Clinical Outcomes of Direct Oral Anticoagulants vs Warfarin for Extended Treatment of Venous Thromboembolism

The effect of anticoagulation therapy on the surgical outcomes of minimally invasive major gastrointestinal surgery

BACKGROUND

The surgical outcomes of minimally invasive surgery (MIS) for gastrointestinal (GI) cancers in patients receiving anticoagulation therapy (ACT) are unknown. We investigated the effect of ACT on the surgical outcomes of minimally invasive major GI surgery, with a particular focus on postoperative bleeding and thromboembolic complications.

METHODS

A total of consecutive 1290 patients undergoing elective minimally invasive (laparoscopic and robotic) major GI surgery (esophagogastric and colorectal resection for malignancy) between 2014 and 2023 were enrolled. The patients were divided into three groups: patients without receiving anticoagulation therapy (non-ACT, n = 1076), patients receiving direct oral anticoagulants (DOAC, n = 144), and patients receiving warfarin (WF, n = 70). Outcome variables were compared between the groups and the risk factors of postoperative bleeding complications were assessed using logistic multivariate analysis.

RESULTS

The overall rate of thromboembolic complication was 0.5%, and the operative mortality was zero in the whole cohort. The incidences of postoperative bleeding in the non-ACT, DOAC, and WF groups were 1.0%, 6.9% and 11.4%, respectively (P < 0.001). Among 8 DOAC-received patients with postoperative GI bleeding, 75% of cases occurred on postoperative day 5 or later. Multivariate analysis showed DOAC (odds ratio = 5.420, P < 0.001) and perioperative heparinization (odds ratio = 3.770, P = 0.048) were significant risk factors for major postoperative bleeding.

CONCLUSIONS

Although minimally invasive major GI surgery can be safely performed in patients receiving ACT, attention should be paid for the occurrence of delayed GI bleeding especially in the DOAC-received patients. Patients treated with DOAC or perioperative heparinization still represent a challenging group in the present cohort, and need to be carefully managed.

Real-world safety profile of direct oral anticoagulants (DOACs): Disproportionality analysis of major bleeding events

BACKGROUND

Direct Oral Anticoagulants (DOACs) have revolutionized the management of thrombotic conditions, providing more predictable and manageable anticoagulation compared to traditional vitamin K antagonists. Despite their success, major bleeding events remain a significant concern. This study aims to assess and compare the haemorrhagic risks associated with various DOACs using data from the FDA's Adverse Event Reporting System (FAERS).

METHODS

A retrospective disproportionality analysis of the FAERS database was conducted, covering the period from January 1, 2015, to December 31, 2023. The study focused on adverse bleeding events reported for DOACs. The Proportional Reporting Ratio (PRR) was calculated for each DOAC to identify disproportionate reporting of haemorrhagic events. Major haemorrhagic events were classified as those leading to hospitalization. The analysis also utilized the Medicare Part D dataset to estimate the usage of specific DOACs from 2015 to 2021.

RESULTS

A total of 353,188 haemorrhagic events were identified, with 17,236 (4.9%) attributed to DOACs. The PRR for major haemorrhagic events was highest for Edoxaban at 14.1 (95% CI 13.93-14.85), followed by Dabigatran at 4.0 (95% CI 3.81-4.20), Apixaban at 3.53 (95% CI 3.47-3.61), and Rivaroxaban at 2.11 (95% CI 2.05-2.18). Edoxaban also had the highest PRR for cerebral haemorrhages. Medicare data indicated that Apixaban was the most commonly used DOAC (58.3%), followed by Rivaroxaban (34.5%).

CONCLUSIONS

Edoxaban shows a significantly higher risk of major and cerebral haemorrhages compared to other DOACs, while Rivaroxaban demonstrates a lower overall risk of haemorrhage. These findings emphasize the need for careful consideration of bleeding risks in DOAC therapy. Continuous post-marketing surveillance is crucial for understanding the safety profiles of DOACs in real-world clinical settings, aiding clinicians and patients in making informed decisions about anticoagulant therapy.

Milvexian: An Oral, Bioavailable Factor XIa Inhibitor

Direct oral anticoagulants have a dose-dependent increased bleeding risk which limits use in certain populations. Studies in both animals and humans with inherited variations in factor XI levels provide a theoretical basis for a drug target capable of addressing current unmet needs. Milvexian is an oral factor XIa inhibitor that has the potential to provide robust anticoagulant effect without increased bleeding compared with current standard of care. Several key studies in the preclinical, phase I, and phase II stages have reported promising safety data in venous thromboembolism and stroke prevention without compromising hemostasis. The planned phase III trials will examine the efficacy of milvexian for prevention of thrombotic events in patients with acute stroke, acute coronary syndrome, and atrial fibrillation.

Apixaban removal during emergency surgery for type A acute aortic dissection: a prospective cohort study

BACKGROUND

Acute type A aortic dissection (ATAAD) has a high mortality, and acute aortic repair is the only curative treatment. In patients treated with factor Xa (FXa) inhibitors, the risk of severe disease-related complications such as cardiac tamponade and hemodynamic shock must be balanced against the potential for severe perioperative bleeding. The aim was to study intraoperative changes in plasma levels of the FXa inhibitor apixaban when using hemoadsorption during acute thoracic aortic repair.

MATERIALS AND METHODS

This is a single-center prospective cohort study. Eight apixaban-treated patients presenting with ATAAD underwent acute thoracic aortic repair with intraoperative hemoadsorption with CytoSorb. Apixaban concentrations were measured at the start of cardiopulmonary bypass (CPB) and after 5, 15, 30, 60, and 90 min of CPB, at CPB weaning, 30 min after CPB weaning and 24 h postoperatively, using ultraperformance liquid chromatography-mass spectrometry (UPLC-MS).

RESULTS

After 30 min of CPB with hemoadsorption, mean apixaban concentration (±SD) was reduced by 59% from 108 (±69) µg/l to 44 (±20) µg/l (P=0.009). There was a further reduction to 37 (±17) µg/l at CPB weaning (P=0.008). Apixaban concentration displayed an increase to 56 (±29) µg/l 24 h postoperatively (P=0.01). In-hospital mortality was 25%. The mean 24H chest tube drainage volume was 621 (±136) ml.

CONCLUSION

Intraoperative hemoadsorption lowers apixaban levels in patients undergoing emergency surgery for ATAAD. Further research is needed to determine its impact on perioperative bleeding complications and mortality.

Regulation of macrophage fibrinolysis during venous thrombus resolution

BACKGROUND

Venous thromboembolism (VTE), which includes pulmonary embolism (PE) and deep vein thrombosis (DVT), is a serious cardiovascular disease with significant mortality and morbidity. Clinically, patients with faster resolution of a venous thrombi have improved prognosis. Urokinase-plasminogen activator (uPA), produced by macrophages, is a key mediator of fibrinolysis required for resolving venous thrombi and restoring vascular integrity. The major macrophage protein, plasminogen activator inhibitor type-2 (PAI-2), was originally identified as an inhibitor of uPA and is implicated in the modulation of pathways affecting fibrinolytic uPA activity, however its direct role in blocking uPA-mediated clot lysis is not known.

OBJECTIVE

To determine the contribution of macrophage PAI-2 in inhibiting uPA-mediated fibrinolysis during resolution of DVT.

METHODS

Using a murine model of venous thrombosis and resolution, we determined histological changes and molecular features of fibrin degradation in venous thrombi from WT mice and mice genetically deficient in PAI-2 and PAI-1, and determined the fibrinolytic activities of macrophages from these genotypes ex vivo.

RESULTS

Acceleration of venous thrombus resolution by PAI-2-/- mice increases fibrin degradation in venous thrombi showing a pattern similar to genetic deficiency of PAI-1, the major attenuator of fibrinolysis. PAI-2 deficiency was not associated with increased macrophage infiltration into thrombi or changes in macrophage PAI-1 expression. uPA-initiated fibrinolysis by macrophages in vitro could be accelerated by PAI-1 deficiency, but not PAI-2 deficiency.

CONCLUSION

PAI-2 has an alternate anti-fibrinolytic activity that is macrophage uPA independent, where PAI-1 is the dominant uPA inhibitor during DVT resolution.

Tailoring oral anticoagulant treatment in the era of multi-drug therapies for PAH and CTEPH

The use of oral anticoagulants in the management of pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) presents distinct therapeutic challenges and benefits. In PAH, the benefits of oral anticoagulation are uncertain, with studies yielding mixed results on their efficacy and safety. Conversely, oral anticoagulants are a cornerstone in the treatment of CTEPH, where their use is consistently recommended to prevent recurrent thromboembolic events. The choice between vitamin K antagonists (VKAs) and direct oral anticoagulants (DOACs) remains a significant clinical question, as each type presents advantages and potential drawbacks. Furthermore, drug-drug interactions (DDIs) with concomitant PAH and CTEPH treatments complicate anticoagulant management, necessitating careful consideration of individual patient regimens. This review examines the current evidence on oral anticoagulant use in PAH and CTEPH and discusses the implications of DDIs within a context of multi-drug treatments, including targeted drugs in PAH.

Safety and Effectiveness of Direct Oral Anticoagulants Versus Warfarin in Patients with Venous Thromboembolism using Real-World Data: A Systematic Review and Meta-Analysis

BACKGROUND

Direct oral anticoagulants (DOACs) have shown comparable efficacy and a superior safety profile in clinical trials for patients with venous thromboembolism (VTE). However, further study is needed to assess DOACs' effectiveness and safety compared to warfarin in a real-world context. Thus, this meta-analysis compares the effectiveness and safety of warfarin and DOACs in patients with VTE.

METHOD

A systematic review of the literature using PubMed and EMBASE was conducted from inception until June 2024. We examined observational studies that compared safety and effectiveness between DOACs and warfarin when used in treating VTE and reported adjusted hazard ratios (HRs) and/or odds ratios (ORs) for recurrent VTE, major bleeding, clinically relevant non-major bleeding, gastrointestinal bleeding, intracranial hemorrhage, and death from any cause. We then estimated the pooled effect using the random-effects model for meta-analysis.

RESULTS

A total of 25 studies were included in the current meta-analysis. DOAC therapy was associated with significantly lower risks of recurrent VTE (HR 0.76, 95% confidence interval [CI] 0.69-0.85), major bleeding (HR 0.77, 95% CI 0.72-0.83), clinically relevant non-major bleeding (HR 0.82, 95% CI 0.77-0.88), and gastrointestinal bleeding (HR 0.75, 95% CI 0.68-0.83) compared to warfarin. However, no statistically significant difference was observed in all-cause mortality between the two groups (HR 0.96, 95% CI 0.83-1.10).

CONCLUSION

This meta-analysis found that DOACs are associated with a significant reduction in VTE recurrence in addition to the known favorable safety profile when compared to warfarin.

Comparing the Effect of DOAC-Stop® and DOAC-Remove® on Apixaban, Rivaroxaban and Dabigatran Prior to Thrombophilia and Lupus Testing

Background

Direct oral anticoagulants (DOACs) interfere with coagulation assays potentially leading to inaccurate results. This study determined the effectiveness of DOAC-stop® and DOAC-remove® in overcoming DOAC interference. It aimed to investigate the extent to which apixaban, rivaroxaban, and dabigatran had an effect on thrombophilia and lupus tests using normal plasma, as well as whether DOACs interfere with true-positive results by testing abnormal controls.

Methods

Apixaban (0.03 mg/mL), rivaroxaban (0.01 mg/mL), and dabigatran (0.019 mg/mL) stock solutions were made and added to the normal pool at three different concentrations (200, 400 and 600 ng/mL) and to the abnormal controls at a single concentration. These samples and untreated DOAC controls were tested before and after adding either DOAC-stop® or DOAC-remove®. The measured parameters included protein C, protein S, antithrombin III (ATIII), DRVVS, DRVVC, PTT-LA and DOAC concentration. The normal pool spiked with DOAC was repeated seven times for each DOAC at each concentration level and the abnormal controls spiked with DOAC were repeated four times at a single concentration level for each DOAC.

Results

In the normal pool, dabigatran and rivaroxaban affected all lupus anticoagulant tests, whereas apixaban only affected DRVVS and DRVVC. While dabigatran led to false-positive protein S deficiency and falsely elevated ATIII. Both DOAC-stop® and DOAC-remove® brought the thrombophilia results and all falsely elevated lupus anticoagulant results back within the normal range for apixaban and rivaroxaban. For dabigatran all the affected lupus anticoagulant tests remained abnormal following DOAC-remove®, unlike DOAC-stop® treatment, where only DRVVS and DRVVC at 600 ng/mL remained abnormal. In abnormal controls, all DOACs falsely elevated the lupus anticoagulant tests, whereas dabigatran caused false negative ATIII results, that were corrected (remained abnormal) with DOAC-stop® and DOAC-remove®. DOAC-stop® showed a greater reduction in lupus anticoagulant results than DOAC-remove®, causing a false-negative DRVVT ratio for rivaroxaban.

Conclusion

DOAC-stop® is more effective than DOAC-remove® in removing all DOACs below the reference range, whereas DOAC-remove® failed to remove dabigatran.

Management and Outcomes of Pulmonary Embolism in the Oldest-Old

Background

Treatment for pulmonary embolism has expanded to include Direct Oral Anticoagulants (DOACs). The incidence of pulmonary-embolism (PE) in "oldest-old" age group (≥85 years) is rapidly increasing, but there is limited research on its management and clinical outcomes.

Aim

To examine the differences in management and outcomes in those aged ≥85 years compared to other age groups.

Methods

We performed a retrospective cohort-study of 373 consecutive patients with pulmonary embolism confirmed on imaging by Computed Tomography Pulmonary Angiogram (CTPA) or Ventilation Perfusion (VQ) Scan at a principal referral hospital in Sydney, Australia. Data collected include clinical and demographic data, Charlson comorbidity index, treatment type and outcomes including complications, recurrent venous thromboembolism, and mortality.

Results

Across the age groups, DOACS were prescribed to 53.4% (n=199) of patients. In oldest-old patients with PE, LMWH bridging to warfarin was the most frequently prescribed treatment, used in 46.2% (n=18, 95% CI: 30.8%-61.5%, p=0.003) of these patients. The mortality rate for patients on LMWH was 13.9% (n=5, 95% CI: 4.2%-37.5%, p=0.553). Overall, major bleeding incidents were rare, occurring in just 1.7% (n=4, 95% CI: 0.4%-3.3%) of patients, with no significant differences in outcomes across age groups.

Conclusion

DOACs are increasingly used as the treatment modality of choice in atrial fibrillation but are less well studied in pulmonary embolism, particularly in oldest-old patients. We found that the safety and efficacy profile of DOACs in pulmonary embolism treatment is similar across the age groups. Our study does not support any change in treatment protocols of PE in the oldest old, but further studies are required to confirm our findings.

Arg-Specific serine Protease-Targeted edoxaban tosylate monohydrate-Poly (lactic-co-glycolic acid) Nanoparticles: Investigating Stuart-Prower factor targeting and intestinal distribution through Ex-Vivo fluorescent visualization

The goal of the current study was to formulate and examine the potential of poly (lactic-co-glycolic acid) (PLGA) as carriers to facilitate the targeted administration of edoxaban tosylate monohydrate (ETM). ETM-PLGA-NPs were effectively formulated using the nanoprecipitation technique. Particle size, drug entrapment percentage, zeta potential, assessment of intestinal absorption, FT-IR, SEM, drug dissolution behavior, and histopathology investigations were used to describe ETM-PLGA-NPs. The produced NPs had a roughly spherical shape with a particle size of 99.85 d.nm, a PDI of 0.478, and a zeta potential of 38.5 mV with a maximum drug entrapment of 82.1 %. FTIR measurements showed that the drug's chemical stability remained intact after preapred into nanoparticles. In vitro drug release behavior followed the Higuchi model and revealed an early burst release of 30 % and persistent drug release of 78 % from optimized NPs for up to 120 hrs. According to in vitro data, a 1:10 ratio of ETM to PLGA provided longer-lasting ETM release and improved encapsulation efficiency. Images captured with an inverted fluorescent microscope exhibited that NPs may both greatly increase the amount of ETM accumulated in the intestinal tract and make it easier for ETM to enter the membrane beneath the cells of the intestines. The study found that using PLGA nanoparticles to encapsulate the ETM resulted in longer circulation duration (aPTT, PT, TT). In vivo investigations found that nanoparticles encapsulated had no negative impact on hematological parameters, lung, liver, or kidney tissues. All things considered, the NPs are a potential delivery method to increase the oral absorption and antithrombotic activity of ETM.

Temporal Changes in Long-Term Outcomes of Venous Thromboembolism From the Warfarin Era to the Direct Oral Anticoagulant Era

BACKGROUND

There have been limited data on the changes in clinical outcomes after the introduction of direct oral anticoagulants (DOACs) for venous thromboembolism (VTE) in real clinical practice. We evaluated the changes in management strategies and long-term outcomes from the warfarin era to the DOAC era.

METHODS AND RESULTS

We compared the 2 series of multicenter COMMAND VTE (Contemporary Management and Outcomes in Patients With Venous Thromboembolism) registries in Japan enrolling consecutive patients with acute symptomatic VTE: Registry 1: 3027 patients in the warfarin era (2010-2014) and Registry 2: 5197 patients in the DOAC era (2015-2020). The prevalence of DOAC use increased more in Registry 2 than in the Registry 1 (Registry 1: 2.6% versus Registry 2: 79%, P<0.001). The cumulative 5-year incidence of recurrent VTE was significantly lower in Registry 2 than in Registry 1 (10.5% versus 9.5%, P=0.02), and the risk reduction of recurrent VTE in Registry 2 remained significant even after adjusting the confounders (hazard ratio [HR], 0.78 [95% CI, 0.65-0.93]; P=0.005). The cumulative 5-year incidence of major bleeding was not significantly different between the 2 registries (12.1% versus 13.7%, P=0.26), and the risk of major bleeding between the 2 registries was not significantly different even after adjusting the confounders (HR, 1.04 [95% CI, 0.89-1.21]; P=0.63).

CONCLUSIONS

Along with the shift from warfarin to DOACs, there was a lower risk of recurrent VTE in the DOAC era than in the warfarin era, whereas there was no apparent change in the risk of major bleeding, which might still be an unmet need even in the DOAC era.

Efficacy and Safety of Direct Oral Anticoagulants for Acute Treatment of Venous Thromboembolism in Older Adults: A Network Meta-Analysis of Randomised Controlled Trials

OBJECTIVE

This systematic review and network meta-analysis aimed to evaluate the efficacy and safety of direct oral anticoagulants (DOACs) in adults aged 75 and over undergoing acute venous thromboembolism (VTE) treatment.

METHODS

PubMed, Embase and the CENTRAL were searched up to 25 December 2023. The incidence of VTE recurrence and bleeding events was assessed. Employing a frequentist network meta-analysis approach, interventions not directly compared could be indirectly assessed through the 95% confidence interval (CI), enhancing the interpretability of the search results. The surface under the cumulative ranking curves (SUCRA) was utilized to generate the relative ranking probabilities for each group.

RESULTS

Our study, analysing 6 randomised controlled trials with 3665 patients, compares direct oral anticoagulants (DOACs) and vitamin K antagonists (VKAs) in adults aged 75 and over with acute venous thromboembolism. Edoxaban reduces VTE recurrence risk compared with VKAs (risk ratio [RR] .50, 95% CI 0.27 - .95), while apixaban significantly decreases bleeding risk compared with VKAs (RR .23, 95% CI 0.08 - .69), edoxaban (RR .28, 95% CI 0.09 - .86) and rivaroxaban (RR .28, 95% CI 0.09 - .86). Despite low overall evidence quality, apixaban consistently ranks highest for both efficacy and safety. Findings underscore the nuanced efficacy-safety balance in this population, emphasizing cautious interpretation due to evidence limitations.

CONCLUSION

Apixaban emerges as a favourable choice for acute VTE treatment in the elderly, displaying reduced bleeding risk compared to other treatments while maintaining comparable efficacy. Future studies should explore diverse anticoagulants efficacy and safety in older populations. Additionally, clinical prediction models tailored to geriatric cohorts are crucial for guiding treatment duration decisions.

Factor V Leiden Heterozygous: Complicated by Recurrent Venous Thromboembolism and Bilateral Pulmonary Embolism

Factor V Leiden (FVL) is a hypercoagulable disorder that puts patients at increased risk of initial venous thromboembolism (VTE). However, those with heterozygote status are not usually susceptible to recurrent VTE. This is a case of a 35-year-old Caucasian male who presented to the emergency department with shortness of breath and chest pain. He had a past medical history of superficial thrombophlebitis and deep vein thrombosis (DVT) and was known to be FVL heterozygous. His home medications did not include anticoagulation medications at the time of presentation to the emergency department. The patient was diagnosed with bilateral pulmonary embolisms (PEs) secondary to a recurrent DVT. Initial treatment included a pulmonary thrombectomy and a lower extremity thrombectomy. Despite the patient being placed on heparin, there was a recurrence of the PE three days later, requiring a repeat pulmonary thrombectomy. This case of recurrent VTE in a heterozygous FVL patient is unusual and should lead to new considerations on the approach to lifelong anticoagulation in these patients.

Comparative Outcomes of Peripheral Vascular Interventions in Patients on Chronic Anticoagulation with Factor Xa Inhibitors and Vitamin K Antagonists

BACKGROUND

In patients undergoing revascularization for peripheral arterial disease (PAD), low-dose Factor Xa inhibitors (FXaI) taken with aspirin improved limb and cardiovascular outcomes compared to aspirin alone. Furthermore, in atrial fibrillation and venous thromboembolism, FXaI are recommended over vitamin K antagonists (VKA) for chronic anticoagulation. While studies have evaluated different perioperative anticoagulation regimens in patients treated for PAD, the optimal regimen for chronic anticoagulation in patients with PAD undergoing peripheral vascular intervention (PVI) has not been determined. This analysis compares outcomes of patients after PVI that require chronic anticoagulation with FXaI and VKA.

METHODS

The Vascular Quality Initiative-PVI database was used. Patients consistently treated with FXaI or VKA before the procedure, at discharge, and on long-term follow-up were defined as those receiving chronic anticoagulation. Patient demographics, procedural details, and perioperative and long-term outcomes were compared between FXaI and VKA groups.

RESULTS

A total of 109,268 patients were analyzed, and 6,885 were chronically anticoagulated with FXaI (N = 2,427) or VKA (N = 4,458). Patients anticoagulated with VKA were more frequently males (65.3% vs. 61.0%, P < 0.001) with end-stage renal disease (9.7% vs. 4.6%, P < 0.001) and more likely to be treated for chronic limb-threatening ischemia (58.1% vs. 52.7%, P < 0.001). Rates of hematoma following PVI were significantly higher in patients taking VKA compared to FXaI (3.5% vs. 1.9%, P < 0.001). Multivariable logistic regression analysis showed that VKA were associated with increased perioperative hematoma than FXaI (odds ratio = 1.89 [1.30-2.82]). Compared to patients taking VKA, those receiving FXaI had lower rates of major amputation (6.7% vs. 8.4%, P = 0.020) and mortality (7.6% vs. 15.2%, P ≤ 0.001). Using Kaplan-Meier analysis, patients consistently anticoagulated with FXaI had improved amputation-free survival after PVI. Adjusting for significant patient and procedural characteristics, Cox proportional hazard regression demonstrated that there is an increased risk for major amputation or mortality in patients using VKA compared to FXaI (hazard ratio 1.61, [1.36-1.90]).

CONCLUSIONS

Chronic anticoagulation with FXaI as compared to VKA was associated with superior perioperative and long-term outcomes in patients with PAD undergoing PVI. FXaI should be the preferred agents over VKA for chronic anticoagulation in patients with PAD undergoing PVI.

Systematic review of clinical trials on antithrombotic therapy with factor XI inhibitors

INTRODUCTION AND OBJECTIVE

Data from phase 2 clinical trials suggest that factor XI inhibitors may exhibit a more favorable efficacy/safety profile compared to current antithrombotic therapies. The aim of this systematic review is to analyze the available evidence derived from these studies.

METHODS

A literature search in the PubMed, Cochrane Library, Scopus, EMBASE databases, and clinical trial registration platforms Clinical Trials and Cochrane Central Register of Controlled was conducted. In accordance with the PRISMA statement, results were reported.

RESULTS

A total of 18 completed or ongoing clinical trials addressing multiple scenarios, including atrial fibrillation, stroke, myocardial infarction, and venous thromboembolism, were identified. Evidence from 8 studies with available results was analyzed. Phase 2 studies with factor XI inhibitors, overall, demonstrated an acceptable efficacy and safety profile. The benefit-risk balance, in terms of reducing venous thromboembolism in patients undergoing total knee arthroplasty, was more favorable. For this scenario, factor XI inhibitors showed a 50% reduction in the overall rate of thrombotic complications and a 60% reduction in the rate of bleeding compared to enoxaparin. Modest results in studies involving patients with atrial fibrillation, stroke, and myocardial infarction were observed.

CONCLUSIONS

Factor XI inhibitors offer new prospects in antithrombotic treatment and prophylaxis. Ongoing phase 3 studies will help define the most suitable drugs and indications.