Imaging Microvascular Dysfunction and Mechanisms for Female-Male Differences in CAD

Area of Science:

• Cardiology
• Vascular Biology
• Medical Imaging

Background:

• Microvascular dysfunction is typically associated with diffuse epicardial coronary atherosclerosis and endothelial dysfunction, rarely presenting as an isolated condition.
• Coronary artery disease (CAD) manifests differently in women due to smaller coronary arteries, higher blood flow, and increased endothelial shear stress, impacting atherosclerosis development and presentation.

Purpose of the Study:

• To clarify the role of microvascular dysfunction in coronary artery disease.
• To highlight the diagnostic challenges posed by the complex interplay of focal stenosis, diffuse epicardial narrowing, and microvascular dysfunction.
• To emphasize the utility of advanced imaging in guiding management strategies for CAD.

Main Methods:

• Review of current understanding of microvascular dysfunction in CAD.
• Analysis of factors influencing CAD presentation in women.
• Evaluation of diagnostic limitations of standard noninvasive and invasive technologies.
• Focus on quantitative rest-stress myocardial perfusion imaging, particularly positron emission tomography (PET).

Main Results:

• Microvascular dysfunction is often secondary to epicardial atherosclerosis and endothelial dysfunction.
• Women exhibit unique CAD pathophysiology affecting endothelial function and disease progression.
• Standard diagnostic tools struggle with complex CAD involving microvascular and epicardial components.
• Quantitative PET myocardial perfusion imaging, alongside clinical context, offers definitive diagnosis.

Conclusions:

• Quantitative rest-stress myocardial perfusion imaging via PET is crucial for diagnosing complex CAD.
• Definitive diagnosis guides management, including risk factor modification and revascularization for severe epicardial stenosis.
• Understanding sex-specific differences in CAD is vital for effective treatment.