What are the recommendations for Dual Antiplatelet Therapy (DAPT) in a patient with Non-ST-Elevation Myocardial Infarction (NSTEMI) who has undergone Coronary Artery Bypass Grafting (CABG)?

DAPT Recommendations for NSTEMI Patients After CABG

In patients with NSTEMI who undergo CABG, P2Y12 inhibitor therapy should be resumed postoperatively as soon as deemed safe and continued to complete 12 months of DAPT therapy from the time of the acute coronary syndrome event. 1, 2

Core Recommendation

• Resume P2Y12 inhibitor therapy postoperatively to complete a full 12 months of DAPT after the NSTEMI event, regardless of when CABG occurred during that timeframe (Class I, Level C-LD recommendation). 1

• Aspirin 75-100 mg daily should be continued throughout the perioperative period and indefinitely thereafter (Class I, Level B-NR recommendation). 1, 2

Timing of P2Y12 Inhibitor Resumption

• Resume P2Y12 inhibitor as soon as it is deemed safe postoperatively, typically within 24-48 hours when hemostasis is secured and bleeding risk is controlled. 1, 2

• The Heart Team should estimate individual bleeding and ischemic risks to guide the timing of resumption (Class I, Level C recommendation). 1

Choice of P2Y12 Inhibitor

• Clopidogrel 75 mg daily is the most studied and appropriate agent for most CABG patients. 2, 3

• Ticagrelor may be preferred over clopidogrel in ACS patients, as post-hoc analysis from the PLATO study demonstrated significant reduction in cardiovascular mortality compared to clopidogrel in patients who underwent CABG, though with similar overall primary endpoints. 1, 2

• Prasugrel showed significantly lower 30-day mortality than clopidogrel in CABG patients from TRITON-TIMI 38, but with more postoperative blood loss. 1 However, prasugrel should be discontinued at least 7 days prior to surgery when possible. 4

• Potent P2Y12 inhibitors (prasugrel or ticagrelor) are generally not recommended as part of triple antithrombotic therapy when oral anticoagulation is required. 3

Duration Algorithm

For NSTEMI patients undergoing CABG:

• 0-12 months post-ACS: Aspirin 75-100 mg daily + P2Y12 inhibitor (resume postoperatively and continue to complete 12 months from ACS event). 1, 2, 3

• After 12 months: Aspirin 75-100 mg daily indefinitely (transition to single antiplatelet therapy). 2

Bleeding Risk Modifications

• High bleeding risk patients (PRECISE-DAPT ≥25): Consider discontinuation of P2Y12 inhibitor after 6 months in CABG patients with prior MI (Class IIa, Level C recommendation). 1

• Add proton pump inhibitor (PPI) in patients at increased risk of gastrointestinal bleeding, including elderly patients, those with history of GI bleeding, chronic NSAID use, or combination antithrombotic therapy. 2, 3

• Patients with increased bleeding risk (e.g., oral anticoagulation, major intracranial surgery, or significant overt bleeding) may favor shorter-than-recommended DAPT duration, but this must be balanced against ischemic risk in the ACS setting. 1, 3

Critical Evidence Supporting This Approach

• The CURE study demonstrated reduction in ischemic events in ACS patients treated with aspirin plus clopidogrel who underwent CABG, consistent with the overall study population. 1

• Danish registry data showed significantly fewer deaths during mean follow-up of 466±144 days in CABG patients treated with aspirin plus clopidogrel versus aspirin alone after ACS, though without reduction in recurrent MI. 1

• Recent meta-analysis (2024) demonstrated that DAPT compared with single antiplatelet therapy after CABG was associated with significantly lower all-cause mortality (OR 0.65,95% CI 0.50-0.86), cardiovascular mortality (OR 0.53,95% CI 0.33-0.84), and MACCE (OR 0.68,95% CI 0.51-0.91), especially in ACS patients, though with higher rates of major bleeding (OR 1.30,95% CI 1.08-1.56). 5

Common Pitfalls to Avoid

• Do not discontinue P2Y12 inhibitor prematurely after CABG in NSTEMI patients—the 12-month duration is calculated from the ACS event, not from the surgery date. 1

• Do not fail to resume P2Y12 inhibitor postoperatively—this is a Class I recommendation and critical for reducing mortality and cardiovascular events in ACS patients. 1, 2

• Avoid using potent P2Y12 inhibitors (ticagrelor/prasugrel) in triple therapy when oral anticoagulation is required—use clopidogrel instead. 3

• Do not continue aspirin at high doses—the recommended dose is 75-100 mg daily, not the higher loading doses sometimes used acutely. 1, 2