What is the recommended timeframe to utilize aspirin (acetylsalicylic acid) postoperatively?

Postoperative Aspirin Timing Recommendations

Aspirin should be started within 6-48 hours after surgery and continued indefinitely for patients undergoing coronary artery bypass grafting (CABG), while for patients with established cardiovascular disease undergoing non-cardiac surgery, aspirin should be continued throughout the perioperative period without interruption. 1

For Cardiac Surgery (CABG)

Aspirin initiation should occur within 48 hours postoperatively to reduce saphenous vein graft closure, with dosing regimens of 100-325 mg daily appearing efficacious. 1 The most recent European guidelines recommend initiating aspirin post-operatively as soon as there is no concern over bleeding, without specifying an exact hour threshold. 1

• Doses higher than 162 mg/day can be continued for up to 1 year post-CABG, after which lower maintenance doses (75-162 mg daily) should be continued indefinitely. 1
• The 2023 ACC/AHA performance measures emphasize that patients should either continue aspirin through the perioperative period OR be started on aspirin within 6 hours postoperatively if not previously taking it. 1

For Non-Cardiac Surgery in Patients with Cardiovascular Disease

Aspirin should be maintained throughout the perioperative period without interruption in patients with established coronary artery disease, prior myocardial infarction, or those requiring secondary cardiovascular prevention. 2, 3, 4

• The thrombotic risk of discontinuation exceeds bleeding risk in most surgical settings. 3, 5
• The only exception is closed-space surgery (intracranial, spinal canal, or posterior chamber eye surgery), where aspirin should be stopped 7-10 days preoperatively. 3, 5, 6

For Patients with Coronary Stents

Aspirin must be maintained throughout the perioperative period whenever possible, as discontinuation significantly increases stent thrombosis risk. 2, 3

• For drug-eluting stents placed less than 6-12 months prior: maintain aspirin perioperatively; if dual antiplatelet therapy is needed, clopidogrel can be stopped 5 days before surgery and resumed postoperatively while aspirin continues. 2
• For bare-metal stents placed less than 4-6 weeks prior: maintain both aspirin and clopidogrel if emergency surgery is required. 2
• Never substitute antiplatelet agents with heparin or low-molecular-weight heparin, as these do not adequately protect against stent thrombosis. 2, 3

Dosing Considerations

• Maintenance dose: 75-162 mg daily for long-term secondary prevention. 1
• Higher initial doses (325 mg daily) may be used for 1-6 months after percutaneous coronary intervention with stent placement, depending on stent type. 1
• For patients with aspirin-exacerbated respiratory disease requiring desensitization: continued daily administration of at least 325 mg once daily is required to maintain tolerance; gaps >48 hours may lead to loss of tolerance. 1

Critical Pitfalls to Avoid

• Never discontinue both aspirin and clopidogrel simultaneously in patients with recent stent placement (within 6-12 months for drug-eluting stents or 4-6 weeks for bare-metal stents). 2, 3
• Do not delay aspirin initiation beyond 48 hours after CABG, as this increases the risk of graft occlusion. 1
• Avoid stopping aspirin in patients with established cardiovascular disease undergoing non-cardiac surgery unless the procedure involves a closed space where bleeding would be catastrophic. 3, 5
• For minor procedures (dental, dermatologic, cataract surgery), continue aspirin without interruption. 3