External validation of the ADA score for predicting thrombosis among acutely ill hospitalized medical patients from the APEX Trial.

The ADA (Age-D-dimer-Albumin) score was developed to identify hospitalized patients at an increased risk for thrombosis in the coronavirus infectious disease-19 (COVID-19) setting. The study aimed to validate the ADA score for predicting thrombosis in a non-COVID-19 medically ill population from the APEX trial. The APEX trial was a multinational, randomized trial that evaluated the efficacy and safety of betrixaban vs. enoxaparin among acutely ill hospitalized patients at risk for venous thromboembolism. The study endpoints included the composite of arterial or venous thrombosis and its components. Metrics of model calibration and discrimination were computed for assessing the performance of the ADA score as compared to the IMPROVE score, a well-validated VTE risk assessment model. Among 7,119 medical inpatients, 209 (2.9%) had a thrombosis event up to 77 days of follow-up. The ADA score demonstrated good calibration for both arterial and venous thrombosis, whereas the IMPROVE score had adequate calibration for venous thrombosis (p > 0.05 from the Hosmer-Lemeshow test). For discriminating arterial and venous thrombosis, there was no significant difference between the ADA vs. IMPROVE score (c statistic = 0.620 [95% CI: 0.582 to 0.657] vs. 0.590 [95% CI: 0.556 to 0.624]; ∆ c statistic = 0.030 [95% CI: -0.022 to 0.081]; p = 0.255). Similarly, for discriminating arterial thrombosis, there was no significant difference between the ADA vs. IMPROVE score (c statistic = 0.582 [95% CI: 0.534 to 0.629] vs. 0.609 [95% CI: 0.564 to 0.653]; ∆ c statistic = -0.027 [95% CI: -0.091 to 0.036]; p = 0.397). For discriminating venous thrombosis, the ADA score was modestly superior to the IMPROVE score (c statistic = 0.664 [95% CI: 0.607 to 0.722] vs. 0.573 [95% CI: 0.521 to 0.624]; ∆ c statistic = 0.091 [95% CI: 0.011 to 0.172]; p = 0.026). The ADA score had a higher sensitivity (0.579 [95% CI: 0.512 to 0.646]; vs. 0.440 [95% CI: 0.373 to 0.507]) but lower specificity (0.625 [95% CI: 0.614 to 0.637] vs. 0.747 [95% CI: 0.737 to 0.758]) than the IMPROVE score for predicting thrombosis. Among acutely ill hospitalized medical patients enrolled in the APEX trial, the ADA score demonstrated good calibration but suboptimal discrimination for predicting thrombosis. The findings support the use of either the ADA or IMPROVE score for thrombosis risk assessment. The applicability of the ADA score to non-COVID-19 populations warrants further research.Clinical Trial Registration: http://www.clinicaltrials.gov . Unique identifier: NCT01583218.

Extended prophylaxis of venous thromboembolism with betrixaban in acutely ill medical patients with and without cancer: insights from the APEX trial.

Acutely ill medical patients with cancer are at increased risk of venous thromboembolism (VTE). Thromboprophylaxis is recommended in the presence of cancer, but its safety is not known. The aim of this study was to assess the efficacy and safety of extended prophylaxis with betrixaban in cancer patients enrolled in the APEX trial. APEX was a randomized, double-blind trial comparing oral betrixaban 80 mg qd administered for 35-42 days with subcutaneous enoxaparin 40 mg qd administered for 10 ± 4 days. Patients with acute medical illness and a history of cancer or active cancer were eligible for inclusion. Primary efficacy outcome was VTE (composite of symptomatic VTE and asymptomatic proximal deep vein thrombosis); primary safety outcome was major bleeding. Of 7513 patients enrolled in the APEX trial, 959 patients (12.8%), 499 randomized to betrixaban and 460 to enoxaparin, had cancer. The primary efficacy outcome occurred in 5.7% of cancer patients treated with betrixaban and in 6.2% treated with enoxaparin (p = 0.95). No significant interaction according to the presence or absence of cancer was observed (p = 0.36). Major bleeding events occurred in 0.8% of patients in the betrixaban group and in 0% in the enoxaparin group (p = 0.13), with no significant interaction (p = 0.07). The composite of major and clinically relevant non-major bleeds was similar between the two groups (2.9% and 2.0%, respectively, RR 1.43, 95% CI 0.63-3.27). Betrixaban was similarly effective in the reduction of VTE among subjects with and without cancer. The incidence of major bleeding was similarly low.

Extended Thromboprophylaxis with Betrixaban in Acutely Ill Medical Patients.

BACKGROUND: Patients with acute medical illnesses are at prolonged risk for venous thrombosis. However, the appropriate duration of thromboprophylaxis remains unknown. METHODS: Patients who were hospitalized for acute medical illnesses were randomly assigned to receive subcutaneous enoxaparin (at a dose of 40 mg once daily) for 10±4 days plus oral betrixaban placebo for 35 to 42 days or subcutaneous enoxaparin placebo for 10±4 days plus oral betrixaban (at a dose of 80 mg once daily) for 35 to 42 days. We performed sequential analyses in three prespecified, progressively inclusive cohorts: patients with an elevated d-dimer level (cohort 1), patients with an elevated d-dimer level or an age of at least 75 years (cohort 2), and all the enrolled patients (overall population cohort). The statistical analysis plan specified that if the between-group difference in any analysis in this sequence was not significant, the other analyses would be considered exploratory. The primary efficacy outcome was a composite of asymptomatic proximal deep-vein thrombosis and symptomatic venous thromboembolism. The principal safety outcome was major bleeding. RESULTS: A total of 7513 patients underwent randomization. In cohort 1, the primary efficacy outcome occurred in 6.9% of patients receiving betrixaban and 8.5% receiving enoxaparin (relative risk in the betrixaban group, 0.81; 95% confidence interval [CI], 0.65 to 1.00; P=0.054). The rates were 5.6% and 7.1%, respectively (relative risk, 0.80; 95% CI, 0.66 to 0.98; P=0.03) in cohort 2 and 5.3% and 7.0% (relative risk, 0.76; 95% CI, 0.63 to 0.92; P=0.006) in the overall population. (The last two analyses were considered to be exploratory owing to the result in cohort 1.) In the overall population, major bleeding occurred in 0.7% of the betrixaban group and 0.6% of the enoxaparin group (relative risk, 1.19; 95% CI, 0.67 to 2.12; P=0.55). CONCLUSIONS: Among acutely ill medical patients with an elevated d-dimer level, there was no significant difference between extended-duration betrixaban and a standard regimen of enoxaparin in the prespecified primary efficacy outcome. However, prespecified exploratory analyses provided evidence suggesting a benefit for betrixaban in the two larger cohorts. (Funded by Portola Pharmaceuticals; APEX ClinicalTrials.gov number, NCT01583218.).

Inverse relationship of serum albumin to the risk of venous thromboembolism among acutely ill hospitalized patients: Analysis from the APEX trial.

Hypoalbuminemia is a common finding and independent predictor for unfavorable prognosis. The prognostic value of albumin measurement for short-term VTE prediction in hospitalized patients remains unclear. In the APEX trial (ClinicalTrials.gov identifier: NCT01583218), medical inpatients were randomized to receive either extended-duration betrixaban or shorter-duration enoxaparin and followed for 77 days. Baseline albumin concentrations were obtained in 7266 subjects with evaluable VTE endpoints. The association of baseline albumin to VTE was assessed, with adjustment for patient characteristics, thromboprophylaxis, and biomarkers for fibrinolysis and inflammation (ie, D-dimer and C-reactive protein [CRP]). VTE risk refinement was evaluated by incorporation of albumin to well-validated risk assessment models. A stepwise increase in the risk of VTE (P < .0001) was observed with lower levels of albumin. Patients at the bottom albumin quartile (<35 g/L) had a two-fold greater odds for developing VTE compared with the top quartile (≥42 g/L) (OR = 2.119 [95% CI, 1.592-2.820]; adjusted OR = 2.079 [1.485-2.911]). The odds for VTE increased by 1.368 (95% CI, 1.240-1.509) times per SD decrement of albumin (5.24 g/L). Compared with the propensity score-matched pairs of patients with albumin ≥35 g/L, patients with albumin <35 g/L had a greater risk of VTE (OR = 1.623 [1.260-2.090]; adjusted OR = 1.658 [1.209-2.272]). Albumin measurement also refined VTE risk discrimination and reclassification after inclusion in the risk assessment models. In conclusion, acutely ill hospitalized patients with low serum albumin had an increased VTE risk through 77 days. VTE risk assessment models for medical inpatients should consider incorporation of baseline albumin measurement.

Evaluation of unmet clinical needs in prophylaxis and treatment of venous thromboembolism in at-risk patient groups: pregnancy, elderly and obese patients.

BACKGROUND: Venous thromboembolism (VTE) accounts for an estimated 900,000 cases per year in the US alone and constitutes a considerable burden on healthcare systems across the globe. OBJECTIVE: To understand why the burden is so high, qualitative and quantitative research was carried out to gain insights from experts, guidelines and published studies on the unmet clinical needs and therapeutic strategies in VTE prevention and treatment in three populations identified as being at increased risk of VTE and in whom VTE prevention and treatment were regarded as suboptimal: pregnant women, the elderly and obese patients. METHODOLOGY: A gap analysis methodology was created to highlight unmet needs in VTE management and to discover the patient populations considered most at risk. A questionnaire was devised to guide qualitative interviews with 44 thrombosis and haemostasis experts, and a review of the literature on VTE in the specific patient groups from 2015 to 2017 was completed. This was followed by a Think Tank meeting where the results from the research were discussed. RESULTS: This review highlights the insights gained and examines in detail the unmet needs with regard to VTE risk-assessment tools, biomarkers, patient stratification methods, and anticoagulant and dosing regimens in pregnant women, the elderly and obese patients. CONCLUSIONS: Specifically, in pregnant women at high risk of VTE, low-molecular-weight heparin (LMWH) is the therapy of choice, but it remains unclear how to use anticoagulants when VTE risk is intermediate. In elderly patients, evaluation of the benefit of VTE prophylaxis against the bleeding risk is particularly important, and a head-to-head comparison of efficacy and safety of LMWH versus direct oral anticoagulants is needed. Finally, in obese patients, lack of guidance on anticoagulant dose adjustment to body weight has emerged as a major obstacle in effective prophylaxis and treatment of VTE.

Evaluation of unmet clinical needs in prophylaxis and treatment of venous thromboembolism in high-risk patient groups: cancer and critically ill.

BACKGROUND: Clinical practice shows that venous thromboembolism (VTE) presents a substantial burden in medical patients, and awareness and advocacy for its primary and secondary prevention remains inadequate. Specific patient populations, such as those with cancer and the critically ill, show elevated risk for VTE, bleeding or both, and significant gaps in VTE prophylaxis and treatment exist in these groups. OBJECTIVE: To present novel insights and consolidated evidence collected from experts, clinical practice guidelines and original studies on the unmet needs in thromboprophylaxis, and on the treatment of VTE in two high-risk patient groups: patients with cancer and the critically ill. METHODOLOGY: To identify specific unmet needs in the management of VTE, a methodology was designed and implemented that assessed gaps in prophylaxis and treatment of VTE through interviews with 44 experts in the field of thrombosis and haemostasis, and through a review of current guidelines and seminal studies to substantiate the insights provided by the experts. The research findings were then analysed, discussed and consolidated by a multidisciplinary group of experts. RESULTS: The gap analysis methodology identified shortcomings in the VTE risk assessment tools, patient stratification approaches for prophylaxis, and the suboptimal use of anticoagulants for primary prophylaxis and treatment. CONCLUSIONS: Specifically, patients with cancer need better VTE risk assessment tools to tailor primary thromboprophylaxis to tumour types and disease stages, and the potential for drug-drug interactions needs to be considered. In critically ill patients, unfractionated heparin is not advised as a first-line treatment option, and the strength of evidence is increasing for direct oral anticoagulants as a treatment option over low-molecular-weight heparins.

Increased benefit of betrixaban among patients with a history of venous thromboembolism: a post-hoc analysis of the APEX trial.

Hospitalized acute medically ill patients with a history of venous thromboembolism (VTE) are at increased risk for recurrent VTE. We characterized the efficacy and safety of betrixaban for prevention of recurrent VTE in these high risk patients. The APEX trial randomized 7513 acutely ill hospitalized medical patients at risk for developing VTE to receive either betrixaban for 35-42 days or enoxaparin for 10 ± 4 days to prevent VTE. This exploratory post-hoc analysis assessed the efficacy and safety of betrixaban versus enoxaparin among subjects with and without prior VTE. Time-to-multiple symptomatic VTE events was also calculated. Approximately 8% of subjects in both arms had prior VTE, which was associated with a fourfold increase in adjusted risk of VTE [MV OR 4.03, 95% CI 3.06-5.30, p < 0.001]. Betrixaban reduced VTE compared with enoxaparin among subjects with prior VTE [32 (10.4%) vs. 55 (18.9%), RR 0.57, 95% CI 0.38-0.86, p = 0.006, ARR 8.5%, NNT 12] and without prior VTE [133 (3.9%) vs. 168 (4.9%), RR 0.79, 95% CI 0.64-0.99, p = 0.042, ARR 1.0%, NNT 100] (interaction p > 0.05). Additionally, four subjects in the enoxaparin arm and one subject in the betrixaban arm experienced a recurrent VTE. Compared with enoxaparin, betrixaban use was associated with reduction of recurrent VTE events through the active treatment period [36 vs. 57, HR 0.63, 95% CI 0.41-0.97, p = 0.045] and through the end of study [38 vs. 71, HR 0.54, 95% CI 0.36-0.81, p = 0.004]. Prior VTE is associated with a fourfold increase in the risk of VTE among hospitalized medically ill patients. Only 12 such patients would need to be treated with betrixaban versus enoxaparin to prevent an additional VTE endpoint. Betrixaban reduced not only the first but also all recurrent VTE events in a time-to-any-event analysis. TRIAL REGISTRATION: http://www.clinicaltrials.gov , Unique identifier: NCT01583218.

N-terminal pro-B-type natriuretic peptide and the risk of stroke among patients hospitalized with acute heart failure: an APEX trial substudy.

BACKGROUND: Among patients hospitalized with acute heart failure (HF), the prognostic value of N-terminal pro-B-type natriuretic peptide (NT-proBNP) in short-term stroke prediction remains unclear. METHODS: In the APEX trial, 7513 patients hospitalized for an acute medical illness were randomized to receive either extended-duration betrixaban (80 mg once daily for 35-42 days) or standard-of-care enoxaparin (40 mg once daily for 10 ± 4 days) for venous thromboprophylaxis. Baseline NT-proBNP concentrations were obtained in 3261 patients admitted for HF. Stroke events were adjudicated by an independent clinical events committee blinded to thromboprophylaxis allocation. The association of NT-proBNP level and other risk factors and biomarkers with stroke was assessed at 77 days after randomization. RESULTS: In univariate analysis, the risk of stroke at 77 days was associated with baseline NT-proBNP (HR 3.63 [95% CI 1.47-8.99]; P = 0.005), D-dimer (HR 2.73 [95% CI 1.03-7.20]; P = 0.043), and hsCRP (HR 3.03 [95% CI 1.36-6.75]; P = 0.007). In multivariable analysis adjusting for hsCRP and thromboprophylaxis, NT-proBNP was associated with the risk of stroke (adjusted HR 3.64 [95% CI 1.35-9.83]; P = 0.011). The interaction of NT-proBNP with the treatment effect was not significant (Pint = 0.30). CONCLUSIONS: Baseline NT-proBNP concentration was associated with short-term stroke among patients hospitalized with acute HF. Stroke risk assessment models should consider incorporation of NT-proBNP measurement.

Competing risk analysis in a large cardiovascular clinical trial: An APEX substudy.

Competing risk methods are time-to-event analyses that account for fatal and/or nonfatal events that may potentially alter or prevent a subject from experiencing the primary endpoint. Competing risk methods may provide a more accurate and less biased estimate of the incidence of an outcome but are rarely applied in cardiology trials. APEX investigated the efficacy of extended-duration betrixaban versus standard-duration enoxaparin to prevent a composite of symptomatic deep-vein thrombosis (proximal or distal), nonfatal pulmonary embolism, or venous thromboembolism (VTE)-related death in acute medically ill patients (n = 7513). The aim of the current analysis was to determine the efficacy of betrixaban vs standard-duration enoxaparin accounting for non-VTE-related deaths using the Fine and Gray method for competing risks. The proportion of non-VTE-related death was similar in both the betrixaban (133, 3.6%) and enoxaparin (136, 3.7%) arms, P = .85. Both the traditional Kaplan-Meier method and the Fine and Gray method accounting for non-VTE-related death as a competing risk showed equal reduction of VTE events when comparing betrixaban to enoxaparin (HR/SHR = 0.65, 95% 0.42-0.99, P = 0.046). Due to the similar proportion of non-VTE-related deaths in both treatment arms and the use of a univariate model, the Fine and Gray method provided identical results to the traditional Cox model. Using the Fine and Gray method in addition to the traditional Cox proportional hazards method can indicate whether the presence of a competing risk, which is dependent of the outcome, altered the risk estimate.

Rivaroxaban for thromboprophylaxis in acutely ill medical patients.

BACKGROUND: The clinically appropriate duration of thromboprophylaxis in hospitalized patients with acute medical illnesses is unknown. In this multicenter, randomized, double-blind trial, we evaluated the efficacy and safety of oral rivaroxaban administered for an extended period, as compared with subcutaneous enoxaparin administered for a standard period, followed by placebo. METHODS: We randomly assigned patients 40 years of age or older who were hospitalized for an acute medical illness to receive subcutaneous enoxaparin, 40 mg once daily, for 10±4 days and oral placebo for 35±4 days or to receive subcutaneous placebo for 10±4 days and oral rivaroxaban, 10 mg once daily, for 35±4 days. The primary efficacy outcomes were the composite of asymptomatic proximal or symptomatic venous thromboembolism up to day 10 (noninferiority test) and up to day 35 (superiority test). The principal safety outcome was the composite of major or clinically relevant nonmajor bleeding. RESULTS: A total of 8101 patients underwent randomization. A primary efficacy outcome event occurred in 78 of 2938 patients (2.7%) receiving rivaroxaban and 82 of 2993 patients (2.7%) receiving enoxaparin at day 10 (relative risk with rivaroxaban, 0.97; 95% confidence interval [CI], 0.71 to 1.31; P=0.003 for noninferiority) and in 131 of 2967 patients (4.4%) who received rivaroxaban and 175 of 3057 patients (5.7%) who received enoxaparin followed by placebo at day 35 (relative risk, 0.77; 95% CI, 0.62 to 0.96; P=0.02). A principal safety outcome event occurred in 111 of 3997 patients (2.8%) in the rivaroxaban group and 49 of 4001 patients (1.2%) in the enoxaparin group at day 10 (P<0.001) and in 164 patients (4.1%) and 67 patients (1.7%) in the respective groups at day 35 (P<0.001). CONCLUSIONS: In acutely ill medical patients, rivaroxaban was noninferior to enoxaparin for standard-duration thromboprophylaxis. Extended-duration rivaroxaban reduced the risk of venous thromboembolism. Rivaroxaban was associated with an increased risk of bleeding. (Funded by Bayer HealthCare Pharmaceuticals and Janssen Research and Development; MAGELLAN ClinicalTrials.gov number, NCT00571649.).

Predicting the risk of venous thromboembolism in patients hospitalized with heart failure.

BACKGROUND: Whether heart failure (HF) increases the risk of venous thromboembolism (VTE) is not well established. In the phase III MAGELLAN (Multicenter, rAndomized, parallel Group Efficacy and safety study for the prevention of venous thromboembolism in hospitalized medically iLL patients comparing rivaroxabAN with enoxaparin) trial, extended-duration rivaroxaban was compared with standard-duration enoxaparin followed by placebo for VTE prevention in 8101 hospitalized acutely ill patients with or without HF. The aim of this analysis was to evaluate the relationship between HF severity and the risk of VTE in MAGELLAN patients. METHODS AND RESULTS: Hospitalized patients diagnosed with HF were included according to New York Heart Association class III or IV at admission (n=2593). HF severity was determined by N-terminal probrain natriuretic peptide (NT-proBNP) plasma concentrations (median 1904 pg/mL). Baseline plasma D-dimer concentrations ranged from 0.6 to 1.7 µg/L for the less and more severe HF subgroups. Patients with more severe HF had a greater incidence of VTE versus patients with less severe HF, with a significant trend up to Day 10 (4.3% versus 2.2%; P=0.0108) and Day 35 (7.2% versus 4.1%; P=0.0150). Multivariable analysis confirmed that NT-proBNP concentration was associated with VTE risk up to Day 10 (P=0.017) and D-dimer concentration with VTE risk up to Day 35 (P=0.005). The association between VTE risk and HF severity that was observed in the enoxaparin/placebo group was not seen in the extended-duration rivaroxaban group. CONCLUSIONS: Patients with more severe HF, as defined by high NT-proBNP plasma concentration, were at increased risk of VTE. NT-proBNP may be useful to identify high short-term risk, whereas elevated D-dimer may be suggestive of high midterm risk. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00571649.

D-Dimer elevation and adverse outcomes.

D-Dimer is a biomarker of fibrin formation and degradation. While a D-dimer within normal limits is used to rule out the diagnosis of deep venous thrombosis and pulmonary embolism among patients with a low clinical probability of venous thromboembolism (VTE), the prognostic association of an elevated D-dimer with adverse outcomes has received far less emphasis. An elevated D-dimer is independently associated with an increased risk for incident VTE, recurrent VTE, and mortality. An elevated D-dimer is an independent correlate of increased mortality and subsequent VTE across a broad variety of disease states. Therefore, medically ill subjects in whom the D-dimer is elevated constitute a high risk subgroup in which the prospective evaluation of the efficacy and safety of antithrombotic therapy is warranted.

The design and rationale for the Acute Medically Ill Venous Thromboembolism Prevention with Extended Duration Betrixaban (APEX) study.

Randomized clinical trials have identified a population of acute medically ill patients who remain at risk for venous thromboembolism (VTE) beyond the standard duration of therapy and hospital discharge. The aim of the APEX study is to determine whether extended administration of oral betrixaban (35-42 days) is superior to a standard short course of prophylaxis with subcutaneous enoxaparin (10 ± 4 days followed by placebo) in patients with known risk factors for post-discharge VTE. Patients initially are randomized to receive either betrixaban or enoxaparin (and matching placebo) in a double dummy design. Following a standard duration period of enoxaparin treatment (with placebo tablets) or betrixaban (with placebo injections), patients receive only betrixaban (or alternative matching placebo). Patients are considered for enrollment if they are older than 40 years, have a specified medical illness, and restricted mobility. They must also meet the APEX criteria for increased VTE risk (aged ≥75 years, baseline D-Dimer ≥2× upper the limit of "normal", or 2 additional ancillary risk factors for VTE). The primary efficacy end point is the composite of asymptomatic proximal deep venous thrombosis, symptomatic deep venous thrombosis, non-fatal (pulmonary embolus) pulmonary embolism, or VTE-related death through day 35. The primary safety outcome is the occurrence of major bleeding. We hypothesize that extended duration betrixaban VTE prophylaxis will be safe and more effective than standard short duration enoxaparin in preventing VTE in acute medically ill patients with known risk factors for post hospital discharge VTE.

Venous thromboembolism risk in ischemic stroke patients receiving extended-duration enoxaparin prophylaxis: results from the EXCLAIM study.

BACKGROUND AND PURPOSE: The optimal duration of venous thromboembolism prophylaxis in acute stroke patients is unknown. This subanalysis of the Extended Prophylaxis for Venous ThromboEmbolism in Acutely Ill Medical Patients With Prolonged Immobilization (EXCLAIM) study investigated extended-duration thromboprophylaxis with enoxaparin, compared with placebo following standard-duration enoxaparin, in ischemic stroke patients. METHODS: Acutely ill medical patients with recently reduced mobility received open-label enoxaparin 40 mg for 10±4 days, and they were then randomized to double-blind enoxaparin 40 mg daily or placebo for further 28±4 days. Venous thromboembolism incidence (symptomatic/asymptomatic deep-vein thrombosis, symptomatic/fatal pulmonary embolism) up to day 28 after randomization and major bleeding rates up to 48 h after the last dose of study treatment were reported. RESULTS: In total, 389 of 5963 (6.5%) randomized patients had ischemic stroke: 198 received extended-duration prophylaxis and 191 placebo. Extended-duration prophylaxis reduced venous thromboembolism incidence versus placebo (2.4% versus 8.0%; absolute risk difference, -5.6%; 95% CI, -10.5% to -0.7%), but it was associated with an increase in major bleeding (1.5% versus 0% in enoxaparin and placebo groups; absolute risk difference, +1.5%; 95% CI, -0.2% to 3.2%). CONCLUSIONS: Extended-duration thromboprophylaxis with enoxaparin was associated with reduced venous thromboembolism risk and increased major bleeding in the subgroup of patients with ischemic stroke in the EXCLAIM study.

Venous thromboembolism in cirrhosis: a review of the literature.

Although hemorrhage has traditionally been regarded as the most significant hemostatic complication of liver disease, there is increasing recognition that hypercoagulability is a prominent aspect of cirrhosis. Identifying markers of coagulability and monitoring anticoagulation therapy in the setting of cirrhosis is problematic. The bleeding risk of venous thromboembolism (VTE) prophylaxis and treatment in patients with chronic liver disease is unclear and there are currently no recommendations to guide practice in this regard. In the present report, the mechanism of coagulation disturbance in chronic liver disease is reviewed with an examination of the evidence for an increased VTE risk in cirrhosis. Finally, the available evidence is assessed for prophylaxis and therapy of VTE in chronic liver disease, and the role it may play in decreasing clinical decompensation and improving survival.

Inverse relationship between body mass index and risk of venous thromboembolism among medically ill hospitalized patients: Observations from the APEX trial.

Obesity is associated with cardiovascular complications such as diabetes and hypertension. However, obesity and high body mass index (BMI) can also be linked to improved clinical outcomes in certain patient populations. This counterintuitive observation is called the "obesity paradox." The effect of BMI on the risk of developing venous thromboembolism (VTE) in acutely ill medical patients remains unclear. In the Acute Medically Ill VTE Prevention with Extended Duration Betrixaban (APEX) trial, acutely ill hospitalized medical patients were randomized to receive either extended-duration betrixaban or shorter-duration enoxaparin and followed for 77 days. A total of 7372 patients with evaluable VTE endpoints had BMI measured at baseline. The association between BMI and VTE risk was assessed after adjusting for potential confounders. The multivariable adjusted ORs of VTE risk associated with BMI levels referencing the median BMI value (15, 18.5, 28.3 [reference], 35, 40, 45) were: 2.82 (95% CI, 1.32-6.04, [change from 28.3 to 15]), 1.85 (95% CI, 1.14-2.99, [change from 28.3 to 18.5]), 1.30 (95% CI, 1.04-1.63, [change from 28.3 to 35]), 1.13 (95% CI, 0.84-1.52, [change from 28.3 to 40]), and 0.91 (95% CI, 0.57-1.47, [change from 28.3 to 45]), respectively (p = 0.022). In conclusion, acutely ill hospitalized patients with lower BMI had a higher VTE risk through 77 days, which appears to be a manifestation of the BMI paradox.

Extended-duration rivaroxaban thromboprophylaxis in acutely ill medical patients: MAGELLAN study protocol.

Patients with acute medical illnesses are at increased risk of venous thromboembolism (VTE), a significant cause of morbidity and mortality. Thromboprophylaxis is recommended in these patients but questions remain regarding the optimal duration of therapy. The aim of this study is to determine whether oral rivaroxaban is non-inferior to standard-duration (approximately 10 days) subcutaneous (s.c.) enoxaparin for the prevention of VTE in acutely ill medical patients, and whether extended-duration (approximately 5 weeks) rivaroxaban is superior to standard-duration enoxaparin. Patients aged 40 years or older and hospitalized for various acute medical illnesses with risk factors for VTE randomly receive either s.c. enoxaparin 40 mg once daily (od) for 10 ± 4 days or oral rivaroxaban 10 mg od for 35 ± 4 days. The primary efficacy outcomes are the composite of asymptomatic proximal deep vein thrombosis (DVT), symptomatic DVT, symptomatic non-fatal pulmonary embolism (PE), and VTE-related death up to day 10 + 4 and up to day 35 + 4. The primary safety outcome is the composite of treatment-emergent major bleeding and clinically relevant non-major bleeding. As of July 2010, 8,101 patients from 52 countries have been randomized. These patients have a broad range of medical conditions: approximately one-third were diagnosed with acute heart failure, just under one-third were diagnosed with acute infectious disease, and just under one-quarter were diagnosed with acute respiratory insufficiency. MAGELLAN will determine the efficacy, safety, and pharmacological profile of oral rivaroxaban for the prevention of VTE in a diverse population of medically ill patients and the potential of extended-duration therapy to reduce incidence of VTE.