What are the pros and cons of Coronary Artery Bypass Grafting (CABG) versus Percutaneous Coronary Intervention (PCI) in patients with 3-vessel disease?

CABG vs PCI in 3-Vessel Disease: Pros and Cons

CABG is the superior revascularization strategy for most patients with 3-vessel disease, providing significantly lower rates of death, myocardial infarction, and repeat revascularization compared to PCI, with the only trade-off being a more invasive procedure and similar stroke rates. 1

CABG Advantages

Survival Benefit:

• CABG reduces all-cause mortality compared to PCI (9.2% vs 14.6% at 5 years), with the survival advantage being even greater when left ventricular ejection fraction is less than 50% 2, 3
• CABG provides mandatory superiority over both PCI and medical therapy alone in improving survival for patients with 3-vessel disease and preserved LVEF 1

Reduced Cardiovascular Events:

• CABG results in significantly lower rates of myocardial infarction (4.0% vs 9.2% at 5 years) 3
• CABG reduces the composite endpoint of death/stroke/MI (14.0% vs 22.0%) and major adverse cardiac and cerebrovascular events (24.2% vs 37.5% at 5 years) 3
• CABG dramatically reduces repeat revascularization procedures (12.6% vs 25.4% at 5 years) 3

Superior Symptom Relief:

• CABG provides greater angina relief and improved physical function at 5 years, particularly in patients with high anatomic complexity 4
• CABG results in better quality of life outcomes on multiple health status domains including angina frequency, physical function, and role emotional scales 4

Specific Patient Populations with Enhanced CABG Benefit:

• Diabetes mellitus: CABG is mandatory over PCI in diabetic patients with 3-vessel disease, with substantially amplified mortality benefit (hazard ratio 2.30 for PCI vs CABG in diabetics compared to 1.51 in non-diabetics) 1, 2, 3
• Left ventricular dysfunction: CABG provides greater benefit when LVEF is ≤35-50%, reducing cardiac death and MACCE compared to PCI 2, 5, 6
• Complex anatomy: CABG demonstrates clear superiority in patients with intermediate (SYNTAX 23-32) or high (SYNTAX ≥33) anatomic complexity 1, 3

CABG Disadvantages

Procedural Invasiveness:

• CABG requires full sternotomy, cardiopulmonary bypass, and longer initial recovery compared to PCI 1
• CABG has higher upfront procedural risk, particularly in patients with STS-predicted operative mortality ≥5% 1

Stroke Risk:

• CABG has similar stroke rates to PCI at 5 years (3.5% vs 3.0%), though this represents no disadvantage rather than an advantage 3

Timing Constraints:

• CABG should be avoided within 3-7 days of acute MI unless there is ongoing ischemia with hemodynamic compromise, as surgical mortality is elevated during this window 2

PCI Advantages

Lower Invasiveness:

• PCI is recommended as an alternative to CABG in patients with low anatomic complexity (SYNTAX score ≤22) where complete revascularization can be achieved, given its lower invasiveness and non-inferior survival in this specific subset 1
• PCI results in shorter initial recovery time and hospital stay 1

Acceptable in Low-Complexity Disease:

• In patients with preserved LVEF, no diabetes, and 3-vessel disease of low-to-intermediate anatomic complexity (SYNTAX ≤22), PCI provides similar completeness of revascularization and generally non-inferior survival 1
• For low SYNTAX score patients (0-22), PCI results in similar rates of MACCE compared to CABG (33.3% vs 26.8%, P=0.21) 3

High-Risk Surgical Candidates:

• PCI is reasonable for patients with clinical characteristics predicting significantly increased surgical risk (STS-predicted mortality ≥5%, severe COPD, prior stroke, prior cardiac surgery) and low anatomic complexity 1

PCI Disadvantages

Higher Repeat Revascularization:

• Even in low SYNTAX score patients where PCI is acceptable, repeat revascularization rates remain significantly higher (25.4% vs 12.6%) 3

Worse Outcomes in Complex Disease:

• PCI is contraindicated (Class III: Harm) in patients with unfavorable anatomy (SYNTAX ≥33) who are good candidates for CABG 1
• In intermediate or high SYNTAX score patients, PCI results in significantly higher rates of death, MI, and repeat revascularization 3

Inferior Outcomes in Diabetes:

• PCI should not be performed in diabetic patients with 3-vessel disease, as CABG provides mandatory superiority 1, 2

Less Durable Symptom Relief:

• PCI provides less angina relief at 5 years, with the difference becoming more pronounced in patients with higher anatomic complexity 4

Decision Algorithm

Step 1: Calculate SYNTAX Score 1

• SYNTAX ≥33: CABG mandatory, PCI contraindicated 1
• SYNTAX 23-32: CABG strongly preferred 3
• SYNTAX ≤22: Either strategy acceptable if complete revascularization achievable 1

Step 2: Assess Diabetes Status 1

• Diabetes present: CABG mandatory regardless of SYNTAX score 1, 2
• No diabetes: Proceed to Step 3

Step 3: Assess Left Ventricular Function 2, 5

• LVEF ≤50%: CABG strongly preferred for survival benefit 2
• LVEF >50%: Proceed to Step 4

Step 4: Assess Surgical Risk 1

• STS-predicted mortality <2% and SYNTAX ≤22: PCI acceptable alternative 1
• STS-predicted mortality ≥5% and SYNTAX ≤22: PCI reasonable 1
• Good surgical candidate with SYNTAX >22: CABG mandatory 1

Critical Pitfalls to Avoid

• Do not defer CABG in asymptomatic or mildly symptomatic patients, as the survival benefit exists regardless of symptom severity in 3-vessel disease 2
• Do not withhold CABG in elderly patients based on age alone, as the benefit-to-risk ratio remains favorable when surgical risk is acceptable 2
• Do not perform PCI in diabetic patients with 3-vessel disease expecting equivalent outcomes to CABG 1, 2
• Do not use controlled hypothyroidism or other well-managed comorbidities as justification for choosing PCI over CABG when CABG is indicated 5
• Ensure Heart Team discussion occurs for all patients with 3-vessel disease to select the most appropriate revascularization modality based on patient profile, coronary anatomy, procedural factors, LVEF, and preferences 1, 5