Apixaban vs Enoxaparin Following Microsurgical Breast Reconstruction-An RCT

A Randomized Controlled Trial Comparing Apixaban Versus Enoxaparin Following Microsurgical Breast Reconstruction

Subcutaneous enoxaparin is currently the gold standard for VTE chemoprophylaxis. However, the efficacy of chemoprophylaxis with subcutaneous enoxaparin is affected by patient-level factors, thus, resulting in VTE events despite guideline-compliant prophylaxis. A population at particular risk is the growing number of patients who undergo autologous breast reconstruction. Direct oral anticoagulants (DOAC) might be a less invasive, yet, more efficacious mode of chemoprophylaxis in this patient population. Hence, the proposed work has the potential to cause a paradigm shift in chemoprophylaxis guidelines in a large population of patients undergoing plastic surgery.

Study Overview

• Status: Completed
• Conditions: Venous Thromboembolism
• Intervention / Treatment: Drug: Apixaban 2.5 MG Oral Tablet; Drug: Enoxaparin 40Mg/0.4mL Prefilled Syringe

• Study Type: Interventional
• Enrollment (Actual): 82
• Phase: Phase 2; Phase 1

Contacts and Locations

Study Locations

• United States
  • California
    • Stanford, California, United States, 94305
      • Stanford University Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 89 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Adult (>18 years) women
• Scheduled to undergo unilateral or bilateral microsurgical breast reconstruction with free abdominal flaps (i.e. muscle-sparing transverse rectus abdominis musculocutaneous [TRAM] and/or deep inferior epigastric artery perforator [DIEP]) flap)
• Caprini score of 6 or greater.
• Ability to understand and the willingness to sign a written informed consent document.

Exclusion Criteria:

• Contraindication to the use of apixaban or enoxaparin
• Active bleeding
• History of bleeding disorder
• History of coagulopathy
• History of heparin-induced thrombocytopenia
• History of liver disease
• History of renal disease (creatinine clearance <30 mL/min; serum creatinine >1.6 mg/dL)
• Major neurosurgical intervention (brain/spine) within the past 90 days
• Ophthalmologic procedure within the past 90 days
• Uncontrolled hypertension
• History of alcohol and/or substance abuse
• Need for therapeutic anticoagulation
• Pregnant or Nursing

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Apixaban; Patients assigned to this group will receive Apixaban 2.5 mg PO BID starting 12 hours after completing skin closure.	Drug: Apixaban 2.5 MG Oral Tablet; Patients will be assigned to the respective study groups postoperatively upon arrival in the post-anesthesia care unit. Hence, surgeons are blinded at the time of surgery as to study group assignment. Chemoprophylaxis will continue for the duration of the hospitalization.
Active Comparator: Enoxaparin; Patients assigned to this group will receive Enoxaparin 40 mg SC QD starting 12 hours after completing skin closure.	Drug: Enoxaparin 40Mg/0.4mL Prefilled Syringe; Patients will be assigned to the respective study groups postoperatively upon arrival in the post-anesthesia care unit. Hence, surgeons are blinded at the time of surgery as to study group assignment. Chemoprophylaxis will continue for the duration of the hospitalization.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Apixaban vs. Enoxaparin - Number of Participants With Bleeding Events	To examine the rate of bleeding events in patients receiving oral apixaban versus subcutaneous enoxaparin following microsurgical breast reconstruction	90-day events

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Apixaban vs. Enoxaparin - Number of Participants With Venous Thromboembolism (VTE) Events	To examine the rate of VTE events in patients receiving oral apixaban versus subcutaneous enoxaparin following microsurgical breast reconstruction	90 days

Collaborators and Investigators

• Sponsor: Stanford University
• Investigators: Principal Investigator: Arash Momeni, MD, Stanford University

Study record dates

Study Major Dates

• Study Start (Actual): August 12, 2020
• Primary Completion (Actual): June 19, 2024
• Study Completion (Actual): June 19, 2024

Study Registration Dates

• First Submitted: August 5, 2020
• First Submitted That Met QC Criteria: August 5, 2020
• First Posted (Actual): August 7, 2020

Study Record Updates

• Last Update Posted (Actual): June 22, 2025
• Last Update Submitted That Met QC Criteria: June 10, 2025
• Last Verified: June 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Embolism and Thrombosis; Thromboembolism; Venous Thromboembolism; Molecular Mechanisms of Pharmacological Action; Protease Inhibitors; Enzyme Inhibitors; Fibrin Modulating Agents; Fibrinolytic Agents; Anticoagulants; Factor Xa Inhibitors; Antithrombins; Serine Proteinase Inhibitors; Enoxaparin; Apixaban
• Other Study ID Numbers: IRB-49355

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No