Low Molecular Weight Heparin Research Articles

Development and attestation of a standard sample of calcium nadroparin

Introduction. The widespread use of heparin preparations for the treatment and prevention of venous thromboembolic complications is known. One of the low molecular weight heparin drugs successfully used in clinical practice is calcium nadroparin. The modern approach to assessing the quality of medicines involves the use of standards, in comparison with which the quality control of the drug is carried out – standard samples (SS). The most important specific parameter in assessing the authenticity of low molecular weight heparins is the characteristic of the fractional composition.Aim. The aim of the work was to develop, attestation and determine the stability during the shelf life of a secondary standard sample to determine the authenticity of calcium nadroparin as part of improving the quality control system of the enterprise with the prospect of creating a domestic pharmacopoeia standard sample.Materials and methods. The object of development and attestation was the standard sample of the enterprise – low molecular weight heparin, obtained on the basis of the Technology implementation center of Siberian state medical university. The certified standard sample was obtained by purification of calcium nadroparin by solid-phase extraction. The completeness of the purification was confirmed by comparing the chromatograms of the purified samples with the chromatograms of the international standard sample. The characteristics of the molecular weight distribution were determined chromatographically. The stability of the certified SSE (the standard sample of the enterprise) was studied under two storage conditions – at a temperature below 8 °C in a dry state for 16 months and in solution at –40 °C for 6 months by evaluating trends in molecular weight distribution.Results and discussion. For each batch of the certified standard sample, the molecular weight and molecular weight characteristics are calculated in 2 parallel definitions, and a representative chromatogram is presented. The values of the relative standard deviation of the molecular weight of the samples and the content of the controlled fractions did not exceed 2.5 %. A detailed analysis of the molecular weight distribution showed the "classical" dependence of RSD (relative standard deviation) from the average value with a significant increase up to 30 % for small fraction values (less than 0.5 %). It was found that during 16 months at a storage temperature below 8 ºC, the molecular weight and molecular weight characteristics of standard samples of low molecular weight heparin did not significantly change. However, in the SSE solution at a storage temperature of minus 40 °C for 6 months, they degraded by more than 10 %.Conclusion. According to the results of the study, a protocol has been developed for obtaining a standard sample of low-molecular-weight heparin for the standardization of the calcium nadroparin substance according to the indicator "molecular weight distribution". The established shelf life of the sample is at least 16 months at temperatures below 8 °C. The stability of solutions of the standard sample at a storage temperature of –40 °C for 3 months is shown.

P.029 Endovascular therapy for cerebral venous thrombosis: an international survey

Background: Cerebral venous thrombosis (CVT) is a rare cause of stroke, with 10–15% of patients experiencing dependence or death. The role of endovascular therapy (EVT) in the management of CVT remains controversial and practice patterns are not well-known. Methods: We distributed a comprehensive 53-question survey to neurologists, neuro-interventionalists, neurosurgeons and other relevant clinicians globally from May 2023 to October 2023. The survey asked about practice patterns and perspectives on EVT for CVT and assessed opinions regarding future clinical trials. Results: The overall response rate was 31% (863 respondents from 2744 invited participants) across 61 countries. A majority (74%) supported use of EVT for certain CVT cases. Key considerations for EVT included worsening level of consciousness (86%) and other clinical deficits (76%). Mechanical thrombectomy with aspiration (22%) and stent retriever (19%) were the most utilized techniques, with regional variations. Post-procedurally, low molecular weight heparin was the predominant anticoagulant administered (40%), although North American respondents favored unfractionated heparin. Most respondents supported future trials of EVT (90%). Conclusions: Our survey reveals significant heterogeneity in approaches to EVT for CVT, highlighting the necessity for adequately powered clinical trials to guide standard-of-care practices.

#949 Factor XIIa inhibitory antibody does not provide sufficient anticoagulation in ex vivo hemodialysis

Abstract Background and Aims Unfractionated heparin (UFH) and low molecular-weight heparin (LMWH) are the most commonly used anticoagulants in haemodialysis (HD). While effective in preventing clotting, they are also associated with complications including increased risk of bleeding and heparin induced thrombocytopenia. The contact activation system is commonly assumed to be the main trigger of coagulation during HD, through autoactivation of factor (F)XII upon contact with the dialyser. FXII deficient individuals do not have an increased risk of bleeding which makes activated FXII (FXIIa) an attractive drug target as it has the potential to inhibit clotting without disrupting haemostasis. The aim of the study was to evaluate the efficacy of CSL312, a monoclonal, humanized IgG4 antibody against activated FXII (FXIIa), in preventing intradialytic coagulation. Method An ex vivo haemodialysisis model was used to test the efficacy of CSL312 as an anticoagulant. CSL312 (400 µg/mL) was compared to standard doses of UFH, LMWH and citrate anticoagulation. The antibody was provided by CSL Limited. Anticoagulant-free haemodialysisis was used as control. Whole-blood was collected from 12 healthy adult donors in blood-transfer bags containing citrate to prevent clotting before dialysis. Each donor provided blood for two HD-sessions, using different anticoagulants. The blood was dialyzed for one hour through paediatric polysulfone high-flux dialysers. Right before the start of HD, calcium was added to reverse the anticoagulant effect of citrate, except in the citrate group. Blood was sampled before and at 5, 15, 30 and 60 minutes after HD start. To quantify the activity of the contact system, the concentrations of enzyme-inhibitor complexes of antithrombin (AT) or C1-inhibitor (C1INH) in conjunction with FXIIa, FXIa, kallikrein, MASP-1, MASP-2 and thrombin were measured in plasma using enzyme-linked immunosorbent assays. Results Using CSL312 to inhibit FXIIa protease activity (n = 5), clotting occurred in all tests (at 30, 31, 36, 49 and 50 minutes) with a mean clotting time of 39.2 minutes compared to 17 and 30 minutes using no anticoagulation (n = 2). No clotting was evident with other anticoagulants. Using CSL312, the plasma concentration of FXIIa-C1INH at 15 minutes was significantly higher than at baseline (mean 26.2 (SD 9.08) vs mean 17.6 (SD 10.6) µg/mL, p = 0.011). Conclusion FXIIa inhibition using a monoclonal antibody does not provide sufficient anticoagulation during HD. This suggests that the contact system may not be solely responsible for clotting during HD.

Use of defibrotide in COVID-19 pneumonia: comparison of a phase II study and a matched real-world cohort control.

The coronavirus disease 2019 (COVID-19) pandemic led to an unprecedented burden on healthcare systems around the world and a severe global socioeconomic crisis, with more than 750 million confirmed cases and at least 7 million deaths reported by 31st December 2023. The DEFI-VID19 study (ClinicalTrials.gov NCT04335201), a phase II, single-arm, multicenter, open-label trial was designed in mid-2020 to assess the safety and efficacy of defibrotide in treating patients with COVID-19 pneumonia. Defibrotide was administered at a dose of 25 mg/kg/d intravenously, divided into four daily doses over a planned 14-day period for patients with COVID-19 pneumonia receiving non-invasive ventilation. The primary endpoint was Respiratory Failure Free Survival (RFFS); Overall Survival (OS), the number of post-recovery days, and adverse events were the secondary endpoints. For comparison, a contemporaneous control cohort receiving standard of care only was retrospectively selected by applying the eligibility criteria of the DEFI-VID19 trial. To adjust for the imbalance between the two cohorts in terms of baseline variable distributions, an outcome regression analysis was conducted. In adjusted analysis, patients receiving defibrotide reported a trend towards higher RFFS (HR=0.71[0.95CI: 0.34 to 1.29, P= .138]) and OS (HR=0.78[0.95CI: 0.33 to 1.53, P= .248]) and showed a significantly increased number of post-recovery days (difference in means: 3.61[ 0.95CI: 0.97 to 6.26, P= .0037]). Despite concomitant thromboprophylaxis with low molecular weight heparin, the safety profile of defibrotide proved to be favorable. Taken together, our findings suggest that defibrotide may represent a valuable addition to the COVID-19 therapeutic options.

#1912 Assessment of the dynamics of renal anemia in patients with atrial fibrillation and chronic kidney disease stage IIIb-V during anticoagulant therapy

Abstract Background and Aims Therapy with oral anticoagulants prevents the development of most ischemic strokes and systemic embolisms in patients with atrial fibrillation (AF) and chronic kidney disease (CKD), and also helps to increase life expectancy, improving its quality. It should be emphasized that with CKD, the risk of hemorrhagic complications also increases, which in turn can lead to the progression of renal anemia and deterioration in the patient's general condition. The main complication of anticoagulants is an increased risk of major bleeding, including intracranial, life-threatening bleeding. The purpose of the study is to assess the benefits and risks of anticoagulant therapy in patients with renal anemia in AF and stage IIIb-V CKD. Method From February 2022 to July 2023, 2983 patients with AF were admitted to cardiology departments. The majority of patients with AF had hypertension (94%), chronic heart failure (71%), coronary heart disease (65%), and type 2 diabetes mellitus (23%). CKD was diagnosed according to KDIGO criteria, glomerular filtration rate (GFR) was calculated using the CKD-EPI formula. Indications for anticoagulant therapy (ACT) were determined according to European guidelines for AF using the scales for assessing the risk of thromboembolic complications (TEC)—CHA2DS2-VASc and the risk of bleeding—HAS-BLED. Results GFR up to 45 ml/min/1.73 m2 was detected in 2189 (73%) patients with AF, GFR less than 45 ml/min/1.73 m2 in 794 (27%) patients with AF (CKD stages IIIb–V in 516 (65%) cases, for the first identified sustained decrease in glomerular filtration rate (FISD in GFR) of less than 45 ml/min/1.73 m2 was detected in 278 (35%) cases). Among patients with AF and CKD, renal anemia was diagnosed in 23% of cases, in 63% (n = 505) of cases with AF and GFR <45 ml/min/1.73 m2. With a GFR of 45-30 ml/min/1.73 m2, renal anemia was detected in 59%, with a GFR of 30-15 ml/min/1.73 m2—in 89%, with a GFR <15 ml/min/1.73 m2—in 97%, with FISD in GFR <45 ml/min/1.73 m2—in 51%. When stratifying thromboembolic risk according to the CHA2DS2-VASc scale in patients with AF and CKD stages IIIb–V, 0-1 points were scored by 1% (n = 11), 2-5 points by 53% (n = 420), ≥6 points by 46% (n = 363) patients. The results of the analysis of the risk of bleeding according to the HAS-BLED scale showed the following data: 0-1 point—8% (n = 64), 2 points—15% (n = 118), ≥3 points—77% (n = 612). When studying the frequency of ACT prescription, it was revealed that rivaroxaban was prescribed in 21%, apixaban—22%, dabigatran—10%, warfarin—25%, low molecular weight heparins—3%, ACT not recommended—9%, ACT of choice—10% of cases (Table 1). In mild renal anemia (in 39% of patients), taking ACT led to a reduction in the risk of developing TEC—RR 0.55 with 95% CI 0.38-0.79; in case of moderate renal anemia (in 47.3% of patients), the risk of TEC did not decrease RR 1.03 with 95% CI 0.69-1.58; with severe renal anemia (in 13.7% of patients), the risk of TEC was also not reduced—RR 1.6 with 95% CI 1.17-2.2). Conclusion Every fourth patient in the cardiology department with AF showed a decrease in GFR <45 ml/min/1.73 m2, while 1/3 of them had FISD in GFR <45 ml/min/1.73 m2, and it is in these patients that the most common the dose of the prescribed anticoagulant did not correspond to the GFR; 50% of patients with GFR <45 ml/min/1.73 m2 and 32% with GFR <30 ml/min/1.73 m2 are recommended to use direct oral anticoagulants. Patients with stage V CKD were not prescribed direct oral anticoagulants; in 50% of cases, none of the anticoagulants was recommended.

Pancreatic Cancer and Venous Thromboembolism

Pancreatic ductal adenocarcinoma (PDAC) accounts for more than 90% of all pancreatic cancers and is the most fatal of all cancers. The treatment response from combination chemotherapies is far from satisfactory and surgery remains the mainstay of curative strategies. These challenges warrant identifying effective treatments for combating this deadly cancer. PDAC tumor progression is associated with the robust activation of the coagulation system. Notably, cancer-associated thrombosis (CAT) is a significant risk factor in PDAC. CAT is a concept whereby cancer cells promote thromboembolism, primarily venous thromboembolism (VTE). Of all cancer types, PDAC is associated with the highest risk of developing VTE. Hypoxia in a PDAC tumor microenvironment also elevates thrombotic risk. Direct oral anticoagulants (DOACs) or low-molecular-weight heparin (LMWH) are used only as thromboprophylaxis in PDAC. However, a precision medicine approach is recommended to determine the precise dose and duration of thromboprophylaxis in clinical setting.

#2147 Enoxaparin dosing in advanced chronic kidney disease: importance of monitoring with anti-Xa levels

Abstract Background and Aims Enoxaparin is a low-molecular-weight heparin (LMWH) that is commonly used in the prevention of deep venous thrombosis (DVT) and the treatment of acute thomboembolic diseases. Current literature indicates that in advanced chronic kidney disease (CKD), there is a reduced clearance and increased half-life of LMWH and therefore, a dose adjustment is recommended. The prescription label recommends a dose adjustment of enoxaparin to 0.5 mg/kg/day for prophylaxis of DVT and 1 mg/kg/day for therapeutic anticoagulation when eGFR <30 ml/min. The aim of this study was to examine the accuracy of this dosing strategy to achieve the desired target of anticoagulation in advanced CKD. Method We conducted a prospective study in patients admitted from May 2019 to April 2023 in the Nephrology ward at our centre, who started anticoagulant treatment with enoxaparin during their in-hospital stay for prophylactic or therapeutic indications. We excluded patients with eGFR >30 ml/min at the onset of anticoagulation with enoxaparin. The dosing strategy was 0.5 mg/kg/day for prophylaxis of DVT and 1 mg/kg/day for therapeutic anticoagulation in all patients. Blood samples were drawn 4 hours after the third dose of enoxaparin to monitor anti-Xa levels in all cases. Results The study included 153 patients; 70 patients with stage 4-5 CKD and 83 patients on renal replacement therapy. 132 patients (86.3%) received enoxaparin for a therapeutic indication, while 21 patients (13.7%) received it as prophylaxis of DVT. In patients receiving enoxaparin for a therapeutic indication, 73 patients (55.3%) reached the therapeutic target anti-Xa levels (0.6-1), while 32.6% of patients had peak anti-Xa levels below the therapeutic target (<0.6) and 12.1% were over-anticoagulated (>1). There was an inverse relationship between the proportion of patients who were adequately anticoagulated and CKD stage; 66.7%, 58.6% and 48.6% of patients reached the target peak anti-Xa levels in CKD stage 4, 5 and 5D respectively. There was no significant association between anti-Xa levels and obesity or liver disease. In patients receiving enoxaparin for prophylaxis of DVT, 42.9% reached the target anti-Xa levels for prophylaxis (0.3-0.6), while 38.1% had anti-Xa levels below this range and 19% were over-anticoagulated. Conclusion The enoxaparin dosing recommendations indicated by its label entails a high proportion of patients with advanced CKD who do not achieve the target therapeutic levels of antiXa, especially in patients on renal replacement therapy. To ensure adequate anticoagulation in these patients, we recommend using individualized dosing adjustments based on monitoring of anti-Xa levels for the prevention of thromboembolic events and reducing the risk of hemorrhagic events.

Glass bead-activated clotting time (gb-ACT) for monitoring the anticoagulation effects in elderly patients with high risk of venous thromboembolism (VTE)

ABSTRACT Background To find a new bedside method to monitor the anticoagulation effects of low-molecular-weight heparins (LMWHs) in patients with a high risk of venous thromboembolism (VTE). Research design and methods A total of 32 hospitalized patients (aged ≥60 years) who were at high risk of VTE were assigned to receive subcutaneous LMWH for 5 to 14 days. Plasma anti-factor Xa (anti-Xa) activity was conducted by a chromogenic method, and the glass bead-activated whole blood clotting time (gb-ACT) value was obtained by a Sonoclot Analyzer. Results A correlation between the gb-ACT values and the anti-Xa levels was suggested (R = 0.447, p = 0.002), and it was stronger in the older group aged 80 years above (R = 0.467, p = 0.008) and in the group of patients with an eGFR of 30 ~ 60 mL/min (R = 0.565, p = 0.005). The area under the curve (AUC) for gb-ACT by receiver operating characteristic (ROC) curve evaluation was 0.725 (p = 0.011), and the gb-ACT >282.5s provided a sensitivity of 60% and specificity of 74% for anti-Xa >0.800 IU/ml. Conclusions The gb-ACT values detected by a Sonoclot Analyzer could act as a novel bedside method in the monitoring of LMWH anticoagulation.

Primary prevention of venous thromboembolism with low molecular weight heparins in surgical patients – 2024: Council of Experts resolution

On March 15, 2024, in Moscow, the Russian Phlebological Association and the National Association of Specialists in Thrombosis, Clinical Hemostasiology and Hemorheology organized a meeting of the Council of Experts during the Russian Forum on Thrombosis and Hemostasis on the acute issues of venous thromboembolism (VTE) primary prevention using low molecular weight heparins (LMWH) in surgical patients with different body weight. The participants reviewed the relevance and prevalence of this problem in surgical practice, discussed risk factors and the frequency of VTE development, including bleeding in the postoperative period, and the Caprini risk score for complications. The discussion also focused on standard and personalized LMWH doses for primary prophylaxis of VTE in the perioperative period in surgical patients, depending on body weight, and the role of laboratory tests, including assessment of LMWH anti-Xa activity for monitoring the efficacy and safety of VTE primary prevention in clinical practice.

Pelvic vein thrombosis in patients with pelvic venous disorders.

To assess the incidence of pelvic vein thrombosis (PVT) and outcomes of anticoagulant therapy for PVT in patients with pelvic venous disorders (PeVDs). This prospective cohort study included 588 female patients with PeVDs underwent clinical examination followed by duplex ultrasound of the pelvic veins in 2021-2023. Patients with PVT were administered with anticoagulant therapy in an outpatient setting using low molecular weight heparins at a therapeutic dose. PVT was detected in 7.6% of patients with PeVDs and was symptomatic in 28.8% of them. The majority of asymptomatic patients had thrombosis in only one of the parametrial veins (90.6%). Anticoagulant therapy resulted in the PVT symptoms relief in all patients within 10 days and recanalization of the pelvic veins in 1-3 months. In our study, PVT was diagnosed in 7.6% of patients with PeVDs. Anticoagulant therapy is effective and safe in resolving PVT symptoms.

Meta-analysis of new intervention measures for preventing side effects of artificial joint replacement

BACKGROUND Intertrochanteric fracture of the femur occurs mostly among older people, and seriously affects daily life and quality of life. At present, physical intervention, drug treatment, routine intervention and rehabilitation training are widely used for prevention of side effects, but it is still inconclusive which intervention has the best effect. AIM To compare the effects of new intervention measures for preventing side effects of artificial joint replacement. METHODS We searched the Chinese and English literatures for comparative studies on the prevention of side effects of new interventions for artificial joint replacement from July 2013 to June 2023 in China HowNet, PubMed, Wanfang, Weipu and other databases. Study quality was evaluated by improved Jadad scoring standard, and the effects of different interventions on preventing different complications were analyzed by meta-analysis of evidence-based medicine with Review Manager 5.0 software. RESULTS Ten articles, including 869 cases, were finally included. The preventive effects of different interventions on the side effects of artificial joint replacement were studied, and valid data were extracted. There were two articles on the preventive effects of drug intervention, four on comparison of the preventive effects of combined and single interventions, and three on the preventive effects of physical intervention, rehabilitation training and routine intervention. Meta-analysis showed that the preventive effect of rivaroxaban was significantly better than low molecular weight heparin calcium [mean difference (MD) = -0.16, 95%CI: -0.28 to -0.04, P < 0.05]. The effect of combined intervention was significantly better than that of single intervention (MD = -0.08, 95%CI: -0.16 to -0.01, P < 0.001). Physical intervention was significantly better than routine intervention and rehabilitation training (MD = 0.26, 95%CI: 0.16–0.36, P < 0.001). CONCLUSION Rivaroxaban combined with rehabilitation training is preferred for preventing deep vein thrombosis after artificial joint replacement. In the prevention of pulmonary embolism, rivaroxaban drug intervention is given priority. The effect of combined intervention is better than that of single intervention.

Factor XI inhibitors: a new option for the prevention and treatment of cancer-associated thrombosis

Venous thromboembolism (VTE) is a relatively common complication in cancer patients with potentially dire consequences. Anticoagulants are the mainstay of treatment of cancer-associated VTE. The anticoagulants most often used are low-molecular-weight heparin (LMWH) and direct oral factor (F) Xa inhibitors, which include apixaban, edoxaban, and rivaroxaban. Most guidelines recommend primary VTE prophylaxis with LMWH, apixaban, or rivaroxaban after abdominal or pelvic cancer surgery, or in high-risk ambulatory cancer patients. Both oral FXa inhibitors and LMWH have limitations. LMWH requires daily subcutaneous injections, and because of its renal clearance, its use may be problematic in patients with severe kidney disease. The risk of bleeding with oral FXa inhibitors may be higher than with LMWH in patients with intraluminal gastrointestinal or genitourinary cancers. Other problems with oral FXa inhibitors include potential drug-drug interactions and dosing issues in patients with thrombocytopenia or severe kidney or liver disease. Therefore, there remains a need for convenient and safer anticoagulants for VTE treatment in cancer patients. FXI has emerged as a potentially safer target for anticoagulants than FXa because FXI is essential for thrombosis, but mostly dispensable for hemostasis. This review summarizes the currently available therapeutic options for cancer-associated VTE, highlights knowledge gaps, and discusses the potential of FXI inhibitors to address key unmet clinical needs in this vulnerable patient population.

AN ACUTE MYOCARDIAL INFARCTION IN A VERY YOUNG MAN DUE TO HYPERHOMOCYSTEINEMIA

Abstract Introduction A young 17–year–old boy smoker and obese was admitted to our cardiology unit for continuous oppressive chest pain radiating to the left arm that had arisen three days earlier. In the emergency room, he had performed blood tests with evidence of an increased troponin and an electrocardiogram that showed mild ST–elevation in inferior leads with ST depression in aVL. We performed an urgent transthoracic echocardiography examination that was unremarkable Investigation Once diagnosed with acute ST–segment elevation myocardial infarction, the patient underwent emergency coronary angiography. Coronary angiography highlighted an intermediate stenosis of the first branch diagonal to the proximal tract and a possible occlusion of the periapical branch of the anterior descending artery. It was decided not to perform PTCA as we could not exclude a distal coronary dissection and considering the vessel was of small caliber. We decided to complete the diagnostic process by performing a cardiac MRI showing edema in the apex and distal inferior wall and transmural gadolinium enhancement at the level of the septum and inferior wall of the distal section. In the context of the damaged wall a focal area of hypointensity to be referred to the "no–reflow" phenomenon Management The patient was treated with DAPT, low molecular weight heparin and high dose statin. A few hours after the coronary angiography the patient stopped having chest pain and remained asymptomatic for the rest of the hospital stay. We performed complete blood tests including with evidence of hyperhomocysteinemia. The lipid panel was normal. Hematological consultation recommended folate and Vitamine B12 treatment. After 12 months the patient is asymptomatic, has stopped smoking and continues to take DAPT. He repeated the echocardiogram which showed no alterations. Genetic testing was performed after hospital discharge and was positive for Methylenetetrahydrofolate reductase (MTHFR) homozygous mutation Conclusion Our clinical case shows a rare case of acute myocardial infarction in a very young person. Diagnosis and treatment were complicated by the extreme distality of the occlusion and the few modifiable risk factors identified (smoker, obesity and hyperhomocysteinemia). Hyperhomocysteinemia is an often underestimated cardiovascular risk factor associated with a high risk of cardiovascular events and multivessel coronary disease that should be sought in all young patients with AMI.

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.

Association of timing and agent for VTE prophylaxis in patients with severe traumatic brain injury on VTE, mortality, neurosurgical intervention, and discharge disposition.

Trauma patients are at increased risk for venous thromboembolism events (VTE). The decision of when to initiate VTE chemoprophylaxis (VTEP) and with what agent remains controversial in patients with severe traumatic brain injury (TBI). This comparative effectiveness study evaluated the impact of timing and agent for VTEP on outcomes for patients with severe TBI (AIS Head = 3,4, or 5). Data was collected at 35 Level 1 and 2 trauma centers from January 1, 2017 to June 1, 2022. Patients were placed into analysis cohorts: No VTEP, low-molecular weight heparin (LMWH) ≤ 48 hours, LMWH>48 hours, Heparin≤48 hours, Heparin>48 hours. Propensity score matching accounting for patient factors and injury characteristics was used with logistic regression modeling to evaluate in-hospital mortality, VTE events, and discharge disposition. Neurosurgical intervention after initiation of VTEP was used to evaluate extension of intracranial hemorrhage. Of 12,879 patients, 32% had no VTEP, 36% LMWH, and 32% Heparin. Overall mortality was 8.3% and lowest among patients receiving LMWH≤48 hours (4.1%). VTE rates were lower with use of LMWH (1.6 vs 4.5%, OR 2.98, 95% CI 1.40-6.34, p = 0.005) without increasing mortality or neurosurgical interventions. VTE rates were lower with early prophylaxis (2.0 vs 3.5%, OR 1.76, 95% CI 1.15-2.71, p = 0.01) without increasing mortality (p = 1.0). Early VTEP was associated with more non-fatal intracranial operations (p < 0.001). However, patients undergoing neurosurgical intervention after VTEP initiation had no difference in rates of mortality, withdrawal of care, or unfavorable discharge disposition (p = 0.7, p = 0.1, p = 0.5). In patients with severe TBI, LMWH usage was associated with lower VTE incidence without increasing mortality or neurosurgical interventions. Initiation of VTEP≤48 hours decreased VTE incidence and increased non-fatal neurosurgical interventions without affecting mortality. LMWH is the preferred VTEP agent for severe TBI, and initiation ≤48 hours should be considered in relation to these risks and benefits. Therapeutic/Care Management, Level III.

Comparison of rivaroxaban and low molecular weight heparin in the treatment of cancer-associated venous thromboembolism: a Swedish national population-based register study.

Treating cancer-associated venous thromboembolism (CAT) with anticoagulation prevents recurrent venous thromboembolism (rVTE), but increases bleeding risk. To compare incidence of rVTE, major bleeding, and all-cause mortality for rivaroxaban versus low molecular weight heparin (LMWH) in patients with CAT. We developed a cohort study using Swedish national registers 2013-2019. Patients with CAT (venous thromboembolism within 6 months of cancer diagnosis) were included. Those with other indications or with high bleeding risk cancers were excluded (according to guidelines). Follow-up was from index-CAT until outcome, death, emigration, or end of study. Incidence rates (IR) per 1000 person-years with 95% confidence interval (CI) and propensity score overlap-weighted hazard ratios (HRs) for rivaroxaban versus LMWH were estimated. We included 283 patients on rivaroxaban and 5181 on LMWH. The IR for rVTE was 68.7 (95% CI 40.0-109.9) for rivaroxaban, compared with 91.6 (95% CI 81.9-102.0) for LMWH, with adjusted HR 0.77 (95% CI 0.43-1.35). The IR for major bleeding was 23.5 (95% CI 8.6-51.1) for rivaroxaban versus 49.2 (95% CI 42.3-56.9) for LMWH, with adjusted HR 0.62 (95% CI 0.26-1.49). The IR for all-cause mortality was 146.8 (95% CI 103.9-201.5) for rivaroxaban and 565.6 (95% CI 541.8-590.2) for LMWH with adjusted HR 0.48 (95% CI 0.34-0.67). Rivaroxaban performed similarly to LMWH for patients with CAT for rVTE and major bleeding. An all-cause mortality benefit was observed for rivaroxaban which potentially may be attributed to residual confounding. NCT05150938 (Registered 9 December 2021).

C-reactive protein level at admission is associated with increased mortality in critically ill cardiac patients with heparin-induced thrombocytopenia

Abstract Funding Acknowledgements None. Introduction Heparin-induced thrombocytopenia (HIT) is a rare immune-mediated disorder related to the use of unfractionated heparin or low-molecular weight heparin. As heparin is commonly used in critically ill cardiac patients, HIT consititute a relevant clinical issue in the intensive cardiac care unit. Despite this, there isn't any known factor that could predict mortality in acute cardiac patients with heparin-induced thrombocytopenia. Purpose The purpose of our study was to verify if any clinical or laboratory factor could predict mortality in critically ill cardiac patients with heparin-induced thrombocytopenia. Methods We retrospectively collected data of all patients with HIT who were hospitalized in our intensive cardiac care unit in 2016-2023. We had used functionalized latex immunoassay to confirm the diagnosis of HIT. We performed statistical analysis including clinical and laboratory variables to find any predictor of mortality in critically ill cardiac patients with HIT. Results Among 22 483 patients hospitalized in 2016-2023 in our department of cardiology 12 were diagnosed with HIT. 4 of them died during index hospitalization and 8 survived. Among clinical and laboratory characteristics only C-reactive protein level at admission was associated with increased mortality in acute caridac patients with HIT. Non-survivors had higher CRP levels at admission as compared to survivors, 190 [125-247] mg/l vs. 22 [9-71] mg/l respectively (p = 0,03). Conclusions C-reactive protein level at admission is associated with increased mortality in critically ill cardiac patients with HIT. Initial underlying systemic inflammatory response may constitute the precipitating factor of unfavorouble outcome in acute cardiac patients with heparin-induced thrombocytopenia. Further studies are necessary to confirm these findings.

Risk Assessment of Critical Obstetric Bleeding With Low-Molecular-Weight Heparin.

Use of unfractionated heparin (UFH) during the peripartum period is considered to be a higher risk of critical obstetric bleeding compared to low-molecular-weight heparin (LMWH). However, the evidence for the safety of using LMWH during the peripartum period is currently lacking. This study retrospectively investigated a nationwide medical database to clarify the safety of using LMWH during childbirth. The Japanese Nationwide Diagnosis Procedure Combination database was retrospectively reviewed, and data from women with childbirth between 2018 and 2022 were collected. Among the overall 354,299 women with childbirth, 3,099 were with obstetric disseminated intravascular coagulation (DIC), 484 were with critical obstetric bleeding requiring massive red blood cell (RBC) transfusion ≥4,000 cc, and 38 were with maternal death. Among the overall women, each of the anticoagulants other than LMWH was associated with critical obstetrical bleeding with an adjusted odds ratio (aOR) greater than 1.0, while LMWH was not associated with critical obstetrical bleeding (aOR, 0.54 (95% confidence interval, 0.11-2.71)). This finding did not change in subgroup analyses among those with Cesarean section. Furthermore, UFH was associated with critical bleeding among the 3,099 women with obstetrical DIC (aOR, 3.91 (2.83-5.46)), while LMWH was not (aOR, 0.26 (0.03-1.37)). The use of UFH was significantly associated with an increased critical obstetric hemorrhage requiring massive RBC transfusion or total hysterectomy. Meanwhile, the use of LMWH was not associated with increased critical obstetric bleeding. LMWH would be safer than UFH to be used for women during childbirth.

Factor Xa inhibitors versus low molecular weight heparin for preventing coagulopathy following COVID-19: a systematic review and meta analysis of randomized controlled trials

Background: Hospitalized patients with COVID-19 have shown a significant occurrence of thromboembolism and a heightened risk of death. It remains unclear whether factor Xa inhibitors are superior to enoxaparin in this context. Hence, there is a need for a direct comparison to assess the preventive effects and safety of factor Xa inhibitors versus enoxaparin in hospitalized COVID-19 patients. Methods: MEDLINE, Embase, and Cochrane Central databases were searched for randomized controlled trials (RCTs) or retrospective studies that compared the effectiveness or safety of factor Xa inhibitors and enoxaparin in preventing thromboembolism in hospitalized patients with COVID-19. Embolic incidence, incidence of bleeding, and all-cause mortality were among the outcomes of interest. Mantel-Haenszel weighted random-effects model was used to calculate relative risks (RRs) with 95 percent confidence intervals (CIs). Results: The analysis included 6 RCTs and 2 retrospective studies containing 4048 patients. Meta-analysis showed a statistically significant reduction among patients on factor Xa inhibitors compared with LMWH in the embolic incidence (RR 0.64 [95%, CI 0.42, 0.98]; P=0.04, I2=12%). Upon subgroup analysis by type of study design, no significant reductions were noted in patients on factor Xa inhibitors in RCTs (RR: 0.62; 95% CI: 0.33–1.17; P=0.14) or observational studies (RR: 0.53; 95% CI: 0.23–1.26; P=0.15) when compared with enoxaparin Factor Xa inhibitors were not significantly associated with incidence of bleeding (RR 0.76 [95% CI 0.36, 1.61]; P=0.47, I2=0%) or all-cause mortality (RR: 0.81; 95% CI: 0.48–1.36; P=0.43). Consistent results were obtained upon subgroup analysis by the type of study design. Conclusion: Factor Xa inhibitors are more effective than enoxaparin in preventing thromboembolism among patients with COVID-19 who are not acutely ill and are hospitalized. Additional rigorous randomized controlled trials (RCTs) comparing factor Xa inhibitors with enoxaparin are warranted.

Anticoagulants versus Antiplatelet Treatment in the Medical Management of Carotid Floating Thrombus

Carotid free-floating thrombus (CFT) is a rare cause of stroke describing an intraluminal thrombus that is loosely associated with the arterial wall and manifesting as a filling defect fully surrounded by flow on vascular imaging. Unfortunately, there is no clear consensus among experts on the ideal treatment for this pathology. Retrospective analysis of acute ischemic stroke (AIS) and transient ischemic attack (TIA) patients diagnosed with CFT on computed tomography angiogram (CTA) between January 2015-March 2023. We aimed to compare two treatment regimens: anticoagulation (ACT) and antiplatelet (APT) in the treatment of CFT. APT regimens included the use of dual or single antiplatelets (DAPT or SAPT; aspirin, clopidogrel and ticagrelor) and ACT regimens included the use of direct oral anticoagulants, warfarin, heparin or low molecular weight heparin +/- ASA. Patients that underwent mechanical thrombectomy were excluded. During study time there were 8252 acute ischemic stroke hospitalizations, of which 135 (1.63%) patients were diagnosed with CFT. Sixty-six patients were included in our analysis. Patients assigned to APT were older (60.41years ± 12.82;p<0.01). Other demographic variables were similar between ACT and APT groups. Complete CFT resolution on repeat vascular imaging was numerically higher at 30 days (58.8 vs 31.6%, respectively; p=0.1) and at latest follow-up (70.8 vs 50%; p=0.1) on ACT vs APT, respectively without reaching statistical significance. Similarly, there was numerically higher rates of any ICH with ACT compared to APT but it did not achieve statistical significance (27.6% vs 13.5%; p=0.5). There were similar rates of PH1/2 hemorrhagic transformation, independence at discharge and similar hospital length of stay between ACT and APT groups. Patients assigned to APT were more likely to be discharged on their assigned treatment compared to those assigned to ACT (86.5 vs 55.2%; p<0.001). The rate of 30-day recurrent stroke was comparable among ACT and APT at 30 days (3.4 vs 0%; p=0.1, respectively). Sensitivity analysis comparing exclusive ACT vs Dual APT lead to similar results. Our study showed comparable efficacy and safety outcomes in CFT patients who were exclusively managed medically with ACT vs APT. Larger prospective studies are needed.