Oral rivaroxaban for symptomatic venous thromboembolism

Emulation of Randomized Clinical Trials With Nonrandomized Database Analyses: Results of 32 Clinical Trials

Importance

Nonrandomized studies using insurance claims databases can be analyzed to produce real-world evidence on the effectiveness of medical products. Given the lack of baseline randomization and measurement issues, concerns exist about whether such studies produce unbiased treatment effect estimates.

Objective

To emulate the design of 30 completed and 2 ongoing randomized clinical trials (RCTs) of medications with database studies using observational analogues of the RCT design parameters (population, intervention, comparator, outcome, time [PICOT]) and to quantify agreement in RCT-database study pairs.

Design, Setting, and Participants

New-user cohort studies with propensity score matching using 3 US claims databases (Optum Clinformatics, MarketScan, and Medicare). Inclusion-exclusion criteria for each database study were prespecified to emulate the corresponding RCT. RCTs were explicitly selected based on feasibility, including power, key confounders, and end points more likely to be emulated with real-world data. All 32 protocols were registered on ClinicalTrials.gov before conducting analyses. Emulations were conducted from 2017 through 2022.

Exposures

Therapies for multiple clinical conditions were included.

Main Outcomes and Measures

Database study emulations focused on the primary outcome of the corresponding RCT. Findings of database studies were compared with RCTs using predefined metrics, including Pearson correlation coefficients and binary metrics based on statistical significance agreement, estimate agreement, and standardized difference.

Results

In these highly selected RCTs, the overall observed agreement between the RCT and the database emulation results was a Pearson correlation of 0.82 (95% CI, 0.64-0.91), with 75% meeting statistical significance, 66% estimate agreement, and 75% standardized difference agreement. In a post hoc analysis limited to 16 RCTs with closer emulation of trial design and measurements, concordance was higher (Pearson r, 0.93; 95% CI, 0.79-0.97; 94% meeting statistical significance, 88% estimate agreement, 88% standardized difference agreement). Weaker concordance occurred among 16 RCTs for which close emulation of certain design elements that define the research question (PICOT) with data from insurance claims was not possible (Pearson r, 0.53; 95% CI, 0.00-0.83; 56% meeting statistical significance, 50% estimate agreement, 69% standardized difference agreement).

Conclusions and Relevance

Real-world evidence studies can reach similar conclusions as RCTs when design and measurements can be closely emulated, but this may be difficult to achieve. Concordance in results varied depending on the agreement metric. Emulation differences, chance, and residual confounding can contribute to divergence in results and are difficult to disentangle.

Direct-acting oral anticoagulants in antiphospholipid syndrome: A systematic review

The objective of the systematic review is to analyze the efficacy of direct-acting oral anticoagulants (DOAC) in the prophylaxis of thrombosis in antiphospholipid syndrome (APS). We searched for clinical trials, cohort studies and meta-analyses published from January 1, 2012 to September 30, 2022. Articles that analyzed the efficacy of DOAC in the prevention of thrombosis recurrence, with or without comparison with antivitamin K (VKA) drugs, were selected. DOACs, specifically rivaroxaban and apixaban, were significantly less effective than VKAs in preventing recurrence of thrombosis in patients with APS and prior arterial thrombosis or the concomitant presence of two or three different antiphospholipid antibodies. The proportion of patients with severe bleeding as side effect are similar in those treated with DOAC and with VKA. The results argue against the use of DOAC in the treatment of patients with thrombotic APS.

Oral direct thrombin inhibitors or oral factor Xa inhibitors versus conventional anticoagulants for the treatment of deep vein thrombosis

BACKGROUND

Deep vein thrombosis (DVT) is a condition in which a clot forms in the deep veins, most commonly of the leg. It occurs in approximately one in 1000 people. If left untreated, the clot can travel up to the lungs and cause a potentially life-threatening pulmonary embolism (PE). Previously, a DVT was treated with the anticoagulants heparin and vitamin K antagonists. However, two forms of direct oral anticoagulants (DOACs) have been developed: oral direct thrombin inhibitors (DTIs) and oral factor Xa inhibitors, which have characteristics that may be favourable compared to conventional treatment, including oral administration, a predictable effect, lack of frequent monitoring or dose adjustment and few known drug interactions. DOACs are now commonly being used for treating DVT: recent guidelines recommended DOACs over conventional anticoagulants for both DVT and PE treatment. This Cochrane Review was first published in 2015. It was the first systematic review to measure the effectiveness and safety of these drugs in the treatment of DVT. This is an update of the 2015 review.  OBJECTIVES: To assess the effectiveness and safety of oral DTIs and oral factor Xa inhibitors versus conventional anticoagulants for the long-term treatment of DVT.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase and CINAHL databases and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 1 March 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) in which people with a DVT, confirmed by standard imaging techniques, were allocated to receive an oral DTI or an oral factor Xa inhibitor compared with conventional anticoagulation or compared with each other for the treatment of DVT.  DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcomes were recurrent venous thromboembolism (VTE), recurrent DVT and PE. Secondary outcomes included all-cause mortality, major bleeding, post-thrombotic syndrome (PTS) and quality of life (QoL). We used GRADE to assess the certainty of evidence for each outcome.

MAIN RESULTS

We identified 10 new studies with 2950 participants for this update. In total, we included 21 RCTs involving 30,895 participants. Three studies investigated oral DTIs (two dabigatran and one ximelagatran), 17 investigated oral factor Xa inhibitors (eight rivaroxaban, five apixaban and four edoxaban) and one three-arm trial investigated both a DTI (dabigatran) and factor Xa inhibitor (rivaroxaban). Overall, the studies were of good methodological quality. Meta-analysis comparing DTIs to conventional anticoagulation showed no clear difference in the rate of recurrent VTE (odds ratio (OR) 1.17, 95% confidence interval (CI) 0.83 to 1.65; 3 studies, 5994 participants; moderate-certainty evidence), recurrent DVT (OR 1.11, 95% CI 0.74 to 1.66; 3 studies, 5994 participants; moderate-certainty evidence), fatal PE (OR 1.32, 95% CI 0.29 to 6.02; 3 studies, 5994 participants; moderate-certainty evidence), non-fatal PE (OR 1.29, 95% CI 0.64 to 2.59; 3 studies, 5994 participants; moderate-certainty evidence) or all-cause mortality (OR 0.66, 95% CI 0.41 to 1.08; 1 study, 2489 participants; moderate-certainty evidence). DTIs reduced the rate of major bleeding (OR 0.58, 95% CI 0.38 to 0.89; 3 studies, 5994 participants; high-certainty evidence).   For oral factor Xa inhibitors compared with conventional anticoagulation, meta-analysis demonstrated no clear difference in recurrent VTE (OR 0.85, 95% CI 0.71 to 1.01; 13 studies, 17,505 participants; moderate-certainty evidence), recurrent DVT (OR 0.70, 95% CI 0.49 to 1.01; 9 studies, 16,439 participants; moderate-certainty evidence), fatal PE (OR 1.18, 95% CI 0.69 to 2.02; 6 studies, 15,082 participants; moderate-certainty evidence), non-fatal PE (OR 0.93, 95% CI 0.68 to 1.27; 7 studies, 15,166 participants; moderate-certainty evidence) or all-cause mortality (OR 0.87, 95% CI 0.67 to 1.14; 9 studies, 10,770 participants; moderate-certainty evidence). Meta-analysis showed a reduced rate of major bleeding with oral factor Xa inhibitors compared with conventional anticoagulation (OR 0.63, 95% CI 0.45 to 0.89; 17 studies, 18,066 participants; high-certainty evidence).  AUTHORS' CONCLUSIONS: The current review suggests that DOACs may be superior to conventional therapy in terms of safety (major bleeding), and are probably equivalent in terms of efficacy. There is probably little or no difference between DOACs and conventional anticoagulation in the prevention of recurrent VTE, recurrent DVT, pulmonary embolism and all-cause mortality. DOACs reduced the rate of major bleeding compared to conventional anticoagulation. The certainty of evidence was moderate or high.

Duration of Initial Intensive Rivaroxaban Therapy for Patients With Venous Thromboembolism - Subanalysis of the J'xactly Study

Background: Rivaroxaban, a direct oral anticoagulant, is used as a first-line treatment to prevent venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE). However, whether 21 days is optimal for the initial treatment duration has not been investigated. Methods and Results: In this subanalysis of the prospective multicenter observational J'xactly study, which included 1,039 Japanese patients with acute symptomatic/asymptomatic DVT/PE who were prescribed rivaroxaban, the VTE recurrence rate and incidence of bleeding complications were assessed in 667 patients who underwent intensive rivaroxaban treatment (15 mg, twice daily) for a short (1-8 days), intermediate (9-16), or standard (17-24) duration. The short treatment duration group showed a tendency for increased VTE recurrence/aggravation compared with the standard treatment duration group (6.10% vs. 2.60% per patient-year). The intermediate treatment duration group showed a higher incidence of bleeding events than the standard treatment duration group (9.34% vs. 2.16% per patient-year), without major differences in patient characteristics between the groups. Conclusions: In this subanalysis of the real-world observational J'xactly study of VTE treatment and prevention in Japanese patients with acute symptomatic/asymptomatic DVT/PE, the standard initial intensive rivaroxaban treatment duration (17-24 days) appeared to be safe and effective, providing important insights into the clinical outcomes of the initial rivaroxaban treatment duration in this population.

Epidemiology and prevention of venous thromboembolism

Venous thromboembolism, that consists of the interrelated conditions deep-vein thrombosis and pulmonary embolism, is an under-appreciated vascular disease. In Western regions, approximately 1 in 12 individuals will be diagnosed with venous thromboembolism in their lifetime. Rates of venous thromboembolism are lower in Asia, but data from other regions are sparse. Numerous risk factors for venous thromboembolism have been identified, which can be classified as acute or subacute triggers (provoking factors that increase the risk of venous thromboembolism) and basal or acquired risk factors (which can be modifiable or static). Approximately 20% of individuals who have a venous thromboembolism event die within 1 year (although often from the provoking condition), and complications are common among survivors. Fortunately, opportunities exist for primordial prevention (prevention of the development of underlying risk factors), primary prevention (management of risk factors among individuals at high risk of the condition) and secondary prevention (prevention of recurrent events) of venous thromboembolism. In this Review, we describe the epidemiology of venous thromboembolism, including the incidence, risk factors, outcomes and opportunities for prevention. Meaningful health disparities exist in both the incidence and outcomes of venous thromboembolism. We also discuss these disparities as well as opportunities to reduce them.

Clinical Studies with Anticoagulants that Have Changed Clinical Practice

Anticoagulant therapy is the cornerstone of treatment and prevention of arterial and venous thromboembolism. Taking a historical perspective, starting in the 1960s, and progressing through to 2022, we discuss key clinical trials of anticoagulants that have changed clinical practice, and examine obstacles encountered in bringing these anticoagulants to the clinic. The design of some of the early studies that shaped clinical practice was poor by current standards, but their results were influential because nothing better was available. Both heparin and vitamin K antagonists had been in clinical use for several decades before well-designed trials in the 1980s optimized their dosing and enhanced their safety and efficacy. Low-molecular-weight heparin then replaced unfractionated heparin because it had a more predictable dose-response and a longer half-life, thereby allowing it to be used conveniently in out-of-hospital settings. More recently, direct oral anticoagulants became the oral anticoagulants of choice for most indications because they were shown to be at least as safe and effective as vitamin K antagonists when used in fixed doses without the need for laboratory monitoring. The design of the trials that led to the approval of the direct oral anticoagulants was excellent, but further studies are required to optimize their dosing in selected patients who were underrepresented in these trials.

Pharmacist Practice Patterns Regarding Direct Oral Anticoagulants for Treatment of Venous Thromboembolism

Background: Direct oral anticoagulants (DOACs) are increasingly prescribed for the treatment of venous thromboembolism (VTE). However, little is known regarding pharmacists' practice patterns and preferences in clinical areas of contention, such as initiation dosing, obesity, and renal impairment. Objective: To determine pharmacist trends in practice regarding DOACs for the treatment of VTE overall and within areas of clinical controversy. Methods: An electronic survey was distributed to pharmacists in the United States through national and state pharmacy organizations. Responses were collected for 30 days. Results: One hundred fifty-three complete responses were submitted. The majority of pharmacists preferred apixaban (90.2%) for the oral treatment of venous thromboembolism. When initiating apixaban or rivaroxaban for a new VTE, 76% and 64% of pharmacists surveyed, respectively, state the duration of the initiation dose phases are reduced if the patient received parenteral anticoagulation. Fifty-eight percent of pharmacists used body mass index to evaluate the appropriateness of DOACs in obese patients whereas 42% used total body weight. Preference for rivaroxaban (31.4%) was higher in this population compared to the global population (10%). Apixaban was preferred for patients with renal impairment (92.2%). However, as creatinine clearance as calculated by the Cockcroft-Gault equation (CrCl) reduced to ≤15 milliliters/minute (mL/min), preference for warfarin increased (36%). Conclusion: This national survey of pharmacists demonstrated an overall preference for apixaban and significant variability in practice patterns regarding DOACs for patients with new VTE, patients with obesity, and patients with renal impairment. Further research is warranted to evaluate the efficacy and safety of DOAC initiation dosing phase modifications. Prospective evaluations of DOACs in obese and renal dysfunction populations would confirm the safety and efficacy of DOACs in these populations.

Outcome of Budd-Chiari Syndrome Patients Treated With Direct Oral Anticoagulants: An Austrian Multicenter Study

BACKGROUND AND AIMS

Direct oral anticoagulants (DOACs) may simplify management of Budd-Chiari syndrome (BCS). Here, we report our experience with off-label use of DOACs for anticoagulation in BCS.

METHODS

The safety of DOAC vs vitamin K antagonist treatment as well as associated clinical outcomes were retrospectively assessed in 47 BCS patients treated at 6 Austrian centers.

RESULTS

Mean age at study inclusion was 37.9 ± 14.0 years and mean Model for End-Stage Liver Disease was 13.1 ± 5.1. Overall, 63.8% (n = 30) of patients had decompensated liver disease, and 87.2% (n = 41) showed clinical signs of portal hypertension. During a median follow-up of 82.5 (interquartile range, 43.1-121.8) months, 43 (91.5%) patients received anticoagulation alone or following interventional treatment, including 22 (46.8%) patients treated with DOACs (edoxaban: 10, apixaban: 4, rivaroxaban: 3, dabigatran: 3, more than one DOAC sequentially: 2) for a median of 24.4 (interquartile range, 5.7-35.1) months. While 72.7% (n = 16 of 22) of patients were switched from low-molecular-weight heparin (n = 12) or vitamin K antagonist (n = 4) to DOAC after disease stabilization or improvement, 27.3% (n = 6 of 22) of BCS patients were initially treated with DOAC. Complete response (European Association for the Study of the Liver criteria) was achieved or maintained in 14 (63.6%) of 22 patients, with ongoing response in 2 patients, while disease progressed in 6 patients (including 2 patients with hepatocellular carcinoma). Four major spontaneous bleedings (18.2%; incidence rate 8.8 per 100 patient-years; n = 2 upper gastrointestinal bleeding, n = 1 lower gastrointestinal bleeding, n = 1 hepatocellular carcinoma rupture), 7 minor bleedings, and 1 major procedure-related bleeding (4.5%; 2.2 per 100 patient-years) occurred during DOAC therapy. Overall transplant-free survival was 91.6% at 5 years.

CONCLUSIONS

DOACs seem to be effective and safe for long-term anticoagulation in patients with BCS, but confirmation by larger prospective studies is needed.

Management of acute pulmonary embolism with sequential hybrid therapy of surgical thrombectomy and rivaroxaban intensive therapy: a case report

Acute pulmonary embolism (PE) is often associated with rapid hemodynamic deterioration or death. Therefore, early therapeutic intervention is important. A 45-year-old man was diagnosed with intermediate-high risk PE, and sequential hybrid therapy consisting of surgical thrombectomy and rivaroxaban intensive therapy was administered. During the course of treatment, echocardiography revealed improvement in pulmonary artery systolic pressure, and thrombus volume analysis by computed tomography revealed a drastic reduction in the size of the thrombus. Sequential hybrid therapy for acute PE not only stabilizes hemodynamics, but may also prevent conversion to chronic thromboembolic pulmonary hypertension by sufficiently reducing the volume of the thrombus.

Pulmonary Thromboembolism Developed During Hospitalization: A Nationwide Retrospective Observational Study Using Claims Data

INTRODUCTION

Evidence regarding the development of pulmonary thromboembolism (PE) during hospitalization is unclear. We hypothesized that the incidence of PE could vary depending on clinical department and aimed to conduct a survey on the incidence of in-hospital PE.

METHODS

We conducted a retrospective analysis using claims data of in-hospital patients in Japan. We collected background information regarding patients with and without PE occurrence during hospitalization. Further, we determined the incidence of PE and implemented prophylactic procedures in patients with and without surgery according to clinical department at admission. Finally, we examined the duration of hospital stay and in-hospital mortality rates in patients with and without PE.

RESULTS

We found that 5007 (0.107%, 20.61 per 1000 person-years) patients developed PE during hospitalization and differed by clinical department at admission. Moreover, 2272 (0.095%, 19.3 per 1000 person-years) and 2735 (0.119%, 21.8 per 1000 person-years) patients with and without surgery, respectively, developed PE during hospitalization (P < 0.001). Further, 33.8% of inpatients underwent prophylactic procedures for PE; however, the implementation rate differed between patients with and without surgery (59.2% vs. 7.3%, P < 0.001). The median duration of hospital stay in patients with and without PE was 31.0 and 11.0 days, and the in-hospital mortality rates in patients with and without PE were 11.0% and 3.5%, respectively (P < 0.001).

DISCUSSION

The incidence of in-hospital PE differed according to patient characteristics, clinical departments, and presence/absence of surgery. The onset of PE during hospitalization leads to prolonged hospital stay and in-hospital death.

CONCLUSION

It is important to conduct a proper risk assessment on admission as well as to implement proper prophylactic procedures to prevent the development of PE during hospitalization.

Emergent external ventricular drain placement in patients with factor Xa inhibitor-associated intracerebral hemorrhage after reversal with andexanet alfa

BACKGROUND

Andexanet alfa (AA), a factor Xa-inhibitor (FXi) reversal agent, is given as a bolus followed by a 2-hour infusion. This long administration time can delay EVD placement in intracerebral hemorrhage (ICH) patients. We sought to evaluate the safety of EVD placement immediately post-AA bolus compared to post-AA infusion.

METHODS

We conducted a retrospective study that included adult patients admitted with FXi-associated ICH who received AA and underwent EVD placement The primary outcome was the occurrence of a new hemorrhage (tract, extra-axial, or intraventricular hemorrhage). Secondary outcomes included mortality, intensive care unit and hospital length of stay, and discharge modified Rankin Score. The primary safety outcome was documented thrombotic events.

RESULTS

Twelve patients with FXi related ICH were included (EVD placement post-AA bolus, N = 8; EVD placement post-AA infusion, N = 4). Each arm included one patient with bilateral EVD placed. There was no difference in the incidence of new hemorrhages, with one post-AA bolus patient had small, focal, nonoperative extra-axial hemorrhage. Morbidity and mortality were higher in post-AA infusion patients (mRS, post-AA bolus, 4 [4-6] vs. post-AA infusion 6 [5,6], p = 0.24 and post-AA bolus, 3 (37.5 %) vs. post-AA infusion, 3 (75 %), p = 0.54, respectively). One patient in the post-AA bolus group had thrombotic event. There was no difference in hospital LOS (post-AA bolus, 19 days [12-26] vs. post-AA infusion, 14 days [9-22], p = 0.55) and ICU LOS (post-AA bolus, 10 days [6-13] vs. post-AA infusion, 11 days [5-21], p = 0.86).

CONCLUSION

We report no differences in the incidence of tract hemorrhage, extra-axial hemorrhage, or intraventricular hemorrhage post-AA bolus versus post-AA infusion. Larger prospective studies to validate these results are warranted.

Personalizing Direct Oral Anticoagulant Therapy for a Diverse Population: Role of Race, Kidney Function, Drug Interactions, and Pharmacogenetics

Oral anticoagulants (OACs) are commonly used to reduce the risk of venous thromboembolism and the risk of stroke in patients with atrial fibrillation. Endorsed by the American Heart Association, American College of Cardiology, and the European Society of Cardiology, direct oral anticoagulants (DOACs) have displaced warfarin as the OAC of choice for both conditions, due to improved safety profiles, fewer drug-drug and drug-diet interactions, and lack of monitoring requirements. Despite their widespread use and improved safety over warfarin, DOAC-related bleeding remains a major concern for patients. DOACs have stable pharmacokinetics and pharmacodynamics; however, variability in DOAC response is common and may be attributed to numerous factors, including patient-specific factors, concomitant medications, comorbid conditions, and genetics. Although DOAC randomized controlled trials included patients of varying ages and levels of kidney function, they failed to include patients of diverse ancestries. Additionally, current evidence to support DOAC pharmacogenetic associations have primarily been derived from European and Asian individuals. Given differences in genotype frequencies and disease burden among patients of different biogeographic groups, future research must engage diverse populations to assess and quantify the impact of predictors on DOAC response. Current under-representation of patients from diverse racial groups does not allow for proper generalization of the influence of clinical and genetic factors in relation to DOAC variability. Herein, we discuss factors affecting DOAC response, such as age, sex, weight, kidney function, drug interactions, and pharmacogenetics, while offering a new perspective on the need for further research including frequently excluded groups.

The Challenge of Intermediate-Risk Pulmonary Embolism

BACKGROUND

Intermediate-risk pulmonary embolism is a common disease that is associated with significant morbidity and mortality; however, a standardized treatment protocol is not well-established.

AREAS OF UNCERTAINTY

Treatments available for intermediate-risk pulmonary embolisms include anticoagulation, systemic thrombolytics, catheter-directed therapies, surgical embolectomy, and extracorporeal membrane oxygenation. Despite these options, there is no clear consensus on the optimal indication and timing of these interventions.

THERAPEUTIC ADVANCES

Anticoagulation remains the cornerstone of treatment for pulmonary embolism; however, over the past 2 decades, there have been advances in the safety and efficacy of catheter-directed therapies. For massive pulmonary embolism, systemic thrombolytics and, sometimes, surgical thrombectomy are considered first-line treatments. Patients with intermediate-risk pulmonary embolism are at high risk of clinical deterioration; however, it is unclear whether anticoagulation alone is sufficient. The optimal treatment of intermediate-risk pulmonary embolism in the setting of hemodynamic stability with right heart strain present is not well-defined. Therapies such as catheter-directed thrombolysis and suction thrombectomy are being investigated given their potential to offload right ventricular strain. Several studies have recently evaluated catheter-directed thrombolysis and embolectomies and demonstrated the efficacy and safety of these interventions. Here, we review the literature on the management of intermediate-risk pulmonary embolisms and the evidence behind those interventions.

CONCLUSIONS

There are many treatments available in the management of intermediate-risk pulmonary embolism. Although the current literature does not favor 1 treatment as superior, multiple studies have shown growing data to support catheter-directed therapies as potential options for these patients. Multidisciplinary pulmonary embolism response teams remain a key feature in improving the selection of advanced therapies and optimization of care.

Effectiveness and safety of rivaroxaban in patients with venous thromboembolism and active cancer: A subanalysis of the J'xactly study

BACKGROUND

Data on the effectiveness and safety of rivaroxaban for the treatment of patients with venous thromboembolism (VTE) and active cancer are limited in the Japanese real-world setting.

METHODS

In this subanalysis of the J'xactly study, which was a multicenter, prospective, observational study, we evaluated the effectiveness and safety of rivaroxaban in patients with acute VTE and active cancer (n = 193) versus those without active cancer (n = 823).

RESULTS

Compared with patients without active cancer, those with active cancer demonstrated a significantly different age distribution, with fewer aged <65 and ≥75 years; a lower proportion of women; a lower mean body mass index; and a lower proportion of physical inactivity, injury, thrombophilia, and heart failure. There was no difference in the initial dose distribution of rivaroxaban between patients with and without active cancer. The incidences of recurrence or aggravation of symptomatic VTE and major bleeding were not significantly different [VTE: 1.44 % vs. 2.80 % per patient-year, hazard ratio (HR) 0.50, 95 % confidence interval (CI) 0.18-1.39, p = 0.172; major bleeding: 4.49 % vs. 2.55 % per patient-year, HR 1.80, 95 % CI 0.82-3.95, p = 0.137]. Approximately 10 % of patients with active cancer died at 6 months, with a significantly higher cumulative all-cause mortality rate than those without active cancer (23.29 % vs. 2.03 % per patient-year, HR 11.31, 95 % CI 7.30-17.53, p < 0.001).

CONCLUSIONS

In patients with VTE and active cancer, rivaroxaban showed acceptable effectiveness, although clinically significant bleeding remains a concern.

CLINICAL TRIAL REGISTRATION

UMIN Clinical Trials Registry number, UMIN000025072.

Trends in the Use of Oral Anticoagulants for Adults With Venous Thromboembolism in the US, 2010-2020

Importance

The introduction of direct oral anticoagulants (DOACs) has transformed the treatment of venous thromboembolism (VTE). Large health care databases offer valuable insight into how oral anticoagulants (OACs) are used in clinical practice and may aid in understanding reasons for changes in therapy.

Objectives

To evaluate prescribing patterns of OACs for patients with VTE and identify clinical events that precede treatment changes.

Design, Setting, and Participants

This retrospective cohort study used data from a public (Medicare fee-for-service) and a commercial (IBM MarketScan) health insurance database on 298 609 patients initiating OACs within 90 days of index VTE hospitalization from January 1, 2009, to December 31, 2020. Statistical analysis was conducted from April to August 2022.

Exposures

Warfarin and the DOACs rivaroxaban, apixaban, dabigatran, and edoxaban.

Main Outcomes and Measures

Characteristics of patients initiating different OACs, along with trends over time of patients initiating OACs, were compared. Time receiving continuous anticoagulant therapy, patterns of anticoagulant discontinuation (treatment gap of ≥30 days), and treatment switches were assessed. Clinical events in the 30 days preceding treatment modifications were identified.

Results

A total of 203 378 individuals with Medicare (mean [SD] age, 76.9 [7.6] years; 122 554 women [60.3%]) and 95 231 with commercial insurance (mean [SD] age, 57.6 [15.8] years; 47 139 women [49.5%]) were included (N = 298 609). Warfarin was the most frequent OAC prescribed (163 044 [54.6%]), followed by rivaroxaban (66 882 [22.3%]) and apixaban (65 997 [22.1%]). The proportion of patients initiating DOACs increased from 0% in 2010 to 86.8% (22 420 of 25 817) in 2019 for patients with Medicare and 92.1% (4012 of 4357) in 2020 for commercially insured patients. Patients with chronic kidney disease were more likely to initiate warfarin (35 561 [11.9%]) or apixaban (16 294 [5.5%]) than rivaroxaban (10 136 [3.4%]), and those with a history of bleeding were more likely to initiate apixaban (5424 [1.8%]) than rivaroxaban (3007 [1.0%]). Overall, patients received persistent OAC treatment for approximately 6 months (Medicare: median, 175 days [IQR, 76-327 days]; commercial insurance: median, 168 days [IQR, 83-279 days]). A total of 33 011 patients (11.1%) switched anticoagulant therapy within a year. Switching to another anticoagulant was preceded most frequently by codes for a VTE diagnostic procedure (27.2% of all switchers [8983 of 33 011]).

Conclusions and Relevance

This cohort study using data from 2 US health insurance databases suggests that most patients with VTE continued oral anticoagulant treatment for approximately 6 months. Clinical reasons for modifying anticoagulant therapy were identified in one-third of patients. Identifying reasons for treatment modification is crucial for generating valid evidence on drug safety and effectiveness.

Factor Xa inhibitors versus vitamin K antagonist in morbidly obese patients with venous thromboembolism: a systematic review and meta-analysis

INTRODUCTION

Guidelines have endorsed non-vitamin K antagonist oral anticoagulants (NOACs), consisting of factor Xa inhibitors (xabans) and direct thrombin inhibitors, as the first line of treatment in venous thromboembolism (VTE) and atrial fibrillation. However, morbidly obese patients were under-represented in landmark trials of NOACs. Therefore, this study aimed to systematically review and perform a meta-analysis of studies on xabans versus vitamin K antagonist (VKA) in this high-risk population with VTE.

METHODS

PubMed, Embase, Medline, Cochrane library, and Google Scholar databases were searched to identify studies that compared xabans and VKA in treating morbidly obese patients with VTE. Morbid obesity was defined as body weight ≥ 120 kg or BMI ≥ 40 kg/m². Outcomes of interest included recurrent VTE, major bleeding, and clinically relevant non-major bleeding (CRNMB).

RESULTS

Eight studies comprising 30,895 patients were included. A total of 12,755 patients received xabans while 18,140 received VKAs. No significant difference in the odds of recurrent VTE (OR 0.75, 95% CI 0.55-1.01) and CRNMB (OR 0.69, 95% CI 0.44-1.09) was observed between the xabans group and the VKA group. However, the xabans group was associated with lower odds of major bleeding (OR 0.70, 95% CI 0.59-0.83).

CONCLUSION

Xabans have lower odds of major bleeding but similar odds of recurrent VTE when compared with VKAs in treating VTE in morbidly obese patients. Large registry analyses or future randomized controlled trials will be helpful in confirming these findings.

Economic Evaluation of Direct Oral Anticoagulants Compared to Warfarin for Venous Thromboembolism in Thailand: A Cost-Utility Analysis

BACKGROUND

Direct oral anticoagulants (DOACs) have been used for venous thromboembolism (VTE) in Thailand. However, they have not been listed in the National List of Essential Medicines (NLEM). A cost-effectiveness analysis is needed to aid policymakers in deciding whether DOACs should be listed in the NLEM. This study aimed to assess the cost-effectiveness of DOACs for patients with VTE in Thailand.

METHODS

A cohort-based state transition model was constructed from a societal perspective with a lifetime horizon. All available DOACs, including apixaban, rivaroxaban, edoxaban, and dabigatran, were compared with warfarin. A 6-month cycle length was used to capture all costs and health outcomes. The model consisted of nine health states, including VTE on treatment, VTE off treatment, recurrent VTE, clinically relevant non-major bleeding, gastrointestinal bleeding, intracranial bleeding, post-intracranial bleeding, chronic thromboembolic pulmonary hypertension, and death. All inputs were based on a comprehensive literature review. The model outcomes included total cost and quality-adjusted life-years (QALYs) with a 3% annual discount rate. A fully incremental cost-effectiveness analysis and the incremental cost-effectiveness ratio (ICER) per QALY gained were calculated at a willingness-to-pay (WTP) of THB 160,000/QALY ($5003). The robustness of the findings was assessed using deterministic and probabilistic sensitivity analyses.

RESULTS

All DOACs were associated with a decreased risk of VTE recurrence and intracranial hemorrhage. In the base-case analysis, apixaban could increase 0.16 QALYs compared with warfarin. An ICER for apixaban was 269,809 Thai baht (THB)/QALY ($8437/QALY). Rivaroxaban had a better QALY than warfarin at 0.09 QALYs with an ICER of 757,363 THB/QALY ($23,682/QALY). Edoxaban and dabigatran could also increase by 0.10 QALYs with an ICER of 709,945 THB ($22,200) and 707,145 THB ($22,122)/QALY, respectively. Our probabilistic sensitivity analyses indicated that warfarin had a 99.8% possibility of being cost-effective, while apixaban had a 0.2% possibility of being cost-effective at the current WTP. Other DOACs had no possibility of being cost-effective.

CONCLUSIONS

All DOACs were not cost-effective for VTE treatment at the current WTP in Thailand. Apixaban is likely to be the best option among DOACs.

Precautions during Direct Oral Anticoagulant Introduction in Gynecologic Malignancies: A Single-Center Retrospective Cohort Study

The risk factors for venous thromboembolism (VTE) recurrence/exacerbation or a change from a direct oral anticoagulant (DOAC) to another anticoagulant in patients with gynecologic cancer using DOACs have not been thoroughly elucidated. Here, we aimed to investigate the risk factors for a composite primary outcome, including VTE recurrence/exacerbation, or a change from a DOAC to another anticoagulant, in this population. A total of 63 patients were analyzed. Risk factors for a primary outcome within 2 years after DOAC initiation were investigated using multiple logistic regression analysis. Among the 63 patients, 10 developed a primary outcome. Clear cell carcinoma of the ovary (adjusted odds ratio (aOR), 18.9; 95% confidence interval (CI), 2.25-350.74), pulmonary embolism (PE) or proximal deep vein thrombosis without PE (aOR, 55.6; 95% CI, 3.29-11,774.66), and D-dimer levels in the third tertile (≥7.6 μg/dL) when VTE was first diagnosed (aOR, 6.37; 95% CI, 1.17-66.61) were associated with increased odds of a primary outcome in patients with gynecologic cancer using DOACs. Patients with one or more risk factors for a primary outcome require careful follow-up after DOAC initiation for the early recognition of treatment failure.

Comparison of the efficacy and safety of rivaroxaban and low-molecular-weight heparin in Chinese lung cancer patients with nonhigh-risk pulmonary embolism

BACKGROUND

Data that guide selection of differing anticoagulant regimens for specific cancer-associated venous thromboembolism (VTE) are lacking. We aimed to compare the efficacy and safety of rivaroxaban and low-molecular-weight heparin (LMWH) against nonhigh-risk pulmonary embolism (PE) in Chinese lung cancer patients.

METHODS

Four hundred forty-six Chinese lung cancer patients with nonhigh-risk PE who initiated treatment with rivaroxaban or LMWH were identified from Zhongshan Hospital database from 2016 to 2020. The primary outcomes were the composite event of VTE recurrence or major bleeding, and all-cause mortality. The secondary outcomes were VTE recurrence, major bleeding and clinically relevant non-major bleeding (CRNMB). Propensity score matching was used to balance baseline covariates. We conducted sensitivity analysis by stabilized inverse probability of treatment weighting and competing risk analysis by a Fine and Gray subdistribution hazard model.

RESULTS

In propensity score-matched cohorts, rivaroxaban was similar to LMWH in the risks of the composite outcome (hazard ratio (HR), 0.73; 95% confidence interval (CI), 0.45-1.21; P = 0.22), VTE recurrence (HR, 0.69; 95% CI, 0.36-1.34; P = 0.28), major bleeding (HR, 0.79; 95% CI, 0.37-1.68; P = 0.54) and CRNMB (HR, 1.13; 95% CI, 0.62-2.09; P = 0.69). All-cause mortality was significantly lower in rivaroxaban group than LMWH group (HR, 0.52; 95% CI, 0.36-0.75; P < 0.001). The primary and secondary outcomes favored rivaroxaban over LMWH in all the subgroups expect for central PE and intermediate-risk PE. The sensitivity analysis yielded similar results, and competing risk analysis was in accordance with the primary findings.

CONCLUSIONS

Rivaroxaban might be a promising alternative to LMWH as initial treatment for nonhigh-risk PE in lung cancer patients.

Does COVID-19 infection increase the risk of pulmonary embolism in ambulatory patients with deep vein thrombosis

OBJECTIVES

Coronavirus disease 2019 (COVID-19) can lead to systemic coagulation activation and thrombotic complications including venous thromboembolism. This study compares the development of pulmonary embolism, post-thrombotic syndrome, and clinical outcomes of COVID-19 and non-COVID-19 patients with deep vein thrombosis (DVT).

METHODS

One hundred and eight patients diagnosed with acute deep vein thrombosis (DVT) between June 2020 and February 2021 in our institution were included in this retrospective study. Thirty-nine patients had been previously diagnosed with COVID-19 and specified as the COVID-19 group. Sixty-nine patients did not have COVID-19 and specified as the non-COVID-19 group. Mean ages of both groups were 64.3 ± 15.8 and 60.1 ± 19.7 years, respectively (p = .37).

RESULTS

The median duration from the onset of the COVID-19 to diagnosis of DVT was 22 (2-120) days in the COVID-19 group. The patients of two groups were mostly treated outpatient at rates of 94.9% vs 94.2%, respectively (p = .88). Pulmonary embolism was seen in six patients (15.4%) in the COVID-19 group and in three patients (4.3%) in the non-COVID-19 group (p = .04). Kaplan-Meir curves showed that patients with COVİD-19 had significantly higher pulmonary embolism than those without COVID-19 (p = .015). The recurrence rate of DVT was 2.6% in the COVID-19 group (n = 1), and 4.3% in the non-COVID-19 group (n = 3), indicating no statistically significant difference (p = .63). Mortality was seen in six patients (15.4%) in the COVİD-19 group, and in seven patients (10.1%) in the non-COVID-19 group. According to the Kaplan-Meir method, 10 months survival rates were 73.9 ± 10% in the COVID-19 group, and 66.3 ± 12.8% in the non-COVID-19 group with no statistical significance (p = .218).

CONCLUSIONS

Our data draw attention to the fact that deep vein thrombosis should not be considered a safe and self-limited condition. Efficient preventive measures such as mobilization and prophylactic drug use should be considered to prevent DVT during the management of COVID-19.

Effectiveness and safety of the direct oral anticoagulant in acute distal deep vein thrombosis: From the prospective multicenter observational study, J'xactly, in Japan

OBJECTIVES

We assessed the effectiveness and safety of rivaroxaban in patients with isolated distal deep vein thrombosis (IDDVT).

METHODS

Symptomatic venous thromboembolism (VTE) and major bleeding were assessed.

RESULTS

Of 1016 patients with acute symptomatic/asymptomatic DVT and/or pulmonary embolism treated with rivaroxaban, 288 had IDDVT and 294 had proximal DVT (pDVT). The IDDVT group had fewer patients on the higher rivaroxaban dose (30 mg/day) (42.7% vs. 66.0%) and a shorter treatment duration (135.5 vs 369.5 days) than the pDVT group. VTE recurrence occurred in 14 and 11 patients with IDDVT and pDVT, respectively (2.89% vs. 2.29% per patient-year; p = 0.534). Major bleeding was less frequent in the IDDVT group (1.55% vs. 4.53% per patient-year; p = 0.044). Comparable effectiveness and safety were observed with 15 and 30 mg/day rivaroxaban in the IDDVT group.

CONCLUSIONS

Short-term, low-dose rivaroxaban seems safe and effective for IDDVT treatment.

36-month clinical outcomes of patients with venous thromboembolism: GARFIELD-VTE

BACKGROUND

Venous thromboembolism (VTE), encompassing both deep vein thrombosis (DVT) and pulmonary embolism (PE), is a leading cause of morbidity and mortality worldwide.

METHODS

GARFIELD-VTE is a prospective, non-interventional observational study of real-world treatment practices. We aimed to capture the 36-month clinical outcomes of 10,679 patients with objectively confirmed VTE enrolled between May 2014 and January 2017 from 415 sites in 28 countries.

FINDINGS

A total of 6582 (61.6 %) patients had DVT alone, 4097 (38.4 %) had PE ± DVT. At baseline, 98.1 % of patients received anticoagulation (AC) with or without other modalities of therapy. The proportion of patients on AC therapy decreased over time: 87.6 % at 3 months, 73.0 % at 6 months, 54.2 % at 12 months and 42.0 % at 36 months. At 12-months follow-up, the incidences (95 % confidence interval [CI]) of all-cause mortality, recurrent VTE and major bleeding were 6.5 (7.0-8.1), 5.4 (4.9-5.9) and 2.7 (2.4-3.0) per 100 person-years, respectively. At 36-months, these decreased to 4.4 (4.2-4.7), 3.5 (3.2-2.7) and 1.4 (1.3-1.6) per 100 person-years, respectively. Over 36-months, the rate of all-cause mortality and major bleeds were highest in patients treated with parenteral therapy (PAR) versus oral anti-coagulants (OAC) and no OAC, and the rate of recurrent VTE was highest in patients on no OAC versus those on PAR and OAC. The most frequent cause of death after 36-month follow-up was cancer (n = 565, 48.6 %), followed by cardiac (n = 94, 8.1 %), and VTE (n = 38, 3.2 %). Most recurrent VTE events were DVT alone (n = 564, 63.3 %), with the remainder PE, (n = 236, 27.3 %), or PE in combination with DVT (n = 63, 7.3 %).

INTERPRETATION

GARFIELD-VTE provides a global perspective of anticoagulation patterns and highlights the accumulation of events within the first 12 months after diagnosis. These findings may help identify treatment gaps for subsequent interventions to improve patient outcomes in this patient population.

A Description of Apixaban Dosing Patterns for Treatment or Prevention of Thrombotic Events in Hospitalized Patients on Dialysis

Introduction: Apixaban is currently the only oral direct factor Xa inhibitor approved for treatment and prevention of venous thromboembolism (VTE) in patients on hemodialysis. Exclusion of dialysis patients from major clinical trials results in prescriber uncertainty regarding the optimal dose of apixaban for VTE treatment in this population. This study sought to characterize the variance in apixaban prescribing patterns for thrombotic indications other than atrial fibrillation. Methods: This retrospective, multi-center, descriptive study analyzed apixaban dosing patterns for hospitalized chronic dialysis patients with history of thrombosis. The primary outcome was incidence of deviation from manufacturer recommendations for dosing, assessed for either a new start or receipt prior to hospitalization. Secondary outcomes included observation of recurrent thrombotic and bleeding event rates during subsequent hospitalizations. Patients were analyzed into subgroups according to type of thrombotic indication for treatment. Data are reported with descriptive statistics. Results: A total of 101 patients were included. Deviations in recommended dosing were observed in 53 of 80 (66.2%) patients receiving apixaban for treatment of acute or chronic thrombosis. Of 44 patients started on apixaban during hospitalization for the indication of acute VTE, a dose deviation was observed in 79.5% of patients. Rates of rehospitalization for recurrent thrombotic events and bleeding were 11.8% and 9.9%, respectively. Conclusion: Variation in apixaban prescribing practices for the treatment of VTE in dialysis patients is common, suggesting an urgent need for prospective studies and updated dosing guidance to optimize safety with apixaban use in this population.

Evaluation of newly-developed modified diluted prothrombin time reagent in non-valvular atrial fibrillation patients with direct oral anticoagulants: A comparative study with conventional reagents

INTRODUCTION

A single assay to assess the effect of the direct FXa inhibitor is needed clinically because prothrombin (PT) assay is not yet sensitive enough for accurate evaluation. We developed modified diluted prothrombin time (mdPT) assay showing a high reactivity to direct FXa inhibitors based on prothrombin time (PT) reagent. The purpose of this study was to evaluate the reactivity of mdPT to direct FXa inhibitors comparing to that of commercial PT reagents and diluted prothrombin time (dPT).

METHODS

The correlation and slopes of mdPT against the drug concentrations by anti-Xa assay were compared to those of the four commercial reagents of PT or dPT in 275, 257, and 243 clinical samples collected from non-valvular atrial fibrillation (NVAF) patients who are prescribed apixaban, edoxaban or rivaroxaban for stroke prevention, respectively.

RESULTS

The correlation coefficient (95% confidence interval) of mdPT against apixaban, edoxaban, and rivaroxaban was 0.818 (0.775-0.854), 0.914 (0.892-0.932), and 0.814 (0.766-0.852), respectively. The slope (95% confidence interval) of mdPT for apixaban, edoxaban, and rivaroxaban was 0.0068 (0.0063-0.0075), 0.0076 (0.0072-0.0080), and 0.0072 (0.0065-0.0078), respectively, which were higher than that of four commercial PT and dPT reagents, ranging within 0.0006-0.0023, 0.0017-0.0038, and 0.0016-0.0057 (all, p < 0.001), respectively.

CONCLUSION

Compared with other PT and dPT reagents, mdPT reagent showed sharper slope to all direct FXa inhibitors, and higher correlation to apixaban and comparable correlation to edoxaban and rivaroxaban. This new reagent is expected to be a coagulation screening assay having a consistently high response to any types of direct FXa inhibitors.

Anti-factor Xa activity, prothrombin time, and activated partial thromboplastin time in patients treated with factor Xa inhibitors

The regimens for factor Xa (FXa) inhibitors (apixaban, edoxaban, and rivaroxaban) vary with venous thromboembolism (VTE) or non-valvular atrial fibrillation (NVAF). The dosage and duration of FXa inhibitor therapy also differ. However, the distribution of anti-factor Xa activity (AXA) values, prothrombin time (PT), and activated partial thromboplastin time (APTT) in patients administered each FXa inhibitor has not fully been assessed. Trough and peak AXA values, PT, and APTT were measured in 85 patients taking apixaban, 105 patients taking edoxaban, and 27 patients taking rivaroxaban. The patients were further divided into three groups based on the dosage. Each FXa inhibitor showed various ranges of AXA values, and twice-daily use resulted in higher absolute AXA values than once-daily use. AXA values and PT for 20 mg apixaban at both trough and peak times were significantly higher than those for 5 mg or 10 mg. AXA values for 60 mg edoxaban at peak time were significantly higher than those for 15 mg or 30 mg. AXA values for 30 mg of rivaroxaban at both trough and peak times were significantly higher than those for 10 mg or 15 mg. In a nonlinear regression model of the relationship between AXA and PT or APTT, PT was positively correlated with AXA values for each FXa inhibitor. This study obtained trough and peak levels of AXA, PT, and APTT in patients with VTE or NVAF who were administered apixaban, edoxaban, and rivaroxaban.

Are Factor Xa Inhibitors Efficacious for Ischemic Stroke Prevention in Patients Without Atrial Fibrillation? Evidence From Randomized Clinical Trials

BACKGROUND

Clinical trials provide conflicting evidence regarding oral factor Xa inhibitors for prevention of ischemic stroke in patients without a history of atrial fibrillation (AF).

METHODS

We performed a critical appraisal of randomized clinical trials that tested oral factor Xa inhibitors in patients without AF that reported ischemic stroke.

RESULTS

Considering the 11 trials that reported > 10 ischemic strokes during follow-up (97,578 participants, 1195 ischemic strokes), 1 tested apixaban (57 strokes), 1 betrixaban (52 strokes), and 9 rivaroxaban (1086 strokes). In 7 trials with placebo comparisons, numerically fewer ischemic strokes occurred among those assigned factor Xa inhibitors in 7 of 8 randomized comparisons (range of hazard ratios [HRs], 0.89-0.51), including statistically significant reductions in 2 trials that compared rivaroxaban 2.5 mg twice daily vs placebo on a background of aspirin in patients with cardiovascular disease, COMPASS (HR, 0.51; 95% confidence interval [CI], 0.38-0.68) and COMMANDER-HF (HR, 0.64; 95% CI, 0.43-0.95). Compared with aspirin in 4 trials, oral factor Xa inhibitors were associated with fewer ischemic strokes in 2, with statistically significant reduction in 1 (rivaroxaban 5 mg twice daily in COMPASS; HR, 0.69; 95% CI, 0.53-0.90). Major bleeding was increased by oral factor Xa inhibitors in all 7 placebo-controlled trials (HR range, 1.42-4.08), with statistically significant increases reported in 5 trials, and in all 4 aspirin-controlled trials (all statistically significant increases; HR range, 1.52-2.72).

CONCLUSIONS

Aggregate evidence on the basis of placebo comparisons from randomized trials supports the potential for oral factor Xa inhibitors to reduce ischemic stroke in patients without AF, but major bleeding is increased.

Risk of bleeding with factor Xa inhibitors versus unfractionated heparin in patients with acute kidney injury

STUDY OBJECTIVE

To compare bleeding and thromboembolic events in patients receiving therapeutic doses of apixaban or rivaroxaban versus unfractionated heparin (UFH) in patients with acute kidney injury (AKI).

DESIGN

Single-center, retrospective, observational study.

SETTING

Ascension St. John Hospital in Detroit, Michigan.

PATIENTS

Hospitalized adult patients who received therapeutic doses of factor Xa inhibitors (n = 250) or UFH (n = 250) for at least 24 h in the setting of AKI.

MEASUREMENTS AND MAIN RESULTS

After adjusting for confounding factors, patients who received a factor Xa inhibitor experienced a lower risk of composite major and clinically relevant nonmajor bleeding (CRNMB) events compared with UFH (OR: 0.57, 95% CI: 0.34-0.94; p = 0.03). There was a significantly decreased risk of CRNMB events in the factor Xa inhibitor group (OR: 0.55, 95% CI: 0.33-0.91, p = 0.02); however, no significant differences in major bleeding or venous thromboembolism (VTE) were noted.

CONCLUSIONS

Our results suggest that it may be preferable to continue patients in AKI on factor Xa inhibitors versus transitioning to UFH due to the lower risk of bleeding events.

Effect of Rivaroxaban vs Enoxaparin on Major Cardiac Adverse Events and Bleeding Risk in the Acute Phase of Acute Coronary Syndrome: The H-REPLACE Randomized Equivalence and Noninferiority Trial

IMPORTANCE

Parenteral enoxaparin is a preferred anticoagulant used in the acute phase for patients with acute coronary syndrome (ACS). The safety and efficacy of short-term low-dose rivaroxaban in this clinical setting remain unknown.

OBJECTIVE

To compare the safety and efficacy of rivaroxaban vs enoxaparin in the acute phase of ACS.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter, prospective, open-label, active-controlled, equivalence and noninferiority trial was conducted from January 2017 through May 2021 with a 6-month follow-up at 21 hospitals in China. Participants included patients with ACS missing the primary reperfusion window or before selective revascularization. Data were analyzed from November 2021 to November 2022.

INTERVENTIONS

Participants were randomized 1:1:1 to oral rivaroxaban 2.5 mg or 5 mg or 1 mg/kg subcutaneous enoxaparin twice daily in addition to dual antiplatelet therapy (DAPT; aspirin 100 mg and clopidogrel 75 mg once daily) for a mean of 3.7 days.

MAIN OUTCOMES AND MEASURES

The primary safety end point was bleeding events, as defined by the International Society on Thrombosis and Haemostasis, and the primary efficacy end point was major adverse cardiovascular events (MACEs), including cardiac death, myocardial infarction, rerevascularization, or stroke during the 6-month follow-up.

RESULTS

Of 2055 enrolled patients, 2046 (99.6%) completed the trial (mean [SD] age 65.8 [8.2] years, 1443 [70.5%] male) and were randomized to enoxaparin (680 patients), rivaroxaban 2.5 mg (683 patients), or rivaroxaban 5 mg (683 patients). Bleeding rates were 46 patients (6.8%) in the enoxaparin group, 32 patients (4.7%) in the rivaroxaban 2.5 mg group, and 36 patients (5.3%)in the rivaroxaban 5 mg group (rivaroxaban 2.5 mg vs enoxaparin: noninferiority hazard ratio [HR], 0.68; 95% CI, 0.43 to 1.07; P = .005; rivaroxaban 5 mg vs enoxaparin: noninferiority HR, 0.88; 95% CI, 0.70 to 1.09; P = .001). The incidence of MACEs was similar among groups, and noninferiority was reached in the rivaroxaban 5 mg group (HR, 0.60; 95% CI, 0.31 to 1.16, P = .02) but not in the rivaroxaban 2.5 mg group (HR, 0.68; 95% CI, 0.36 to 1.30; P = .05) compared with the enoxaparin group.

CONCLUSIONS AND RELEVANCE

In this equivalence and noninferiority trial, oral rivaroxaban 5 mg showed noninferiority to subcutaneous enoxaparin (1 mg/kg) for patients with ACS treated with DAPT during the acute phase. Results of this feasibility study provide useful information for designing future randomized clinical trials with sufficient sample sizes.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03363035.

The usefulness of tranexamic acid for bleeding symptoms of chronic consumptive coagulopathy complicated by aortic disease: a single-institute, retrospective study of 14 patients

BACKGROUND

Tranexamic acid (TXA) is an antifibrinolytic drug that blocks lysine-binding sites on the profibrinolytic enzyme plasminogen. Aortic diseases with chronic consumption coagulopathy may lead to disseminated intravascular coagulation (DIC) and cause fatal bleeding. Although the use of antifibrinolytic agents in DIC is generally not recommended due to enhanced fibrin deposition risking thrombotic symptoms, the efficacy of TXA has been reported in several cases of DIC with aortic diseases. However, the efficacy and safety of TXA for bleeding symptoms of chronic consumption coagulopathy with aortic diseases have not been studied in detail.

METHODS

We evaluated the efficacy of TXA in 14 patients with chronic consumptive coagulopathy due to aortic disease complicated by bleeding symptoms. Changes in coagulation and fibrinolysis parameters from baseline were analyzed with Wilcoxon matched-pairs signed-rank tests, excluding missing values. Kaplan-Meier curves were used to analyze overall survival.

RESULTS

Median age was 78.5 years (range, 66-89 years) and median observation period was 448 days (range, 0-2282 days). Twelve patients had chronic renal failure and 1 patient had chronic liver failure. Before starting treatment, median Japanese Ministry of Health and Welfare DIC diagnostic criteria score was 8 (range, 4-11) and median platelet count was 64 × 10⁹/L (range, 25-97 × 10⁹/L). Twelve patients underwent evaluation of bleeding symptoms after introduction of TXA, and 10 of those 12 patients showed improved bleeding tendencies within 30 days (median, 5.0 days). One patient with chronic liver failure showed worsening of bleeding symptoms. Although only one patient was initiated TXA in combination with anticoagulants, no significant worsening of thrombotic events was observed within 30 days.

CONCLUSIONS

TXA therapy appears effective against chronic consumptive coagulopathy with bleeding due to aortic disease, with few side effects.

Warfarin Time in Therapeutic INR Range and Direct Oral Anticoagulant Adherence for Venous Thromboembolism Across the Spectrum of Weight and Body Mass Index: Findings from Veterans Health Administration

The evidence of direct oral anticoagulants (DOACs) usage for venous thromboembolism (VTE) in patients at extremes of body weight or mass index is limited. In such situations, warfarin may be more frequently used. We investigated warfarin time in the therapeutic international normalized ratio range (TTR) and DOAC adherence based on the calculated proportion of days covered (PDC) by pill coverage from a DOAC prescription in patients with VTE across all body sizes. Using data from the Veterans Health Administration (VA), we identified first-time patients with VTE between 2013 and 2018 treated with warfarin or DOACs. We analyzed 28,245 patients with warfarin TTR (N  =  10,167) or DOAC PDC(N  =  18,078). For warfarin-treated patients after index VTE, mean TTR was lower over shorter treatment durations (TTR 30 vs TTR 180 [mean  ±  SD]: 43.8% ± 33.5% vs 58.8% ± 23.5%). Mean TTR over 180 days after VTE was lowest for patients <60 kg (TTR 180 [mean  ±  SD]: <60kg: 49.3% ± 24.2% vs ≥60 to <100 kg: 57.8% ± 23.4%; P < .0001). For DOAC-treated patients over 180 days after index VTE, mean PDC was lowest for patients <60 kg (PDC 180 [mean  ±  SD]: < 60kg: 76.9% ± 33.2% vs ≥ 60 to <100 kg: 83.6% ± 27.7%; P < .0001).Most DOAC-treated patients attained sufficient adherence across the body size spectrum while warfarin-treated patients <60kg were at risk for low TTR.

Shedding Light on the Pathogenesis of Splanchnic Vein Thrombosis

Splanchnic vein thrombosis is a rare but potentially life-threatening manifestation of venous thromboembolism, with challenging implications both at the pathological and therapeutic level. It is frequently associated with liver cirrhosis, but it could also be provoked by myeloproliferative disorders, cancer of various gastroenterological origin, abdominal infections and thrombophilia. A portion of splanchnic vein thrombosis is still classified as idiopathic. Here, we review the mechanisms of splanchnic vein thrombosis, including new insights on the role of clonal hematopoiesis in idiopathic SVT pathogenesis, with important implications from the therapeutic standpoint.

A Real-World Cost-Effectiveness Analysis of Rivaroxaban versus Vitamin K Antagonists for the Treatment of Symptomatic Venous Thromboembolism: Lessons from the REMOTEV Registry

Background and objectives: Venous thromboembolism (VTE) represents a health and economic burden with consequent healthcare resource utilization. Direct oral anticoagulants (DOACs) have emerged as the mainstay option for VTE treatment but few data exist on their cost-effectiveness as compared to the standard therapy (vitamin K antagonists (VKAs)). This study aimed to assess the cost-effectiveness of rivaroxaban compared to VKAs in VTE treatment by calculating the incremental cost effectiveness ratio (ICER). Materials and methods: We conducted a prospective observational study based on the REMOTEV registry, including patients hospitalized for VTE from 23 October 2013 to 31 July 2015, to evaluate the impact of the anticoagulant treatment (DOACs versus VKAs) on 6-month complications: major or clinically relevant non-major bleeding, VTE recurrence and all-cause death. Rivaroxaban was the only DOAC prescribed in this study. The ICER was calculated as the difference in costs divided by the difference in effectiveness. Results: Among the 373 patients included, 279 were treated with rivaroxaban (63.1 ± 17.9 years old; 49% men) and 94 with VKAs (71.3 ± 16.6 years old; 46% men). The mean cost was EUR 5662 [95% CI 6606; 9060] for rivaroxaban and EUR 7721 [95% CI 5130; 6304] for VKAs, while effectiveness was 0.0586 95% CI [0.0114; 0.126] for DOACs and 0.0638 [95% CI 0.0208; 0.109] for VKAs. The rivaroxaban treatment strategy was dominant with costs per patient EUR 2059 lower [95% CI -3582; -817] and a higher effectiveness of 0.00527 [95% CI -0.0606; 0.0761] compared to VKAs. Conclusions: This study provides real-world evidence that rivaroxaban is not only an efficient and safe alternative to VKAs for eligible VTE patients, but also cost-saving.

Impact of Heart Rate at Diagnosis on Clinical Outcomes in Patients With Acute Pulmonary Embolism

Data on the impact of heart rate (HR) at diagnosis on clinical outcomes in patients with acute pulmonary embolism (PE) remain scarce. The present study population consisted of 1,532 patients with PE; the patients were divided into 4 groups, including (1) HR <80 beats/min (n = 451, 29%), (2) 80 ≤HR <100 beats/min (n = 620, 40%), (3) 100 ≤HR <110 beats/min (n = 215, 14%), and (4) HR ≥110 beats/min (n = 246, 16%). The cumulative 30-day incidences of all-cause death were significantly higher in the 100 ≤HR <110 and HR ≥110 beats/min groups than in the HR <80 beats/min group. Incidences were 2.7%, 3.6%, 6.6%, and 5.7% (p = 0.04) in the HR <80 beats/min, 80 ≤HR <100 beats/min, 100 ≤HR <110 beats/min, and HR ≥110 beats/min groups, respectively. With the HR <80 beats/min group as reference, the 100 ≤HR <110 and HR ≥110 groups, but not the 80 ≤HR <100 group, were significantly associated with an increased risk of 30-day all-cause death. Hazard ratio was 2.53 (95% confidence interval [CI] 1.17 to 5.56, p = 0.02) for the 80 ≤HR <100 beats/min group, 2.20 (95% CI 1.02 to 4.84, p = 0.046) for the 100 ≤HR <110 beats/min group, and 1.34 (95% CI 0.67 to 2.79, p = 0.41) for the HR ≥110 beats/min group. The cumulative 30-day incidences of all-cause death in patients with simplified Pulmonary Embolism Severity Index score = 0 were 0.6%, 0.3%, and 0.7% when based on cut-off values of HR ≥110 beats/min, HR ≥100 beats/min, and ≥80 beats/min, respectively. Patients with moderate tachycardia (100 ≤HR <110) seemed to be at comparable risk of 30-day all-cause death to those with HR ≥110 beats/min and at higher risk of 30-day all-cause death than those with HR <80 beats/min; this may suggest a potential benefit of the alternative cut-off value of HR ≥100 beats/min in the simplified Pulmonary Embolism Severity Index score for identification of low-risk patients.

UK prescribing practice of anticoagulants in patients with chronic kidney disease: a nephrology and haematology-based survey

A survey to gain insight into anticoagulant prescribing practice in the setting of chronic kidney disease (CKD) across the UK was disseminated via renal and haematology networks. Areas of anticoagulant use included patients with venous thromboembolism (VTE), requiring thromboprophylaxis for VTE, Atrial Fibrillation (AF) and nephrotic syndrome.An online-survey was disseminated via British Haematology Society, UK Kidney Association, and Renal Pharmacy Group over a five month period. All responses were voluntary and anonymous.Among 117 responses there were 49 nephrology doctors, 47 renal pharmacists and 20 haematology clinicians. A specialist multidisciplinary team to discuss the specific anticoagulant management of these patients was only available to 3% (4/117) respondents. Renal function estimate used for anticoagulant dosing was mainly Cockcroft-Gault for pharmacists and haematology but lab-based estimates were used by nephrology doctors. Therapeutic dose of Low Molecular Weight Heparin was mostly likely to be reduced by one-third when used for VTE treatment, with the majority of units undertaking anti-Xa monitoring in CKD stage 5 and dialysis. Direct-acting Oral Anticoagulants are being used in patients with nephrotic syndrome, those with CKD stage 5 and on dialysis for VTE and AF in the absence of license in these indications.This survey highlighted the significant differences between anticoagulant prescribing in CKD between two professional specialties and marked variation between centres in anticoagulant management strategies employed for these patients. With gaps still existing in the evidence base and answers to these not expected within the next few years, development of a best-practice guideline would be warranted to support clinicians in this field.

Bleeding Risk in Elderly Patients with Venous Thromboembolism Who Would Have Been Excluded from Anticoagulation Trials

Older patients with venous thromboembolism (VTE) are underrepresented in clinical anticoagulation trials. We examined to which extent elderly patients with VTE would be excluded from such trials and compared the bleeding risk between hypothetically excluded and enrolled patients. We studied 991 patients aged ≥65 years with acute VTE in a prospective multicenter cohort. We identified 12 landmark VTE oral anticoagulation trials from the eighth and updated ninth American College of Chest Physician Guidelines. For each trial, we abstracted the exclusion criteria and calculated the proportion of our study patients who would have been excluded from trial participation. We examined the association between five common exclusion criteria (hemodynamic instability, high bleeding risk, comorbidity, co-medication, and invasive treatments) and major bleeding (MB) within 36 months using competing risk regression, adjusting for age, sex, and periods of anticoagulation. A median of 31% (range: 20-52%) of our patients would have been excluded from participation in the landmark trials. Hemodynamic instability (sub-hazard ratio [SHR]: 2.2, 95% CI: 1.1-4.7), comorbidity (SHR: 1.5, 95% CI: 1.1-2.2), and co-medication (SHR: 1.5, 95% CI: 1.0-2.3) were associated with MB. Compared to eligible patients, those with ≥2 exclusion criteria had a twofold (SHR: 2.16, 95% CI: 1.38-3.39) increased risk of MB. Overall, about one-third of older patients would not be eligible for participation in guideline-defining VTE anticoagulation trials. The bleeding risk increases significantly with the number of exclusion criteria present. Thus, results from such trials may not be generalizable to older, multimorbid, and co-medicated patients.

Real-World Evaluation of the Safety and Effectiveness of Apixaban & Rivaroxaban Lead-in Dosing Compared to Parenteral Lead-in Dosing in the Treatment of Venous Thromboembolism: A Multi-Center Retrospective Cohort Study

Background

Although parenteral anticoagulation lead-in is not recommended with apixaban and rivaroxaban, parenteral anticoagulation is often used to replace apixaban or rivaroxaban lead-in doses for the initial phase treatment of VTE. Thus, our study compares the safety and effectiveness of lead-in parenteral anticoagulation to lead-in apixaban or rivaroxaban in patients who received apixaban or rivaroxaban for VTE treatment.

Methods

A multi-center retrospective cohort study included adult patients (aged ≥ 18 years) admitted to the hospital with acute VTE and treated with either apixaban or rivaroxaban. Patients were grouped depending on the lead-in anticoagulation received for initial VTE treatment into the "Direct oral anticoagulation (DOAC) lead-in" group if patients received an appropriate lead-in dose of apixaban and rivaroxaban and patients who received parenteral lead-in the "parenteral lead-in" group.

Results

A total of 389 patients were included; the DOAC lead-in group included 296 patients, whereas 93 patients were in the parenteral lead-in group. VTE recurrence (rVTE) during hospitalization and within 30 days was numerically higher in the parenteral lead-in group compared to the DOAC lead-in group (3.3% vs 0.6%; p=0.09 and 1.1% vs 0.7%; p=0.560), with a significantly higher number of patients with rVTE at 90 days (5.4% vs 1.4%; p=0.039). However, none of the patient's characteristics were significantly associated with the incidence of rVTE. In addition, the major bleeding rate during hospitalization was significantly higher among the parenteral lead-in group than in the DOAC lead-in group (14.0% vs 3.7%; p<0.001).

Conclusion

Parenteral anticoagulation lead-in before starting maintenance of apixaban and rivaroxaban showed a significantly higher risk of bleeding and a trend toward higher VTE recurrence than the DOAC lead-in. This study adds to the evidence supporting the utilization of the DOAC lead-in regimen in treating patients with VTE. Still, larger studies with robust designs are needed to confirm these findings.

Protocol for a modelling study to assess the clinical and cost-effectiveness of indefinite anticoagulant therapy for first unprovoked venous thromboembolism

INTRODUCTION

Deciding whether to stop or extend anticoagulant therapy indefinitely after completing at least 3 months of initial treatment for a first unprovoked venous thromboembolism (VTE) remains a challenge for clinicians, patients and policy makers. Guidelines suggest an indefinite duration of anticoagulant therapy in these patients, yet its benefits, harms and costs have not been formally assessed. The aim of this proposed modelling study is to assess the differences in clinical benefits, harms and costs of stopping versus continuing anticoagulant therapy indefinitely for a first unprovoked VTE.

METHODS AND ANALYSIS

We will develop a probabilistic Markov model, adopting a 1-month cycle length and a lifetime horizon, to estimate life-years, quality-adjusted life-years, costs and the incremental cost-effectiveness ratios for a simulated population of patients with a first unprovoked VTE who will receive indefinite duration of anticoagulant therapy versus a population who will not receive extended treatment after completing 3 months of initial anticoagulant therapy. The economic evaluation will adopt a third-party payer perspective relating to a Canadian publicly funded healthcare system. Estimates for the probability of relevant clinical events will be informed by systematic reviews and meta-analyses, while costs and utility values will be obtained from published Canadian sources. Stratified analyses based on sex, age and site of initial VTE will also be performed to identify subgroups of patients with a first unprovoked VTE in whom continuing anticoagulant therapy indefinitely might prove to be clinically beneficial and cost-effective over stopping treatment. We will also conduct sensitivity and scenario analyses to assess robustness of study findings to changes in individual or groups of key parameters.

ETHICS AND DISSEMINATION

Ethical approval is not applicable for this study. The results will be disseminated through presentations at relevant conferences and in a manuscript that will be submitted to a peer-reviewed journal.

Direct Oral Anticoagulants vs Vitamin K Antagonists in Patients With Antiphospholipid Syndromes: Meta-Analysis of Randomized Trials

BACKGROUND

The efficacy and safety of direct oral anticoagulants (DOACs) for patients with thrombotic antiphospholipid syndrome remain controversial.

OBJECTIVES

The authors performed a systematic review and meta-analysis of randomized controlled trials that compared DOACs with vitamin K antagonists (VKAs).

METHODS

We searched PubMed, EMBASE, and Cochrane Central Register of Controlled Trials through April 9, 2022. The 2 main efficacy outcomes were a composite of arterial thrombotic events and venous thromboembolic events (VTEs). The main safety outcome was major bleeding. Random effects models with inverse variance were used.

RESULTS

Our search retrieved 253 studies. Four open-label randomized controlled trials involving 472 patients were included (mean control-arm time-in-therapeutic-range 60%). All had proper random sequence generation and adequate allocation concealment. Overall, the use of DOACs compared with VKAs was associated with increased odds of subsequent arterial thrombotic events (OR: 5.43; 95% CI: 1.87-15.75; P < 0.001, I2 = 0%), especially stroke, and the composite of arterial thrombotic events or VTE (OR: 4.46; 95% CI: 1.12-17.84; P = 0.03, I2 = 0%). The odds of subsequent VTE (OR: 1.20; 95% CI: 0.31-4.55; P = 0.79, I2 = 0%), or major bleeding (OR: 1.02; 95% CI: 0.42-2.47; P = 0.97; I2 = 0%) were not significantly different between the 2 groups. Most findings were consistent within subgroups.

CONCLUSIONS

Patients with thrombotic antiphospholipid syndrome randomized to DOACs compared with VKAs appear to have increased risk for arterial thrombosis. No significant differences were observed between patients randomized to DOACs vs VKAs in the risk of subsequent VTE or major bleeding.

Influence of primary cancer site on clinical outcomes of anticoagulation for associated venous thromboembolism

INTRODUCTION

The outcome of anticoagulation for cancer-associated venous thromboembolism (Ca-VTE) differs according to cancer location, but data are limited and inconsistent.

MATERIALS AND METHODS

Patients with acute venous thromboembolism (VTE) enrolled between 03/01/2013 and 04/30/2021 were followed prospectively to assess VTE recurrence, major bleeding (MB), clinically relevant non-major bleeding (CRNMB), and death.

RESULTS

There were 1702 (45.3 %) patients with Ca-VTE including: gastrointestinal (n = 340), pancreatic (n = 223), hematologic (n = 188), genitourinary (n = 163), lung (n = 139), ovarian (n = 109), breast (n = 97), renal (n = 75), prostate (n = 73), hepatobiliary (n = 70), brain (n = 57), and other cancers (n = 168); 2057 VTE patients had no cancer (NoCa-VTE). Hepatobiliary cancer had the highest VTE recurrence (all rates 100 person-years) of all cancers and higher compared to NoCa-VTE (13.69, p = 0.01), while the MB rate, although numerically higher (15.91), was not different (p = 0.09). Another 3 cancers had higher VTE recurrence but similar MB rates compared to NoCa-VTE: genitourinary [(9.59, p = 0.01) and (7.03, p = 1.0)], pancreatic [(9.74, p < 0.001) and (5.47, p = 1.00)], and hematologic [(5.29, p = 0.05) and (3.59, p = 1.0)]. Renal cancer had the highest rate of MB among all cancers and was higher than that of NoCa-VTE (16.49; p < 0.001), with no difference in VTE recurrence (1.62; p = 1.0). VTE recurrence and MB rates were not significantly different between NoCa-VTE and gastrointestinal, lung, breast, prostate, and brain cancers. CRNMB rates were similar and mortality higher in Ca-VTE patients, except for prostate and breast cancer, compared to NoCa-VTE.

CONCLUSIONS

Significant differences in clinical outcomes indicate that anticoagulation strategies may need to be tailored to the primary cancer location.

Association Between Postoperative Complications and Long-term Survival After Non-cardiac Surgery Among Veterans

OBJECTIVE

To evaluate the relationship between postoperative complications and long-term survival.

SUMMARY AND BACKGROUND

Postoperative complications remain a significant driver of healthcare costs and are associated with increased perioperative mortality, yet the extent to which they are associated with long-term survival is unclear.

METHODS

National cohort study of Veterans who underwent non-cardiac surgery using data from the Veterans Affairs Surgical Quality Improvement Program (2011-2016). Patients were classified as having undergone outpatient, low-risk inpatient, or high-risk inpatient surgery. Patients were categorized based on number and type of complications. The association between the number of complications (or the specific type of complication) and risk of death was evaluated using multivariable Cox regression with robust standard errors using a 90-day survival landmark.

RESULTS

Among 699,002 patients, complication rates were 3.0%, 6.1%, and 18.3% for outpatient, low-risk inpatient, and high-risk inpatient surgery, respectively. There was a dose-response relationship between an increasing number of complications and overall risk of death in all operative settings [outpatient surgery: no complications (ref); one-hazard ratio (HR) 1.30 (1.23 - 1.38); multiple-HR 1.61 (1.46 - 1.78); low-risk inpatient surgery: one-HR 1.34 (1.26 - 1.41); multiple-HR 1.69 (1.55 - 1.85); high-risk inpatient surgery: one-HR 1.14 (1.10 - 1.18); multiple-HR 1.42 (1.36 - 1.48)]. All complication types were associated with risk of death in at least 1 operative setting, and pulmonary complications, sepsis, and clostridium difficile colitis were associated with higher risk of death across all settings. Conclusions: Postoperative complications have an adverse impact on patients' long-term survival beyond the immediate postoperative period. Although most research and quality improvement initiatives primarily focus on the perioperative impact of complications, these data suggest they also have important longer-term implications that merit further investigation.

Evaluation of Patient Characteristics Linked to Major Bleeding Events in Patients Prescribed Direct Oral Anticoagulants

INTRODUCTION

Direct oral anticoagulants (DOACs) demonstrated similar efficacy and lower risk of intracranial hemorrhage than warfarin in patients with atrial fibrillation and venous thromboembolism. Given the lack of data identifying risk factors in patients who bled while on a DOAC, we sought to investigate these characteristics.

MATERIALS AND METHODS

This retrospective chart review was approved by the Mass General Brigham Institutional Review Board and assessed patients who experienced bleeding events while on DOAC therapy from 6/1/2015 to 7/1/2020. Patient characteristics were evaluated, including age, sex, body mass index (BMI), renal function, concomitant therapies, and baseline comorbidities.

RESULTS

Eighty-seven patients were included for analysis, with a median age of 75.8 years. Most patients were female (51.7%) and 24 (27.6%) had a BMI >30. At time-of-event, 21 patients (24.1%) had acute kidney injury. Thirty-three patients (37.9%) were on concomitant antiplatelet therapy (APT), with 31 (35.6%) on single APT and 2 on dual APT. Pertinent comorbidities included hypertension (74.7%), ischemic cerebrovascular accident (28.7%), thyroid abnormality (23.0%), active cancer (14.9%), and anemia (13.8%). Eleven patients (12.6%) had a prior bleeding event. Most patients were on apixaban (69.0%) for the indication of stroke prevention in nonvalvular atrial fibrillation/flutter (72.4%). FDA-approved dosing was used in most patients (92.0%), and all deviations reflected underdosing. Most bleeding events were defined as major (95.4%), occurred at a critical organ site (72.4%), and developed spontaneously (58.6%).

CONCLUSIONS

These data provide insight into characteristics of patients who experience bleeding events while on DOAC therapy. Understanding these potential risk factors may optimize the safe use of these agents.

To Measure or Not to Measure: Direct Oral Anticoagulant Laboratory Assay Monitoring in Clinical Practice

The need for therapeutic drug monitoring of direct oral anticoagulants (DOACs) remains an area of clinical equipoise. Although routine monitoring may be unnecessary given predictable pharmacokinetics in most patients, there may be altered pharmacokinetics in those with end organ dysfunction, such as those with renal impairment, or with concomitant interacting medications, at extremes of body weight or age, or in those with thromboembolic events in atypical locations. We aimed to assess real-world practices in situations in which DOAC drug-level monitoring was used at a large academic medical center. A retrospective review of the records of patients who had a DOAC drug-specific activity level checked from 2016 to 2019 was included. A total of 119 patients had 144 DOAC measurements (apixaban (n = 62) and rivaroxaban (n = 57)). Drug-specific calibrated DOAC levels were within an expected therapeutic range for 110 levels(76%), with 21 levels (15%) above the expected range and 13 levels (9%) below the expected range. The DOAC levels were checked in the setting of an urgent or emergent procedure in 28 patients (24%), followed by renal failure in 17 patients (14%), a bleeding event in 11 patients (9%), concern for recurrent thromboembolism in 10 patients (8%), thrombophilia in 9 patients (8%), a history of recurrent thromboembolism in 6 patients (5%), extremes of body weight in 7 patients (5%), and unknown reasons in 7 patients (5%). Clinical decision making was infrequently affected by the DOAC monitoring. Therapeutic drug monitoring with DOACs may help predict bleeding events in elderly patients, those with impaired renal function, and in the event of an emergent or urgent procedure. Future studies are needed to target the select patient-specific scenarios where monitoring DOAC levels may impact clinical outcomes.

Effectiveness and Safety of Direct Oral Anticoagulants Among Octogenarians with Venous Thromboembolism: An International Multidatabase Cohort Study

BACKGROUND

The effects of direct oral anticoagulants (DOACs) among octogenarian patients with venous thromboembolism remains poorly understood. To address this knowledge gap, our study aimed to assess the effectiveness and safety of DOACs compared to vitamin K antagonists (VKAs) among octogenarians with venous thromboembolism.

METHODS

We conducted an international cohort study using administrative health care databases from Québec, Canada, and Germany. We assembled 2 population-based cohorts of octogenarians with incident venous thromboembolism initiating treatment with DOACs or VKAs. The study period spanned from January 2012 to the most recent date of data availability (Québec: December 2016; Germany: December 2019). Using an as-treated exposure definition, we compared use of DOACs to use of VKAs, applying inverse probability of treatment weighting based on high-dimensional propensity scores to balance exposure groups. Cox proportional hazards models estimated site-specific hazard ratios (HRs) and 95% confidence intervals (CIs) of recurrent venous thromboembolism, major bleeding, and all-cause mortality. The results were meta-analyzed using random-effects models.

RESULTS

Overall, our study included 6737 octogenarians with venous thromboembolism (Québec: n = 2556; Germany: n = 4181) who initiated use of DOACs (n = 3778) or VKAs (n = 2959). When compared to VKAs, DOACs were associated with similar risks of recurrent venous thromboembolism (weighted HR, 0.80; 95% CI, 0.43-1.46; I² = 0.00), major bleeding (weighted HR, 0.96; 95% CI, 0.57-1.63; I² = 0.59), and all-cause mortality (weighted HR, 1.04; 95% CI, 0.81-1.34; I² = 0.00).

CONCLUSIONS

Among octogenarians with venous thromboembolism, DOACs showed a comparable effectiveness and safety compared to VKAs. Our results support the use of DOACs in this high-risk group.

Direct Oral Anticoagulants for Inferior Vena Cava Agenesis

Deep vein thrombosis (DVT) is common in the general population, with an annual incidence of 1 to 2 per 1000 people. Inferior vena cava agenesis (IVCA) increased the risk of developing DVT and is found in approximately 5% of young adults (20-40-year-olds) diagnosed with unprovoked proximal DVT. IVCA can be caused by a defective embryological process, or be a result of intrauterine or perinatal thrombosis. Its estimated incidence in the general population ranges from 0.0005% to 1%, usually involving a partial absence of one of the four segments of the inferior vena cava (IVC). The management during the extended phase of patients with DVT associated with IVCA is not yet harmonized, as it is poorly described in the literature. Patients with IVCA are considered to be at high risk of DVT occurrence, prompting physicians to continue extended anticoagulation, often using vitamin K antagonists. In this retrospective study, we present a cohort of 11 patients diagnosed with IVCA following a DVT, who subsequently received extended treatment with a direct oral anticoagulants. These findings offer reassuring insights into the extended utilization of direct oral anticoagulants, demonstrating both antithrombotic efficacy and a favorable safety profile.

Anticoagulation in older people with atrial fibrillation moving to care homes: a data linkage study

BACKGROUND

Treatment decisions about oral anticoagulants (OACs) for atrial fibrillation (AF) are complex in older care home residents.

AIM

To explore factors associated with OAC prescription.

DESIGN AND SETTING

Retrospective cohort study set in care homes in Wales, UK, listed in the Care Inspectorate Wales Registry 2017/18.

METHOD

Analysis of anonymised individual-level electronic health and administrative data was carried out on people aged ≥65 years entering a care home between 1 January 2003 and 31 December 2018, provisioned from the Secure Anonymised Information Linkage Databank.

RESULTS

Between 2003 and 2018, 14 493 people with AF aged ≥65 years became new residents in care homes in Wales and 7057 (48.7%) were prescribed OACs (32.7% in 2003 compared with 72.7% in 2018) within 6 months before care home entry. Increasing age and prescription of antiplatelet therapy were associated with lower odds of OAC prescription (adjusted odds ratio [aOR] 0.96 per 1-year age increase, 95% confidence interval [CI] = 0.95 to 0.96 and aOR 0.91, 95% CI = 0.84 to 0.98, respectively). Conversely, prior venous thromboembolism (aOR 4.06, 95% CI = 3.17 to 5.20), advancing frailty (mild: aOR 4.61, 95% CI = 3.95 to 5.38; moderate: aOR 6.69, 95% CI = 5.74 to 7.80; and severe: aOR 8.42, 95% CI = 7.16 to 9.90), and year of care home entry from 2011 onwards (aOR 1.91, 95% CI = 1.76 to 2.06) were associated with higher odds of an OAC prescription.

CONCLUSION

There has been an increase in OAC prescribing in older people newly admitted to care homes with AF. This study provides an insight into the factors influencing OAC prescribing in this population.

Rivaroxaban vs. warfarin for the treatment and prevention of venous thromboembolism: A meta-analysis

Background

Anticoagulant treatment is used to treat and prevent venous thromboembolism (VTE). However, the relative effectiveness of newer anticoagulants vs. warfarin has not been appraised.

Objective

The aim was to evaluate the safety and efficacy of rivaroxaban for VTE in comparison to warfarin.

Materials and methods

From January 2000 until October 2021, all related studies were collected by EMBASE, the Cochrane Library, PubMed and Web of Scienceand. During the review process, two reviewers independently analyzed the included studies, including quality evaluation, screening and data extraction. We focused on VTE events as our primary outcomes.

Results

In total, 20 trials were retrieved. These studies involved 230,320 patients, of which 74,018 received rivaroxaban and 156,302 received warfarin. Compared with warfarin, the incidence of VTE in rivaroxaban is significantly lower (risk ratio (RR) 0.71, 95% confidence interval (CI) [0.61, 0.84]; P < 0.0001, random effect model), and significantly reduced major [RR: 0.84, 95% CI (0.77, 0.91); P < 0.0001, fixed effect model] and nonmajor [RR: 0.55, 95% CI (0.41, 0.74); P < 0.0001, fixed effect model] bleeding. No significant differences in all-cause mortality between the two groups [RR: 0.68, 95% CI (0.45, 1.02); P = 0.06, fixed effect model].

Conclusion

Rivaroxaban significantly reduced the incidence of VTE compared to warfarin in this meta-analysis. In order to verify these findings, larger sample sizes are required in well-designed studies.

Risk and Management of Bleeding Complications with Direct Oral Anticoagulants in Patients with Atrial Fibrillation and Venous Thromboembolism: a Narrative Review

Atrial fibrillation (AF) and venous thromboembolism (VTE) are highly prevalent conditions with a significant healthcare burden, and represent the main indications for anticoagulation. Direct oral anticoagulants (DOACs) are the first choice treatment of AF/VTE, and have become the most prescribed class of anticoagulants globally, overtaking vitamin K antagonists (VKAs). Compared to VKAs, DOACs have a similar or better efficacy/safety profile, with reduced risk of intracerebral hemorrhage (ICH), while the risk of major bleeding and other bleeding harms may vary depending on the type of DOAC. We have critically reviewed available evidence from randomized controlled trials and observational studies regarding the risk of bleeding complications of DOACs compared to VKAs in patients with AF and VTE. Special patient populations (e.g., elderly, extreme body weights, chronic kidney disease) have specifically been addressed. Management of bleeding complications and possible resumption of anticoagulation, in particular after ICH and gastrointestinal bleeding, are also discussed. Finally, some suggestions are provided to choose the optimal DOAC to minimize adverse events according to individual patient characteristics and bleeding risk.