Novel Anticoagulant Therapy of Venous Thromboembolism: Current Status and Future Directions

Advances in Thromboprophylaxis for High-Risk Pregnancies: A Comprehensive Review of Current Strategies and Emerging Approaches

Thrombosis during pregnancy poses a significant clinical challenge due to its potential for severe maternal and fetal complications. The incidence of thromboembolic events in pregnant women is heightened by pregnancy-associated hypercoagulability, venous stasis, and endothelial changes, all of which contribute to an elevated risk. Effective thromboprophylaxis is essential to mitigate these risks and improve outcomes for both mother and child. This review provides a comprehensive evaluation of current thromboprophylaxis strategies, including pharmacologic interventions such as low-molecular-weight heparins (LMWHs) and unfractionated heparin (UFH) and nonpharmacologic measures like compression stockings and lifestyle modifications. Additionally, the review explores emerging approaches, including personalized medicine strategies, novel anticoagulants, and technology-enabled monitoring solutions. By integrating current evidence with emerging trends, this review aims to offer insights into optimizing thromboprophylaxis in high-risk pregnancies, ultimately contributing to improved clinical outcomes and guiding future research directions in this critical area of maternal healthcare.

Long Non-Coding RNAs in Venous Thromboembolism: Where Do We Stand?

Venous thromboembolism (VTE), a common condition in Western countries, is a cardiovascular disorder that arises due to haemostatic irregularities, which lead to thrombus generation inside veins. Even with successful treatment, the resulting disease spectrum of complications considerably affects the patient's quality of life, potentially leading to death. Cumulative data indicate that long non-coding RNAs (lncRNAs) may have a role in VTE pathogenesis. However, the clinical usefulness of these RNAs as biomarkers and potential therapeutic targets for VTE management is yet unclear. Thus, this article reviewed the emerging evidence on lncRNAs associated with VTE and with the activity of the coagulation system, which has a central role in disease pathogenesis. Until now, ten lncRNAs have been implicated in VTE pathogenesis, among which MALAT1 is the one with more evidence. Meanwhile, five lncRNAs have been reported to affect the expression of TFPI2, an important anticoagulant protein, but none with a described role in VTE development. More investigation in this field is needed as lncRNAs may help dissect VTE pathways, aiding in disease prediction, prevention and treatment.

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.

Safety and efficacy of Direct Oral Anticoagulants in cerebral venous thrombosis: A meta-analysis

Cerebral venous thrombosis (CVT) is caused by partial or complete occlusion of the major cerebral venous sinuses or the smaller feeding cortical veins which predispose to the risk of venous infarction and hemorrhage. Current guidelines recommend treating CVT with either low-molecular-weight heparin (LMWH) or unfractionated heparin (UFH) followed by an oral vitamin K antagonist (VKA) for 3-12 months. Direct oral anticoagulants (DOACs) have already established benefit over warfarin as a long-term treatment of symptomatic venous thromboembolic disorder like deep vein thrombosis (DVT), and pulmonary embolism (PE) given its equal efficacy and better safety profile. The benefit of DOACs over warfarin as a long-term anticoagulation for CVT has likewise been extensively studied, yet it has not been approved as first-line therapy in the current practice. We therefore performed a systematic review and meta-analysis of relevant studies to generate robust evidence regarding the safety and efficacy of DOACs in CVT. This meta-analysis demonstrates that the use of DOACs in CVT has similar efficacy and safety compared to VKAs with better recanalization rate.

Safety and Efficacy of Rivaroxaban for Inferior Vena Cava Thrombosis after Successful Catheter-Directed Thrombolysis

Rivaroxaban use for inferior vena cava (IVC) thrombosis after successful catheter-directed thrombolysis (CDT) is rarely reported. This study aimed at investigating the safety and efficacy of rivaroxaban for IVC thrombosis after CDT. The clinical data on 38 consecutive patients with IVC thrombosis (68% male; mean age, 51.5 ± 16.5), who received rivaroxaban after CDT between July 2017 and January 2020, were retrospectively analyzed in this study. Safety and efficacy of rivaroxaban (bleedings and recurrent venous thromboembolism), cumulative prevalence of post-thrombotic syndrome (PTS), primary patency, clinically driven target lesion revascularization rate, and other adverse events including all-cause mortality and vascular events (systemic embolism, acute coronary syndrome, ischemic stroke, and transient ischemic attack) were retrospectively analyzed. Of the 38 patients who received rivaroxaban for IVC thrombosis after CDT, 27 (71%) had an anticoagulant duration of 6 months and 11 patients (29%) of more than 6 months. Four patients (10%) suffered recurrent thrombosis. No patient suffered major bleeding, while clinically relevant nonmajor bleeding occurred in two (5%) patients. The cumulative prevalence of PTS was 18% (7/38) during the 12 months follow-up period. Primary patency at 1, 3, 6, and 12 months was 97, 92, 90, and 90%, respectively. According to follow-up data, the clinically driven target lesion revascularization of this study was 10%. Cardiovascular events and mortality did not occur in any patient during the study period. Rivaroxaban for IVC thrombosis after successful CDT can be safe and effective.

Venous thromboembolism detected by FDG-PET/CT in cancer patients: a common, yet life-threatening observation

Cancer patients are at markedly increased risk for venous thromboembolism (VTE). Early detection of VTE may decrease morbidity and mortality in this population. We conducted this study to evaluate the ability of FDG-PET/CT to detect thrombosis in cancer patients. This retrospective study included 131 cancer patients with a history of deep vein thrombosis (DVT) or pulmonary embolism (PE) referred for 2-deoxy-2-[¹⁸F]-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT). All subjects underwent PET/CT imaging 60 minutes after FDG injection. Images were visually assessed for increased FDG uptake within the venous lumen. For positive cases, clinical follow-up and Doppler ultrasonography and/or contrast-enhanced CT scans were reviewed. FDG-PET/CT revealed abnormal uptake in the venous system of 26 (19.8%) patients. Eighteen (69.2%) had a history of DVT, and 13 (50%) had a history of PE. The most common site of thrombosis was the inferior vena cava (IVC) (n=14, 53.8%), followed by lower extremities veins (n=9, 34.6%), jugular veins (n=2, 7.7%), and superior vena cava (n=1, 3.8%). The presence of thrombi was confirmed by reviewing clinical follow-up in 6 (23.1%) patients. Among this group, thrombosis was detected in lower extremity veins (n=4, 15.8%), jugular veins (n=1, 3.8%), and IVC (n=1, 3.8%). Our study demonstrates that thrombi prior to their clinical manifestation can be detected by FDG-PET/CT in cancer patients. Moving forward, physicians must carefully consider the venous system when reporting FDG-PET/CT for cancer patients.

Impact of SMTP Targeting Plasminogen and Soluble Epoxide Hydrolase on Thrombolysis, Inflammation, and Ischemic Stroke

Stachybotrys microspora triprenyl phenol (SMTP) is a large family of small molecules derived from the fungus S. microspora. SMTP acts as a zymogen modulator (specifically, plasminogen modulator) that alters plasminogen conformation to enhance its binding to fibrin and subsequent fibrinolysis. Certain SMTP congeners exert anti-inflammatory effects by targeting soluble epoxide hydrolase. SMTP congeners with both plasminogen modulation activity and anti-inflammatory activity ameliorate various aspects of ischemic stroke in rodents and primates. A remarkable feature of SMTP efficacy is the suppression of hemorrhagic transformation, which is exacerbated by conventional thrombolytic treatments. No drug with such properties has been developed yet, and SMTP would be the first to promote thrombolysis but suppress disease-associated bleeding. On the basis of these findings, one SMTP congener is under clinical study and development. This review summarizes the discovery, mechanism of action, pharmacological activities, and development of SMTP.

Administration of Direct Oral Anticoagulant Immediately after Unfractionated Heparin Bolus for the Treatment of Intermediate-High-Risk Pulmonary Thromboembolism

Objective: This study aims to evaluate the efficacy and safety of direct oral anticoagulants (DOACs) after unfractionated heparin (UFH) bolus for the treatment of intermediate-high-risk pulmonary embolism. Materials and Methods: On the basis of initial treatment, 81 patients were divided into two groups: DOAC after UFH bolus infusion group (group D; n=32) and conventional therapy group (group C; n=49). The frequency of recurrence of venous thromboembolism (VTE) and bleeding within 6 months were compared. In addition, hospitalization length and thrombus reduction rate in the pulmonary artery on computed tomography (CT) at the chronic phase were assessed. Results: Recurrence of VTE was found in one (3.1%) and three patients (6.1%) (P=1.00) in groups D and C, respectively, whereas no bleeding events was found in group D and 8.2% of patients in group C (P=0.15). Group D showed shorter hospitalization (7.2±2.3 days) than group C (15.7±9.9 days; P<0.001). In the subset of patients with serial CT assessment (group D, n=20; group C, n=38), almost all thrombus of pulmonary artery were disappeared and the thrombus reduction rates were similar between the two groups (group D, 99.5%; group C, 97.1%; P=0.59). Conclusion: DOAC administration immediately after UFH bolus treatment has the same efficacy and safety, whereas hospitalization days were significantly shorter than the conventional treatment group.

Feline aortic thromboembolism: Presentation, diagnosis, and treatment outcomes of 15 cats

Background

Feline aortic thromboembolism (FATE) is a fatal disease where a blood clot gets lodged into the aortic trifurcation.

Methods

Fifteen cats with a sudden onset of hind limb paresis/paralysis, vocalization, and pain were admitted to the surgery clinic. A full case history was obtained and clinical, orthopedic, neurologic, radiographic, electrocardiographic, and echocardiographic examinations were performed for each cat. The treatment protocol included daily administration of multiple anticoagulant drugs with different mode of actions and meloxicam for 7 successive days. Prophylactic anticoagulant therapy (clopidogrel and acetylsalicylic acid) was continued for 6 months. All data were statistically analyzed and the correlation between time of admission and treatment outcome was tested using Pearson's correlation coefficient.

Results

The case history and clinical, orthopedic, and neurologic examinations revealed a sudden onset of hind limb paralysis (n = 12) or paresis (n = 3) associated with vocalization and pain, absence of trauma, cold and pale paws of hind limbs (n = 13, 86.7%) or cyanosed hind paws (n = 2, 13.3%), absence of femoral pulsation, shallow and rapid open-mouth respiration (61 ± 8 breaths/minutes), hypothermia (37.9°C ± 0.6°C) and tachycardia (155 ± 12 beats/minutes), with a muffled heart sound in four cats (26.7%). Radiography revealed no abnormalities in the hind limbs, pelvis, and spines, cardiomegaly in five cats (33.3%), mild pleural effusion and vascular pattern of the lung in six cats (40%), and Valentine's heart shape in four cats (26.7%). Electrocardiography (ECG) revealed an R-wave< 0.9 mV, prolongation of QRS interval in five cats (33.3%), and conduction disturbance in four cats (26.7%). Echocardiography was consistent with hypertrophic cardiomyopathy (HCM) in five cats (33.3%). A statistically significant (p= 0.023) strong negative correlation (r= -0.6) was reported between time of admission and subsequent early treatment and recovery from clinical signs. The treatment was successful in nine cats (60%), while four cats (26.7) were euthanized and two cats (13.3%) were subjected to hind limb amputation, at the owners' requests.

Conclusion

Clinical signs, radiography, ECG, and echocardiography are valuable for diagnosis of FATE. The outcome of the multiple anticoagulants therapy depends mainly upon early diagnosis and treatment within the first 6 hours from the onset of clinical signs.

Clinical Trial Based Rationale for the Successful Use of DOAC in the Treatment of Cerebral Venous Sinus Thrombosis (CVST): A Case Report

In cerebral venous sinus thrombosis (CVST), venous sinus occlusion increases venous pressure and disrupts venous return, resulting in progression to venous infarction and venous hemorrhage, with poor neurologic outcome. Therefore, early recanalization of the major venous sinus is critical. Anticoagulant therapy with continuous intravenous infusion of heparin and subsequent oral anticoagulant administration is the recommended first line of treatment for CVST. Some large clinical trials for venous thromboembolism (VTE) have shown that direct oral anticoagulant (DOAC) is non-inferior to the standard therapy with heparin or warfarin and causes less bleeding. In contrast, there are only a few reports on CVST treatment with DOAC such as Dabigatran, Rivaroxaban and Edoxaban describing good efficacy and safety. And there is one randomized clinical trial on DOAC treatment for CVST after acute phase. We report a successfully treated case of CVST in acute phase with progressive neurologic symptoms that achieved early recanalization of the obstructed sinus by an early switch from continuous intravenous infusion of heparin to oral Edoxaban.

Use of rivaroxaban in patients attending a hematology unit in clinical practice

Aim: To determine drug persistence and rates of events among patients treated with rivaroxaban in a hematology unit. Methods: Retrospective study of patients that started treatment with rivaroxaban, in the hematology unit of a tertiary hospital. Results: A total of 161 patients were included, of whom 83.9% had atrial fibrillation and 11.2% venous thromboembolism, and 76.4% of patients were taking rivaroxaban 20 mg, 22.4% 15 mg and 1.2% 10 mg. After a follow-up of 1.8 ± 1.1 years, only four patients (2.5%) discontinued treatment. Rates of thromboembolic events, major bleeding/clinically relevant nonmajor bleeding and intracranial hemorrhage were 1.1, 2.8, 0.3 events per 100 patient-years, respectively. Conclusion: In patients attended in a hematology unit, medication persistence was high, and the incidence of outcomes low.

Rivaroxaban for the treatment of venous thromboembolism in real life: A single-center prospective study

The clinical profile, evolution and complications of treatment with rivaroxaban in a cohort of patients presenting with venous thromboembolism (VTE) were analyzed in an observational, non-interventional and prospective study.A total of 111 patients were included in the study. Clinical data were collected from the medical history of the patients and recorded in a specific database.Mean age was 63.8 ± 17.4 years, 53.2% of patients were men, 55.9% had at least another concomitant condition, and 40.9% at least 1 VTE risk factor. 54.1% of patients presented with deep venous thrombosis, 32.4% with pulmonary embolism and 13.5% with both conditions simultaneously. The 61% of patients were admitted to hospital and mean hospital length-of-stay was 8.8 ± 9.9 days. After a mean follow-up 530 ± 464 days (median follow-up of 405 days), 3.9% of patients died and VTE recurrence occurred in 2.9% of patients. While receiving rivaroxaban, a first bleeding complication occurred in 8.1%; all events were minor bleeding.Our study supports the current literature data and confirms the similar results of real-life VTE patients with those enrolled in the rivaroxaban pivotal clinical trials. Rivaroxaban may facilitate outpatient treatment and might be considered as a first-line therapy for the management of VTE patients.

Hospital Resource Utilization and Costs Associated With Warfarin Versus Apixaban Treatment Among Patients Hospitalized for Venous Thromboembolism in the United States

A real-world US database analysis was conducted to evaluate the hospital resource utilization and costs of patients hospitalized for venous thromboembolism (VTE) treated with warfarin versus apixaban. Additionally, 1-month readmissions were evaluated. Of 28 612 patients with VTE identified from the Premier Hospital database (August 2014-May 2016), 91% (N = 26 088) received warfarin and 9% (N = 2524) received apixaban. Outcomes were assessed after controlling for key patient/hospital characteristics. For index hospitalizations, the average length of stay (LOS) was longer (3.8 vs 3.1 days, P < .001; difference: 0.7 days) and mean hospitalization cost higher (US$3224 vs US$2,740, P < .001; difference: US$484) for warfarin versus apixaban-treated patients. During the 1-month follow-up period, warfarin treatment was associated with a greater risk of all-cause readmission (odds ratio [OR]: 1.27; 95% confidence interval [CI]: 1.09-1.48, P = .003), major bleeding (MB)-related readmission (OR: 2.10; 95% CI: 1.03-4.27, P = .04), and any bleeding-related readmission (OR: 1.67; 95% CI: 1.09-2.56, P = .02) versus apixaban. The results of this real-world analysis show that compared to warfarin, apixaban treatment was associated with shorter index hospital stays, lower index hospitalization costs, and reduced risk of MB-related readmissions among hospitalized patients with VTE.

Treatment Outcomes of Anticoagulant Therapy and Temporary Inferior Vena Cava Filter Implantation for Pregnancy Complicated by Venous Thrombosis

Objective: Although deep vein thrombosis (DVT) followed by pulmonary thromboembolism (PE) is a critical complication during pregnancy, there have been few reports about its intrapartum management. We evaluated intrapartum management by using a temporary inferior vena cava filter (IVCF) in pregnant women with PE/DVT.

Materials and Methods: Eleven women with PE/DVT during pregnancy between January 2004 and December 2016 were included. The patients were hospitalized for intravenous unfractionated heparin infusion after acute PE/DVT onset. Seven patients were discharged and continued treatment with subcutaneous injection of heparin at the outpatient unit. IVCF was implanted 1–3 days before delivery in 10 patients. Anticoagulant therapy was discontinued 6–12 h before delivery. We retrospectively analyzed rates of maternal or perinatal death, and recurrence of symptomatic PE/DVT.

Results: One patient was diagnosed as having PE/DVT and 10 had DVT alone. One patient suffered hemorrhagic shock during delivery; however, maternal or perinatal death and recurrence of symptomatic PE/DVT did not occur in any patient.

Conclusion: Maternal or perinatal death and recurrence of symptomatic PE/DVT was not seen in women diagnosed as having PE/DVT during pregnancy and treated with anticoagulant therapy and IVCF.

Great Saphenous Vein Flow Pattern as a Simple Ultrasonographic Sign of Early Recanalization of Deep Vein Thrombosis: A Case Series Report

We retrospectively examined patients with ultrasonographically occlusive acute proximal deep vein thrombosis (DVT). All patients were categorized into two groups on the basis of whether great saphenous vein (GSV) flow toward the common femoral vein was detected (flow [+]; n=10) or undetected (flow [−]; n=10). We investigated the relationship between the GSV flow pattern and DVT recanalization. Thrombus recanalization, which is defined as diameter reduction to lower than 40% of the vessel diameter, was confirmed in seven of the flow (+), and none of the flow (−). This study proposes that the GSV flow pattern may be a simple marker for the recanalization of proximal occlusive DVT.

Assessment of the Safety and Efficacy of Edoxaban for the Treatment of Venous Thromboembolism Secondary to Active Malignancy

Objective: To assess the safety and efficacy of edoxaban for the treatment of venous thromboembolism (VTE) secondary to active malignancy.

Materials and Methods: We enrolled 48 patients with newly diagnosed VTE secondary to active malignancy that was treated with oral edoxaban for 1 year between September 2014 and August 2015. We retrospectively examined the presence or absence of recurrent symptomatic VTE, VTE-related mortality, and bleeding events.

Results: No recurrent symptomatic VTE or VTE-related deaths were recorded, enabling efficient assessment. Treatment safety was determined based on the reports of bleeding. Bleeding was reported in two patients, with serious bleeding in one of them.

Conclusion: Edoxaban is safe and effective for the treatment of VTE secondary to active malignancy.