When to hold Plavix (clopidogrel) and aspirin prior to cardiac catheterization?

Management of Plavix and Aspirin Prior to Cardiac Catheterization

Do not routinely hold aspirin before cardiac catheterization, and withhold clopidogrel (Plavix) only if diagnostic catheterization is planned within 24-36 hours AND urgent CABG cannot be excluded based on clinical presentation. 1

Aspirin Management

• Continue aspirin through cardiac catheterization - aspirin should not be discontinued and should be given indefinitely to all patients with acute coronary syndromes unless there is a true aspirin allergy 1
• Aspirin is a cornerstone of ACS management and should be maintained regardless of the reperfusion strategy employed 1
• The bleeding risk from continuing aspirin during catheterization is substantially lower than the thrombotic risk from withdrawal 2

Clopidogrel (Plavix) Management - Decision Algorithm

For Unstable Patients or Known ACS:

• Administer clopidogrel immediately - do not withhold even if catheterization is imminent 1
• Unstable patients should receive clopidogrel (or ticagrelor) or be taken for immediate angiography 1
• The ischemic benefit outweighs bleeding risk in this population 3

For Stable Patients with Planned Catheterization Within 24-36 Hours:

• Withhold clopidogrel until coronary anatomy is defined if urgent CABG cannot be excluded based on clinical presentation 1
• This approach is reasonable when diagnostic catheterization is planned within 24-36 hours after presentation 1
• The loading dose can be administered in the catheterization laboratory prior to PCI or immediately after catheterization if CABG is not needed 1

For Patients with Deferred Catheterization (>24-36 hours):

• Start clopidogrel immediately - the waiting period justifies early antiplatelet therapy to prevent ischemic events 1
• Clopidogrel should be administered when catheterization will be deferred for 24-36 hours 1

If CABG Becomes Necessary

• Discontinue clopidogrel for 5 days minimum, preferably 7 days before elective CABG 1, 4
• Clopidogrel is an irreversible inhibitor of platelet function, requiring this washout period for adequate platelet recovery 1, 4
• However, experienced surgeons may proceed with "early" CABG (within 5 days of clopidogrel) at acceptable incremental bleeding risk in urgent situations 1

Evidence on Early CABG After Clopidogrel:

• In the CRUSADE Registry, 30% of UA/NSTEMI patients underwent CABG while on acute clopidogrel therapy 1
• Early CABG after clopidogrel was associated with increased blood transfusion requirements but no difference in mortality, reinfarction, or stroke rates 1
• Upstream clopidogrel administration in NSTE-ACS patients requiring CABG was associated with significantly fewer 30-day ischemic events without significantly increasing major bleeding 3

Critical Pitfalls to Avoid

• Never discontinue aspirin before catheterization unless there is active bleeding or true allergy - the thrombotic risk far exceeds bleeding risk 1, 2
• Do not withhold clopidogrel in unstable ACS patients out of concern for potential CABG - the ischemic risk during the waiting period is substantial 1, 3
• Avoid bridging with heparin as a substitute for antiplatelet therapy - this does not provide protection against coronary artery or stent thrombosis 2
• Resume clopidogrel within 12-24 hours post-procedure if CABG is not performed, as discontinuation increases cardiovascular event risk 4, 5

Special Considerations for Patients Already on Clopidogrel

• If the patient is already taking clopidogrel for a recent stent (especially drug-eluting stent within 12 months), do not discontinue - premature withdrawal is associated with a 10% risk of vascular events and potentially fatal stent thrombosis 6
• For patients with drug-eluting stents placed within the prior year, cardiology consultation is essential before any clopidogrel interruption 7