When to Resume DAPT After CABG in Post-ACS Patients
Resume P2Y12 inhibitor therapy as soon as it is deemed safe after CABG surgery to complete a total of 12 months of DAPT from the time of the ACS event. 1, 2
Timing of Resumption
P2Y12 inhibitor therapy should be restarted postoperatively as soon as bleeding is adequately controlled, typically within 24-48 hours after surgery when chest tube drainage is no longer significant. 1, 3
The goal is to resume DAPT promptly after CABG to ensure the full 12-month duration of therapy is completed from the initial ACS event, not from the time of surgery. 1, 2
Aspirin should be continued throughout the perioperative period at a low daily dose (75-100 mg) and should not be discontinued. 1
Standard 12-Month Duration
All post-ACS patients who undergo CABG require completion of 12 months of DAPT, regardless of whether they received prior stent implantation or were managed with medical therapy alone. 1, 2
This 12-month recommendation applies to patients with unstable angina, NSTEMI, and STEMI who subsequently undergo CABG. 1, 2
The Heart Team should estimate individual bleeding and ischemic risks to guide the timing of CABG and antithrombotic management decisions. 1
Choice of P2Y12 Inhibitor Post-CABG
Ticagrelor or prasugrel are preferred over clopidogrel for maintenance P2Y12 inhibitor therapy in post-ACS patients after CABG, provided there are no contraindications. 1, 2
Prasugrel should not be used in patients with prior stroke or TIA due to increased risk of intracranial hemorrhage. 1, 2, 4
Post-hoc analyses from major trials suggest that ticagrelor was associated with significantly reduced cardiovascular mortality compared to clopidogrel in CABG patients (approximately 50% reduction), while prasugrel showed lower 30-day mortality. 1, 3
Modified Duration for High Bleeding Risk
In CABG patients with prior MI who are at high risk of severe bleeding (e.g., PRECISE-DAPT score ≥25), discontinuation of P2Y12 inhibitor therapy after 6 months should be considered. 1
Patients who develop high bleeding risk, require oral anticoagulation, face major intracranial surgery, or experience significant overt bleeding may reasonably discontinue P2Y12 therapy after 6 months. 1
Extended DAPT Beyond 12 Months
In patients perceived to be at high ischemic risk with prior MI and CABG who have tolerated DAPT without bleeding complications, continuation of DAPT for longer than 12 months and up to 36 months may be considered. 1
This extended duration is a Class IIb recommendation and should only be considered in carefully selected patients without high bleeding risk. 1
Preoperative Management Context
Before non-emergent CABG, P2Y12 inhibitors should be discontinued: at least 3 days for ticagrelor, at least 5 days for clopidogrel, and at least 7 days for prasugrel. 1, 2, 4
However, aspirin should be continued throughout the perioperative period. 1
Critical Pitfalls to Avoid
Do not fail to resume P2Y12 inhibitor therapy postoperatively in ACS patients, as this significantly increases the risk of subsequent cardiovascular events. 2, 4
Do not prematurely discontinue DAPT within the first 12 months after ACS without compelling bleeding-related reasons. 2
Do not use prasugrel in patients with history of stroke or TIA, as this is an absolute contraindication. 1, 2, 4
Do not delay resumption beyond 48-72 hours unless there are ongoing bleeding concerns, as ischemic risk increases with delayed reinitiation. 3