What does quantitative coronary angiography (QCA) measure?

What does quantitative coronary angiography (QCA) measure?

• A. Blood pressure, heart rate, ejection fraction, stroke volume.
• B. Flow velocity, shear stress, plaque composition, lumen diameter.
• C. Degree of stenosis, reference vessel size, lesion length, minimal lumen area.
• D. Oxygen saturation, calcium score, lipid levels, age.

Answer: (C)

Quantitative coronary angiography focuses on the geometry of the coronary lumen seen on angiograms to define how narrowed a lesion is. It provides several key measurements that describe the blockage: how much the lumen is narrowed (degree of stenosis, usually expressed as a percent), the size of the reference vessel around the lesion, the length of the lesion, and the minimal lumen area. These metrics come from analyzing the lumen outline and comparing the narrowed segment to a nearby normal reference segment, giving an objective, anatomic assessment of stenosis. This differs from physiological or biological assessments. Flow velocity and shear stress describe how blood moves and forces on the vessel wall, which QCA does not measure. Plaque composition requires intracoronary imaging modalities like IVUS or OCT. Oxygen saturation, calcium score, lipid levels, and age are patient characteristics or systemic risk factors, not anatomic lumen measurements from angiography.

Quantitative coronary angiography focuses on the geometry of the coronary lumen seen on angiograms to define how narrowed a lesion is. It provides several key measurements that describe the blockage: how much the lumen is narrowed (degree of stenosis, usually expressed as a percent), the size of the reference vessel around the lesion, the length of the lesion, and the minimal lumen area. These metrics come from analyzing the lumen outline and comparing the narrowed segment to a nearby normal reference segment, giving an objective, anatomic assessment of stenosis.

This differs from physiological or biological assessments. Flow velocity and shear stress describe how blood moves and forces on the vessel wall, which QCA does not measure. Plaque composition requires intracoronary imaging modalities like IVUS or OCT. Oxygen saturation, calcium score, lipid levels, and age are patient characteristics or systemic risk factors, not anatomic lumen measurements from angiography.