What is the recommended antiplatelet therapy regimen for patients with a history of cardiovascular events or undergoing procedures like percutaneous coronary intervention (PCI) with stenting, considering the choice between double and triple antiplatelet therapy?

Double vs Triple Antiplatelet Therapy: Clinical Recommendations

Dual antiplatelet therapy (DAPT) with aspirin plus a P2Y12 inhibitor is the standard regimen for patients undergoing PCI with stenting, while triple therapy (DAPT plus oral anticoagulation) should be reserved only for patients with concurrent indications for anticoagulation (such as atrial fibrillation) and should be minimized in duration due to significantly increased bleeding risk. 1

Standard Approach: Dual Antiplatelet Therapy (DAPT)

For Acute Coronary Syndrome (ACS) Patients

DAPT is the definitive standard of care for all ACS patients undergoing PCI, consisting of aspirin plus a potent P2Y12 inhibitor for 12 months. 2

• First-line P2Y12 inhibitor: Ticagrelor 180 mg loading dose, then 90 mg twice daily is recommended as first-line therapy for ACS patients, regardless of initial treatment strategy 1, 2
• Alternative for PCI patients: Prasugrel 60 mg loading dose, then 10 mg daily for P2Y12 inhibitor-naïve patients with NSTE-ACS or STEMI undergoing PCI, unless contraindications exist 2, 3
• When potent agents contraindicated: Clopidogrel 600 mg loading dose, then 75 mg daily for patients with prior intracranial hemorrhage or indication for oral anticoagulation 2

For Stable Coronary Artery Disease

• Drug-eluting stent (DES): Clopidogrel for at least 6 months 4
• Bare metal stent (BMS): Clopidogrel for minimum 1 month, ideally up to 12 months 4
• After completion of DAPT duration: Lifelong aspirin 75-100 mg daily 4, 5

Aspirin Dosing with DAPT

• Maintain aspirin at 75-100 mg daily when used with DAPT to minimize bleeding risk 1, 2
• After PCI, 81 mg aspirin daily is reasonable in preference to higher maintenance doses 5

Triple Therapy: When Oral Anticoagulation is Required

Triple therapy (aspirin + P2Y12 inhibitor + oral anticoagulant) should be limited to the shortest possible duration due to substantially increased bleeding risk, with dual therapy (oral anticoagulant + single antiplatelet agent) as the preferred alternative. 1

Duration Algorithm Based on Bleeding Risk

For patients with atrial fibrillation undergoing elective PCI:

• Low bleeding risk (HAS-BLED 0-2): Triple therapy for 1-3 months, followed by dual therapy (OAC + clopidogrel) until 12 months, then OAC monotherapy [1, @22@]
• High bleeding risk (HAS-BLED ≥3): Triple therapy for 1 month only, followed by dual therapy (OAC + clopidogrel) for 6 months, then OAC monotherapy [1, @23@]
• Unusually high bleeding risk: Consider OAC + clopidogrel (no aspirin) for 6 months, then OAC monotherapy [1, @24@]

For patients with atrial fibrillation presenting with ACS:

• Low bleeding risk: Triple therapy for 6 months, followed by dual therapy (OAC + clopidogrel) until 12 months, then OAC monotherapy 1
• High bleeding risk (HAS-BLED ≥3): Triple therapy for 1-3 months, followed by dual therapy (OAC + clopidogrel) up to 12 months, then OAC monotherapy [1, @25@]

Critical Specifications for Triple Therapy

• P2Y12 inhibitor choice: Clopidogrel is the ONLY recommended P2Y12 inhibitor for triple therapy; prasugrel and ticagrelor should be avoided due to excessive bleeding risk 1
• Oral anticoagulant preference: NOACs (particularly dabigatran 150 mg or 110 mg twice daily, or rivaroxaban 15 mg daily) are preferred over warfarin due to lower bleeding risk 1
• Rivaroxaban dosing: When used with antiplatelet agents, use 15 mg once daily instead of the standard 20 mg dose 1
• Warfarin management: If warfarin is used, maintain INR at the lower end of therapeutic range (2.0-2.5) 1

Bleeding Risk Mitigation Strategies

All patients on DAPT or triple therapy require proactive bleeding risk reduction measures. 1, 2

• Proton pump inhibitor (PPI): Prescribe routinely to all patients on DAPT or triple therapy to reduce gastrointestinal bleeding 1, 2
• Radial access: Use radial over femoral access for coronary angiography and PCI when performed by an expert radial operator 2
• Bleeding risk assessment: Use HAS-BLED score or PRECISE-DAPT score to stratify ongoing risk [1, @21@]

Duration Modifications Based on Bleeding Events

The occurrence of actionable bleeding while on DAPT should prompt immediate reconsideration of type and duration of therapy. 1

• For ACS patients with PRECISE-DAPT score ≥25: Consider discontinuation of P2Y12 inhibitor after 6 months instead of 12 months 1
• Discontinuation of antiplatelet treatment in patients treated with OAC should be considered at 12 months 1

Common Pitfalls to Avoid

• Never use prasugrel or ticagrelor as part of triple therapy - this dramatically increases bleeding risk without proven benefit 1
• Never continue triple therapy beyond the minimum necessary duration - bleeding risk accumulates over time 1
• Never omit PPI prescription - this simple intervention significantly reduces gastrointestinal bleeding 1, 2
• Never use prasugrel in patients with prior stroke/TIA - this is an absolute contraindication due to increased cerebrovascular bleeding risk 3
• Never discontinue DAPT prematurely within first month after stent placement - this dramatically increases stent thrombosis risk 2, 4

Surgical Considerations

• Ticagrelor: Discontinue 3 days prior to elective surgery 1
• Clopidogrel: Discontinue at least 5 days prior to surgery 4
• Prasugrel: Discontinue at least 7 days prior to surgery 4, 3
• Do not discontinue DAPT within first month for elective non-cardiac surgery 2