Are coronary interventions necessary in patients with Chronic Coronary Syndrome (CCS)?

Are Coronary Interventions Necessary in Chronic Coronary Syndrome?

Yes, coronary interventions are necessary in CCS, but only for specific anatomical patterns and clinical scenarios—not for all patients with stable coronary disease. The decision depends critically on coronary anatomy, left ventricular function, symptom burden despite medical therapy, and the extent of functionally significant disease.

When Revascularization Improves Survival (Not Just Symptoms)

Coronary intervention is mandatory for survival benefit in these anatomical patterns:

High-Risk Anatomy (LVEF >35%)

• Left main stenosis: Revascularization is recommended over medical therapy alone to improve survival 1
• Three-vessel disease: Revascularization is recommended to improve long-term survival, reduce cardiovascular mortality, and decrease spontaneous MI risk 1
• Single- or two-vessel disease involving proximal LAD: Revascularization is recommended to reduce long-term cardiovascular mortality and spontaneous MI 1

Reduced LVEF (≤35%)

• Multivessel disease with LVEF ≤35%: CABG is recommended over medical therapy alone to improve long-term survival 1, 2
• For high surgical risk patients with LVEF ≤35%, PCI may be considered as an alternative, though evidence is weaker 1

When Revascularization Is For Symptom Relief Only

For persistent angina despite guideline-directed medical therapy, revascularization of functionally significant obstructive CAD is recommended to improve symptoms 1. This is the primary indication for:

• Single- or two-vessel disease NOT involving proximal LAD: PCI is recommended for symptom improvement when medical therapy fails 1
• These patients do NOT get a survival benefit—only quality of life improvement through angina reduction

Critical Prerequisite: Functional Significance Must Be Demonstrated

A key pitfall is assuming anatomical stenosis equals clinical relevance. Intracoronary pressure measurement (FFR or iFR) or computation (QFR) is recommended to guide lesion selection for intervention in multivessel disease 1. This prevents unnecessary procedures on non-flow-limiting lesions.

The Medical Therapy Threshold

Revascularization should only be considered after insufficient response to guideline-directed medical therapy 1. This means optimized:

• Antiplatelet therapy
• Beta-blockers
• Statins
• ACE inhibitors/ARBs
• Anti-anginal medications

The exception is high-risk anatomy (left main, three-vessel disease, proximal LAD involvement), where revascularization provides survival benefit regardless of symptom control on medications.

Choosing Between PCI and CABG

The choice of revascularization modality depends on anatomical complexity:

CABG Preferred

• Multivessel disease with diabetes: CABG is recommended over PCI and medical therapy alone to improve symptoms and outcomes 1
• Left main with high SYNTAX score (≥33): PCI is not recommended 1
• Complex proximal LAD disease less amenable to PCI: CABG is recommended to improve symptoms and reduce revascularization rates 1

PCI Acceptable Alternative

• Left main with low SYNTAX score (≤22): PCI is recommended as alternative to CABG, given lower invasiveness and non-inferior survival 1
• Left main with intermediate SYNTAX score (23-32): PCI should be considered as alternative 1
• Three-vessel disease without diabetes, low-to-intermediate complexity: PCI is recommended when complete revascularization achievable, given lower invasiveness and generally non-inferior survival 1

Common Pitfalls to Avoid

Do not perform PCI solely based on anatomical stenosis without functional assessment. The ORBITA trial demonstrated surprisingly small effect sizes for PCI in stable CAD, suggesting that not all anatomical stenoses cause clinical symptoms 3. Always confirm functional significance with FFR/iFR in multivessel disease 1.

Do not assume all angina is ischemic. Up to 75% of HFpEF patients may have coronary microvascular dysfunction rather than epicardial stenosis 1. Functional imaging should be considered to detect both CMD and epicardial CAD in these patients 1.

Heart Team discussion is recommended for complex cases, particularly when CABG and PCI hold the same level of recommendation, to select the most appropriate treatment for patient outcomes and quality of life 1.

Bottom Line Algorithm

1. Identify anatomy: Left main, three-vessel, proximal LAD involvement, or lesser disease?
2. Assess LVEF: >35% or ≤35%?
3. Confirm functional significance: Use FFR/iFR for multivessel disease
4. Optimize medical therapy first (unless high-risk anatomy present)
5. If persistent symptoms or high-risk anatomy: Proceed to revascularization
6. Choose modality: CABG for diabetes + multivessel, high SYNTAX scores, or complex anatomy; PCI for lower complexity when complete revascularization achievable

The evidence clearly shows that not all CCS patients need intervention—only those with high-risk anatomy for survival benefit, or those with functionally significant disease and refractory symptoms for quality of life improvement 1.