Should Plavix (clopidogrel) be held in a patient undergoing an angiogram?

Management of Plavix (Clopidogrel) for Patients Undergoing Angiogram

Plavix (clopidogrel) should not be discontinued prior to a diagnostic angiogram, as there is no evidence supporting the need to hold this medication before this procedure.

Understanding the Evidence

The guidelines provide clear direction regarding antiplatelet management in patients undergoing coronary procedures:

• The 2011 ACC/AHA guidelines for unstable angina/NSTEMI management specifically recommend continuing antiplatelet therapy, including clopidogrel, when patients undergo diagnostic angiography 1.
• For patients who are already on clopidogrel therapy and are scheduled for angiography, the guidelines support maintaining this medication through the perioperative period 1.
• The guidelines differentiate between diagnostic angiography and surgical procedures like CABG, with the latter requiring discontinuation of clopidogrel 5-7 days before surgery 1.

Clinical Decision Algorithm

For Diagnostic Angiography:

1. Continue clopidogrel without interruption
   • Maintain regular dosing schedule
   • No need to hold doses before the procedure
   • Continue aspirin therapy as well

Special Considerations:

If angiography may lead to immediate CABG:

• In patients with high likelihood of needing urgent CABG following angiography:
  • Consider risk-benefit assessment
  • The ACC/AHA guidelines note that clopidogrel should be withheld for 5-7 days before CABG 1
  • However, this consideration applies only when CABG is planned or highly likely, not for routine diagnostic angiography

If angiography may lead to PCI:

• Continue clopidogrel therapy
• For clopidogrel-naïve patients who may need PCI, guidelines recommend administering a loading dose before the procedure 1
• For patients already on maintenance therapy, continue regular dosing

Rationale and Evidence Strength

The recommendation to continue clopidogrel during angiography is based on:

1. Procedural safety: Diagnostic angiography has a low bleeding risk even with continued antiplatelet therapy
2. Thrombotic protection: Discontinuing antiplatelet therapy may increase risk of thrombotic events
3. Procedural flexibility: If PCI becomes necessary during the same procedure, patients already have appropriate antiplatelet coverage

Common Pitfalls to Avoid

1. Confusing angiography with CABG requirements: While CABG requires holding clopidogrel for 5-7 days, diagnostic angiography does not
2. Unnecessary discontinuation: Stopping clopidogrel before angiography may expose patients to unnecessary thrombotic risk
3. Inadequate preparation for possible PCI: If PCI might follow angiography, maintaining antiplatelet therapy is crucial

Conclusion

Based on current guidelines, clopidogrel should be continued in patients undergoing diagnostic coronary angiography. The only exception would be in cases where there is a very high likelihood of proceeding directly to CABG, in which case an individualized risk assessment should be performed in consultation with the cardiac surgery team.