What are the indications for dual antiplatelet therapy (DAPT)?

Indications for Dual Antiplatelet Therapy

Dual antiplatelet therapy (DAPT) is mandatory for all patients with acute coronary syndrome (ACS)—including STEMI, NSTEMI, and unstable angina—regardless of management strategy, and for all patients undergoing percutaneous coronary intervention (PCI) with stent placement. 1, 2, 3

Primary Indications

Acute Coronary Syndrome (All Types)

• All ACS patients require DAPT for 12 months, combining aspirin with a P2Y12 inhibitor, irrespective of whether they undergo PCI, medical management alone, or coronary artery bypass grafting (CABG). 1, 2, 3
• This includes:
  • ST-elevation myocardial infarction (STEMI) managed with primary PCI, delayed PCI, or fibrinolytic therapy 2, 3
  • Non-ST-elevation myocardial infarction (NSTEMI) 2, 3
  • Unstable angina 2, 3

Percutaneous Coronary Intervention

• All patients undergoing PCI with stent placement require DAPT, regardless of clinical presentation (stable coronary artery disease or ACS). 1, 2, 4
• For stable CAD patients treated with PCI, DAPT duration is 1–6 months depending on bleeding risk, with newer-generation drug-eluting stents (DES) preferred over bare-metal stents (BMS). 1

Optimal DAPT Regimen

First-Line P2Y12 Inhibitor Selection

• Ticagrelor (180 mg loading dose, then 90 mg twice daily) plus aspirin 75–100 mg daily is the preferred first-line regimen for all ACS patients. 1, 2, 4
• Prasugrel (60 mg loading dose, then 10 mg daily) plus aspirin is recommended for P2Y12 inhibitor-naïve patients with ACS undergoing PCI, unless contraindications exist. 1, 4
• Clopidogrel (600 mg loading dose, then 75 mg daily) plus aspirin should be reserved only for patients who cannot receive ticagrelor or prasugrel due to contraindications, including prior intracranial bleeding or need for oral anticoagulation. 1, 2

Critical Contraindications

• Prasugrel is absolutely contraindicated in patients with prior stroke or transient ischemic attack (TIA) due to increased cerebrovascular bleeding risk. 1, 2
• Prasugrel requires dose adjustment (5 mg daily) or avoidance in patients ≥75 years or body weight <60 kg. 2, 4

Standard Duration: 12 Months

• The default DAPT duration is 12 months for all ACS patients who are not at high bleeding risk, regardless of ACS type, stent type, or completeness of revascularization. 1, 2, 3, 4
• Six-month DAPT duration should be considered in patients with high bleeding risk (PRECISE-DAPT score ≥25 or meeting ARC-HBR criteria). 1, 2, 4
• Extended DAPT beyond 12 months may be considered in ACS patients who have tolerated DAPT without bleeding complications, particularly those with prior stent thrombosis, peripheral artery disease, or complex PCI. 1

Bleeding Risk Mitigation Strategies

Every patient on DAPT requires the following measures to reduce bleeding complications:

• Prescribe a proton pump inhibitor (PPI) to all patients on DAPT to reduce gastrointestinal bleeding risk. 2, 3, 4
• Maintain aspirin dose at 75–100 mg daily (not higher doses) when combined with a P2Y12 inhibitor. 1, 2, 3, 4
• Use radial artery access over femoral access for coronary angiography and PCI when performed by an experienced radial operator. 2, 3, 4

Special Clinical Scenarios

Patients Requiring Oral Anticoagulation (Triple Therapy)

• Triple therapy duration should be limited to a maximum of 6 months or omitted after hospital discharge, balancing ischemic and bleeding risk. 1
• Use clopidogrel (not ticagrelor or prasugrel) as the P2Y12 inhibitor component when combining with oral anticoagulation, due to substantially lower bleeding risk. 1, 4
• Consider early transition to dual therapy (single antiplatelet agent plus anticoagulant) after 1 month in stable patients. 4

Perioperative Management

• Continue aspirin perioperatively if bleeding risk allows. 1, 3, 4
• Never discontinue DAPT within the first month after stent placement for elective non-cardiac surgery, as this dramatically increases thrombotic risk. 1, 3
• Scheduled surgery requiring P2Y12 inhibitor discontinuation should be considered after at least 1 month, irrespective of stent type, if aspirin can be maintained throughout the perioperative period. 1
• Resume full DAPT as soon as possible post-operatively. 1, 3, 4

Patients with Prior Stent Thrombosis

• Prolonged DAPT is recommended in patients with prior stent thrombosis, especially in the absence of correctable causes. 1

Stable CAD Patients Treated with CABG

• There is insufficient data to recommend DAPT in stable CAD patients treated with CABG alone (without prior PCI). 1

Common Pitfalls to Avoid

• Do not use clopidogrel as first-line therapy when ticagrelor or prasugrel are available and not contraindicated—this represents suboptimal care for ACS patients. 2
• Do not discontinue DAPT prematurely, especially within the first month after stent placement, as early interruption dramatically raises the risk of stent thrombosis, myocardial infarction, and death. 1, 2, 3
• Do not omit PPI co-prescription from DAPT, as this simple intervention significantly reduces gastrointestinal bleeding. 2, 3
• Do not administer prasugrel to patients with prior stroke or TIA, as this is an absolute contraindication. 1, 2
• Do not use higher aspirin doses (>100 mg daily) when combined with P2Y12 inhibitors, as this increases bleeding without added benefit. 1, 2, 4