Invasive Detection of Coronary Microvascular Dysfunction: How It Began, and Where We Are Now

Area of Science:

• Cardiology
• Vascular Biology
• Diagnostic Methods

Background:

• Contemporary interventional cardiology practice has evolved beyond focusing solely on epicardial stenosis.
• Microcirculatory dysfunction is increasingly recognized as a key contributor to acute and chronic coronary syndromes.
• Accurate characterization of the microcirculation has significant clinical implications for patient management.

Purpose of the Study:

• To review the methodologies for the invasive diagnosis of microvascular dysfunction.
• To highlight the key indices derived from these diagnostic methods.
• To emphasize the growing importance of microcirculatory assessment in interventional cardiology.

Main Methods:

• Review of current literature and established techniques for invasive assessment of coronary microcirculation.
• Discussion of pressure-wire and thermodilution techniques for evaluating microvascular function.
• Explanation of derived indices such as index of microvascular resistance (IMR) and coronary flow reserve (CFR).

Main Results:

• Invasive assessment provides objective data on microcirculatory function, complementing epicardial stenosis evaluation.
• Key indices derived from invasive methods allow for quantitative assessment of microvascular resistance and flow.
• These methodologies are becoming integral to the interventional cardiologist's diagnostic armamentarium.

Conclusions:

• The invasive diagnosis of microvascular dysfunction is a critical advancement in interventional cardiology.
• Understanding and quantifying microcirculatory function is essential for comprehensive coronary artery disease management.
• This review provides a foundation for interpreting invasive microvascular assessment techniques and their clinical relevance.