What is the recommended duration and regimen for dual antiplatelet therapy in a patient with a history of multivessel stent placement?

Dual Antiplatelet Therapy Duration for Multivessel Stent Placement

For patients with multivessel coronary stent placement, dual antiplatelet therapy (DAPT) should be continued for at least 12 months, with consideration for extended therapy beyond 12 months in patients who have tolerated DAPT without bleeding complications and are at low bleeding risk but high thrombotic risk.

Standard DAPT Duration Recommendations

Initial 12-Month Therapy

• In patients with acute coronary syndrome (ACS) treated with drug-eluting stent (DES) or bare metal stent (BMS) implantation, P2Y12 inhibitor therapy (clopidogrel, prasugrel, or ticagrelor) should be given for at least 12 months 1
• Daily aspirin dose of 81 mg (range 75-100 mg) is recommended in combination with the P2Y12 inhibitor 1

P2Y12 Inhibitor Selection

• For ACS patients with multivessel stenting:
  • Ticagrelor is preferred over clopidogrel (Class IIa, Level B-R) 1
  • Prasugrel is reasonable over clopidogrel in patients without high bleeding risk or history of stroke/TIA (Class IIa, Level B-R) 1
  • Clopidogrel should be used when ticagrelor or prasugrel are contraindicated 1

Extended DAPT Considerations

Extended DAPT (>12 months)

For patients with multivessel stenting, extended DAPT beyond 12 months may be reasonable (Class IIb) if:

• Patient has tolerated DAPT without bleeding complications
• Patient is not at high bleeding risk (e.g., no prior bleeding on DAPT, no coagulopathy, no oral anticoagulant use)
• Patient has high thrombotic risk factors such as:
  • Multivessel stent placement (your patient's case)
  • Diffuse multivessel disease, especially in diabetic patients
  • At least three stents implanted
  • At least three lesions treated
  • Total stented length >60 mm
  • Treatment of chronic total occlusion
  • History of STEMI 1

Shortened DAPT (<12 months)

In patients who develop high bleeding risk after DES implantation:

• Discontinuation of P2Y12 therapy after 6 months may be reasonable (Class IIb, Level C-LD) 1
• This applies to patients who:
  • Require oral anticoagulation therapy
  • Are at high risk of severe bleeding complications
  • Develop significant overt bleeding 1

Risk Assessment and Monitoring

High Thrombotic Risk Factors

• Multivessel stent placement (as in your patient's case)
• Prior stent thrombosis on adequate antiplatelet therapy
• Stenting of the last remaining patent coronary artery
• Diffuse multivessel disease, especially in diabetic patients
• Chronic kidney disease (creatinine clearance <60 mL/min)
• Complex stenting procedures 1

High Bleeding Risk Factors

• Advanced age
• Oral anticoagulant use
• Prior bleeding history
• Anemia
• Chronic alcohol use
• End-stage renal failure 1

Bleeding Mitigation Strategies

• Use low-dose aspirin (75-100 mg daily)
• Consider proton pump inhibitors in patients with history of gastrointestinal bleeding or increased risk of bleeding
• Regular monitoring for bleeding complications
• Modifying modifiable risk factors for bleeding 1

Clinical Pitfalls to Avoid

1. Premature discontinuation: Early discontinuation of DAPT (especially within first 6 months) significantly increases risk of stent thrombosis and adverse cardiac events 2
2. Failure to reassess: Bleeding and ischemic risks should be reassessed periodically during DAPT treatment
3. Inappropriate P2Y12 inhibitor selection: Prasugrel should never be administered to patients with prior history of stroke or TIA (Class III: Harm) 1
4. Inadequate patient education: Poor patient understanding about the importance of DAPT adherence can lead to premature discontinuation 2

For your patient with multivessel stent placement from 2017 who was placed on long-term DAPT, continued therapy beyond the standard 12 months is reasonable given the high thrombotic risk associated with multivessel stenting, provided they have not experienced bleeding complications and do not have high bleeding risk factors.