Vitamin K Antagonists Research Articles

Machine learning approach for prediction of outcomes in anticoagulated patients with atrial fibrillation

Abstract Background Despite the availability of different risk scores, the accuracy of actual prediction tools for outcomes in patients with atrial fibrillation (AF) remains modest [1]. Although Machine Learning (ML) has been used to predict outcomes in the AF population, evidences about outcome prediction in a population entirely on oral anticoagulation is lacking. The aim of this study is to use ML to predict outcomes in anticoagulated patients with atrial fibrillation, processing data from the Italian AF START-2 Register. Methods and aims Different ML models were applied to predict all-cause death, cardiovascular (CV) death, major bleeding and stroke in anticoagulated patients with nonvalvular AF. Overall population, Vitamin K Antagonists (VKA) and Direct Oral Anticoagulants (DOACs) populations were considered for the analyses. Results 11078 AF patients (male n=6029, 54.3%) were enrolled with a median follow-up period of 1.5 years [IQR 1.0-2.6]. Patients on VKA were 5135 (46.4%), while 5943 (53.6%) were on DOACs. During the follow-up, 785 patients died, of which 169 (21.6%) due to CV causes; 240 major bleeding events were recorded, and 50 strokes occurred. Using Multi-Gate Mixture of Experts (MmoE), a cross-validated AUC of 0.779 ± 0.016 and 0.745 ± 0.022 were obtained, respectively, for the prediction of all-cause death and CV death in the overall population. The best ML model outperformed CHA2DSVA2SC and HAS-BLED for all-cause death prediction (p<0.001 for both). When compared to HAS-BLED, Gradient Boosting improved major bleeding prediction in DOACs patients compared to HAS-BLED score (0.711 vs. 0.586, p<0.001). Body mass index, age, glomerular filtration rate, platelet count and hemoglobin levels resulted the most important variables for ML prediction. Conclusions In patients with AF, ML models showed good discriminative ability to predict all-cause death, regardless of the type of anticoagulation strategy, and major bleeding on DOAC therapy, outperforming CHA2DS2VASC and the HAS-BLED scores for risk prediction in these populations. Anemia, platelet count, and BMI emerged as new potential risk predictors in anticoagulated AF patients. The applications of ML prediction models in clinical practice could improve the risk assessment and subsequent management of anticoagulated patients with AF.Graphical AbstractFeature importance for Bleeding in DOACs

Patient-reported treatment burden: comparison between vitamin-K antagonist and non-vitamin K antagonist oral anticoagulants

Abstract Introduction Treatment burden (TB) is defined as the overall workload that maintenance or improvement of their functioning and well-being poses on patients with chronic medical conditions. A high patient-reported TB has been associated with lower adherence to treatment and increased risk of major adverse events including death. We explored the differences in patient-reported TB value and prevalence of unacceptably high TB score (≥59 points) between patients receiving vitamin K antagonist oral anticoagulants (VKA) and non-vitamin K antagonist oral anticoagulants (NOAC). Furthermore, we explored contributory factors associated with TB and the relationship between TB and quality of life (QoL) in these patients. Methods A single-centre study included consecutive adult in- and outpatients on long-term oral anticoagulation, seen at a university clinical centre a from April to June 2019, who were willing to complete the Treatment Burden Questionnaire encompassing 13 items assessing the TB associated with taking medicine, self-monitoring, laboratory assessments, medical consultations, organisational and administrative requirements, adherence to dietary and physical activity recommendations, as well as the social repercussions of the treatment. Results Of 320 enroled patients, 206 (64.4%) were taking a VKA. Atrial fibrillation was the most common indication for long-term oral anticoagulation (n=299, 93.4%). The mean TB score was significantly higher in patients on VKA versus those taking a NOAC (48.8 ±26.5 vs. 41.8 ±19.7, P= 0.014), mostly owing to significantly higher TB values for questions related to self-monitoring, including the International Normalized Ratio (INR) control (3.85±3.32 vs. 1.62±1.38, P<0.001) and diet restrictions (3.98±3.43 vs. 2.48±2.49, P<0.001) in patients taking VKA (Figure 1). In addition, these patients significantly more often reported an unacceptably high TB of ≥59 points compared with those taking NOAC (30.1% vs 18.4%, P= 0.024). Multivariable regression analysis of predictors of TB in patients taking a VKA or NOAC are presented in Table 1. Conclusion In our study, patients receiving a VKA reported significantly higher TB compared to those using NOAC, especially regarding the questions about self-monitoring (including INR control) and diet restrictions. An unacceptably high TB was also more prevalent among patients receiving a VKA. Our findings suggest that prescribing NOACs in preference to VKAs could help in decreasing the self-reported TB in patients who need oral anticoagulant therapy.

Exploring the Perioperative Use of DOACs, off the Beaten Track.

A notable increase in direct oral anticoagulant (DOAC) use has been observed in the last decade. This trend has surpassed the prescription of vitamin K antagonists (VKAs) due to the absence of the need for regular laboratory monitoring and the more favorable characteristics in terms of efficacy and safety. However, it is very common that patients on DOACs need an interventional or surgical procedure, requiring a careful evaluation and a challenging approach. Therefore, perioperative anticoagulation management of patients on DOACs represents a growing concern for clinicians. Indeed, while several surgical interventions require temporary discontinuation of DOACs, other procedures that involve a lower risk of bleeding can be conducted, maintaining a minimal or uninterrupted DOAC strategy. Therefore, a comprehensive evaluation of patient characteristics, including age, susceptibility to stroke, previous bleeding complications, concurrent medications, renal and hepatic function, and other factors, in addition to surgical considerations, is mandatory to establish the optimal discontinuation and resumption timing of DOACs. A multidisciplinary approach is required for managing perioperative anticoagulation in order to establish how to face these circumstances. This narrative review aims to provide physicians with a practical guide for DOAC perioperative management, addressing the most controversial issues.

Ultrasound-guided venipuncture of femoral veins vs standard palpation approach in patients undergoing pulmonary veins isolation

Abstract Introduction Complications related to vascular access frequently arise during transcatheter atrial fibrillation (AF) ablation. Vascular access related complications remain the main cause of procedure related adverse events. In the literature, there is no clear evidence supporting the benefit of ultrasound-guided (USG) vascular access. Purpose We hypothesized that USG venipuncture could reduce vascular complication rates and reduce the need for additional interventions due to complications related to vascular access. Methods We conducted a single-center retrospective study. The primary endpoint was the rate of major complications, defined as arteriovenous fistula, pseudoaneurysm, and groin hematoma with Bleeding Academic Research Consortium (BARC) classification ≥ 2 requiring interventions such as transfusions or surgical/percutaneous repair and/or resulting in hospital prolongation or readmission). The secondary endpoints were the rate of minor complications, defined as groin hematoma with BARC classification = 1 or bleeding without sequelae, and the composite rate of additional non-scheduled exams and procedures due to vascular complications. The study included all patients who underwent atrial fibrillation ablation with radiofrequency (RF) between January 2020 and December 2022 in our center, performed by two expert operators: one utilizing a classic palpation (BLIND) approach and the second one employing the USG approach. Identical materials were used for access in both groups, and the choice of protamine administration or closure method was decided by the operator on a case by case basis. In total, there were 946 patients, 352 in USG group and 594 in BLIND group. For patients in both groups who were on vitamin K antagonists (VKAs), uninterrupted administration with an international normalized ratio (INR) ratio between 2.0 and 3.0 was required. Results Major complications were significantly reduced in the USG group compared to the BLIND group (0 (0%) in USG vs. 9 (1.5%) in BLIND, P = 0.02). No significant difference was observed in minor complications between the two groups (3 (0.8%) in USG vs. 6 (1.0%) in BLIND, P = 0.809). During hospitalization or readmission, 3 additional non-scheduled exams/procedures were required (3 vascular echos) in the USG group, while 33 were needed in the BLIND group (23 vascular echos, 6 thrombin injections, 2 surgical procedures and 2 CT-Angio) with a significative reduction (P 0.034). Conclusions USG venipuncture was associated with a reduction in major complication rates and a decrease in additional exams required during hospitalization or readmission. However, it did not lead to a reduction in minor complications. These findings support the use of ultrasound in AF ablation procedures to avoid access related complications requiring intervention.Baseline CharacteristicsSummary

Comparative effectiveness of different management strategies for left atrial appendage thrombus in patients on optimal NOAC therapy

Abstract Background Left atrial appendage (LAA) thrombus is the primary cause of stroke and systemic embolism in atrial fibrillation (AF). Novel oral anticoagulants (NOACs) effectively reduce the prevalence of LAA thrombosis and stroke risk. Nonetheless, there is no clear advice for patients with a NOAC-resistant thrombus, necessitating individualized decision-making without strong support of the current guidelines. Aims To analyze patients diagnosed with an LAA thrombus despite adequate NOAC therapy and to compare the efficacy of various therapeutic strategies in achieving thrombus resolution. Methods We retrospectively analyzed patients scheduled for cardioversion or catheter ablation of AF between 2014 and 2023 who were diagnosed with LAA thrombus despite being on optimal NOAC therapy. These patients underwent follow-up transesophageal echocardiography (TEE) or cardiac CT angiography. Changes in treatment modalities were divided into four groups: transition to an alternative NOAC, switch to a vitamin K antagonist (VKA), the addition of an antiplatelet agent, or the deliberate maintenance of the current treatment. Results We analyzed the data of 90 patients comprising 103 cycles of treatment. The patients were either on rivaroxaban (41%), apixaban (32%), dabigatran (15%) or on edoxaban (12%) at the time of the initial TEE. A change to a different NOAC was observed in 37% of cases, transition to a VKA in 22%, supplementation with antiplatelet therapy in 16%, while deliberate absence of treatment modification in 25% of cases. Subsequent follow-up TEE (or CT angiography in a minority of cases) was performed at a median of 68 [43 – 94] days from the baseline evaluation. Successful thrombus resolution was achieved in 72% of cases. Evaluation of therapeutic strategies revealed that any modification of treatment was three times more effective than deliberate no change in treatment; thrombus resolution was observed in 60 (81%) vs. 17 (59%) cases (OR 3.03 [1.18 - 7.75], p = 0.021). Nevertheless, no particular strategy demonstrated superior efficacy over others. Conclusions Resolution of LAA thrombus in patients already on adequate NOAC treatment may require a revision of the prior anticoagulation strategy; however, none of the commonly employed strategies appears to exhibit distinct superiority over the rest.

#280 Effectiveness and safety of direct oral anticoagulants vs VKA in patients on chronic dialysis: a target trial emulation using nationwide registry data

Abstract Background and Aims The mortality and morbidity rates among patients on dialysis remain high and cardiovascular disease is the leading cause of death in this population. In chronic kidney disease (CKD), a major thromboembolic risk is paradoxically associated with a major haemorrhagic risk. Hence, the prescription of oral anticoagulants in CKD patients is challenging. Clinical trials of direct oral anticoagulants (DOAC) are scarce and inconclusive in patients who are receiving dialysis, for whom DOAC are not labelled in Europe. In an exhaustive French nationwide registry of patients undergoing chronic dialysis, we compared the effectiveness and safety of off-label DOAC use versus approved vitamin K antagonist (VKA). Method Data on patients on dialysis were extracted from the French Renal Epidemiology and Information Network (REIN) registry and merged with data from the French national healthcare system database (Système National des Données de Santé, SNDS). Patients on dialysis who had initiated treatment with an oral anticoagulant between January 1st, 2012, and December 31st, 2020, were eligible for inclusion. The primary safety outcome was the occurrence of major bleeding events and the primary effectiveness outcome was the occurrence of thrombotic events. Using target trial emulation design, we compared the safety and effectiveness outcomes for DOAC and VKA using propensity-score-weighted cause-specific Cox regression. Results 8 954 patients received an oral anticoagulant (483 DOAC and 8 471 VKA) for the first time after the initiation of dialysis. Over a median [interquartile range] follow-up period of 1.7 [0.8-3.2] years, 2 567 patients presented a first thromboembolic event and 1 254 patients had a bleeding event. After propensity score adjustment, the risk of a thromboembolic event was significantly lower in patients treated with a DOAC than in patients treated with a VKA (weighted hazard ratio (HR) [95% confidence interval (CI)]: 0.66 [0.46; 0.94] (Figure). A non-significant trend toward lower risk of major bleeding events was found in patients treated with a DOAC compared to patients treated with a VKA (weighted HR [95% CI]: 0.68 [0.41; 1.12]) (Figure). Sensitivity analyses showed the same trends. Conclusion The fact that patients on dialysis are excluded from large, cardiovascular-disease-focused randomized controlled trials (such as those with DOACs) significantly limits the evidence needed to make clinical decisions. Most of the retrospective cohort studies comparing these two drug classes were performed in the USA, where, in contrast to Europe, apixaban has been approved for the treatment of non-valvular fibrillation in patients on haemodialysis. Our real-world study of patients on dialysis is one of the first of its type to have assessed the effectiveness and safety of off-label DOAC prescription (relative to VKA prescription) in Europe. In a large group of dialysis patients initiating oral anticoagulation, the off-label use of DOACs was associated with a statistically significant lower risk of thromboembolic events, and a non-significant trend toward lower risk of bleeding relative to VKA use. These results are reassuring with regard to the off-label use of DOACs and might facilitate the establishment of an expert consensus and guidelines on antithrombotic therapy in patients with ESKD.

The impact of different anticoagulants and antiplatelets regimens on acute epistaxis outcomes

BackgroundThe impact of anticoagulants (AC) and antiplatelets (AP) on the management of acute epistaxis remains unclear. This study investigated the association between AC/AP therapy and treatment outcomes in patients with acute epistaxis.MethodologyA retrospective analysis of patients presented to the otolaryngology emergency room with acute epistaxis (2014–2022). Patients were categorized based on their regular medications: AP, dual AP therapy (DAPT), new oral anticoagulants (NOAC), vitamin K antagonists (VKA), or no regular AC/AP use (control group). Outcome measures included rates of minor interventions (chemical or electrical cautery, nasal tamponade), major interventions (endoscopic ligation, embolization), recurrent emergency department visits, admission rates, and duration.Results786 patients were included with an average follow-up period of 52.56 ± 20.4 months. Compared to the control group, patients on AP, DAPT, or VKA had significantly higher rates of minor interventions (63.1% vs. 74.4%, 79.6%, and 77.3%, respectively, p < 0.05). DAPT users exhibited a higher rate of major interventions than the control (5.6% vs. 1.3%, p = 0.053). NOAC users showed no significant difference in minor interventions compared to control and required no major interventions. Both NOAC and VKA users had significantly higher rates of recurrent epistaxis events and prolonged hospitalization compared to the control (p < 0.01 and p < 0.05, respectively).ConclusionsNOAC demonstrated more favorable outcomes than VKA in patients with acute epistaxis, and DAPT use was associated with an increased need for major interventions. These findings suggest a more conservative approach in NOAC users than other AC/AP agents.

The historical origins of modern international normalized ratio targets

Prothrombin time (PT) and its derivative international normalized ratio (INR) are frequently ordered to assess the coagulation system. Plasma transfusion to treat incidentally abnormal PT/INR is a common practice with low biological plausibility and without credible evidence, yet INR targets appear in major clinical guidelines and account for the majority of plasma use at many institutions. In this article, we review the historical origins of INR targets. We recount historical milestones in the development of the PT, discovery of vitamin K antagonists (VKAs), motivation for INR standardization, and justification for INR targets in patients receiving VKA therapy. Next, we summarize evidence for INR testing to assess bleeding risk in patients not on VKA therapy and plasma transfusion for treating mildly abnormal INR to prevent bleeding in these patients. We conclude with a discussion of the parallels in misunderstanding of historic PT and present-day INR testing with lessons from the past that might help rationalize plasma transfusion in the future.

Direct oral anticoagulants vs Vitamin-K antagonists in solid organ transplant recipients: A systematic review and meta-analysis.

Oure review aimed to examine evidence on the safety and efficacy of direct oral anticoagulants (DOAC) vs Vitamin K antagonists (VKA) in patients with solid organ transplants. PubMed, Embase, and Web of Science libraries were searched from inception to 25th November 2023 for all studies comparing DOAC with VKA in solid organ recipients. Nine studies were included with patients who had undergone kidney, heart, or liver transplants. Meta-analysis showed that patients receiving DOAC had a significantly reduced risk of composite bleeding as compared to those with VKA (RR: 0.45 95% CI: 0.30, 0.68 I2=25%). However, the risk of major bleeding was not significantly different between the two groups (RR: 0.76 95% CI: 0.40, 1.42 I2=37%). Pooled analysis showed that the risk of VTE (RR: 0.90 95% CI: 0.72, 1.13 I2=0%) and ischemic stroke (RR: 0.87 95% CI: 0.39, 1.94 I2=12%) was not significantly different between DOAC and VKA groups. Limited data shows that DOAC are safe and effective in patients with solid organ transplants. The overall risk of bleeding may be reduced with the use of DOAC. There is a need for randomized controlled trials comparing DOAC and VKA in such patients to obtain high-quality evidence.

Bleeding Outcomes of Direct Oral Anticoagulants and Vitamin K Antagonists for Acute Venous Thromboembolism: A Cross-Sectional Study.

Venous thromboembolism (VTE) is a widespread and significant cause of morbidity and mortality on a global scale. The primary objective of this cross-sectional study is to examine the impact of anticoagulant therapy on major organ hemorrhage events in patients diagnosed with acute venous thromboembolism (VTE). Specifically, this research compares the effects of vitamin K antagonists (VKAs) and direct oral anticoagulants (DOACs). This retrospective observational study examined the medical records of 46 patients who had been diagnosed with VTE and were receiving treatment with DOACs or VKAs. The documentation of patient characteristics encompassed demographic information, comorbidities, and treatment particulars. Within 30 days of hospital admission, the incidence of significant organ bleeding events, with an emphasis on gastrointestinal and intracranial hemorrhage, was the primary outcome evaluated. Overall, 46 patients with VTE who were treated with oral anticoagulation therapy participated in the study. Twenty-four and 22 patients were administered VKAs and DOACs, respectively. The similarity in baseline characteristics between the DOAC and VKA groups ensured that the analyses were well-matched. The examination of bleeding sites unveiled subtle variations, as the DOAC group exhibited a progressive increase in the incidence of intracranial bleeding (12, 55.5%), while the VKA group demonstrated a surge in upper gastrointestinal bleeding (12, 50%) as well. While lacking statistical significance, these observed patterns are consistent with prior research that indicates that DOACs may have a lower risk of catastrophic hemorrhage in comparison to VKAs. The overall in-hospital mortality rate for patients treated with VKA was 33.3% (n=8), while that treated with DOAC was 18.2% (n=4). These differences did not reach statistical significance (P>0.05). In a similar vein, the evaluation of mortality associated with hemorrhage revealed six (25%) in the group receiving VKA and three (13.6%) in the group receiving DOAC; the P value was not statistically significant (P>0.05). This study contributes valuable insights into bleeding outcomes associated with anticoagulant therapy for acute VTE. The nuanced differences in bleeding patterns highlight the complexity of anticoagulant selection, emphasizing the importance of considering bleeding site considerations. The comparable mortality rates support existing evidence regarding the favorable safety profile of DOACs.

Efficacy and safety of Apixaban in the treatment of cerebral venous sinus thrombosis: a multi-center study.

Information regarding the safety and efficacy of specific direct oral anticoagulants (DOAC) in the treatment of cerebral sinus and venous thrombosis (CSVT) is scarce. Apixaban is one of the most frequently prescribed DOACs. Therefore, we aimed to compare the safety and efficacy of Apixaban with those of vitamin k antagonists (VKA) in patients with CSVT. Prospective CSVT databases from seven academic medical centers were retrospectively analyzed. Patients treated with Apixaban were compared to those treated with VKA. Data on demographics, clinical presentations, risk factors, radiological and outcome parameters were studied. Overall, 403 patients were included in the analysis. Of them, 48 (12%) were treated with Apixaban, and 355 (88%) were treated with VKA. Rates of coagulopathies were significantly higher in the VKA-treated patients but no other differences between the groups were found in baseline characteristics and underlying etiology. No significant differences were found between groups in efficacy or safety parameters including the rates of recanalization, favorable outcomes, one-year mortality, seizures, intracranial hemorrhage or CSVT recurrences. Our data suggests that Apixaban may be safe and effective for patients with CSVT. These results should be tested in prospective randomized clinical studies.

BETWEEN SCYLLA AND CHARYBDIS: MULTIPLE LEFT ATRIAL THROMBI DESPITE ORAL ANTICOAGULATION AND ANTIPLATELET THERAPY IN A PATIENT CANDIDATE FOR LEFT ATRIAL APPENDAGE OCCLUSION

Abstract Introduction Left atrial (LA) thrombosis usually occurs in patients affected by atrial fibrillation (AF), generally involving the left atrial appendage (LAA). We present the unexpected echocardiographic finding of multiple LA thrombi despite an adequate antithrombotic strategy. Case Presentation A 76–year–old lady underwent transesophageal echocardiographic examination (TOE) to assess eligibility for percutaneous LAA occlusion (LAAO) procedure due to high bleeding risk. Her medical history included AF and a recent percutaneous coronary revascularization; therefore, her antithrombotic therapy included apixaban 2.5 mg bid and clopidogrel 75 mg od. The TOE showed LA structural and functional remodeling with spontaneous echo contrast and multiple thrombi involving the LAA (one [12 x 9 mm] overflowing the orifice and attached to the Coumadin Ridge and the second [12 x 7 mm] attached and arising from the tunnel of patent foramen ovale). Mitral valve stenosis was excluded (Fig.1). Due to TOE findings, the patient was not considered eligible for percutaneous LAAO. Due to the concomitant very high thromboembolic risk, despite the previous intracranial bleeding, we decided to stop apixaban and to start parenteral anticoagulation for 3 weeks with low–molecular weight heparin (100 UI/kg bid) followed by the switch to a vitamin k antagonist (VKA). We also prescribed a hematological evaluation to exclude a hypercoagulability disorder. Our patient’s daughter was a carrier of a mutation in both the methylenetetrahydrofolatereductase and Thrombin genes. A TOE after 30 days showed the persistence of LA thrombi, although with significantly reduced size and mobility (Fig.2). The follow–up was clinically uneventful. We suggested to continue anticoagulation therapy with VKA, and we planned a new TOE after 4 weeks. Discussion Although proper anticoagulation decreases cardioembolic risk in patients with AF, atrial thrombosis may occur due to LA remodeling, high CHA2DS2–VASc score and other factors, including hypercoagulability disorders. The presence of multiple LA thrombi represents a challenge for clinicians, especially in case of concomitant high thromboembolic and bleeding risk. However, the best treatment strategies for these extreme conditions are not defined, so far. Therefore, the therapeutic choice is often tailored to the single patient and based on the clinical judgment, bearing in mind that avoiding Charybdis means passing to close to Scylla and vice versa.

Is There an Alternative Oral Anticoagulation to Vitamin-K-Antagonists for Patients with Mechanical Aortic Valve Replacement? - A Literature Review.

Current guidelines exclusively recommend vitamin-K-antagonists (VKA) as anticoagulation for patients after mechanical aortic valve replacement due to the increased postoperative risk of valve thrombosis and thrombo-embolism. Strict and regular assessments are mandatory during VKA therapy to ensure a potent anticoagulatory effect within the desired range. From the patients' perspective, VKA are associated with relevant interactions and side effects reducing the quality of life and contributing to a high number of patients not achieving the optimal therapeutic target. Direct oral anticoagulants (DOAC) have replaced VKA therapy in the past for several indications, e.g., atrial fibrillation. However, it is still unclear if DOACs could replace VKA therapy in patients after mechanical aortic valve replacement. While the PROACT-Xa study did not show a sufficient anticoagulatory effect of apixaban plus aspirin compared to VKA therapy in patients after mechanical aortic valve replacement, the direct thrombin inhibitor dabigatran and the oral factor Xa inhibitors apixaban and rivaroxaban showed promising results in comparable patient cohorts in smaller studies and case reports. Factor Xa inhibitors were able to prevent thrombosis and thrombo-embolic events in patients after mechanical aortic valve replacement. Therefore, factor Xa inhibitors or factor XI inhibitors could provide a potent alternative to VKA for patients after a mechanical aortic valve replacement.

A prospective observational study to evaluate a possible relationship between vitamin K antagonist therapy and risk of peripheral arterial disease in patients with type 2 diabetes.

The use of vitamin K antagonists (VKAs) may increase the risk of peripheral arterial disease (PAD) because vitamin K is a strong inhibitor of medial arterial calcification. Type 2 diabetes (T2D) exposes patients to an increased risk of PAD. We examined how the use of VKAs modulates the risk of incident PAD in people with T2D. SURDIAGENE is a French cohort including 1468 patients with T2D with a prospective follow-up from 2002 to 2015. The primary outcome of the current analysis was the first occurrence of PAD, a composite of lower-limb amputation (LLA) or lower-limb revascularization. LLA and lower-limb revascularization were considered individually as secondary outcomes. During a 7-year median follow-up, PAD occurred in 147 (10%) of the 1468 participants. The use of VKAs was not significantly associated with the risk of PAD [multivariable adjusted hazard ratio (HR) 1.42, 95% confidence interval (CI), 0.88-2.31]. During the study period, LLA and lower-limb revascularization occurred in 82 (6%) and 105 (7%) participants, respectively. The use of VKAs was significantly associated with increased risk of LLA [multivariable adjusted HR 1.90 (95% CI, 1.04-3.47)], but not lower-limb revascularization [multivariable adjusted HR 1.08 (95% CI, 0.59-1.97)]. In this prospective study, we did not observe any excess risk of PAD requiring lower-limb revascularization in people with type 2 diabetes using VKAs. However, our data suggest a high risk of LLA in VKA users. Further studies are required to confirm this observation.

Anticoagulants - The Past, The Present, The Future - A Systematic Review

Introduction: Anticoagulants have been discovered and developed over past 100 years. At the beginning unfractionated heparin found its applications, just later to fade into the background of newer and more effective drugs. Patients have been treated with more progressive medications – Low-Molecule-Weight Heparin (LMWH), Vitamin K Antagonists (VKA) and Novel Oral Anticoagulants (NOAC). As for today, deemed a turning point in anticoagulant therapy are inhibitors of factor XI. It is a ground-breaking innovation as it ensures high prevention of thrombotic episodes and guarantees intact physiological hemostasis.Current State of Knowledge: The coagulation cascade and molecules part taking in that have been discovered and described extensively and in detail. Unfractionated heparin is the oldest out of all and despite its simple action mechanism and adverse effects, is still a requested drug. Its lighter form, low-molecule-weight-heparin (LMWH) is an enhancement to the previous treatment due to its higher bioavailability and fewer side effects. Vitamin K antagonists (VKAs) are widely spread in medical environment thanks to their expanded mechanism of action, oral administration and reversibility of their overdose, as well as their well-developed anti-side effect therapy. Novel Oral Anticoagulants (NOACs) have been introduced to the market about 10 years ago. In spite of NOACs short period of clinical use, they were a huge change to the previous treating methods. Currently, the newest innovation in anticoagulant therapy are inhibitors of factor XI and its clinical trials outcome is promising for the future.Summary: The present article discusses history of anticoagulant drugs, their mechanism of action and usage but also focuses on the recent perspectives and developments as new anticoagulant drugs are being put to the test in therapeutic trials. The review underlines the importance of improvements in old therapeutic methods and exploring the new, more suitable ones.

Omission of Antiplatelet Therapy in Patients With HeartMate 3 Left Ventricular Assist Devices: A Systematic Review and Meta-Analysis.

The HeartMate 3 (HM3) left ventricular assist device has decreased thromboembolic events and minimized the risk of pump thrombosis. However, bleeding complications due to combined antithrombotic therapy with a vitamin K antagonist (VKA) and aspirin remain high. Only limited data on the safety of VKA monotherapy in HM3 patients are available. A systematic search on the main databases was performed. Observational data and randomized trials were eligible for this analysis. As primary endpoint, we analyzed hemocompatibility-related adverse events (HRAE). As secondary endpoints, we investigated the individual components of the primary endpoint. The analysis was carried out using the odds ratio (OR) as outcome measure. A random-effects model was fitted to the data. Five manuscripts fulfilled the inclusion criteria. These trials included 785 patients (381 on VKA monotherapy, 404 on VKA and aspirin). VKA monotherapy significantly reduced HRAE (OR: 0.11 [95% confidence interval {CI}: 0.02-0.59], p = 0.01, I2 = 87%). The reduction was driven by a decrease in bleeding complications (OR: 0.12 [95% CI: 0.02-0.62], p = 0.01, I2 = 86%) without increasing the rates of thromboembolic events (OR: 0.69 [95% CI: 0.26-1.81], p = 0.45, I = 0%). Vitamin K antagonist monotherapy is associated with a significant reduction of bleeding events without increasing the risk of thromboembolic complications in HM3 patients.

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

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. 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. 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. 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.

Mechanical Thrombectomy in Anticoagulated Patients With Acute Ischemic Stroke: A Meta-Analysis.

According to a previous studies, mechanical thrombectomy(MT) is safe for anticoagulated patients. However, the safety and prognosis of direct oral anticoagulants (DOACs) and vitamin K antagonists (VKA) have not been compared with those of MT.This meta-analysis aimed at determining the efficacy of DOACs or VKA for patients after MT. We searched PubMed, Embase, Web of Science databases, and Cochrane from their inception to Aug 2022. Revman 5.3 served for the meta-analysis. The meta-analysis included 12 studies that covered 3571 patients, finding that after MT treatment, DOACs significantly decreased the symptomatic intracerebral hemorrhage [odd ratio (OR)=0.49, 95% CI 0.30-0.80, P =0.004] and mortality (OR=0.63, 95% CI 0.48-0.83, P =0.001) compared with VKA. Meanwhile, no obvious differences were found between DOACs and VKA after MT treatment in terms of in any hemorrhagic transformation (OR=1.07, 95% CI 0.84-1.37, P =0.59), good functional outcome (OR=1.06, 95% CI 0.88-1.27, P =0.53), and successful arterial recanalization (OR=1.24, 95% CI 1.00-1.53, P =0.05). This meta-analysis demonstrates that the application of DOACs in MT treatment for anticoagulated patients with acute ischemic stroke is safer than that in the VKA group. However, further studies are necessary to confirm these results.

Oral anticoagulants and cognitive impairment in patients with atrial fibrillation: A systematic review with meta-analysis and trial sequential analysis

BackgroundThis systematic review assesses the likelihood of developing dementia and cognitive impairment in patients with atrial fibrillation (AF) receiving non-vitamin K antagonist oral anticoagulants (NOACs) as opposed to vitamin K antagonists (VKAs). MethodsWe performed a systematic review with meta-analysis and trial sequential analysis (TSA), which encompassed both randomized controlled trials (RCTs) and observational studies. The objective was to assess the impact of NOACs and VKAs on the incidence of dementia in individuals diagnosed with AF. ResultsOut of 1914 studies that were screened, 31 studies were included in the final analysis, which consisted of nine RCTs or their subsequent post-hoc analyses, in addition to 22 observational studies. The meta-analysis shows that NOACs were associated with a decreased probability of developing dementia of any cause [Rate Ratio (RR): 0.88; 95 % confidence interval (95 % CI): 0.82–0.94], especially in patients below the age of 75 (RR: 0.78; 95 % CI: 0.73–0.84). Consistent patterns were observed across all forms of dementia and cognitive function decline. The overall evidence indicates notable variability in the outcome with a moderate-to-low degree of certainty. The TSA suggests that the total sample size of the included trials (155,647 patients) was significantly smaller than the required information size of 784,692 patients to discern the true effect of NOAC versus VKA in terms of reducing dementia risk. ConclusionNOACs may reduce the likelihood of developing dementia in patients with AF, particularly in those under the age of 75. This review highlights the urgent necessity for thorough research to determine the efficacy of NOACs in safeguarding cognitive health.

Effectiveness of Novel Oral Anticoagulants Versus Warfarin in Patients With Atrial Fibrillation: A Systematic Review and Meta-Analysis.

Atrial fibrillation (AF) is a common cardiac arrhythmia associated with an increased risk of stroke and systemic embolism (SE). Anticoagulation therapy, particularly with vitamin K antagonists (VKA) or novel oral anticoagulants (NOACs), is essential for stroke prevention in patients with AF. However, the comparative effectiveness of NOACs and warfarin remains debatable. Of the 34 studies included, 14 studies involving 166,845 patients were included in the meta-analysis and 20 studies were included in the systematic review. Our findings indicate that NOACs were associated with a significantly lesser risk of stroke/SE with a relative risk (RR) of 0.84 and p=0.0005, and all-cause mortality RR=0.88 and p=0.006. There were no significant differences between major bleeding events with an RR of 0.87 and p=0.22, and serious adverse events (SAE) with RR=1.01 and p=0.35, compared to warfarin in patients with AF. Our meta-analysis demonstrates strong evidence for the superiority in reducing stroke/SE and all-cause mortality of NOACs compared to warfarin. However, no significant differences were identified in the bleeding outcomes or SAEs between the two groups.