What is the optimal timing for coronary artery bypass grafting (CABG) after acute coronary syndrome (ACS)?

Optimal Timing for CABG After Acute Coronary Syndrome

For most patients with 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 and Clinical Status

Emergency CABG (Immediate/Within Hours)

• Emergency CABG is recommended only in specific high-risk scenarios 2, 1:
  • Left main and/or 3-vessel CAD with ongoing ischemia
  • Failed PCI with ongoing ischemia or threatened occlusion
  • Coronary anatomy not amenable to PCI
  • Mechanical complications of STEMI (ventricular septal rupture, papillary muscle rupture)
  • Cardiogenic shock with anatomy unsuitable for PCI

Urgent CABG (24-72 Hours)

• Consider for high-risk coronary anatomy (left main, 3-vessel disease) with recurrent ischemia despite medical therapy 2, 1
• For patients with NSTE-ACS requiring CABG, surgery is typically performed at a median time of 73 hours after admission 1

Delayed CABG (Optimal Timing)

• Mortality rates vary significantly based on timing after STEMI 2, 1:
  • 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
• For stable patients with NSTE-ACS, delaying CABG for 3-5 days after discontinuation of P2Y12 inhibitors is recommended to reduce bleeding risk 2, 1
• CABG within 10 days after AMI is associated with significantly increased mortality, especially in elderly patients or those with severely impaired LVEF 3

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 1:
  • Clopidogrel and ticagrelor: at least 5 days before surgery
  • Prasugrel: at least 7 days before surgery
• For urgent CABG, clopidogrel and ticagrelor should be discontinued for at least 24 hours to reduce major bleeding 1, 4
• In ACS patients requiring urgent CABG, the risk of proceeding with surgery without delay for a clopidogrel-free period may be acceptable 4

Special Considerations for High-Risk Patients

• Elderly patients (>70 years) have significantly higher mortality when CABG is performed early after AMI 3:

  • <6 hours: 26.3% mortality
  • 6 hours-1 day: 14.3% mortality
  • 2-3 days: 11.9% mortality
  • 4-10 days: 6.1% mortality
  • 11-20 days: 4.2% mortality
  • 21-30 days: 3.1% mortality

• Patients with severely impaired LVEF (<30%) also have higher mortality with early CABG 3:

  • <6 hours: 27.4% mortality
  • 6 hours-1 day: 15.4% mortality
  • 2-3 days: 11.7% mortality
  • 4-10 days: 6.0% mortality
  • 11-20 days: 3.7% mortality
  • 21-30 days: 2.8% mortality

Surgical Strategy Considerations

• Off-pump CABG (OPCAB) may offer mortality benefit in ACS patients, particularly those with acute myocardial infarction 5
• For ACS cases, especially unstable angina with left main disease, where symptoms and hemodynamics are stabilized with medical therapy including IABP, emergency surgery can be avoided 6
• Complete revascularization is associated with improved long-term outcomes in ACS patients 7, 6

Common Pitfalls to Avoid

• Performing CABG within 24 hours after discontinuation of P2Y12 inhibitors significantly increases bleeding risk 1, 4
• The critical time period of 2-3 days after AMI should be avoided whenever hemodynamics are stable enough, as this period shows particularly high mortality 3
• Delaying CABG unnecessarily in patients with ongoing ischemia or hemodynamic instability can increase mortality 2, 1
• Failing to achieve complete revascularization may compromise long-term outcomes 7, 6