What is triple vessel disease?

Triple Vessel Disease: Definition and Implications

Triple vessel disease (TVD) refers to significant stenosis (≥70% narrowing) in all three major coronary arteries: the left anterior descending (LAD), left circumflex, and right coronary artery. This condition represents an advanced form of coronary artery disease with important implications for patient management and prognosis.

Anatomical Definition and Diagnosis

Triple vessel disease is defined based on coronary angiography findings:

• Significant stenosis (≥70% diameter reduction) in all three major coronary arteries 1
• The three major vessels are considered to be:
  • Left anterior descending coronary artery (LAD)
  • Left circumflex coronary artery
  • Right coronary artery 1
• The circulation should be labeled as "right dominant," "left dominant," or "co-dominant," according to the origin of the posterior descending coronary artery 1

Clinical Significance and Prognosis

Triple vessel disease carries significant prognostic implications:

• Long-term survival is significantly reduced compared to single or double vessel disease
• The 12-year survival rate for patients with triple vessel disease treated medically is approximately 50%, compared to 74% for single vessel disease and 59% for double vessel disease 1
• Annual mortality rate for patients with triple vessel disease can be as high as 6%, compared to 1.5% for those with single or double vessel disease 2
• Prognosis is particularly poor when triple vessel disease is accompanied by:
  • Left ventricular dysfunction
  • Proximal LAD involvement (>95% stenosis) 1
  • Poor exercise capacity on stress testing 2

Management Considerations

The management of triple vessel disease typically requires revascularization:

Coronary Artery Bypass Grafting (CABG)

CABG is generally the preferred treatment for triple vessel disease, particularly in:

• Patients with diabetes and intermediate or high SYNTAX score (>22) 1
• Patients with left ventricular dysfunction (ejection fraction <50%) 1
• Those with complex coronary anatomy 1

Complete revascularization (grafts to three or more vessels) in triple vessel disease significantly improves:

• Survival (90% 5-year survival with three-vessel grafting vs. 85% with two-vessel grafting) 3
• Event-free survival 3
• Symptom relief 3

Percutaneous Coronary Intervention (PCI)

PCI may be considered in triple vessel disease in specific scenarios:

• In patients with low SYNTAX score (0-22) 1
• In patients at high surgical risk 1
• When complete revascularization can be achieved 1, 4

However, PCI in triple vessel disease is associated with higher rates of target vessel revascularization compared to CABG (24.5% vs. 7.1%) 4.

Hybrid Coronary Revascularization

Hybrid revascularization (combining LIMA-LAD bypass with PCI for non-LAD lesions) is an emerging option for selected patients with triple vessel disease, showing comparable 8-year mortality to traditional CABG (5.0% vs. 4.0%) 5.

Special Considerations

• Left ventricular function significantly impacts outcomes in triple vessel disease
• Patients with triple vessel disease and ejection fraction <35% have better outcomes with CABG than with PCI 1
• In patients with severe angina (CCS class III or IV) and triple vessel disease, complete revascularization is particularly important for improving survival and symptom relief 3

Common Pitfalls

1. Underestimating disease severity: Triple vessel disease represents advanced coronary atherosclerosis and carries significant mortality risk if undertreated.

2. Incomplete revascularization: Placing grafts to fewer than three vessels in triple vessel disease is associated with higher mortality, particularly in patients with severe angina or left ventricular dysfunction 3.

3. Relying solely on anatomical assessment: Functional significance of lesions should be assessed, as angiography alone may not reliably indicate the physiological significance of a stenosis 1.

4. Overlooking left ventricular function: Ejection fraction is a critical determinant of prognosis and treatment strategy in triple vessel disease 1, 3.