What are the guidelines for anti-platelet therapy post Percutaneous Transluminal Coronary Angioplasty (PTCA)?

Antiplatelet Therapy Guidelines Post-PTCA

For patients undergoing PCI in chronic coronary syndrome without indication for oral anticoagulation, dual antiplatelet therapy (DAPT) with aspirin 75-100 mg plus clopidogrel 75 mg daily for up to 6 months is the recommended default strategy, followed by lifelong single antiplatelet therapy. 1

Initial DAPT Strategy

Standard Chronic Coronary Syndrome (CCS) Patients

• Initiate DAPT immediately post-PCI with aspirin 75-100 mg daily plus clopidogrel 75 mg daily (after appropriate loading dose of 600 mg or >5 days maintenance therapy) 1
• Continue DAPT for up to 6 months as the default duration for CCS patients with drug-eluting stents 1
• After 6 months, transition to lifelong single antiplatelet therapy with either aspirin 75-100 mg daily OR clopidogrel 75 mg daily 1

Acute Coronary Syndrome (ACS) Patients

• DAPT must continue for at least 12 months in all ACS patients treated with PCI, regardless of stent type 2, 3
• Consider more potent P2Y12 inhibitors (prasugrel 10 mg daily or ticagrelor 90 mg twice daily) instead of clopidogrel for ACS patients, as they provide superior outcomes 3
• Prasugrel is contraindicated in patients with prior stroke/TIA and generally not recommended in patients ≥75 years old or <60 kg body weight due to increased bleeding risk 4

Shortened DAPT Duration (High Bleeding Risk)

For patients at high bleeding risk but not at high ischemic risk, discontinue DAPT after 1-3 months and continue single antiplatelet therapy. 1

• High bleeding risk is traditionally defined as ≥4% annual risk of serious bleeding or ≥1% risk of intracranial hemorrhage 3
• Risk factors include: age ≥65 years, body weight <60 kg, diabetes, prior bleeding history, or concomitant oral anticoagulation 3
• Stopping DAPT after 1-3 months may be considered even in patients not at high bleeding risk nor high ischemic risk 1

Extended DAPT Duration (High Ischemic Risk)

• In patients at enhanced ischemic risk without high bleeding risk, consider adding a second antithrombotic agent to aspirin for extended long-term secondary prevention 1
• For ACS patients who tolerated DAPT without bleeding complications and are not at high bleeding risk, continuation beyond 12 months may be reasonable 2

Choice of Single Antiplatelet Therapy After DAPT

Clopidogrel 75 mg daily is recommended as a safe and effective alternative to aspirin monotherapy for long-term therapy after the initial DAPT period. 1

• Both aspirin 75-100 mg daily and clopidogrel 75 mg daily are equally acceptable options for lifelong therapy 1
• Emerging evidence suggests P2Y12 inhibitor monotherapy (clopidogrel or ticagrelor) may be superior to aspirin monotherapy after completing initial DAPT, with potentially lower bleeding rates 5, 6, 7

Special Populations

Patients Requiring Oral Anticoagulation

After uncomplicated PCI in CCS patients with concomitant indication for oral anticoagulation, early cessation of aspirin (≤1 week) followed by continuation of oral anticoagulation plus clopidogrel is recommended. 1

• Continue dual therapy (oral anticoagulation + clopidogrel) for up to 6 months in patients not at high ischemic risk 1
• Continue dual therapy for up to 12 months in patients at high ischemic risk 1
• After dual therapy period, transition to oral anticoagulation alone 1
• Direct oral anticoagulants (DOACs) are preferred over warfarin when eligible 1

High-Thrombotic Risk Stenting

• For complex left main stem, 2-stent bifurcation, suboptimal stenting result, or prior stent thrombosis, prasugrel or ticagrelor may be considered instead of clopidogrel for the first month and up to 3-6 months 1

Post-CABG Patients

• Resume P2Y12 inhibitor therapy after CABG in ACS patients to complete 12 months of DAPT 2
• When non-emergent cardiac surgery is needed, postpone surgery at least 3 days after ticagrelor, 5 days after clopidogrel, and 7 days after prasugrel discontinuation 2

Critical Pitfalls to Avoid

Premature discontinuation of DAPT significantly increases the risk of stent thrombosis, particularly within the first month after stent implantation, which carries 20-40% mortality. 2, 8

• Never discontinue DAPT without discussing with the interventional cardiologist, especially in the first few weeks after ACS 1, 2
• If bleeding occurs, attempt to manage bleeding without discontinuing antiplatelet therapy when possible 4
• Add proton pump inhibitor for gastrointestinal protection (avoid omeprazole/esomeprazole with clopidogrel due to CYP2C19 interaction) 1
• Use radial access when possible during PCI to minimize bleeding complications 1

Procedural Considerations

• Aspirin loading dose of 162-325 mg should be administered prior to catheterization in ACS patients 1
• P2Y12 inhibitor loading dose should be administered in the periprocedural period (clopidogrel 600 mg is standard) 1
• For CCS patients undergoing high-thrombotic risk stenting with known CYP2C19 *2/*3 polymorphisms, consider increasing clopidogrel dose to 150 mg daily if <50% platelet aggregation inhibition is demonstrated 1