Vitamin K Antagonists Research Articles

Bleeding Risk of Anticoagulation Reversal Strategies Before Heart Transplantation: A Retrospective Comparative Cohort Study

Heart transplantation (HT) poses high bleeding risks, especially for patients on anticoagulation. This study evaluates the use of idarucizumab for dabigatran (DBG) reversal compared to vitamin K antagonist (VKA) strategies in HT. A retrospective analysis of HT patients from January 2018 to December 2022, excluding those requiring ECMO immediately before or after surgery, was conducted. Outcomes included transfusion needs, re-surgery due to bleeding, ICU stay lengths, and 30-day survival. A cost analysis compared the direct expenses of each strategy. Among 34 patients, 20 were on DBG and 14 on VKAs or not anticoagulated. Idarucizumab significantly reduced the number of patients requiring transfusion (p = 0.034) and ICU stay lengths (p = 0.014), with no significant impact on re-surgery rates (p = 0.259) or survival (p = 0.955). Despite higher initial costs, overall expenses for idarucizumab were comparable to VKA reversal due to reduced transfusion needs and shorter ICU stays. Idarucizumab offers a viable and potentially cost-neutral anticoagulation reversal option for HT patients on DBG, presenting an alternative to VKA strategies. However, due to the retrospective nature of the study and the small sample size, further prospective studies are needed to confirm these findings.

Abstract 4138813: The Use of Direct Oral Anticoagulants for Valvular Atrial Fibrillation in Central Australia

Background: In developed countries, valvular atrial fibrillation (vAF) in the setting of rheumatic heart disease (RHD) disproportionately impacts minority groups. In Australia, Indigenous Australians account for 92% of cases despite only representing 3.8% of the population. Studies to date, such as the INVICTUS trial, support the use of Vitamin K antagonists (VKAs) over direct oral anticoagulants (DOACs) in vAF. However, this assumes consistent adherence and regular clinic follow up. Reduced access to monitoring and dispensing clinics in Central Australia remains a challenge in the provision of VKAs and the use of DOACs may address this. Hypothesis: DOACs may be comparably effective with VKAs in preventing major adverse cardiac and cerebrovascular events (MACCE) in a real-world vAF population. Aim: To conduct a real-world retrospective observational study examining rates of MACCE for patients on VKAs or DOACs for vAF in Central Australia over a five-year period. Methods: The Northern Territory RHD Register was accessed to identify patients with RHD and vAF in January 2019. Demographic and five-year outcome data (until January 2024) were collected. The primary outcome was MACCE, a composite of ischaemic stroke, systemic embolism, non-fatal myocardial infarction, cardiovascular death and all-cause mortality. The primary safety endpoint was major bleeding. Statistical analyses were conducted as both intention-to-treat (ITT) based on initial anticoagulation and as-treated (AT) based on anticoagulation prior to MACCE or trial endpoint, each excluding patients without anticoagulation. Results: 61 patients were included. The mean age was 61.9 ± 13.9 years and 68.9% were female. At baseline, 65.6% received VKA, 14.8% DOAC and 19.7% were not anticoagulated. 30.6% of patients crossed over from the ITT analysis, with a non-significant trend favouring switch to DOAC (11 vs 0, p=0.09). In the ITT analysis (n=49), there was no significant difference in MACCE (25.0% vs 22.2%, p=0.86) or major bleeding (20.0% vs 11.1%, p=0.53) between VKA and DOAC groups. In the AT analysis (n=51), there was no significant difference in MACCE (27.3% vs 16.7%, p=0.39) or major bleeding (18.2% vs 22.2%, p=0.73) between VKA and DOAC groups. Conclusion: Over a five-year period, there was a trend towards use of DOACs over VKAs in vAF. This study demonstrates that DOACs may be as effective as VKAs for reducing MACCE in a real-world vAF population however further investigation is required.

Systematic vitamin K antagonist reversal with prothrombin complex concentrate in patients with mild traumatic brain injury: randomized controlled trial.

Traumatic brain injury (TBI) in patients on vitamin K antagonists (VKAs) is linked to a high rate of intracranial hemorrhage (ICH). Rapid reversal can reduce ICH progression and mortality, but its effectiveness depends on the time between bleeding onset and coagulation normalization. The PREVACT study aimed to assess the efficacy and safety of prompt systematic reversal of anticoagulation in patients presenting to emergency departments (EDs) for recent mild-TBI while receiving a VKA. A randomized, open-label, blinded-endpoint clinical trial was conducted in 21 French EDs. Patients receiving a VKA, having experienced a TBI within the last 6 h, and presenting a Glasgow Coma Score ≥13 were included. Patients were randomized to systematic immediate VKA reversal with 25 IU/kg of four-factor prothrombin complex concentrate (4f-PCC) before any investigation (intervention group) or standard-of-care signifying reversal only if the initial cranial computed tomography (CT) scan indicated ICH (control group). The primary outcome was the rate of ICH detected on a cranial CT scan 24 h post-inclusion. The study was prematurely stopped for logistic reasons after the randomization of 202 patients (101 and 101 in the intervention and control groups, respectively, mean age 90; 51.8% female). On the 24-h cranial CT scan, 6 of 98 patients (6.1%) in the intervention group manifested ICH vs. 12 of 99 patients (12.1%) in the control group [odds ratio: 0.47 (95% confidence interval: 0.14-1.44); P = 0.215]. In patients with recent mild-TBI receiving a VKA, systematic prompt reversal with 4f-PCC did not statistically significantly reduce ICH rate at 24 h. However, the study was prematurely stopped and does not exclude a clinically relevant benefit of the strategy tested. Clinicaltrials.gov (NCT01961804).

International Normalized Ratio measurement during perioperative anticoagulation bridging with Low Molecular Weight Heparin in patients undergoing heart valve replacement surgery

BackgroundSurgical procedures in anticoagulated patients require specific attention due to increased bleeding risk. Preoperative anticoagulation interruption in high-risk patients is often necessary. Bridging anticoagulation with low-molecular-weight heparin (LMWH) minimizes thromboembolic risk, but its effect on INR measurement is not well established, necessitating careful monitoring and individual assessment. ObjectivesInvestigating the effect of heparin bridging on INR measurements in anticoagulated patients on vitamin K antagonist (VKA) and by in vitro spiking experiments. Methods38 anticoagulated patients on VKA undergoing valve replacement surgery were studied using two plasma-based INR assays and one whole blood point-of-care INR method on multiple timepoints after postoperatively resuming VKA. Furthermore, we compared INR levels in pooled plasma of both normal and VKA-treated individuals, with seven spiked concentrations of LMWH or unfractionated heparin (UFH) in four INR assays. ResultsIn LMWH-bridged anticoagulated patients, the INR results obtained with HemosIL® RecombiPlasTin® and point-of-care Coaguchek are significantly higher compared to STA® Hepato Prest, within 3 days after restart of VKA. After spiking of LMWH or UFH in various concentrations into pooled plasma, only STA® Hepato Prest assay shows no interference in INR measurement within the therapeutic range (1.0-2.0 international units/mL) in both VKA and normal plasma. All other assays have substantial interference, with the Thromborel® S assay being the most heparin-sensitive assay. ConclusionDifferences between INR methods are seen within 72 hours after restarting VKA in post-operative patients who receive LMWH-bridging. In vitro experiments using LMWH and UFH show the interference of heparin in multiple INR methods, even with concentrations below suppliers-stated heparin interference limits.

Efficacy and Safety of Direct Oral Anticoagulants Compared to Warfarin in Patients with Cirrhosis and Splanchnic Vein Thrombosis.

The incidence of splanchnic vein thrombosis (SVT) is reported to be <25 times lower than that of deep vein thrombosis and pulmonary emboli, which occur in 70 to 270/100,000 cases in the general population. Current guidelines recommend initial treatment with therapeutic low-molecular-weight heparin followed by a transition to a vitamin K antagonist (VKA) or a direct oral anticoagulant (DOAC) in patients with cirrhosis who develop SVT without severe liver dysfunction. This, however, is based on observational data. This study aimed to evaluate the efficacy and safety of anticoagulant therapy in patients with cirrhosis who present with SVT and receive either a DOAC or a VKA. This multicenter retrospective cohort study was conducted from December 2021 to November 2022. Patients between the ages of 18 and 75 years with cirrhosis and acute SVT who received either a VKA or a DOAC between July 2019 and July 2021 were eligible for inclusion. The primary outcome was the efficacy of treatment, defined as a new thrombotic event. The secondary outcome was the safety of treatment, defined as the development of major bleeding. Readmission data were followed up at 6 and 10 months. Bivariate analysis was conducted to assess the relationship between the medication groups and each outcome and summarized as odds ratios (ORs) with 95% confidence intervals (CIs). Statistical significance was set at 5% for all of the comparisons. A total of 80 patients from 50 hospitals were included in this study. Sixty-one patients (59.02% male) received DOACs and 19 (57.89% male) received a VKA. Of the patients who received DOACs, 41 (67.21%) received apixaban, one (1.64%) received dabigatran, and 19 (31.15%) received rivaroxaban. The results from the bivariate analysis revealed no significant differences between DOACs and warfarin for both the efficacy (OR 1.46, 95% CI 0.44-4.84, P = 0.53) and safety outcomes (OR 1.03, 95% CI 0.04-26.43, P = 1) at 10 months. The use of DOACs in patients with cirrhosis who present with SVT may be efficacious and safe compared with warfarin. The findings from our study may inform power analyses for well-conducted randomized trials to confirm these findings.

Clinical Features, Management, and Recurrence of Acute Ischemic Stroke Occurring in Patients on Oral Anticoagulant Treatment for Nonvalvular Atrial Fibrillation: A Real-World Retrospective Study.

The optimal management of acute ischemic stroke (AIS) in patients with oral anticoagulation (OA) is challenging. Our study aimed to analyze the clinical characteristics and outcome of AIS in patients with OA for nonvalvular atrial fibrillation (NVAF). We retrospectively analyzed data on NVAF patients with AIS on direct oral anticoagulants (DOAC) or vitamin K antagonists (VKA) admitted to our Stroke Unit from 2017 to 2022. Ninety-day modified Rankin Scale (mRS), 90-day, and 12-month stroke recurrences were recorded. A total of 169 patients (53.2% female, mean age 82.8±6.7 y), 117 (69.2%) on DOAC, and 52 on VKA (30.8%), were enrolled. Mean age, in-hospital mortality, and 90-day mRS ≥4 were significantly higher in VKA patients. 63.4% of VKA patients had subtherapeutic INR, whereas 47.1% of DOAC patients were on low-dose (14.2% off-label). Large vessel occlusion and embolic etiology were more frequent in VKA patients (34.6% vs. 26.4%, P =0.358; 92.3% vs. 74.3%, P =0.007, respectively), whereas lacunar strokes were more frequent in DOAC patients (19.8% vs. 12.2%, P =0.366). Among patients on VKA before AIS 86.4% were switched to DOAC, whereas a DOAC-to-VKA and a DOAC-to-DOAC switch were done in 25.4% and 11.7%, respectively. Stroke recurrence occurred in 6.4% of patients at 90 days and 10.7% at 12 months. Anticoagulant switching was not associated with stroke recurrences. In our study, nonembolic etiology was more frequent in DOAC patients and anticoagulant switching did not reduce the risk of stroke recurrence. Prospective multicentric studies are warranted.

From the INVICTUS Trial to Current Considerations: It’s Not Time to Retire Vitamin K Inhibitors Yet!

Atrial fibrillation (AF) is a common arrhythmia in clinical practice, and oral anticoagulation is the cornerstone of stroke prevention in AF. Direct oral anticoagulants (DOAC) significantly reduce the incidence of intracerebral hemorrhage with preserved efficacy for preventing stroke compared to vitamin K antagonists (VKA). However, the pivotal randomized controlled trials (RCTs) of DOAC excluded patients with valvular heart disease, especially mitral stenosis, which remains an exclusion criterion for DOAC use. The INVICTUS study was a large multicenter global RCT aimed at evaluating the role of DOAC compared to VKA in stroke prevention among patients with rheumatic valvular AF. In this study, rivaroxaban failed to prove superiority over VKA in preventing the composite primary efficacy endpoints of stroke, systemic embolism, myocardial infarction, and death. Unfortunately, the bleeding rates were not lower with rivaroxaban either. The death and drug discontinuation rates were higher in the DOAC arm. Close to the heels of the dismal results of INVICTUS, an apixaban trial in prosthetic heart valves, PROACT-Xa, was also prematurely terminated due to futility. Hence, for AF complicating moderate-to-severe mitral stenosis or prosthetic valve VKA remains the standard of care. However, DOAC can be used in patients with surgical bioprosthetic valve implantation, TAVR, and other native valve diseases with AF, except for moderate-to-severe mitral stenosis. Factor XI inhibitors represent a breakthrough in anticoagulation as they aim to dissociate thrombosis from hemostasis, thereby indicating a potential to cut down bleeding further. Multiple agents (monoclonal antibodies—e.g., osocimab, anti-sense oligonucleotides—e.g., fesomersen, and small molecule inhibitors—e.g., milvexian) have garnered positive data from phase II studies, and many have entered the phase III studies in AF/Venous thromboembolism. Future studies on conventional DOAC and new-generation DOAC will shed further light on whether DOAC can dethrone VKA in valvular heart disease.

The effect of Vitamin K antagonists as anticoagulants on bleeding in patients post-dental procedures

Background: Individuals undergoing continuous treatment and taking vitamin K antagonist (VKA) and other anticoagulant medications are at a higher risk of experiencing bleeding complications during and after dental surgery procedures. Objective: To determine the effect of vitamin K antagonists in post-dental procedure patients by exploring existing literature on managing patients on vitamin K antagonist therapy as anticoagulants. Methods: This research utilized a literature review based on a database search of studies published between 2019-2024. The literature search used strategies with the terms “Tooth extraction bleeding,” “Odontectomy bleeding,” “Vitamin K Antagonist,” and “Anticoagulant,” utilizing databases such as PubMed, Science Direct, and SCOPUS related to the research topic and meeting eligibility criteria. The studies were then reviewed, summarized, and conclusions were drawn using tables to reveal all data regarding study characteristics and results. Results: Patients using anticoagulants are categorized as high risk for bleeding when undergoing invasive dentistry procedures. VKA is the most commonly used anticoagulant to prevent blood clotting. The consumption of VKA does not significantly affect bleeding post-procedure. Dental procedures can be performed on patients taking anticoagulants without discontinuing the therapy. Conclusion: Based on several studies from various literature sources, it can be concluded that dental procedures in patients taking vitamin K antagonist anticoagulants can still be performed without the risk of bleeding complications with proper local hemostatic measures and perioperative management.

Consequences of the Poor Anticoagulation Control of Patients with Non-Valvular Atrial Fibrillation Treated with Vitamin K Antagonists

Background: The prevention of thromboembolisms through anticoagulation and heart rate control is crucial in managing non-valvular atrial fibrillation (NVAF). This study aimed to analyze the consequences of poor anticoagulation control with vitamin K antagonists (VKAs) in Spanish patients with NVAF, focusing on thrombotic events, bleeding, mortality, healthcare resources (HRU), and costs. Methods: This observational, retrospective study used electronic medical records (BIG-PAC® database) of NVAF patients who started VKA treatment between 1 January 2016 and 31 December 2018. Patients were followed up for two years and classified by poor or adequate anticoagulation control. Demographic and clinical characteristics, treatments, incidence of cardiovascular events, mortality rates, HRU, and costs were analyzed. Results: Patients with poor control (n = 2136) had a 75% greater probability of suffering a cardiovascular event compared to patients with adequate control (n = 2351) (HR, 1.75 [95%CI: 1.43–2.14; p &lt; 0.001]). Cardiovascular events, major bleeding, minor bleeding, systemic thromboembolism, and ischemic strokes were reduced by 32.1%, 46.2%, 29.6%, 22.2%, and 16.1%, respectively. It was estimated that adequate anticoagulant control saved EUR 455/patient with NAVF due to reduced hospitalization for cardiovascular events. Conclusions: For VKA-treated NVAF patients, poor anticoagulation control was associated with a higher number of cardiovascular events, greater consumption of HRU, and higher management costs than for patients with adequate control.

Long-term Impacts of Long COVID: Increased Incidence of Cardiomyopathies, Joint Diseases, and Psychoanxiety Disorders.

The COVID-19 pandemic has intensified inquiries into the interplay between diabetes and disease severity, and the long-term impact of long-COVID. This study specifically explored the implications of different antithrombotic treatments on COVID-19 patients. It aimed to assess the long-term efficacy and safety of Vitamin K antagonists (VKA) and direct oral anticoagulants (DOACs) in mitigating thromboembolic complications in COVID-19 patients. We conducted a study on 157 patients diagnosed with COVID-19 from August 2021 to August 2023. The study evaluated shifts in anticoagulant therapy recommendations, tracking the transition from VKA to DOACs, and analyzed associated health outcomes. A significant shift from VKA to DOACs prescriptions was observed, especially in high-risk patients. Despite the change in antithrombotic treatments, incidences of varices and varices with hemorrhoids increased by 2.6% and 3.2%, respectively. Long-COVID was also linked to higher occurrences of diabetes and gastrointestinal diseases. Joint diseases rose by 14%, indicating persistent inflammation. Cardiomyopathies increased by 3.9%, predominantly in high-risk groups, and psychoanxiety disorders surged by 39.5%, highlighting the need for further research. DOAC usage was more common in older age groups, with a 10.2% increase in recommendations among high-risk patients (p<0.05). The study underscores the evolving landscape of antithrombotic therapy in managing COVID-19 complications. Despite the increased use of DOACs, the rise in various health conditions suggests the necessity for personalized treatment strategies tailored to patient risk profiles.

Impact of resumption of Oral AntiCoagulation therapy (OAC) after GastroIntestinal Bleeding (GIB) on clinical outcomes in patients with Non-Valvular Atrial Fibrillation (NVAF)

Abstract Purpose Optimal resumption of oral anticoagulation therapy (OAC) after gastrointestinal bleeding (GIB)has not been well established. This study aimed to compare clinical outcomes between patients who resumed or discontinued OAC after index GIB. Methods We retrospectively enrolled consecutive patients with non-valvular atrial fibrillation (NVAF) and prior GIB from January 2018 to July 2022 in 16 public hospitals in Hong Kong. Resumption of OAC was substantiated by new prescription after index GIB on electronic medical records. Patients were divided into 5 groups: (i) OAC naïve (as reference group); (ii) resume direct oral anticoagulant (DOAC); (iii) resume Vitamin K antagonist (VKA); (iv) discontinue DOAC; (v) discontinue VKA. Endpoints included recurrent GIB, ischemic stroke and all-cause death. Risks of target events were estimated for all groups and compared with individuals without OAC, using adjusted sub-distribution hazard ratios (aSHR) derived from Fine and Gray regression models, accounting for death as competing risk for recurrent GIB and stroke, and COX proportional regression for all-cause mortality, adjusting for components of CHA2DS2VASC, HASBLED scores, causes of index GIB (i.e., GI ulcer, diverticular disease, angiodysplasia or undermined) and endoscopy intervention. Among patients who resumed OAC, outcomes were compared between different DOAC agents (i.e, apixaban, dabigatran, edoxaban, rivaroxaban), using VKA as reference. Results Of 2,350 patients identified (mean age 80.5±10.4, female 54.5%), 44.0% (n=1,034) were OAC naïve, 4.4% (n=103) discontinued VKA, 11.7% (n=275) discontinued DOAC, 11.2% (n=263) resumed VKA, and 28.7% (n=675) resumed DOAC. During a median follow-up duration of 1.2(IQR:0.2-2.5) years, discontinuation of DOAC (aSHR=0.5(0.29-0.9) was associated with lower risk of recurrent GIB, whereas resumption of VKA (aSHR=1.8(1.0-3.1)) was associated with the highest risk of recurrent GIB (Figure 1a). Among DOACs, apixaban (aSHR=0.5(0.3-0.9)) was associated with the lowest risk of recurrent GIB (Figure 1b). Risk of ischemic stroke across groups were similar. Patients who discontinued DOAC (aHR=1.4(1.2-1.6)) were at higher risk of all-cause mortality, whereas resumption of VKA (aHR=0.4(0.3-0.6)) and DOAC (aHR=0.4(0.4-0.5)) were both associated with decreased mortality (Figure 1c). Conclusion In this real-world dataset, resumption of VKA in NVAF patients after GIB was associated with high risk of recurrent GIB and lowest risk with apixaban. OAC resumption either VKA or DOAC was associated with reduced mortality.

Resumption of anticoagulation therapy among Non-Valvular Atrial Fibrillation (NVAF) patients with prior intracranial haemorrhage

Abstract Purpose Resumption of anticoagulation therapy (OAC) in patients with non-valvular atrial fibrillation (NVAF) suffering from intracranial haemorrhage (ICH) is challenging in clinical practice. The aim of this study was to evaluate impact of resumption of OAC on clinical outcomes in NVAF patients with history of ICH. Methods Consecutive patients with NVAF with or without OAC who survived from an index ICH between January 2018 and July 2022 in 16 public hospitals in Hong Kong were identified and analyzed retrospectively. Resumption of OAC was substantiated by new prescription obtained from electronic medical records. Patients were divided into 5 groups: (i) OAC naïve (as reference group); (ii) resume direct oral anticoagulant (DOAC); (iii) resume Vitamin K antagonist (VKA); (iv) discontinue DOAC; (v) discontinue VKA. Risks of ischemic stroke, recurrent ICH and all-cause mortality were estimated for all groups and compared with individuals without OAC, using adjusted sub-distribution hazard ratios (aSHR) derived from Fine and Gray regression models, accounting for death as competing risk, adjusting for components of CHA2DS2VASC and HASBLED scores. Sub-analysis was conducted to compare outcomes between different DOAC agents (i.e, apixaban, dabigatran, edoxaban, rivaroxaban), using VKA as reference among patients who resumed DOAC or VKA. Results Of 982 patients who met inclusion criteria (mean age 77.7±10.9, female 40.9%), 39.1% (n=384) were OAC naive, 32.2% (n=316) resumed DOAC, 12.6% (n=124) resumed VKA, 9.0% (n=88) discontinued DOAC and 7.1% (n=70) discontinued VKA. During a median follow-up period of 2.0 (IQR: 0.7-3.5) years, no statistically significant difference in risk of ischemic stroke was observed among 5 groups. Discontinuation of DOAC was associated with markedly higher risk of ischemic stroke (aSHR=8.32 (1.8-39.3)) only among AF patients with CHA2DS2VASC score ≥ 4, Risk of recurrent ICH was higher in patients who resumed VKA (aSHR=1.6(1.0-2.5)). Sub-analysis demonstrated resumption of apixaban was associated with lowest risk of recurrent ICH (aSHR=0.6(0.4-0.9)). Compared to OAC naïve patients, those who resumed DOAC (aSHR=0.5(0.4-0.7)) had lowest risk of all-cause mortality, whereas discontinuation DOAC (aSHR=1.9(0.4-2.5) and VKA (aSHR=1.6(0.2-2.2)) were both associated with increased mortality. Conclusion Our real-world data revealed among NVAF patients with prior ICH long term discontinuation of OAC was associated with increased risk of ischemic stroke. Recurrent ICH was highest among patients who resumed VKA and lowest with apixaban.

Direct oral anticoagulants exhibit lower risks of mortality and bleeding compared to vitamin-k antagonists in atrial fibrillation patients on chronic hemodialysis: a meta-analysis

Abstract Background Atrial fibrillation (AF) is a common arrhythmia in patients with chronic kidney disease (CKD). Although direct oral anticoagulants (DOACs) are equally or more effective than vitamin K antagonists (VKAs) in patients with moderate CKD, evidence claiming the benefits of DOACs over VKAs in patients on hemodialysis (HD) is scarce. Purpose This meta-analysis aimed to assess the outcomes of patients with AF on chronic HD by comparing the clinical outcomes of DOACs versus VKAs. Methods A systematic literature search was conducted across various databases to retrieve studies focusing on efficacy and safety outcomes in patients with AF on chronic hemodialysis comparing DOACs and VKAs. Relative risks (RRs) with 95% confidence intervals (CIs) were pooled using the Mantel-Haenszel random-effects model in Review Manager 5.4. Statistical significance was set at p &amp;lt;0.05. Results Nine studies with 39, 831 patients were included. The risk of all-cause mortality [RR: 0.73; 95% CI: 0.60, 0.88; p=0.001], major bleeding [RR: 0.63; 95% CI: 0.52, 0.76; p&amp;lt;0.00001], gastrointestinal bleeding [RR: 0.67; 95% CI: 0.53, 0.85; p=0.0009], intracranial hemorrhage [RR: 0.57; 95% CI: 0.38, 0.84; p=0.004], all-cause stroke [RR: 0.64; 95% CI: 0.51, 0.81; p=0.0001], and ischemic stroke [RR: 0.53; 95% CI: 0.29, 0.96; p=0.04] were lower in the DOAC group than in the VKA group. The risk of cardiovascular-related death [RR: 1.34; 95% CI: 0.69, 2.60; p=0.39], and clinically relevant non-major bleeding [RR: 0.90; 95% CI: 0.75, 1.08; p=0.26] showed no significant differences. Conclusion The risks of all-cause stroke, ischemic stroke, all-cause mortality, major bleeding, gastrointestinal bleeding, and intracranial hemorrhage in the patients with AF undergoing chronic HD were lower in the DOAC group than in the VKA group. Further large-scale RCTs are needed to generate more robust evidence through adequately powered studies, leading to conclusive results that are applicable to real-world scenarios.

Implications of renal function on adverse clinical events in patients with atrial fibrillation: a comparative analysis of VKA and NOAC therapy - Insights from the GLORIA-AF Registry Phase III

Abstract Background Renal function, as assessed by creatinine clearance (CrCl), plays a crucial role in determining the efficacy and safety of oral anticoagulant (OAC) therapy in patients with atrial fibrillation (AF). Purpose To investigate the relationships between CrCl and the risk of clinical adverse events in patients with AF receiving OAC therapy, comparing the safety profiles of vitamin K antagonists (VKA) and non-vitamin K antagonist oral anticoagulants (NOACs). Methods Anticoagulated AF patients from the prospective Global Registry on Long-Term Oral Anti-Thrombotic Treatment in Patients with Atrial Fibrillation (GLORIA-AF) registry Phase III were studied. CrCl was calculated for renal function, according to Cockcroft-Gault equation. Restricted cubic spline (RCS) were used to explore the nonlinear association between adverse end events and CrCl, comparing VKA and NOAC therapy. Cox regression models were used to analysis the associations between adverse end events and OAC therapy in patients with different CrCl levels, adjusted by clinical features and previous disease. Patients were followed up for the composite outcome (all-cause death, thromboembolism and major bleeding), all-cause death, cardiovascular disease (CVD), major bleeding, myocardial infarction (MI) and stroke. Results In 10,594 AF patients (mean age 70.35 ± 9.92 years; 55% male; 73% on NOAC), RCS analysis revealed decreased risks of all cause death, composite outcomes and CVD with increasing CrCl in patients with CrCl &amp;lt; 80 mL/min. Multivariate Cox models indicated that NOAC therapy associated with lower risk of all cause death (HR 0.68, 95% CI 0.58-0.78), composite outcomes (HR 0.77, 95% CI 0.68-0.86), CVD (HR 0.7, 95% CI 0.56-0.87), major bleeding (HR 0.74, 95% CI 0.61-0.91) in AF patients. For CrCl &amp;gt; 95 mL/min, a lower risk of all cause death (HR 0.56, 95% CI 0.38-0.82), composite outcomes (HR 0.68, 95% CI 0.51-0.91) and major bleeding (HR 0.54, 95% CI 0.35-0.85) were associated with NOAC therapy, vs. VKA. For CrCl &amp;lt; 30 mL/min, a lower risk of all cause death (HR 0.47, 95% CI 0.28-0.81), composite outcomes (HR 0.56, 95% CI 0.35-0.89) and CVD (HR 0.43, 95% CI 0.20-0.90) were related to NOAC therapy. No significant difference in outcomes between VKA and NOAC were found in patients with moderate CrCl. Conclusion Increasing CrCl were associated with decreased risk of adverse clinical events, including all-cause death and CVD in anticoagulated AF patients. For patients with CrCl &amp;gt;= 95 and &amp;lt; 30, NOAC therapy, was associated with lower risks of adverse outcomes.Figure 1Figure 2

Risk of thromboembolic and haemorrhagic events associated with anticoagulation among 11,355 patients with non-valvular atrial fibrillation and thrombocytopenia

Abstract Background Oral anticoagulation (OAC) is the mainstay for stroke prophylaxis in patients with non-valvular atrial fibrillation (NVAF). Management is challenging among patients with NVAF complicated with thrombocytopenia. Purpose We compared risk of thromboembolic and hemorrhagic events between vitamin-k antagonist (VKA) and direct oral anticoagulants (DOAC) users. Methods We retrospectively analyzed patients with thrombocytopenia and NVAF prescribed VKA (N=5,251, 46.2%) and DOAC (N=6,104, 53.8%) between January 2012 and July 2022 in 16 public hospitals in Hong Kong. Mild to moderate thrombocytopenia was defined as mean platelet count (PLT) 100-150 × 10^9/L and 50-100 × 10^9/L respectively, during the year of OAC initiation. Propensity-matched cohorts of VKA and DOAC were generated on the basis of age, sex, baseline co-morbidities (components of CHA2DS2VASC and HAS-BLED scores) and medications. Time to intracranial hemorrhage (ICH), gastrointestinal bleeding (GIB) and ischemic stroke (IS) was analyzed using competing risk regression, accounting for death as competing risk. Subgroup analysis was performed to detect heterogeneity of effect across mild and moderate thrombocytopenia. Secondary outcome included (i) comparisons between 4 DOAC agents with full dose; (ii) Full-dose DOAC vs. reduced-dose DOAC. Results Of the whole cohort (N=11,355, mean age 75.8±10.5, female 38.6%), 10.3% (n=1,174) and 89.7% (n=10,181) had moderate and mild thrombocytopenia, respectively. After propensity-score matching, VKA and DOAC (n=4,302 each cohort) users were well balanced at baseline characteristics, with a median follow-up of 4.0 (IQR: 1.6-7.3) years. Overall, utilization of DOAC was associated with reduced risk of ICH [Hazards Ratio (HR) 0.56 (95% CI 0.45-0.70)] and GIB [HR 0.60 (95% CI 0.48-0.75)], compared with VKA. No difference in risk of IS was observed [HR 1.00 (95%CI 0.83-1.20)]. Dosing reduction of DOAC made no difference in all outcomes. Subgroup analysis demonstrated the benefit in decreasing GIB might be more marked in moderate thrombocytopenia [(HR 0.24 (95%CI 0.09-0.61)], than in mild thrombocytopenia [HR 0.64 (95%CI 0.51-0.81)]. Conclusion In patients with NVAF and thrombocytopenia, DOAC has similar efficacy but better safety profile than VKA. In terms of GIB, the superiority appeared to be more pronounced in patients with more significant thrombocytopenia.

Comparative analysis of vitamin K antagonists and direct oral anticoagulants for left ventricular thrombus management: a retrospective study utilising TriNetX

Abstract Introduction Despite progress in cardiovascular medicine, guidelines for addressing left ventricular thrombus (LVT) remain limited. Furthermore, incorporating oral anticoagulants into dual antiplatelet therapy for acute myocardial infarction (MI) adds complexity to treatment decisions. While conventional guidance favors vitamin K antagonists (VKAs), emerging evidence suggests favorable outcomes with direct oral anticoagulants (DOACs). Purpose This study aims to assess the safety and efficacy of DOACs versus VKAs in managing LVT among patients with and without recent acute coronary syndrome (ACS). Methods This was a retrospective observational study conducted within TriNetX, a global federated health research network with access to electronic medical records (EMRs) from participating health care organizations including academic medical centres and community hospitals covering approximately 70 million individuals, mainly in the United States. The search was conducted on 26th Februrary 2024 with a study cohort comprising patients with LV thrombus treated with either DOAC or VKA between 1st December 2013 to 1st December 2023. Subgroup analyses were conducted for patients with ACS within one month and those without ACS within a month of treatment. Cohort data were subject to propensity matching (PSM) for age, gender, ethnicities, medical and drug history. Risk analysis and Kaplan-Meier survival analysis were computed for each subgroup at 90 days since the indexed event. Results Following PSM, a total of 39,770 patients were included and 14,302 were in the ACS group and 24,162 in the non-ACS group. DOAC treatment exhibited favourable outcomes for stroke, bleeding, and systemic embolism (p&amp;lt;0.05) compared to VKA in the overall cohort (Table 1). In the ACS group, DOAC was linked to a reduced risk of stroke and systemic embolism (p&amp;lt;0.05) but not bleeding (p=0.066). In the non-ACS group, DOAC was associated with a decreased risk of stroke and bleeding (p&amp;lt;0.05) but not systemic embolism (p=0.113). Across all groups, there were no disparities in overall all causes of mortalities. Conclusion DOACs demonstrated better safety and efficacy outcomes when compared to VKAs in LVT treatment. Interestingly, DOACs utilisation within the ACS context resulted in a diminished risk of embolic complications without the benefit of reduced bleeding risk seen in patients without ACS, suggesting potential implications of triple therapy within first month of ACS treatment, removing the bleeding risk reduction of DOACs. This shows a fundamental difference in LVT between the 2 groups of patients so future studies should aim to differentiate between the 2.

Direct Oral Anticoagulants versus Vitamin K Antagonists for the management of left ventricular thrombus after myocardial infarction: A meta-analysis

Abstract Background/Introduction Left ventricular (LV) thrombus formation is not an uncommon complication after acute myocardial infarction (AMI) in the modern era of early reperfusion. The optimal anticoagulation regimen in this clinical scenario remains poorly-defined. Purpose The present meta-analysis sought to investigate the efficacy and safety profile of direct oral anticoagulants (DOACs) compared with Vitamin K antagonists (VKAs) for the management of LV thrombus following AMI. Methods A systematic literature review was conducted in electronic databases to identify studies reporting efficacy and safety outcome data regarding the use of DOACs versus VKAs for patients with LV thrombus after MI. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated and random-effects meta-analyses were conducted to synthesize pooled ORs. Results Eight studies comprising a total of 605 patients were included (Table). DOACs were associated with an almost 2-fold higher likelihood for achieving thrombus resolution compared to VKAs (pooled OR 1.95 [1.25-3.04]; p =0.003, I2 =0 %), while they achieved a 70% lower risk for systemic embolism (pooled OR 0.30 [0.12-0.75]; p =0.01, I2 =0%). The use of DOACs was associated with a 54% lower risk for bleeding compared to VKAs (pooled OR 0.46 [0.26-0.84]; p =0.01, I2 =0 %). Overall, patients receiving DOACs had a 63% lower risk to reach the composite outcome of any bleeding, systemic embolism, cardiovascular hospitalization, or all-cause death, compared with patients using VKAs (pooled OR 0.37 [0.23-0.60]; p &amp;lt;0.0001, I2 =0%) (Figure). Conclusion DOACs appear to have a more favorable efficacy and safety profile compared to VKAs for the management of LV thrombus following AMI.Graphical abstractTable

Antithrombotic therapy and the risk of pocket hematoma after subcutaneous implantable cardioverter-defibrillator implantation

Abstract Introduction The PRAETORIAN trial, which randomized S-ICD versus TV-ICD in patients with a class I or IIa indication for ICD therapy, showed that clinically significant pocket hematomas were more frequent following S-ICD implantation. Many ICD recipients have comorbidities requiring anticoagulant (AC) and/or antiplatelet (AP) therapy, which increase the risk for hematoma formation post implantation. In contrast to TV-ICD implantation, little data exists regarding the optimal AC and AP strategy during S-ICD implantation to prevent pocket hematomas. Methods All patients who underwent de novo S-ICD implantations between February 2009 and January 2023 at our tertiary center were included. Data was collected retrospectively from electronic patient records. Clinically significant pocket hematomas were defined as an accumulation of blood at the pocket site within 30 days after S-ICD implantation, necessitating actions including applying a pressure bandage, surgical evacuation, drain insertion, a change in medication or an extended hospital stay or blood transfusion. Results A total of 348 patients were included of which 224 (64.4%) patients used antithrombotic therapy pre-implantation. Median age at implantation was 50 years (IQR: 36-61 years), 33.4% of the patients were female and the vast majority of implants were intermuscular (90.2%). Eighteen (5.2%) patients developed a clinically significant pocket hematoma. A total of 94 (27%) patients used AC therapy prior to the implantation of which 73 (21%) patients used a vitamin K antagonist (VKA). A total of 130 (37.4%) patients used AP therapy at baseline of which 49 (14.1%) patients were on dual AP therapy (DAPT). Continuation of VKA and continuation of DAPT with ticagrelor were independent predictors for pocket hematoma formation (p&amp;lt;0.001, and p&amp;lt;0.001 respectively). There were significantly more pocket hematomas in patients with continued VKA compared to patients with interrupted VKA (27.3 % (6/22) vs. 4.3% (2/47), respectively, p=0.011). Moreover, continuation of DAPT with ticagrelor was associated with significantly more pocket hematomas post implantation compared to continuation of DAPT with clopidogrel (4/12 vs 1/28, respectively, p=0.022). Conclusion This study showed that continuation of VKA during S-ICD implantation was associated with an increased risk of pocket hematoma formation compared to interruption of VKA. The continuation of DAPT with ticagrelor was an independent predictor of pocket hematoma formation and showed significantly more pocket hematomas compared to continuation of DAPT with clopidogrel. These findings support the need for specific peri-operative thrombotic therapy guidelines for S-ICD implantations to reduce the risk of pocket hematomas.

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&amp;lt; 0.01). The incidence was also significantly different in the DOAC and VKA cohorts (p&amp;lt;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 (&amp;gt;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.