When is percutaneous coronary intervention (PCI) indicated?

Indications for Percutaneous Coronary Intervention

Percutaneous coronary intervention (PCI) is primarily indicated for patients with acute coronary syndromes and for those with stable coronary artery disease who have significant symptoms despite optimal medical therapy or who have high-risk anatomical or functional findings. 1

Acute Coronary Syndromes

ST-Elevation Myocardial Infarction (STEMI)

• Primary PCI is the preferred reperfusion strategy when:
  • Can be performed within 90 minutes of first medical contact at PCI-capable hospitals 1
  • Can be performed within 120 minutes when patient presents to a non-PCI capable hospital 1
  • For patients in cardiogenic shock who are less than 75 years old and within 36 hours of MI 1
  • Reasonable for selected patients ≥75 years with good functional status who develop shock within 36 hours of MI 1

Non-ST Elevation Acute Coronary Syndrome (NSTE-ACS)

• Early invasive strategy (within 24-48 hours) is indicated for:
  • Refractory angina
  • Hemodynamic or electrical instability
  • Elevated cardiac biomarkers
  • High-risk features on non-invasive testing
  • GRACE risk score >140 1

Stable Coronary Artery Disease

Symptomatic Patients

• PCI is indicated for patients with:
  • Canadian Cardiovascular Society (CCS) class III or IV angina despite optimal medical therapy 1
  • Moderate to severe ischemia on non-invasive testing 1
  • Single or multi-vessel disease with suitable anatomy and high likelihood of procedural success 1

Specific Anatomical Considerations

• PCI is reasonable for:
  • Significant proximal LAD disease (>70% stenosis) with evidence of ischemia 1
  • Multi-vessel disease not suitable for CABG with evidence of ischemia 1
  • Significant left main disease (>50% stenosis) in patients not eligible for CABG 1

Special Situations

Post-CABG Patients

• PCI is indicated for:
  • Early ischemia (usually within 30 days) after CABG 1
  • Ischemia occurring 1-3 years after CABG with preserved LV function and discrete lesions in graft conduits 1
  • Disabling angina due to new disease in native coronary circulation 1
  • Diseased vein grafts more than 3 years after CABG 1
  • When technically feasible in patients with patent left internal mammary artery graft who have significant obstructions in other vessels 1

Technical Considerations

• Use of distal embolic protection devices is recommended when performing PCI to saphenous vein grafts 1

Contraindications to PCI

Class III (Not Recommended)

• Insignificant disease (<50% coronary stenosis) 1
• Only a small area of myocardium at risk 1
• Lesions with low likelihood of successful dilatation 1
• High risk of procedure-related morbidity or mortality 1
• Significant left main CAD in patients who are candidates for CABG 1
• Chronic total vein graft occlusions 1
• Totally occluded infarct artery >24 hours after STEMI in hemodynamically stable, asymptomatic patients without evidence of severe ischemia 1
• PCI in non-infarct arteries during primary PCI for STEMI without hemodynamic compromise 1

Important Clinical Considerations

Symptom Relief vs. Mortality Benefit

• The primary benefit of PCI in stable coronary artery disease is symptom relief rather than reduction in mortality or MI 1, 2, 3
• In patients with stable CAD, multiple randomized trials have shown no difference between PCI and optimal medical therapy in terms of mortality or MI risk 2, 3
• Approximately 13% of patients may have persistent angina after PCI, with residual chronic total occlusions being a significant predictor 4

Timing Considerations

• In stable patients, a trial of optimal medical therapy is recommended before proceeding to PCI 1
• For patients requiring non-cardiac surgery, elective PCI should not be performed within 4-6 weeks of planned surgery if antiplatelet therapy will need to be discontinued 1

Decision-Making Pitfalls

• Avoid the "oculostenotic reflex" - the tendency to intervene on all visualized stenoses regardless of functional significance 5
• Non-clinical factors that may inappropriately influence PCI decisions include:
  • Patient anxiety
  • Physician concern about missing future events
  • Medicolegal considerations 5
• Always assess functional significance of stenoses rather than relying solely on angiographic appearance 3, 5

PCI offers significant symptomatic improvement for appropriately selected patients, but patient selection should be guided by evidence-based indications focusing on symptom severity, ischemic burden, and coronary anatomy rather than non-clinical factors.