What is the best time to perform Coronary Artery Bypass Grafting (CABG) after an Acute Coronary Syndrome (ACS)?

Optimal Timing for CABG After Acute Coronary Syndrome

For patients with Acute Coronary Syndrome (ACS), CABG should be delayed 4-7 days after the event when possible, as mortality rates are significantly lower compared to earlier surgery. 1

Timing Recommendations Based on ACS Type

STEMI Patients

• Emergency CABG is recommended only in specific scenarios: left main/3-vessel disease, ongoing ischemia after failed PCI, coronary anatomy not amenable to PCI, mechanical complications of STEMI, or cardiogenic shock 1
• Mortality rates vary significantly based on timing after STEMI:
  • Within 6 hours: 10.8% mortality
  • 7-24 hours: 23.8% mortality
  • 1-3 days: 6.7% mortality
  • 4-7 days: 4.2% mortality
  • After 8 days: 2.4% mortality 1

NSTEMI/Unstable Angina Patients

• For patients with NSTE-ACS requiring CABG, surgery is typically performed at a median time of 73 hours after admission 1
• In-hospital mortality for NSTEMI patients undergoing CABG is approximately 3.7% 1
• For stable patients with NSTE-ACS, delaying CABG for 3-5 days after discontinuation of P2Y12 inhibitors is recommended to reduce bleeding risk 1

Antiplatelet Management Before CABG

• Aspirin (81-325 mg daily) should be continued preoperatively for all patients undergoing CABG 1
• P2Y12 inhibitors should be discontinued before elective CABG:
  • Clopidogrel and ticagrelor: at least 5 days before surgery 1, 2
  • Prasugrel: at least 7 days before surgery 1, 2
• For urgent CABG, clopidogrel and ticagrelor should be discontinued for at least 24 hours to reduce major bleeding 1
• Short-acting IV GP IIb/IIIa inhibitors should be discontinued 2-4 hours before surgery (eptifibatide/tirofiban) or 12 hours before surgery (abciximab) 1

Special Considerations

High-Risk Patients

• Elderly patients (>70 years) and those with severely impaired left ventricular function (LVEF <30%) have significantly higher mortality with early CABG after ACS 3
• Mortality rates in patients >70 years based on timing after AMI:
  • <6 hours: 26.3%
  • 6 hours-1 day: 14.3%
  • 2-3 days: 11.9%
  • 4-10 days: 6.1%
  • 11-20 days: 4.2%
  • 21-30 days: 3.1% 3

Urgent vs. Emergency CABG

• When possible, stabilizing ACS patients with medical therapy (including IABP) and performing urgent rather than emergency CABG may improve outcomes 4, 5
• Complete revascularization is more likely with urgent CABG (3.1 distal anastomoses) compared to emergency CABG (2.5 distal anastomoses) 4

Algorithm for CABG Timing After ACS

1. Immediate CABG (within hours) only for:

   • Cardiogenic shock with anatomy unsuitable for PCI 1, 6
   • Failed PCI with ongoing ischemia 1
   • Left main or complex multivessel disease with hemodynamic instability 1, 6

2. Delay CABG 4-7 days when possible for:

   • Stable patients with NSTEMI/UA 1, 3
   • Patients on P2Y12 inhibitors (to allow washout period) 1, 2
   • Elderly patients or those with poor LV function 3

3. Delay CABG 3-5 days after discontinuation of P2Y12 inhibitors for:

   • Patients on dual antiplatelet therapy without urgent indications 1

4. Consider urgent CABG (24-72 hours) for:

   • High-risk coronary anatomy (left main, 3-vessel disease) 1, 6
   • Recurrent ischemia despite medical therapy 1, 7

Common Pitfalls to Avoid

• Performing CABG within 24 hours after discontinuation of P2Y12 inhibitors significantly increases bleeding risk 1
• The critical time period of 2-3 days after ACS should be avoided whenever possible due to higher mortality rates 3
• Delaying CABG beyond 7 days in unstable patients may increase risk of recurrent ischemic events 7, 8
• Failing to consider complete revascularization in urgent settings may compromise long-term outcomes 4, 5