Bleeding with direct oral anticoagulants vs warfarin: clinical experience

Antithrombotic drug removal from whole blood using Haemoadsorption with a porous polymer bead sorbent

AIM

To evaluate the ability of the DrugSorb™-AntiThrombotic Removal (ATR) haemoadsorption device utilizing porous polymer bead sorbent technology to remove three commonly used antithrombotic drugs from whole blood.

METHODS AND RESULTS

We evaluated the removal of apixaban, rivaroxaban, and ticagrelor by the DrugSorb-ATR haemoadsorption device in a benchtop clinical scale model using bovine whole blood. Blood spiked at clinically relevant concentrations of an antithrombotic agent was continuously circulated through a 300-mL DrugSorb-ATR haemoadsorption device at a flow rate of 300 mL/min. Drug concentration was monitored over 6 h to evaluate drug removal. Results were compared with a control circuit without the haemoadsorption device. Removal rates at 30, 60, 120, and 360 minutes were: apixaban: 81.5%, 96.3%, 99.3% >99.8%; rivaroxaban: 80.7%, 95.1%, 98.9%, >99.5%; ticagrelor: 62.5%; 75%, 86.6%, >95% (all P <0.0001 vs. control). Blood pH and haematological parameters were not significantly affected by the DrugSorb-ATR haemoadsorption device when compared with the control circuit.

CONCLUSION

DrugSorb-ATR efficiently removes apixaban, rivaroxaban, and ticagrelor in a clinical-scale benchtop recirculation circuit with the bulk of removal occurring in the first 60 minutes. The clinical implications of these findings are currently investigated in patients undergoing on-pump cardiothoracic surgery in two US pivotal trials (ClinicalTrials.gov Identifiers: NCT04976530 and NCT05093504).

Dental implants and risk of bleeding in patients on oral anticoagulants: a systematic review and meta-analysis

Background

Dental implant placement is safe and predictable, yet optimal management of anticoagulated patients remains controversial. Whilst cessation of anticoagulation pre-operatively should decrease risks of bleeding, risk of thrombosis increases. We aim to define risk of bleeding in patients on oral anticoagulation who are undergoing dental implant placement, in order to establish best management.

Methods

This systematic review is registered with the National Institute for Health Research (NIHR) PROSPERO database (Registration No: CRD42021233929). We performed a systematic review as per Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidance. Studies were identified using an agreed search strategy within the OVID Gateway (this included Pubmed, MEDLINE, Cochrane Collaborative). Studies assessing bleeding complications in patients who were undergoing dental implant placement were selected. The primary outcome was bleeding events in anticoagulated patients undergoing dental implant placement. Secondary outcomes included any complication requiring further intervention.

Results

We identified 182 studies through screening, and after review of titles and abstracts reduced this to 8 studies. In these studies, 1467 participants received at least 2366 implants. Studies were analysed for quality using the ROBINS-I risk of bias tool. Four studies were retrospective case reviews, and four were prospective reviews, three of which also blinded the operator to anticoagulation status. There was significant heterogeneity between the included studies. Meta-analysis showed an increased risk of bleeding (RR, 2.30; 95% CI, 1.25-4.24 p = 0.37 I = 7%) when implants were placed in the presence of anticoagulation however these were not clinically significant haemorrhagic events.

Conclusion

The continuation of anticoagulants peri-operatively during dental implant surgery does increase the risk of clinically non-significant peri- and post-operative bleeding. Dental implant surgery encompasses a broad spectrum of procedures ranging from minor to more invasive surgery with simple local haemostatic measures mitigating the risk of bleeding. The decision to discontinue anticoagulants prior to dental implant surgery must consider patient and surgical factors with the clinician undertaking a risk-balance assessment.

Clinical Outcome in Patients With Intracerebral Hemorrhage Stratified by Type of Antithrombotic Therapy

Background: Antithrombotic therapy influences clinical outcome after spontaneous intracerebral hemorrhage (ICH). However, evidence on the effect of different antithrombotic therapies on outcome and a comparison between different therapies is scarce, while this is important for medical decision making. Therefore, we investigated clinical outcome after ICH stratified by type of antithrombotic therapy.

Patients/Methods: We performed a cohort study selecting consecutive ICH patients from our database, excluding patients without data on medication or therapeutic heparin use. Primary outcome was poor outcome (modified Rankin Scale ≥ 4) after 90 days. Secondary outcome was mortality at 90 days. We analyzed outcome and survival in patients with ICH using vitamin K antagonists (VKA), antiplatelet therapy (AP), and direct oral anticoagulant (DOAC) compared to no antithrombotic therapy adjusted for age, National Institutes of Health Stroke Scale (NIHSS), infratentorial localization, intraventricular extension, history of hypertension, diabetes, or stroke, and interaction between age and NIHSS.

Results: We included 916 patients (223 AP, 161 VKA, and 40 DOAC). VKA (adjusted odds ratio [aOR] 3.2, 95% confidence interval [CI], 1.6–6.3) and AP (aOR = 2.0, 95%CI: 1.1–3.7) were associated with poor outcome. DOAC use did not reach statistical significance (aOR = 2.4, 95%CI: 0.8–7.7). Patients who used any antithrombotic therapy had poorer survival compared to patients without antithrombotic treatment and patients using AP and DOAC had better survival compared to VKA after adjustment.

Conclusions: Patients with antithrombotic therapy have worse clinical outcome after ICH. Patients using VKA have higher risk of poor outcome and mortality compared to patients using AP. These findings highlight the deleterious effect of antithrombotic therapy in patients with ICH and stress the need for effective therapies for ICH patients.

Direct Oral Anticoagulants in Patients with Atrial Fibrillation and Renal Dysfunction

Atrial fibrillation and renal dysfunction often coexist, each disorder may predispose to the other and contribute to worsening prognosis. Both atrial fibrillation and chronic kidney disease are associated with increased risk of stroke and thromboembolic complications. Oral anticoagulation for stroke prevention is therefore recommended in patients with atrial fibrillation and decreased renal function. Each direct oral anticoagulant has unique pharmacologic properties of which clinician should be aware to optimally manage patients. The doses of direct oral anticoagulants require adjustment for renal function. There is debate regarding which equation, the Chronic Kidney Disease Epidemiology (CKD-EPI) equation vs. the Cockcroft-Gault equation, should be used to estimate glomerular filtration rate in patients with atrial fibrillation treated with direct oral anticoagulants. Our review tries to find arguments for benefit of direct oral anticoagulants in patients with renal dysfunction.

Recent evidence for direct oral anticoagulants in chronic kidney disease

PURPOSE OF REVIEW

The direct oral anticoagulants (DOACs) have emerged as an effective and safe alternative to vitamin K antagonists (VKAs) for stroke and venous thromboembolism (VTE) prevention. However, patients with chronic kidney disease (CKD) experience an increase in the risk of both thromboembolism and bleeding, and the risk-benefit profile of DOACs, particularly in advanced CKD remains a source of ongoing debate. This review summarizes the recent evidence on the effects of DOACs in CKD across a range of clinical indications including newly emerging indications.

RECENT FINDINGS

Data on early-to-moderate stage CKD derived from pivotal randomized controlled trials in broader atrial fibrillation and VTE populations support the favorable risk-benefit ratio of DOACs compared with VKAs in patients in these groups. However, safety data from observational studies comparing DOACs with VKAs in patients with atrial fibrillation and CKD (moderate to advanced) have been conflicting. Recent trials have evaluated the efficacy of low-dose DOACs on major cardiovascular outcomes, showing promising risk-benefit ratios in high-risk populations with concurrent CKD.

SUMMARY

Current data on patients with CKD derived from trials in the broader population suggest that DOACs are an effective alternative to VKAs in patients with early-to-moderate stage CKD. However, studies on patients with advanced CKD are lacking. Further randomized controlled trials, particularly those evaluating the risk of any clinically relevant bleeding as part of a more accurate assessment of the risk-benefit profile of DOACs in people with CKD, are needed.

Survey of current treatment practices for venous thromboembolism in patients with cystic fibrosis

BACKGROUND

Patients with cystic fibrosis (CF) and venous thromboembolism (VTE) pose therapeutic challenges including potential drug interactions between CF-related therapies and anticoagulants. Despite these challenges, there are no recommendations for VTE management specific to patients with CF. Our objective was to describe VTE treatment practices among Cystic Fibrosis Foundation (CFF)-accredited care centers and affiliate programs in the United States.

METHODS

An online survey was distributed to CF center directors. The survey included questions regarding centers' demographics and posed a series of hypothetical clinical scenarios to gather centers' VTE treatment practices including choice of anticoagulant, dosing practices, duration decisions, and monitoring efforts. Descriptive statistics were utilized to summarize the survey results.

RESULTS

The survey response rate was 56.3%. Most centers reported treating zero to five VTE episodes per year. The following anticoagulants were used most often for VTE treatment: low-molecular-weight heparin (LMWH) (73.2%), apixaban (36.6%), warfarin (35.2%), rivaroxaban (33.8%), and unfractionated heparin (18.3%). On a scale of 0 to 100, the median confidence level in managing anticoagulant therapy was 50. Many centers expressed a desire for a CF-specific VTE treatment guideline. The most commonly cited challenging clinical situations were managing anticoagulant therapy complications (26.5%) and drug-drug interactions (21.3%). For common VTE scenarios, pediatric patients were most often treated with LMWH and warfarin, whereas adult patients were more often treated with apixaban or rivaroxaban.

CONCLUSIONS

Survey results indicated CF care centers find managing VTE in patients with CF challenging and indicated that a CF-specific VTE treatment guideline would be helpful.

Efficacy of Direct Acting Oral Anticoagulant Drugs in Treatment of Left Atrial Appendage Thrombus in Patients With Atrial Fibrillation

Direct acting oral anticoagulants (DOACs) are increasingly used for thromboembolic prophylaxis in patients with atrial fibrillation (AF). However, there is limited data to evaluate the use of DOACs for the treatment of pre-existing left atrial appendage thrombus. We aimed to determine the efficacy of DOACs in treatment of left atrial appendage (LAA) thrombus utilizing transesophageal echocardiographic (TEE) and clinical outcomes. In this single-center study, we identified 33 patients that were treated for LAA thrombus with DOAC. Eighteen were treated with apixaban, 10 with dabigatran, and 5 with rivaroxaban. The primary endpoint was defined as resolution of LAA thrombus (in patients undergoing TEE), or death, major bleeding requiring transfusion, intracranial hemorrhage, ischemic stroke, or peripheral embolization. In this study, 15 of the 16 patients treated with DOACs who underwent follow-up TEE had resolution of LAA thrombus, with a mean duration of 112 days. Of the 15 patients who achieved resolution of the LAA thrombus, 14 had resolution by their first follow-up TEE. In the 17 patients without a follow-up TEE, 1 died of a retroperitoneal bleed (28 days after DOAC initiation), and 1 suffered an ischemic stroke (484 days after DOAC initiation). In general, patients without a follow-up TEE were older and had more co-morbidities. Although these results are descriptive and limited in number of patients, we believe this is ample evidence that DOACs are relatively safe and efficacious in treatment of patients with AF and concomitant LAA thrombus.

Multiple spontaneous hemorrhages after commencing warfarin therapy

A 94 year-old Japanese woman with renal dysfunction was admitted to our hospital for congestive heart failure caused by atrial fibrillation with rapid ventricular response. Considering the risk of stroke, warfarin was commenced. However, she developed shock following brachial and retroperitoneal hemorrhage 4 days after starting warfarin despite not being over-anticoagulated. She recovered after receiving blood transfusion and intravenous vitamin K2. Bleeding during warfarin administration occurs more frequently in older individuals with lower glomerular filtration rates, especially within the first 30 days of warfarin treatment. Physicians should therefore check for unexpected bleeding after commencing warfarin and be prepared to reverse anticoagulation.

Immediate versus delayed surgery for hip fractures in the elderly patients: a protocol for a systematic review and meta-analysis

BACKGROUND

Hip fractures are a major public health problem in elderly populations and are accompanied by high-mortality rates. Whether timing of surgery has an impact on morbidity and mortality has been discussed controversially, numerous studies suggest that the delay of surgery can significantly increase the risk of morbidity and mortality; others report that achieving a stable medical condition is more important than early surgery. The goal of our systematic review is to assess the impact of timing of surgery on health outcomes in patients aged 60 years or older with acute hip fracture. In addition, we will investigate differences in beneficial or harmful effects of timing of surgery in subgroups of patients based on demographic characteristics, physical status, and the use of anticoagulant medications.

METHODS

We will systematically search MEDLINE via Ovid, the Cochrane Library, Embase, PubMed, and clinical trial registries (from 1997 to 2017). In addition, we will search reference lists of pertinent reviews, archives of annual meetings of orthopaedic societies, and contact experts. We will include randomized controlled trials and non-randomized studies assessing the impact of timing of surgery after hip fracture in patients 60 years or older, published in English or German. Our outcomes of interest include health outcomes such as mortality, perioperative complications, functional capacity, and quality of life. We plan to perform meta-analyses if we have at least three sufficiently similar studies. If data are sufficient, we will conduct subgroup-analyses testing for differences between age groups, sex, patients' physical status as assessed with ASA (American Society of Anesthesiologists) scores, and the use of anticoagulation.

DISCUSSION

Since this is the first systematic review on this topic since 2010, our findings will help to inform clinical practice guidelines concerning timing of surgery in hip fractures. Furthermore, our findings could contribute to define an optimal time period for surgery for different groups of patients with acute hip fracture.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO 2017 CRD42017058216.

Preclinical and Clinical Data for Factor Xa and "Universal" Reversal Agents

Oral Factor Xa (FXa) inhibitors, a growing class of direct-acting anticoagulants, are frequently used to prevent stroke and systemic embolism in patients with atrial fibrillation and to prevent and treat venous thromboembolism. These drugs reduce the risk of clotting at the expense of increasing the risk of bleeding, and currently they have no specific reversal agent. However, andexanet alfa, a recombinant modified FXa decoy molecule, is in a late-phase clinical trial in bleeding patients, and ciraparantag, a small molecule that appears to reverse many anticoagulants including the FXa inhibitors, is in development. This review summarizes the published data to date on both drugs, which have the potential to change the management approach to patients with FXa inhibitor-associated major hemorrhage.

Preclinical and clinical data for factor Xa and "universal" reversal agents

Oral Factor Xa (FXa) inhibitors, a growing class of direct-acting anticoagulants, are frequently used to prevent stroke and systemic embolism in patients with atrial fibrillation and to prevent and treat venous thromboembolism. These drugs reduce the risk of clotting at the expense of increasing the risk of bleeding, and currently they have no specific reversal agent. However, andexanet alfa, a recombinant modified FXa decoymolecule, is in a late-phase clinical trial in bleeding patients, and ciraparantag, a small molecule that appears to reverse many anticoagulants including the FXa inhibitors, is in development. This review summarizes the published data to date on both drugs, which have the potential to change the management approach to patients with FXa inhibitoreassociated major hemorrhage.