Anticoagulant activity of enoxaparin and unfractionated heparin for venous thromboembolism prophylaxis in obese patients undergoing sleeve gastrectomy

Abstract

Background: One risk of bariatric surgery is venous thromboembolism and the optimal strategy to reduce risk requires further clarification. Objectives: The objectives of this study were to identify antiXa goal attainment with the institutional standard chemoprophylaxis, analyze discordance between antiXa and thrombin generation assay (TGA) in terms of adequacy of anticoagulation, and to identify correlations between patient characteristics or covariates and markers of coagulation status. Setting: Large academic medical center in Northeastern United States. Methods: A total of 60 sleeve gastrectomy patients were enrolled in this institutional review board-approved, prospective cohort study. Patients received the institutional standard prophylactic therapy (subcutaneous enoxaparin 40 mg twice daily or unfractionated heparin [UFH]). The UFH dose was weight based, 5000 units ( < 120 kg) or 7500 units ( ≥120 kg) every 8 hours. Various measures of coagulation status were measured at or near steady state. Results: Patients receiving enoxaparin achieved goal antiXa more frequently compared with the UFH group, and statistical significance was demonstrated (93.8 % versus 4.5%, respectively; P < .0001). Target endogenous thrombin potential reduction from baseline was more frequently obtained in the enoxaparin group versus UFH (50% versus 27.7%, respectively; P = .12). AntiXa was below the limit of detection for the majority of UFH patients; while TGA suggested patients did experience anticoagulation at some level of effectiveness. Endogenous thrombin potential change in the enoxaparin group was correlated to several measures of body composition. Conclusions:Patients receiving enoxaparin achieved goal antiXa more often versus UFH. There was discordance between antiXa and TGA-based assessment of coagulation status. TGA may provide a more robust assessment of the adequacy of chemoprophylaxis. (Surg Obes Relat Dis 2019;15:363-373.)

Dosage of Anticoagulants in Obesity: Recommendations Based on a Systematic Review

“…Overall, the five prospective cohort studies on enoxaparin included a low number of obese patients (n ¼ 39-223), and, if any, only a few cases of VTE and bleedings were observed. [9][10][11][12][13] Therefore, their conclusions mainly relied on biochemical measures. Three studies, collectively, seemed to agree on the notion that 40 mg once or twice daily is associated with a relatively low proportion of patients reaching the biochemical target, especially in patients > 150 kg.…”

“…9-11 However, Brunetti et al did observe that 40 mg twice daily was sufficient in the majority of patients, but a wider anti-Xa range of 0.1 to 0.5 IU/mL was utilized in this study. 12 The largest prospective study by Borkgren-Okonek et al included 223 patients and found satisfactory anti-Xa levels and only a single VTE event with enoxaparin 40 mg twice daily during hospitalization, followed by 40 mg once daily for 10 days after discharge for patients with BMI 50 kg/m 2 and 60 mg once daily for patients with BMI > 50 kg/m 2 . 13 Nine retrospective studies, based on medical chart review, evaluating enoxaparin, were found.…”

Comparison of Anti-factor Xa Levels in Female and Male Patients with Obesity After Enoxaparin Application for Thromboprophylaxis

“…Many previous studies have tested different dosages of enoxaparin for patients with obesity [ 12 – 14 , 19 , 23 , 24 ]. Most of them focused on the optimal dosage regimen while not taking sex into account.…”

“…Anti-factor Xa activity was measured 4-5 h after enoxaparin application on the third day after surgery. An anti-factor Xa activity between 0.1 and 0.4 U/mL was chosen as the target range for thromboprophylaxis, according to the literature [15][16][17][18][19] and our local laboratory values. The anti-factor Xa assay quantitatively measures the amount of factor Xa left in the sample in a chromogenic assay and is inversely proportional to the amount of LMWH [6].…”

Correlation between thrombodynamics test levels and the incidence of venous thromboembolic complications in prostate cancer patients undergone radical prostatectomy. Retrospective study

“…Анти-Xa активность -это лабораторный показатель, отражающий противосвертывающую активность НМГ. Данные исследований, проведенных у пациентов, получающих профилактические дозировки НМГ, лабораторный контроль которых осуществлялся с помощью данного метода, оказались противоречивы [13][14][15].…”