-discharge outcomes.

Methods

This was a retrospective claims analysis involving administrative claims data and in-patient data abstracted from a sample of hospital charts. Patients aged ≥ 40 years hospitalized for ≥ 2 days for nonsurgical reasons between 2005 and 2009 were included. Hospital chart data were abstracted for a random sample of patients without evidence of anticoagulant use at 30 days post-discharge. The combined data determined whether in-patient thromboprophylaxis (anticoagulant or mechanical prophylaxis) reduces risk of VTE at 90 days post-discharge. Hazard ratios (HR) and odds ratios (OR) were calculated using Cox proportional hazard models and logistic regression.

Results

Of 141,628 patients in the claims analysis, 3.9% received anticoagulants (3.6% warfarin). VTE, rehospitalization, and mortality rates were 1.9%, 17.2%, and 6.2%, respectively. The strongest predictors of post-discharge VTE were history of VTE (HR = 4.0, 95% confidence interval [CI]: 3.3-4.8), and rehospitalization (HR = 3.9, 95% CI: 3.6-4.3). Of 504 medical charts, 209 (41.5%) reported in-patient thromboprophylaxis. There was no statistically significant difference in post-discharge VTE rates between patients who did and did not receive in-patient thromboprophylaxis. All-cause mortality was greater among patients without use of VTE prophylaxis.

Conclusion

Utilization rates of in-hospital and post-discharge VTE prophylaxis were low. In-hospital VTE prophylaxis did not reduce the risk of post-discharge VTE in the absence of post-discharge anticoagulation. Combined in-patient and post-discharge thromboprophylaxis lowered the odds of short-term, all-cause post-discharge mortality.     

Association of blood transfusion and venous thromboembolism after colorectal cancer resection

Introduction

Red blood cell (RBC) transfusion is a common event in the perioperative course of patients undergoing surgery. Transfused blood can disrupt the balance of coagulation factors and modulates the inflammatory cascade. Since inflammation and coagulation are tightly coupled, we postulated that RBC transfusion may be associated with the development of venous thromboembolic phenomena. We queried the American College of Surgeons’ National Surgical Quality Improvement Program (ACS NSQIP) database to examine the relationship between intraoperative blood transfusion and development of venous thromboembolism (VTE) in patients undergoing colorectal resection for cancer.

Materials and Methods

We analyzed the data from 2005 to 2009 for patients undergoing colorectal resections for cancer based on the primary procedure CPT-4 code and operative ICD-9 diagnosis code. The primary outcome was 30-day deep vein thrombosis (DVT) and/or pulmonary embolism (PE). Intraoperative transfusion of RBC's was categorized as: none, 1-2 units, 3-5 units and 6 units or more. DVT/PE occurrences were analyzed by multivariable forward stepwise regression (p for entry < .05, for exit > .10) to identify independent predictors of DVT.

Results

The database contained 21943 colorectal cancer resections. The DVT rate was 1.4% (306/21943) and the PE rate was 0.8% (180/21943). Patients were diagnosed with both only 40 times and the combined DVT or PE rate (VTE) was 2.0% (446/21943). After adjusting for age, gender, race, ASA (American Society of Anesthesiologists) class, emergency procedure, operative duration and complexity of the procedure (based on Relative Value Units, RVU's), along with six clinical risk factors, intraoperative blood transfusion was a significant risk factor for the development of VTE and the risk increased with increasing number of units transfused. Preoperative hematocrit did not enter the multivariable model as an independent predictor of VTE, nor did open versus laparoscopic resection or wound class.

Conclusion

In this study of 21943 patients undergoing colorectal resection for cancer, blood transfusion is associated with increased risk of VTE. Malignancy and surgery are known prothrombotic stimuli, the subset of patients receiving intraoperative RBC transfusion are even more at risk for VTE, emphasizing the need for sensible use of transfusions and rigorous thromboprophylaxis regimens.     

The MASTER registry on venous thromboembolism: description of the study cohort

INTRODUCTION: Information on the epidemiology and long-term clinical outcome of venous thromboembolism (VTE) is mainly based on data from clinical trials and thus may be not representative of the full spectrum of VTE patients. The aim of this multicenter registry (MASTER) was to prospectively collect data on the epidemiology and long-term clinical outcome of VTE in an unselected cohort of patients. MATERIALS AND METHODS: In symptomatic patients with objectively confirmed acute VTE, information about clinical presentation, diagnostic methods, temporary and permanent risk factors, pre-event prophylaxis and treatment were captured by an electronic data network at the time of the index event. A 24-month follow-up is currently ongoing. RESULTS: From January 2002 to October 2004, 2119 patients were included in the MASTER registry in 25 Italian centers. At entry, the mean patient age was 59.3+/-18.1 years (range 18-99 years). 1541 patients (72.7%) were affected by deep vein thrombosis, 206 patients (9.7%) by pulmonary embolism and 372 patients (17.5%) by both deep vein thrombosis and pulmonary embolism. 676 patients (31.9%) received home-treatment. 899 patients (42.4%) had one or more temporary risk factors. 381 patients (18.0%) had a known cancer at the time of the index event and in 50 patients (2.4%) a new cancer was discovered at the time of the index event. 311 patients (14.7%) had a previous VTE. CONCLUSIONS: Following a real world approach, our registry describes the clinical presentation, risk factors, diagnosis and treatment procedures in a large cohort of unselected patients with VTE.     

Predictors of attempted inferior vena cava filters retrieval in a tertiary care centre

Background

Retrieval rates of optional recovery inferior vena cava (IVC) filters in US hospitals range from 11 - 70%. We conducted a retrospective study in a Canadian tertiary care centre to determine retrieval rates and predictors of filter removal.

Methods

Consecutive patients who had a retrievable IVC filter inserted or removed between January 2007 and December 2010 were identified. Data collected included baseline demographics, indications for filter insertion and removal, documentation of an IVC filter management plan, reasons for non-retrieval, complications, and death.

Results

275 patients with a median age of 60 years were followed in hospital for a median of 17 patient-days (range 1–876). Indications for filter placement were acute or prior VTE with contraindication to anticoagulation (72.4%), high risk of PE (11.3%) and primary prophylaxis (13.8%). Retrieval was attempted in 165 patients (60%) and was successful in 146 patients (53.1%). The most common reason for failed retrieval was filter thrombus. Predictors of attempted retrieval included documentation of filter plan (odds ratio [OR] 16.7; p < 0.001), surgical indication for IVC filter insertion (OR 4.8; p = 0.002), age ≤ 70 years (OR 3.8; p = 0.001), Hematology service involvement (OR 3.0; p = 0.006), and presence of metastatic cancer (OR 0.2; p = 0.001). Thrombotic complications occurred in 48 patients, including 3 patients who died of fatal PE.

Conclusion

Our filter retrieval rate is suboptimal. Improvements in follow-up documentation or a dedicated clinical service may help increase retrieval rates.     

Evaluation of the predictive value of ICD-9-CM coded administrative data for venous thromboembolism in the United States

Objective

To determine the positive predictive value of International Classification of Disease, 9th Revision, Clinical Modification (ICD-9-CM) discharge codes for acute deep vein thrombosis or pulmonary embolism.

Materials and Methods

Retrospective review of 3456 cases hospitalized between 2005 and 2007 that had a discharge code for venous thromboembolism, using 3 sample populations: a single academic hospital, 33 University HealthSystem Consortium hospitals, and 35 community hospitals in a national Joint Commission study. Analysis was stratified by position of the code in the principal versus a secondary position.

Results

Among 1096 cases that had a thromboembolism code in the principal position the positive predictive value for any acute venous thrombosis was 95% (95%CI:93-97), whereas among 2360 cases that had a thromboembolism code in a secondary position the predictive value was lower, 75% (95%CI:71-80). The corresponding positive predictive values for lower extremity deep-vein thrombosis or pulmonary embolism were 91% (95%CI:86-95) and 50% (95%CI:41-58), respectively. More highly defined codes had higher predictive value. Among codes in a secondary position that were false positive, 22% (95%CI:16-27) had chronic/prior venous thrombosis, 15% (95%CI:10-19) had an upper extremity thrombosis, 6% (95%CI:4-8) had a superficial vein thrombosis, and 7% (95%CI:4-13) had no mention of any thrombosis.

Conclusions

ICD-9-CM codes for venous thromboembolism had high predictive value when present in the principal position, and lower predictive value when in a secondary position. New thromboembolism codes that were added in 2009 that specify chronic thrombosis, upper extremity thrombosis and superficial venous thrombosis should reduce the frequency of false-positive thromboembolism codes.     

Seasonal variation in the occurrence of venous thromboembolism: A report from the Korean Venous Thromboembolism Working Party

There have been conflicting results on seasonal variation in the occurrence of venous thromboembolism (VTE). It also has never been studied in Asian population. To address these issues, we investigated seasonal changes of the incidence of VTE in Korean population using 1,495 patients with VTE between January 2001 and December 2010. VTE occurred most frequently in the winter and least frequently in the summer (χ2 = 11.83, P = 0.008). In the subset analyses, the same trend was shown in the PE ± DVT group, the unprovoked VTE group, and the VTE without malignancy group. The monthly occurrence rate peaked in December and was at its lowest in July (P = 0.004). In conclusion, our study provides evidence that there is an increased risk for VTE in Korean population in the winter season.     

Risk factors for recurrent venous thromboembolism in young and middle-aged women

Background

It is a matter of debate whether women with an episode of VTE associated with estrogen have a lower risk of recurrence than women with an unprovoked VTE.

Objectives

To identify risk factors for recurrent VTE in women and to assess the risk of recurrent VTE associated with combined oral contraceptives (CHC) or menopausal hormone treatment (HT), compared to surgery-related and unprovoked VTE.

Patients/Methods

A cohort of 974 women aged 18–64 years with a first episode of VTE were followed-up for a median time of 5.2 years. All women were previously included as cases in the Swedish nation-wide case–control study “Thrombo Embolism Hormone Study” (TEHS). Hazard ratios for recurrence were calculated using univariable and multivariable Cox proportional hazards model.

Results

A total of 102 patients (10%) suffered from recurrent VTE. The annual rate of recurrence was 1.0% in patients with surgery/cast, 2.0% in patients with CHC/HT and 3.2% in patients with unprovoked first VTE. Adjusted hazards ratio (HR_a) for recurrence was 0.35 (95% CI 0.20-0.61) in women with VT provoked by surgery/cast while women with estrogen-associated VTE had a HR_a of 0.70 (95% CI 0.43-1.20) compared to women with unprovoked VTE.

Conclusion

Women 18–64 years are at low risk of recurrent VTE. Women with hormone associated VTE had a lower risk of recurrence than women with unprovoked VTE, but not as low as surgery/cast provoked VTE.     

Fish intake and venous thromboembolism: A Danish follow-up study

Introduction

Data on the association between fish intake and venous thromboembolism (VTE) is sparse and inconsistent.

Objective

To investigate whether intake of total, lean or fatty fish is associated with development of incident VTE.

Material and methods

This study is based on the Danish follow-up study Diet, Cancer and Health including 27,178 men and 29,876 women aged 50–64 with no history of cancer. Participants were included between 1993 and 1997 and followed through 2006. Information on fish intake and potential confounders was obtained from baseline questionnaires. The outcome was incident VTE (all) and idiopathic VTE. We used Cox proportional hazard models with age as time axis. Separate analyses were performed for men and women. Adjustment was made for BMI, smoking, physical activity, energy intake and women’s use of hormone replacement therapy.

Results

During follow-up, 641 incident VTE events were verified. We found no association between total fish intake and VTE, but moderate intake of fatty fish was associated with a statistically non-significant 20-40% lower risk of idiopathic VTE compared with consumption of a low intake (less than 8 g) of fatty fish per day.

Conclusions

Intake of neither total nor fatty fish was statistically significantly associated with the incidence rate of VTE. However, intake of fatty fish may be associated with a reduction of the risk of idiopathic VTE.     

Clinical probability assessment and D-dimer determination in patients with suspected deep vein thrombosis, a prospective multicenter management study

Objectives

To investigate the reliability of a combined strategy of clinical assessment score followed by a local D-dimer test to exclude deep vein thrombosis. For comparison D-dimer was analysed post hoc and batchwise at a coagulation laboratory.

Design

Prospective multicenter management study.

Setting

Seven hospitals in southern Sweden.

Subjects

357 patients with a suspected first episode of deep vein thrombosis (DVT) were prospectively recruited and pre-test probability score (Wells score) was estimated by the emergency physician. If categorized as low pre-test probability, D-dimer was analysed and if negative, DVT was considered to be ruled out. The primary outcome was recurrent venous thromboembolism (VTE) during 3 months of follow up.

Results

Prevalence of DVT was 23.5% (84/357). A low pre-test probability and a negative D-dimer result at inclusion was found in 31% (110/357) of the patients of whom one (0.9%, [95% CI 0.02-4.96]) had a VTE at follow up. Sensitivity, specificity, negative predictive value and negative likelihood ratio for our local D-dimer test in the low probability group were 85.7%, 74.5%, 98.2%, and 0,19 respectively compared to 85.6%, 67,6%, 97.9% and 0,23 using batchwise analysis at a coagulation laboratory.

Conclusion

Pre-test probability score and D-dimer safely rule out DVT in about 30% of outpatients with a suspected first episode of DVT. One out of 110 patients was diagnosed with DVT during follow up. No significant difference in diagnostic performance was seen between local D-dimer test and the post hoc batch analysis with the same reagent in the low probability group.     

FGB mutations leading to congenital quantitative fibrinogen deficiencies: An update and report of four novel mutations

Introduction

Causative mutations leading to congenital quantitative fibrinogen are frequently clustered in FGA encoding the fibrinogen Aα-chain. Mutations of FGB encoding the Bβ-chain are less common and of interest since the Bβ-chain is considered the rate-limiting factor in the hepatic production of the fibrinogen hexamer.

Method

Four novel FGB mutations were identified in two afibrinogenemic (one new-born and one 30 years old male) and hypofibrinogenemic (a 49 years old female) patient, with heterogeneous thrombotic and bleeding phenotype. The human fibrinogen beta chain precursor protein sequence (P02675) was obtained from the UniProt database. The resulting models were analysed in SwissPdbViewer 4.1 and POV-Ray 3.7.

Results

The FGB c.895 T>C p.Y299H (numbering from the initiator Met) and the FGB c.1415G>T p.G472V were predicted to be deleterious by SIFT analysis. The first replaces an uncharged aromatic amino acid side chain by a positively charged side chain modifying the balance in the distribution of hydrophobic and hydrophilic of the 10 Å neighbourhood residues. The second replaces one non-charged aliphatic side chain by another without any changes for the 10 Å surrounding region. The FGB c.352C>T p.Q118X leads to a severe premature termination codon and the FGB intron 4: IVS4-1G>C (c719-1G>C) leads to skipping of exon 5 or usage of a cryptic acceptor site located upstream or downstream of the normal site.

Conclusions

The continuous characterization of novel molecular defects responsible for fibrinogen deficiency combined with modelling of mutant proteins will continue to provide a better comprehension of the complexity of fibrinogen synthesis and physiology.     

Risk factors for venous thromboembolism in pre-and postmenopausal women

Introduction

Hemostasis in women is affected by changes of estrogen levels. The role of endogenous estrogens on risk of venous thromboembolism (VTE) remains unclear. The aim of this study was to investigate the importance of acquired and genetic risk factors for VTE in pre-and postmenopausal women.

Method

In a nationwide case-control study we included as cases 1470 women, 18 to 64 years of age with a first time VTE. The 1590 controls were randomly selected and matched by age to the cases. Information on risk factors was obtained by interviews and DNA-analyses. We used unconditional logistic regression to calculate odds ratios (ORs) with 95% confidence intervals (CIs).

Results

The ORs were generally of similar magnitude in pre- and postmenopausal women. The highest risk was for the combination of surgery and cast (adjusted OR 54.12, 95% CI 16.62-176.19) in postmenopausal women. The adjusted OR for use of menopausal hormone therapy was 3.73 (95% CI 1.86-7.50) in premenopausal and 2.22 (95% CI 1.54-3.19) in postmenopausal women. Overweight was linked to an increased risk and exercise to a decreased risk, regardless of menopausal status.

Conclusion

Menopausal status had only minor influence on the risk levels. Acquired transient risk factors conveyed the highest risks for VTE.     

Incidental venous thromboembolism in cancer patients: prevalence and consequence

Introduction

Careful re-evaluation of CT-scans for cancer staging frequently reveals unsuspected venous thromboembolism (VTE) on CT-scans. However, it is unknown how often these findings lead to anticoagulant treatment in daily clinical practice.

Methods

Reports from thoracic and/or abdominal CT-scans performed in a consecutive series of patients to stage cancer were retrospectively evaluated to determine the prevalence of incidental venous thromboembolism (iVTE). Presence of pre-existing signs of VTE, anticoagulant treatment and 3-month follow-up were analysed in patients with iVTE.

Results

A total of 1466 staging scans (838 patients) from the year 2006 were included in the analysis. The prevalence of VTE in patients was 2.5% (21/838 patients, 95% confidence interval 1.6-3.8%); the prevalence of VTE on scans was 1.4% (21/1466 scans, 95% CI 0.9-2.2%). Incidental PE or deep vein thrombosis (DVT) was observed in 11 (1.3%, 0.7-2.3%) and abdominal vein thrombosis in 9 patients (1.1%, 0.6-2.0%; in the portal (5), mesenteric (3) and renal vein (1), respectively). Nine out of eleven patients with PE/DVT were treated with anticoagulants, while none of the patients with thrombosis in other locations received anticoagulants. One of these patients developed symptomatic PE one month later; otherwise, follow up was uneventful in the untreated patients.

Conclusion

The prevalence of iVTE in patients with cancer in clinical practice is relatively low and most patients with PE or DVT are treated with anticoagulants. For patients with thrombi in other locations, further research is necessary to understand the natural history of these thrombi in order to develop adequate guidelines.     

Sensitive and quantitative, 10-min immunofluorometric assay for D-Dimer in whole blood

INTRODUCTION: Normal concentrations of D-Dimer can be used to exclude venous thromboembolism (VTE). However, methods for sensitive and quantitative D-Dimer measurements at the point-of-care (POC) are still limited. MATERIALS AND METHODS: We developed a 10-min, non-competitive immunofluorometric assay for D-Dimer in citrated whole blood and plasma using pre-dispensed reagents dried in single assay wells. The simple, automated assay procedure comprises a 1:50 sample dilution, one-step incubation, washing, and time-resolved fluorometric measurement directly from the wet well surface. RESULTS: The limits of detection (background + 3SD) and quantification (CV <15%) were 0.05 and 0.2 mg/L D-Dimer, respectively, and the assay was linear up to 400 mg/L. Correlations to Roche TinaQuant (r=0.726, n=200) and Biopool Auto.Dimer (r=0.190, n=149) were carried out using citrated plasma. Diagnostic sensitivity, specificity, and negative (NPV) and positive (PPV) predictive values were 98.7%, 64.4%, 99.1% and 55.1%, and 92.2%, 81.0%, 95.9% and 68.3%, respectively, using cut-off values of 0.6 and 1.0 mg/L, respectively, in outpatients with deep vein thrombosis (DVT) and/or pulmonary embolism (PE) (n=77) compared with outpatients with various other diseases (n=174). The within- and between-run CVs near the cut-off values were < or =10% in both whole blood and plasma. The 95th percentile upper range in apparently healthy individuals was 0.68 mg/L of whole blood (n=101). CONCLUSIONS: The high sensitivity and NPV suggest that the rapid immunofluorometric assay could be valuable for rapid exclusion of VTE in outpatients. With appropriate cut-offs, the assay could potentially be used as a stand-alone test or combined with clinical probability assessment, but further studies are required.     

Comparison of the diagnostic performance of the original and modified Wells score in inpatients and outpatients with suspected deep vein thrombosis

Introduction

The original and modified Wells score are widely used prediction rules for pre-test probability assessment of deep vein thrombosis (DVT). The objective of this study was to compare the predictive performance of both Wells scores in unselected patients with clinical suspicion of DVT.

Methods

Consecutive inpatients and outpatients with a clinical suspicion of DVT were prospectively enrolled. Pre-test DVT probability (low/intermediate/high) was determined using both scores. Patients with a non-high probability based on the original Wells score underwent D-dimers measurement. Patients with D-dimers < 500 μg/L did not undergo further testing, and treatment was withheld. All others underwent complete lower limb compression ultrasound, and those diagnosed with DVT were anticoagulated. The primary study outcome was objectively confirmed symptomatic venous thromboembolism within 3 months of enrollment.

Results

298 patients with suspected DVT were included. Of these, 82 (27.5%) had DVT, and 46 of them were proximal. Compared to the modified score, the original Wells score classified a higher proportion of patients as low-risk (53 vs 48%; p < 0.01) and a lower proportion as high-risk (17 vs 15%; p = 0.02); the prevalence of proximal DVT in each category was similar with both scores (7-8% low, 16-19% intermediate, 36-37% high). The area under the receiver operating characteristic curve regarding proximal DVT detection was similar for both scores, but they both performed poorly in predicting isolated distal DVT and DVT in inpatients.

Conclusion

The study demonstrates that both Wells scores perform equally well in proximal DVT pre-test probability prediction. Neither score appears to be particularly useful in hospitalized patients and those with isolated distal DVT.     

Contribution of multiple thrombophilic and transient risk factors in the development of cerebral venous thrombosis

INTRODUCTION: Cerebral venous thrombosis (CVT), deep vein thrombosis (DVT) and/or pulmonary embolism (PE) have been associated with thrombophilic defects. However, in contrast to DVT or PE, CVT is a rare disease. We performed a study to identify differences in thrombotic risk profile, predisposing to CVT rather than DVT or PE, particularly the contribution of oral contraception and 11 thrombophilic defects. MATERIALS AND METHODS: A single center case-control study (63 CVT cases and 209 controls with DVT or PE) was performed. RESULTS: Of CVT patients, 11% had experienced prior DVT or PE, and none had recurrent CVT at 5 years follow-up. CVT was more frequently observed in females (79% versus 51%, P<0.001). It was more often secondary (75% versus 50%, P<0.001), mainly due to the difference in age between both groups. At presentation of CVT and DVT/PE, oral contraceptives were used by 78% and 74% of non-pregnant fertile women (P=0.8), respectively. Any thrombophilic defect was demonstrated in 88% of CVT and 75% of DVT/PE patients (P=0.22), sex and age matched. Individual and two or more defects were equally distributed among both groups. CONCLUSIONS: We conclude that a majority of CVT and DVT or PE patients show single or multiple thrombophilic defects. At presentation, oral contraceptive intake was observed more frequently in CVT patients. However, no differences were observed in thrombotic risk profile between both groups of comparable age. Hence, additional unknown risk factors should be considered to explain the different sites of thrombosis in these patients.