Oral rivaroxaban for symptomatic venous thromboembolism

Anticoagulant for treatment and prophylaxis of venous thromboembolism patients with renal dysfunction: A systematic review and network meta-analysis

Objective

The aim of this study was to compare the efficacy and safety for particular regimen and dosage in venous thromboembolism (VTE) patients with renal insufficiency.

Methods

English language searches of PubMed, Embase, and Web of Science (inception to May 2021). RCTs evaluating anticoagulants for VTE treatment at acute phase, extension phase, and VTE prophylaxis in patients with renal insufficiency and reporting efficacy (death, recurrence, or occurrence of VTE) and safety (bleeding) outcomes were selected. The methodological quality of each study included was assessed at the outcome level using the risk-of-bias assessment tool developed by the Cochrane Bias Methods Group.

Results

Twenty-one trials that involved 76,574 participants and 8,972 (11.7%) patients with renal insufficiency were enrolled, including 10 trials on VTE treatment in acute phase (3–12 months), four trials on VTE treatment in extension phase (6–36 months), and seven trials for VTE prophylaxis. For acute VTE treatment, compared with dabigatran etexilate, apixaban (RR 5.90, 95%CI 1.00–34.60) and rivaroxaban (RR 6.18, 95%CI 1.17–32.75) were significantly associated with increased risk of death or recurrence. For extension treatment of VTE, aspirin had the highest probability of the most effective and safest treatment, followed by apixaban. For VTE prophylaxis, compared with enoxaparin, desirudin was associated with lower risk of VTE occurrence (RR 0.56, 95% CI 0.34–0.91), but had higher risk of bleeding than dabigatran etexilate.

Conclusion

The network meta-analysis informs the optimal choice of anticoagulants and their particular dosage for treatment and prophylaxis of VTE patients comorbid renal insufficiency.

Systematic review registration

www.crd.york.ac.uk/prospero/, identifier: CRD42021254086.

Pulmonary Embolism Readmission Trend Over the Years (from a National Readmission Database)

With the evolution of pulmonary embolism (PE) management, the outcomes of PE-related complications and the need for readmission have not been well studied. The aim of this study is to see the trend in readmissions in patients with PE from 2010 to 2018. We used the National Readmission Database from 2010 to 2018 to identify hospitalized patients with a principal diagnosis of acute PE. We then identified the total number of readmissions for acute PE from 2010 to 2018. These were further stratified based on readmission within 30 days and readmission within 90 days. A multivariate Cox regression model was used to adjust for confounding factors. The 30-day all-cause readmission after principal admission for PE decreased from 11.2% to 9.7% from 2010 to 2014 but increased to 11.8% in 2018 (p <0.001). A similar trend was seen in 90-day readmission. Risk-adjusted readmission specific for PE showed a decrease from 1.2% to 1% (p = 0.004) in the 30-day cohort and from 1.4% to 1.2% (p = 0.006) in the 90-day cohort from 2010 to 2018. When adjusted to age and gender, an increase in the proportion of readmissions with intracranial bleeding was seen among both the 30-day (0.7% in 2010 to 1.2% in 2018, adjusted odds ratio [aOR] 1.06, p = 0.006) and 90-day (0.7% in 2010 to 1.2% in 2018, aOR 1.06, p-trend = 0.003) cohorts. Similarly, an increasing trend of readmissions for upper gastrointestinal bleed was seen among both 30-day (0.9% vs 4.3%, aOR 1.26, p-trend <0.001) and 90-day (0.7% vs 3.8%, aOR 1.27, p-trend <0.001) readmissions. Our study suggests that there is a statistically significant decrease in PE-specific readmission from 2010 to 2018 but a variable trend in all-cause readmissions. We also report an increase in bleeding during readmissions, including intracranial hemorrhage and upper gastrointestinal bleed. In conclusion, these findings warrant further studies to elucidate the mechanism for decreasing PE-specific readmission and possible causes for the increase in all-cause readmissions.

Effectiveness and safety of apixaban vs warfarin among venous thromboembolism patients at high-risk of bleeding

This study evaluated effectiveness and safety of apixaban versus warfarin among venous thromboembolism patients at high-risk of bleeding (defined as having at least one of the following bleeding risk factors: ≥75 years; used antiplatelet, NSAIDs, or corticosteroids; had prior gastrointestinal bleeding or gastrointestinal-related conditions; late stage chronic kidney disease). Adult venous thromboembolism patients initiating apixaban or warfarin with ≥1 bleeding risk factor were identified from Medicare and four commercial claims databases in the United States. To balance characteristics between apixaban and warfarin patients, stabilized inverse probability treatment weighting was conducted. Cox proportional hazards models were used to estimate the risk of recurrent venous thromboembolism, major bleeding, and clinically relevant non-major bleeding. In total, 88,281 patients were identified. After inverse probability treatment weighting, the baseline patient characteristics were well-balanced between the two cohorts. Among venous thromboembolism patients at high-risk of bleeding, apixaban was associated with significantly lower risk of recurrent venous thromboembolism, major bleeding and clinically relevant non-major bleeding. No significant interactions were observed between treatment and number of risk factors on major bleeding and clinically relevant non-major bleeding or between treatment and type of bleeding risk factors on any of the outcomes. In conclusion, apixaban was associated with significantly lower risk of recurrent venous thromboembolism and bleeding among venous thromboembolism patients at high-risk of bleeding. Effects were generally consistent across subgroups of patients with different number or type of bleeding risk factors.

Spontaneous epidural hematoma induced by rivaroxaban: A case report and review of the literature

Background:

Trauma is the most frequent reason for epidural bleeding. However, numerous investigation had discovered that anticoagulants such as rivaroxaban could cause epidural hematoma. Here, we present a case of epidural hematoma in young man who got rivaroxaban as treatment of deep vein thrombosis.

Case Description:

A 27-year-old male with a history of deep vein thrombosis and one month of rivaroxaban medication presented with seizure and loss of consciousness following a severe headache. A CT scan of the head revealed epidural bleeding, and emergency blood clot removal was performed. As a reversal, prothrombin complex was utilized.

Conclusion:

Rivaroxaban has the potential to cause an epidural hemorrhage. Reversal anticoagulant should be administered before doing emergency surgery.

Recurrent thromboembolism, bleeding, and mortality in Asian patients with venous thromboembolism receiving different oral anticoagulants: A nationwide analysis

Venous thromboembolism (VTE) is associated with a high risk of morbidity and mortality. However, data on the association between oral anticoagulants and the hazards of VTE complications in Taiwanese patients with VTE is limited. This study aimed to compare the hazards of recurrent VTE, bleeding, and mortality between patients with VTE receiving rivaroxaban, a non-vitamin K antagonist oral anticoagulant (NOAC), and those receiving heparin or low-molecular-weight heparin (LMWH) followed by warfarin. Patients with VTE treated with rivaroxaban, or heparin or LMWH followed by warfarin were enrolled from 2 million random samples from Taiwan's National Health Insurance database between 2013 and 2016. Hazards of recurrent VTE (deep vein thrombosis and pulmonary embolism), major bleeding, and mortality in rivaroxaban and warfarin users were investigated. Survival analyses were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Users of rivaroxaban (183) and warfarin (456) were included in the study. Patients receiving rivaroxaban did not have significantly lower hazards of developing recurrent VTE (HR, 0.72 [CI, 0.37-1.37], P = .31) and mortality (HR, 0.86 [CI, 0.49-1.50], P = .59) than those receiving heparin or LMWH followed by warfarin. In addition, the hazard ratio of major bleeding was not significantly different between the 2 regimens (HR, 1.80 [CI, 0.39-8.29], P = .45). Rivaroxaban was not associated with lower risks of recurrent VTE and mortality and higher hazards of major bleeding than heparin or LMWH followed by warfarin in Taiwanese patients with VTE. Clinicians may tailor oral anticoagulants for VTE patients according to the patient's characteristics, cost-effectiveness and healthcare system policy.

A ten-year review of the impact of the transition from warfarin to direct oral anticoagulant - Has venous thromboembolism treatment become safer?

BACKGROUND

The introduction of direct oral anticoagulants (DOAC) has resulted in a paradigm shift in the management of venous thromboembolism (VTE). We evaluate the impact of the transition to DOAC, over the last decade, on overall VTE clinical outcomes including in first unprovoked major VTEs.

METHOD

A retrospective analysis of all VTE admissions in non-cancer patients from January 2011 to December 2020 at Northern Health, Victoria, Australia. "Warfarin era" included events that occurred between January 2011 and December 2014 and "DOAC era" from January 2016.

RESULTS

There were 2687 cases involving 2508 patients (45.9 % males; median age 63 years). 98 % were symptomatic and 1261 events (47 %) were unprovoked. 1003 events occurred during the warfarin era (79 % warfarin, 6 % DOAC) and 1479 during the DOAC era (18 % warfarin, 70 % DOAC). While recurrent thrombosis during the acute phase of treatment was comparable, there were fewer recurrences during the long-term preventative phase of treatment in the DOAC era compared to warfarin era (HR 0.602, 95 % CI: 0.393-0.924, p0.020). Clinically significant bleeding events were lower in the DOAC era (HR 0.623, 95 % CI: 0.395-0.985, p = 0.043). A subanalysis of first unprovoked major VTE events (n = 602) demonstrated a significant reduction in recurrent VTE during the long-term preventative phase of treatment in the DOAC era (HR 0.296, 95 % CI: 0.097-0.901, p = 0.032) with no difference in clinically significantly bleeding rates (HR 0.529, 95 % CI 0.219-1.280, p = 0.158) between the eras.

CONCLUSION

Treatment outcomes for VTE appear to have improved over time with reduced rate of thrombotic and clinically significant bleeding complications in the DOAC era.

Outcome of anticoagulation with rivaroxaban in patients with non-retrieved inferior vena cava filters for the prevention of filter thrombosis: a retrospective cohort study

Background

Non-retrieved inferior vena cava filter (IVCF) is associated with some severe complications, such as filter thrombosis. The aim of this retrospective cohort study was to evaluate the outcome of rivaroxaban for the prevention of filter thrombosis in patients with non-retrieved IVCF.

Methods

The study based on the VTE registry databases was limited to patients with non-retrieved IVCF treated at Nanjing Drum Tower Hospital from January 2012 to December 2017. Outcomes included filter thrombosis, total bleeding events, death.

Results

A total of 202 patients were enrolled in the study and divided into rivaroxaban group and warfarin group. Mean follow-up period of the two groups was 57.4 ± 20.8 and 62.2 ± 23.0 months, respectively. In risk factors for VTE, transient factors (P = 0.008) and history of VTE (P = 0.028) were statistically different between the two groups. A total of 13 (6.4%) patients developed filter complications, of which 4 (3.5%) and 5 (5.7%) patients in rivaroxaban group and warfarin group developed filter thrombosis, respectively, without significant difference (P = 0.690). The total bleeding events in rivaroxaban group, including major bleeding and clinically relevant and non-major (CRNM) bleeding, were significantly lower than that in warfarin group (P = 0.005). Adjusting for hypertension, transient risk factors, history of VTE and cancer, no differences in the hazard ratio for outcomes were notable.

Conclusions

It is necessary to perform a concomitant anticoagulation in patients with non-retrieved filters. Rivaroxaban can be an alternative anticoagulant option for the prevention of filter thrombosis.

Causes of long-term mortality in patients with venous thromboembolism in the real world: From the COMMAND VTE registry

INTRODUCTION

There is still a scarcity of data on causes of long-term mortality in patients with venous thromboembolism (VTE).

MATERIALS AND METHODS

The COMMAND VTE Registry is a physician-initiated, retrospective, multicenter cohort study in which consecutive 3027 patients with acute symptomatic VTE among 29 centers in Japan were included between January 2010 and August 2014. We investigated detailed causes and risk factors for long-term mortality.

RESULTS

During a median observation period of 1218 days, a total of 764 patients died, and the prevalence of active cancer was higher in patients who died than in patients alive (61 % versus 10 %, P < 0.001). The cumulative incidences of cardiac death, pulmonary embolism (PE)-related death, bleeding death, cancer death, and non-cardiovascular non-cancer death were 2.2 %, 2.9 %, 2.0 %, 16.1 %, and 6.7 % at 5 years, respectively. The incidence of cancer death increased gradually, which was the most common cause of long-term death. Among patients without active cancer, the incidence of PE-related death increased rapidly and became a plateau beyond the acute phase, whereas the incidence of non-cardiovascular non-cancer death kept increasing, which became most common in the long term. The separate multivariable analysis among patient with and without active cancer identified independent risk factors of all-cause death including a few patient characteristics among patients with active cancer and several patient characteristics among patients without active cancer.

CONCLUSIONS

Cancer was the most common cause of long-term mortality, while non-cardiovascular non-cancer death became most common among patients without active cancer.

Warfarin is associated with higher rates of epistaxis compared to direct oral anticoagulants: A nationwide propensity score-weighted study

BACKGROUND

Although epistaxis is one of the most common side effects of oral anticoagulation, it is unclear whether epistaxis rates vary between different oral anticoagulants (OAC).

OBJECTIVE

To compare rates of clinically relevant epistaxis between OAC.

METHODS

Epistaxis event rates were compared between new users of apixaban, dabigatran, rivaroxaban, and warfarin in a nationwide population-based cohort study over a 5-year study period, 2014-2019. Data was collected from the Icelandic Medicine Registry and the five major hospitals in Iceland. Inverse probability weighting (IPW) was used to yield balanced baseline characteristics, and epistaxis rates were compared using Kaplan-Meier survival estimates and Cox regression.

RESULTS

During the study period, 2098 patients received apixaban, 474 dabigatran, 3106 rivaroxaban, and 1403 warfarin. In total, 93 patients presented with clinically relevant epistaxis, including 11 (12%) major epistaxis events and one fatal epistaxis episode. Furthermore, seven patients (9%) with non-major epistaxis later presented with major bleeding during the follow-up period. Warfarin use was associated with higher rates of epistaxis compared to apixaban (2.2 events per 100-person years (events/100-py) vs. 0.6 events/100-py, hazard ratio [HR] 4.22, 95% confidence interval [CI] 2.08-8.59, p < 0.001), rivaroxaban (2.2 events/100-py vs. 1.0 events/100-py, HR 2.26, 95% CI 1.28-4.01, p = 0.005), and dabigatran (2.2 events/100-py vs. no events, HR n/a, p < 0.001).

CONCLUSION

Warfarin treatment was associated with higher rates of clinically relevant epistaxis compared to direct oral anticoagulants.

Anticoagulation and BMI: effect of high body weight on the safety and efficacy of direct oral anticoagulants

Obesity is an epidemic with rising prevalence, and obese patients are predisposed to comorbid conditions that increase risk for thromboembolic events. It is critical to identify safe and effective anticoagulation therapy for use in this population. Direct oral anticoagulants (DOACs) are a preferred option for anticoagulation in patients of normal weight due to many benefits and equivalent safety and efficacy to their vitamin K antagonist counterparts. However, the safety and efficacy of DOACs in obese patients is not well understood. This review describes recent studies on the pharmacokinetics, safety and efficacy, and clinical outcomes of the DOACs apixaban, rivaroxaban, edoxaban and dabigatran in obese patient populations. DOACs may be a beneficial alternative to vitamin K antagonist therapy in obese patient populations.

Comparative effectiveness and safety of edoxaban, rivaroxaban, and apixaban in patients with venous thromboembolism: A cohort study

BACKGROUND

Although several studies have compared the effectiveness and safety of rivaroxaban and apixaban in patients with venous thromboembolism (VTE), direct comparison of these drugs with edoxaban is lacking.

OBJECTIVE

We compared the effectiveness and safety of edoxaban, rivaroxaban, and apixaban in patients with VTE.

PATIENTS/METHODS

In this retrospective cohort study using a Japanese hospital administrative database, we identified three mutually exclusive groups of patients with VTE beginning treatment with edoxaban, rivaroxaban, or apixaban. Primary effectiveness outcome was recurrent VTE, and principal safety outcome was a composite of intracranial hemorrhage and gastrointestinal bleeding. Subjects were followed for up to 180 days. Baseline characteristics among groups were balanced using propensity score matching weights.

RESULTS

Three thousand three hundred sixty-nine edoxaban, 1592 rivaroxaban, and 1998 apixaban initiators were identified. There were no significant differences among the three drugs in the prevention of recurrent VTE (adjusted incidence rate ratio [aIRR], 0.77; 95% confidence interval [CI], 0.45-1.30 for edoxaban vs. rivaroxaban; aIRR, 0.92; 95% CI, 0.54-1.56 for edoxaban vs. apixaban; and aIRR, 1.20; 95% CI, 0.69-2.10 for rivaroxaban vs. apixaban), or in the risk of intracranial hemorrhage or gastrointestinal bleeding (aIRR, 1.57, 95% CI, 0.85-2.90 for edoxaban vs. rivaroxaban; aIRR, 1.30, 95% CI, 0.76-2.23 for edoxaban vs. apixaban; and aIRR, 0.83, 95% CI, 0.42-1.64 for rivaroxaban vs. apixaban).

CONCLUSIONS

In routine care, edoxaban, rivaroxaban, and apixaban appear to have similar effectiveness and safety in the treatment of VTE.

Therapeutic potential and molecular mechanisms of salidroside in ischemic diseases

Rhodiola is an ancient wild plant that grows in rock areas in high-altitude mountains with a widespread habitat in Asia, Europe, and America. From empirical belief to research studies, Rhodiola has undergone a long history of discovery, and has been used as traditional medicine in many countries and regions for treating high-altitude sickness, anoxia, resisting stress or fatigue, and for promoting longevity. Salidroside, a phenylpropanoid glycoside, is the main active component found in all species of Rhodiola. Salidroside could enhance cell survival and angiogenesis while suppressing oxidative stress and inflammation, and thereby has been considered a potential compound for treating ischemia and ischemic injury. In this article, we highlight the recent advances in salidroside in treating ischemic diseases, such as cerebral ischemia, ischemic heart disease, liver ischemia, ischemic acute kidney injury and lower limb ischemia. Furthermore, we also discuss the pharmacological functions and underlying molecular mechanisms. To our knowledge, this review is the first one that covers the protective effects of salidroside on different ischemia-related disease.

Hemostatic and thrombotic disorders in the pediatric patient

This review focuses on significant advances in the field of pediatric hemostasis and thrombosis, with a focus on published studies within the past decade. The evaluation and management of patients with excessive bleeding remain cornerstones of consultative hematology. We will describe the development of validated bleeding assessment tools relevant to pediatric practice, laboratory advances in the evaluation of von Willebrand disease, and a shift in clinical practice regarding the interpretation of normal coagulation studies in patients with significant bleeding phenotypes. There have also been critical advances in the management of hemostatic disorders. This review highlights new treatment paradigms in hemophilia and the rise of multidisciplinary medical homes for women living with bleeding disorders. Given the continued increase in the incidence of thrombosis, particularly in the hospital setting, a full call to arms against pediatric venous thromboembolism is now essential. We will describe recently completed clinical trials of direct oral anticoagulants in children and adolescents and ongoing work to elucidate the appropriate duration of therapy for children with provoked thrombosis. Recent work regarding the prevention of pediatric venous thromboembolism is highlighted, including studies of thromboprophylaxis and the development of risk prediction models for hospital-acquired thrombosis. Finally, we review advances in our understanding of thrombotic sequelae and the need for continued refinement of our evaluation tools. Despite the significant advances in pediatric hemostasis and thrombosis over the past decade, many unanswered questions remain for the next generation of investigators.

Trends in post-discharge prophylactic anticoagulant use among stroke patients in the United States between 2006 and 2019

BACKGROUND

Stroke is an independent risk factor for venous thromboembolism (VTE). Although the risk of VTE persists after hospital discharge, information on the utilization of anticoagulants among stroke patients after discharge remains limited.

OBJECTIVE

To evaluate changes in post-discharge thromboprophylaxis among stroke patients between 2006 and 2019.

METHODS

We conducted a retrospective repeated cross-sectional analysis using a commercial healthcare insurance database in the United States. We included patients aged ≥ 18 years with incident stroke diagnosis and assessed prophylactic use of anticoagulants in the 30 days following hospital discharge including low-molecular-weight heparin (enoxaparin ≤40 mg/day, dalteparin ≤5000 IU/day), unfractionated heparin ≤5000 IU/ twice daily or 3 times a day, apixaban 2.5 mg twice daily, and rivaroxaban 10 mg/day. Patients with atrial fibrillation, VTE, mechanical heart valves, cancer, antiphospholipid antibody syndrome, and users of therapeutic doses of anticoagulants were excluded. We used the Cochrane-Armitage test to assess changes in the use of anticoagulants across the study period.

RESULTS

There was a small increase in the overall use of post-discharge prophylactic anticoagulants among stroke patients between 2006 and 2019 from 0.5% to 1.9%. The use of heparin decreased from 0.5% in 2006 to 0.3% in 2019 (P-value for trend = 0.001). In contrast, the use of apixaban or rivaroxaban increased from 0.1% in 2013 to 1.6% in 2019 (P-value for trend < 0.001). Apixaban was more commonly used than rivaroxaban.

CONCLUSIONS

In this population-based study of stroke patients, we found that post-discharge anticoagulant use remains low through 2019. Prophylactic use of heparin or rivaroxaban was relatively low but the use of apixaban increased over the study period. Further research is needed to determine if these agents are safe and effective for VTE prevention in stroke patients.

Cyclic RGD functionalized PLGA nanoparticles loaded with noncovalent complex of indocyanine green with urokinase for synergistic thrombolysis

Thrombotic diseases have the characteristics of long latency period, rapid onset, and high mortality rate, which seriously threaten people’s life and health. The aim of this research is to fabricate a novel indocyanine green complex of urokinase (ICG@uPA) and employ the amphiphilic PEG-PLGA polymer to deliver the complex as an enzyme-phototherapeutic synergistic thrombolysis platform. The noncovalent indocyanine green (ICG) complex of urokinase (ICG@uPA) was prepared via supramolecular self-assembly and then encapsulated into cRGD decorated polymeric nanoparticles (cRGD-ICG-uPA NPs) by double-emulsion solvent evaporation method. Then the nanoparticles (NPs) were characterized in terms of particle size, optical properties, in vitro release, etc. The targeting and thrombolytic effect of the nanoparticles were studied both in vitro and in vivo. ICG@uPA and cRGD-ICG-uPA NPs displayed significantly higher photostability and laser energy conversion efficiency than free ICG. Concomitantly, the NPs exhibited selective binding affinity to the activated platelets and specific accumulation in the mouse mesenteric vessel thrombus. Significant thrombolysis was achieved in vivo by photo-assisted synergistic therapy with reduced dose and systemic bleeding risk of uPA. Our results prove that the functional PLGA nanoparticle loaded with the ICG@uPA offers a novel option for effective and safe thrombolytic treatment.

Direct Oral Anticoagulants Versus Vitamin K Antagonists in Cerebral Venous Thrombosis: A Systematic Review and Meta-Analysis

BACKGROUND

High level evidence for direct oral anticoagulants (DOACs) in patients with cerebral venous thrombosis is lacking. We performed a systematic review and meta-analysis to assess the efficacy and safety of DOACs versus vitamin K antagonists in patients with cerebral venous thrombosis.

METHODS

This systematic review was registered in PROSPERO (CRD42021228800). We searched MEDLINE (via Ovid), EMBASE, CINAHL, and the Web of Science Core Collection between January 1, 2007 and Feb 22, 2022. Search terms included a combination of keywords and controlled vocabulary terms for cerebral venous thrombosis, vitamin K antagonists/warfarin, and DOACs. We included both randomized and nonrandomized studies that compared vitamin K antagonists and DOACs in 5 or more patients with cerebral venous thrombosis. Where studies were sufficiently similar, we performed meta-analyses for efficacy (recurrent venous thromboembolism and complete recanalization) and safety (major hemorrhage) outcomes, using relative risks (RRs).

RESULTS

Out of 10 665 records identified, we screened 254 as potentially eligible. Nineteen studies (16 observational studies [n=1735] and 3 randomized controlled trials [n=215]) met the inclusion criteria. All 3 randomized controlled trials had some concerns, and all 16 observational studies had at least moderate risk of bias. When compared with vitamin K antagonist treatment, DOAC had comparable risks of recurrent venous thromboembolism (relative risk [RR], 0.85 [95% CI, 0.52-1.37], I²=0%), major hemorrhage (RR, 0.70 [95% CI, 0.40-1.21], I²=0%), intracranial hemorrhage (RR, 0.58 [95% CI, 0.30-1.12]; I²=0%), death (RR, 1.14 [95% CI, 0.54-2.43], I²=1%), and complete venous recanalization (RR, 0.98 [95% CI, 0.87-1.11]; I²=0%).

CONCLUSIONS

This systematic review and meta-analysis suggest that in patients with cerebral venous thrombosis, DOACs, and warfarin may have comparable efficacy and safety. Given the limitations of the studies included (low number of randomized controlled trials, modest total sample size, rare outcome events), our findings should be interpreted with caution pending confirmation by ongoing randomized controlled trials and large, prospective, observational studies.

Stroke Prevention in Atrial Fibrillation: A Scientific Statement of JACC: Asia (Part 1)

Atrial fibrillation is the most common sustained cardiac arrhythmia and is associated with substantial increases in the risk of stroke and systemic thromboembolism. With the successful introduction of the first non-vitamin K antagonist direct oral anticoagulant (NOAC) in 2009, the role of vitamin K antagonists has been replaced in most clinical settings except in a few conditions when NOACs are contraindicated. Data for the use of NOACs in different clinical scenarios have been accumulating in the recent decade, and a more sophisticated strategy for atrial fibrillation patients is now warranted. JACC: Asia recently appointed a working group to summarize the most updated information regarding stroke prevention in AF. This statement aimed to provide possible treatment option in daily practice. Local availability, cost, and patient comorbidities should also be considered. Final decisions may still need to be individualized and based on clinicians' discretion. This is the part 1 of the whole statement.

How Would You Treat This Patient With Pulmonary Embolism? : Grand Rounds Discussion From Beth Israel Deaconess Medical Center

Pulmonary embolism can be acutely life-threatening and is associated with long-term consequences such as recurrent venous thromboembolism and chronic thromboembolic pulmonary hypertension. In 2020, the American Society of Hematology published updated guidelines on the management of patients with venous thromboembolism. Here, a hematologist and a cardiology and vascular medicine specialist discuss these guidelines in the context of the care of a patient with pulmonary embolism. They discuss advanced therapies such as catheter-directed thrombolysis in the short-term management of patients with intermediate-risk disease, recurrence risk stratification at presentation, and ideal antithrombotic regimens for patients whose pulmonary embolism was associated with a transient minor risk factor.

Evaluation of safety and efficacy outcomes of direct oral anticoagulants versus warfarin in normal and extreme body weights for the treatment of atrial fibrillation or venous thromboembolism

Despite evolving evidence, the use of direct oral anticoagulants (DOACs) in patients with extremes of body weight remains controversial. This study aimed to measure the impact of DOACs compared to warfarin on safety and efficacy outcomes in extreme body weight patients. This multi-center, health system, retrospective study examined the outcomes of patients with all body weights and extreme body weights prescribed a DOAC (rivaroxaban, apixaban, dabigatran, edoxaban) or warfarin for atrial fibrillation or venous thromboembolism over a 9-year period. The primary outcome was a composite of thromboembolism, symptomatic recurrent VTE, or severe bleeding; analyzed by pre-determined BMI cutoffs. A total of 19,697 patients were included in the study: 11,604 in the DOAC group and in the 8093 in the warfarin group. 295 patients were underweight and 9108 patients were pre-obese to obese class 3. After adjusting for potential confounders, warfarin patients had higher odds of experiencing the composite outcome compared to DOAC patients (OR 1.337, 95% CI 1.212-1.475). Additionally, obese patients were 24.6% more likely to experience the outcome compared to normal BMI patients. Adjusted modeling showed that warfarin patients experienced higher bleed rates compared to DOAC patients (OR 1.432, 95% CI 1.266-1.620). Obese patients were less likely to be diagnosed with a bleed (OR 0.749, 95% CI 0.658-0.854), and underweight patients were more likely to be diagnosed with a bleed (OR 1.522, 95% CI 1.095-2.115) compared to normal BMI patients. In conclusion, DOACs for atrial fibrillation or VTE in patients with extreme body weights appear safe and effective when compared to warfarin.

New Oral Anticoagulants Open New Horizons for Cancer Patients with Venous Thromboembolism

Venous thromboembolism (VTE) is associated with increased morbidity and mortality, decreased quality of life, and higher economic burden in patients with cancer. Currently, the treatment of VTE in patients with cancer is particularly challenging. For many years, low molecular weight heparin (LMWHs) has been the standard for the treatment of cancer-associated VTE. Recently, the introduction of new oral anticoagulants (NOACs) may offer an oral anticoagulant option for some patients with cancer-associated thrombosis (CAT) as a growing body of literature supports the use of NOACs in the setting of CAT. With the use of NOAC as a new option in the management of CAT, clinicians now face several choices for the individual cancer patient with VTE. We need a more in-depth understanding of the drug properties, efficacy and safety, economic analysis that allows us to choose the most appropriate treatment for each patient. In the review, we will present an overview of CAT management, discuss the available evidence, economic costs for NOACs in the treatment of CAT, and seek to provide the best range of treatments for cancer patients.

Direct oral anticoagulants versus low-molecular-weight heparins for the treatment of acute venous thromboembolism in patients with gastrointestinal cancer: a systematic review and meta-analysis

Background

The association between gastrointestinal (GI) cancer and a high incidence of venous thromboembolism (VTE) is well known. Previous randomized controlled studies demonstrated that direct oral anticoagulants (DOACs) effectively treat cancer-associated thrombosis (CAT). However, some DOACs appeared to increase the risk of bleeding, particularly in patients with GI malignancies. Therefore, the current systematic review and meta-analysis were conducted to evaluate the safety and efficacy of DOACs in GI cancer-associated thrombosis.

Methods

Two investigators individually reviewed all studies that compared DOACs and low-molecular-weight heparins (LMWHs) in GI cancer-associated thrombosis and were published in MEDLINE and EMBASE before February 2022. The effect estimates and 95% confidence intervals (CIs) from each eligible study were combined using the Mantel–Haenszel method.

Results

A total of 2226 patients were included in the meta-analysis. The rates of major bleeding in the DOAC and LMWH groups were not significantly different (relative risk [RR]: 1.31; 95% CI: 0.84–2.04; P = 0.23; I² = 41%). However, the rate of clinically relevant nonmajor bleeding (CRNMB) was significantly higher in the DOAC group (RR: 1.76; 95% CI: 1.24–2.52; P = 0.002; I² = 8%). The risks of recurrent VTE in the groups did not significantly differ (RR: 0.72; 95% CI: 0.49–1.04; P = 0.08; I² = 0%).

Conclusions

The current data suggest that treatment of GI cancer-associated thrombosis with DOACs significantly increases the risk of CRNMB. However, the risk of major bleeding was not significantly different. The efficacy of DOACs for preventing recurrent VTE in GI cancer was comparable to that of LMWHs.

Trial registration

INPLASY202180113.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12959-022-00399-7.

Optimal quality of vitamin K antagonist therapy in Japanese patients with venous thromboembolism

BACKGROUND

Vitamin K antagonist (VKA) remains an essential option for venous thromboembolism (VTE), although direct oral anticoagulants have become available. However, there is a paucity of data on the optimal intensity and quality of control for VKA in Japanese.

METHODS

The COMMAND VTE Registry is a multicenter registry enrolling consecutive 3027 patients with acute symptomatic VTE among 29 centers in Japan. The current study population consisted of 1938 patients who received VKA with prothrombin time-international normalized ratio (PT-INR) measurement >5 times. The primary outcome measure was a composite of symptomatic VTE recurrence or major bleeding at 1 year. The presumed optimal quality of VKA therapy was defined as the combination of PT-INR range and time in therapeutic range (TTR) with the numerically lowest event rate.

RESULTS

The group with TTR ≥70 % based on PT-INR range ≥1.5 and <2.0 showed the lowest cumulative incidence rate. The cumulative 1-year incidence and the adjusted risk for the primary outcome measure were significantly lower in the optimal quality group than in the non-optimal quality group (5.2 % vs. 11.7 %, p = 0.001, and HR 0.49, 95%CI 0.28-0.81). Similarly, the cumulative 1-year incidences of a recurrent VTE, major bleeding, and all-cause death were significantly lower in the optimal quality group (recurrent VTE: 2.5 % vs. 6.0 %, p = 0.02; major bleeding: 2.8 % vs. 7.0 %, p = 0.008; and all-cause death: 2.8 % vs. 12.6 %, p < 0.0001). The lower risk of the optimal quality group relative to non-optimal quality group for the clinical outcomes was consistent regardless of the etiology of VTE (active cancer, transient risk factor, and unprovoked).

CONCLUSIONS

The current VTE registry showed the optimal intensity of VKA therapy was target PT-INR range ≥1.5 and <2.0, which could support the current Japanese guideline recommendation, and the good quality of control for VKA therapy of TTR ≥70 % was independently associated with better outcomes.

Portal vein thrombosis in a noncirrhotic patient after hemihepatectomy: A case report and review of literature

BACKGROUND

Portal vein thrombosis (PVT) is a condition caused by hemodynamic disorders. It may be noted in the portal vein system when there is an inflammatory stimulus in the abdominal cavity. However, PVT is rarely reported after hepatectomy. At present, related guidelines and major expert opinions tend to consider vitamin K antagonists or low-molecular weight heparin (LMWH) as the standard treatment. But based on research, direct oral anticoagulants may be more effective and safe for noncirrhotic PVT and are also beneficial by reducing the recurrence rate of PVT.

CASE SUMMARY

A 51-year-old woman without any history of disease felt discomfort in her right upper abdomen for 20 d, with worsening for 7 d. Contrast-enhanced computed tomography (CECT) of the upper abdomen showed right liver intrahepatic cholangiocarcinoma with multiple intrahepatic metastases but not to the left liver. Therefore, she underwent right hepatic and caudate lobectomy. One week after surgery, the patient underwent a CECT scan, due to nausea, vomiting, and abdominal distension. Thrombosis in the left branch and main trunk of the portal vein and near the confluence of the splenic vein was found. After using LMWH for 22 d, CECT showed no filling defect in the portal vein system.

CONCLUSION

Although PVT after hepatectomy is rare, it needs to be prevented during the perioperative period.

Direct oral anticoagulants in patients with chronic thromboembolic pulmonary hypertension and the presence of recent thrombus during pulmonary endarterectomy

Patients with chronic thromboembolic pulmonary hypertension (CTEPH) require lifelong anticoagulant therapy. The safety and efficacy of direct oral anticoagulant (DOAC) in the chronic and transitional management of CTEPH has not been investigated. We performed a retrospective analysis of 405 consecutive pulmonary endarterectomy (PEA) cases at the University of California, San Diego, from July 2015 through July 2017. PEA specimen was reviewed for the presence of acute or subacute thrombotic material distinct from the expected chronic disease removed at the time of PEA by two investigators blinded to the patient information. Of 405 PEA cases, 166 patients (41.0%) were anticoagulated with one of three available DOACs; 239 (59.0%) presented on either oral vitamin‐K antagonist or chronic injectable therapy. There were no significant differences in baseline characteristics between DOAC and non‐DOAC groups. Evidence of recent thrombus was observed in 22 (13.3%) in the DOAC group versus 16 (6.7%) within the non‐DOAC group. The odds ratio of DOACs usage and evidence of recent thrombus was 2.34 (95% confidence interval: 1.1–5.0, p = 0.03) after adjusting for age, gender, race, body mass index, and history of antiphospholipid antibody syndrome. CTEPH patients referred for PEA while on DOAC therapy were twice as likely to have associated acute or subacute thrombi present at the time of surgery compared with those on more traditional, non‐DOAC anticoagulant therapies. This raises questions of the safety and efficacy of DOACs in the chronic management of CTEPH.

Vitamin K antagonist versus novel oral anticoagulants for management of cervical artery dissection: Interactive systematic review and meta-analysis

Purpose:

Cervical artery dissection (CAD) represents a unique clinical entity with a high risk of ischemic stroke. Vitamin K antagonists (VKA) showed good efficacy in CAD management but are cumbersome to use with potentially higher bleeding rates. Novel oral anticoagulants (NOAC) are easier to use and may have similar effects but lower hemorrhagic risk. In this systematic review, we compare the efficacy of NOAC to VKA as a potential alternative treatment.

Methods:

The literature was searched on Pubmed, PMC, and Embase via API through the Nested Knowledge AutoLit software in February 2022 for studies evaluating both NOAC and VKA. Baseline characteristics, clinical and radiographic outcomes, and hemorrhagic and ischemic complications were collected for single and double-arm studies and analyzed using random-effect subgroup meta-analysis.

Findings:

Overall, 11 studies were included with 699 patients treated with VKA and 53 treated with NOAC (from three studies; two were head-to-head comparative studies). There was no statistical difference in the baseline characteristics of VKA and NOAC patients. The rates of TIA/stroke in VKA and NOAC groups were 12.3% (95% CI; 0%, 28.6%) and 5.7% (95% CI; 0%, 12.2%), respectively. Major bleeding or intracranial bleeding were comparable between groups. Lesions treated with VKA showed angiographic recanalization with a rate of 51.4% (95% CI; 35.6%, 67.1%) and for those treated with NOAC was 58.4% (95% CI; 23.9%, 93.9%). The rates of good clinical outcomes were 79.9% (95% CI; 67.6%, 92.2%) in the VKA group and 91.4% (95% CI; 78.1%, 100%) in NOAC. No statistical difference was noted among any of the outcomes between the two treatment groups.

Discussion and conclusion:

We highlighted comparable efficacy and safety of NOAC to VKA for stroke prevention in CAD. Further head-to-head studies are warranted to validate these results.

Thromboembolic Events While Taking Direct Oral Anticoagulants: An Analysis of Post-market WHO Database Reports from 2012 to 2020

BACKGROUND AND OBJECTIVE

Several cases of venous thromboembolism in patients treated with direct oral anticoagulants (DOACs) have been reported in the literature, but a quantative analysis of postmarketing reports is lacking. The objective of this study was to determine the post-marketing odds ratio (OR) and reporting odds ratio (ROR) of venous thromboembolism in patients receiving DOACs compared among each other and to vitamin K antagonists (VKAs).

METHODS

The OR and ROR were used to determine the ratio of reports for deep vein thrombosis and pulmonary embolism between 1 January, 2012 and 15 November, 2020 using the World Health Organization VigiLyze database. This was performed using all venous thromboembolism events in which a DOAC or a VKA was the suspected medication. The OR and ROR including 95% confidence intervals were calculated for each DOAC drug in comparison to all VKAs as a group.

RESULTS

The OR of deep vein thrombosis was highest for rivaroxaban compared with dabigatran and apixaban [2.63 (2.41-2.89); 1.84 (1.72-1.97)]. The OR of deep vein thrombosis was lowest for edoxaban compared with dabigatran, apixaban and rivaroxaban [0.44 (0.32-0.61); 0.31 (0.22-0.42); 0.17 (0.12-0.23)]. The OR of pulmonary embolism was also highest for rivaroxaban compared with dabigatran and apixaban [2.59 (2.37-2.83); 1.79 (1.68-1.92)]. The OR of pulmonary embolism was also lowest for edoxaban compared with dabigatran, apixaban and rivaroxaban [0.77 (0.60-0.97); 0.59 (0.41-0.67); 0.30 (0.23-0.37)]. Comparing RORs of various DOACs with VKAs, rivaroxaban had the highest RORs for deep vein thrombosis/pulmonary embolism, in comparison to apixaban, dabigatran and edoxaban.

CONCLUSIONS

Our findings may indicate a higher association between rivaroxaban therapy and venous thromboembolism as compared with apixaban, dabigatran and edoxaban. These findings are uncertain owing to the reliability of a post-marketing registration system that is negatively influenced by a high level of under-reporting. However, based on pharmacodynamics, we cannot exclude the possibility that there is a real effect that may be driven by non-adherence.

Efficacy and safety of edoxaban in patients with chronic thromboembolic pulmonary hypertension: protocol for a multicentre, randomised, warfarin-controlled, parallel group trial - KABUKI trial

Introduction

Chronic thromboembolic pulmonary hypertension (CTEPH) is a complication of prior pulmonary thromboembolism (PE), caused by incomplete clot dissolution after PE. In patients with CTEPH, lifelong anticoagulation is mandatory to prevent recurrence of PE and secondary in situ thrombus formation. Warfarin, a vitamin K antagonist, is commonly used for anticoagulation in CTEPH based on historical experience and evidence. The anticoagulant activity of warfarin is affected by food and drug interactions, requiring regular monitoring of prothrombin time. The lability of anticoagulant effect often results in haemorrhagic and thromboembolic complications. Thus, lifelong warfarin is a handicap in terms of safety and convenience. Currently, the use of direct oral anticoagulants (DOACs) in CTEPH has increased with the advent of four DOACs. The safety of DOACs is superior to warfarin, with less intracranial bleeding in patients with non-valvular atrial fibrillation and venous thromboembolism. Edoxaban, the latest DOAC, also has proven efficacy and safety for those diseases in two large clinical trials; the ENGAGE-AF trial and HOKUSAI-VTE trial. The present trial seeks to evaluate whether edoxaban is non-inferior to warfarin in preventing worsening of CTEPH.

Methods and analysis

The KABUKI trial (is an investigator-initiated, multicentre, phase 3, randomised, single-blind, parallel-group, warfarin-controlled, non-inferiority trial to evaluate the efficacy and safety of edoxaban versus warfarin (vitamin K Antagonist) in subjects with chronic thromBoembolic pUlmonary hypertension taking warfarin (vitamin K antagonIst) at baseline) is designed to prove the non-inferiority of edoxaban to warfarin in terms of efficacy and safety in patients with CTEPH.

Ethics and dissemination

This study is approved by the Institutional Review Board of each participating institution. The findings will be published in a peer-reviewed journal, including positive, negative and inconclusive results.

Trial registration number

NCT04730037.

Protocol version

This paper was written per the study protocol V.4.0, dated 29 January 2021.

Safety and Efficacy of Direct Oral Anticoagulants in Patients With Moderate to Severe Cirrhosis

BACKGROUND

Direct oral anticoagulants (DOACs) remain mostly investigational in patients with moderate to severe hepatic cirrhosis, yet are often selected over traditional anticoagulants including warfarin and enoxaparin in this setting.

OBJECTIVE

To determine the safety and efficacy of DOACs in patients with moderate to severe hepatic cirrhosis as compared with traditional anticoagulation.

METHODS

This was a retrospective, single-center cohort study evaluating inpatients and outpatients who were prescribed a DOAC, warfarin, or enoxaparin for therapeutic anticoagulation with Child-Turcotte-Pugh (CTP) B or C status at the time that the prescription was written. Included patients were followed until first bleeding or thromboembolic event, or until discontinuation of anticoagulation therapy. Data were collected by manual chart review. The primary outcomes included both bleeding events and thromboembolic events in the DOAC population as compared with traditional anticoagulation.

RESULTS

A total of 101 patients were included in the study, 69 treated with DOAC therapy and 32 with traditional anticoagulation. Bleeding events occurred in 36% of patients in the DOAC group and 22% of patients in the traditional group (P = 0.149). In both groups, bleeds were most commonly gastrointestinal. Thromboembolic events occurred in 4% of the DOAC population and no patients in the traditional population (P = 0.55). No fatal bleeding or thromboembolic events occurred.

CONCLUSION AND RELEVANCE

DOACs do not appear to be more harmful than traditional anticoagulation in patients with CTP B or C status. These results support the use of DOACs in patients with CTP B or C hepatic cirrhosis when considering safety, efficacy, and convenience.

Characteristics and clinical outcomes of Japanese patients with venous thromboembolism receiving under-dose rivaroxaban: subanalysis of J'xactly

OBJECTIVE

Rivaroxaban is commonly prescribed to prevent venous thromboembolism (VTE). Although lower than standard dosages (under-dosing) may be administered in the real-world setting, data on subsequent clinical outcomes in Japanese patients are lacking.

METHODS

The prospective, multicenter, observational J'xactly study enrolled patients with acute symptomatic/asymptomatic deep vein thromboses (DVT), pulmonary embolism (PE), or both, who were prescribed rivaroxaban. This subanalysis investigated patient characteristics and outcomes associated with rivaroxaban under-dosing.

RESULTS

Among 1016 evaluable patients, 667 (65.6%) received an initial standard dosage of rivaroxaban (30 mg/day) and 349 (34.4%) received an initial under-dosage (20 mg/day, n = 22; 15 mg/day, n = 282; and 10 mg/day, n = 45). Those receiving an under-dose had significantly lower body weight and slower pulse rate compared with the standard-dose group regardless of DVT or PE status. Under-dosing was common for distal DVTs, but less frequent for massive/submassive PEs. There were no differences between under-dose and standard-dose groups in the incidences of recurring symptomatic VTEs (DVT: 1.77% vs. 3.35% per patient-year, p = .138; PE: 0.84% vs. 2.84% per patient-year, p = .208) or major bleeding (DVT: 3.55% vs. 3.41% per patient-year, p = .960; PE: not observed vs. 2.83% per patient-year, p = .132).

CONCLUSIONS

In the real-world setting, rivaroxaban under-dosing for patients with VTE occurred in those with lower body weight, slower pulse rate, distal DVT, or non-massive PEs. There were no statistically significant differences in the clinical outcomes for patients received under-dose of rivaroxaban at the discretion of the physicians in the clinical practice compared with those received standard dose of rivaroxaban.

Therapeutic angiogenesis-based strategy for peripheral artery disease

Peripheral artery disease (PAD) poses a great challenge to society, with a growing prevalence in the upcoming years. Patients in the severe stages of PAD are prone to amputation and death, leading to poor quality of life and a great socioeconomic burden. Furthermore, PAD is one of the major complications of diabetic patients, who have higher risk to develop critical limb ischemia, the most severe manifestation of PAD, and thus have a poor prognosis. Hence, there is an urgent need to develop an effective therapeutic strategy to treat this disease. Therapeutic angiogenesis has raised concerns for more than two decades as a potential strategy for treating PAD, especially in patients without option for surgery-based therapies. Since the discovery of gene-based therapy for therapeutic angiogenesis, several approaches have been developed, including cell-, protein-, and small molecule drug-based therapeutic strategies, some of which have progressed into the clinical trial phase. Despite its promising potential, efforts are still needed to improve the efficacy of this strategy, reduce its cost, and promote its worldwide application. In this review, we highlight the current progress of therapeutic angiogenesis and the issues that need to be overcome prior to its clinical application.

Safety and efficacy of Apixaban and Rivaroxaban in obese patients with acute thrombosis/embolism

INTRODUCTION

Direct oral anticoagulants (DOACs) have significant advantages over vitamin K antagonists in the treatment of venous thromboembolism and as prophylaxis against recurrence. However, there is inadequate data to support the safety and efficacy of DOACs in the morbidly obese, and warfarin treatment is currently recommended by the International Society of Hemostasis and Thrombosis for this population.

MATERIALS AND METHODS

We performed a retrospective review of outcomes in 499 patients with BMI ≥ 40 kg/m² admitted from January 2013 to January 2020 with acute venous thromboembolism (VTE) and treated with either rivaroxaban (n=296) or apixaban (n=203).

RESULTS

There were 38 (7.6%) bleeding and clotting events within 60 days of the initiation of DOACs, of which 35 (7.0%) were bleeding events and 3 (0.6%) were clotting events. Patients treated with rivaroxaban had more bleeding episodes (23, 7.8% vs. 12, 5.9%) and higher mortality (21, 7.1% vs. 13, 6.4%) compared with those treated with apixaban; however, these differences were not statistically significant (p=.427 and p=.764, respectively). Most of the bleeding occurred in the genitourinary and gastrointestinal tracts.

CONCLUSIONS

Our study indicates that apixaban and rivaroxaban are not associated with an increase in VTE recurrence in the morbidly obese; however, bleeding rates were slightly higher in the rivaroxaban group compared to the apixaban group.

Extended Anticoagulation After Pulmonary Embolism: A Multicenter Observational Cohort Analysis

Background

Pulmonary embolism (PE) has a long‐term risk of adverse events, which can be prevented by extended anticoagulation. We compared clinical characteristics and outcomes between patients treated with 2‐year extended anticoagulation and those who were not, in a population who had completed an initial phase of 3 to 6 months of anticoagulant therapy after acute PE.

Methods and Results

Observational cohort analysis of patients with PE who survived an initial phase of 3 to 6 months anticoagulation. Primary efficacy outcome was all‐cause death or recurrent venous thromboembolism. Primary safety outcome was major bleeding. In total, 858 (71.5%) patients were treated with and 341 (28.5%) were treated without extended anticoagulant therapy during the active study period. Age <65 years, intermediate‐high or high‐risk index PE, normal platelet count, and the absence of concomitant antiplatelet treatment were independently associated with the prescription of extended anticoagulation. The mean duration of the active phase was 2.1±0.3 years. The adjusted rate of the primary efficacy outcome was 2.1% in the extended group and 7.7% in the nonextended group (P<0.001) for patients treated with extended anticoagulant therapy. Rate of bleeding were similar between the extended anticoagulant group and the nonextended group.

Conclusions

Extended oral anticoagulation over 2 and a half years after index PE seems to provide a net clinical benefit compared with no anticoagulation in patients with PE selected to receive extended anticoagulation. Randomized clinical trials are warranted to explore the potential benefit of extended anticoagulation in patients with PE, especially those with transient provoking factors but residual risk.

Effectiveness and Safety of Nonvitamin K Oral Anticoagulants Rivaroxaban and Apixaban in Patients with Venous Thromboembolism: A Meta-Analysis of Real-World Studies

Background

Rivaroxaban and apixaban are the most widely used nonvitamin K oral anticoagulants (NOACs) in patients with venous thromboembolism (VTE). This meta-analysis evaluates the effectiveness and safety of both NOACs versus standard of care (SoC) in real-world practice.

Methods

Real-world evidence (RWE) studies were identified through a systematic literature review conducted between January 2012 and July 2020, using Embase, MEDLINE, and the websites of cardiological, hematological, and oncological associations. Eligible RWE studies recruited adult patients with deep vein thrombosis and/or pulmonary embolism and presented a comparison between rivaroxaban and apixaban versus SoC, consisting either of vitamin K antagonists, heparins, or combinations thereof. Hazard ratios (HRs) for the comparison between NOACs and SoC were extracted from the relevant studies or estimated based on the reported binary data. The between-treatment contrasts were reported as HRs with associated 95% confidence intervals.

Results

A total of 65 RWE studies were identified and considered relevant for the meta-analysis. Compared with SoC, both rivaroxaban and apixaban were associated with reduced risks of recurrent VTE and a lower rate of major bleeding events. Patients treated with rivaroxaban were at a lower risk of all-cause death compared with those receiving SoC (HR = 0.56 [0.39-0.80]), while evidence for apixaban from the identified studies was insufficient to demonstrate a statistically significant change in mortality (HR = 0.66 [0.30-1.47]).

Conclusion

This analysis indicates that in real-world practice, rivaroxaban and apixaban are associated with a lower risk of recurrent VTE and major bleeding events compared with SoC. Survival benefit in patients treated with rivaroxaban was also observed.

A Review of Direct-acting Oral Anticoagulants and Their Use in Solid Organ Transplantation

Direct-acting oral anticoagulant (DOAC) use has increased dramatically since their introduction because of the growing evidence of proven efficacy and enhanced safety compared with warfarin and the low-molecular-weight heparins in the general population. Unfortunately, there is a dearth of quality data regarding the safety and efficacy of the DOACs in patients awaiting organ transplant and those who received a solid organ transplant. This review aims to evaluate the available literature and considerations regarding anticoagulation use in transplant recipients, focusing on preoperative, perioperative, and postoperative DOAC use.

Morbidly Obese Patients Undergoing Primary Total Joint Arthroplasty May Experience Higher Rates of Venous Thromboembolism When Prescribed Direct Oral Anticoagulants vs Aspirin

BACKGROUND

Morbidly obese (body mass index [BMI] >40 kg/m²) patients undergoing total joint arthroplasty (TJA) are at high risk for postoperative venous thromboembolism (VTE); however, there is debate surrounding the optimal pharmacologic agent for prevention of VTE after TJA in this patient subset. Current guidelines recommend against direct-acting oral anticoagulants (DOACs) in patients of BMI >40 kg/m² due to low quality evidence justifying their use. We evaluated whether patients of BMI >40 kg/m² undergoing primary unilateral TJA would have increased risk of postoperative VTE if prescribed DOACs compared to non-DOAC agents such as aspirin.

METHODS

This retrospective study analyzed 897 patients of BMI >40 kg/m² undergoing primary unilateral TJA. Demographic and comorbidity-related variables were collected. The association between postoperative VTE and prophylactic pharmacologic agent prescribed was evaluated by multivariate logistic regression.

RESULTS

After controlling for comorbidities, we found that the sole use of DOACs, specifically apixaban, for VTE prophylaxis was associated with an increased risk of developing VTE compared to prophylaxis with aspirin alone in patients of BMI >40 kg/m² (odds ratio 2.962, P = .016). Regardless of VTE prophylactic agent, patients with BMI >40 kg/m² undergoing TKA had at least 4.5-fold increased odds of developing VTE compared to patients undergoing THA (OR 4.830, P = .019).

CONCLUSION

In our retrospective study of a large sample size of patients with BMI >40 kg/m², we found that the use of DOACs, specifically apixaban, for VTE prophylaxis following TJA was associated with increased odds of a VTE complication compared to the use of aspirin alone.

Efficacy and Safety Considerations With Dose-Reduced Direct Oral Anticoagulants: A Review

Importance

Dose-reduced regimens of direct oral anticoagulants (DOACs) may be used for 2 main purposes: dose-adjusted treatment intended as full-intensity anticoagulation (eg, for stroke prevention in atrial fibrillation [AF] in patients requiring dose reduction) or low-intensity treatment (eg, extended-duration treatment of venous thromboembolism [VTE]). We reviewed randomized clinical trials (RCTs) to understand the scenarios in which dose-adjusted or low-intensity DOACs were tested and reviewed the labeled indications by regulatory authorities, using data from large registries to assess whether the use of dose-reduced DOACs in routine practice aligned with the findings of RCTs.

Observations

Among 4191 screened publications, 35 RCTs that used dose-adjusted DOACs were identified for dabigatran, apixaban, rivaroxaban, and edoxaban. Of these 35 RCTs, 29 were related to stroke prevention in AF. Efficacy and safety results for dose-adjusted DOACs in large RCTs of AF were similar to those found for full-dose DOACs. To our knowledge, dabigatran, apixaban, and rivaroxaban have not been studied as dose-adjusted therapy for acute VTE treatment. Low-intensity DOACs were identified in 37 RCTs. Low-intensity DOACs may be used for extended-duration treatment of VTE (apixaban and rivaroxaban), primary prevention in orthopedic surgeries (dabigatran, apixaban, and rivaroxaban), primary prevention in ambulatory high-risk cancer patients (apixaban and rivaroxaban) or (postdischarge) high-risk medical patients (rivaroxaban), in stable atherosclerotic vascular disease, or after a recent revascularization for peripheral artery disease in conjunction with aspirin (rivaroxaban). Minor variations exist between regulatory authorities in different regions regarding criteria for dose adjustment of DOACs. Data from large registries indicated that dose-reduced DOACs were used occasionally with doses or for clinical scenarios different from those studied in RCTs or recommended by regulatory authorities.

Conclusions and Relevance

Dose adjustment and low-intensity treatment are 2 different forms of dose-reduced DOACs. Dose adjustment is mostly relevant for AF and should be done based on the approved criteria. Dose adjustment of DOACs should not be used for acute VTE treatment in most cases. In contrast, low-intensity DOACs may be used for primary or secondary VTE prevention for studied and approved indications. Attention should be given to routine practice patterns to align the daily clinical practice with existing evidence of safety and efficacy.

Effect of polypharmacy on bleeding with rivaroxaban versus vitamin K antagonist for treatment of venous thromboembolism

BACKGROUND

Polypharmacy, including use of inhibitors of CYP3A4 and P-glycoprotein (P-gp), is common in patients with venous thromboembolism (VTE) and is associated with increased bleeding.

METHODS

In 8246 patients included in the EINSTEIN-VTE studies for acute VTE, we evaluated the effect of polypharmacy on bleeding and on the relative differences between rivaroxaban and enoxaparin/vitamin K antagonist (VKA). We assessed the incidence of clinically relevant bleeding (major and clinically relevant nonmajor bleeding) by number of comedications (none, 1-3, ≥4) at baseline, and by use of CYP3A4 and/or P-gp inhibitors. Interaction between rivaroxaban versus enoxaparin/VKA and comedication was assessed by Cox regression analysis with pinteraction estimates.

RESULTS

With increasing number of comedications, the incidence of clinically relevant bleeding rose from 5.7% to 13.3% in rivaroxaban recipients and from 9.1% to 11.1% in enoxaparin/VKA recipients. Whereas rivaroxaban was associated with a reduced bleeding risk compared with enoxaparin/VKA in patients without comedication (hazard ratio [HR] 0.6, 95% confidence interval [CI] 0.4-0.9), the risk was similar in patients with ≥4 comedications (HR 1.2, 95% CI 0.97-1.5, pinteraction .002). Use of CYP3A4 and/or P-gp inhibitors was associated with a doubled bleeding risk compared with no use, without a difference between rivaroxaban and enoxaparin/VKA.

CONCLUSION

We conclude that fixed-dose rivaroxaban as compared with enoxaparin followed by dose-adjusted VKA is not associated with an increased bleeding risk in patients with VTE administered polypharmacy in general and CYP3A4 and/or P-gp inhibitors specifically. This implies that the observed increased bleeding risks with polypharmacy and use of CYP3A4 and/or P-gp inhibitors are likely explained by comorbidities and frailty, and not by pharmacokinetic interactions.

Unanswered questions in cancer-associated thrombosis

Cancer-associated venous thromboembolism (VTE) is a leading cause of morbidity and mortality in patients with cancer. Treatment of cancer-associated VTE comes with a heightened risk of anticoagulant-related bleeding that differs by choice of anticoagulant as well as by patient- and disease-specific risk factors. Available data from randomized controlled trials and observational studies in cancer-associated VTE suggest that direct oral anticoagulants are effective, continuing anticoagulation beyond six months is indicated in those with active cancer and that patients who develop 'breakthrough' thrombotic events can be effectively treated. We review the evidence that addresses these key clinical questions and offer pragmatic approaches in individualizing care. While significant investigative efforts over the past decade have made impactful advances, future research is needed to better define the factors that contribute to anticoagulant-related bleeding and VTE recurrence, in order to aid clinical decision-making that improves the care of patients with cancer-associated VTE.

Cutaneous Ulcer Caused by Apixaban Treatment Is Resolved after Replacement with Dabigatran

Nowadays, novel oral anticoagulants (NOACs) have shown improved safety profile and efficacy compared to vitamin K antagonists in the prevention of thromboembolic events occurring during different pathological conditions. However, there are concerns and safety issues, mostly related to adverse events following interactions with other drugs, in real-world practice. We report the case of an 83-year-old woman who developed a non-bleeding leg ulcer not caused by trauma or other evident pathological conditions after 10 days of treatment with apixaban 5 mg/q.d. She was switched from apixaban to dabigatran and the leg ulcer rapidly improved and completely cicatrized in 40 days. The resolution of the ulcer and the toleration of dabigatran therapy suggest an apixaban-specific reaction; however, the pathological mechanism of ulcer onset is currently unclear. Careful evaluation of hospital databases of Molise region (Southern Italy) hospitals identified two similar cases between 2019 and 2021. These cases underline the necessity of careful post-marketing surveillance, considering the rapidly increasing number of patients treated with NOACs and patient’s risk factors such as old age, high polypharmacy rate, co-morbidities, and peculiar genetic background related to NOACs pharmacokinetic features.

Comparative Risks of Fracture Among Direct Oral Anticoagulants and Warfarin: A Systematic Review and Network Meta-Analysis

Importance

Previous studies have shown the effectiveness and safety of direct oral anticoagulants (DOACs), including lower fracture risks, compared to warfarin. However, direct or indirect comparisons between different DOACs are scarce in the literature.

Objective

This study aims to compare fracture risks among different DOACs and warfarin, including apixaban, rivaroxaban, dabigatran, and edoxaban, in patients with non-valvular atrial fibrillation (NVAF) or venous thromboembolism (VTE).

Methods

We searched PubMed/MEDLINE, Embase, Cochrane CENTRAL, and Web of Science for randomized controlled trials and cohort studies comparing the fracture risks among patients who used warfarin or DOACs, up to March 2021. Two authors extracted data and appraised the risk of bias of included studies. The primary outcome was fracture risk. We performed pairwise meta-analyses to compare differences between medications and network meta-analyses using frequentist random-effects models to compare through indirect evidence. We used surface under the cumulative ranking curve (SUCRA) and mean ranks to determine the probability of a DOAC ranking best in terms of fracture risk.

Results

Thirty-one studies were included in the final analysis. Twenty-four randomized controlled trials and seven cohort studies with 455,343 patients were included in the systematic review and network meta-analysis. Compared to warfarin, the risk of any fractures was lowest with apixaban [relative risk (RR) = 0.59; 95% confidence interval (CI): 0.48-0.73], followed by rivaroxaban (RR: 0.72; 95% CI: 0.60-0.86), edoxaban (RR: 0.88; 95% CI: 0.62-1.23), and dabigatran (RR = 0.90; 95% CI: 0.75-1.07). No substantial inconsistency between direct and indirect evidence was detected for all outcomes.

Conclusions

All DOACs were safer than warfarin concerning the risk of fracture; however, apixaban had the lowest relative risk of fracture within the class of DOACs. Further head-to-head prospective studies should confirm the comparative safety profiles of DOACs regarding fractures.

Effectiveness, safety, and healthcare costs associated with rivaroxaban versus warfarin among venous thromboembolism patients with obesity: a real-world study in the United States

Prior observational studies suggest rivaroxaban is safe and effective among patients with morbid obesity who suffered a venous thromboembolism (VTE) event, but existing data are more limited in the broader population of VTE patients with obesity. This study assessed VTE recurrence, major bleeding, healthcare resource utilization, and healthcare costs among VTE patients with obesity who received rivaroxaban versus warfarin. VTE patients with obesity who initiated rivaroxaban or warfarin after a first VTE (index date) were identified from the IQVIA PharMetrics® Plus database (01/02/2011–09/30/2019). The follow-up period spanned from the index date until health plan disenrollment, end of data availability, cancer diagnosis/treatment, end of the 12 month post-index period, or (for the analysis of major bleeding) anticoagulant discontinuation or switch. Patient characteristics were balanced using inverse probability of treatment weighting. The weighted rivaroxaban (N = 8666) and warfarin cohorts (N = 5946) were well balanced (mean age = 51 years, females = 52%). Over a 9.6 months mean observation period, rivaroxaban users had a significantly lower risk of VTE recurrence [7.0% vs. 8.2%, HR(95% CI) = 0.85(0.75;0.97)] and a similar risk of major bleeding [4.1% vs. 3.6%, HR(95% CI) = 1.11(0.89;1.37)] relative to warfarin users at 12 months. Relative to warfarin users, rivaroxaban users had significantly fewer all-cause outpatient visits [RR(95% CI) = 0.71(0.70;0.74)]. The higher pharmacy costs incurred by rivaroxaban recipients (cost difference = $1252) were offset by lower medical costs (cost difference = − $2515, all p < 0.05) compared with warfarin recipients. Our findings suggest that rivaroxaban is safe and effective versus warfarin, and associated with lower medical costs among VTE patients with obesity.

Factor XI Inhibitors for Prevention and Treatment of Venous Thromboembolism: A Review on the Rationale and Update on Current Evidence

Although anticoagulation therapy has evolved from non-specific drugs (i.e., heparins and vitamin K antagonists) to agents that directly target specific coagulation factors (i.e., direct oral anticoagulants, argatroban, fondaparinux), thrombosis remains a leading cause of death worldwide. Direct oral anticoagulants (i.e., factor IIa- and factor Xa-inhibitors) now dominate clinical practice because of their favorable pharmacological profile and ease of use, particularly in venous thromboembolism (VTE) treatment and stroke prevention in atrial fibrillation. However, despite having a better safety profile than vitamin K antagonists, their bleeding risk is not insignificant. This is true for all currently available anticoagulants, and a high bleeding risk is considered a contraindication to anticoagulation. As a result, ongoing research focuses on developing future anticoagulants with an improved safety profile. Several promising approaches to reduce the bleeding risk involve targeting the intrinsic (or contact activation) pathway of coagulation, with the ultimate goal of preventing thrombosis without impairing hemostasis. Based on epidemiological data on hereditary factor deficiencies and preclinical studies factor XI (FXI) emerged as the most promising candidate target. In this review, we highlight unmet clinical needs of anticoagulation therapy, outlay the rationale and evidence for inhibiting FXI, discuss FXI inhibitors in current clinical trials, conduct an exploratory meta-analysis on their efficacy and safety, and provide an outlook on the potential clinical application of these novel anticoagulants.