Vitamin K Antagonists Research Articles

An external validation of DOAC score in patients with atrial fibrillation following transcatheter aortic valve replacement

Abstract Background Bleeding events, particularly in patients with atrial fibrillation (AF) and those with severe aortic stenosis undergoing transcatheter aortic valve replacement (TAVR), are a major clinical concern and are associated with a worse prognosis. The DOAC Score (1) has recently been introduced to predict bleeding risk in patients with AF taking direct oral anticoagulants (DOACs). However, further validation is required to confirm its ability. Objective This study aims to evaluate the predictive ability of the DOAC Score for bleeding events in Asian patients with AF undergoing TAVR. Methods In this multicentre, retrospective, observational cohort study, patients with AF who underwent TAVR were included. The data was obtained from the Japanese multicentre registry, which comprises 19 centres from 2013 to 2019. Bleeding was defined as any post-discharge bleeding after TAVR. The primary endpoint was the incidence of all bleeding events in 3 populations: the overall population, the DOAC cohort, and the vitamin K antagonist (VKA) cohort. Results This study included 1230 patients with a mean age of 84.6 ± 5.1 years, of whom 457 were males. Among them, 465 patients (37.8%) were treated with a VKA while the rest were treated with a DOAC. Patients were divided into three groups according to their DOAC Score: 380 patients (30.1%) were in the ≤ moderate risk group with a DOAC Score of 7 or less, 497 patients (40.4%) were in the high-risk group with a DOAC Score of 8 or 9, and 353 patients (28.7%) were in the very high-risk group with a DOAC Score over 10. The cumulative incidence of all bleeding at 5 years in the overall population was significantly different in the 3 risk groups: ≤ moderate: 8.4%, high-risk: 10.8%, very high-risk: 21.6%, respectively (p< 0.01). The incidence was also significantly different in the DOAC and VKA cohorts (p<0.01 and p=0.03, respectively). Conclusion The recently published DOAC Score is well predictive of bleeding risk in Asian patients with AF after TAVR. The score may be useful in predicting bleeding in patients taking both DOAC and VKA.Graphical abstract

Major bleeding complications and antithrombotic treatment after isolated surgical bioprosthetic aortic valve replacement

Abstract Background Despite advancements in surgical techniques and perioperative care, post-operative bleeds and stroke remain significant concerns after bioprosthetic surgical aortic valve replacement (SAVR). Purpose We assessed the incidence of short-term (30d) and long-term major bleeds and strokes and their relations to antithrombotic treatment after isolated bioprosthetic SAVR. Methods The CAREAVR study included 721 patients who underwent isolated SAVR at four Finnish university hospitals between 2002 and 2014. The day-to-day information on short-term antithrombotic treatment was available from a subgroup including 227 patients, of whom 138 (60.7%) had preoperative aspirin. Preoperative aspirin was usually discontinued the day before the index surgery. Enoxaparin 1mg/kg twice daily and vitamin K antagonist (VKA) were routinely initiated on the first postoperative day, and enoxaparin continued until the INR remained at a therapeutic level ≥ 2.0 for two days. The routine duration of VKA treatment after surgery was 3 months. Results The median follow-up time was 4.9 (interquartile range 3.0–7.0) years. During the short-term 30-day period, 31 (4.3%) patients had a major bleed, and 13 (1.8%) patients experienced a major stroke. A vast majority of the bleeding (80.6%) occurred within two days after the surgery, and the tail effect of preoperative aspirin (5-7d) was present in 51.6% of episodes, indicating unintentional triple antithrombotic therapy. During the long-term follow-up (>30d after the index surgery), 40 (5.5%) major bleeding episodes occurred, and 47 (6.5%) patients experienced a major stroke. Overall, 23 (57.5%) of the patients with major bleeding were on OAC during the event. In addition, 13 (27.7%) of the patients experiencing major stroke during the long-term follow-up were on OAC during the event. Conclusions Compared to major strokes, the incidence of perioperative major bleeds was over twofold, the majority occurring during the tail effect of preoperative aspirin. During the long-term follow-up, the risks of stroke and bleeding were equal, and the majority of bleeding episodes appeared during anticoagulation treatment.

The triglyceride-glucose index is a marker of thromboembolic events in atrial fibrillation patient under oral anticoagulation therapy

Abstract Background Atrial fibrillation (AF) increases the risk of stroke and thromboembolism; and appropriate risk stratification is central for better targeted patient management. The triglyceride-glucose (TyG) index indirectly assesses insulin resistance, and has been associated with cardiovascular risk. Purpose To investigate whether the TyG index could be a biomarker for assessing the risk of thromboembolic events in patients with AF. Methods We performed an observational prospective cohort study including outpatients diagnosed with AF starting vitamin K antagonist (VKA) or direct-acting oral anticoagulants (DOAC) therapy from January, 2016 to November, 2021. The primary endpoint was a combination of thromboembolic events, considered as the composite of myocardial infarction, and/or venous thromboembolism, and/or ischemic stroke/transient ischemic attack, over 2 years of follow-up. The TyG index was calculated as the natural logarithm (Ln) of the product of baseline plasma glucose and triglyceride using the following formula: Ln [fasting triglycerides (mg/dL) × fasting glucose (mg/dL)]/2. Patients were stratified into tertiles according to their TyG index (ie. first tertile: TyG index <4.59; second tertile: TyG index 4.59-4.83; third tertile: TyG index >4.83). Results We included 2907 patients (median age 77 [70-83] years; 52.5% female). The median TyG index was 4.71 (4.53-4.91), and 34% (989) where in the third tertile of TyG index. During a follow-up of 2 years, 209 (7.2%) patients suffered a thromboembolic event. Compared to patients in the first or second tertiles of TyG index, patients in the third tertile had an increased annual event rate of thromboembolic events (3.40 per 100 patient-years vs. 4.76 per 100 patient-years, p=0.043; and 3.41 per 100 patient-years vs. 4.76 per 100 patient-years, p=0.044), and higher incidence rate ratio (1.41 [95% CI 1.01-1.98], p=0.044 vs. first tertile; 1.40 [95% CI 1.01-1.97], p=0.044 vs. second tertile). Cox regression analyses adjusted for several risk factors demonstrated that the TyG index was an independent predictor for thromboembolic events (aHR 1.82; 95% CI 1.15-2.89; p=0.011). Patients in the third tertile of TyG index presented a 64% higher risk of thromboembolic events (aHR 1.64; 95% CI 1.17-2.29; p=0.004) (Table), with significantly lower event free survival (log-rank test p-value = 0.016) (Figure). Conclusions In this real-world cohort of AF patients under oral anticoagulation therapy, elevated TyG index was an independent risk factor for thromboembolic events. The TyG index is a simple, low-cost indicator, that could be used as a screening tool in everyday clinical practice.

Optimal anticoagulant strategy for periprocedural management of atrial fibrillation ablation: a systematic review and network meta-analysis

Abstract Background This network meta-analysis was performed to rank the safety and efficacy of periprocedural anticoagulant strategies in patients undergoing atrial fibrillation ablation. Methods MEDLINE, EMBASE, CENTRAL, and Web of Science were searched to identify randomized controlled trials comparing anticoagulant regimens in patients undergoing atrial fibrillation ablation up to July 1, 2021. The primary efficacy and safety outcomes were thromboembolic and major bleeding events, respectively, and the net clinical benefit was investigated as the primary-outcome composite. Results Seventeen studies were included (n = 6950). The mean age ranged from 59 to 70 years; 74% of patients were men and 55% had paroxysmal atrial fibrillation. Compared with the uninterrupted vitamin-K antagonist strategy, the odds ratios for the composite of primary safety and efficacy outcomes were 0.61 (95%CI: 0.31–1.17) with uninterrupted direct oral anticoagulants, 0.63 (95%CI: 0.26–1.54) with interrupted direct oral anticoagulants, and 8.02 (95%CI: 2.35–27.45) with interrupted vitamin-K antagonists. Uninterrupted dabigatran significantly reduced the risk of the composite of primary safety and efficacy outcomes (odds ratio, 0.21; 95%CI, 0.08–0.55). Conclusion Uninterrupted direct oral anticoagulants are preferred alternatives to uninterrupted vitamin-K antagonists. Interrupted direct oral anticoagulants may be feasible as alternatives. Our results support the use of uninterrupted direct oral anticoagulants as the optimal periprocedural anticoagulant strategy for patients undergoing atrial fibrillation ablation.

Vitamin K2 and the Vitamin-K-Cycle-Enzyme VKORC1L1 improve endothelial regeneration by inhibiting endothelial-mesenchymal transition, inflammatory cell activation and ferroptosis

Abstract Introduction Vascular inflammation is a crucial contributor to atherosclerosis, in which oxidative stress, endoplasmic reticulum (ER) stress and transition of endothelial to mesenchymal cells (EndMT) are of critical importance. Vitamin-K-antagonists (VKA) promote vascular dysfunction, while dietary vitamin K intake was proposed to reduce incidence of coronary artery disease, but the mechanisms remain unresolved. Key enzyme for regeneration of vitamin K is the Vitamin K epoxide reductase complex subunit 1 (VKORC1), which also represents the pharmacological target of VKA. VKOR-like1 (VKORC1L1) is an isoenzyme of VKORC1, which resides at the ER-membrane, exerts antioxidative properties and is involved in vitamin K maintenance. Aim of this study was to investigate the role of Vitamin K2 and the VKOR-enzymes in endothelial cell inflammation. Methods and Results In human coronary artery endothelial cells (HCAEC), Vitamin K2 improves endothelial regeneration by increasing proliferation and cell viability and by reducing both apoptosis and ferroptosis (relative viability: RSL3 0.11 ± 0.01 vs 0.32 ± 0.05 RSL3+K2-1µM vs. 0.44 ± 0.11 RSL3+K2-10µM, p<0.001). Moreover, Vitamin K2-supplementation inhibits EndMT by reducing expression of mesenchymal markers (Calponin, SM22; Fig.1). In silico analyses of the proteome of human coronary atherosclerosis revealed increased expression of VKORC1L1, but not of VKORC1. In vitro induction of oxidative stress and ER-Stress promoted time- and dose-dependent enhanced expression of VKORC1L1, without altering VKORC1 expression (H2O2: 2.3-fold vs. 0.8-fold after 40 minutes, p=0.04; tunicamycin: 1 μg/ml: 1.43-fold vs. 0.8-fold, p<0.01). Likewise, siRNA-mediated VKORC1L1 knockdown induces an inflammatory gene signature with upregulation of NFkB-signalling and endoplasmic reticulum stress (NF-κB: 1.95-fold ± 0.13, GRP78: 1.32-fold ± 0.04 vs. control, p<0.01). Furthermore, VKORC1L1 downregulation increased formation of reactive oxygen species (ROS) and reduced proliferation (EdU signal: 0.56 ± 0.02 vs. control, p < 0.01). In contrast, VKORC1-knockdown does not impair endothelial regeneration and function (Fig.2). Vitamin K2 reduces vascular inflammation and endoplasmic reticulum stress in the case of VKORC1-, but not VKORC1L1-knockdown. In addition, inducing EndMT resulted in a reduction of VKORC1L1, but not of VKORC1, while VKORC1L1-knockdown aggravates EndMT. Conclusion VKORC1 and its isoenzyme VKORC1L1 exhibit divergent effects on endothelial cell inflammation. Further studies are warranted to shed light on the regulation of the enzymes to improve our understanding regarding vascular side effects of VKA treatment and beneficial effects of vitamin K supplementation.

The incidence of death and risk factors for mortality following major bleeding in patients anticoagulated with factor Xa inhibitors: an observational study in the UK clinical setting (AXIOM UK)

Abstract Background Major bleeding (MB) in association with anticoagulant use results in significant mortality. Mortality can be directly attributed to bleeding, or may follow bleeding complications such acute kidney injury, myocardial infarction, stroke and other cardiovascular events. Most real-world data relating to bleeding mortality is derived from cohorts receiving vitamin-K antagonists. We investigated all-cause mortality (ACM) after MB in a large cohort anticoagulated with Factor Xa inhibitors (FXai), e.g. direct oral anticoagulants (DOAC) rivaroxaban, apixaban and low-molecular-weight heparins (LMWH). Purpose To describe incidence rates of and risk factors for ACM following MB in patients receiving FXai. To investigate MB related ACM by bleeding site, treatment indication, treatment subgroups and individual and cumulative time periods. Methods Retrospective cohort analysis of new users of FXai, between 2012-2020, for therapeutic indications including atrial fibrillation (AF), venous thromboembolism, bioprosthetic cardiac valves or adult congenital heart disease was conducted. MB was defined by the International Society on Thrombosis and Haemostasis (ISTH) criteria. Incidence rates were reported per 100 person-years. Sub-distribution hazard ratios with 95% confidence intervals (95% CI) were estimated from Fine and Gray regression models accounting for competing risks. Results In 240,357 new users of FXai, 88% used an oral FXai. The most common FXai indication was AF (72%). There were 10,163 patients (4.2%) hospitalised for bleeding events during FXai use. Of these, 3,873 MB events (38%) fulfilled the ISTH definition of MB and 1312 died during 3,542 person years of follow-up (Table 1). ACM incidence rates varied by time, indication, bleeding subtype, and drug type. ACM occurred in 926 patients (23.9%) in the first month. Mortality rates were highest in the first month 607 (95% CI 568-647) per 100 person years, the rates then decreased over the year but remained elevated throughout the first year compared with subsequent years. Those receiving LMWH had higher ACM than those receiving a DOAC, but this was not significant in the adjusted risk factor analysis. Risk factors for ACM following bleeding included age ≥80, and a history of current smoking, myocardial infarction, congestive heart failure, peripheral artery disease, Stage 4 or 5 kidney disease, metastatic cancer, and intracranial haemorrhage. Age<60, bleeding following major trauma, and a history of anaemia were associated with lower risk of ACM (Table 2). Conclusions There is a significant incidence of ACM following MB among FXai users. The incidence rate of ACM in patients treated with FXai was highest in the first month after FXai initiation, declined during the first year and then plateaued. Multiple risk factors associated with ACM have been recognised and these could guide urgent therapies such as antidotes.

Unraveling the thrombin–Alzheimer’s connection: Oral anticoagulants as potential neuroprotective therapeutics

In Alzheimer’s disease (AD), toxic amyloids formed by amyloid-β (Aβ) proteins and tau are implicated in the development of inflammatory, vascular, and neurodegenerative brain disorders. Thrombin has also been recognized as a proteopathic factor involved in Aβ-induced neurovascular dysfunction. Vascular Aβ activates the contact system in the blood, stimulating the production of inflammatory bradykinin and procoagulant thrombin. Thrombin, in turn, triggers inflammation, platelet activation, and the formation of fibrinolysis-resistant, Aβ-containing fibrin clots, leading to Aß-type cerebral amyloid angiopathy and associated neuropathology. Targeting thrombin with oral anticoagulants can normalize proinflammatory and prothrombotic states, counteracting the neurovascular consequences of AD. Pre-clinical studies have shown that such interventions preserve vascular and blood–brain barrier integrity, improve cerebral blood flow and brain perfusion, and reduce parenchymal accumulations of toxic Aβ, tau, fibrin(ogen), and thrombin. These effects mitigate neuroinflammatory and neurodegenerative processes, ultimately preserving cognitive functions for a longer period. Recent observational clinical studies in patients with atrial fibrillation (AF) demonstrated that treatment with direct oral anticoagulants (DOACs) or vitamin K antagonists (VKAs) reduced the risk of dementia by up to 48% compared to non-users. The anti-dementia effects were most prominent in elderly patients but were also observed in individuals with low AF risk or newly diagnosed AF. In addition, DOACs reduced the risk of intracranial hemorrhage by approximately 50% compared to VKAs. The current review highlights the potential neuroprotective role of DOACs in AD. By preventing excessive thrombin generation caused by Aβ pathology, DOACs could protect vascular and neuronal functions, thereby slowing cognitive decline. DOACs, such as dabigatran, apixaban, and rivaroxaban, warrant further clinical investigation for their potential repurposing as disease-modifying therapeutics in AD.

Patients treated with vitamin K oral anticoagulants in family practice: a new approach to bleeding risk assessment. An ancillary study by the CACAO prospective general practice cohort.

The ability of bleeding risk scores to predict major bleeding (MB) or clinically relevant nonmajor bleeding (CRNMB) remains a topic of contention, particularly in nonselected patients in family practice. In addition, the capacity to predict bleeding risk using simple variables has yet to be established. The main objective was to confirm that severe anemia was the most predictive factor for the estimation of bleeding risk in patients treated with vitamin K antagonists (VKAs). Secondary objectives were to test the capacity of different bleeding scores to detect high-risk patients. Subsequently, the impact of functional decline on bleeding incidence was explored. The CACAO study was a multicenter prospective cohort study of patients who, due to nonvalvular atrial fibrillation (NVAF) and/or venous thromboembolism (VTE), had been prescribed an oral anticoagulant by their general practitioner (GP) as a prophylactic measure. Patient characteristics were collected at the time of inclusion by GPs, who then monitored them in accordance with standard practice for one year. MB and CRNMB were the main outcomes for one year. By applying this approach, a total of 13 scores were analyzed. Aaemia was found to be strongly associated with MB (HR: 2.77, 95% CI: 1.2-6.36), with a particularly pronounced association observed in cases of severe anemia (HR: 12.9, 95% CI: 2.76-60.35). Twelve out of 27 MB cases were not identified by at least half of the scores. By contrast, functional decline was identified as a novel factor associated with MB (HR: 2.45, 95% CI: 1.13-5.31). Preexisting anemia is a major prognostic factor associated with the occurrence of bleeding. It seems relevant to suggest that functional decline should be considered by GPs when assessing bleeding risk.

Clinical Efficacy and Safety of Novel Anticoagulants for the Management of Venous Thromboembolism in Patients with Cancer: A Systematic Review and Meta-Analysis.

Cancer patients face a four- to sevenfold higher risk of venous thromboembolism (VTE) than the general population. Novel oral anticoagulants (NOACs) provide convenient alternatives to traditional therapies. We performed a systematic literature search across PubMed, Embase, and the Cochrane Library, targeting studies that examined the use of NOACs in cancer-associated VTE. The search included randomized controlled trials (RCTs). Selected studies compared NOACs with low-molecular-weight heparin (LMWH) or vitamin K antagonists (VKA) in cancer patients diagnosed with VTE. A meta-analysis using a random-effects model was applied to estimate pooled effect sizes for outcomes. In this meta-analysis, we included 12 RCTs. Results showed NOACs were more effective than LMWH in preventing VTE recurrence (RR 0.66, 95% CI 0.52-0.83, p = 0.0004). Compared with VKAs, NOACs showed no significant difference (RR 0.63, 95% CI 0.34-1.15, p = 0.13). However, this finding is limited by the small patient sample. Major bleeding outcomes were similar between NOACs and LMWH/VKAs (RR 1.24, 95% CI 0.85-1.80, p = 0.28; RR 0.77, 95% CI 0.39-1.53, p = 0.46, respectively). Meta-regression analysis indicated a statistically significant positive correlation between mortality and major bleeding events when comparing NOACs with LMWH (p = 0.049). There was no significant difference in all-cause mortality between patients treated with NOACs and those treated with LMWH (RR 1.04, 95% CI 0.92-1.18, p = 0.54) or VKAs (RR 0.94, 95% CI 0.72-1.23, p = 0.65). Meta-analysis shows NOACs, especially factor Xa inhibitors, reduce VTE recurrence in cancer patients more effectively than LMWH. Comparison between NOACs and VKAs is inconclusive due to limited patient data. Further research is needed to assess NOACs' efficacy and safety against VKAs.

Efficacy and safety of different oral anticoagulants for stroke prevention in older patients with atrial fibrillation: A network meta-analysis.

Various oral anticoagulants have been used for stroke prevention in older patients with atrial fibrillation (AF). However, the optimal anticoagulants for stroke prevention has not yet been developed. We performed a systematic review and network meta-analysis to determine the optimal instructions. We searched for randomized controlled trials (RCTs) from PubMed, Embase, and the Cochrane Library without restriction for publication date or language at January 2024. Any RCTs that compared the effectiveness of a direct oral anticoagulant and a vitamin K antagonist (VKA) for stroke prevention in older patients with AF were included in this network meta-analysis. The Bayesian network meta-analysis used a random effects model and surface under the cumulative ranking curve analysis to rank results. All analyses were done using R software with gemtc package, with statistical significance set at P < .05. We included 7 RCTs (79,003 patients) comparing 8 different instructions including Apixaban 5 mg, Dabigatran 110 mg, Dabigatran 150 mg, Edoxaban 30 mg, Edoxaban 60 mg, Rivaroxaban 15 mg, Rivaroxaban 20 mg, and VKA. Apixaban 5 mg, Dabigatran 110 mg, and Dabigatran 150 mg was more effective than the VKA for reducing stroke or systemic embolism risks, and the difference was statistically significant (P < .05). Apixaban 5 mg, Dabigatran 110 mg, Dabigatran 150 mg, Edoxaban 30 mg, and Edoxaban 60 mg was associated with a reduction of the intracranial hemorrhage rate than the VKA (P < .05). The surface under the cumulative ranking curve shows that Dabigatran 110 mg ranked first for reducing stroke or systemic embolism risks. Edoxaban 60 mg ranked first for major bleeding. Dabigatran 110 mg ranked first for intracranial hemorrhage. Apixaban 5 mg ranked first for all bleeding events. Direct oral anticoagulants were found to have lower rates of thromboembolic events compared to VKAs in older patients with AF. Apixaban 5 mg, Dabigatran 110 mg, Dabigatran 150 mg, Edoxaban 30 mg, and Edoxaban 60 mg were also associated with a reduction of intracranial hemorrhage than VKA.

Safety and Effectiveness of Oral Anticoagulants in Atrial Fibrillation: Real-World Insights Using Natural Language Processing and Machine Learning.

Background/Objectives: We assessed the effectiveness and safety of vitamin K antagonists (VKAs) versus direct oral anticoagulants (DOACs) in patients with atrial fibrillation (AF) using artificial intelligence techniques. Methods: This is a retrospective study in 15 Spanish hospitals (2014-2020), including adult AF patients with no history of anticoagulation, thrombosis events, rheumatic mitral valvular heart disease, mitral valve stenosis, or pregnancy. We employed EHRead® technology based on natural language processing (NLP) and machine learning (ML), along with SNOMED-CT terminology, to extract clinical data from electronic health records (EHRs). Using propensity score matching (PSM), the effectiveness, safety, and hospital mortality of VKAs versus DOACs were analyzed through Kaplan-Meier curves and Cox regression. Results: Out of 138,773,332 EHRs from 4.6 million individuals evaluated, 44,292 patients were included, 79.6% on VKAs and 20.4% on DOACs. Most patients were elderly [VKA 78 (70, 84) and DOAC 75 (66, 83) years], with numerous comorbidities (75.5% and 70.2% hypertension, 47.2% and 39.9% diabetes, and 40.3% and 34.8% heart failure, respectively). Additionally, 60.4% of VKA and 48.7% of DOAC users had a CHA2DS2-VASc Score ≥4. After PSM, 8929 patients per subgroup were selected. DOAC users showed a lower risk of thrombotic events [HR 0.81 (95% CI 0.70-0.94)], minor bleeding [HR 0.89 (95% CI 0.83-0.96)], and mortality [HR 0.80 (95% CI 0.69-0.92)]. Conclusions: Applying NLP and ML, we generated valuable real-world evidence on anticoagulated AF patients in Spain. Even in complex populations, DOACs have demonstrated a better safety and effectiveness profile than VKAs.

Safety and efficacy of direct oral anticoagulants in chronic kidney disease: a meta-analysis

BackgroundDirect oral anticoagulants (DOACs) have emerged as the first-line therapy for venous thromboembolism and stroke prophylaxis in atrial fibrillation. As DOACs are partially excreted renally, their safety in patients with chronic kidney disease (CKD) is unclear. ObjectivesTo synthesize primary evidence on the safety profile of DOACs in patients with CKD. MethodsWe searched MEDLINE and Embase from inception to June 2023 for randomized and nonrandomized cohort studies comparing DOACs with vitamin K antagonists (VKAs) in CKD patients. Screening and data collection were conducted in duplicate. The primary safety outcome was major bleeding, defined by International Society on Thrombosis and Haemostasis criteria, stratified by CKD severity. Meta-analysis was done using the Mantel–Haenszel random-effects model, presented as odds ratios (ORs) with corresponding 95% CIs. ResultsOf the 2355 articles captured in the literature search, 25 nonrandomized studies (n = 6832) and 6 randomized studies (n = 66,898) were included. DOACs reduced major bleeding compared with VKAs in all subgroups (stage 4: OR, 0.73; 95% CI, 0.58, 0.93; stage 5/renal replacement therapy: OR, 0.70; 95% CI, 0.50, 0.98; stage unspecified: OR, 0.72; 95% CI, 0.63, 0.83). Apixaban and rivaroxaban both reduced major bleeding in stage 5/renal replacement therapy patients (apixaban: OR, 0.66; 95% CI, 0.52, 0.85; rivaroxaban: OR, 0.58; 95% CI, 0.35, 0.94). ConclusionIn this meta-analysis, DOACs reduced major bleeding compared with VKAs in stage 4, stage 5/renal replacement therapy, and CKD stage unspecified patients. Future analysis should evaluate the impact of specific DOACs and dosage on safety and efficacy in this population.

Assessment of bleeding events in patients receiving DOACs with or without statins to treat venous thromboembolism: insights from the RIETE registry

ObjectiveTo evaluate the impact of coadministering statins with direct oral anticoagulants (DOACs) on the risk of major bleeding events in patients with venous thromboembolism (VTE).DesignObservational cohort analysis based on a...

CytoSorb hemoadsorption of apixaban during cardio-pulmonary bypass for heart transplantation

IntroductionHeart transplantation is an emergency surgery requiring cardio-pulmonary bypass (CPB) and its timing is unpredictable. Patients on the transplant waiting list often have multiple reasons for being anticoagulated. Direct oral anticoagulants (DOACs) such as apixaban are very popular due to their well-known advantages. Intraoperative removal of apixaban using CytoSorb® (CytoSorbents Inc., Princeton, NJ, USA), seems to be an interesting solution for patients on DOACs requiring an emergency CPB intervention. The aim of this short communication is to describe the perioperative effects of the use of the CytoSorb® hemoadsorption device during emergency CPB for a heart transplant patient Case presentationA 61-year-old male patient (75kg/173cm) wait-listed for heart transplantation was admitted to our hospital (Pitié-Salpêtrière Hospital, Sorbonne University, Paris, France) to benefit from a heart transplantation. This patient, with many comorbidities, has an end-stage heart failure with multiple episodes of decompensation over the previous year. He was anticoagulated with a Vitamin K antagonist (VKA) due to atrial fibrillation and was switched to apixaban (5mg twice daily) 9 days before surgery based on poor clotting control. A NaCl 0.9% primed CytoSorb cartridge was inserted into the CPB circuit. Hemoadsorption was performed during the entire CPB duration. Anti-Factor Xa Activity (AFXaA) levels were taken at multiple time points before, during and after surgery in order to monitor anticoagulation. Results. Preoperatively, activated Clotting Time (ACT) was 146 seconds. The ACT reached 545 seconds after administration of 25,000IU of unfractionated heparin (UFH). Surgery consisted of an orthotopic heart transplantation with bi-caval anastomoses.CPB duration was 133 minutes with 83 minutes of aortic cross clamping. Total graft ischemic time was 249 minutes. At the time of anesthesia induction and after UFH administration, AFXaA levels were 330ng/mL and 317ng/mL, respectively. Thereafter, AFXaA decreased to 137ng/mL during CPB and to 57ng/mL after the end of CPB and 250mg (=25,000IU) of protamine administration.After surgery, AFXaA levels stabilized over 50ng/mL over the next 14 hours. Postoperative anticoagulation was performed with the use of UFH starting 6 hours after surgery.No primary graft dysfunction (PGD) was observed, and during the post-operative period of 72 hours, the patient did not have any bleeding events requiring reintervention or transfusion. ConclusionIn conclusion, we observed that CytoSorb® could be a potential solution to remove apixaban intraoperatively. If this efficacy is confirmed in larger trials, it would allow transplant candidates to be treated with DOACs without requiring a switch to VKAs.

Dental Extractions In Patients Under Vitamin-K Antagonists in Morocco

Dental Extractions In Patients Under Vitamin-K Antagonists in Morocco

RARE CASE OF SPONTANEOUS HEMOPERICARDIUM IN A PATIENT RECEIVING APIXABAN: CASE REPORT

Apixaban is a new oral anticoagulant (NOAC) available since 2012, indicated particularly for the prevention of embolic events in patients with non-valvular atrial fibrillation [1]. It is a direct inhibitor of factor Xa, with a half-life of around 12 hours. This new anticoagulant is associated with a lower risk of bleeding than vitamin K antagonists (VKAs) such as warfarin and requires less monitoring [2]. However, several recently published cases have demonstrated a correlation between Apixaban and the occurrence of pericardial effusion. We report the case of a 75-year-old hypertensive man diagnosed with atrial fibrillation 3 months ago, treated with Apixaban 5mg twice daily. He presented to the emergency department with rapidly worsening dyspnea, and echocardiography revealed a large pericardial effusion requiring drainage. A full etiological work-up was carried out, revealing no underlying pathology or triggering event to explain his pericardial effusion. We believe that his recently introduced anticoagulant therapy is the true cause.

Safety of Sofosbuvir-Based Direct-Acting Antivirals for Hepatitis C Virus Infection and Direct Oral Anticoagulant Co-Administration.

Background: Direct oral anticoagulants (DOACs) are recommended for the management of thrombosis prophylaxis, especially in patients with atrial fibrillation. As substrates of cytochrome P450 (CYP) 3A4 and/or P-glycoprotein, they are implicated in potential drug-drug interactions. NS5A/NS5B inhibitors are direct-acting agents (DAAs) against the Hepatitis C Virus (HCV) infection that exert a mild inhibition of P-glycoprotein without effects on CYP3A4. A DOAC and NS5A/NS5B inhibitor co-administration may lead to an increased risk of bleeding. Real-world data on the concomitant use of DOACs and DAAs are scarce. On this purpose, we perform a retrospective analysis on the risk of vascular adverse events (bleeding and thrombosis) among HCV patients under DOAC/DAA therapy, even in advanced liver disease. Methods: Between May 2015 and April 2023, patients treated with sofosbuvir-based DAA regimens and DOACs were consecutively included in this study from 12 Italian medical centers. Baseline characteristics, especially concerning bleeding risk and liver function, were collected. The occurrence of bleeding events, classified as major and minor, was the primary endpoint. Secondary endpoints were the rate of any thrombotic events and/or the need for discontinuation of one or both treatments. Moreover, a cohort of patients, matched by demographic characteristics (age and sex), that switched to vitamin K antagonists (VKAs) during the antiviral treatment was compared with the DOAC/DAA group. Results: A total of 104 patients were included. Thirty-eight of them (36.5%) were cirrhotic. Atrial fibrillation was an indication for anticoagulation in almost all cases (76%). Rivaroxaban (35.6%) was the most used DOAC, followed by apixaban (26.9%), dabigatran (19.2%) and edoxaban (18.3%). Sofosbuvir/velpatasvir (78.8%) was the most prescribed DAA, and all patients were already on anticoagulant therapy before the start of DAAs. During concomitant DOAC/DAA treatment, no major bleeding events were recorded, while four minor bleeding events occurred, but none resulted in DAA or DOAC discontinuation. At univariate analysis, the only additional risk factor statistically related to bleeding events was the anticoagulant therapy (hazard ratio [HR]: 13.2, 95% confidence interval 1,6-109). Performing an evaluation by a LOGIT binomial analysis with demographic characteristics, the antiplatelet therapy remained statistically associated to bleeding events. No significant differences were found in the rate of clinically relevant bleeding when the main population was compared with the VKA-switched cohort. A single major bleeding event leading to anticoagulation and DAA discontinuation was reported in VKA-switched matched cohort. Conclusions: In our study, the concomitant use of NS5A/NS5B inhibitors with DOAC showed good safety, and the only risk factor associated with bleeding events was the concomitant antiplatelet therapy. These findings support the use of DOACs during sofosbuvir-based HCV treatment, even in advanced liver disease. Replacing DOACs with VKAs does not appear to be of clinical benefit.

Antithrombotic Strategies After Transcatheter Aortic Valve Replacement in Patients Without an Indication of Oral Anticoagulants: A Network Meta-Analysis of Randomized Controlled Trials.

Single-antiplatelet therapy (SAPT) has been a standard of care posttranscatheter aortic valve replacement with no clear evidence exist using direct oral anticoagulants (DOACs), vitamin K antagonists (VKA), or dual antiplatelet agents (DAPT); thus we aim to compare the safety and efficacy of the various antithrombotic strategies after transcatheter aortic valve replacement. We performed a network meta-analysis using a frequentist framework, pooling dichotomous outcomes using risk ratio (RR), and continuous data using mean difference, along with the corresponding 95% confidence interval (CI). Nine randomized controlled trials with 4193 patients were included, 567 patients were in the VKA group, 591 patients in the SAPT group, 1571 patients in the DAPT group, and 1464 patients in the DOACs group. Only DOAC showed a statistically significant higher risk of all-cause mortality [RR of 1.88 (95% CI: 1.07-3.28)] with no statistically significant difference between our arms in terms of mortality. For minor bleeding, DAPT had a significant higher risk with RR of 1.53 (95% CI: 1.04-2.25), while for major bleeding, DAPT and DOAC had a significant higher risk with RR of 2.36 (95% CI: 1.27-4.40) and 4.74 (95% CI: 2.05-10.92), respectively. There was no significant difference in terms of stroke and life-threatening bleeding. Moreover, only DOAC showed a significantly lower risk for valve thrombosis, when compared to other strategies [RR: 0.24 (95% CI: 0.13-0.46)]. Overall, SAPT had lower major bleeding events compared to other arms. There were no differences in the outcomes of stroke, myocardial infarction, or life-threatening bleeding outcomes. However, DOACs significantly reduced valve thrombosis compared to VKAs.

A new strategy for monitoring of direct oral anticoagulants in patients with cyanotic and complex congenital heart disease

BackgroundPatients with congenital heart disease (CHD) often require an oral anticoagulation. Vitamin K antagonists (VKA) are the standard treatment, however, an increased hematocrit in patients with secondary erythrocytosis due to cyanosis complicates the correct measurement of the international normalized ratio. Direct oral anticoagulants (DOAC) could be an alternative, but data on their efficacy and safety in complex and cyanotic CHD patients are scarce. This study proposes a new strategy of DOAC monitoring in these patients using D-dimers and DOAC trough levels. MethodsThis is a retrospective study including cyanotic and complex CHD patients requiring oral anticoagulation. Clinical, cardiac imaging and laboratory data were collected before and after start of DOAC. The new monitoring strategy consists of determination of D-dimers and DOAC trough levels at 1–4 weeks, 1–6 months, 6–12 months, >1 year after start of DOAC. ResultsEleven patients were included. For 10 patients D-dimers and DOAC trough levels were in target range. In one patient, D-dimers increased continuously after start of DOAC despite dose escalation, suggesting insufficient DOAC efficacy and finally requiring a switch to VKA. D-dimers subsequently decreased under VKA to the therapeutic range. In three patients, one thromboembolic and two minor bleeding complications occurred. No major complications were observed. ConclusionsWe propose a new strategy of monitoring of oral anticoagulation with DOAC and report its implementation in clinical routine. Highlighting the importance of pharmacokinetic and -dynamic monitoring, this strategy could improve safety and efficacy of DOAC in cyanotic and complex CHD which, however, requires a prospective validation.

Long‐term cognitive function changes with non‐vitamin K oral anticoagulants in older patients with atrial fibrillation. A multicenter cohort study

AbstractBackgroundAtrial fibrillation is associated with several comorbidities, particularly cognitive impairment and dementia, especially in older patients. Non‐vitamin K oral anticoagulants (NOACs) or vitamin K antagonists (VKAs) were used to prevent thromboembolic events. However, data on the real benefit of these drugs on cognitive function decline remains controversial. In this study we evaluated the effect of NOACs compared to VKAs on the absolute and relative decline in cognitive function over time.MethodsNine hundred and eighty‐three older patients with nonvalvular AF were enrolled (76 ± 6 years; 291 on VKAs and 692 on NOACs). The cognitive function was assessed with Mini Mental State examination (MMSE) score. The between‐arms difference of cognitive evolution over time was investigated by Linear Mixed Models and group‐based trajectory model analyses.ResultsIn the whole multicenter observational study, after a long follow‐up of 7.2 ± 3.4 years, the patients of the NOACs versus VKAs group had lowest absolute reduction of the MMSE score between baseline and follow‐up (−0.3 ± 0.03 vs.−1.7 ± 0.1, p &lt; 0.001). After stratification into five subgroups according to trajectories of MMSE score over time, the probability to belong to trajectories with lower decline in cognitive functions was higher in patients on NOACs than in those on VKAs (3.93–13.88 times).ConclusionIn older patients with atrial fibrillation, the use of NOACs was associated with a smaller decline of cognitive function over time compared to the VKAs, regardless that patients in the NOACs group were older and with a higher burden of comorbidities.