Enoxaparin For Thromboprophylaxis Research Articles

A More Selective vs a Standard Risk-Stratified, Heparin-Based, Obstetric Thromboprophylaxis Protocol

In 2016, our institution adopted a pregnancy-related venous thromboembolism (VTE) prophylaxis protocol based on American College of Obstetricians and Gynecologists guidelines that recommended postpartum heparin-based chemoprophylaxis (enoxaparin) based on a risk-stratified algorithm. In response to increased wound hematomas without significant reduction in VTE using this protocol, a more selective risk-stratified approach was adopted in 2021. To evaluate outcomes of the more selective risk-stratified approach to heparin-based obstetric thromboprophylaxis (enoxaparin) protocol. Retrospective observational study of 17 489 patients who delivered at a single tertiary care center in the southeast US between January 1, 2016, and December 31, 2018 (original protocol), and between December 1, 2021, and May 31, 2023 (more selective protocol). Patients receiving outpatient anticoagulation for active VTE or high VTE risk during pregnancy were excluded. Standard risk-stratified and more selective postpartum VTE chemoprophylaxis protocols. The primary outcome was clinical diagnosis of wound hematoma up to 6 weeks pos tpartum. The secondary outcome was new diagnosis of VTE up to 6 weeks post partum. We compared baseline characteristics and outcomes between groups and estimated adjusted odds ratios with 95% CIs of primary and secondary outcomes using the original protocol group as reference. Of 17 489 patients included in the analysis, 12 430 (71%) were in the original protocol group and 5029 (29%) were in the more selective group. Rates of chemoprophylaxis decreased from 16% (original protocol) to 8% (more selective protocol). Patients in the more selective group were more likely to be older, be married, and have obesity or other comorbidities (hypertension, diabetes, cardiac disease). Compared with the original protocol, the more selective protocol was associated with a decrease in any wound hematoma (0.7% vs 0.3%; adjusted odds ratio [aOR], 0.38; 95% CI, 0.21-0.67), specifically due to a lower rate of superficial wound hematomas (0.6% vs 0.3%; aOR, 0.43; 95% CI, 0.24-0.75). There was no significant increase in VTE or individual types of VTE (0.1% vs 0.1%; aOR, 0.40; 95% CI, 0.12-1.36). A more selective risk-stratified approach to an enoxaparin thromboprophylaxis protocol for VTE was associated with decreased rates of wound hematomas without increased rates of postpartum VTE.

Cost-effectiveness of enoxaparin versus aspirin in the prevention of venous thromboembolism after total hip or knee arthroplasty: an analysis from the CRISTAL cluster-randomized trial.

The aim of this study was to evaluate the healthcare costs and benefits of enoxaparin compared to aspirin in the prevention of symptomatic venous thromboembolism (VTE) after total hip arthroplasty (THA) or total knee arthroplasty (TKA) using data from the CRISTAL trial. This trial-based economic analysis reports value for money as incremental cost per quality-adjusted life-year (QALY) gained in 2022 Australian dollars, compared to a single threshold value of AUD$70,000 per QALY. Event costs were estimated based on occurrence of VTEs and bleeds, and on published guidelines for treatment. Unit costs were taken from Australian sources. QALYs were estimated using CRISTAL six-month follow-up data. Sensitivity analyses are presented that vary the cost of VTE treatment, and extend the analyses to two years. The CRISTAL trial found that enoxaparin was more effective than aspirin in preventing symptomatic VTE within 90 days of THA or TKA (risk difference 1.97% (95% confidence interval (CI) 0.54% to 3.41%; p = 0.007)). The additional cost after a THA or TKA was AUD$83 (95% CI 68 to 97) for enoxaparin, and enoxaparin resulted in an additional 0.002 QALYs (95% CI -0.002 to 0.005). Incremental cost per QALY gained was AUD$50,567 (95% CI 15,513, dominated) for enoxaparin. We can be 60% confident that the incremental cost per QALY does not exceed the willingness-to-pay threshold of AUD$70,000. Increasing the cost of VTE treatment and extension of costs and consequences to two years suggested greater confidence that enoxaparin is good value for money (70% and 63% confidence, respectively). This analysis provides strong evidence that enoxaparin thromboprophylaxis following THA or TKA reduced VTEs, but weak evidence of net economic benefits over aspirin. If the value of avoiding VTEs is high, and there is a strong likelihood of VTE-related health impairments, we can be more confident that enoxaparin is cost-effective compared to aspirin.

Enoxaparin thromboprophylaxis in hospitalized obese pediatric patients.

Enoxaparin is an anticoagulant used for pharmacologic thromboprophylaxis in pediatrics. Enoxaparin pharmacokinetics can be altered in the setting of obesity. Optimal enoxaparin dosing for thromboprophylaxis in children with obesity remains unclear. A retrospective review was conducted of pediatric patients who weighed ≥60kg with BMI≥95th percentile, received enoxaparin for thromboprophylaxis, and had at least one appropriately drawn anti-factor Xa(anti-Xa) from 2013 to 2022. Anti-Xa levels were reviewed for patients initially treated with enoxaparin 30mg every 12h. The average daily enoxaparin dose required to achieve an anti-Xa of 0.2-0.4 unit/mL, which was stratified by BMI percentile and weight, was calculated. Of 116 patients (median age 15.8 years) included for analysis, 106 patients were initially treated with enoxaparin 30mg every 12h. Anti-Xa levels were<0.2 unit/mL in 53% of patients with BMI>99th percentile and 54% of patients>100kg. Ninety-one patients had at least one anti-Xa 0.2-0.4unit/mL with an average daily enoxaparin dosing of 66mg. When stratified by severity of obesity, higher doses were required to attain an anti-Xa 0.2-0.4 unit/mL in patients with BMI>99th percentile compared with those with 95th-99th percentile (67.8±15.7 vs. 62±5.6mg/day, p=.01). Patients>100kg required significantly higher dose than those ≤100kg (69.1±15.5 vs 61.2±7.3mg/day, p=.002). Increased initial dosing and/or anti-Xa level monitoring should be considered in adolescents with severe obesity receiving enoxaparin thromboprophylaxis.

Weight-based enoxaparin thromboprophylaxis in young trauma patients: analysis of the CLOTT-1 registry

IntroductionOptimal venous thromboembolism (VTE) enoxaparin prophylaxis dosing remains elusive. Weight-based (WB) dosing safely increases anti-factor Xa levels without the need for routine monitoring but it is unclear if it leads...

Enoxaparin for VTE thromboprophylaxis during inpatient rehabilitation care: assessment of the standard fixed dosing regimen

BackgroundWe aimed to examine the efficiency of fixed daily dose enoxaparin (40 mg) thromboprophylaxis strategy for patients undergoing inpatient rehabilitation.MethodsThis was an observational, prospective, cohort study that included 63 hospitalized patients undergoing rehabilitative treatment following sub-acute ischemic stroke (SAIS) or spinal cord injury (SCI), with an indication for thromboprophylaxis. Anti-Xa level measured three hours post-drug administration (following three consecutive days of enoxaparin treatment or more) was utilised to assess in vivo enoxaparin activity. An anti-Xa level between 0.2-0.5 U/ml was considered evidence of effective antithrombotic activity.ResultsWe found sub-prophylactic levels of anti-Xa (<0.2 U/ml) in 19% (12/63). Results were within the recommended prophylactic range (0.2-0.5 U/ml) in 73% (46/63) and were supra-prophylactic (>0.5 U/ml) in 7.9% (5/63) of patients. Anti-Xa levels were found to inversely correlate with patients’ weight and renal function as defined by creatinine clearance (CrCl) (p<0.05).ConclusionsOur study confirmed that a one-size-fits-all approach for venous thromboembolism (VTE) prophylaxis may be inadequate for rehabilitation patient populations. The efficacy of fixed-dose enoxaparin prophylaxis is limited and may be influenced by renal function and weight. This study suggests that anti-Xa studies and prophylactic enoxaparin dose adjustments should be considered in certain patients, such as those who are underweight, overweight and or have suboptimal renal function.Trial registrationNo. NCT103593291, registered August 2018.

Efficacy and Safety of Apixaban and Enoxaparin for Thromboprophylaxis after Total Hip Arthroplasty

Efficacy and Safety of Apixaban and Enoxaparin for Thromboprophylaxis after Total Hip Arthroplasty

Event rates and risk factors for venous thromboembolism and major bleeding in a population of hospitalized adult patients with acute medical illness receiving enoxaparin thromboprophylaxis

BackgroundWe aimed to describe the event rates and risk-factors for symptomatic venous thromboembolism (VTE) and major bleeding in a population of hospitalized acutely ill medical patients. MethodsPatients ≥40 years old and hospitalized for acute medical illness who initiated enoxaparin prophylaxis were selected from the US Optum research database. Rates of symptomatic VTE and major bleeding at 90-days were estimated via the Kaplan-Meier (KM) method. Risk factors were identified via the Cox proportional hazards model. ResultsA total of 123,022 patients met the selection criteria. The KM rates of VTE and major bleeding at 90-days were 3.5 % and 2.2 %, respectively. Among subgroups, the risk of VTE varied from 3.0 % in patients with ischemic stroke to 6.9 % in patients with a cancer-related hospitalization, and the risk of major bleeding varied from 1.9 % in patients with inflammatory conditions to 3.6 % in patients with ischemic stroke. Key risk factors for VTE were prior VTE (HR=4.15, 95 % confidence interval [CI] 3.80–4.53), cancer-related hospitalization (HR=2.35, 95 % CI 2.10–2.64), and thrombophilia (HR=1.64, 95 % CI 1.29–2.08). Key risk factors for major bleeding were history of major bleeding (HR=2.17, 95 % CI 1.72–2.74), history of non-major bleeding (HR=2.46, 95 % CI 2.24–2.70), and hospitalization for ischemic stroke (2.42, 95 % CI 2.11–2.78). ConclusionThere is substantial heterogeneity in the event rates for VTE and major bleeding in acute medically ill patients. History of VTE and cancer related hospitalization represent profiles with a high risk of VTE, where continued VTE prophylaxis may be warranted.

Enoxaparin for symptomatic COVID-19 managed in the ambulatory setting: An individual patient level analysis of the OVID and ETHIC trials

BackgroundAntithrombotic treatment may improve the disease course in non-critically ill, symptomatic COVID-19 outpatients. MethodsWe performed an individual patient-level analysis of the OVID and ETHIC randomized controlled trials, which compared enoxaparin thromboprophylaxis for either 14 (OVID) or 21 days (ETHIC) vs. no thromboprophylaxis for outpatients with symptomatic COVID-19 and at least one additional risk factor. The primary efficacy outcome included all-cause hospitalization and all-cause death within 30 days from randomization. Both studies were prematurely stopped for futility. Secondary efficacy outcomes were major symptomatic venous thromboembolic events, arterial cardiovascular events, or their composite occurring within 30 days from randomization. The same outcomes were assessed over a 90-day follow-up. The primary safety outcome was major bleeding (ISTH criteria). ResultsA total of 691 patients were randomized: 339 to receive enoxaparin and 352 to the control group. Over 30-day follow-up, the primary efficacy outcome occurred in 6.0 % of patients in the enoxaparin group vs. 5.8 % of controls for a risk ratio (RR) of 1.05 (95%CI 0.57–1.92). The incidence of major symptomatic venous thromboembolic events and arterial cardiovascular events was 0.9 % vs. 1.8 %, respectively (RR 0.52; 95%CI 0.13–2.06). Most cardiovascular thromboembolic events were represented by symptomatic venous thromboembolic events, occurring in 0.6 % vs. 1.5 % of patients, respectively. A similar distribution of outcomes between the treatment groups was observed over 90 days. No major bleeding occurred in the enoxaparin group vs. one (0.3 %) in the control group. ConclusionsWe found no evidence for the clinical benefit of early administration of enoxaparin thromboprophylaxis in outpatients with symptomatic COVID-19. These results should be interpreted taking into consideration the relatively low occurrence of events.

Efficacy and Safety of Rivaroxaban and Enoxaparin for Thromboprophylaxis Among Total Hip Arthroplasty Patients: A Systematic Review and Meta-Analysis.

Venous thromboembolism (VTE) is one of the major and potentially life-threatening complications following major orthopedic surgeries. Research evidence comparing the effectiveness of rivaroxaban and enoxaparin for thromboprophylaxis specific to total hip arthroplasty (THA) has been limited. Hence, this review was done to compare the efficacy and safety of rivaroxaban against enoxaparin for thromboprophylaxis after THA. We conducted a search in databases including Medline, EMBASE, ScienceDirect, Google Scholar, and Cochrane Library from inception until May 2021. Randomized controlled trials directly comparing the effectiveness of rivaroxaban and enoxaparin for thromboprophylaxis among patients undergoing THA were eligible for inclusion. Outcome parameters assessed were efficacy in terms of total VTE and all-cause mortality, major VTE, deep vein thrombosis, symptomatic VTE, and safety in terms of major bleeding events, clinically relevant nonmajor bleeding events, minor bleeding events, total bleeding events, drug-related adverse events, and wound infection. We performed a meta-analysis with a random effects model and reported a pooled risk ratio (RR) with a 95% confidence interval (CI). Eleven studies, including 9057 participants, were analyzed. Amongst efficacy outcomes, VTE and all-cause mortality pooled an RR of 0.58 (95% CI: 0.34-0.99), major VTE pooled an RR of 0.37 (95% CI: 0.15-0.90), deep vein thrombosis pooled an RR of 0.57 (95% CI: 0.32-1.02), and symptomatic VTE pooled an RR of 0.51 (95% CI: 0.30-0.87). Amongst safety outcomes, major bleeding events pooled an RR of 1.18 (95% CI: 0.77-1.80), total bleeding events pooled an RR of 1.12 (95% CI: 0.93-1.34), drug-related adverse event pooled an RR of 0.99 (95% CI: 0.87-1.12), and wound infection pooled an RR of 1.11 (95% CI: 0.58-2.14). Rivaroxaban is a more efficacious drug in terms of VTE and all-cause mortality compared to enoxaparin following THA, and rivaroxaban was non-inferior in terms of safety profiles such as wound infection, bleeding, and drug-related adverse events.

Prolonged Elevations of Factor VIII and von Willebrand Factor Antigen After Multisystem Inflammatory Syndrome in Children.

Multisystem Inflammatory Syndrome in Children (MIS-C) is a late systemic inflammatory response to a recent mild or asymptomatic coronavirus disease of 2019 infection. The pathophysiology is incompletely understood but it often features significant coagulopathy along with cardiac and endothelial dysfunction. Endothelial inflammation has been primarily described in acute coronavirus disease of 2019 infection, with less characterization in MIS-C. Here we describe novel findings of nearly universal severe and prolonged factor VIII (FVIII) and von Willebrand factor antigen elevations in an institutional cohort of patients with MIS-C ages younger than or 21 years old (N=31). All patients had elevated acute phase reactants and D-dimer at presentation and met published criteria for MIS-C. FVIII was high at presentation in 97% of patients but continued to rise during the ensuing weeks of treatment to a mean 429%, peaking on median day 17 of illness as an outpatient. FVIII levels were >600% in multiple patients. von Willebrand factor antigen was measured less frequently but showed similar trends. These escalations occurred amidst resolving cardiac dysfunction and acute phase reactant normalization and despite patients receiving multimodal anti-inflammatory treatments and aspirin and enoxaparin thromboprophylaxis. No thrombotic events occurred. Endothelial dysfunction represented by very elevated FVIII levels may persist longer than other acute phase reactants may reflect.

The use of enoxaparin as venous thromboembolism prophylaxis in bariatric surgery: A retrospective cohort study

IntroductionVenous thromboembolism (VTE) is one of the major causes of morbidity and mortality in bariatric patients. The use of low-molecular-weight heparin (LMWH), as enoxaparin, is considered one of the mainstays thromboprophylaxis regimens in postoperative bariatric patients. Despite the universal agreement on the importance of thromboprophylaxis in these patients, there are inadequate strong recommendations for its dosing and duration. The aim of our study is to explore the current practice on using enoxaparin in bariatric patients, as well as to assess both the efficacy and safety of varying dosing regimens. Material and methodsThis is a retrospective cohort study of morbidly obese patients who underwent bariatric procedure at a tertiary care hospital between 2016 and 2019. All adult patients who met the eligibility criteria for bariatric surgery and received enoxaparin with a minimum follow-up period of one month were included in our study. Participants with a history of coagulopathy, renal or hepatic insufficiency were excluded from the study. Data collected include patient demographics, VTE risk factors, and co-morbidities. The outcome of treatment failure was defined as the composite of either VTE or major bleeding. ResultsA total of 1,169 patients who underwent bariatric surgery were included in the study. The mean age was 35.54 years, with mean body mass index (BMI) of 45.78 kg/m2. The mean duration of enoxaparin use was 9 days, and the majority of patients (78%) received a prophylaxis dose of 40 mg subcutaneously (SC) once daily. The overall rate of VTE at 90 days was 1.4% while only 0.1% of patients developed major bleeding. There was no statistically significant difference in patients’ age, gender, BMI, or various enoxaparin dosing regimens between patients who developed VTE or bleeding versus patients who did not develop. Patient’s weight was the only statistically significant risk factor that directly correlated to higher risk of complications (P = 0.006). In the multivariable logistic regression model, higher BMI was significantly associated with treatment failure, either VTE or major bleeding [OR 1.05 (95% CI 1.0–1.09); P = 0.038]. ConclusionsThe rate of VTE or major bleeding did not differ in patients who received various enoxaparin regimens. Patients undergoing bariatric surgery may benefit from enoxaparin thromboprophylaxis dose of 40 mg SC daily for a total duration of 14 days, with higher doses may be needed for extremely obese patients. We recommend standardizing the current practice of VTE prophylaxis post bariatric surgery and unifying the optimal dose and duration.

Association of Changes in Antithrombin Activity Over Time With Responsiveness to Enoxaparin Prophylaxis and Risk of Trauma-Related Venous Thromboembolism

Venous thromboembolism (VTE) affects 2% to 20% of recovering trauma patients, despite aggressive prophylaxis with enoxaparin. Antithrombin is a primary circulating anticoagulant and crucial component of enoxaparin thromboprophylaxis. Approximately 20% of trauma patients present with antithrombin deficiency (antithrombin activity <80%). To examine time-dependent changes in antithrombin activity, responsiveness to enoxaparin, as measured by anti-factor Xa (anti-FXa) levels, and incidence of VTE after severe trauma and to assess the association of ex vivo antithrombin supplementation with patients' sensitivity to enoxaparin prophylaxis. This single-center, prospective cohort study was performed at a level 1 trauma center between January 7, 2019, and February 28, 2020. Adult trauma patients admitted to the trauma service at high risk for VTE, based on injury pattern and severity, were screened and enrolled. Patients who were older than 70 years, were pregnant, had a known immunologic or coagulation disorder, or were receiving prehospital anticoagulants were excluded. Blood samples were collected on emergency department arrival and daily for the first 8 days of hospitalization. Patients' antithrombin activity and anti-FXa levels were measured by a coagulation analyzer, and thrombin generation was measured by calibrated automated thrombography. Responsiveness to enoxaparin was assessed by measuring anti-FXa levels 4 to 6 hours after the first daily enoxaparin dose and compared between patients who developed VTE and who did not. In addition, the associations of ex vivo supplementation of antithrombin with plasma anti-FXa levels were assessed. Among 150 patients enrolled (median [IQR] age, 35 [27-53] years; 37 [24.7%] female and 113 [75.3%] male; 5 [3.3%] Asian, 32 [21.3%] Black, and 113 [75.3%] White; and 51 [34.0%] of Hispanic ethnicity), 28 (18.7%) developed VTE. Patients with VTE had significantly lower antithrombin activity on admission compared with patients without VTE (median [IQR], 91% [79%-104%] vs 100% [88%-112%]; P = .04), as well as lower antithrombin activity on hospital days 5 (median (IQR), 90% [83%-99%] vs 114% [99%-130%]; P = .011), 6 (median [IQR], 97% [81%-109%] vs 123% [104%-134%]; P = .003), 7 (median [IQR], 82% [74%-89%] vs 123% [110%-140%]; P < .001), and 8 (median [IQR], 99% [85%-100%] vs 123% [109%-146%]; P = .011). Anti-FXa levels were significantly lower in patients with VTE vs those without VTE at hospital day 4 (median [IQR], 0.10 [0.05-0.14] IU/mL vs 0.18 [0.13-0.23] IU/mL; P = .006), day 6 (median [IQR], 0.12 [0.08-0.14] IU/mL vs 0.22 [0.13-0.28] IU/mL; P = .02), and day 7 (median [IQR], 0.11 [0.08-0.12] IU/mL vs 0.21 [0.13, 0.28] IU/mL; P = .002). Multivariable analyses found that for every 10% decrease in antithrombin activity during the first 3 days, the risk of VTE increased 1.5-fold. The results of this cohort study suggest that after severe trauma, antithrombin deficiency is common and contributes to enoxaparin resistance and VTE. Interventional studies are necessary to determine the efficacy of antithrombin supplementation in the reduction of VTE incidence.

Anticoagulation as secondary prevention of massive lung thromboses in hospitalized patients with COVID-19

Anticoagulation as secondary prevention of massive lung thromboses in hospitalized patients with COVID-19

Assessment of Saudi Women's Adherence and Experience with Venous Thromboembolism Prophylaxis after Cesarean Section Delivery Using Telemedicine Technology.

Background Telemedicine technology is widely used especially after the COVID-19 pandemic. It can be used to give medical advice as well as follow up with the patients at home in the outpatient setting. Low molecular weight heparin, such as enoxaparin, decreases the risk of venous thromboembolism after cesarean delivery. Objective assessing postcesarean women's adherence and experience to enoxaparin thromboprophylaxis regimens in the outpatient setting via telephone calls. Methods prospective cohort study was conducted in the Maternity and Children Hospital (MCH). Postcesarean women were interviewed at the postnatal ward in the MCH. The participants were followed up for 10 days of the delivery to assess their adherence to and experience with enoxaparin thromboprophylaxis. Suboptimal adherence was defined as the missing of one or more doses of enoxaparin. Results 170 women participated in this study. The majority of them (78.8%) were fully adherent to enoxaparin while 21.2% missed at least one dose. The most-reported causes for suboptimal adherence were perceived lack of necessity (44.4%), forget to take the injection (30.6%), feeling of high load going to the primary care unit to take injection (27.8%), and fear of injection (11.1%). Conclusion Telemedicine technology could be used to assess patients' adherence. The study results showed that the majority of participants were fully adherent to postcesarean enoxaparin but more than 20% of the participants were suboptimal adherent. Proper patient education techniques could influence patients' adherence and potentially decrease the risk of DVT in those populations.

Enoxaparin for thromboprophylaxis in hospitalized COVID-19 patients: The X-COVID-19 Randomized Trial.

It is uncertain whether higher doses of anticoagulants than recommended for thromboprophylaxis are necessary in COVID-19 patients hospitalized in general wards METHODS: This is a multicentre, open-label, randomized trial performed in 9 Italian centres, comparing 40mg b.i.d. versus 40mg o.d. enoxaparin in COVID-19 patients, between April 30 2020 and April 25 2021. Primary efficacy outcome was in-hospital incidence of venous thromboembolism (VTE): asymptomatic or symptomatic proximal deep vein thrombosis (DVT) diagnosed by serial compression ultrasonography (CUS), and/or symptomatic pulmonary embolism (PE) diagnosed by computed tomography angiography (CTA). Secondary endpoints included each individual component of the primary efficacy outcome and a composite of death, VTE, mechanical ventilation, stroke, myocardial infarction, admission to ICU. Safety outcomes included major bleeding. The study was interrupted prematurely due to slow recruitment. We included 183 (96%) of the 189 enrolled patients in the primary analysis (91 in b.i.d., 92 in o.d.). Primary efficacy outcome occurred in 6 patients (6.5%, 0 DVT, 6 PE) in the o.d. group and 0 in the b.id. group (ARR 6.5, 95% CI: 1.5-11.6). The absence of concomitant DVT and imaging characteristics suggests that most pulmonary artery occlusions were actually caused by local thrombi rather than PE. Statistically nonsignificant differences in secondary and safety endpoints were observed, with two major bleeding events in each arm. No DVT developed in COVID-19 patients hospitalized in general wards, independently of enoxaparin dosing used for thromboprophylaxis. Pulmonary artery occlusions developed only in the o.d. group. Our trial is underpowered and with few events.

Risk factors for thromboembolic complications in patients with elevated body mass index during the perioperative period of laparoscopic myomectomy

Background. Uterine fibroid is one of the most common diseases in gynaecological practice accounting from 32 to 70 % according to various authors. In 80 % of cases, fibroids are observed in women of reproductive age. Laparoscopic myomectomy is one of the main methods of surgical treatment for uterine fibroids in women of reproductive age. A large number of advantages of this method of surgical treatment in many cases lead to underestimation of the existing risks such as the risk of thrombosis in women with elevated body mass index (BMI). The purpose of this study is to detect the risk of thrombosis in adequate comprehensive thromboprophylaxis of patients with elevated BMI in the perioperative period of laparoscopic myomectomy using an instrumental method of diagnosis such as low-frequency piezoelectric blood viscometer. Materials and methods. Patients aged 30–45 years undergoing laparoscopic myomectomy (n = 60) were examined. They were divided into 3 groups depending on the BMI and thromboprophylaxis method. Group 1 (n = 16) included women with the BMI &lt; 30 kg/m2, who did not receive thromboprophylaxis. Group 2 (n = 18) consisted of patients with the BMI &gt; 30 kg/m2, who were treated with enoxaparin thromboprophylaxis at a dose of 2,000 anti-Xa IU/0.2 ml subcutaneously (at the BMI of 30–40 kg/m2) and 4,000 anti-Xa IU/0.4 ml subcutaneously (at the BMI &gt; 40 kg/m2). Third group (n = 26) included individuals with the BMI &gt; 30 kg/m2 who received enoxaparin and pentoxifylline for thromboprophylaxis. Results. The low-frequency piezoelectric blood viscometry revealed statistically significant (p &lt; 0.05) deviations from the reference values of the coagulogram towards structural (increased maximum clot density) and chronometric hypercoagulation (acceleration of the time of formation of fibrin-platelet structure T5, shift of the blood clotting time T3 to the left, an increase in the intensity of coagulation drive), elevated thrombin activity (an increase in the constant of thrombin activity, a decrease in T2 time), activation of vascular-platelet hemostasis (reduced period of T1 reaction onset, increased intensity of contact coagulation), inhibition of the lytic activity (a decrease in the intensity of retraction and lysis of the clot) in groups 2 and 3. On the first day after surgery in groups 2 and 3, there was a significant increase (compared to preoperative indicators) in the chronometric indicators such as T1, T2 and T5; a decrease in the structural indicator of maximum clot density, as well as a significant decrease in the constant of thrombin activity, intensity of contact coagulation, which confirms the effectiveness of antithrombotic therapy. However, group 2 reported an increase in the activity of vascular-platelet hemostasis, higher intensity of contact coagulation compared to group 3, shorter T1 and T2 time, and the constant of thrombin activity was higher. On the 5th day after surgery, a normocoagulation trend of hemostatic potential was observed in all groups of patients. Conclusions. The use of low-frequency piezoelectric blood viscometry allows reliably and quickly assessing the kinetics of thrombosis formation.

Primary thromboprophylaxis to prevent thrombotic events in pediatric oncology patients with a malignant mediastinal mass.

Children with malignant mediastinal masses have increased thrombotic events (TE). Eligible subjects with malignant mediastinal masses between January 2000 and December 2017 were evaluated for TE, with 19 among 76 subjects receiving enoxaparin thromboprophylaxis. There were 13 TEs among 76 subjects for an incidence of 17.1%. Mediastinal compression directly led to TE in 9.2% of subjects who also had statistically significant superior vena cava compression at diagnosis. Primary thromboprophylaxis did not significantly affect TE occurrence; however, larger studies are warranted to consider strategic thromboprophylaxis guided by radiological monitoring of dynamic vascular compression to improve TE outcomes.

Application of thromboelastography in comparing coagulation difference of rivaroxaban and enoxaparin for thromboprophylaxis after total hip arthroplasty.

Purpose: The purpose of this study was to compare the coagulation difference in patients with either rivaroxaban or enoxaparin as thromboprophylaxis after total hip arthroplasty (THA) regarding thromboelastography (TEG) and routine coagulation tests. Patients and methods: Two hundred and twenty-eight patients undergoing primary THA were recruited in this study. They were divided into two groups according to a computer-generated random sequence. Patients in the rivaroxaban group received 10mg of rivaroxaban orally once daily. Patients in the enoxaparin group received 4000 AxaIU (0.4mL) of enoxaparin subcutaneously once daily. Rivaroxaban and enoxaparin were started 6-8h after surgery. The administration of the anticoagulant prophylaxis was lasted for a minimum of 14days. TEG and routine coagulation tests were performed on the day before the operation and 1day and 7days after the operation. Results: No difference was observed in the incidence of deep vein thrombosis (DVT) or pulmonary embolism (PE) between the two groups. There was no significant difference with regard to prothrombin time (PT), activated partial thromboplastin time (PTT), international normalized ratio (INR), and thrombin time (TT) between the two groups. However, while considering TEG, R time of the rivaroxaban group was significantly higher than that of the enoxaparin group (p = 0.003), whereas the maximum amplitude (MA) (p = 0.036) value and coagulation index (CI) (p = 0.002) value were significantly lower than those of the enoxaparin group. Conclusion: With regard to TEG analysis, there was coagulation difference in patients with rivaroxaban and those with enoxaparin as thromboprophylaxis after THA. Under recommended dose of rivaroxaban and enoxaparin, patients undergoing THA were in hypercoagulability on 7days postoperative.

Comparison of out-of-pocket cost between apixaban and enoxaparin for extended-duration venous thromboembolism prophylaxis in gynecologic oncology patients

<h3>Objectives:</h3> To compare out-of-pocket cost between apixaban and enoxaparin for prevention of postoperative venous thromboembolism (VTE) in gynecologic oncology patients. Current guidelines recommend low molecular weight heparin for thromboprophylaxis following gynecologic cancer surgery, but new evidence suggests that oral apixaban may provide another safe and effective alternative. Recent publications have suggested apixaban more cost-effective, however these data do not evaluate out-of-pocket cost. <h3>Methods:</h3> This retrospective study was approved by the institutional QIAB. Patients undergoing open surgery for gynecologic malignancy qualified for this study. Test claims for apixaban 2.5 mg by mouth twice daily and enoxaparin 40 mg subcutaneously daily for 28 days were submitted for each patient prior to surgery. Patient copays, number of patients requiring prior authorization, and number of patients without prescription insurance were collected. <h3>Results:</h3> A total of 86 consecutive patients had test claims sent for both apixaban and enoxaparin thromboprophylaxis between July 2020 and October 2020. The average patient out-of-pocket cost to complete 28 days of apixaban prophylaxis was $73.95 (median $42.84, range $0-448.45). The average patient cost to complete 28 days of enoxaparin prophylaxis was $38.08 (median $10, range $0-260.91). Partial fills were allowed for 4 of 5 enoxaparin prescriptions that required prior authorization. A total of 5 apixaban prescriptions (5.8%) required prior authorization for full 28 days. A total of 5 patients (5.8 %) did not have prescription insurance. Cash price for enoxaparin was nearly double the cash price of apixaban. A total 6 patients' (7 %) insurance was not contracted with our pharmacy. A single patient (1.2%) required enoxaparin via specialty pharmacy. A total of 2 patients (2.3 %) were enrolled in the institution's financial assistance per the institution. <h3>Conclusions:</h3> Patients prescribed extended-duration venous thromboembolism prophylaxis may face higher out-of-pocket costs with apixaban than with enoxaparin. Prior authorizations can often take 48 to 72 hours for approval. Sending test claims prior to surgery can help identify prescriptions that will need prior authorizations so prescriptions can be sent earlier to avoid discharge delays and patient nonadherence. There may not be a one size fits all solution and individualized patient care should be considered. Future research areas should evaluate patient adherence with a twice daily oral pill vs a once daily injection.

Safety of Venous Thromboprophylaxis With Low-molecular-weight Heparin in Children With Ulcerative Colitis.

To evaluate for increased rectal bleeding following enoxaparin thromboprophylaxis in children hospitalized for ulcerative colitis (UC). Retrospective cohort study (2007--2016) of 218 inpatients with active UC. Patients receiving enoxaparin were compared with a nonenoxaparin-treated patient group. Severity of UC was determined using the Pediatric Ulcerative Colitis Activity Index (PUCAI). Hemoglobin (Hb) values and packed red blood cell (pRBC) transfusions were reviewed for a 7-day period following hospital admission. A linear mixed effect model was used to compare change in Hb values between the groups. Risk of pRBC transfusion was compared using a log-rank test and Cox proportional hazard regression. A sub-analysis was also conducted restricting to patients with severe UC to provide more generalizable insight into safety profile of enoxaparin. Children hospitalized for UC and receiving enoxaparin were more likely to have severe disease, received infliximab therapy and be admitted after 2010. Use of enoxaparin showed there was not a difference (P = 0.60) in the fall of Hb detected among those with acute severe colitis (initial PUCAI ≥65) during the week following admission. Moreover, there was no difference in the risk of requiring a pRBC transfusion with enoxaparin use (log-rank test all patients: P = 0.80; severe UC: P = 0.88; Cox proportional hazard regression all patients: P = 0.72; severe UC: 0.85). There was no difference in Hb levels or need for blood transfusions in children hospitalized for severe UC (PUCAI ≥65) whether or not they received enoxaparin for thromboembolism prophylaxis.