Multivessel Disease: Definition and Clinical Significance
Multivessel coronary disease is defined as angiographically significant stenosis of ≥50% in two or more epicardial coronary arteries, occurring in 40-70% of patients with acute coronary syndromes. 1
Precise Angiographic Definition
The threshold for "significant stenosis" varies by vessel location:
- ≥50% diameter stenosis for left main coronary artery disease 1
- ≥70% diameter stenosis for non-left main epicardial vessels 1, 2
- Must involve ≥2 separate epicardial coronary territories (left anterior descending, left circumflex, right coronary artery) 1
The FIRE trial operationalized this definition more specifically as nonculprit arteries with minimum vessel diameter >2.5 mm and angiographic stenosis 50-99%. 1
Clinical Prevalence and Context
Multivessel disease represents a substantial proportion of coronary presentations:
- 40-70% of NSTE-ACS patients have multivessel involvement 1
- Approximately 50% of all acute coronary syndrome patients present with multivessel disease 3
- The presence of multivessel disease fundamentally alters treatment strategy and prognosis compared to single-vessel disease 3
Anatomic Complexity Stratification
The SYNTAX score provides critical risk stratification for treatment decisions in multivessel disease 2:
- Low complexity (SYNTAX ≤22): PCI may be equivalent to CABG 2
- Intermediate complexity (SYNTAX 23-32): CABG generally preferred 2
- High complexity (SYNTAX >32): CABG clearly preferred 2
High-Risk Anatomic Patterns
Certain multivessel patterns carry particularly poor prognosis and influence revascularization strategy 1:
- Significant left main stenosis with high-complexity CAD 1
- Complex or diffuse multivessel CAD 1
- Diabetes mellitus with MVD involving the LAD 1, 2
- Multivessel CAD with severe LV dysfunction 1
- Proximal LAD involvement confers worse prognosis than distal disease 2
Critical Diagnostic Pitfall
Visual angiographic assessment alone has only 70% inter-observer concordance for stenosis severity, dropping to 51% when restricted to vessels with some stenosis. 2 This limitation necessitates physiological assessment in many cases.
Physiological Assessment Integration
When multivessel PCI is considered, fractional flow reserve (FFR <0.80) or instantaneous wave-free ratio (iFR) should be used to define true hemodynamic significance of intermediate lesions (50-70% stenosis). 2, 4 The 2025 ACC/AHA guidelines give this a Class 2b recommendation for nonculprit stenosis assessment in NSTE-ACS. 1
Prognostic Implications
Multivessel disease carries significantly higher risk of recurrent ischemic events and mortality compared to single-vessel disease. 3 The presence of preserved versus impaired ventricular function further stratifies risk:
- EF ≥50%: Requires evaluation for revascularization 2
- EF <50%: Greater survival benefit with CABG over PCI 2
- EF <35%: Requires careful myocardial viability assessment before revascularization decisions 2
Special Population: Cardiogenic Shock
In patients with ACS complicated by cardiogenic shock, multivessel disease has a fundamentally different treatment paradigm. The CULPRIT-SHOCK trial definitively showed that routine PCI of noninfarct-related arteries at the time of primary PCI results in higher rates of death or renal replacement therapy at 30 days and 1 year. 1 This represents a Class 3 Harm recommendation. 1
The critical caveat: CULPRIT-SHOCK only enrolled patients with an identifiable culprit lesion. When there is an unstable-appearing nonculprit or uncertain culprit lesion, the decision becomes more nuanced and requires individualized assessment. 1