DOES FLOW-MEDIATED DILATION NORMALIZATION FOR BASE-SCALED SHEAR RATE IMPROVE ITS VALUE IN CORONARY ARTERY DISEASE...

Area of Science:

• Vascular biology
• Cardiovascular diagnostics
• Biomedical engineering

Background:

• Flow-mediated dilation (FMD) is a key indicator of endothelial function.
• Current FMD normalization methods may limit diagnostic accuracy for coronary artery disease (CAD).
• A novel normalization parameter, basal shear rate (BSSR), is proposed.

Purpose of the Study:

• To introduce and validate a new normalization method for FMD in the radial artery using BSSR.
• To assess the efficacy of the FMD/BSSR normalization in differentiating healthy subjects from patients with stable CAD.

Main Methods:

• A new FMD normalization algorithm incorporating BSSR (ratio of basal shear rate to post-occlusive shear rate) was developed.
• The algorithm's in vivo performance was evaluated in healthy volunteers (Group I) and patients with stable CAD (Group II).
• Normalized FMD values (FMD/SR and FMD/BSSR) were compared between groups, and diagnostic performance metrics were calculated.

Main Results:

• The FMD/BSSR normalization revealed a ~50% greater difference between healthy subjects and CAD patients compared to FMD/SR.
• FMD/SR values were (3.19 ± 1.4)•10^-4 in healthy subjects and (1.02 ± 0.76)•10^-4 in CAD patients.
• FMD/BSSR values were 28 ± 9.40 in healthy subjects and 6.01 ± 3.74 in CAD patients.
• Prediction of CAD using FMD/SR had 83.3% sensitivity and 84.6% specificity.
• Prediction of CAD using FMD/BSSR achieved 100% sensitivity and 100% specificity.

Conclusions:

• The novel FMD/BSSR normalization algorithm significantly enhances the differentiation between healthy individuals and patients with stable CAD.
• This improved diagnostic accuracy suggests the FMD/BSSR method is a valuable tool for cardiovascular risk assessment.