Does coronary flow trump coronary anatomy?

Area of Science:

• Cardiology
• Interventional Cardiology
• Medical Imaging

Background:

• Coronary artery disease (CAD) management traditionally relies on anatomical stenosis severity.
• Revascularization in CAD has not consistently improved mortality compared to medical treatment in randomized trials.
• Coronary flow is often poorly correlated with the degree of stenosis in patients.

Purpose of the Study:

• To investigate whether coronary function (flow) or anatomy (stenosis) better optimizes CAD management.
• To explain the paradoxes observed between stenosis severity, coronary flow, and revascularization outcomes.
• To propose a shift in CAD management strategy from anatomical stenosis to functional flow assessment.

Main Methods:

• Comparison of percutaneous intervention (PCI) guided by fractional flow reserve (FFR) versus arteriographic stenosis.
• Analysis of the relationship between coronary flow reserve (CFR) and stenosis severity.
• Review of randomized trial data on revascularization outcomes versus medical treatment.

Main Results:

• PCI guided by FFR demonstrated superior reduction in coronary events compared to PCI guided by arteriographic stenosis.
• A poor relationship exists between coronary flow reserve and stenosis severity, particularly in diffuse CAD.
• Revascularization strategies based solely on anatomical stenosis have not improved mortality over medical therapy.

Conclusions:

• The concept of "critical" coronary stenosis may be less relevant than "critical" coronary flow reserve reduction for CAD management.
• Functional assessment using FFR offers a more effective approach for guiding PCI in CAD.
• Clinical practice for CAD should consider prioritizing functional flow assessment over anatomical stenosis severity.