What is the appropriate next step for a 72-year-old male with worsening chest tightness, elevated serum troponin (indicating myocardial injury), normal sinus rhythm (NSR) on electrocardiogram (ECG), left ventricular ejection fraction (LVEF) of 65%, 70% stenosis of the left main coronary artery, 80% stenosis of the left anterior descending (LAD) artery, and 90% stenosis of the right coronary artery (RCA)?

Management of Triple-Vessel Disease with Left Main Coronary Artery Stenosis

Coronary artery bypass grafting (CABG) is the recommended next step for this 72-year-old male with significant left main coronary artery stenosis (70%), LAD stenosis (80%), and RCA stenosis (90%), presenting with worsening chest tightness and elevated troponin. 1

Clinical Presentation Assessment

This patient presents with:

• Worsening chest tightness for 3 days that resolves with rest
• Elevated serum troponin (5), indicating myocardial injury
• Normal sinus rhythm on ECG
• Preserved left ventricular function (EF 65%)
• Significant coronary stenosis:
  • Left main coronary artery: 70% stenosis
  • Left anterior descending artery: 80% stenosis
  • Right coronary artery: 90% stenosis

Rationale for CABG Recommendation

The guidelines provide clear direction for this patient:

1. Left Main Disease: CABG is a Class I recommendation for patients with significant (>50% diameter) left main coronary artery stenosis 1

2. Triple-Vessel Disease: CABG is beneficial in patients with significant stenoses in 3 major coronary arteries (>70% diameter) 1

3. Elevated Troponin: The elevated troponin indicates myocardial injury, suggesting unstable angina/NSTEMI, which further supports urgent revascularization

PCI vs. CABG Considerations

While PCI could be considered in some left main disease cases, this patient has multiple high-risk features that favor CABG:

• Complex 3-vessel CAD with left main involvement (likely high SYNTAX score >22)
• Multiple high-grade stenoses (70-90%)
• Clinical presentation with unstable symptoms and positive troponin

The guidelines specifically state that PCI should not be performed in patients with significant unprotected left main CAD who have unfavorable anatomy for PCI and who are good candidates for CABG (Class III: Harm) 1

Management Algorithm

1. Immediate Management:

   • Initiate guideline-directed medical therapy including:
     • Dual antiplatelet therapy (aspirin + P2Y12 inhibitor)
     • High-intensity statin
     • Beta-blocker
     • Anticoagulation (if not contraindicated)

2. Cardiac Surgery Consultation:

   • Urgent referral for CABG evaluation
   • Heart Team discussion if any uncertainty exists

3. Pre-operative Assessment:

   • Evaluate surgical risk
   • Assess comorbidities that might impact surgical outcomes

4. Timing of Surgery:

   • Given the elevated troponin and unstable symptoms, early CABG (within 24-72 hours) should be considered after stabilization on medical therapy

Potential Pitfalls and Caveats

1. Delay in Revascularization: Delaying CABG in a patient with left main disease and elevated troponin increases mortality risk

2. Inappropriate PCI Selection: While PCI might be technically feasible, the evidence strongly favors CABG for this anatomic pattern, especially with triple-vessel disease involving the left main 2

3. Incomplete Revascularization: CABG offers better complete revascularization compared to PCI in complex multi-vessel disease 3

4. Post-CABG Management: Following CABG, comprehensive secondary prevention is essential, including:

   • Long-term antiplatelet therapy
   • High-intensity statin therapy
   • Blood pressure control
   • Lifestyle modifications 4

Conclusion

Based on the most recent and highest quality evidence, CABG is clearly the preferred revascularization strategy for this patient with significant left main disease and triple-vessel involvement. The patient's clinical presentation with chest pain and elevated troponin indicates an unstable condition requiring prompt intervention. While PCI might be considered in some left main cases, the complex coronary anatomy in this case makes CABG the optimal choice for improving survival and reducing future cardiac events.