What cardiac revascularization strategies have a mortality benefit?

Cardiac Revascularization Strategies with Mortality Benefit

CABG provides a definitive mortality benefit over medical therapy alone in patients with left main disease, and over PCI in patients with diabetes and multivessel disease, complex three-vessel disease (SYNTAX score >22), and left ventricular dysfunction (LVEF ≤35%). 1

Left Main Coronary Artery Disease

CABG is the gold standard for left main disease and demonstrates clear survival benefit over medical therapy. 1

• CABG reduces 5-year mortality by 70% compared to medical therapy in patients with significant left main stenosis (>50% diameter stenosis) 1
• PCI is a reasonable alternative to CABG for improving survival only in selected patients with left main disease AND low-to-medium anatomic complexity (SYNTAX score ≤22) where equivalent revascularization can be achieved 1
• In left main disease with high anatomic complexity (SYNTAX score >33), CABG demonstrates superior mortality outcomes compared to PCI 1, 2

Multivessel Disease with Diabetes Mellitus

CABG with LIMA to LAD is mandatory for diabetic patients with multivessel disease involving the LAD—this is the single strongest mortality benefit in coronary revascularization. 1

• Meta-analysis of 14 trials showed CABG reduced mortality by 35% compared to drug-eluting stents in diabetic patients with multivessel disease (7.3% vs 10.4%, OR 0.65, p<0.0001) 3
• The FREEDOM trial demonstrated significantly higher all-cause mortality with PCI versus CABG in diabetic patients at 5 years, with benefits extending to 8 years 1
• One-year mortality in diabetic patients with multivessel disease: CABG 4.4% vs PCI 6.6% (OR 1.5) 1
• This mortality benefit exists regardless of disease complexity—even diabetic patients with low SYNTAX scores benefit from CABG over PCI 1

Complex Three-Vessel Disease

CABG provides mortality benefit in three-vessel disease, with strength of recommendation dependent on LVEF and anatomic complexity. 1, 4

• For patients with three-vessel disease and LVEF >50%, CABG may be reasonable to improve survival (Class 2b recommendation, downgraded from Class 1 based on ISCHEMIA trial results) 1
• Five-year results from SYNTAX trial in three-vessel disease: CABG mortality 9.2% vs PCI 14.6% (p=0.006) 5
• Meta-analysis of 6 trials with 6055 patients showed CABG reduced total mortality by 27% compared to PCI (RR 0.73, p<0.001) at 4.1 years weighted average follow-up 6
• For three-vessel disease with low SYNTAX scores (0-22), PCI is acceptable but still results in significantly higher repeat revascularization (25.4% vs 12.6%, p=0.038) 5
• For intermediate (23-32) or high (≥33) SYNTAX scores, CABG demonstrates clear superiority in mortality, MI, and repeat revascularization 5

Left Ventricular Systolic Dysfunction

CABG improves long-term survival in patients with LVEF ≤35% and multivessel disease. 1, 2

• The STICH trial demonstrated survival benefit of CABG over medical therapy at 10-year follow-up in patients with LVEF ≤35%, though initial 5-year results were neutral 1
• Ten-year survival after CABG in patients with LVEF ≤0.35 was 63%, with significant LVEF improvement from 0.28 to 0.43 at follow-up 7
• Subgroup analyses from Veterans Administration and Coronary Artery Surgery Study showed significant survival benefit with CABG in patients with LV dysfunction, particularly with triple-vessel disease 1

STEMI with Multivessel Disease

Staged PCI of non-infarct arteries after successful primary PCI reduces mortality and MI in hemodynamically stable STEMI patients with multivessel disease. 1

• Complete revascularization via staged PCI (not at time of primary PCI) is Class 1, Level A recommendation to reduce risk of death or MI 1
• In selected patients with complex multivessel disease after successful primary PCI, elective CABG is reasonable to reduce cardiac events 1
• Critical pitfall: Routine PCI of non-infarct artery at time of primary PCI in cardiogenic shock should NOT be performed due to higher risk of death or renal failure (Class 3: Harm) 1

Surgical Technique Factors That Influence Mortality

• LIMA to LAD must be used in every CABG procedure—10-year patency rates exceed 90% 1
• Radial artery conduit is preferred over saphenous vein for the second most important target vessel, providing superior patency, reduced adverse cardiac events, and improved survival 1
• Complete revascularization is independently associated with significant reduction in MACE (72.5% vs 66.7% 5-year freedom from MACE) 4

Decision Algorithm

1. Calculate SYNTAX score for all multivessel disease to assess anatomic complexity 1, 4
2. Assess for diabetes mellitus—if present with multivessel disease including LAD, CABG is mandatory 1
3. Assess LVEF—if ≤35% with multivessel disease, CABG improves survival 1
4. For left main disease: CABG is standard; PCI acceptable only if low-medium complexity and equivalent revascularization achievable 1
5. For three-vessel disease without diabetes and normal LVEF: CABG may be reasonable if SYNTAX score >22; PCI acceptable if SYNTAX score ≤22 but expect higher repeat revascularization 1, 5
6. Mandatory Heart Team discussion for all left main or complex multivessel disease 1, 4

Common Pitfalls to Avoid

• Do not perform PCI in diabetic patients with multivessel disease including LAD when they are acceptable surgical candidates—this is associated with 50% higher 5-year mortality 1
• Do not extrapolate benefits of multivessel PCI in STEMI trials to patients with complex disease—these patients were excluded from those trials 8
• Do not use controlled hypothyroidism or age alone as contraindications to CABG when surgical risk is otherwise acceptable 4, 8
• Do not perform routine PCI of non-infarct arteries during primary PCI in cardiogenic shock 1