Increasing Extracellular Volume Fraction on Coronary CTA in Patients With Coronary Microvascular Dysfunction

Area of Science:

• Cardiology
• Radiology
• Medical Imaging

Background:

• Coronary microvascular dysfunction (CMD) is a key factor in chest pain, particularly in angina with nonobstructive coronary artery disease (ANOCA).
• Coronary computed tomography angiography (CCTA) can assess myocardial fibrosis via extracellular volume fraction (ECV), but its association with CMD in ANOCA is unclear.

Purpose of the Study:

• To investigate the relationship between CCTA-derived ECV and CMD in patients diagnosed with ANOCA.

Main Methods:

• A retrospective analysis of 57 ANOCA patients who underwent CCTA with ECV protocol and invasive functional testing.
• Exclusion criteria included significant epicardial stenosis, prior revascularization, myocardial infarction, or heart failure.
• CMD was defined by a coronary flow reserve <2.5; diastolic dysfunction (DD) was assessed via echocardiography.

Main Results:

• Of 57 patients, 26 (45.6%) had CMD. CMD correlated with age, NT-proBNP, calcium score, DD, and higher ECV.
• CCTA-derived ECV >31.9% was independently associated with CMD (OR, 10.50; P=0.002).
• Diastolic dysfunction (DD) was also an independent predictor (OR, 17.90; P=0.004), and adding ECV to a model with DD improved CMD discrimination (AUC, 0.854).

Conclusions:

• Patients with ANOCA and CMD exhibit significantly elevated ECV and a higher prevalence of DD.
• ECV and DD may serve as crucial biomarkers for tailoring management strategies in ANOCA patients with CMD.