Clinical Quick Reference — AUC Rating System for PCI vs CABG
This guideline provides Appropriate Use Criteria (AUC) for coronary revascularization in patients with stable ischemic heart disease (SIHD). The AUC rating system helps clinicians systematically assess whether PCI (percutaneous coronary intervention) or CABG (coronary artery bypass grafting) is appropriate for each patient based on anatomy, risk stratification, symptom status, and antianginal therapy.
Certain anatomic patterns—particularly left main disease, 3-vessel disease, and proximal LAD involvement—are associated with improved survival when revascularized versus managed medically. These are highlighted throughout the tables.
| Anatomic Setting | CABG vs PCI | Typical Approach |
|---|---|---|
| Left main or 3-vessel CAD | CABG preferred for survival benefit | Strongly consider CABG (especially complex anatomy or high surgical risk) |
| 2-vessel CAD with proximal LAD | CABG may offer survival benefit | Shared decision-making; PCI reasonable if low complexity |
| 1-vessel or 2-vessel without prox LAD | Survival benefit unclear | Symptom relief and ischemia reduction primary goals |
1-Vessel Disease: Significant stenosis (≥50% luminal narrowing) in 1 major epicardial artery.
2-Vessel Disease: Significant stenosis in 2 major epicardial arteries. Special distinction: Presence or absence of proximal LAD involvement changes management significantly.
3-Vessel Disease: Significant stenosis in all 3 major epicardial arteries (LAD, LCx, RCA). Complexity increases with SYNTAX score ≥23 (intermediate/high complexity).
Left Main CAD: Significant stenosis in left main coronary artery. Generally associated with high-risk anatomy. May involve ostial, mid-shaft, or bifurcation disease. Often evaluated by angiography, FFR, and intravascular ultrasound (IVUS).
Risk is stratified by noninvasive testing findings (stress test, imaging) and clinical features:
| Risk Category | Annual Mortality/MI Risk | Example Findings |
|---|---|---|
| High Risk | ≥3% annual death or MI | Severe resting LV dysfunction (LVEF <35%), multiple abnormal segments on stress, inducible wall motion abnormality with >10% myocardial involvement, stress-induced ischemia with ≥10% CAC |
| Intermediate Risk | 1–3% annual death or MI | Mild/moderate resting LV dysfunction (LVEF 35–49%), 1 mm ST-segment depression on resting ECG, stress ischemia in 1–9% of myocardium |
| Low Risk | <1% annual death or MI | Normal stress test, no resting wall motion abnormality, CAC score <100 Agatston units |
FFR ≤0.80 is abnormal and consistent with hemodynamically significant (ischemia-causing) stenosis. FFR is increasingly used in the cath lab to guide PCI decisions, especially in intermediate stenosis or when anatomy is ambiguous.
FFR >0.80 suggests the stenosis is not causing significant ischemia and revascularization may not improve symptoms or survival.
For complex 3-vessel and left main disease, the SYNTAX score quantifies angiographic complexity:
| SYNTAX Score | Complexity | Clinical Implication |
|---|---|---|
| <23 | Low Complexity | PCI and CABG outcomes similar; both acceptable |
| 23–32 | Intermediate Complexity | Consider both approaches; shared decision-making |
| >32 | High Complexity | CABG generally preferred; PCI has worse outcomes |
Angina symptoms determine which columns apply in the AUC tables below:
Asymptomatic: Patient has no anginal symptoms or equivalent.
Ischemic Symptoms: Patient reports angina, dyspnea, or equivalent ischemic symptoms. These may be described as typical (substernal chest discomfort with exertion) or atypical (jaw pain, arm pain, dyspnea, fatigue).
Tables distinguish patients by current antianginal regimen:
| Therapy Status | Description |
|---|---|
| Not on AA Therapy or with AA Therapy | Patient not taking antianginal drugs (beta-blockers, CCBs, nitrates, etc.) or already on AA therapy |
| On 1 AA Drug (BB Preferred) | Patient on a single antianginal agent; beta-blockers are preferred as first-line |
| On ≥2 AA Drugs | Patient on 2 or more antianginal agents and still symptomatic (refractory angina) |
Each indication also specifies whether stress test/imaging findings are:
One-vessel disease (single epicardial artery with ≥50% stenosis) generally does not confer a survival benefit from revascularization compared to medical therapy. Management focuses on symptom relief and ischemia reduction.
| Clinical Scenario | PCI | CABG | Notes |
|---|---|---|---|
| Asymptomatic, Low-Risk Findings | 3 | 3 | Revascularization not indicated; medical therapy alone |
| Asymptomatic, Intermediate/High-Risk Findings | 2a | 3 | PCI may be reasonable; CABG not indicated for single-vessel disease |
| Symptomatic (1 AA Drug), Low-Risk Findings | 2b | 3 | Consider PCI if refractory to medical optimization |
| Symptomatic (1 AA Drug), Intermediate/High-Risk Findings | 2a | 3 | PCI appropriate for symptom relief and ischemia reduction |
| Symptomatic (≥2 AA Drugs), Any Risk | 2a | 3 | Refractory angina; PCI may provide symptom relief |
Two-vessel disease is stratified by proximal LAD involvement and diabetes status. Proximal LAD stenosis is considered higher-risk anatomy and may be associated with larger ischemic burden.
| Clinical Scenario | PCI | CABG | Notes |
|---|---|---|---|
| Asymptomatic, Low-Risk Findings | 3 | 3 | Revascularization not indicated; medical therapy |
| Asymptomatic, Intermediate/High-Risk Findings | 2b | 3 | PCI may be considered; CABG not indicated |
| Symptomatic (1 AA Drug), Low-Risk Findings | 2a | 3 | PCI appropriate for symptom relief |
| Symptomatic (1 AA Drug), Intermediate/High-Risk Findings | 2a | 2a | Both PCI and CABG reasonable; shared decision-making |
| Symptomatic (≥2 AA Drugs), Any Risk | 2a | 2a | Refractory angina; both approaches reasonable |
Proximal LAD involvement increases mortality risk and shifts recommendations toward more aggressive revascularization, particularly with ischemic symptoms or high-risk findings.
| Clinical Scenario | PCI | CABG | Notes |
|---|---|---|---|
| Asymptomatic, Low-Risk Findings | 3 | 3 | Revascularization not indicated; medical therapy |
| Asymptomatic, Intermediate/High-Risk Findings | 2a | 2b | PCI or CABG may be considered; PCI slightly favored |
| Symptomatic (1 AA Drug), Low-Risk Findings | 2a | 2a | Both approaches reasonable; PCI or CABG by local expertise |
| Symptomatic (1 AA Drug), Intermediate/High-Risk Findings | 2a | 2a | Both approaches reasonable; consider CABG if complex anatomy |
| Symptomatic (≥2 AA Drugs), Any Risk | 2a | 2a | Both approaches appropriate; CABG may be preferred if complex |
Three-vessel disease is the highest-risk subset and is associated with improved survival when revascularized (either PCI or CABG) compared to medical therapy alone. Disease complexity (SYNTAX score) and diabetes status are key decision points. Use the SYNTAX Score calculator to quantify complexity.
| Clinical Scenario | PCI | CABG | Notes |
|---|---|---|---|
| Asymptomatic, Low-Risk Findings, No Diabetes | 2b | 2b | Either approach reasonable; medical therapy also acceptable |
| Asymptomatic, Intermediate/High-Risk Findings, No Diabetes | 2a | 2a | Revascularization appropriate; PCI or CABG acceptable |
| Any Symptom Status, Diabetes Present | 2a | 2a | Revascularization appropriate in diabetic patients with 3-vessel disease |
| Symptomatic (≥1 AA Drug), Any Risk, No Diabetes | 2a | 2a | Revascularization appropriate; both approaches reasonable |
Higher SYNTAX scores shift the balance toward CABG, particularly in diabetic patients and those with ischemic symptoms.
| Clinical Scenario | PCI | CABG | Notes |
|---|---|---|---|
| Asymptomatic, Low-Risk Findings, No Diabetes | 2b | 2b | Either approach may be considered; medical therapy also acceptable |
| Asymptomatic, Intermediate/High-Risk Findings, No Diabetes | 2b | 2a | CABG preferred; PCI may be considered in selected patients |
| Asymptomatic, Any Risk, Diabetes | 2b | 2a | CABG favored in diabetic patients with complex 3-vessel disease |
| Symptomatic (1 AA Drug), No Diabetes | 2a | 2a | Both approaches reasonable; shared decision-making |
| Symptomatic (1 AA Drug), Diabetes | 2b | 2a | CABG preferred in diabetic patients; PCI less favorable long-term |
| Symptomatic (≥2 AA Drugs), No Diabetes | 2a | 2a | Revascularization appropriate; both approaches reasonable |
| Symptomatic (≥2 AA Drugs), Diabetes | 2b | 2a | CABG favored for long-term outcomes in complex anatomy + diabetes |
Left main (LM) disease is high-risk anatomy and generally associated with improved survival after revascularization. Both PCI and CABG are options, though CABG has traditionally been favored. SYNTAX score and disease location (ostial, bifurcation, simple stenosis) guide the choice.
| Clinical Scenario | PCI | CABG | Notes |
|---|---|---|---|
| Asymptomatic, Low-Risk Findings | 2a | 2a | Both approaches reasonable; shared decision-making |
| Asymptomatic, Intermediate/High-Risk Findings | 2a | 2a | Revascularization indicated; both approaches acceptable |
| Symptomatic (1 AA Drug) | 2a | 2a | Both approaches appropriate; consider local expertise and anatomy |
| Symptomatic (≥2 AA Drugs) | 2a | 2a | Revascularization indicated; both approaches reasonable |
Complex left main bifurcation or left main with concurrent 3-vessel disease shifts toward CABG, especially with high SYNTAX scores or diabetes.
| Clinical Scenario | PCI | CABG | Notes |
|---|---|---|---|
| LMCA + 3-Vessel, Low SYNTAX, No Diabetes | 2a | 2a | Both approaches reasonable |
| LMCA + 3-Vessel, High SYNTAX or Diabetes | 2b | 2a | CABG preferred; complex anatomy favors surgery |
| LMCA Bifurcation with Diabetes | 2b | 2a | CABG generally preferred; improved long-term outcomes |
Patients with prior CABG may develop stenosis in native coronary arteries or bypass grafts. Management depends on graft patency and the pattern of recurrent disease.
| Clinical Scenario | PCI | CABG | Notes |
|---|---|---|---|
| Stenosis Supplying 1 Territory (Low-Risk) | 2a | 2b | PCI preferred; avoids repeat surgery; IMA usually still patent |
| Stenosis Supplying 1 Territory (Intermediate/High-Risk) | 2a | 2b | PCI reasonable; repeat CABG only if PCI fails or high-risk anatomy |
| Stenosis Supplying 2 Territories | 2a | 2a | Both approaches reasonable; consider PCI vs redo CABG by anatomy |
| Clinical Scenario | PCI | CABG | Notes |
|---|---|---|---|
| Stenosis Supplying 1 Territory (LAD) | 2a | 2b | PCI preferred; LAD now supplied by native vessel or patent SVG |
| Stenosis Supplying 2 Territories (including LAD) | 2a | 2a | Both approaches reasonable; repeat CABG if good conduit options |
| Stenosis Supplying ≥3 Territories or Complex Disease | 2b | 2a | Redo CABG may be preferred if anatomy suitable; higher morbidity |
Patients may undergo coronary revascularization concurrent with other cardiac or non-cardiac procedures (renal transplantation, valve surgery, etc.). Management depends on the urgency of the concurrent procedure and the urgency of revascularization.
Patients undergoing renal transplantation with SIHD have unique considerations: transplant improves long-term survival, but cardiac events remain a major cause of death. Revascularization may be indicated to reduce perioperative and long-term cardiac risk.
| Anatomy & Risk | PCI | CABG | Notes |
|---|---|---|---|
| One-Vessel, Low Ischemia, No Diabetes | 2b | 3 | PCI may reduce perioperative risk; medical therapy also reasonable |
| One- to Two-Vessel, Intermediate Risk, ± Diabetes | 2a | 2a | PCI reasonable as bridge to transplant; CABG for high-risk anatomy |
| Left Main or 3-Vessel, High-Risk | 2a | 2a | Revascularization before transplant; CABG or PCI by anatomy |
Patients undergoing transcatheter valve procedures with concurrent CAD require coordinated revascularization strategy.
| Anatomy & Risk | PCI (Staged or Concurrent) | CABG | Notes |
|---|---|---|---|
| One- to Two-Vessel, Low-Int Complexity | 2a | 2b | PCI before or concurrent with valve procedure |
| Left Main or 3-Vessel, High Complexity | 2b | 2a | Consider CABG + valve surgery vs staged PCI then valve |
Use these calculators to integrate complex data and stratify risk when applying AUC to your patient:
Quantify angiographic complexity in multivessel disease. Essential for PCI vs CABG decisions in 3-vessel and left main disease.
Estimate 10-year atherosclerotic CVD risk. Informs risk stratification and baseline cardiovascular status.
Estimate perioperative mortality risk for CABG surgery. Helps quantify surgical risk and inform CABG vs PCI decisions.
Estimate optimal duration of dual antiplatelet therapy after PCI. Balances thrombotic and bleeding risks.
Classic 10-year coronary heart disease risk model. Useful for baseline risk assessment in stable CAD.
Assess completeness of revascularization after PCI. Higher residual SYNTAX predicts worse long-term outcomes.