VTE Incidence After Rivaroxaban + Aspirin or SAPT After Lower-limb Revascularization

Incidence of Venous Thromboembolism After Lower Limb Revascularization in Patients Receiving Rivaroxaban 2.5 Mg Bid + Aspirin 100 Mg Versus Single Antiplatelet Treatment - a Randomized Clinical Trial

Venous thromboembolism (VTE) has a high prevalence in patients with multiple comorbidities undergoing complex surgical procedures. Sometimes, extended prophylaxis for VTE with KLMWH or direct oral anticoagulants (DOACs) is necessary. Currently, there is no consensus in the literature regarding the use of DOACs for extended VTE prophylaxis in patients undergoing lower limb revascularization (LLR). Objective: To evaluate the use of DOACs (already approved to reduce MACE and MALE) in VTE prophylaxis in patients undergoing LLR.

The goal of this clinical trial is to evaluate the 30-day VTE incidence in patients submitted to endovascular or open surgery for lower limbs revascularization treated with either rivaroxaban 2.5 mg bid + aspirin 100 mg or single antiplatelet agents (SoC). The main questions it aims to answer are:

Does rivaroxaban 2.5 mg + aspirin reduce the incidence of 30-day VTE?

Researchers will compare rivaroxaban 2.5 mg bid + aspirin 100 mg to a single antiplatelet agent to check comparative VTE incidence.

Participants will:

Take either rivaroxaban 2.5 mg bid + aspirin continuously or single antiplatelet agent (clopidogrel for 3 months followed by aspirin 100 mg for endovascular procedures or aspirin for oper procedures) Visit the clinic once every 2 weeks for checkups and tests, and a mandatory Doppler ultrasound at day 30 Keep a diary of their symptoms

Study Population The study population will consist of patients hospitalized in the vascular surgery ward at the Hospital das Clínicas/Brazilian Hospital Services Company-Federal University of Pernambuco (HC/EBSERH-UFPE) who undergo arterial revascularization surgery of the lower limbs (LL) via angioplasty (ATP) or bypass surgery.

The study will determine the sample size by the criteria established by Resolution 466/12 of the National Health Council. The estimated sample size is 200 research participants, with 100 in the study group and 100 in the control group. If the degree of dispersion is high, the number of research participants may be adjusted.

Study Design A single-center randomized clinical trial. Randomization will be performed using the REDCap platform. Due to the nature of the procedure, blinding will not be possible.

Considering an acceptable margin of error (5%), a confidence level of 95%, and a prevalence of 50% for venous diseases, with a heterogeneity level of 50%.

Selection of Research Participants The selection of research participants will follow specific inclusion and exclusion criteria. After selection, participants will be randomly assigned to the Study Group (SG) or the Control Group (CG).

CG (Control Group): Will receive standard treatment as described in the literature: Aspirin (ASA) 100 mg once daily for patients undergoing lower limb bypass revascularization, and ASA 100 mg once daily combined with Clopidogrel 75 mg once daily for patients undergoing lower limb angioplasty.

SG (Study Group): Will receive ASA 100 mg once daily plus Rivaroxaban 2.5 mg twice daily for patients undergoing bypass or angioplasty revascularization.

A total of 100 patients will be included in the study, equally divided between the control and study groups. Randomization will be performed via the REDCap platform.

Inclusion Criteria:

1. Be adults of any age and gender.
2. Have critical limb ischemia with a proposed revascularization treatment (either via ATP or bypass surgery) at the Vascular Surgery Service of HC/EBSERH - UFPE.
3. Sign the informed consent form (ICF) (Appendix 2).

Exclusion Criteria:

1. Experience a symptomatic VTE event during hospitalization, as they will require full anticoagulation rather than prophylactic anticoagulation.
2. Have any contraindications to Rivaroxaban.
3. Do not return for the 30-day postoperative follow-up visit.