Homoarginine and methylarginines independently predict long-term outcome in patients presenting with suspicion of venous thromboembolism.

Endogenous arginine derivatives homoarginine, asymmetric dimethylarginine (ADMA) and symmetric dimethyarginine (SDMA) are independent mortality predictors in atherosclerotic cardiovascular disease (CVD). Our study reports the first analysis, whether homoarginine, ADMA and SDMA predict venous thromboembolism (VTE) recurrence and overall mortality in patients with suspected acute VTE. We assessed serum levels of homoarginine, ADMA and SDMA by LC-MS/MS in 865 individuals from a prospective consecutive cohort of patients with clinical suspicion of VTE. The median follow-up time for mortality was 1196 days. VTE was confirmed by imaging in 418 patients and excluded in 447 patients. Low levels of homoarginine and high levels of ADMA or SDMA independently predicted all-cause mortality after adjustment for sex, age, oral anticoagulants, body mass index, arterial hypertension, diabetes mellitus, smoking, dyslipidemia, chronic heart failure, history of stroke, creatinine and cancer both in patients with VTE and without VTE. Interestingly, none of those parameters was predictive for VTE recurrence. We provide the first report that low circulating levels of homoarginine and high circulating levels of ADMA and SDMA independently predict all-cause mortality in patients with suspected VTE. These parameters might serve as markers of "frailty" and should be considered for future risk stratification approaches in this clinical population. Taking into account that homoarginine supplementation is protective in animal models of CVD and safe in healthy human volunteers, our study provides the basis for future homoarginine supplementation studies in patients with suspected VTE to investigate possible direct protective effects of homoarginine in this population.

Rationale and design for the study of rivaroxaban to reduce thrombotic events, hospitalization and death in outpatients with COVID-19: The PREVENT-HD study.

BACKGROUND: COVID-19 is associated with both venous and arterial thrombotic complications. While prophylactic anticoagulation is now widely recommended for hospitalized patients with COVID-19, the effectiveness and safety of thromboprophylaxis in outpatients with COVID-19 has not been established. STUDY DESIGN: PREVENT-HD is a double-blind, placebo-controlled, pragmatic, event-driven phase 3 trial to evaluate the efficacy and safety of rivaroxaban in symptomatic outpatients with laboratory-confirmed COVID-19 at risk for thrombotic events, hospitalization, and death. Several challenges posed by the pandemic have necessitated innovative approaches to clinical trial design, start-up, and conduct. Participants are randomized in a 1:1 ratio, stratified by time from COVID-19 confirmation, to either rivaroxaban 10 mg once daily or placebo for 35 days. The primary efficacy end point is a composite of symptomatic venous thromboembolism, myocardial infarction, ischemic stroke, acute limb ischemia, non-central nervous system systemic embolization, all-cause hospitalization, and all-cause mortality. The primary safety end point is fatal and critical site bleeding according to the International Society on Thrombosis and Haemostasis definition. Enrollment began in August 2020 and is expected to enroll approximately 4,000 participants to yield the required number of end point events. CONCLUSIONS: PREVENT-HD is a pragmatic trial evaluating the efficacy and safety of the direct oral anticoagulant rivaroxaban in the outpatient setting to reduce major venous and arterial thrombotic events, hospitalization, and mortality associated with COVID-19.

Prevalence and Predictors of Venous Thromboembolism or Mortality in Hospitalized COVID-19 Patients.

BACKGROUND: We aimed to identify the prevalence and predictors of venous thromboembolism (VTE) or mortality in hospitalized coronavirus disease 2019 (COVID-19) patients. METHODS: A retrospective cohort study of hospitalized adult patients admitted to an integrated health care network in the New York metropolitan region between March 1, 2020 and April 27, 2020. The final analysis included 9,407 patients with an overall VTE rate of 2.9% (2.4% in the medical ward and 4.9% in the intensive care unit [ICU]) and a VTE or mortality rate of 26.1%. Most patients received prophylactic-dose thromboprophylaxis. Multivariable analysis showed significantly reduced VTE or mortality with Black race, history of hypertension, angiotensin converting enzyme/angiotensin receptor blocker use, and initial prophylactic anticoagulation. It also showed significantly increased VTE or mortality with age 60 years or greater, Charlson Comorbidity Index (CCI) of 3 or greater, patients on Medicare, history of heart failure, history of cerebrovascular disease, body mass index greater than 35, steroid use, antirheumatologic medication use, hydroxychloroquine use, maximum D-dimer four times or greater than the upper limit of normal (ULN), ICU level of care, increasing creatinine, and decreasing platelet counts. CONCLUSION: In our large cohort of hospitalized COVID-19 patients, the overall in-hospital VTE rate was 2.9% (4.9% in the ICU) and a VTE or mortality rate of 26.1%. Key predictors of VTE or mortality included advanced age, increasing CCI, history of cardiovascular disease, ICU level of care, and elevated maximum D-dimer with a cutoff at least four times the ULN. Use of prophylactic-dose anticoagulation but not treatment-dose anticoagulation was associated with reduced VTE or mortality.

Rivaroxaban thromboprophylaxis in ambulatory patients with pancreatic cancer: Results from a pre-specified subgroup analysis of the randomized CASSINI study.

BACKGROUND: Pancreatic cancer patients are at risk for venous thromboembolism (VTE); the value of thromboprophylaxis has not been definitively established. METHODS: This trial randomized cancer patients initiating a new regimen and at high risk for VTE (Khorana score ≥2) to rivaroxaban 10 mg or placebo up to day 180. This analysis examined the subset of pancreatic cancer patients. The primary efficacy endpoint was the composite of symptomatic deep-vein thrombosis (DVT), asymptomatic proximal DVT, any pulmonary embolism, and VTE-related death. The primary safety endpoint was International Society on Thrombosis and Haemostasis-defined major bleeding. RESULTS: In total, 49/1080 (4.5%) patients enrolled had baseline VTE on screening, with higher rates (24/362 [6.6%]) in pancreatic cancer and they were not randomized. Of 841 randomized patients, 273 (32.5%) had pancreatic cancer; 155/273 (57% in each arm) completed the double-blind period. The primary endpoint occurred in 13/135 (9.6%) patients in the rivaroxaban group and in 18/138 (13.0%) in the placebo group (hazard ratio [HR] = 0.70; 95% CI, 0.34-1.43; P = .328) in up-to-day-180 period and 5/135 (3.7%) patients receiving rivaroxaban and 14/138 (10.1%) receiving placebo in the intervention period (HR = 0.35; 95% CI, 0.13-0.97; P = .034). Major bleeding was similar (2 [1.5%] receiving rivaroxaban and 3 [2.3%] receiving placebo). Correlative biomarker studies demonstrated significant decline in D-dimer (weeks 8 and 16) in patients randomized to rivaroxaban compared to placebo (P < .01). CONCLUSIONS: In ambulatory pancreatic cancer patients, rivaroxaban did not result in significantly lower incidence of VTE or VTE-related death in the 180-day period. During the intervention period, however, rivaroxaban substantially reduced VTE without increasing major bleeding, suggesting benefit of rivaroxaban prophylaxis in this setting. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT02555878.

DOACs Versus VKAs in Older Adults Treated for Acute Venous Thromboembolism: Systematic Review and Meta-Analysis.

BACKGROUND/OBJECTVES: Four direct-acting oral anticoagulants (DOACs) are currently approved by the Food and Drug Administration for the treatment of venous thromboembolism (VTE). Limited efficacy and safety data are available for their use in older adults (aged ≥75 years). METHODS: Medline, Cochrane Central Register of Controlled Trials, Embase, EBSCO, Web of Science, and CINAHL databases were searched for trials comparing DOACs with vitamin K antagonists (VKAs) for the treatment of VTE in older adults from inception through January 1, 2020. Meta-analysis was performed to assess the combined endpoint of recurrent VTE and related deaths and bleeding events (composite of major and clinically relevant nonmajor bleeding). The Mantel-Haenszel relative risk (RR) random effects model was used to pool results across studies. RESULTS: Six randomized controlled trials at low risk of bias met criteria for inclusion with a total of 3,665 patients aged 75 years and older with follow-up of 24 weeks or longer. Data for bleeding events were not available for dabigatran. Overall, DOACs had an improved efficacy over VKAs (RR = .56; 95% confidence interval [CI] = .38-.82). There was no statistically significant difference in the safety outcomes (RR = .77; 95% CI = .56-1.05). No significant heterogeneity was observed for efficacy outcome, and only moderate heterogeneity was observed for safety outcome. CONCLUSION: In older adults with VTE, DOACs appear to improve rates of recurrent VTE and VTE-related deaths compared with VKAs with similar bleeding outcomes.

Rivaroxaban or Enoxaparin in Nonmajor Orthopedic Surgery.

BACKGROUND: Nonmajor orthopedic surgery of the lower limbs that results in transient reduced mobility places patients at risk for venous thromboembolism. Rivaroxaban may be noninferior to enoxaparin with regard to the prevention of major venous thromboembolism in these patients. METHODS: In this international, parallel-group, randomized, double-blind, noninferiority trial, we randomly assigned adult patients undergoing lower-limb nonmajor orthopedic surgery who were considered to be at risk for venous thromboembolism on the basis of the investigator's judgment to receive either rivaroxaban or enoxaparin. The primary efficacy outcome of major venous thromboembolism was a composite of symptomatic distal or proximal deep-vein thrombosis, pulmonary embolism, or venous thromboembolism-related death during the treatment period or asymptomatic proximal deep-vein thrombosis at the end of treatment. A test for superiority was planned if rivaroxaban proved to be noninferior to enoxaparin. For all outcomes, multiple imputation was used to account for missing data. Prespecified safety outcomes included major bleeding (fatal, critical, or clinically overt bleeding or bleeding at the surgical site leading to intervention) and nonmajor clinically relevant bleeding. RESULTS: A total of 3604 patients underwent randomization; 1809 patients were assigned to receive rivaroxaban, and 1795 to receive enoxaparin. Major venous thromboembolism occurred in 4 of 1661 patients (0.2%) in the rivaroxaban group and in 18 of 1640 patients (1.1%) in the enoxaparin group (risk ratio with multiple imputation, 0.25; 95% confidence interval, 0.09 to 0.75; P<0.001 for noninferiority; P = 0.01 for superiority). The incidence of bleeding did not differ significantly between the rivaroxaban group and the enoxaparin group (1.1% and 1.0%, respectively, for major bleeding or nonmajor clinically relevant bleeding; 0.6% and 0.7%, respectively, for major bleeding). CONCLUSIONS: Rivaroxaban was more effective than enoxaparin in the prevention of venous thromboembolic events during a period of immobilization after nonmajor orthopedic surgery of the lower limbs. (Funded by Centre Hospitalier Universitaire de Saint-Etienne and Bayer; PRONOMOS ClinicalTrials.gov number, NCT02401594.).

Extended treatment with non-vitamin K antagonist oral anticoagulants versus low-molecular-weight heparins in cancer patients following venous thromboembolism. A pilot study.

BACKGROUND: Low-molecular-weight heparins (LMWH) are the drug of choice for treatment of cancer-associated thrombosis (CAT), however non-vitamin K antagonist oral anticoagulants (NOAC) seem to be a reasonable alternative. We investigated the safety and efficacy of NOAC versus LMWH in patients with a history of CAT. METHODS: In a prospective cohort study 128 consecutive patients with active cancer who experienced CAT were enrolled following LMWH treatment for ≥3 months. Symptomatic recurrent venous thromboembolism (VTE), bleeding and death were recorded during follow-up. RESULTS: 65 (50.8%) patients were switched to NOAC and 63 (49.2%) continued with LMWH. During a median follow-up of 17 (interquartile range, 15-21) months, recurrent VTE was observed in 6 (9.2%) patients on NOAC and in 12 (19.0%) on LMWH (hazard ratio [HR] 0.44, 95% confidence interval [CI] 0.16-1.16). The rate of major bleeding was 9.2% and 4.8%, respectively (HR 2.00, 95% CI 0.50-8.00). The median time to bleeding was shorter in patients on NOAC (3 [2.25-5.5] months) versus on LMWH (9 [6.5-13.0] months). The mortality rates were similar in both groups (15.4% versus 15.9%, respectively, HR 0.76, 95% CI 0.32-1.84). CONCLUSIONS: In patients following CAT, extended treatment with NOAC, compared with LMWH, appears to be associated with similar effectiveness and safety.

Long-term rivaroxaban for the treatment of acute venous thromboembolism in patients with active cancer in a prospective multicenter trial.

BACKGROUND/AIMS: Limited data are available regarding the efficacy of rivaroxaban for the treatment of cancer-associated venous thromboembolism (VTE). The aim of this study was to evaluate the effectiveness and safety of rivaroxaban for the treatment of VTE in active cancer patients. METHODS: In this prospective, multicenter, open-label trial (NCT01989845), we enrolled patients with active cancer and objectively diagnosed lower-extremity deep vein thrombosis, pulmonary embolism (PE), or both from November 2013 to June 2016. Active cancer was defined as a histologically confirmed malignancy, which was diagnosed or treated within the previous 6 months, or as a recurrent/ metastatic cancer. Patients received oral rivaroxaban 15 mg twice daily for first 3 weeks, followed by 20 mg once daily for 6 months. The primary outcome was the symptomatic recurrent VTE and the secondary outcomes included any recurrent VTE, major or clinically relevant non-major (CRNM) bleeding events, and overall mortality. All study outcomes were validated by blinded central adjudication. RESULTS: Of 124 patients enrolled, 110 (88.7%) had solid cancer, 93 (75.0%) had metastatic disease, and 110 (88.7%) were receiving chemotherapy or radiotherapy. During the 6-month study period, seven patients experienced symptomatic recurrent VTE (cumulative incidence, 5.9%), and two patients experienced incidental recurrent PE (cumulative incidence of any recurrent VTE, 7.6%). Major bleeding events occurred in six patients (cumulative incidence, 5.3%) and CRNM bleeding events in 11 patients (cumulative incidence, 10.2%). Twenty-eight patients (overall mortality, 24.0%) died. CONCLUSION: Rivaroxaban is effective and safe for the treatment of VTE in patients with active cancer.

Safety of In-Hospital Only Thromboprophylaxis after Fast-Track Total Hip and Knee Arthroplasty: A Prospective Follow-Up Study in 17,582 Procedures.

Most international guidelines recommend pharmacological thromboprophylaxis after total hip and knee arthroplasty (THA/TKA) for 10 to 35 days. However, a recent cohort study on fast-track THA and TKA questioned the need for prolonged thromboprophylaxis when length of stay (LOS) is ≤ 5 days. We aimed at re-investigating the incidence of venous thromboembolism (VTE) in fast-track THA and TKA with in-hospital only thromboprophylaxis when LOS was ≤ 5 days. Prospective cohort study from 1 December 2011 to 30 October 2015 on elective unilateral THA/TKA with in-hospital only thromboprophylaxis if LOS was ≤ 5 days. Prospective information on co-morbidity and complete 90-day follow-up through the Danish National Patient Registry and medical records. Patients with pre-operative use of anticoagulants were excluded. In per protocol analysis, 17,582 (95.5%) had LOS of ≤ 5 days (median, 2 [interquartile range, 2-3]) and in-hospital thromboprophylaxis only. Incidence of symptomatic VTE was 0.40%, consisting of 28 (0.16%) pulmonary embolisms (PEs), 38 (0.22%) deep vein thrombosis (DVT) and 4 (0.02%) combined DVT and PE. Two PEs (0.01%) were fatal. VTE-associated risk factors with in-hospital only thromboprophylaxis were age > 85 years, odds ratio (OR) of 3.74 (95% confidence interval: 1.15-12.14, p = 0.028), body mass index (BMI) of 35 to 40, OR of 2.55 (1.02-6.35, p = 0.045) and BMI > 40, OR of 3.28 (1.02-10.56, p = 0.046). In conclusion, 90-day incidence of VTE after fast-track THA and TKA with in-hospital thromboprophylaxis only was 0.40%. Prolonged thromboprophylaxis may be reserved for LOS > 5 days or specific high-risk patients, but requires further studies regarding optimal type and duration of thromboprophylaxis.

Rivaroxaban for Thromboprophylaxis after Hospitalization for Medical Illness.

BACKGROUND: Patients who are hospitalized for medical illness remain at risk for venous thromboembolism after discharge, but the role of extended thromboprophylaxis in the treatment of such patients is a subject of controversy. METHODS: In this randomized, double-blind trial, medically ill patients who were at increased risk for venous thromboembolism on the basis of a modified International Medical Prevention Registry on Venous Thromboembolism (IMPROVE) score of 4 or higher (scores range from 0 to 10, with higher scores indicating a higher risk of venous thromboembolism) or a score of 2 or 3 plus a plasma d-dimer level of more than twice the upper limit of the normal range (defined according to local laboratory criteria) were assigned at hospital discharge to either once-daily rivaroxaban at a dose of 10 mg (with the dose adjusted for renal insufficiency) or placebo for 45 days. The primary efficacy outcome was a composite of symptomatic venous thromboembolism or death due to venous thromboembolism. The principal safety outcome was major bleeding. RESULTS: Of the 12,024 patients who underwent randomization, 12,019 were included in the intention-to-treat analysis. The primary efficacy outcome occurred in 50 of 6007 patients (0.83%) who were given rivaroxaban and in 66 of 6012 patients (1.10%) who were given placebo (hazard ratio, 0.76; 95% confidence interval [CI], 0.52 to 1.09; P=0.14). The prespecified secondary outcome of symptomatic nonfatal venous thromboembolism occurred in 0.18% of patients in the rivaroxaban group and 0.42% of patients in the placebo group (hazard ratio, 0.44; 95% CI, 0.22 to 0.89). Major bleeding occurred in 17 of 5982 patients (0.28%) in the rivaroxaban group and in 9 of 5980 patients (0.15%) in the placebo group (hazard ratio, 1.88; 95% CI, 0.84 to 4.23). CONCLUSIONS: Rivaroxaban, given to medical patients for 45 days after hospital discharge, was not associated with a significantly lower risk of symptomatic venous thromboembolism and death due to venous thromboembolism than placebo. The incidence of major bleeding was low. (Funded by Janssen Research and Development; MARINER ClinicalTrials.gov number, NCT02111564 .).

All-Cause Mortality Risk with Direct Oral Anticoagulants and Warfarin in the Primary Treatment of Venous Thromboembolism.

Oral anticoagulants used for the primary treatment of venous thromboembolism (VTE) include warfarin and the more recently introduced direct oral anticoagulants (DOACs), including rivaroxaban, apixaban, dabigatran and edoxaban. Information on the comparative safety of these medications in routine clinical practice is lacking. We identified patients with diagnoses for VTE and prescriptions for oral anticoagulants using claims data from a large U.S. insurance database from 2012 to 2017. Marginal structural logistic models were used to examine associations between type of oral anticoagulant and risk of all-cause mortality. Of 62,431 enrolees in this analysis, 51% were female and the mean age was 61.9 years. Initial oral anticoagulant prescriptions were for warfarin (n = 35,704), rivaroxaban (n = 21,064) and apixaban (n = 5,663). A total of 1,791 deaths occurred within 6 months of the initial oral anticoagulant prescription. Risk of all-cause mortality was not associated with having a prescription for warfarin versus any DOAC or between any head-to-head DOAC comparisons. Also, associations generally did not vary when stratified by VTE type, sex, age, co-morbidities (including renal disease) or anti-platelet medication use. In this observational study, the associations with all-cause mortality comparing DOACs versus warfarin agree with results from previous clinical trials and observational studies, while the associations for head-to-head DOAC comparisons provide new information on the comparative safety of DOACs. Our findings suggest that other criteria such as patient preference, cost, recurrent VTE risk or bleeding risk should be used when determining the choice of anticoagulant for the primary treatment of VTE.

Safety and effectiveness of rivaroxaban and apixaban in patients with venous thromboembolism: a nationwide study.

Aims: To investigate the risk of all-cause mortality, recurrent venous thromboembolism (VTE), and hospitalized bleeding in patients with VTE treated with either rivaroxaban or apixaban. Methods and results: Using Danish nationwide registries, patients with VTE treated with rivaroxaban or apixaban in the period from 1 January 2015 to 30 June 2017 were identified. Standardized absolute risks were estimated based on outcome-specific Cox regression models, adjusted for potential confounders. A total of 8187 patients were included in the study, of which 1504 (18%) were treated with apixaban [50% males, median age 70 years; interquartile range (IQR) 56-80] and 6683 (82%) were treated with rivaroxaban (55% males, median age 67 years; IQR 53-76). The 180 days risk of all-cause mortality was 5.08% [95% confidence interval (95% CI) 4.08% to 6.08%)] in the apixaban group and 4.60% (95% CI 4.13% to 5.18%) in the rivaroxaban group [absolute risk difference: -0.48% (95% CI -1.49% to 0.72%)]. The 180 days risk of recurrent VTE was 2.16% (95% CI 1.49% to 2.88%) in the apixaban group and 2.22% (95% CI 1.89% to 2.52%) in the rivaroxaban group [absolute risk difference of 0.06% (95% CI -0.72% to 0.79%)]. The 180 days risk of hospitalized bleeding was 1.73% (95% CI 1.22% to 2.35%) for patients in the apixaban group and 1.89% (95% CI 1.56% to 2.20%) in the rivaroxaban group [absolute risk difference: 0.16% (95% CI -0.59% to 0.81%)]. Conclusion: In a nationwide cohort of 8187 patients with VTE treated with rivaroxaban or apixaban, there were no significant differences in the risks of all-cause mortality, recurrent VTE, or hospitalized bleeding.

Secondary prevention of recurrent venous thromboembolism after initial oral anticoagulation therapy in patients with unprovoked venous thromboembolism.

BACKGROUND: Currently, little evidence is available on the length and type of anticoagulation used for extended treatment for prevention of recurrent venous thromboembolism (VTE) in patients with unprovoked VTE who have completed initial oral anticoagulation therapy. OBJECTIVES: To compare the efficacy and safety of available oral therapeutic options (aspirin, warfarin, direct oral anticoagulants (DOACs)) for extended thromboprophylaxis in adults with a first unprovoked VTE, to prevent VTE recurrence after completion of an acceptable initial oral anticoagulant treatment period, as defined in individual studies. SEARCH METHODS: For this review, the Cochrane Vascular Information Specialist (CIS) searched the Specialised Register (March 2017) as well as the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 2). We also searched trials registries (March 2017) and reference lists of relevant articles. SELECTION CRITERIA: We included randomised controlled trials in which patients with a first, symptomatic, objectively confirmed, unprovoked VTE, who had been initially treated with anticoagulants, were randomised to extended prophylaxis (vitamin K antagonists (VKAs), antiplatelet agents, or DOACs) versus no prophylaxis or placebo. We also included trials that compared one type of extended prophylaxis versus another type of extended prophylaxis. DATA COLLECTION AND ANALYSIS: Two review authors independently selected studies, assessed quality, and extracted data. We resolved disagreements by discussion. MAIN RESULTS: Six studies with a combined total of 3436 participants met the inclusion criteria. Five studies compared extended prophylaxis versus placebo: three compared warfarin versus placebo, and two compared aspirin versus placebo. One study compared one type of extended prophylaxis (rivaroxaban) versus another type of extended prophylaxis (aspirin). For extended prophylaxis versus placebo, we downgraded the quality of the evidence for recurrent VTE and all-cause mortality to moderate owing to concerns arising from risks of selection and performance bias in individual studies. For all other outcomes in this review, we downgraded the quality of the evidence to low owing to concerns arising from risk of bias for the studies stated above, combined with concerns over imprecision. For extended prophylaxis versus other extended prophylaxis, we downgraded the quality of the evidence for recurrent VTE and major bleeding to moderate owing to concerns over imprecision. Risk of bias in the individual study was low.Meta-analysis showed that extended prophylaxis was no more effective than placebo in preventing VTE-related mortality (odds ratio (OR) 0.98, 95% confidence interval (CI) 0.14 to 6.98; 1862 participants; 4 studies; P = 0.98; low-quality evidence), recurrent VTE (OR 0.63, 95% CI 0.38 to 1.03; 2043 participants; 5 studies; P = 0.07; moderate-quality evidence), major bleeding (OR 1.84, 95% CI 0.87 to 3.85; 2043 participants; 5 studies; P = 0.86; low-quality evidence), all-cause mortality (OR 1.00, 95% CI 0.63 to 1.57; 2043 participants; 5 studies; P = 0.99; moderate-quality evidence), clinically relevant non-major bleeding (OR 1.78, 95% CI 0.59 to 5.33; 1672 participants; 4 studies; P = 0.30; low-quality evidence), stroke (OR 1.15, 95% CI 0.39 to 3.46; 1224 participants; 2 studies; P = 0.80; low-quality evidence), or myocardial infarction (OR 1.00, 95% CI 0.35 to 2.87; 1495 participants; 3 studies; P = 1.00; low-quality evidence).One study showed that the novel oral anticoagulant rivaroxaban was associated with fewer recurrent VTEs than aspirin (OR 0.28, 95% CI 0.15 to 0.54; 1389 participants; P = 0.0001; moderate-quality evidence). Data show no clear differences in the incidence of major bleeding between rivaroxaban and aspirin (OR 3.06, 95% CI 0.37 to 25.51; 1389 participants; P = 0.30; moderate-quality evidence) nor in the incidence of clinically relevant non-major bleeding (OR 0.84, 95% CI 0.37 to 1.94; 1389 participants; 1 study; P = 0.69; moderate-quality evidence). Data on VTE-related mortality, all-cause mortality, stroke, and myocardial infarction were not yet available for participants with unprovoked VTE and will be incorporated in future versions of the review. AUTHORS' CONCLUSIONS: Evidence is currently insufficient to permit definitive conclusions concerning the effectiveness and safety of extended thromboprophylaxis in prevention of recurrent VTE after initial oral anticoagulation therapy among participants with unprovoked VTE. Additional good-quality large-scale randomised controlled trials are required before firm conclusions can be reached.

Terapia anticoagulante no tromboembolismo venoso / Anticoagulant therapy in venous thromboembolism

Introdução: O tromboembolismo venoso (TEV), incluindo a embolia pulmonar (EP) e a trombose venosa profunda (TVP), é a terceira causa de mortalidade em todo o mundo. O diagnóstico ainda é subestimado nas emergências. Os fatores desencadeantes são bem definidos, o que auxilia a estratificação de risco e o diagnóstico de TEV provocada ou não e influenciará muito o tempo de tratamento. O aumento do ventrículo direito e de marcadores biológicos tem desempenhado grande papel no prognóstico. O quadro clínico é bem definido e tem várias ferramentas, tanto para o diagnóstico como para a estratificação de risco, tais como os critérios de Wells e de Genebra, além de outros. Os exames complementares atualmente estão bem definidos, com a angiografia pulmonar sendo o padrão de referência; porém, com a melhora da tecnologia e a alta sensibilidade e especificidade, a angiotomografia computadorizada ocupou um lugar de destaque. Outros exames ainda são importantes em várias situações, como o D-dímero e outros biomarcadores, a radiografia de tórax, a cintilografia de perfusão/ventilação, eletrocardiograma, ecocardiografia e doppler venoso de membros inferiores. Método: Neste artigo, revisamos aspectos básicos de epidemiologia, diagnóstico e estratificação de risco. O foco principal foi o tratamento com a terapia anticoagulante, sobre a qual revisamos os seis estudos clínicos descritos entre 2009 e 2013, que abordam os novos anticoagulantes orais, hoje denominados anticoagulantes orais diretos. Esses estudos têm desenhos diferentes, com três deles começando com anticoagulantes orais desde o início do quadro agudo de TVP e EP (rivaroxabana e edoxabana). Os outros três iniciaram com enoxaparina e varfarina durante os primeiros dias e depois seguiram com a medicação do grupo em avaliação (dabigatrana e apixabana). Resultados: Nos estudos analisados, todos obtiveram uma redução (valor de p de não inferioridade) dos eventos de recorrência de TEV com relação à varfarina. Nos desfechos de segurança, definidos como sangramento fatal, clinicamente relevante e outros, os novos anticoagulantes orais obtiveram uma diminuição significativa. Conclusões: Os anticoagulantes orais diretos tiveram redução da recorrência de eventos tromboembólicos (periférico e pulmonar), com redução significativa dos índices de sangramentos fatais ou não. A segurança coloca-os como opção segura e eficaz para o tratamento desses pacientes com risco baixo e intermediário de TEV

Introduction: Venous thromboembolism (VTE), including pulmonary embolism (PE) and deep vein thrombosis (DVT), is the third leading cause of death worldwide. The diagnosis is still underestimated in emergencies. The triggering factors are well defined, which assists in the stratification of risk and in the diagnosis of VTE, whether provoked or not, and will greatly influence the treatment time. Increased right ventricle and biological markers have played a large role in the prognosis. The clinical features are well defined, and there are various tools for diagnosis and for risk stratification, such as the Wells and Geneva criteria, among others. Complementary exams are now well defined, with pulmonary angiography being the gold standard, but with improved technology and high sensitivity and specificity, computerized angiotomography has played a prominent role. Other exams are still important in certain situations, such as D-dimer and other biomarkers, chest radiography, perfusion/ventilation scintigraphy, electrocardiogram, echocardiography, and lower limb venous Doppler. Method: In this article we review basic aspects of epidemiology, diagnosis, and risk stratification. The main focus was treatment with anticoagulant therapy, under which we reviewed the six clinical studies described between 2009 and 2013 that address the new oral anticoagulants, now called direct oral anticoagulants. These studies have different designs; three of them start with oral anticoagulants from the onset of acute DVT and PE (rivaroxaban and edoxaban), and the other three start with enoxaparin and warfarin during the first days and then with the medication of the study group being evaluated (dabigatran and apixaban). Results: In the analyzed studies, all of them obtained a reduction (non-inferiority p-value) of the events of VTE recurrence in relation to warfarin. In the safety outcomes, defined as clinically relevant fatal bleeding and others, the new oral anticoagulants achieved a significant reduction. Conclusions: Direct oral anticoagulants had a reduction in the recurrence of thromboembolic events (peripheral and pulmonary), with a significant reduction in rates of fatal or non-fatal bleeding. Their safety makes them a reliable and effective option for the treatment of these patients, with low and intermediate risk of VTE

Rivaroxaban or Aspirin for Extended Treatment of Venous Thromboembolism.

BACKGROUND: Although many patients with venous thromboembolism require extended treatment, it is uncertain whether it is better to use full- or lower-intensity anticoagulation therapy or aspirin. METHODS: In this randomized, double-blind, phase 3 study, we assigned 3396 patients with venous thromboembolism to receive either once-daily rivaroxaban (at doses of 20 mg or 10 mg) or 100 mg of aspirin. All the study patients had completed 6 to 12 months of anticoagulation therapy and were in equipoise regarding the need for continued anticoagulation. Study drugs were administered for up to 12 months. The primary efficacy outcome was symptomatic recurrent fatal or nonfatal venous thromboembolism, and the principal safety outcome was major bleeding. RESULTS: A total of 3365 patients were included in the intention-to-treat analyses (median treatment duration, 351 days). The primary efficacy outcome occurred in 17 of 1107 patients (1.5%) receiving 20 mg of rivaroxaban and in 13 of 1127 patients (1.2%) receiving 10 mg of rivaroxaban, as compared with 50 of 1131 patients (4.4%) receiving aspirin (hazard ratio for 20 mg of rivaroxaban vs. aspirin, 0.34; 95% confidence interval [CI], 0.20 to 0.59; hazard ratio for 10 mg of rivaroxaban vs. aspirin, 0.26; 95% CI, 0.14 to 0.47; P<0.001 for both comparisons). Rates of major bleeding were 0.5% in the group receiving 20 mg of rivaroxaban, 0.4% in the group receiving 10 mg of rivaroxaban, and 0.3% in the aspirin group; the rates of clinically relevant nonmajor bleeding were 2.7%, 2.0%, and 1.8%, respectively. The incidence of adverse events was similar in all three groups. CONCLUSIONS: Among patients with venous thromboembolism in equipoise for continued anticoagulation, the risk of a recurrent event was significantly lower with rivaroxaban at either a treatment dose (20 mg) or a prophylactic dose (10 mg) than with aspirin, without a significant increase in bleeding rates. (Funded by Bayer Pharmaceuticals; EINSTEIN CHOICE ClinicalTrials.gov number, NCT02064439 .).

Treatment of Venous Thromboembolism With New Anticoagulant Agents.

Venous thromboembolism (VTE) is a common disease associated with high risk for recurrences, death, and late sequelae, accounting for substantial health care costs. Anticoagulant agents are the mainstay of treatment for deep vein thrombosis and pulmonary embolism. The recent availability of oral anticoagulant agents that can be administered in fixed doses, without laboratory monitoring and dose adjustment, is a landmark change in the treatment of VTE. In Phase III trials, rivaroxaban, apixaban, edoxaban (antifactor Xa agents), and dabigatran (an antithrombin agent) were noninferior and probably safer than conventional anticoagulation therapy (low-molecular-weight heparin followed by vitamin K antagonists). These favorable results were confirmed in specific patient subgroups, such as the elderly and fragile. However, some patients, such as those with cancer or with intermediate- to high-risk pulmonary embolism, were underrepresented in the Phase III trials. Further clinical research is required before new oral anticoagulant agents can be considered standard of care for the full spectrum of patients with VTE.

Risk of thromboembolism, recurrent hemorrhage, and death after warfarin therapy interruption for intracranial hemorrhage.

BACKGROUND: Whether and when to resume oral anticoagulant therapy for patients who survive warfarin-related intracranial hemorrhage (ICH) remains a dilemma lacking consensus recommendations and high-quality evidence to guide clinical decision making. OBJECTIVE: To determine the incidences of recurrent ICH, thrombosis, and death in relation to resumption or non-resumption of warfarin therapy during the 365 days after incident ICH. METHODS: We conducted a retrospective cohort study of adult patients in an integrated healthcare delivery system who were receiving warfarin therapy at the time of incident (index) ICH between 1/1/2000 and 12/31/2007 and survived to hospital discharge. The primary outcomes were recurrent ICH, thrombosis (stroke, systemic embolism, and venous thromboembolism), and all-cause mortality during the 365 days following index ICH. Patients were assigned to one of two groups defined by warfarin therapy resumption after the index ICH. RESULTS: There were 160 patients discharged from the hospital following warfarin-related index ICH; of these 54 (33.8%) resumed warfarin therapy and 106 (66.2%) did not. Recurrent ICH occurred in a numerically greater, but statistically non-significant, proportion of patients who did not resume warfarin therapy (7.6% vs. 3.7%, p=0.497). Similarly, patients who did not resume warfarin had a three-fold higher (12.3% vs. 3.7%, p=0.092) and approximately two-fold higher (31.1% vs. 18.5%, p=0.089) rates of thrombosis and all-cause mortality, respectively, during follow up. CONCLUSION: Resumption of warfarin therapy following warfarin-associated ICH appeared not to be associated with increased risk of recurrent ICH but trended toward reduced thrombosis and all-cause mortality.

The cost-utility of dabigatran etexilate compared with warfarin in treatment and extended anticoagulation of acute VTE in the UK.

The relative efficacy and safety of dabigatran etexilate and warfarin have been evaluated in two head-to-head, phase III, treatment of acute venous thromboembolism (VTE) trials, and one extended prophylaxis trial, in patients with high risk of recurrent VTE. Dabigatran etexilate demonstrated similar efficacy to warfarin, and was associated with a reduced risk of major or clinically relevant bleeds. Based on results of these trials, and real-life disease prognosis following discontinuation of anticoagulation treatment, we evaluated the cost-utility of dabigatran etexilate compared with warfarin in six months anticoagulation, and in extended, up to 24 months anticoagulation, in patients with acute VTE, acute deep-vein thrombosis (DVT) or acute, symptomatic, pulmonary embolism (PE). Costs were analysed from the perspective of the National Health Services (NHS) and Public Social Services (PSS) in England and Wales. Outcomes were quantified in quality-adjusted life years (QALY). The estimated incremental, lifetime cost/QALY gain following acute, symptomatic VTE (DVT or PE) was £1,252/QALY when dabigatran etexilate or warfarin were administered for up to six months treatment. In treatment of acute, symptomatic PE and in DVT respective ratios were £1,767/QALY and £1,075/QALY. In extended, up to 24 months anticoagulation, dabigatran etexilate projected costs/QALY of £8,242/QALY, when compared with warfarin. Results obtained herein were robust across a number of sensitivity analyses and suggest dabigatran etexilate to be a cost-effective alternative to current standard of care when evaluated in six months treatment and in extended anticoagulation following acute VTE (DVT and/or PE).

Meta-analysis on efficacy and safety of new oral anticoagulants for venous thromboembolism prophylaxis in elderly elective postarthroplasty patients.

The risk of venous thromboembolism (VTE) increases with age. New oral anticoagulants (NOACs) have been increasingly studied for VTE prophylaxis in patients with elective postarthroplasty. Although the elderly population accounts for a significant proportion of patients requiring VTE prophylaxis, safety and efficacy of NOACs in this subgroup for VTE prophylaxis has not been well studied. Relevant studies were identified through electronic literature searches of MEDLINE, EMBASE, Cochrane Library, and ClinicalTrials.gov (from inception to 12 August 2014). Phase III randomized controlled trials that compared NOACs against low-molecular-weight heparin (LMWH) in the prevention of VTE prophylaxis in patients with elective postarthroplasty were included. We defined our elderly population as adults of at least 75 years and assessed the reported safety and efficacy outcomes with NOACs in this population. Study-specific odds ratios (ORs) were calculated and between-study heterogeneity was assessed using the I statistic. In nine trials involving 29 403 patients, the risk of VTE or VTE-related deaths in elderly patients with elective postarthroplasty was similar with NOACs compared with LMWH (OR 0.62, 95% confidence interval 0.30-1.26; P = 0.18; I = 44%) but bleeding risk was significantly lower (OR 0.71, 95% confidence interval 0.53-0.94; P = 0.02; I = 0%). Analysis of individual NOACs showed superior efficacy but similar safety for apixaban when compared with LMWH. Efficacy and safety profiles of rivaroxaban and dabigatran were similar to LMWH. In elderly patients with elective postarthroplasty, NOACs have similar efficacy but superior safety when compared with enoxaparin for VTE prophylaxis.

Rivaroxaban versus high dose nadroparin for thromboprophylaxis after hip or knee arthroplasty.

UNLABELLED: Deep-vein thrombosis and subsequent pulmonary embolism are major complications in total joint arthroplasty of the lower limbs. New oral anticoagulants are increasingly prescribed as thromboprophylaxis due to their simple administration and encouraging phase III marketing studies. PATIENTS, METHODS: In this observational study, we compared the efficacy and safety of rivaroxaban with nadroparin in 1302 unselected patients receiving hip or knee arthroplasty. RESULTS: Venous thrombembolism occurred in 3.3% (2.3%; 4.7%, 95% CI, n = 838) of patients receiving rivaroxaban and in 4.3% (2.7%; 6.7%, 95% CI, n = 464) of patients receiving nadroparin resulting in an absolute risk reduction (ARR) of 1.0% (-1.4%; 3.3%, 95% CI). CONCLUSIONS: With an odds ratio of 0.6 (0.4; 1.0, 95% CI), rivaroxaban was associated with a decreased perioperative drop in haemoglobin exhibiting an improved thromboprophylactic profile when compared to high dose nadroparin. Furthermore, transfusion rates were 8.8% (-2.7%; 19.9%, 95% CI) lower in patients receiving rivaroxaban. However, as previous studies have shown, low preoperative haemoglobin remains the most predictive factor for postoperative transfusions (OR: 2.4 [1.3; 4.4, 95% CI]).