Removing direct oral factor Xa inhibitor interferences from routine and specialised coagulation assays using a raw activated charcoal product

BACKGROUND

Direct oral anticoagulants (DOACs) are increasingly prescribed for the prevention and treatment of thrombosis. However, DOACs are associated with extensive interference in coagulation assays. Herein, we evaluate raw activated charcoal (AC) as an adsorbent material, to minimise DOAC-associated interferences in routine and specialised coagulation parameters on CS-series analysers (Sysmex, Kobe, Japan).

METHODS

Commercial human-derived non-anticoagulated plasma materials, with or without increasing concentrations of anticoagulant, were assayed for routine and specialised coagulation parameters before and after treatment with AC.

RESULTS

Treatment of non-anticoagulated plasma with raw AC had minimal impact on routine and specialised coagulation parameters available on the CS-series; however, clinically relevant prolongations of certain activated partial thromboplastin time (APTT)-based assays were observed after treatment. Furthermore, in apixaban- and rivaroxaban-containing plasma material, AC efficiently adsorbed therapeutic and supratherapeutic DOAC concentrations; and, treatment with raw AC resolved DOAC-associated interferences on all affected routine and specialised coagulation parameters.

CONCLUSIONS

Overall, raw AC efficiently adsorbed apixaban and rivaroxaban from human-derived plasma, without significantly affecting the majority of underlying routine and specialised coagulation parameters available on CS-series analysers.

Factors influencing real-life use of direct oral anticoagulants in patients with cerebral sinus and venous thrombosis

BACKGROUND

Direct oral anticoagulants (DOAC) are advocated as equally effective to vitamin K antagonists (VKA) for the treatment of patients with cerebral sinus and venous thrombosis (CSVT). However, data concerning the real-life management practices in CSVT patients are is lacking.

METHODS

Prospective CSVT databases from four large academic medical centers were retrospectively studied. Demographics, clinical presentations, risk factors, radiological and outcome parameters were compared between CSVT patients treated with DOAC and VKA.

RESULTS

Out of 504 CSVT patients, 43 (8.5%) were treated with DOAC, and the remaining 461 (91.5%) were treated with VKA. All patients with antiphospholipid syndrome (APLA) were treated with VKA (61 vs. 0, p=0.013). Patients with a history or presence of malignancy were also more often treated with VKA (16% vs. 5%, p=0.046). Other risk factors for thrombosis did not differ between the groups. There were no differences in clot extent or location and no differences in the percentage of favorable outcomes or mortality were observed.

CONCLUSION

Our data suggests that only malignancy and antiphospholipid antibodies significantly influenced physician's decisions towards choosing VKA rather than DOAC. DOAC appear to be as effective and safe as VKA in patients with CSVT.

Latest outcomes of transcatheter left atrial appendage closure devices and direct oral anticoagulant therapy in patients with atrial fibrillation over the past 5 years: a systematic review and meta-analysis

Left atrial appendage closure (LAAC) are emerging treatment for patients with atrial fibrillation (AF). However, data on the safety, efficacy, and medications for LAAC devices in patients with AF are lacking. We aimed to investigate the incidence of all-cause mortality, stroke, and major bleeding in AF patients with LAAC devices and DOACs. Moreover, we aimed to investigate the incidence rate of device-related thrombus (DRT) and the medications used in the management of AF patients with LAAC devices to gain insights into achieving better outcome. Based on a literature search using PubMed, EMBASE, Cochrane Library, and Web of Science databases between January 2015 and December 2020, eight LAAC device studies that used WATCHMAN and Amulet, and three DOAC studies that used rivaroxaban, with a total of 24,055 AF patients (LAAC devices, n = 2855; DOAC, n = 21,200), were included. A random-effects model was used to incorporate heterogeneity among studies. The pooled incidence of events per person-years were as follows: all-cause mortality, 0.06 (95% confidence interval [CI] 0.02-0.10) for WATCHMAN, 0.04 (95% CI 0.00-0.14) for Amulet, and 0.03 (95% CI 0.01-0.04) for rivaroxaban; stroke; 0.02 (95% CI 0.00-0.04) for WATCHMAN, 0 for Amulet, and 0.01 (95% CI 0.01-0.02) for rivaroxaban; major bleeding, 0.04 (95% CI 0.02-0.06) for WATCHMAN, 0.02 (95% CI 0.00-0.06) for Amulet, and 0.02 (95% CI 0.01-0.03) for rivaroxaban. The incidence rate of DRT was 2.3%, and complications were reported in 9%. The incidence of all-cause mortality, stroke, and major bleeding were similar between LAAC devices and DOACs. The rate of complications was acceptable, and those of DRT were lower than the average incidence reported in previous studies. However, further follow-up is needed. Concomitant anticoagulant and antiplatelet therapies should be further evaluated to find the optimal regimen for AF patients with LAAC devices.

Reversal of direct oral anticoagulants in adult hip fracture patients. A systematic review and meta-analysis

BACKGROUND

Increasing numbers of patients are taking Direct Oral Anticoagulants at the time of hip fracture. Evidence is limited on how and if the effects of DOAC's should be reversed before surgical fixation. Wide variations in practice exist. We conducted a systematic review to investigate outcomes for three reversal strategies. These were: "watch and wait" (also referred to as "time-reversal"), plasma product reversal and reversal with specific antidotes.

METHODS

A systematic search was conducted using multiple databases. Results were obtained for studies directly comparing different DOAC reversal strategies in hip fracture patients and for studies comparing DOAC-taking hip fracture patients (including patients "reversed" using any method and "non-reversed" patients) against matched controls taking either a vitamin-K antagonist or not receiving anticoagulation therapy. This allowed construction of a network meta-analysis to indirectly compare outcomes between "reversed" and "non-reversed" DOAC patients. With respect to "watch and wait"/"time-reversal", a cut-off time to surgery of 36 hours was used to distinguish between "time-reversed" and "non time-reversed" DOAC patients. The primary outcome was early/inpatient mortality, reported as Odds Ratios (OR).

RESULTS

No studies investigating plasma products or reversal agents specifically in hip fracture patients were obtained. Fourteen studies were suitable for analysis of "watch and wait"/"time- reversal". Two studies directly compared "time-reversed" and "non time-reversed" DOAC-taking hip fracture patients (58 "time-reversed", 62 "non time-reversed"). From 12 other studies we used indirect comparisons between "time-reversed" and "non time-reversed" DOAC patients (total, 357 "time-reversed", 282 "non time-reversed"). We found no statistically significant differences in mortality outcomes between "time-reversal" and "non time-reversal" (OR 1.48 [95%CI: 0.29-7.53]). We also did not find a statistically significant difference between "time reversal" and "non time-reversal" in terms of blood transfusion requirements (OR 1.16 [95% CI 0.42-3.23]). However, several authors described that surgical delay is associated with worse outcomes related to prolonged hospitalisation, and that operating within 36 hours is safe.

CONCLUSIONS

We suggested against "watch and wait" to reverse the DOAC effect in hip fractures. Further work is required to assess the optimal timing for surgery as well as the use of plasma products or specific antidotes in DOAC-taking hip fracture patients.

Do direct oral anticoagulants (DOACs) cause delayed surgery, longer length of hospital stay, and poorer outcome for hip fracture patients?

PURPOSE

The perioperative consequences of direct oral anticoagulants (DOACs) in hip fracture patients are not sufficiently investigated. The primary aim of this study was to determine whether DOAC-users have delayed surgery compared to non-users. Secondarily, we studied whether length of hospital stay, mortality, reoperations and bleeding complications were influenced by the use of DOAC.

METHODS

The medical records of 314 patients operated for a hip fracture between 2016 and 2017 in a single trauma center were assessed. Patients aged < 60 and patients using other forms of anticoagulation than DOACs were excluded. Patients were followed from admission to 6 months postoperatively. Surgical delay was defined as time from admission to surgery. Secondary outcomes included length of hospital stay, transfusion rates, perioperative bleeding loss, postoperative wound ooze, mortality and risk of reoperation. The use of general versus neuraxial anaesthesia was registered. Continuous outcomes were analysed using Students t test, while categorical outcomes were expressed by Odds ratios.

RESULTS

47 hip fracture patients (15%) were using DOACs. No difference in surgical delay (29 vs 26 h, p = 0.26) or length of hospital stay (6.6 vs 6.1 days, p = 0.34) were found between DOAC-users and non-users. DOAC-users operated with neuraxial anaesthesia had longer surgical delay compared to DOAC-users operated with general anaesthesia (35 h vs 22 h, p < 0.001). Perioperative blood loss, transfusion rate, risk of bleeding complications and mortality were similar between groups.

CONCLUSION

Hip fracture patients using DOAC did not have increased surgical delay, length of stay or risk of reported bleeding complications than patients without anticoagulation prior to surgery. The increased surgical delay found for DOAC-users operated with neuraxial anaesthesia should be interpreted with caution.

Bleeding rates of Veterans taking apixaban or rivaroxaban for atrial fibrillation or venous thromboembolism

This study examined potential differences in bleeding between apixaban and rivaroxaban, the most commonly utilized direct oral anticoagulants at the Richard L. Roudebush VA Medical Center. Additionally, the analysis included a comparison between observed and literature-reported bleeding rates. This retrospective chart review examined 452 (39%) Veterans receiving rivaroxaban and 716 (61%) Veterans receiving apixaban. Bleeding rates were expressed per 100 patient-years and the overall rates were analyzed as the primary analysis. Secondary objectives included comparisons based on indication and severity, as well as comparisons to literature-reported bleed rates, time to bleeding event, and location of the bleed. The analysis did not detect any statistically significant differences between apixaban and rivaroxaban in terms of overall, (ARR 0.90% per 100 patient-years, 95% CI - 0.58 to 2.38%, p > 0.05) major, (ARR 0.22% per 100 patient-years, 95% CI - 0.74 to 1.17%, p > 0.05) or non-major clinically relevant (ARR 0.35% per 100 patient-years, 95% CI - 0.57 to 1.27%, p > 0.05) bleeding. Observed bleeding for both rivaroxaban and apixaban in the Veteran population exceeded the rates reported by the literature when used for atrial fibrillation (1.96% vs. 0.15%, p < 0.05; 1.08% vs. 0.16%, p < 0.05) but the opposite was seen for long term venous thromboembolism (VTE) treatment (3.97% vs. 8.03%, p < 0.0001; 0.14% vs. 15.51%, p < 0.0001) or extended VTE prophylaxis (0.07% vs 5.98%, p < 0.0001; 0.07% vs 1.88%, p < 0.01). Results from this study suggest these agents impart similar levels of risk, but variations in bleeding risk between the Veteran population and the patients in the original clinical trials may exist.

[Anticoagulants: current topics]

Despite the introduction of direct oral anticoagulants (DOAC), the need for more effective and safer antithrombotic strategies exists. Recently, the findings stating that the contact system is important for thrombus formation has identified factor XI as a potential target for new anticoagulants. Approximately 20-30% of patients who develop venous thromboembolism (VTE) also have cancer. To date, the drugs primarily used in the treatment of VTE are heparin in the acute phase and warfarin in the chronic phase. Recently, a large-scale international clinical trial, which examined the composite outcomes of VTE recurrence and major bleeding in cancer patients, found that edoxaban, a direct factor Xa inhibitor, is not inferior to low-molecular-weight heparin. The study also showed that DOACs have a promising potential to prove therapeutically effective in future studies. Anticoagulants are associated with a severe side effect, bleeding, which makes emergency neutralization an important concern. Four-factor prothrombin complex concentrate can be used to reverse the effect of warfarin and could also be effective as a neutralizing agent in patients having received DOACs. Moreover, more specific reversing agents include the approved human monoclonal antibody fragment idarucizumab for reversing the effects of dabigatran.

Management of Elective Surgery and Emergent Bleeding with Direct Oral Anticoagulants

PURPOSE OF REVIEW

The purpose of this review was to offer practical management strategies for when patients receiving direct oral anticoagulants require elective surgery or present with bleeding complications.

RECENT FINDINGS

Clinical practice guidelines are now available on the timing of periprocedural interruption of treatment with the newer direct oral anticoagulants based on their pharmacodynamics and pharmacokinetics and based on findings from cohort studies and clinical trials. An antibody that reverses the effects of dabigatran is now available, and a factor Xa decoy is being developed as an antidote to apixaban, betrixaban, edoxaban, and rivaroxaban. The timing of interruption of direct oral anticoagulants for elective surgery is based on multiple factors, including pharmacologic properties and interactions, the patient's renal function, and the type of planned surgery. There is little role for low-molecular-weight heparin bridging. Idarucizumab is the treatment of choice for dabigatran-related life-threatening bleeding, while andexanet alfa is being developed to reverse factor Xa inhibitors.

Guidance for the prevention and treatment of the post-thrombotic syndrome

The post-thrombotic syndrome (PTS) is a frequent, potentially disabling complication of deep vein thrombosis (DVT) that reduces quality of life and is costly. Clinical manifestations include symptoms and signs such as leg pain and heaviness, edema, redness, telangiectasia, new varicose veins, hyperpigmentation, skin thickening and in severe cases, leg ulcers. The best way to prevent PTS is to prevent DVT with pharmacologic or mechanical thromboprophylaxis used in high risk patients and settings. In patients whose DVT is treated with a vitamin K antagonist, subtherapeutic INRs should be avoided. We do not suggest routine use of elastic compression stockings (ECS) after DVT to prevent PTS, but in patients with acute DVT-related leg swelling that is bothersome, a trial of ECS is reasonable. We suggest that selecting patients for catheter-directed thrombolytic techniques be done on a case-by-case basis, with a focus on patients with extensive thrombosis, recent symptoms onset, and low bleeding risk, who are seen at experienced hospital centers. For patients with established PTS, we suggest prescribing 20–30 mm Hg knee-length ECS to be worn daily. If ineffective, a stronger pressure stocking can be tried. We suggest that intermittent compression devices or pneumatic compression sleeve units be tried in patients with moderate-to-severe PTS whose symptoms are inadequately controlled with ECS alone. We suggest that a supervised exercise training program for 6 months or more is reasonable for PTS patients who can tolerate it. We suggest that management of post-thrombotic ulcers should involve a multidisciplinary approach. We briefly discuss upper extremity PTS and PTS in children.

Guidance for the prevention and treatment of cancer-associated venous thromboembolism

Venous thromboembolism (VTE) is a highly prevalent complication of malignancy with emerging changes in incidence, diagnosis and treatment paradigms. This manuscript, initiated by the Anticoagulation Forum, provides clinical guidance based on existing guidelines and consensus expert opinion where guidelines are lacking. We address a) the appropriate workup to search for occult malignancy in patients with idiopathic VTE, b) identification of high-risk cancer patients for primary thromboprophylaxis, c) the appropriate immediate and long-term treatment for people with cancer diagnosed with acute thromboembolism, d) the appropriate duration of anticoagulation and e) the appropriate treatment strategy in patients with recurrent VTE on anticoagulation. Areas of controversy and future directions in this field are highlighted.

Guidance for the practical management of the heparin anticoagulants in the treatment of venous thromboembolism

Venous thromboembolism (VTE) is a serious and often fatal medical condition with an increasing incidence. Despite the changing landscape of VTE treatment with the introduction of the new direct oral anticoagulants many uncertainties remain regarding the optimal use of traditional parenteral agents. This manuscript, initiated by the Anticoagulation Forum, provides clinical guidance based on existing guidelines and consensus expert opinion where guidelines are lacking. This specific chapter addresses the practical management of heparins including low molecular weight heparins and fondaparinux. For each anticoagulant a list of the most common practice related questions were created. Each question was addressed using a brief focused literature review followed by a multidisciplinary consensus guidance recommendation. Issues addressed included initial anticoagulant dosing recommendations, recommended baseline laboratory monitoring, managing dose adjustments, evidence to support a relationship between laboratory tests and meaningful clinical outcomes, special patient populations including extremes of weight and renal impairment, duration of necessary parenteral therapy during the transition to oral therapy, candidates for outpatient treatment where appropriate and management of over-anticoagulation and adverse effects including bleeding and heparin induced thrombocytopenia. This article concludes with a concise table of clinical management questions and guidance recommendations to provide a quick reference for the practical management of heparin, low molecular weight heparin and fondaparinux.

Guidance for the use of thrombolytic therapy for the treatment of venous thromboembolism

Patients with venous thromboembolism (VTE) are prone to the development of both short-term and long-term complications that can substantially affect their functional capacity and quality of life. Patients with deep vein thrombosis (DVT) often develop recurrent VTE or the post-thrombotic syndrome, whereas patients with pulmonary embolism (PE) can develop long-term symptoms and functional limitations along a broad spectrum extending to full-blown chronic thromboembolic pulmonary hypertension. Clinicians who care for patients showing severe clinical manifestations of DVT and PE are often faced with challenging decisions concerning whether and how to escalate to more aggressive treatments such as those involving the use of thrombolytic drugs. The purpose of this chapter is to provide guidance on how best to individualize care to these patients.

Guidance for the practical management of warfarin therapy in the treatment of venous thromboembolism

Venous thromboembolism (VTE) is a serious and often fatal medical condition with an increasing incidence. The treatment of VTE is undergoing tremendous changes with the introduction of the new direct oral anticoagulants and clinicians need to understand new treatment paradigms. This article, initiated by the Anticoagulation Forum, provides clinical guidance based on existing guidelines and consensus expert opinion where guidelines are lacking. Well-managed warfarin therapy remains an important anticoagulant option and it is hoped that anticoagulation providers will find the guidance contained in this article increases their ability to achieve optimal outcomes for their patients with VTE Pivotal practical questions pertaining to this topic were developed by consensus of the authors and were derived from evidence-based consensus statements whenever possible. The medical literature was reviewed and summarized using guidance statements that reflect the consensus opinion(s) of all authors and the endorsement of the Anticoagulation Forum’s Board of Directors. In an effort to provide practical and implementable information about VTE and its treatment, guidance statements pertaining to choosing good candidates for warfarin therapy, warfarin initiation, optimizing warfarin control, invasive procedure management, excessive anticoagulation, subtherapeutic anticoagulation, drug interactions, switching between anticoagulants, and care transitions are provided.

Erratum to: Pharmacology of anticoagulants used in the treatment of venous thromboembolism

Anticoagulant drugs are the foundation of therapy for patients with VTE. While effective therapeutic agents, anticoagulants can also result in hemorrhage and other side effects. Thus, anticoagulant therapy selection should be guided by the risks, benefits and pharmacologic characteristics of each agent for each patient. Safe use of anticoagulants requires not only an in-depth knowledge of their pharmacologic properties but also a comprehensive approach to patient management and education. This paper will summarize the key pharmacologic properties of the anticoagulant agents used in the treatment of patients with VTE.

Guidance for the management of venous thrombosis in unusual sites

Venous thromboembolism (VTE) is a serious and often fatal medical condition with an increasing incidence. The treatment of VTE is undergoing tremendous changes with the introduction of the new direct oral anticoagulants and clinicians need to understand new treatment paradigms. This manuscript, initiated by the Anticoagulation Forum, provides clinical guidance based on existing guidelines and consensus expert opinion where guidelines are lacking. In this chapter, we address the management of patients presenting with venous thrombosis in unusual sites, such as cerebral vein thrombosis, splanchnic vein thrombosis, and retinal vein occlusion. These events are less common than venous thrombosis of the lower limbs or pulmonary embolism, but are often more challenging, both for the severity of clinical presentations and outcomes and for the substantial lack of adequate evidence from clinical trials. Based on the available data, we suggest anticoagulant treatment for all patients with cerebral vein thrombosis and splanchnic vein thrombosis. However, in both groups a non-negligible proportion of patients may present with concomitant bleeding at the time of diagnosis. This should not contraindicate immediate anticoagulation in patients with cerebral vein thrombosis, whereas for patients with splanchnic vein thrombosis anticoagulant treatment should be considered only after the bleeding source has been successfully treated and after a careful assessment of the risk of recurrence. Finally, there is no sufficient evidence to support the routine use of antithrombotic drugs in patients with retinal vein occlusion. Future studies need to assess the safety and efficacy of the direct oral anticoagulants in these settings.

Pharmacology of anticoagulants used in the treatment of venous thromboembolism

Anticoagulant drugs are the foundation of therapy for patients with VTE. While effective therapeutic agents, anticoagulants can also result in hemorrhage and other side effects. Thus, anticoagulant therapy selection should be guided by the risks, benefits and pharmacologic characteristics of each agent for each patient. Safe use of anticoagulants requires not only an in-depth knowledge of their pharmacologic properties but also a comprehensive approach to patient management and education. This paper will summarize the key pharmacologic properties of the anticoagulant agents used in the treatment of patients with VTE.

Postoperative bleeding risk for oral surgery under continued rivaroxaban anticoagulant therapy

OBJECTIVES

The purpose of this study was to assess the risk of postoperative bleeding complications after oral procedures performed under continued mono or dual anticoagulation therapy with rivaroxaban (and aspirin).

METHODS

This retrospective single-center observational study included 52 oral procedures performed under continued oral anticoagulant therapy with rivaroxaban (20 mg/day). Among them, two procedures were performed under continued dual therapy with aspirin (100 mg/day) added to the regimen. Postoperative bleeding events were compared with 285 oral procedures in patients without any anticoagulation/antiplatelet therapy.

RESULTS

Postoperative bleeding complications after oral surgery occurred significantly more often in patients under continued rivaroxaban therapy (11.5 %) than in the control cases without anticoagulation/antiplatelet medication (0.7 %). All of the bleeding events were manageable: Two of them were treated with local compression, three by applying new fibrin glue with (one case) or without (two cases) secondary sutures, one occurred during a weekend and was therefore treated under inpatient conditions with suture replacement. All postoperative bleeding episodes occurred during the first postoperative week.

CONCLUSIONS

According to our data, continued anticoagulation therapy with rivaroxaban significantly increases postoperative bleeding risk for oral surgical procedures, although the bleeding events were manageable.

CLINICAL RELEVANCE

Oral surgeons, cardiologists, general physicians, and patients should be aware of the increased bleeding risk after oral surgical procedures. Close observation up to 1 week postoperatively is advisable to prevent excessive bleeding.