What is triple vessel disease?

What is Triple Vessel Disease

Triple vessel disease is defined as significant stenosis (≥70% diameter reduction) affecting all three major coronary artery territories: the left anterior descending artery (LAD), the left circumflex artery, and the right coronary artery. 1, 2

Anatomic Definition

• The diagnosis requires ≥70% luminal diameter reduction in the proximal or mid segments of each of the three major coronary arteries 1, 2
• For the left main coronary artery specifically, a lower threshold of ≥50% stenosis is considered significant 1
• The coronary circulation must be classified as right dominant, left dominant, or co-dominant based on the origin of the posterior descending artery 1
• The three "vessels" refer specifically to: the LAD, the right coronary artery (or posterior descending artery in left-dominant systems), and the left circumflex artery with its major marginal branches 1

Clinical Significance and Prognosis

• Triple vessel disease carries substantial prognostic implications, with medically treated patients experiencing a 5-year survival rate of only 80.7% and 10-year survival of 64.2%, with an annual cardiac event rate of 4.7% 3
• Patients with preserved left ventricular function (ejection fraction ≥50%) and triple vessel disease require evaluation for revascularization to improve survival and outcomes 2, 1
• The presence of left ventricular dysfunction (ejection fraction <50%) confers even greater mortality risk and amplifies the survival benefit from coronary artery bypass grafting (CABG) 1, 2
• Proximal LAD involvement within triple vessel disease carries worse prognosis than distal disease alone 2

Anatomic Complexity Assessment

• The SYNTAX score should be calculated to assess anatomical complexity in all patients with triple vessel disease, as this directly guides revascularization strategy selection 1, 4, 5
• Low complexity disease (SYNTAX score ≤22) may allow consideration of percutaneous coronary intervention (PCI) as an alternative to CABG in select patients 1, 5, 2
• Intermediate complexity (SYNTAX score 23-32) generally favors CABG over PCI 2
• High complexity disease (SYNTAX score >32) mandates CABG as the preferred revascularization strategy 5, 2

Important Clinical Caveats

• Angiographic assessment has limitations, with only 70% concordance between observers for stenosis severity, decreasing to 51% when restricted to vessels with some stenosis 2
• Physiological evaluation with fractional flow reserve (FFR <0.80) may be necessary to define the true hemodynamic significance of intermediate lesions (50-70% stenosis) 2
• The presence of diabetes mellitus in patients with triple vessel disease strongly favors CABG over PCI regardless of anatomic complexity 1, 5, 2
• Extensive ischemia documented by non-invasive stress testing increases the urgency and indication for revascularization 1, 2