What is the recommended duration of Dual Antiplatelet Therapy (DAPT) for the medical management of Non-ST-Elevation Myocardial Infarction (NSTEMI)?

DAPT Duration for Medical Management of NSTEMI

For NSTEMI patients managed with medical therapy alone (without revascularization), dual antiplatelet therapy with aspirin plus a P2Y12 inhibitor should be continued for at least 12 months. 1

Standard DAPT Regimen

Aspirin dosing:

• Use 81 mg daily (acceptable range 75-100 mg) as the aspirin component of DAPT 1, 2

P2Y12 inhibitor options:

• Ticagrelor is preferred over clopidogrel for maintenance P2Y12 inhibitor therapy in NSTE-ACS patients managed medically (Class IIa recommendation) 1, 2
• Clopidogrel is an acceptable alternative if ticagrelor is not tolerated or contraindicated 1
• Prasugrel is reasonable in patients without high bleeding risk and no history of stroke or TIA 1, 2
• Never use prasugrel in patients with prior stroke or TIA due to increased bleeding risk (Class III: Harm) 1, 2

Minimum Duration Requirements

The 12-month minimum duration is based on the CURE trial, which demonstrated a 2.1% absolute reduction in ischemic events with clopidogrel plus aspirin versus aspirin alone in NSTE-ACS patients, though this came with a 1.0% absolute increase in major bleeding 1. This benefit was observed in both revascularized and medically managed patients 1.

Extended DAPT Beyond 12 Months

Consider continuation beyond 12 months if:

• Patient has tolerated DAPT without bleeding complications 1, 2
• Patient is not at high bleeding risk (no prior bleeding on DAPT, no coagulopathy, no oral anticoagulant use) 1, 2
• This is a Class IIb recommendation (may be reasonable) 1

The tradeoff with extended DAPT:

• Extended DAPT (18-36 months) reduces ischemic events by 1-3% absolute risk 1
• But increases bleeding complications by approximately 1% absolute risk 1
• Greatest benefit occurs when P2Y12 inhibitor therapy has not been discontinued or was discontinued ≤30 days 1

Shortened DAPT Duration (High Bleeding Risk)

Discontinuation after 6 months may be reasonable if: 1, 2

• Patient develops high bleeding risk (e.g., requires oral anticoagulation)
• Patient is at high risk of severe bleeding complications (e.g., major intracranial surgery planned)
• Patient develops significant overt bleeding
• This is a Class IIb recommendation 1

Critical Clinical Pitfalls

Avoid these common errors:

• Do not stop DAPT prematurely within the first 12 months without compelling bleeding or surgical reasons 2
• Do not use prasugrel in patients with prior stroke or TIA 1, 2
• Do not use aspirin doses higher than 100 mg daily during DAPT, as this increases bleeding without improving efficacy 1, 2
• Do not discontinue all antiplatelet therapy after completing DAPT—transition to lifelong single antiplatelet therapy (aspirin or clopidogrel) 3

Special Circumstance: If CABG Required

If the medically managed NSTEMI patient subsequently requires CABG:

• Resume P2Y12 inhibitor therapy after surgery to complete the full 12 months of DAPT from the time of the ACS event 1
• This is a Class I recommendation 1

Evidence Quality Note

The 12-month duration recommendation is supported by multiple landmark trials (CURE, PLATO, TRITON-TIMI 38) and represents the strongest level of evidence available 1. Recent observational data from EPICOR Asia showed that NSTEMI patients who stopped DAPT early (≤12 months) had higher composite event rates (10.6% vs 3.1%) and mortality (8.4% vs 1.6%) compared to those continuing beyond 12 months, though causality cannot be inferred from this observational study 4.