What are the implications of discontinuing Dual Antiplatelet Therapy (DAPT) before a drug-eluting stent placement in a patient undergoing Radial Artery Catheterization (RICA)?

From the Guidelines

Dual antiplatelet therapy (DAPT) should not be discontinued before a right internal carotid artery (RICA) stent procedure, as it significantly increases the risk of stent thrombosis, which can lead to stroke or death 1.

Recommendation

The most recent and highest quality study, the 2024 ESC guidelines for the management of chronic coronary syndromes, recommends DAPT consisting of aspirin 75–100 mg and clopidogrel 75 mg daily for up to 6 months after PCI-stenting in patients with no indication for oral anticoagulation 1.

• DAPT should be initiated at least 5-7 days before the procedure, with a loading dose of clopidogrel 300-600 mg if urgent intervention is needed.
• After stent placement, DAPT should be continued for at least 1-3 months, followed by single antiplatelet therapy (typically aspirin) indefinitely.
• Premature discontinuation of DAPT can lead to stroke or death, and any consideration of DAPT interruption should involve consultation between the interventionalist, surgeon, and anesthesiologist to balance bleeding and thrombotic risks.

Considerations

• The antiplatelet effect prevents platelet aggregation on the stent surface during endothelialization.
• If surgery is required during this period, aspirin should be continued if possible, and the P2Y12 inhibitor resumed as soon as hemostasis is achieved.
• In patients at high bleeding risk but not at high ischemic risk, it is recommended to discontinue DAPT 1–3 months after PCI and to continue with single antiplatelet therapy 1.
• Stopping DAPT after 1–3 months from PCI-stenting may be considered in patients who are not at high bleeding risk nor at high risk of ischemic events 1.

From the FDA Drug Label

As shown in Figure 3, discontinuation of cangrelor infusion, followed by administration of the irreversible P2Y12 platelet inhibitors clopidogrel or prasugrel led to a 1-hour decrease in IPA followed by an increase in inhibition of platelet aggregation beginning at about one hour After discontinuation of the infusion, the anti-platelet effect decreases rapidly and platelet function returns to normal within 1 hour.

The anti-platelet effect of cangrelor decreases rapidly after discontinuation of the infusion, with platelet function returning to normal within 1 hour. When transitioning to other oral P2Y12 platelet inhibitors like clopidogrel or prasugrel after discontinuing cangrelor, there is a decrease in platelet inhibition for about 1 hour before the effect of the new medication begins. In contrast, administering ticagrelor during the cangrelor infusion does not significantly attenuate the anti-platelet effect of ticagrelor after cangrelor is discontinued 2.

From the Research

Discontinuing DAPT before RICA Stent

• The decision to discontinue Dual Antiplatelet Therapy (DAPT) before a RICA stent procedure should be based on individual patient characteristics, including the risk of bleeding and myocardial ischemia 3.
• Current guidelines recommend a duration of DAPT with aspirin and oral P2Y12 receptor inhibitors following percutaneous coronary intervention (PCI) with second-generation drug-eluting stents (DES) of 6 months for most patients with stable coronary disease and of 12 months for most patients with acute coronary syndromes 4.
• A study found that preoperative cessation of both dual anti-platelet agents is safe after 1 year in patients receiving percutaneous coronary intervention, with no significant difference in major adverse cardiovascular events (MACE) between the discontinuation and continuation groups 5.
• The choice of P2Y12 receptor antagonist among clopidogrel, prasugrel, or ticagrelor on top of aspirin (ASA) for DAPT in patients after acute coronary syndromes (ACS) should consider the comparative risks of gastrointestinal (GI) adverse events, with clopidogrel being safer than ticagrelor, but prasugrel data being lacking or inconclusive 6.
• Recommendations for the duration of DAPT after PCI should consider patient-specific risk, clinical presentation, stent characteristics, and procedural factors, with prolonged DAPT resulting in a reduction of stent thrombosis (ST) and myocardial infarction (MI) at the cost of increased bleeding 7.