The invasive investigation of INOCA in the coronary catheterization lab

Area of Science:

• Cardiology
• Vascular Medicine
• Diagnostic Imaging

Background:

• Over 50% of angina patients present without obstructive coronary artery disease.
• A significant subset of these patients may have undiagnosed microvascular dysfunction or vasospastic angina.
• Ischemia with non-obstructive coronary artery disease (INOCA) is frequently underdiagnosed and undertreated.

Purpose of the Study:

• To review the invasive diagnostic strategies for INOCA.
• To highlight the role of coronary flow reserve (CFR) and index of microcirculatory resistance (IMR) in assessing microvascular function.
• To provide an overview of optimal management pathways for INOCA patients.

Main Methods:

• Invasive assessment in the coronary catheterization laboratory.
• Measurement of coronary flow reserve (CFR) to evaluate blood flow through the coronary arteries.
• Assessment of the index of microcirculatory resistance (IMR) to quantify microvascular dysfunction.
• Acetylcholine provocation testing to diagnose coronary vasospasm.

Main Results:

• INOCA can be caused by microvascular dysfunction and/or vasospastic angina.
• CFR and IMR are key invasive parameters for evaluating microvascular function in INOCA.
• Acetylcholine testing is crucial for identifying coronary vasospasm as a cause of INOCA.

Conclusions:

• Invasive evaluation in the cardiac catheterization lab is essential for diagnosing the causes of INOCA.
• Understanding and diagnosing microvascular dysfunction and vasospastic angina are critical for effective angina management in INOCA patients.
• Optimal management of INOCA relies on accurate invasive assessment of coronary physiology.