In a stable patient with a prior ischemic stroke more than three months ago, how many days before total knee arthroplasty should low‑dose aspirin (Ecospirin, aspirin) be stopped, and what factors influence whether it should be continued?

Perioperative Aspirin Management in Prior Ischemic Stroke Patients Undergoing Total Knee Replacement

In a stable patient with prior ischemic stroke (>3 months ago) undergoing total knee arthroplasty, aspirin should be stopped 7 days before surgery and restarted within 24 hours postoperatively once adequate hemostasis is achieved, as the cardiovascular mortality risk from aspirin discontinuation substantially outweighs surgical bleeding risk in this high-risk population. 1, 2

Preoperative Aspirin Discontinuation Timeline

Stop aspirin 7 days (one week) before the scheduled total knee replacement. 1 This timing allows for:

• Complete platelet turnover, as aspirin irreversibly inhibits platelet cyclooxygenase for the lifespan of the platelet (7-10 days) 3
• Normalization of platelet function before the high bleeding-risk orthopedic procedure 1

The one-week discontinuation window is specifically recommended by the NCCN guidelines for surgical procedures where bleeding risk must be minimized. 1

Critical Risk Assessment: Why Continuation May Be Considered

For patients with recent ischemic stroke (<3 months), the thrombotic risk may outweigh bleeding concerns, and aspirin continuation should be strongly considered in consultation with neurology and orthopedic surgery. 2, 3 Evidence demonstrates:

• Aspirin interruption is associated with a 3-fold increased risk of cardiovascular or cerebrovascular events 4
• 70% of cardiovascular events after aspirin interruption occur within 7-10 days of discontinuation 4
• The time interval between aspirin discontinuation and acute cerebral events averages 14.3 ± 11.3 days 3
• Aspirin withdrawal precedes up to 10.2% of acute cardiovascular syndromes 3

Postoperative Aspirin Resumption

Restart aspirin within 24 hours after surgery once the surgeon confirms adequate hemostasis and acceptable bleeding risk. 1, 2 The evidence supporting early resumption includes:

• The American College of Chest Physicians recommends aspirin be restarted as soon as possible after surgery in patients with established cardiovascular disease, typically within 24 hours 2
• For patients with coronary artery disease, prior stroke, or peripheral arterial disease, aspirin should be restarted within the first 24 hours postoperatively, as discontinuation increases the absolute risk of stroke recurrence by approximately 2% within 30 days 2
• Delayed resumption beyond 24-48 hours significantly increases thrombotic event risk without meaningful reduction in bleeding complications 2

Optimal Aspirin Dosing Strategy

Use low-dose aspirin 75-100 mg daily for long-term secondary prevention after stroke. 1, 2, 4 This dosing is supported by:

• The 2024 ESC guidelines recommend aspirin 75-100 mg daily for chronic coronary syndromes and peripheral arterial disease 1
• Low-dose aspirin (75-100 mg) is as effective as higher doses for long-term treatment while minimizing gastrointestinal toxicity 4, 5
• Doses above 100 mg do not provide additional cardiovascular benefit but increase bleeding risk 4

Mandatory Gastroprotection

Add a proton pump inhibitor (PPI) for all patients with prior stroke on aspirin therapy, particularly those with additional bleeding risk factors. 4 Risk factors requiring PPI co-therapy include:

• Age >60 years 4
• History of gastrointestinal bleeding 4
• Concurrent anticoagulation or other antiplatelet agents 4
• Renal failure or severe liver disease 4

The European Heart Journal recommends gastric protection with PPIs for as long as any antithrombotic therapy is administered in patients at increased risk of GI bleeding. 4

Special Considerations for High-Risk Scenarios

If the patient is on dual antiplatelet therapy (DAPT) for recent coronary stenting, aspirin should ideally be continued throughout the perioperative period, with only the P2Y12 inhibitor temporarily held. 2 The evidence shows:

• In patients with coronary stents who required aspirin interruption, aspirin should be restarted immediately postoperatively and the P2Y12 inhibitor resumed as soon as possible due to high thrombotic risk 2
• Patients with coronary stents who discontinue aspirin have a nearly 7-fold increase in risk for death or acute cardiovascular events 4

For patients with symptomatic carotid stenosis who underwent recent stroke, DAPT with aspirin and clopidogrel is recommended for at least 3 months. 1 In these patients:

• Those undergoing surgical procedures can stop clopidogrel after surgery but should maintain aspirin 1
• The combination of aspirin and clopidogrel in the early phase of symptomatic carotid stenosis reduces stroke recurrence 1

Common Pitfalls to Avoid

Do not discontinue aspirin indefinitely or delay resumption beyond 24-48 hours without compelling bleeding concerns. 2, 4 Thrombotic events cluster early after discontinuation, with the highest risk in the first 30 days. 4

Do not restart aspirin at higher doses (>100 mg) after surgery. 4 This increases bleeding risk without improving cardiovascular outcomes. 4

Do not combine omeprazole or esomeprazole with clopidogrel if dual antiplatelet therapy is needed. 4 These PPIs inhibit CYP2C19 and reduce clopidogrel's active metabolite, compromising its efficacy. 4

Do not reflexively continue aspirin in patients taking it only for primary prevention (no established cardiovascular disease). 2 For primary prevention patients undergoing non-cardiac surgery, perioperative discontinuation is acceptable and routine postoperative restart is not required. 2

Algorithm for Decision-Making

1. Confirm indication: Is aspirin for secondary prevention after ischemic stroke? (Yes → proceed with algorithm)
2. Assess stroke timing: Is stroke >3 months old and patient neurologically stable? (Yes → 7-day preoperative discontinuation; No → consider continuing aspirin with surgical team consultation)
3. Check for coronary stents: Recent stent placement (<12 months)? (Yes → strongly consider continuing aspirin; No → proceed with 7-day discontinuation)
4. Evaluate bleeding risk factors: Age >60, prior GI bleeding, renal failure, concurrent anticoagulation? (Yes → ensure PPI prescribed)
5. Stop aspirin 7 days before surgery 1
6. Restart aspirin within 24 hours postoperatively once hemostasis confirmed 1, 2
7. Resume at 75-100 mg daily with PPI 1, 2, 4