Intracardiac ultrasound-guided transseptal puncture in horses: Outcome, follow-up, and perioperative anticoagulant treatment.

BACKGROUND: Cardiac catheterizations in horses are mainly performed in the right heart, as access to the left heart traditionally requires an arterial approach. Transseptal puncture (TSP) has been adapted for horses but data on follow-up and closure of the iatrogenic atrial septal defect (iASD) are lacking. HYPOTHESIS/OBJECTIVES: To perform TSP and assess postoperative complications and iASD closure over a minimum of 4 weeks. ANIMALS: Eleven healthy adult horses. METHODS: Transseptal puncture was performed under general anesthesia. Serum cardiac troponin I concentrations were measured before and after puncture. Weekly, iASD closure was monitored using transthoracic and intracardiac echocardiography. Relationship between activated clotting time and anti-factor Xa activity during postoperative enoxaparin treatment was assessed in vitro and in vivo. RESULTS: Transseptal puncture was successfully achieved in all horses within a median duration of 22 (range, 10-104) minutes. Balloon dilatation of the puncture site for sheath advancement was needed in 4 horses. Atrial arrhythmias occurred in 9/11 horses, including atrial premature depolarizations (N = 1), atrial tachycardia (N = 5), and fibrillation (N = 3). Serum cardiac troponin I concentrations increased after TSP, but remained under the reference value in 10/11 horses. Median time to iASD closure was 14 (1-35) days. Activated clotting time correlated with anti-factor Xa activity in vitro but not in vivo. CONCLUSIONS AND CLINICAL IMPORTANCE: Transseptal puncture was successfully performed in all horses. The technique was safe and spontaneous iASD closure occurred in all horses. Clinical application of TSP will allow characterization and treatment of left-sided arrhythmias in horses.

Therapeutic Enoxaparin Dosing in Obesity.

OBJECTIVE: This review aims to systematically summarize the available data on efficacy and safety of therapeutic enoxaparin in obese patients and to identify gaps to guide future research. DATA SOURCES: Medline and Embase were systematically searched for eligible studies (last searched December 20, 2023). Studies were included if they reported on therapeutic dosing regimens, adverse bleeding, thrombotic outcomes, or antifactor Xa (AFXa) monitoring in obese adult patients. STUDY SELECTION AND DATA EXTRACTION: The systematic review management tool Covidence was used to manage the study selection and data extraction process. The reference list from eligible studies was screened to determine any additional eligible studies. DATA SYNTHESIS: Sixteen studies were included in the analysis. Studies used a variety of doses, indications, and study designs making comparison difficult. Twelve studies reported the incidence of thrombotic events (median = 1.3% [interquartile range [IQR] = 0.3%-2.3%]) and all studies reported the incidence of bleeding events (median = 5.7% [IQR = 2.4%-14.5%]). Two of the 8 studies analyzing the influence of weight/body mass index (BMI) or dose per kg on AFXa levels reported statistically significant results. One study concluded that BMI did not affect achievement of target AFXa levels. However, the second study found that dosing using actual body weight was an independent predictor of supratherapeutic AFXa levels in the obese population. RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE: This is the first comprehensive review with a focus on therapeutic dosing of enoxaparin in obesity and has been conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 statement. Seven of the included studies were published since 2018 indicating that new evidence on this topic is emerging. CONCLUSION: There was inadequate evidence to support an optimal dosing strategy in obese patients due to the heterogeneity of the studies. The AFXa monitoring may be appropriate to guide dosing in this population. Further research is required to determine a suitable dosing regimen.

Venous Thromboembolism Rates in Trauma Patients Significantly Increase With Missed Prophylactic Enoxaparin Doses.

Background: Current literature demonstrates prophylactic enoxaparin to be efficacious in reducing venous thromboembolism (VTE) rates without significantly increasing risk for bleeding complications. Despite this evidence, prophylactic enoxaparin doses are frequently withheld for surgery or procedures. This exploratory study aims to quantify the risk of a VTE event in trauma patients associated with missed doses of prophylactic enoxaparin. Methods: This retrospective cohort study evaluated trauma patients admitted to our Level 1 trauma center from January 1, 2012 to January 31, 2021. A 1:1 propensity match with ten variables was performed to compare patients receiving prophylactic enoxaparin that had a VTE and those that did not. The primary outcome was a VTE event. Results: 493 patients met inclusion criteria; 1:1 propensity score matching was performed resulting in a cohort of 184 patients. The percentage of patients that missed a prophylactic enoxaparin dose in the VTE group was higher than the no VTE group (34.8% vs 21.7%, P = 0.049). This is consistent when examining total missed doses (P = 0.038) and consecutively missed doses (P = 0.035). The odds of having a VTE for patients that missed at least one dose or more of enoxaparin are nearly two times greater (OR 1.92, 95% CI 0.997, 3.7). Conclusion: Missing enoxaparin doses significantly increases the risk of VTE in matched populations. Most prophylactic enoxaparin doses were held for procedures, and not for bleeding events. Trauma teams should carefully weigh the risk of bleeding complications associated with continuing enoxaparin prophylaxis against the significant thromboembolic risk of withholding it.

Anti-Xa activity below range is related to thrombosis in patients with severe COVID-19.

OBJECTIVE: We aimed to anlayse the relationship between anti-Xa activity below range and thomboembolic events. DESIGN: Single center prospective observational longitudinal cohort study (February-November 2021). SETTING: Patients admitted to the ICU of a University Hospital. PARTICIPANTS: Patients with severe COVID-19 pneumoniae. INTERVENTIONS: Enoxaparin was used for prophylactic and therapeutic anticoagulation. Enoxaparin dosing and dose adjustment were based on anti-Xa activity according to the hospital protocol. MAIN VARIABLES OF INTEREST: Target: thomboembolic events. PREDICTORS: demographics, pharmacotherapy, anti-Xa measurements, clinical data, and laboratory results. Logistic regression was used to identify independent risk factors for thomboembolic events. RESULTS: Data were available for 896 serum anti-Xa measurements from 228 subjects. Overall, 71.9% were male, with a median age of 62. Most patients needed invasive mechanical ventilation (87.7%) and mortality was 24.1%. A total of 28.9% new thomboembolic events were diagnosed. There were 27.1% anti-Xa measesurements below range. When multivariable logistic regression analysis was performed anti-Xa activity below range (RR, 4.2; p = 0.000), C-reactive protein (25 mg/L increase) (RR, 1.14; p = 0.005) and D-dimer (1000 ng/L increase) (RR, 1.06; p = 0.002) were the independent factors related to new thomboembolic events in patients with severe COVID-19. CONCLUSIONS: Anti-Xa activity below range, C-reactive protein and D-dimer were the independent factors related to thomboembolic events in patients with severe COVID-19. Purposely designed clinical trials should be carried out to confirm the benefit of an anti-Xa monitoring.

How enoxaparin underdosing and sex contribute to achieving therapeutic anti-Xa levels.

Introduction: Anti-Xa serves as a clinical surrogate for assessing the efficacy and bleeding risk in patients treated with enoxaparin for thromboembolic events. Evidence from the literature and empirical observations suggest that patients are underdosed in clinical practice to avoid bleeding complications. This study aimed to investigate such underdosing of enoxaparin and its potential impact on achieving therapeutic anti-Xa levels. Methods: This multicentric, retrospective, observational study included patients with acute ischemic stroke due to atrial fibrillation. All patients received enoxaparin in the therapeutic setting with subsequent anti-Xa measurements. The one-sample, one-tailed Wilcoxon signed-rank test was used to identify a significant difference between the doses administered and the recommended daily dose. Logistic regression model analysis was performed to identify additional predictors affecting achievement of the therapeutic anti-Xa target range. Stepwise forward-backward selection with Akaike's information criterion as metric was applied to refine the logistic regression model. Results: A total of 145 patients from the university hospitals of St. Pölten and Tulln in Lower Austria were included. The median daily enoxaparin dose administered was 1.23 mg/kg, resulting in an overall target range achievement rate of 66%. As compared to recommended therapeutic doses, significant underdosing of enoxaparin was evident in both participating centers (p < 0.001). The calculated threshold dose to achieve the therapeutic target range with a 90% probability was 1.5 mg/kg enoxaparin daily. Female sex was found to be a strong independent predictor of achieving a therapeutic target range (OR 9.44; 95% CI 3.40-30.05, p < 0.001). Conclusion: Despite the underdosing observed in both centers, therapeutic anti-Xa levels were achieved with lower than recommended doses of enoxaparin, and women required even lower doses than men. These findings warrant further confirmation by prospective studies.

A child with sickle cell disease admitted with coronavirus disease 2019 pneumonia and acute chest syndrome in pediatric intensive care unit: A case report.

Management of sickle cell disease complications in the setting of the coronavirus disease 2019 (COVID-19) pandemic is complicated with little published pediatric data. We report the first documented case of a 9-year-old boy with sickle cell disease, presenting with fever, cough, and shortness of breath, diagnosed to have acute chest syndrome and coronavirus disease 2019 (COVID-19) pneumonia with inflammatory storm requiring ventilation, exchange blood transfusion, immunomodulatory agents, and prophylactic anticoagulation. The patient responded satisfactorily to the management of the acute illness and was found to be well at the next visit to the pediatric hematology outpatient department following hospital discharge.

Investigation of the effects of treatment with enoxaparin sodium and hyperbaric oxygen therapy on the recovery of rats with achilles tendon rupture.

PURPOSE: In this study, we aimed to investigate the effects of hyperbaric oxygen therapy and enoxaparin sodium, which are known to accelerate bone tissue healing as well as tendon and soft tissue healing, on the healing of Achilles tendon rupture. METHODS: Thirty-six rats were used in the present study. All rats were divided into groups of nine. The groups were the enoxaparin sodium group, enoxaparin sodium and hyperbaric oxygen group, hyperbaric oxygen group and control group. After 21 days, the process was completed, and the rats were sacrificed. Achilles tendon samples were evaluated histopathologically. RESULTS: The groups were compared according to the results of statistical analysis based on the histopathological data. There was no significant difference between the groups in terms of acute inflammation (p = 0.785) or chronic inflammation (p = 0.827) scores, but there were significant differences in neovascularization (p = 0.009), proliferation (p < 0.001) and fibrosis (p = 0.006) scores. CONCLUSION: Our study showed that the use of enoxaparin sodium and hyperbaric oxygen had a positive effect on the healing of the Achilles tendon. Based on these results, we believe that the use of enoxaparin sodium and hyperbaric oxygen therapy after Achilles tendon rupture will be beneficial for healing and preventing complications.

Anti factor Xa monitoring for venous thromboprophylaxis in severely burn-injured patients: A systematic review.

INTRODUCTION: Patients with severe burn injuries are at risk of venous thromboembolism (VTE) and associated sequelae. Burn-injured patients may require larger doses of VTE prophylaxis so underdosing may occur with standard regimens. Monitoring anti-factor Xa (AFXa) levels may allow tailoring of dosage but is currently uncommon. The purpose of this systematic review was to methodically review the available literature with respect to AFXa in severe burn-injured patients, and thereby assess its efficacy. METHODS: Using PRISMA guidelines, "Xa" and "burns" were used to systematically review MEDLINE (1946 - present) and EMBASE (1974 - present) databases for publications regarding the monitoring of AFXa levels for thromboprophylaxis in burn-injured patients. RESULTS: Eight studies (432 patients) met inclusion. Peak AFXa level at initial measurement was reported in all studies and was within the range for prophylaxis in 184 of 432 cases (42.6%), below range in 246 of 432 cases (56.9%) and above range for 2/432 (0.5%). Complications were reported in 7 studies (412 patients), with a total of 30 (7.3%) complications, comprising of 16 (53.3%) VTE events and 14 (46.7%) mortalities. Three studies comprising 270 patients compared complications between patients who were within the reference range with patients who were below the range. There were 164 patients from the 'within the reference range' groups that had a total of 6 (3.7%) complications, comprised of 4 (66.7%) VTE events and 2 (33.3%) mortalities. There were 106 patients from the 'below reference range group' that had a total of 11 (10.4%) complications, comprised of 9 (81.8%) VTE events and 2 (18.2%) mortalities. CONCLUSION: Our findings suggest standard prophylactic anticoagulation dosing risks underdosing and therefore, an increased risk in the development of VTE. AFXa monitoring allows individually tailored dose adjustment to reach therapeutic levels, which may be efficacious in reducing VTE events and is therefore recommended where possible.

A Case of Deep Venous Thrombosis in an HIV-Infected Patient despite Therapeutic Anticoagulation.

Patients with human immunodeficiency virus (HIV) infection have an increased likelihood of venous thromboembolism (VTE) owing to factors such as acquired protein C and S deficiency, antiphospholipid antibody syndrome, and heightened levels of pro-inflammatory cytokines. This case report highlights an exceptionally uncommon occurrence of deep venous thrombosis in an HIV-infected patient receiving a therapeutic dose of enoxaparin. This underscores the need for cautious consideration of the risk of VTE in HIV-infected individuals, even with preventive or therapeutic anticoagulant treatment. Further research is recommended to investigate HIV as a potential risk factor of prophylactic anticoagulation.

Efficacy and Safety of Rivaroxaban Versus Enoxaparin in Prevention of Recurrence of Venous Thrombo-Embolism Events in Cancer Patients: A Meta-Analysis.

OBJECTIVE: To examine the effectiveness of rivaroxaban compared to enoxaparin in patients diagnosed with cancer and venous thromboembolism. METHODS: A search of Pub Med, Scopus, and Google Scholar, from inception through April 2023 was conducted. Articles comparing rivaroxaban with enoxaparin in patients with cancer and VTE/PE/DVT were included. Review Manager Version 5.2 was utilised for the analysis of the following outcomes; VTE, PE, DVT, major bleeding, and mortality. RESULTS: A total of 8 articles and 2276 patients were included in the final analysis. Pooled analysis showed that rivaroxaban had a statistically insignificant reduced association with VTE occurrence (RR:0.83, 95% CI:0.58-1.18, P:0.3) as well as a statically insignificant reduction in major bleeding (RR:0.79, 95% CI:0.53-1.18, P:0.25). Analysis showcased that there was an insignificant reduction of mortality rivaroxaban as compared to enoxaparin (RR:0.74, 95% CI: 0.46-1.20, P:0.23). CONCLUSION: Rivaroxaban can serve as a viable alternative to enoxaparin, with no appreciable drawbacks, for preventing and managing VTE in patients with malignancy.

A Comparison between Enoxaparin and Aspirin in Preventing Deep Vein Thrombosis after Spine Surgery: A Randomized Clinical Trial.

Objectives: Deep Vein Thrombosis (DVT) is a significant medical concern characterized by the formation of blood clots within the venous system. Surgical procedures are known to increase the risk of DVT. While enoxaparin has proven to be highly effective in treating DVT, concerns about bleeding and accurate dosage regulation may restrict its application. Recent research has focused on aspirin's potential in preventing DVT after various surgeries. This study aimed to determine whether aspirin was as effective as enoxaparin in preventing DVT after spine surgery. Methods: This randomized controlled trial enrolled study patients who underwent spine surgery at Shahid Kamyab Emergency Hospital in Mashhad, and had a Caprini score > 5, indicating a higher risk of DVT. In the control group, patients received subcutaneous injections of enoxaparin at a dosage of 40 mg, while the intervention group received oral aspirin tablets with a daily dosage of 81 mg. An experienced radiologist performed a Doppler ultrasound of the lower limbs' veins seven days after surgery to diagnose DVT. The outcomes of the two groups were then compared. Results: A total of 100 patients participated in the clinical trial and were equally assigned to the aspirin and enoxaparin groups. Both groups were homogeneous regarding the basic and clinical characteristics. The incidence of postoperative DVT was 4.0% in the aspirin group and 10.0% in the enoxaparin group (p=0.092). The incidence of hemorrhage was 2.0% in the aspirin group and 4.0% in the enoxaparin group (p=0.610). Conclusion: These findings indicate that aspirin may be a promising alternative to enoxaparin for DVT prevention after surgery, but additional research is essential to validate these results and further assess the benefits and risks associated with aspirin usage in this context.

Complications of Infective Endocarditis: A Case Report of Intracerebral Hemorrhage Exacerbated by Enoxaparin.

Infective endocarditis (IE) can cause life-threatening intracerebral hemorrhage via the transformation of an embolic ischemic stroke. Navigating anticoagulant therapy for IE patients is challenging due to this risk. Hospitalized patients often receive anticoagulation to minimize venous thromboembolism (VTE). Those at higher VTE risk may require full anticoagulation, particularly if there is an initial suspicion of a blood clot. A timely IE diagnosis is crucial but is often delayed during inpatient stays, with the patient potentially already on anticoagulants for other conditions. Our case discusses a hemorrhagic stroke in a patient with IE while receiving therapeutic enoxaparin. Clinical signs and symptoms, echocardiographic findings, laboratory workup and microbiological data, and possibly other imaging techniques such as cerebral magnetic resonance imaging (MRI) need to be employed in a timely manner in determining endocarditis as a cause of stroke.

Enoxaparin Effect on Interleukin-10 Levels in Iraqi Patients with COVID-19: A Case-Control Study.

BACKGROUND: Coronavirus disease 19 (COVID-19), an infectious disease resulting from a virus known as severe acute respiratory syndrome coronavirus 2 (SARS-COV-2), was discovered in China in 2019 and causes several mild to moderate respiratory conditions. This study aimed to reveal the changes in serum interleukin-10 (IL-10) and other parameters in Iraqi COVID-19 patients compared with healthy controls by studying the effects of enoxaparin and evaluating the potential of IL-10 as a disease activity marker. METHODS: This was a case-control study that included 180 samples: 90 patients hospitalized with COVID-19 from November 2022 to 20 April 2023 (40 patients had never used enoxaparin, whereas 50 patients had taken enoxaparin) and 90 healthy, age- and sex-matched control. There were 44 female patients and 46 male patients. The mean age of the patients and controls was 53.8 years vs. 50.8 years, respectively. The sandwich enzyme-linked immunosorbent assay (ELISA) method was used to measure IL-10 levels, while other parameters were assessed using the colorimetric method. RESULTS: The results of the study indicated highly significant changes between the patients and healthy controls in IL-10, D-dimer, and C-reactive protein (CRP) levels, as well as liver and renal functions. These findings elucidated a significant change between enoxaparin patients and non-enoxaparin patients in IL-10, D-dimer, and CRP levels. However, the liver and renal functions were not significantly altered. The Spearman's rank correlation test investigated the relationship between serum IL-10 and CRP. CONCLUSIONS: The results displayed a strong positive relationship between IL-10 and CRP. There were no significant differences between the other analyzed parameters; consequently, the patients had higher concentrations of IL-10, D-dimer, and some other parameters than the healthy controls. Additionally, IL-10 may be used as a marker of disease activity. Enoxaparin will likely help control IL-10 and D-dimer concentrations in patients since IL-10 levels decreased in patients treated with enoxaparin.

The effects of enoxaparin treatment in a xenograft mouse model of oral squamous cell carcinoma: A pilot study.

BACKGROUND: Recent studies suggest that enoxaparin may have therapeutic effects on oral squamous cell carcinoma. We aimed to assess this effect utilizing xenograft mouse model through evaluations of proliferation and angiogenesis markers at the RNA and protein levels. METHODS: Mice were divided into enoxaparin treatment (n = 4), positive control (n = 4) and negative control (n = 3) groups. Immunohistochemical analyses were performed utilizing Bcl-2, Bax and Ki-67 antibodies. Expression levels of proliferation and apoptosis related genes were calculated utilizing qRT-PCR. Time-dependent proliferation assays were performed in OSC-19 and HEK293 cell-lines. RESULTS: Bax antibody showed positive staining in the cytoplasm and nuclei of tumor cells, while Bcl-2 antibody displayed staining only in the cytoplasm. A proliferation index of 15%-20% was found in all groups with the Ki-67 marker indicating no metastasis. Enoxaparin treatment caused decrease in BCL2, BAX and CCNB1 genes' expressions. Compared to HEK293, proliferation assays demonstrated higher division rates in OSC-19 with a significant decrease in viability after 96 h. CONCLUSION: Reduced BCL-2 expression indicates a regression of tumor growth, but reduced BAX expression is not correlated with increased apoptosis. Despite the aggressive nature of OSC-19, our results showed a low cell viability with a high division rate when compared with the control HEK293. This paralleled our in vivo findings that showed absence of lymph node metastasis across all mice groups. This discrepancy with the literature suggests that further investigations of the underlying mechanisms and protein-level analyses are needed to draw definitive conclusions about the effect of enoxaparin on OSC-19 behavior.

Enoxaparin sodium combined with magnesium sulfate in the treatment of severe preeclampsia.

Objective: To observe the treatment of severe preeclampsia in newborns with enoxaparin sodium combined with magnesium sulfate. Methods: A retrospective analysis was conducted on the clinical data of 80 patients with severe preeclampsia admitted to Hefei Second People's Hospital, China from January 2019 to December 2020. Treatment records showed that 40 cases received magnesium sulfate treatment (single group), and 40 cases received enoxaparin sodium combined with magnesium sulfate treatment (combination group). Levels of D-dimer, soluble fms-like tyrosine kinase 1 (sFlt-1), placental growth factor (PLGF), Apgar scores of newborns delivered before and after treatment were compared. Gestation weeks and incidence of adverse reactions were analyzed. Results: After treatment, levels of D-dimer, sfit-1 and adverse reactions in the combination group were significantly lower than those in the single group (P<0.05), and the level of PLGF, newborn Apgar score and length of gestation were significantly higher than those in the single group (P<0.05). Conclusion: Compared to magnesium sulfate alone, the combination of enoxaparin sodium and magnesium sulfate in the treatment of pregnant women with severe preeclampsia can more effectively regulate the cytokine level of patients, improve pregnancy outcome, and improve neonatal Apgar score. The incidence of adverse reactions is low, making it a safe and efficient treatment modality.

Effect of Enoxaparin on D-dimer levels in hospitalized Corona Virus patients with a comparison of its level in patients with comorbid conditions.

OBJECTIVE: Aim: The main goal is to assess the levels of comorbid diseases and examine the changes in D-dimer in hospitalized patients before and following SC enoxaparin medication. PATIENTS AND METHODS: Material and Methods: At the Al-Yarmouk Teaching Hospital in Baghdad, Iraq, from October 2022 to May 2023, 86 patients who were hospitalized and had severe to critical COVID-19 infections provided data for a retrospective analysis. RESULTS: Results: The medical records of all COVID-19 patients who were hospitalized and whose D-dimer level was greater than 0.5 mg/l and who were given enoxaparin (40 mg subcutaneously) were reviewed with the requisite authorization from the relevant authorities. The D-dimer level was assessed following therapy on the day of admission and day five after commencing enoxaparin. An examination of 86 case records revealed that persons with COVID-19 had significantly decreased D-dimer levels after taking subcutaneous enoxaparin (p-value<0.0001). The comorbidities (diabetes mellitus, hypertension) of patients who received the drug were compared. CONCLUSION: Conclusions: Enoxaparin and other anticoagulants were utilized to treat the coagulopathy brought on by COVID-19. Low molecular weight heparin enoxaparin has demonstrated positive outcomes in the management of VTE. A decrease in D-dimer level is anticipated when COVID-19 patients are treated with subcutaneous enoxaparin, partly because decreased coagulation results in lower fibrin formation.

Distinct antithrombin activation modes for fondaparinux and natural heparins detected using millisecond hydrogen deuterium exchange and collision induced unfolding.

Low molecular weight heparin and synthetic mimetics such as fondaparinux show different binding kinetics, protease specificity, and clinical effects. A combination of allosteric and template-mediated bridging mechanisms have been proposed to explain the differences in rate acceleration and specificity. The difficulty in working with heterogeneous heparin species has rendered a crystallographic interpretation of the differences in antithrombin activation between mimetics and natural heparin inaccessible. In this study, we examine the allosteric changes in antithrombin caused by binding fondaparinux, enoxaparin and depolymerized natural heparins using millisecond hydrogen deuterium exchange mass spectrometry (TRESI-HDX MS) and relate these conformational changes to complex stability in the gas phase using collision induced unfolding (CIU). This exploration reveals that in addition to the dynamic changes caused by fondaparinux, long chain heparins reduce structural flexibility proximal to Arg393, the cleavable residue in the reactive centre loop of the protein. These local changes in protein dynamics are associated with an increase in overall complex stability that increases with heparin chain length. Ultimately, these results shed light on the molecular mechanisms underlying differences in activity and specificity between heparin mimetics and natural heparins.

Pharmacologic Venous Thromboembolism Prophylaxis in Patients with Nontraumatic Subarachnoid Hemorrhage Requiring an External Ventricular Drain.

BACKGROUND: Optimal pharmacologic thromboprophylaxis dosing is not well described in patients with subarachnoid hemorrhage (SAH) with an external ventricular drain (EVD). Our patients with SAH with an EVD who receive prophylactic enoxaparin are routinely monitored using timed anti-Xa levels. Our primary study goal was to determine the frequency of venous thromboembolism (VTE) and secondary intracranial hemorrhage (ICH) for this population of patients who received pharmacologic prophylaxis with enoxaparin or unfractionated heparin (UFH). METHODS: A retrospective chart review was performed for all patients with SAH admitted to the neurocritical care unit at Emory University Hospital between 2012 and 2017. All patients with SAH who required an EVD were included. RESULTS: Of 1,351 patients screened, 868 required an EVD. Of these 868 patients, 627 received enoxaparin, 114 received UFH, and 127 did not receive pharmacologic prophylaxis. VTE occurred in 7.5% of patients in the enoxaparin group, 4.4% in the UFH group (p = 0.32), and 3.2% in the no VTE prophylaxis group (p = 0.08). Secondary ICH occurred in 3.83% of patients in the enoxaparin group, 3.51% in the UFH group (p = 1), and 3.94% in the no VTE prophylaxis group (p = 0.53). As steady-state anti-Xa levels increased from 0.1 units/mL to > 0.3 units/mL, there was a trend toward a lower incidence of VTE. However, no correlation was noted between rising anti-Xa levels and an increased incidence of secondary ICH. When compared, neither enoxaparin nor UFH use was associated with a significantly reduced incidence of VTE or an increased incidence of ICH. CONCLUSIONS: In this retrospective study of patients with nontraumatic SAH with an EVD who received enoxaparin or UFH VTE prophylaxis or no VTE prophylaxis, there was no statistically significant difference in the incidence of VTE or secondary ICH. For patients receiving prophylactic enoxaparin, achieving higher steady-state target anti-Xa levels may be associated with a lower incidence of VTE without increasing the risk of secondary ICH.

The influence of perioperative enoxaparin on bleeding after TORS oropharyngectomy.

Perioperative enoxaparin is often avoided in patients undergoing transoral robotic (TORS) oropharyngectomy. Our goal was to quantify the risk of postoperative hemorrhage (POH) in patients receiving enoxaparin after TORS oropharyngectomy. This was a retrospective database cohort study set up in 89 separate healthcare organizations. The TriNetX electronic database was queried for patients with OPSCC who underwent TORS oropharyngectomy. Propensity-score matching was used to create two cohorts, one receiving and one not receiving perioperative enoxaparin. Outcome measures were the POH rate within 1 day of surgery ("primary") and POH rate within 2-30 days of surgery ("secondary"). 1109 patients undergoing TORS for OPSCC were identified, 400 of which received perioperative enoxaparin. One-to-one propensity score matching resulted in 310 patients per cohort. After matching, the primary POH rates between patients receiving and not receiving enoxaparin were 3.23% for both cohorts (OR 1.000, 95% CI 0.410 to 2.438). The secondary POH rates between those receiving and not receiving enoxaparin were 5.47% vs. 3.54% (OR 1.577, 95% CI 0.726 to 3.424). The number needed to harm (NNH) with perioperative enoxaparin use for secondary POH after TORS was 53; no difference was found in primary POH rates. While not statistically significant, the use of perioperative enoxaparin after TORS is associated with increased odds of secondary POH with a NNH of 53; no difference was found in rates of primary POH. For patients undergoing TORS, enoxaparin use requires careful weighing of the risks and benefits.

Interaction of heparin with human cardiac troponin complex and its influence on the immunodetection of troponins in human blood samples.

OBJECTIVES: Heparin is a highly charged polysaccharide used as an anticoagulant to prevent blood coagulation in patients with presumed myocardial infarction and to prepare heparin plasma samples for laboratory tests. There are conflicting data regarding the effects of heparin on the measurement of cardiac isoforms of troponin I (cTnI) and troponin T (cTnT), which are used for the immunodiagnosis of acute myocardial infarction. In this study, we investigated the influence of heparin on the immunodetection of human cardiac troponins. METHODS: Gel filtration (GF) techniques and sandwich fluoroimmunoassay were performed. The regions of сTnI and cTnT that are affected by heparin were investigated with a panel of anti-cTnI and anti-cTnT monoclonal antibodies, specific to different epitopes. RESULTS: Heparin was shown to bind to the human cardiac full-size ternary troponin complex (ITC-complex) and free cTnT, which increased their apparent molecular weights in GF studies. Heparin did not bind to the low molecular weight ITC-complex and to binary cTnI-troponin С complex. We did not detect any sites on cTnI in the ITC-complex that were specifically affected by heparin. In contrast, cTnT regions limited to approximately 69-99, 119-138 and 145-164 amino acid residues (aar) in the ITC-complex and a region that lies approximately between 236 and 255 aar of free cTnT were prone to heparin influence. CONCLUSIONS: Heparin binds to the ITC-complex via cTnT, interacting with several sites on the N-terminal and/or central parts of the cTnT molecule, which might influence the immunodetection of analytes in human blood.