How many days before an angiography should a patient stop taking aspirin (acetylsalicylic acid)?

Management of Aspirin Before Angiography

For patients undergoing angiography, aspirin should be discontinued 5 days before the procedure if the bleeding risk is high, while aspirin can be continued throughout the perioperative period for procedures with low bleeding risk.

Risk Stratification for Aspirin Management

High Bleeding Risk Procedures

• For procedures with high bleeding risk (such as neurosurgery or spinal procedures):
  • Discontinue aspirin 5 days before the procedure 1
  • This allows complete correction of platelet function inhibited by aspirin in all patients 1
  • The effect of aspirin on platelets typically disappears after 96 hours (4 days), but a 5-day washout ensures complete correction in all patients 2

Low-to-Moderate Bleeding Risk Procedures

• For procedures with low-to-moderate bleeding risk:
  • Aspirin can be continued throughout the perioperative period 1
  • This is particularly important for patients with high thrombotic risk (recent coronary stents, history of stroke, etc.)

Special Considerations

Coronary Stent Patients

• For patients with coronary stents:
  • Bare-metal stents: If possible, delay angiography for at least 4 weeks after stent placement 1
  • Drug-eluting stents: If possible, delay angiography for at least 12 months after stent placement 1
  • If angiography cannot be delayed, continue aspirin throughout the perioperative period while discontinuing P2Y12 inhibitors (clopidogrel, prasugrel, ticagrelor) 1

Dual Antiplatelet Therapy

• If the patient is on dual antiplatelet therapy:
  • Continue aspirin if possible
  • Discontinue P2Y12 inhibitors 5 days before the procedure (clopidogrel, ticagrelor) or 7 days (prasugrel) 1
  • Resume P2Y12 inhibitors as soon as adequate hemostasis is achieved 1

Thrombotic Risk Assessment

• High thrombotic risk (continue aspirin if possible):
  • Recent coronary stent placement (< 12 months for drug-eluting stents, < 1 month for bare-metal stents)
  • History of stent thrombosis
  • Recent acute coronary syndrome (< 3 months)
  • Recent stroke or TIA (< 3 months)

Bleeding Risk vs. Thrombotic Risk

• The risk of stopping aspirin should be weighed against the benefit of reducing bleeding complications 1
• Continuing aspirin perioperatively leads to approximately 1.5-fold increase in bleeding complications but does not typically increase the severity of bleeding 3
• Premature aspirin withdrawal can increase cardiovascular risk by 3-fold, with acute coronary events occurring on average 8-11 days after discontinuation 4

Post-Procedure Management

• Resume aspirin as soon as adequate hemostasis is achieved, ideally within 24 hours after the procedure 1
• For patients at high thrombotic risk, earlier resumption should be considered if surgical hemostasis is adequate

Common Pitfalls to Avoid

• Discontinuing aspirin for too long (> 7 days) increases thrombotic risk unnecessarily
• Failing to consider the patient's thrombotic risk when deciding whether to discontinue aspirin
• Not resuming aspirin promptly after the procedure when hemostasis is adequate
• Discontinuing both aspirin and P2Y12 inhibitors simultaneously in patients with recent coronary stents (increases stent thrombosis risk significantly) 1

By following these guidelines, clinicians can balance the risk of perioperative bleeding against the risk of thrombotic events when managing patients on aspirin who require angiography.