How many months should antiplatelet dual therapy (DAPT) be continued in patients above 75 years old?

Duration of Dual Antiplatelet Therapy in Patients Over 75 Years Old

For patients over 75 years old with acute coronary syndrome (ACS), dual antiplatelet therapy (DAPT) should be continued for 12 months, with consideration for shortening to 6 months in those with high bleeding risk. 1

Standard DAPT Duration Recommendations by Clinical Scenario

For ACS Patients (regardless of management strategy)

• Default duration: 12 months 1
• This applies to patients managed with:
  • Medical therapy alone
  • PCI (with either BMS or DES)
  • CABG
  • Fibrinolytic therapy

Special Considerations for Elderly Patients (>75 years)

• High bleeding risk patients: Consider shorter DAPT duration of 6 months 1
• Low bleeding risk patients who tolerate DAPT well: May consider extending beyond 12 months 1

Risk Stratification for Elderly Patients

High Bleeding Risk Factors (particularly important in elderly)

• Age >75 years itself is a bleeding risk factor 2
• Low body weight (BMI <18.5)
• Prior bleeding history
• Concurrent oral anticoagulation
• Coagulopathy
• Frailty
• Multiple comorbidities
• Polypharmacy

Algorithm for DAPT Duration in Elderly Patients

1. Standard recommendation: 12 months DAPT for all ACS patients
2. Assess bleeding risk at 3-6 months:
   • If high bleeding risk: Consider shortening to 6 months 1
   • If low bleeding risk and good tolerance: Continue for full 12 months
3. At 12 months, reassess:
   • If no bleeding complications and continued high ischemic risk: Consider extending beyond 12 months 1
   • Otherwise: Discontinue P2Y12 inhibitor and continue aspirin monotherapy

P2Y12 Inhibitor Selection in Elderly Patients

• Clopidogrel is the preferred P2Y12 inhibitor for patients >75 years 1, 3
• Avoid prasugrel in patients >75 years due to increased bleeding risk 1, 2
• Ticagrelor may be considered in select patients with low bleeding risk 1

Bleeding Risk Mitigation Strategies

• Use low-dose aspirin (75-100 mg daily) 1
• Consider proton pump inhibitor for gastrointestinal protection 1, 3
• Prefer radial over femoral access for any coronary procedures 1, 3
• Regular monitoring for bleeding complications
• Maintain lower therapeutic INR range if concurrent warfarin is needed 3

Common Pitfalls to Avoid

• Automatically extending DAPT beyond 12 months without assessing bleeding risk
• Prematurely discontinuing DAPT before recommended duration without clear indication
• Using prasugrel in elderly patients >75 years (contraindicated) 1, 2
• Failing to reassess bleeding risk periodically during DAPT course
• Using standard doses of antiplatelet agents in low-weight elderly patients

Management of Triple Therapy (DAPT + Anticoagulation)

For elderly patients requiring both DAPT and oral anticoagulation:

• Limit triple therapy to maximum 6 months or consider omitting after hospital discharge 1, 3
• For high bleeding risk: Consider triple therapy for 1 month, then dual therapy (OAC + clopidogrel) 3
• Always use clopidogrel as the P2Y12 inhibitor in triple therapy regimens 1, 3

By carefully balancing ischemic and bleeding risks in elderly patients, the optimal DAPT duration can be determined to maximize cardiovascular protection while minimizing potentially life-threatening bleeding complications.