TY - JOUR
T1 - Weight-Based Compared with Fixed-Dose Enoxaparin Prophylaxis after Cesarean Delivery
T2 - A Randomized Controlled Trial
AU - Bruno, Ann M.
AU - Allshouse, Amanda A.
AU - Campbell, Heather M.
AU - Branch, D. Ware
AU - Lim, Ming Y.
AU - Silver, Robert M.
AU - Metz, Torri D.
N1 - Publisher Copyright:
© 2022 by the American College of Obstetricians and Gynecologists.
PY - 2022/10/1
Y1 - 2022/10/1
N2 - OBJECTIVE:To evaluate fixed compared with weight-based enoxaparin dosing to achieve prophylactic anti-Xa levels after cesarean delivery.METHODS:Individuals meeting institutional criteria for enoxaparin thromboprophylaxis after cesarean delivery were randomly allocated to fixed (40 mg daily for body mass index [BMI, calculated as weight in kilograms divided by height in meters squared] lower than 40; 40 mg every 12 hours for BMI 40 or higher) or weight-based (0.5 mg/kg every 12 hours) enoxaparin dosing. Enoxaparin was initiated during inpatient hospitalization and continued at discharge for 14 days. Those with contraindication to anticoagulation, plan for therapeutic anticoagulation, or known renal impairment were excluded. The trial was unmasked. The primary outcome was prophylactic (0.2-0.6 international units/mL) peak anti-Xa level 4-6 hours after at least the third enoxaparin dose (at steady state). Secondary outcomes included subprophylactic and supraprophylactic peaks, outpatient peak, and venous thromboembolism (VTE) and wound complications in the first 6 weeks postpartum. Sample size of 121 per group was planned. At interim analysis with 50% enrollment, the trial was stopped early for efficacy. Primary analyses followed intention-to-treat principle with worst-case imputation for missing outcomes. Secondary analyses were complete case.RESULTS:From June 2020 to November 2021, 74 individuals were randomized to weight-based enoxaparin and 72 to fixed-dose enoxaparin. Those who received weight-based dosing were more likely to achieve prophylactic anti-Xa levels than those who received fixed dosing in primary analysis (49/74 [66%] vs 32/72 [44%], relative risk [RR] 1.49, 95% CI 1.10-2.02) and secondary analysis (49/60 [82%] vs 32/57 [56%], RR 1.45, 95% CI 1.12-1.88). Subprophylactic levels occurred more frequently with fixed dosing; supraprophylactic levels did not differ significantly by dosing. At the outpatient postoperative visit, 52% of participants (15/29) with weight-based dosing compared with 15% (5/33) with fixed dosing achieved prophylactic peak anti-Xa level (RR 3.41, 95% CI 1.42-8.24). There were no VTEs in either group. Wound complications occurred in five individuals (7%) with weight-based enoxaparin dosing compared with one individual (1%) with fixed enoxaparin dosing (RR 4.86, 95% 0.58-40.63).CONCLUSION:Weight-based dosing was more effective than fixed enoxaparin dosing in achieving prophylactic peak anti-Xa levels after cesarean delivery.CLINICAL TRIAL REGISTRATION:ClinicalTrials.gov, NCT04305756.
AB - OBJECTIVE:To evaluate fixed compared with weight-based enoxaparin dosing to achieve prophylactic anti-Xa levels after cesarean delivery.METHODS:Individuals meeting institutional criteria for enoxaparin thromboprophylaxis after cesarean delivery were randomly allocated to fixed (40 mg daily for body mass index [BMI, calculated as weight in kilograms divided by height in meters squared] lower than 40; 40 mg every 12 hours for BMI 40 or higher) or weight-based (0.5 mg/kg every 12 hours) enoxaparin dosing. Enoxaparin was initiated during inpatient hospitalization and continued at discharge for 14 days. Those with contraindication to anticoagulation, plan for therapeutic anticoagulation, or known renal impairment were excluded. The trial was unmasked. The primary outcome was prophylactic (0.2-0.6 international units/mL) peak anti-Xa level 4-6 hours after at least the third enoxaparin dose (at steady state). Secondary outcomes included subprophylactic and supraprophylactic peaks, outpatient peak, and venous thromboembolism (VTE) and wound complications in the first 6 weeks postpartum. Sample size of 121 per group was planned. At interim analysis with 50% enrollment, the trial was stopped early for efficacy. Primary analyses followed intention-to-treat principle with worst-case imputation for missing outcomes. Secondary analyses were complete case.RESULTS:From June 2020 to November 2021, 74 individuals were randomized to weight-based enoxaparin and 72 to fixed-dose enoxaparin. Those who received weight-based dosing were more likely to achieve prophylactic anti-Xa levels than those who received fixed dosing in primary analysis (49/74 [66%] vs 32/72 [44%], relative risk [RR] 1.49, 95% CI 1.10-2.02) and secondary analysis (49/60 [82%] vs 32/57 [56%], RR 1.45, 95% CI 1.12-1.88). Subprophylactic levels occurred more frequently with fixed dosing; supraprophylactic levels did not differ significantly by dosing. At the outpatient postoperative visit, 52% of participants (15/29) with weight-based dosing compared with 15% (5/33) with fixed dosing achieved prophylactic peak anti-Xa level (RR 3.41, 95% CI 1.42-8.24). There were no VTEs in either group. Wound complications occurred in five individuals (7%) with weight-based enoxaparin dosing compared with one individual (1%) with fixed enoxaparin dosing (RR 4.86, 95% 0.58-40.63).CONCLUSION:Weight-based dosing was more effective than fixed enoxaparin dosing in achieving prophylactic peak anti-Xa levels after cesarean delivery.CLINICAL TRIAL REGISTRATION:ClinicalTrials.gov, NCT04305756.
UR - http://www.scopus.com/inward/record.url?scp=85139299376&partnerID=8YFLogxK
U2 - 10.1097/AOG.0000000000004937
DO - 10.1097/AOG.0000000000004937
M3 - Article
C2 - 36075079
AN - SCOPUS:85139299376
SN - 0029-7844
VL - 140
SP - 575
EP - 583
JO - Obstetrics and gynecology
JF - Obstetrics and gynecology
IS - 4
ER -