Comparison of the Efficacy and Safety of Two Enoxaparin Dosing Regimens in Patients After Chest Surgery

Introduction

Surgery is a significant risk factor for the development of thromboembolic disease. Procedures with the highest risk of thromboembolic disease include orthopedic and trauma surgeries on the limbs, while chest and abdominal surgeries fall into the moderate-risk category. Routine thromboprophylaxis is thus recommended for these types of procedures, with low molecular weight heparins, such as enoxaparin, being most commonly used in the perioperative period.

This raises the yet-unanswered key question of what the optimal dose of enoxaparin is for patients undergoing chest surgery. To address this, a multicenter clinical study compared the efficacy and safety of fixed dosing to weight-adjusted dosing of enoxaparin.

Methodology and Study Course

The study included a total of 131 patients, who were divided into two groups. The first group (n = 65) received enoxaparin at a dose of 40 mg once daily, while the second group (n = 66) received weight-adjusted dosing of enoxaparin: 30 mg once daily for patients weighing < 70 kg, 40 mg once daily for those weighing 70–89.9 kg, and 50 mg once daily for patients weighing ≥ 90 kg.

The primary goal was to determine the peak level of anti-Xa. Secondary goals included determining the trough level of anti-Xa, the incidence of symptomatic thromboembolic disease, and clinically significant bleeding within a 90-day period.

Results

All 131 participants completed the study. No significant difference was observed in the proportion of patients with adequately adjusted anticoagulant therapy between the weight-adjusted dosing group and the fixed dose group (peak anti-Xa ≥ 0.3 IU/ml; 44.3% vs. 48.2%; p = 0.67). Similarly, there was no significant difference between the groups in the proportion of patients exceeding the upper therapeutic range (peak anti-Xa ≥ 0.5 IU/ml; 3.3% vs. 3.6%; p = 1.00). No significant difference was observed between the groups in trough levels of anti-Xa either.

The incidence of symptomatic thromboembolic disease and clinically significant bleeding within 90 days was low and did not differ significantly between the groups (0% vs. 3.1%).

Conclusion

The results of the study indicate that weight-adjusted dosing of enoxaparin does not increase efficacy or safety compared to fixed dosing in patients undergoing chest surgery. Both dosing regimens exhibit high efficacy and safety with a low incidence of thromboembolic disease and clinically significant bleeding.

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Source: Pannucci C. J., Fleming K. I., Bertolaccini C. et al. Fixed or weight-tiered enoxaparin after thoracic surgery for venous thromboembolism prevention. Ann Thorac Surg 2020 Jun; 109 (6): 1713–1721, doi: 10.1016/j.athoracsur.2019.12.058.