Diagnostic management of acute pulmonary embolism: a prediction model based on a patient data meta-analysis.

AIMS: Risk stratification is used for decisions regarding need for imaging in patients with clinically suspected acute pulmonary embolism (PE). The aim was to develop a clinical prediction model that provides an individualized, accurate probability estimate for the presence of acute PE in patients with suspected disease based on readily available clinical items and D-dimer concentrations. METHODS AND RESULTS: An individual patient data meta-analysis was performed based on sixteen cross-sectional or prospective studies with data from 28 305 adult patients with clinically suspected PE from various clinical settings, including primary care, emergency care, hospitalized and nursing home patients. A multilevel logistic regression model was built and validated including ten a priori defined objective candidate predictors to predict objectively confirmed PE at baseline or venous thromboembolism (VTE) during follow-up of 30 to 90 days. Multiple imputation was used for missing data. Backward elimination was performed with a P-value <0.10. Discrimination (c-statistic with 95% confidence intervals [CI] and prediction intervals [PI]) and calibration (outcome:expected [O:E] ratio and calibration plot) were evaluated based on internal-external cross-validation. The accuracy of the model was subsequently compared with algorithms based on the Wells score and D-dimer testing. The final model included age (in years), sex, previous VTE, recent surgery or immobilization, haemoptysis, cancer, clinical signs of deep vein thrombosis, inpatient status, D-dimer (in µg/L), and an interaction term between age and D-dimer. The pooled c-statistic was 0.87 (95% CI, 0.85-0.89; 95% PI, 0.77-0.93) and overall calibration was very good (pooled O:E ratio, 0.99; 95% CI, 0.87-1.14; 95% PI, 0.55-1.79). The model slightly overestimated VTE probability in the lower range of estimated probabilities. Discrimination of the current model in the validation data sets was better than that of the Wells score combined with a D-dimer threshold based on age (c-statistic 0.73; 95% CI, 0.70-0.75) or structured clinical pretest probability (c-statistic 0.79; 95% CI, 0.76-0.81). CONCLUSION: The present model provides an absolute, individualized probability of PE presence in a broad population of patients with suspected PE, with very good discrimination and calibration. Its clinical utility needs to be evaluated in a prospective management or impact study. REGISTRATION: PROSPERO ID 89366.

Apixaban thromboprophylaxis in ambulatory patients with cancer and obesity: Insights from the AVERT trial.

BACKGROUND: The use of direct oral anticoagulants (DOACs) in obese patients is uncertain. It is unclear if body mass index (BMI) affects the safety and efficacy of DOACs for the primary prevention of venous thromboembolism (VTE) in high-risk ambulatory patients with cancer. We sought to determine the outcomes associated with the use of apixaban for the primary prevention of cancer-associated VTE according to BMI. METHODS: The randomized, double-blinded, placebo-controlled AVERT trial evaluated apixaban thromboprophylaxis in intermediate-to-high risk ambulatory cancer patients receiving chemotherapy. For this post-hoc analysis, the primary efficacy and safety outcomes were objectively confirmed VTE and clinically relevant bleeding (major and clinically relevant non-major bleeding), respectively. Obesity was defined as BMI ≥30 kg/m2. RESULTS: Among 574 patients randomized, 217 (37.8 %) patients had BMI ≥30 kg/m2. Obese patients were overall younger, more likely to be female, had higher creatinine clearance and hemoglobin, lower platelet count, and better ECOG performance status. Compared to placebo, apixaban thromboprophylaxis was associated with reduced VTE in both obese (hazard ratio [HR] 0.26; 95 % confidence interval [CI], 0.14-0.46; p < 0.0001) and non-obese (HR 0.54; 95%CI, 0.29-1.00; p = 0.049) patients. The HR for clinically relevant bleeding (apixaban vs. placebo) was numerically higher in obese (2.09; 95%CI, 0.96-4.51; p = 0.062) than non-obese subjects (1.23; 95%CI, 0.71-2.13; p = 0.46), but overall in line with the risks observed in the general trial population. CONCLUSIONS: In the AVERT trial enrolling ambulatory cancer patients receiving chemotherapy, we found no substantial differences in the efficacy or safety of apixaban thromboprophylaxis across obese and non-obese subjects.

Efficacy and safety of apixaban for primary prevention of thromboembolism in patients with cancer and a central venous catheter: A subgroup analysis of the AVERT Trial.

INTRODUCTION: Central venous catheters (CVC) are associated with an increased risk of venous thromboembolism (VTE) in patients with cancer. Primary thromboprophylaxis using a direct oral anticoagulant decreases the risk of VTE in intermediate-to-high risk ambulatory cancer patients. We assessed the efficacy and safety of thromboprophylaxis with apixaban in the subpopulation of patients with cancer and a CVC in the AVERT trial. METHODS: The AVERT study was a randomized, placebo-controlled, double-blind clinical trial assessing the efficacy and safety of apixaban for primary thromboprophylaxis in patients with cancer initiating chemotherapy who were at intermediate to high risk of VTE. The primary efficacy outcome was objectively confirmed VTE within 180 days of randomization and the primary safety outcome was major bleeding. The hazard ratios (HRs) were calculated using a Cox regression model controlling for age, gender, and center. RESULTS: A total of 217 patients had a CVC and were included in the subgroup analyses with 126 and 91 patients receiving apixaban or placebo, respectively. VTE occurred in 6 (4.8%) patients in the apixaban group and 17 (18.7%) patients in the placebo group (HR 0.26; 95% CI, 0.14-0.47; p < 0.0001). Major bleeding occurred in 2 (1.6%) patients in the apixaban group and 2 (2.2%) patients in the placebo group (HR 0.69; 95% CI, 0.20-2.35; p = 0.556). CONCLUSIONS: Primary thromboprophylaxis with apixaban in patients with cancer and a CVC was associated with a reduced risk of VTE in the AVERT study population, without an increased risk of bleeding. (Funded by the CIHR and Bristol-Myers Squibb-Pfizer Alliance; NCT02048865).

Safety and Efficiency of Diagnostic Strategies for Ruling Out Pulmonary Embolism in Clinically Relevant Patient Subgroups : A Systematic Review and Individual-Patient Data Meta-analysis.

BACKGROUND: How diagnostic strategies for suspected pulmonary embolism (PE) perform in relevant patient subgroups defined by sex, age, cancer, and previous venous thromboembolism (VTE) is unknown. PURPOSE: To evaluate the safety and efficiency of the Wells and revised Geneva scores combined with fixed and adapted D-dimer thresholds, as well as the YEARS algorithm, for ruling out acute PE in these subgroups. DATA SOURCES: MEDLINE from 1 January 1995 until 1 January 2021. STUDY SELECTION: 16 studies assessing at least 1 diagnostic strategy. DATA EXTRACTION: Individual-patient data from 20 553 patients. DATA SYNTHESIS: Safety was defined as the diagnostic failure rate (the predicted 3-month VTE incidence after exclusion of PE without imaging at baseline). Efficiency was defined as the proportion of individuals classified by the strategy as "PE considered excluded" without imaging tests. Across all strategies, efficiency was highest in patients younger than 40 years (47% to 68%) and lowest in patients aged 80 years or older (6.0% to 23%) or patients with cancer (9.6% to 26%). However, efficiency improved considerably in these subgroups when pretest probability-dependent D-dimer thresholds were applied. Predicted failure rates were highest for strategies with adapted D-dimer thresholds, with failure rates varying between 2% and 4% in the predefined patient subgroups. LIMITATIONS: Between-study differences in scoring predictor items and D-dimer assays, as well as the presence of differential verification bias, in particular for classifying fatal events and subsegmental PE cases, all of which may have led to an overestimation of the predicted failure rates of adapted D-dimer thresholds. CONCLUSION: Overall, all strategies showed acceptable safety, with pretest probability-dependent D-dimer thresholds having not only the highest efficiency but also the highest predicted failure rate. From an efficiency perspective, this individual-patient data meta-analysis supports application of adapted D-dimer thresholds. PRIMARY FUNDING SOURCE: Dutch Research Council. (PROSPERO: CRD42018089366).

Efficacy and safety of primary thromboprophylaxis for the prevention of venous thromboembolism in patients with cancer and a central venous catheter: A systematic review and meta-analysis.

BACKGROUND: Venous thromboembolism (VTE) is a leading cause of mortality in patients with cancer and is associated with significant morbidity and healthcare expenditure. The risk of VTE is increased following the insertion of a central venous catheter (CVC) for chemotherapy delivery and supportive care. The risks and benefits of primary thromboprophylaxis in patients with cancer and CVC are unclear. OBJECTIVE: We sought to assess the rates of VTE and bleeding complications and to determine the efficacy and safety of primary thromboprophylaxis in adult patients with cancer and a CVC. METHODS: A systematic search of MEDLINE, EMBASE, and all EBM was conducted. Randomized controlled trials (RCTs) of adult patients with cancer and a CVC receiving primary thromboprophylaxis compared to observation/placebo were included. The primary efficacy and safety outcomes were total VTE and major bleeding episodes, respectively. RESULTS: A total of 12 RCTs (3545 patients) were included in the analysis. The total rates of VTE were significantly lower in patients receiving thromboprophylaxis compared to those not receiving primary prevention (7.6% vs. 13%; Odds Ratio (OR) 0.51, 95% CI 0.32-0.82, p < 0.01). The rates of major bleeding complications were not higher in patients receiving thromboprophylaxis (0.9% vs. 0.6%; OR 1.12, 95% CI 0.29-4.40, p = 0.87). CONCLUSIONS: Primary thromboprophylaxis significantly reduced the risk of VTE without increasing the risk of major bleeding complications in patients with cancer and CVC. Future studies are needed to confirm these findings.

Diagnosing deep vein thrombosis in cancer patients with suspected symptoms: An individual participant data meta-analysis.

BACKGROUND: A previous individual participant data (IPD) meta-analysis showed that the Wells rule and D-dimer testing cannot exclude suspected deep vein thrombosis (DVT) in cancer patients. OBJECTIVES: To explore reasons for this reduced diagnostic accuracy and to optimize the diagnostic pathway for cancer patients suspected of DVT. PATIENTS AND METHODS: Using IPD from 13 studies in patients with suspected DVT, DVT prevalence and the predictive value of the Wells rule items and D-dimer testing were compared between patients with and without cancer. Next, we developed a prediction model with five variables selected from all available diagnostic predictors. RESULTS: Among the 10 002 suspected DVT patients, there were 834 patients with cancer. The median prevalence of DVT in these patients with cancer was 37.5% (interquartile range [IQR], 30.8-45.5), whereas it was 15.1% (IQR, 11.5-16.7) in patients without cancer. Diagnostic performance of individual Wells rule items and D-dimer testing was similar across patients with and without cancer, except "immobility" and "history of DVT." The newly developed rule showed a pooled c-statistic 0.80 (95% confidence interval [CI], 0.75-0.83) and good calibration. However, using this model, still only 4.3% (95% CI, 3.0-5.7) of the suspected patients with cancer could be identified with a predicted DVT posttest probability of <2%. CONCLUSIONS: Likely because of the high prevalence of DVT, clinical models followed by D-dimer testing fail to rule out DVT efficiently in cancer patients suspected of DVT. Direct referral for compression ultrasonography appears to be the preferred approach for diagnosis of suspected DVT in cancer patients.

Risk of Cardiovascular Events and Mortality Among Elderly Patients With Reduced GFR Receiving Direct Oral Anticoagulants.

RATIONALE & OBJECTIVE: Evidence for the efficacy of direct oral anticoagulants (DOACs) to prevent cardiovascular (CV) events and mortality in older individuals with a low estimated glomerular filtration rate (eGFR) is lacking. We sought to characterize the association of oral anticoagulant use with CV morbidity in elderly patients with or without reductions in eGFRs, comparing DOACs with vitamin K antagonists (VKAs). STUDY DESIGN: Population-based retrospective cohort study. SETTINGS & PARTICIPANTS: All individuals 66 years or older with an initial prescription for oral anticoagulants dispensed in Ontario, Canada, from 2009 to 2016. EXPOSURE: DOACs (apixaban, dabigatran, and rivaroxaban) compared with VKAs by eGFR group (≥60, 30-59, and<30mL/min/1.73m2). OUTCOMES: The primary outcome was a composite of a CV event (myocardial infarction, revascularization, or ischemic stroke) or mortality. Secondary outcomes were CV events alone, mortality, and hemorrhage requiring hospitalization. ANALYTICAL APPROACH: High-dimensional propensity score matching of DOAC to VKA users and Cox proportional hazards regression. RESULTS: 27,552 new DOAC users were matched to 27,552 new VKA users (median age, 78 years; 49% women). There was significantly lower risk for CV events or mortality among DOAC users compared with VKA users (event rates of 79.78 vs 99.77 per 1,000 person-years, respectively; HR, 0.82 [95% CI, 0.75-0.90]) and lower risk for hemorrhage (event rates of 10.35 vs 16.77 per 1,000 person-years, respectively; HR, 0.73 [95% CI, 0.58-0.91]). There was an interaction between eGFR and the association of anticoagulant class with the primary composite outcome (P<0.02): HRs of 1.01 [95% CI, 0.92-1.12], 0.83 [95% CI, 0.75-0.93], and 0.75 [95% CI, 0.51-1.10] for eGFRs of≥60, 30 to 59, and<30mL/min/1.73m2. No interaction was detected for the outcome of hemorrhage. LIMITATIONS: Retrospective observational study design limits causal inference; dosages of DOACs and international normalized ratio values were not available; low event rates in some subgroups limited statistical power. CONCLUSIONS: DOACs compared with VKAs were associated with lower risk for the composite of CV events or mortality, an association for which the strength was most apparent among those with reduced eGFRs. The therapeutic implications of these findings await further study.

The value of sPESI for risk stratification in patients with pulmonary embolism.

INTRODUCTION: Various risk stratification methods exist for patients with pulmonary embolism (PE). We used the simplified Pulmonary Embolism Severity Index (sPESI) as a risk-stratification method to understand the Veterans Health Administration (VHA) PE population. MATERIALS AND METHODS: Adult patients with ≥ 1 inpatient PE diagnosis (index date = discharge date) from October 2011-June 2015 as well as continuous enrollment for ≥ 12 months pre- and 3 months post-index date were included. We defined a sPESI score of 0 as low-risk (LRPE) and all others as high-risk (HRPE). Hospital-acquired complications (HACs) during the index hospitalization, 90-day follow-up PE-related outcomes, and health care utilization and costs were compared between HRPE and LRPE patients. RESULTS: Of 6746 PE patients, 95.4% were men, 67.7% were white, and 22.0% were African American; LRPE occurred in 28.4% and HRPE in 71.6%. Relative to HRPE patients, LRPE patients had lower Charlson Comorbidity Index scores (1.0 vs. 3.4, p < 0.0001) and other baseline comorbidities, fewer HACs (11.4% vs. 20.0%, p < 0.0001), less bacterial pneumonia (10.6% vs. 22.3%, p < 0.0001), and shorter average inpatient lengths of stay (8.8 vs. 11.2 days, p < 0.0001) during the index hospitalization. During follow-up, LRPE patients had fewer PE-related outcomes of recurrent venous thromboembolism (4.4% vs. 6.0%, p = 0.0077), major bleeding (1.2% vs. 1.9%, p = 0.0382), and death (3.7% vs. 16.2%, p < 0.0001). LRPE patients had fewer inpatient but higher outpatient visits per patient, and lower total health care costs ($12,021 vs. $16,911, p < 0.0001) than HRPE patients. CONCLUSIONS: Using the sPESI score identifies a PE cohort with a lower clinical and economic burden.

Predictors of Hospital Length of Stay among Patients with Low-risk Pulmonary Embolism.

BACKGROUND: Increased hospital length of stay is an important cost driver in hospitalized low-risk pulmonary embolism (LRPE) patients, who benefit from abbreviated hospital stays. We sought to measure length-of-stay-associated predictors among Veterans Health Administration LRPE patients. METHODS: Adult patients (aged ≥18 years) with ≥1 inpatient pulmonary embolism (PE) diagnosis (index date = discharge date) between 10/2011-06/2015 and continuous enrollment for ≥12 months pre- and 3 months post-index were included. PE patients with simplified Pulmonary Embolism Stratification Index score 0 were considered low risk; all others were considered high risk. LRPE patients were further stratified into short (≤2 days) and long length of stay cohorts. Logistic regression was used to identify predictors of length of stay among low-risk patients. RESULTS: Among 6746 patients, 1918 were low-risk (28.4%), of which 688 (35.9%) had short and 1230 (64.1%) had long length of stay. LRPE patients with computed tomography angiography (Odds ratio [OR]: 4.8, 95% Confidence interval [CI]: 3.82-5.97), lung ventilation/perfusion scan (OR: 3.8, 95% CI: 1.86-7.76), or venous Doppler ultrasound (OR: 1.4, 95% CI: 1.08-1.86) at baseline had an increased probability of short length of stay. Those with troponin I (OR: 0.7, 95% CI: 0.54-0.86) or natriuretic peptide testing (OR: 0.7, 95% CI: 0.57-0.90), or more comorbidities at baseline, were less likely to have short length of stay. CONCLUSION: Understanding the predictors of length of stay can help providers deliver efficient treatment and improve patient outcomes which potentially reduces the length of stay, thereby reducing the overall burden in LRPE patients.

Clinical and Economic Outcomes in Low-risk Pulmonary Embolism Patients Treated with Rivaroxaban versus Standard of Care.

BACKGROUND: Rivaroxaban, a fixed-dose oral direct factor Xa inhibitor, does not require continuous monitoring and thus reduces the hospital stay and economic burden in low-risk pulmonary embolism (LRPE) patients. Study Question: What is the effectiveness of rivaroxaban versus the standard of care (SOC; low-molecular-weight heparin, unfractionated heparin, warfarin) among LRPE patients in the Veterans Health Administration? STUDY DESIGN: Adult patients with continuous health plan enrollment for ≥12 months pre- and 3 months post-inpatient PE diagnosis (index date=discharge date) between October 1, 2011-June 30, 2015 and an anticoagulant claim during the index hospitalization were included. MEASURES AND OUTCOMES: Patients scoring 0 points on the simplified Pulmonary Embolism Stratification Index were considered low-risk and were stratified into SOC and rivaroxaban cohorts. Propensity score matching (PSM) was used to compare hospital-acquired complications (HACs), PE-related outcomes (recurrent venous thromboembolism, major bleeding, and death), and healthcare utilization and costs between the rivaroxaban and SOC cohorts. RESULTS: Among 6746 PE patients, 1918 were low-risk; of these, 73 were prescribed rivaroxaban, 1546 were prescribed SOC, and 299 were prescribed other anticoagulants during the index hospitalization. After 1:3 PSM, 64 rivaroxaban and 192 SOC patients were included. During the index hospitalization, rivaroxaban users (versus SOC) had similar inpatient length of stay (LOS; 7.0 vs 6.7 days, standardized difference [STD]=1.8) but fewer HACs (4.7% vs 10.4%; STD: 21.7). In the 90-day post-discharge period, PE-related outcome rates were similar between the cohorts (all p>0.05). However, rivaroxaban users had fewer outpatient (15.9 vs 20.4; p=0.0002) visits per patient as well as lower inpatient ($765 vs $2,655; p<0.0001), pharmacy ($711 vs $1,086; p=0.0033), and total costs ($6,270 vs $9,671; p=0.0027). CONCLUSIONS: LRPE patients prescribed rivaroxaban had similar index LOS and PE-related outcomes, but fewer HACs, and lower total costs than those prescribed SOC.

Homocysteine levels associate with subtle changes in leukocyte DNA methylation: an epigenome-wide analysis.

AIM: Homocysteine (Hcy) is a sensitive marker of one-carbon metabolism. Higher Hcy levels have been associated with global DNA hypomethylation. We investigated the association between plasma Hcy and epigenome-wide DNA methylation in leukocytes. METHODS: Methylation was measured using Illumina 450 k arrays in 2035 individuals from six cohorts. Hcy-associated differentially methylated positions and regions were identified using meta-analysis. RESULTS: Three differentially methylated positions cg21607669 (SLC27A1), cg26382848 (AJUBA) and cg10701000 (KCNMA1) at chromosome 19, 14 and 10, respectively, were significantly associated with Hcy. In addition, we identified 68 Hcy-associated differentially methylated regions, the most significant of which was a 1.8-kb spanning domain (TNXB/ATF6B) at chromosome 6. CONCLUSION: We identified novel epigenetic loci associated with Hcy levels, of which specific role needs to be further validated.

Benefit of early discharge among patients with low-risk pulmonary embolism.

Clinical guidelines recommend early discharge of patients with low-risk pulmonary embolism (LRPE). This study measured the overall impact of early discharge of LRPE patients on clinical outcomes and costs in the Veterans Health Administration population. Adult patients with ≥1 inpatient diagnosis for pulmonary embolism (PE) (index date) between 10/2011-06/2015, continuous enrollment for ≥12 months pre- and 3 months post-index date were included. PE risk stratification was performed using the simplified Pulmonary Embolism Stratification Index. Propensity score matching (PSM) was used to compare 90-day adverse PE events (APEs) [recurrent venous thromboembolism, major bleed and death], hospital-acquired complications (HACs), healthcare utilization, and costs among short (≤2 days) versus long length of stay (LOS). Net clinical benefit was defined as 1 minus the combined rate of APE and HAC. Among 6,746 PE patients, 95.4% were men, 22.0% were African American, and 1,918 had LRPE. Among LRPE patients, only 688 had a short LOS. After 1:1 PSM, there were no differences in APE, but short LOS had fewer HAC (1.5% vs 13.3%, 95% CI: 3.77-19.94) and bacterial pneumonias (5.9% vs 11.7%, 95% CI: 1.24-3.23), resulting in better net clinical benefit (86.9% vs 78.3%, 95% CI: 0.84-0.96). Among long LOS patients, HACs (52) exceeded APEs (14 recurrent DVT, 5 bleeds). Short LOS incurred lower inpatient ($2,164 vs $5,100, 95% CI: $646.8-$5225.0) and total costs ($9,056 vs $12,544, 95% CI: $636.6-$6337.7). LRPE patients with short LOS had better net clinical outcomes at lower costs than matched LRPE patients with long LOS.

Association between rivaroxaban use and length of hospital stay, treatment costs and early outcomes in patients with pulmonary embolism: a systematic review of real-world studies.

BACKGROUND: In the EINSTEIN-Pulmonary Embolism (PE) trial, subjects randomized to rivaroxaban versus enoxaparin bridging to vitamin K antagonist (VKA) therapy experienced a reduced index hospital length of stay (LOS). We sought to conduct a systematic review of real-world studies comparing LOS, costs and early outcomes among patients treated with rivaroxaban or parenterally bridged VKA in routine practice. METHODS: We searched Medline and Scopus from 1 January 2011 to 30 November 2016 to identify observational studies comparing acute PE patients anticoagulated with rivaroxaban or parenterally bridged VKA and reporting data on index hospital LOS, costs and/or early post-PE outcomes. Studies not using appropriate methods for minimizing confounding bias or not published in English were excluded. RESULTS: Five studies met inclusion criteria. Rivaroxaban use was associated with decreased index hospital LOS (range: 1.36-1.70 days) and treatment costs (range: $1818-$2688) during an index stay compared to parenterally bridged warfarin. No differences in early readmission for recurrent thrombosis were noted between anticoagulation strategies. Readmission for major bleeding was rare in both cohorts. Similar reductions in LOS (range: 0.23-4.3 days) and costs (range: $251-$7094) were observed with rivaroxaban in studies restricted to patients deemed low risk for early complications by clinical gestalt or by a clinical- or claims-based risk stratification tool. CONCLUSIONS: Regardless of patient predicted risk of post-PE complications, real-world studies suggest that rivaroxaban is associated with a reduced hospital LOS and costs versus parenterally bridged warfarin, without increasing readmission.

Overall Effectiveness of Rivaroxaban in Patients with Pulmonary Embolism.

PURPOSE: Due to limited evidence on the impact of rivaroxaban in clinical practice, we compared the effectiveness of rivaroxaban versus standard of care (SOC) among patients in the Veterans Health Administration. METHODS: Adult patients with continuous enrollment in a health plan with medical and pharmacy benefits for ≥12 months before and ≥3 months after an inpatient diagnosis of pulmonary embolism (PE) between October 1, 2011, and June 30, 2015, and a prescription claim for an anticoagulant during the index hospitalization, were included. SOC drugs were low-molecular-weight heparin, unfractionated heparin, and warfarin. Propensity score matching was used in comparing PE-related outcomes (recurrent venous thromboembolism, major bleeding, and death), hospital-acquired complications (HACs), health care resource utilization, and costs among patients receiving SOC versus rivaroxaban. We defined net clinical benefit as 1 minus the combined rate of PE-related outcomes and HACs. FINDINGS: Among 6746 patients with PE, 208 received rivaroxaban, 4641 received SOC and 1897 received other anticoagulants. Most (95%) were male; 22% were black. After 1:3 propensity score matching, there were 203 rivaroxaban and 609 SOC patients. During the 90-day follow-up, rivaroxaban users had similar rates of PE-related outcomes, but fewer had experienced at least 1 HAC (10.3% vs 15.9%; P = 0.0506), resulting in better net clinical benefit (82.8% vs 71.1%; P = 0.001). Rivaroxaban users had fewer outpatient visits per patient (17.0 vs 19.9; P = 0.0005), a similar rehospitalization rate (0.2 vs 0.3; P = 0.084), lesser inpatient costs (US $3501 vs $6189; P < 0.0001), lesser inpatient costs and lesser total costs ($10,545 vs $14,192; P = 0.0002). When the sample was limited to patients with low-risk PE, we found similar patterns. IMPLICATIONS: Patients with PE prescribed rivaroxaban had similar PE-related outcomes, but fewer HACs and lesser total costs, than did patients on SOC.

Leveraging cell type specific regulatory regions to detect SNPs associated with tissue factor pathway inhibitor plasma levels.

Tissue factor pathway inhibitor (TFPI) regulates the formation of intravascular blood clots, which manifest clinically as ischemic heart disease, ischemic stroke, and venous thromboembolism (VTE). TFPI plasma levels are heritable, but the genetics underlying TFPI plasma level variability are poorly understood. Herein we report the first genome-wide association scan (GWAS) of TFPI plasma levels, conducted in 251 individuals from five extended French-Canadian Families ascertained on VTE. To improve discovery, we also applied a hypothesis-driven (HD) GWAS approach that prioritized single nucleotide polymorphisms (SNPs) in (1) hemostasis pathway genes, and (2) vascular endothelial cell (EC) regulatory regions, which are among the highest expressers of TFPI. Our GWAS identified 131 SNPs with suggestive evidence of association (P-value < 5 × 10-8 ), but no SNPs reached the genome-wide threshold for statistical significance. Hemostasis pathway genes were not enriched for TFPI plasma level associated SNPs (global hypothesis test P-value = 0.147), but EC regulatory regions contained more TFPI plasma level associated SNPs than expected by chance (global hypothesis test P-value = 0.046). We therefore stratified our genome-wide SNPs, prioritizing those in EC regulatory regions via stratified false discovery rate (sFDR) control, and reranked the SNPs by q-value. The minimum q-value was 0.27, and the top-ranked SNPs did not show association evidence in the MARTHA replication sample of 1,033 unrelated VTE cases. Although this study did not result in new loci for TFPI, our work lays out a strategy to utilize epigenomic data in prioritization schemes for future GWAS studies.

Pulmonary embolism: Epidemiology and registries.

Real-life data is important in understanding the needs of patients in routine clinical practice, particularly owing to the fact that almost a quarter of patients with venous thromoboembolism (VTE) have at least one exclusion criterion preventing their recruitment into randomized clinical trials. The Registro Informatizado de Enfermedad Trombo Embólica (RIETE) registry is an ongoing, international, multicentre, prospective registry of consecutive patients presenting with acute VTE. In this chapter, we summarized some of the most relevant data concerning the epidemiology of VTE in the RIETE registry.

Validity of standard gamble estimated quality of life in acute venous thrombosis.

INTRODUCTION: The standard gamble is considered the 'gold standard' technique for measuring quality of life. We recently used the standard gamble to estimate quality of life in acute venous thrombosis, and found unexpected variability in the responses. The current study aimed to explore the reasons for variability by comparing the standard gamble technique in patients with acute venous thrombosis to other quality of life measurement tools. MATERIALS AND METHODS: Thrombosis clinic patients treated for venous thrombosis were eligible to participate. Patients evaluated their current health state by performing a standard gamble interview, reporting on a visual analogue scale, completing the SF-36 and disease specific questionnaires (PEmb-Qol and VEINES-QOL/Sym). Validity was assessed by correlating the standard gamble utilities with the other methods. Test-retest reliability, responsiveness and acceptability were also assessed. RESULTS: Forty-four patients were interviewed, with 16 attending for a repeat interview. The median standard gamble utility was 0.97 (0.84-1.0), SF-6D 0.64 (0.59 - 0.80) and visual analogue score 70 (60 - 80). Participants with pulmonary embolism had lower standard gamble estimates than those with deep vein thrombosis. There was good discriminant validity in that the standard gamble estimates were not associated with risk taking behavior, negative outlook, sex or education. Test-retest reliability with the standard gamble was moderate and there was evidence of a ceiling effect. CONCLUSIONS: Standard gamble utilities are higher than other methods of measuring quality of life in venous thrombosis. The choice of utility values adopted in studies will impact on future economic studies.

Edoxaban versus warfarin for the treatment of symptomatic venous thromboembolism.

BACKGROUND: Whether the oral factor Xa inhibitor edoxaban can be an alternative to warfarin in patients with venous thromboembolism is unclear. METHODS: In a randomized, double-blind, noninferiority study, we randomly assigned patients with acute venous thromboembolism, who had initially received heparin, to receive edoxaban at a dose of 60 mg once daily, or 30 mg once daily (e.g., in the case of patients with creatinine clearance of 30 to 50 ml per minute or a body weight below 60 kg), or to receive warfarin. Patients received the study drug for 3 to 12 months. The primary efficacy outcome was recurrent symptomatic venous thromboembolism. The principal safety outcome was major or clinically relevant nonmajor bleeding. RESULTS: A total of 4921 patients presented with deep-vein thrombosis, and 3319 with a pulmonary embolism. Among patients receiving warfarin, the time in the therapeutic range was 63.5%. Edoxaban was noninferior to warfarin with respect to the primary efficacy outcome, which occurred in 130 patients in the edoxaban group (3.2%) and 146 patients in the warfarin group (3.5%) (hazard ratio, 0.89; 95% confidence interval [CI], 0.70 to 1.13; P<0.001 for noninferiority). The safety outcome occurred in 349 patients (8.5%) in the edoxaban group and 423 patients (10.3%) in the warfarin group (hazard ratio, 0.81; 95% CI, 0.71 to 0.94; P=0.004 for superiority). The rates of other adverse events were similar in the two groups. A total of 938 patients with pulmonary embolism had right ventricular dysfunction, as assessed by measurement of N-terminal pro-brain natriuretic peptide levels; the rate of recurrent venous thromboembolism in this subgroup was 3.3% in the edoxaban group and 6.2% in the warfarin group (hazard ratio, 0.52; 95% CI, 0.28 to 0.98). CONCLUSIONS: Edoxaban administered once daily after initial treatment with heparin was noninferior to high-quality standard therapy and caused significantly less bleeding in a broad spectrum of patients with venous thromboembolism, including those with severe pulmonary embolism. (Funded by Daiichi-Sankyo; Hokusai-VTE ClinicalTrials.gov number, NCT00986154.).

Oral rivaroxaban for the treatment of symptomatic pulmonary embolism.

BACKGROUND: A fixed-dose regimen of rivaroxaban, an oral factor Xa inhibitor, has been shown to be as effective as standard anticoagulant therapy for the treatment of deep-vein thrombosis, without the need for laboratory monitoring. This approach may also simplify the treatment of pulmonary embolism. METHODS: In a randomized, open-label, event-driven, noninferiority trial involving 4832 patients who had acute symptomatic pulmonary embolism with or without deep-vein thrombosis, we compared rivaroxaban (15 mg twice daily for 3 weeks, followed by 20 mg once daily) with standard therapy with enoxaparin followed by an adjusted-dose vitamin K antagonist for 3, 6, or 12 months. The primary efficacy outcome was symptomatic recurrent venous thromboembolism. The principal safety outcome was major or clinically relevant nonmajor bleeding. RESULTS: Rivaroxaban was noninferior to standard therapy (noninferiority margin, 2.0; P=0.003) for the primary efficacy outcome, with 50 events in the rivaroxaban group (2.1%) versus 44 events in the standard-therapy group (1.8%) (hazard ratio, 1.12; 95% confidence interval [CI], 0.75 to 1.68). The principal safety outcome occurred in 10.3% of patients in the rivaroxaban group and 11.4% of those in the standard-therapy group (hazard ratio, 0.90; 95% CI, 0.76 to 1.07; P=0.23). Major bleeding was observed in 26 patients (1.1%) in the rivaroxaban group and 52 patients (2.2%) in the standard-therapy group (hazard ratio, 0.49; 95% CI, 0.31 to 0.79; P=0.003). Rates of other adverse events were similar in the two groups. CONCLUSIONS: A fixed-dose regimen of rivaroxaban alone was noninferior to standard therapy for the initial and long-term treatment of pulmonary embolism and had a potentially improved benefit-risk profile. (Funded by Bayer HealthCare and Janssen Pharmaceuticals; EINSTEIN-PE ClinicalTrials.gov number, NCT00439777.).

Oral rivaroxaban for symptomatic venous thromboembolism.

BACKGROUND: Rivaroxaban, an oral factor Xa inhibitor, may provide a simple, fixed-dose regimen for treating acute deep-vein thrombosis (DVT) and for continued treatment, without the need for laboratory monitoring. METHODS: We conducted an open-label, randomized, event-driven, noninferiority study that compared oral rivaroxaban alone (15 mg twice daily for 3 weeks, followed by 20 mg once daily) with subcutaneous enoxaparin followed by a vitamin K antagonist (either warfarin or acenocoumarol) for 3, 6, or 12 months in patients with acute, symptomatic DVT. In parallel, we carried out a double-blind, randomized, event-driven superiority study that compared rivaroxaban alone (20 mg once daily) with placebo for an additional 6 or 12 months in patients who had completed 6 to 12 months of treatment for venous thromboembolism. The primary efficacy outcome for both studies was recurrent venous thromboembolism. The principal safety outcome was major bleeding or clinically relevant nonmajor bleeding in the initial-treatment study and major bleeding in the continued-treatment study. RESULTS: The study of rivaroxaban for acute DVT included 3449 patients: 1731 given rivaroxaban and 1718 given enoxaparin plus a vitamin K antagonist. Rivaroxaban had noninferior efficacy with respect to the primary outcome (36 events [2.1%], vs. 51 events with enoxaparin-vitamin K antagonist [3.0%]; hazard ratio, 0.68; 95% confidence interval [CI], 0.44 to 1.04; P<0.001). The principal safety outcome occurred in 8.1% of the patients in each group. In the continued-treatment study, which included 602 patients in the rivaroxaban group and 594 in the placebo group, rivaroxaban had superior efficacy (8 events [1.3%], vs. 42 with placebo [7.1%]; hazard ratio, 0.18; 95% CI, 0.09 to 0.39; P<0.001). Four patients in the rivaroxaban group had nonfatal major bleeding (0.7%), versus none in the placebo group (P=0.11). CONCLUSIONS: Rivaroxaban offers a simple, single-drug approach to the short-term and continued treatment of venous thrombosis that may improve the benefit-to-risk profile of anticoagulation. (Funded by Bayer Schering Pharma and Ortho-McNeil; ClinicalTrials.gov numbers, NCT00440193 and NCT00439725.).