Dose Of Enoxaparin Research Articles

Anti-Factor Xa Monitoring of Enoxaparin Thromboembolism Prophylaxis in Emergency General Surgery Patients.

Rates of venous thromboembolism (VTE) remain high in emergency general surgery (EGS) patients despite chemical VTE prophylaxis. Emerging literature supports anti-factor Xa (AFXa) monitoring for patients on enoxaparin (LMWH), although a significant knowledge gap remains regarding the optimal dosing and monitoring in EGS patients. We hypothesize that standard dose VTE prophylaxis regimens provide inadequate VTE prophylaxis in EGS patients. A prospective cohort study of all adult EGS patients at a single institution between August 2021 and February 2022 receiving standard dose LMWH for VTE prophylaxis was performed. AFXa levels were obtained 4 hours after the third dose of enoxaparin with a target range of 0.3 to 0.5 IU/mL. Adjustment to dosing and repeat AFXa measurement after the adjusted third dose was obtained. A total of 81 patients underwent AFXa monitoring, the majority (75%) of whom were started on 40 mg LMWH daily. Initial peak AFXa measurement was low in 87.7% of patients (mean 0.16 IU/mL). Of patients who had an initial low AFXa, remained admitted, and underwent dosing adjustment and AFXa reassessment (27%), the majority were adjusted to either 30 or 40 mg of LMWH twice daily (23.7% and 55%, respectively), with 82% of patients remaining low. There were no significant differences in demographics or BMI between those with low vs adequate AFXa levels at either initial or subsequent measurement. Standard LMWH dosing provides inadequate AFXa inhibition for adequate VTE prophylaxis. These findings highlight the importance of ongoing AFXa monitoring and the need to establish clinical protocols to improve VTE prophylaxis in EGS patients.

British Society for Haematology guideline for anticoagulantmanagement of pregnant individuals with mechanical heart valves.

British Society for Haematology guideline for anticoagulantmanagement of pregnant individuals with mechanical heart valves.

Creatinine Clearance May Predict Goal Enoxaparin Dose in Trauma.

Guidelines for enoxaparin dosing after trauma recommend an initial dose of 40 mg twice daily for most patients and then adjusting by anti-Xa levels. Previous studies indicated higher enoxaparin doses are necessary with higher levels of creatinine clearance (CrCl). We sought to determine if the goal enoxaparin dose correlates with the admission CrCl to reduce the reliance on measuring anti-Xa levels. A retrospective review was conducted of patients admitted to an urban, academic Level 1 trauma center from April 2017 to February 2020. Patients started on enoxaparin who reached goal anti-Xa trough levels were included, and patients were excluded if they did not reach goal anti-Xa levels. Data collection included patient demographics, injury characteristics, admission CrCl, and final enoxaparin dose. CrCl was then correlated with the final enoxaparin dose. Of 421 patients included, the mean age was 46.6 years and 73% were male. The median goal enoxaparin dose was 40 mg twice daily. The mean CrCl significantly increased with increasing twice-daily doses of enoxaparin (20 mg: 69.2 mL/min; 30 mg: 89 mL/min; 40 mg: 112.8 mL/min; 50 mg: 140.5mL/min; 60 mg: 147.4 mL/min; and 70 mg: 140 mL/min; p < 0.01). Admission CrCl may predict the enoxaparin dose required to achieve adequate anti-Xa levels. Our data indicate that CrCls of approximately 70, 90, 110, 140, and 150 mL/min may predict the twice-daily enoxaparin doses of 20, 30, 40, 50, and 60 mg, respectively. CrCl dosing guidance may reduce the time to goal anti-Xa levels and the frequency of anti-Xa measurements. Further research is necessary, and enoxaparin dosing should continue to be monitored by anti-Xa levels.

Effectiveness of Body Mass Index–Based Prophylactic Enoxaparin Dosing in Bariatric Surgery Patients

IntroductionEnoxaparin is administered for venous thromboembolic (VTE) prophylaxis in bariatric surgery patients. There is concern whether body mass index (BMI)-based enoxaparin dosing consistently achieves prophylactic targets in patients with severe obesity. MethodsThis retrospective study included patients who underwent bariatric surgery at an academic medical center from Jan 2015-May 2021 and had an anti-Xa level drawn 2.5-6 h after ≥3 doses of BMI-based prophylactic enoxaparin. The primary outcome was the percentage of patients who achieved a target anti-Xa level. Secondary outcomes were prevalence of venous thromboembolic and bleeding events within 30 d post-operatively. ResultsOverall, 137 patients were included. Mean BMI was 59.1 ± 10.4 kg/m2, mean age was 43.9 ± 13.3 y and 110 patients (80.3%) were female. Target anti-Xa levels were achieved in 116 patients (84.7%); 14 (10.2%) were above target and 7 (5.1%) were below target. Patients with above target anti-Xa levels were significantly shorter in height than those within target range (167.1 versus 159.8 cm, P = 0.003). Five patients (3.6%) had a bleeding event; no thromboembolisms occurred. Anti-Xa levels correlated more strongly with enoxaparin dose per unit estimated blood volume (EBV) than dose per unit BMI (Rho = 0.54 versus Rho = 0.33). ConclusionsTarget range anti-Xa levels were achieved in 85% of patients using BMI-based enoxaparin dosing. Patients with above target anti-Xa levels were significantly shorter by nearly 3 inches, suggesting an increased risk of overdosing enoxaparin in shorter, obese patients. An EBV-based dosing regimen may better account for patient height and is supported by a greater correlation with anti-Xa levels with dosing based on EBV than BMI.

Transient Right Bundle Branch Block with S1Q3T3 Pattern in Pulmonary Embolism

A 69-year-old woman with hypertension, hyperlipidemia, sleep apnea, gastroesophageal reflux disease, and recent knee replacement was brought to the emergency room (ER) for syncope. She had her physiotherapy session earlier in the day and became symptomatic with dizziness, shortness of breath and had loss of consciousness. In the ER, systolic blood pressure (SBP) was noted to be 90 mmHg and an oxygen saturation (O2 sat) of 80% on room air. Patient received fluid bolus with improvement of SBP to 110 mmHg. O2 sat improved to 99% with 10 L of oxygen. A bedside echocardiogram showed right ventricular (RV) distension. A Computerized Tomographic Angiogram (CTA) of the chest showed bilateral main stem pulmonary emboli (PE) with signs of RV strain. Initially EKG showed sinus tachycardia, right bundle branch block, and a S1Q3T3 pattern which resolved rapidly the next day. Patient was admitted, remained hemodynamically stable, and was treated with full dose of Enoxaparin subcutaneously. A follow up EKG was performed the next day, which showed complete resolution of initial findings. Follow up echocardiogram also showed rapid resolution of RV strain and complete restoration of RV size and function. Patient was eventually discharged home on full dose apixaban.

A survey of critical care pharmacists on venous thromboembolism prophylaxis dosing practices with enoxaparin in adult trauma patients

AbstractEnoxaparin is the preferred treatment for venous thromboembolism (VTE) prophylaxis in trauma patients, but timing of initiation, optimal dosing, and therapeutic drug monitoring remain controversial. The objective of this study was to evaluate enoxaparin VTE prophylaxis practices in adult trauma patients across trauma centers in the United States and compare results to current guideline recommendations. An online survey designed by the study investigators was sent to pharmacist members of the American College of Clinical Pharmacy (ACCP) Critical Care Practice Research Network (PRN) and residency directors of institutions with accredited Critical Care Pharmacy Residency programs in the fall of 2021. This survey queried pharmacists' self‐reported practices regarding enoxaparin dosing and monitoring in trauma patients. One hundred five responses were collected with an estimated response rate of 5.3%. Most respondents reported using a standard enoxaparin dose of 30 mg subcutaneously (SUBQ) every 12 h (67%; 70/104) in trauma patients with normal renal function and higher initial dosing for obese trauma patients (75%; 78/104). The most common body mass index (BMI) threshold for dose adjustments in obesity was a BMI ≥40 kg/m2; whereas 100 kg or more was commonly reported for a weight threshold. Multiple alternative enoxaparin dosing regimens were reported for obese and overweight patients. Of respondents who monitor anti‐Factor Xa (anti‐Xa) levels, 84% (61/73) reported monitoring peak levels with 47% (29/61) targeting a peak anti‐Xa goal of 0.2–0.4 units/ml. Seventy‐five percent (51/68) of respondents who adjust enoxaparin dosing based on anti‐Xa level monitoring reported adjusting doses by increments of 10 mg SUBQ every 12 h, and 41% (28/68) indicated having a pharmacist‐driven protocol for dose adjustments. Significant variation exists in enoxaparin dosing and monitoring strategies for VTE prophylaxis. Consensus among clinical practice guidelines is needed to standardize practice nationally.

Enoxaparin Posology According to Prothrombotic Status and Bleeding Risk in Hospitalized Patients with SARS-CoV-2 Pneumonia.

Some patients with COVID-19 have complex hypercoagulable abnormalities that are related to mortality. The optimal dosage of low molecular weight heparin in hospitalized patients with SARS-CoV-2 pneumonia is still not clear. Our objective is to evaluate the effects of adapting the dosage of low molecular weight heparin to thrombotic and bleeding risk scales in this setting. We performed a cohort, retrospective, observational, and analytical study at the Hospital Universitario of Jerez de la Frontera, with patients admitted with SARS-CoV-2 pneumonia from 1 October 2020 to 31 January 2021. They were classified according to whether they received prophylactic, intermediate, or therapeutic doses of enoxaparin. The primary endpoint was intrahospital mortality. Secondary endpoints were the need for invasive ventilation, thromboembolic events, bleeding, and the usefulness of thrombotic and bleeding scales. After binary logistic regression analysis, considering confounding variables, it was found that the use of enoxaparin at therapeutic doses was associated with lower mortality during admission compared to prophylactic and intermediate doses (RR 0.173; 95% CI, 0.038-0.8; p = 0.025). IMPROVE bleeding risk score correlated with a higher risk of minor bleeding (RR 1.263; 95% CI, 1.105-1.573; p = 0.037). In adult hospitalized patients with SARS-CoV-2 pneumonia presenting elevated D-dimer and severe proinflammatory state, therapeutic doses of enoxaparin can be considered, especially if bleeding risk is low according to the IMPROVE bleeding risk score.

ANAESTHETIC CONSIDERATIONS OF ANTI-PHOSPHOLIPID ANTIBODY SYNDROME IN PREGNANCY

Anti-phospholipid syndrome (APS) is a systemic autoimmune acquired disease characterised by vascular thrombosis or pregnancy complications with the presence of antiphospholipid antibodies. It is a rare disease affecting 40-50/100,000 population and 10%-15% of recurrent abortions. Perioperative management in obstetric APS undergoing caesarean section stresses on the management of anticoagulation and prior choice of anaesthetic technique. We report the case of 26 year old multigravida ,37 weeks of gestation diagnosed with APS since 8 weeks of gestation. She had previous three miscarriages with lupus anticoagulant(LAC) value of 45.6 (normal – 36.8), IgM and IgG anticardiolipin antibody values were 8.5µ/ml and 3.8µ/ml, respectively. She was prophylactically put on Aspirin 75mg orally and Enoxaparin 0.4IU subcutaneously every 24 hours. She presented to the obstetric department and was planned for emergency caesarean section . She received her usual dose of enoxaparin on the day of surgery but aspirin was omitted. Surgery was conducted under subarachnoid blockade. Anticoagulation resumed 12 hours after surgery .No maternal and fetal complications were noted

Dose adjusted prophylactic lovenox dosing in hepatic surgery

Background: Recommended prophylactic doses of enoxaparin are often associated with sub-prophylactic anti-Factor Xa (anti-Xa) levels. This study examines the safety and efficacy of using anti-Xa levels to achieve prophylactic enoxaparin levels in patients who underwent major hepatic surgery.

Venous Thromboembolism Prophylaxis with Enoxaparin Versus Unfractionated Heparin in Patients with Low Body Weight

Background Although reduced doses of enoxaparin have been studied in low body weight patients, no study has directly compared enoxaparin to unfractionated heparin for venous thromboembolism (VTE) prophylaxis in this population. Objective To determine the most safe and efficacious parenteral venous thromboembolism prophylaxis regimen for low body weight patients. Design Retrospective cohort. Methods Hospitalized patients weighing &lt; 55 kg receiving either enoxaparin or unfractionated heparin for VTE prophylaxis over a period of two and a half years were evaluated. Primary outcomes included rates of VTE and overall bleeding events. Secondary outcomes included rates of major and clinically relevant minor bleeding. Dosing regimens were analyzed to determine associations between dose, weight, creatinine clearance, VTE, and bleeding events. Primary and secondary outcomes were evaluated using Chi squared and Fischer's Exact tests. Results Three hundred and sixty-one patients contributed 400 episodes of VTE prophylaxis. Most patients were female (88%), had a Padua score ≥ 4 (82%) and were admitted to medical/surgical units (76%). VTE rates were 0.4% in patients receiving enoxaparin and 2.5% in patients receiving unfractionated heparin ( P = 0.334). Bleeding rates were 12% and 11% in the enoxaparin and unfractionated heparin groups, respectively ( P = 1). Patients receiving enoxaparin 30 mg daily had bleeding rates of 7.6% compared to 14.7% in patients receiving 40 mg daily ( P = 0.134). Patients receiving heparin twice daily had no bleeding events compared to 12.9% of patients receiving heparin three times daily ( P = 0.222). Conclusion Overall, no difference in VTE or bleeding rates were found between patients weighing &lt; 55 kg receiving enoxaparin versus unfractionated heparin, and there was no difference in bleeding or VTE events in the patients receiving enoxaparin 30 mg daily. Due to this, empirically reducing the dose of enoxaparin for VTE prophylaxis appears reasonable and safe in patients weighing &lt; 55 kg.

Enoxaparin adherence for venous thromboembolism prophylaxis in hospitalized patients with sickle cell disease

ABSTRACT Background Venous thromboembolism (VTE) is a common cause of morbidity and mortality in patients with sickle cell disease (SCD). Methods This retrospective study assessed adherence to prescribed enoxaparin for VTE prophylaxis in adults with SCD while hospitalized. A total of 172 encounters of 72 unique patients were evaluated between 1 January and 31 December 2019. Patients were grouped based on adherence to prescribed enoxaparin. Group 1 received 100% of doses ordered. Group 2 received between 99% and 1% of doses ordered. Group 3 received 0% of doses ordered. Results Only 45 encounters (32.3%) received 100% of ordered doses and 81 encounters (47%) did not receive any of the ordered enoxaparin doses. In total, only 37% of all prescribed enoxaparin doses were administered to patients. Conclusion This low level of administered enoxaparin is concerning in a patient population at an increased risk for VTE. VTE prophylaxis adherence needs to be addressed with each admission and, if appropriate, alterative options to enoxaparin should be considered.

The Effectiveness of the Intermediate and Therapeutic Doses of Enoxaparin in COVID-19 Patients: A Comparative Study of Factor Xa Inhibition

Background: Management of anticoagulant therapy in COVID-19 patients is critical. Low-molecular-weight heparin (LMWH) thromboprophylaxis is already recommended, and anti-Factor Xa (anti-FXa) monitoring has been used to titrate LMWH doses. Methods: Through a cross-sectional study, we evaluated anti-FXa activity in patients admitted to the ICU, receiving intermediate dose (30, 40, 50 mg, subcutaneously [SC], twice daily) or therapeutic dose (1 mg/kg, SC, Q12h) of enoxaparin to find whether the patients in these two groups achieved anti-FXa levels in the accepted thromboprophylaxis range. Results: The occurrence of deep vein thrombosis was 26% in the therapeutic-dose group and 17% in the intermediate-dose group. D-dimer values were nearly 3.5-fold higher in those who received a therapeutic dose of anticoagulants than in those who received intermediate-dose thromboprophylaxis. Patients in the therapeutic-dose group had significantly higher IL-6 levels (p ≤ 0.001). More than one-third of the patients in the therapeutic-dose group (n = 8; 42.18%) and approximately half of the patients in the intermediate-dose group (n = 12; 52.2%) achieved the target range level of anti-FXa. Patients who received therapeutic doses were more likely to have anti-FXa levels above the expected range (47.4 vs 13% in the intermediate-dose group; p < 0.05). Conclusion: Therapeutic dose of enoxaparin in critically ill COVID-19-infected patients did not reduce the incidence of thromboembolic events and, on the other hand, may predispose these patients to increased risk of bleeding by increasing anti-FXa activity above the desired level. Administration of intermediate-dose thromboprophylaxis is suggested to achieve anti-FXa levels in the accepted thromboprophylaxis range.

Management of venous thromboembolism in morbidly obese patients: a 10-year review.

Obesity is a known risk factor for venous thromboembolism (VTE) and poses a unique set of challenges in anticoagulation management. We report a 10-year experience of VTE management in morbidly obese patients. We conducted a retrospective analysis of VTE presentations to Northern Health, Victoria, Australia, from January 2011 to December 2020, with median follow-up of 44months. Morbidly obese patients (defined as weighing > 120kg) were compared to those ≤ 120kg. Patients with active malignancy were excluded. 194 VTE cases with weight > 120kg were compared to 2168 cases weighing ≤ 120kg. Patients > 120kg were more likely to present with unprovoked VTE (59.3% vs. 45.2%, p < 0.001) and major VTE (74.7% vs. 67.4%, p = 0.028). Overall, patients > 120kg were more likely to develop VTE recurrence after anticoagulation cessation (7.80 vs. 3.92 per 100-patient-years, HR 1.97, 95%CI 1.29-3.00), while there were no significant differences in major bleeding or 30-day all-cause mortality. There were no significant differences in outcomes in patients > 120kg treated with warfarin compared to direct oral anticoagulants (DOAC), or when comparing those treated with an uncapped (1mg/kg BD) vs. capped (< 1mg/kg) enoxaparin dosing regimen. Morbid obesity is associated with increased clot burden at presentation and VTE recurrence following anticoagulation cessation, without significant differences in bleeding compared to those ≤ 120kg. There were no significant differences in morbidly obese patients' outcomes when treated with warfarin or DOAC, or when treated with an uncapped or capped enoxaparin dosing strategy. Larger randomised controlled trials evaluating the safety of DOACs and different enoxaparin dosing strategies in patients > 120kg are warranted.

Administration of Prophylactic Enoxaparin on the Morning of Surgery Does Not Increase Risk of Blood Transfusion or Wound Drainage Following Internal Fixation of Geriatric Femur Fractures.

Despite standard use of chemoprophylaxis, 30-day incidence of venous thromboembolism after geriatric, those older than 60 years, femur fracture surgery is reported to be up to 10%. Missing one dose of enoxaparin has been proven to increase the risk of developing venous thromboembolism. It is commonplace to hold preoperative chemoprophylaxis the morning of surgery because of concern for intraoperative bleeding or wound drainage. We sought to determine whether administration of prophylactic enoxaparin the morning of surgery resulted in an increased rate of blood transfusion or wound drainage in geriatric patients undergoing femur fracture treatment. We retrospectively reviewed patients older than 60 years who underwent internal fixation of an isolated femur fracture, including femoral neck, intertrochanteric, subtrochanteric, femoral shaft, and distal femur fractures, at a Level 1 trauma center. Medical records, hospital billing data, and radiographs were reviewed to determine patient characteristics such as Charlson Comorbidity Index, enoxaparin dosing, packed red blood cell transfusion, and persistent wound drainage, defined as any drainage requiring utilization of closed incision negative pressure wound therapy. Thirty-day mortality served as the secondary outcome measure. Five hundred seven patients were included. One hundred sixty-four (32%) received enoxaparin on the morning of surgery, whereas 343 (68%) did not. 27% of patients received PRBC transfusion, and this did not differ between groups (27% vs. 28%, P = 0.72). Subgroup analysis of fixation strategies revealed no difference in the frequency of blood transfusion for any fixation type as related to the timing of enoxaparin dosage. Utilization of closed incision negative pressure wound therapy for the treatment of postoperative wound drainage did not differ between dosing groups. No difference was observed in thirty-day mortality between groups (2.4% vs. 2.7%, P = 0.9). Administration of a prophylactic dose of enoxaparin on the morning of surgery does not seem to increase the rate of postoperative blood transfusion or wound drainage after fixation of geriatric femur fracture. Level III, therapeutic.

Effects of a single subcutaneous dose of enoxaparin on veterinary viscoelastic coagulation monitor variables in healthy cats: Double blind, placebo controlled cross-over trial.

Cats placed on anticoagulant medication require frequent monitoring. The veterinary viscoelastic coagulation monitor (VCM-Vet) could provide a convenient and cost-effective monitoring, enabling therapeutic decision making. Enoxaparin will lead to changes in VCM-Vet variables and these will correlate with antiXa activity. Twenty-one healthy cats. Cats were randomized to receive either enoxaparin (1mg/kg) subcutaneously or 0.9% NaCl (equal volume) and crossed over with a 7-day washout period. The investigators were blinded to group allocation until data analysis. Jugular blood samples were drawn at time 0, and 2, 4, and 8hours after injection for VCM-Vet analysis within 2min of collection. Citrated plasma was frozen at -80°C for antiXa activity analysis. A Generalized Linear Model was completed to assess changes between baseline measurements and all time points. Significant differences between the enoxaparin-treated cats and controls at for T0h and T2h were found and presented as mean ± SD for clotting time (enoxaparin, 593.4 ± 78.0s; control, 448.5 ± 50.3s, P < .001), clot formation time (enoxaparin, 183.1 ± 41.7s; control, 155.4 ± 28.0s, P=.001), and alpha angle (enoxaparin, 52.4 ± 6.1°; control, 56.9 ± 3.7s, P=.003). AntiXa activity was significantly different between T0 and all other timepoints for the enoxaparin group (P < .001). There was no correlation between changes in clotting time and antiXa activity. The VCM-Vet detects a difference at 2hours after single-dose enoxaparin administration and it can be useful for anticoagulant therapy monitoring in cats.

Standard dosing of enoxaparin versus unfractionated heparin in critically ill patient with COVID-19: a multicenter propensity-score matched study.

Thrombotic events are common in critically ill patients with COVID-19 and have been linked with COVID-19- induced hyperinflammatory state. In addition to anticoagulant effects, heparin and its derivatives have various anti-inflammatory and immunomodulatory properties that may affect patient outcomes. This study compared the effectiveness and safety of prophylactic standard-doses of enoxaparin andunfractionated heparin (UFH) in critically ill patients with COVID-19. METHODS: A multicenter, retrospective cohort study included critically ill adult patients with COVID-19 admitted to the ICU between March 2020 and July 2021. Patients were categorized into two groupsbased on the type of pharmacological VTE thromboprophylaxis given in fixed doses (Enoxaparin 40mg SQevery 24hours versus UFH 5000 Units SQevery 8hours) throughout their ICU stay.The primary endpoint was all cases of thrombosis. Other endpoints were considered secondary. Propensity score (PS)matching was used to match patients (1:1 ratio)between the two groups based on the predefined criteria. Multivariable logistic, Cox proportional hazards, and negative binomial regression analysis were used as appropriate. RESULTS: A total of 306 patients were eligible based on the eligibility criteria; 130 patients were included after PS matching (1:1 ratio). Patients who received UFH compared to enoxaparin had higher all thrombosis events at crude analysis (18.3% vs. 4.6%; p-value = 0.02 as well in logistic regression analysis (OR: 4.10 (1.05, 15.93); p-value = 0.04). Although there were no significant differences in all bleeding cases and major bleeding between the two groups (OR: 0.40 (0.07, 2.29); p-value = 0.31 and OR: 1.10 (0.14, 8.56); p-value = 0.93, respectively); however, blood transfusion requirement was higher in the UFH group but did not reach statistical significance (OR: 2.98 (0.85, 10.39); p-value = 0.09). The 30-day and in-hospital mortality were similar between the two groups at Cox hazards regression analysis. In contrast, hospital LOS was longer in the UFH group; however, it did not reach the statistically significantdifference (beta coefficient: 0.22; 95% CI: -0.03, 0.48; p-value = 0.09). Prophylactic enoxaparin use in critically ill patients with COVID-19 maysignificantly reduce all thrombosis cases with similar bleeding risk compared to UFH.

Abstract 13870: Ventricular Fibrillation Arrest in a 27-Year-Old Woman Due to Takotsubo Cardiomyopathy

Introduction: Sudden cardiac death in young patients may be due to coronary artery disease, primary electrical disease, cardiomyopathy, or congenital anomalies. We explore potential causes for sudden cardiac arrest in a young patient. Case Description: A 27-year-old woman was found unconscious. Initial rhythm showed ventricular fibrillation. Cardiopulmonary resuscitation was done for 5 minutes before return of spontaneous circulation. ECG showed ST elevations in aVL, V4, and V5. She was admitted for therapeutic temperature management. Troponin peaked at 1.86 ng/mL on the evening of arrival. Transthoracic echocardiography (TTE) demonstrated hypokinesis of the mid to distal septum, anterior wall, and apex (Figure 1). Repeat TTE 3 days later showed resolution of the wall motion abnormalities. She reported marijuana use and a domestic dispute with her significant other the night prior. Coronary CT angiography showed calcium score of 0 with normal coronary anatomy, no significant coronary artery stenosis, and incidental finding of bilateral pulmonary artery filling defects. Lower limb venous duplex was unremarkable. Therapeutic dose of enoxaparin was started. Cardiac MRI showed no myocardial infarction, scar, or infiltrative disease. An electrophysiology study revealed adequate QT shortening during epinephrine infusion and no inducible ventricular arrhythmias. Genetic testing was unremarkable. She was discharged with a wearable defibrillator before ultimately receiving a subcutaneous implantable cardioverter-defibrillator. Discussion: The presentation of transient regional wall motion abnormalities, with ST-segment elevations and negative ischemic workup, is highly suggestive of Takotsubo cardiomyopathy, mid-ventricular variant. Marijuana use is a risk factor, and the domestic dispute is a potential emotional trigger. This case highlights Takotsubo cardiomyopathy as a possible cause of sudden cardiac arrest in young patients.

Venous Thromboembolism Chemoprophylaxis in Knee Arthroscopy: A Break-Even Analysis of Cost

Background: Symptomatic venous thromboembolism (VTE) is a serious and costly complication after knee arthroscopy. There continues to be debate regarding the use of VTE prophylaxis after knee arthroscopy, and minimal research has explored its cost-effectiveness. Hypothesis: Both aspirin and enoxaparin would be cost-effective in preventing symptomatic VTE. Study Design: Economic and decision analysis; Level of evidence, 3. Methods: The literature was searched and the TriNetX research database was queried to determine a range of initial rates of VTE. An open-access retail database was used to determine the mean retail price for aspirin (325 mg) and enoxaparin (30 mg and 40 mg). Our institutional records were used to determine the cost of treating VTE. A “break-even” analysis was then performed to determine the absolute risk reduction necessary to make these drugs cost-effective. This value was then used to calculate the number of patients who would need to be treated (NNT) to prevent a single VTE while still breaking even on cost. Results: The cost of treating VTE was $9407 (US Dollars). Aspirin (325 mg), enoxaparin (30 mg), and enoxaparin (40 mg) were found to cost $1.86, $188.72, and $99.99, respectively. The low, TriNetX, and high rates of VTE were 0.34%, 0.86%, and 10.9%, respectively. Aspirin was cost-effective at all 3 rates if the initial rate decreased by 0.02% (NNT = 5058). Both formulations of enoxaparin were cost-effective at the high initial rate if they decreased by 2.01% (NNT = 50) and 1.06% (NNT = 94), respectively. However, at the low and TriNetX rates, the 2 doses of enoxaparin were not cost-effective because their final break-even rate exceeded the initial VTE rate. Conclusion: Aspirin and, in some cases, enoxaparin are cost-effective treatments for VTE prophylaxis after knee arthroscopy.

Low molecular weight heparin for venous thromboembolism prophylaxis in general Intensive Care Unit patients: an anti-factor Xa level-based approach.

Venous thromboembolism (VTE) in the Intensive Care Unit (ICU) is associated with significant morbidity and mortality therefore prevention is imperative to reduce its burden. VTE prophylaxis in ICU patients is primarily pharmacological using low molecular weight heparin (LMWH). Plasma anti-factor Xa (anti-FXa) levels may be used to measure LMWH activity. This study aims to determine the proportion of acutely ill patients in a general ICU receiving standard VTE prophylaxis that achieve adequate peak or trough anti-FXa prophylactic levels and to determine the effect of LMWH dose adjustment in patients not achieving adequate anti-FXa prophylactic levels. Peak and trough anti-FXa levels were measured at four and 23 hours respectively after receiving the second consecutive daily enoxaparin 40 mg sc injection. Patients in whom peak anti-FXa levels were found to be sub-prophylactic (<0.2 IU/mL), were dose escalated to enoxaparin 60 mg once daily. Peak and trough levels were repeated as above. Sixty-one percent of study patients (N.=46) were found to have sub-prophylactic peak anti-FXa levels. Twenty-seven patients received an increased enoxaparin dose of 60 mg/d. Of these, nine patients (33.3%) still failed to achieve the target prophylactic peak anti-FXa level (0.2-0.4 IU/mL). Male gender and high body mass index (BMI) were significantly and strongly correlated with sub-prophylactic anti-FXa levels. Most ICU patients in this study did not achieve recommended prophylactic anti-FXa levels while receiving a standard dose of enoxaparin and these levels failed to increase after enoxaparin dose escalation in a significant proportion of patients. High BMI and male gender are associated with sub-prophylactic levels of anti-FXa in critically ill patients.

Clinical evaluation of the safety and efficacy of enoxaparin in patients with COVID-19.

Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2), increases thrombotic risk in hospitalised patients. The rate of thrombosis in patients with COVID-19 is unclear. The role of heparin, frequently used in the management of hospitalised patients, also needs to be clarified. In this study, we investigated the efficacy and safety of enoxaparin given at prophylactic or therapeutic dose in hospitalised patients with COVID-19, and evaluated its role in the development of disease in terms of mortality, and incidence of thrombotic and bleeding events. We included 141 patients with SARS-CoV-2 infection, admitted to five different wards (one intensive care unit, 2 sub-intensive care units, and 2 general infectious disease units) of Cotugno Hospital, a tertiary care hospital in Naples, Italy, between March and May 2020. Over a median time of 17 days (IQR 11-25), enoxaparin was given to 90/141 patients (63.8%) of whom 65 took a prophylactic and 25 a therapeutic dose. We documented 14 episodes of thrombosis (9.9%); almost all were cases of pulmonary embolism. No significant difference in terms of thromboembolic prevention was found between those patients not receiving anticoagulants and those on prophylactic or therapeutic dose of enoxaparin. Five episodes of major bleeding occurred (3.5%); therapeutic dose of enoxaparin was associated with a greater bleeding risk than prophylactic dose (p=0.002). During follow-up, 31 patients (22%) died; these were mostly elderly men with two or more comorbidities at admission. No advantages of enoxaparin, either as prophylaxis or at high doses, in terms of mortality were observed. At multivariate analysis, low estimated glomerular filtration rate, and high total bilirubin and fasting hyperglycemia were independently associated with a higher mortality. We did not observe advantages in terms of either thromboembolic prevention or mortality of enoxaparin, which however was more frequently used in patients with more severe disease. Prophylactic enoxaparin was not seen to be associated with bleeding risk.