Antithrombotic Management After Peripheral Lower‑Limb Bypass Surgery

Standard Post‑operative Antiplatelet Therapy

Aspirin 75–100 mg daily should be prescribed for life after peripheral artery bypass surgery – Class I, Level A recommendation (strong guideline support)【1】【2】【3】
Clopidogrel 75 mg daily is an equally effective alternative to aspirin and may be preferred in selected patients – Class I, Level A【3】【4】
Single antiplatelet therapy reduces major adverse cardiovascular events (MACE) and is the default strategy for most bypass patients – Class I, Level A【3】【4】

Aspirin plus clopidogrel should be considered for at least 1 month after a below‑knee prosthetic bypass, with extension up to 12 months based on bleeding risk – Class IIa, Level B【1】【2】
DAPT provides no additional benefit for autologous vein grafts; single antiplatelet therapy remains standard – Class III (no benefit), Level B【1】【2】

Low‑dose rivaroxaban 2.5 mg twice daily combined with low‑dose aspirin reduces both MACE and major adverse limb events (MALE) after revascularisation – Class IIa, Level A【3】【4】
The benefit is most pronounced in patients with chronic limb‑threatening ischemia, prior amputation or revascularisation, and high‑risk comorbidities (heart failure, diabetes, polyvascular disease) – Class IIa, Level A【4】
This regimen increases ISTH major bleeding risk, especially when clopidogrel is continued beyond 1 month – Class IIb, Level B【4】

Warfarin may be used for high‑risk venous conduits with poor runoff, targeting an INR of 3.0–4.5 – Class IIb, Level B【2】【4】
Warfarin is associated with a 1.9‑fold increase in major bleeding and a 1.3‑fold increase in fatal bleeding – Class III (harm), Level B【4】
A modest benefit has been observed for prosthetic grafts with poor runoff, but routine use is not recommended because of bleeding risk – Class III, Level B【4】【1】【2】

Full‑dose anticoagulation should not be employed routinely to lower MACE or MALE in peripheral artery disease patients without another indication – Class III, Level A【3】

Resume antiplatelet therapy within 24 hours after surgery for most patients – Class I, Level A【5】【6】
For low‑to‑moderate bleeding risk, therapy may be restarted on the evening of the procedure (Day 0) – Class I, Level A【5】【7】
For high bleeding risk, delay restart to 48–72 hours post‑operatively – Class I, Level A【5】【7】
Before restarting, assess surgical site haemostasis, bleeding history, body habitus, and coagulation status – Class I, Level A【6】

Lifelong antiplatelet therapy is advised after any peripheral bypass – Class I, Level A【1】【2】【3】
For prosthetic grafts receiving DAPT, a minimum of 1 month is required; extension to up to 12 months may be considered based on bleeding risk – Class IIa, Level B【1】【2】
After endovascular revascularisation, DAPT for 1–6 months may be reasonable, though supporting evidence is limited – Class IIb, Level C【3】【4】

In patients needing full‑intensity anticoagulation for atrial fibrillation or mechanical valves, adding a single antiplatelet agent is reasonable if bleeding risk is not high – Class IIa, Level B【3】
Any additional antiplatelet therapy after endovascular procedures should be kept brief – Class IIb, Level B【4】
Direct oral anticoagulants (DOACs) are preferred over warfarin when feasible – Class I, Level A【6】【8】

Do not use DAPT routinely for venous grafts; registry data show no benefit for limb loss, re‑intervention, or mortality – Class III, Level B【1】【2】
Avoid full‑dose anticoagulation without a specific indication (e.g., atrial fibrillation); it raises bleeding without improving limb outcomes – Class III, Level A【3】
Do not continue DAPT indefinitely; beyond the recommended duration the bleeding risk outweighs any incremental benefit – Class III, Level A【1】【2】