Which parameter is NOT measured by quantitative coronary angiography (QCA)?

Which parameter is NOT measured by quantitative coronary angiography (QCA)?

• A. Ejection fraction
• B. Degree of stenosis
• C. Reference vessel size
• D. Lesion length

Answer: (A)

Quantitative coronary angiography analyzes the anatomy of the coronary lumen on angiographic images. It quantifies how narrowed a lesion is by calculating percent diameter stenosis using the reference vessel size, measures lesion length along the artery, and estimates the reference vessel size to contextualize the stenosis. Ejection fraction, however, reflects LV pumping function and is obtained from imaging of the heart’s chambers (left ventriculography, echocardiography, or MRI), not from the coronary lumen images. Therefore, the parameter not measured by QCA is ejection fraction.

Quantitative coronary angiography analyzes the anatomy of the coronary lumen on angiographic images. It quantifies how narrowed a lesion is by calculating percent diameter stenosis using the reference vessel size, measures lesion length along the artery, and estimates the reference vessel size to contextualize the stenosis. Ejection fraction, however, reflects LV pumping function and is obtained from imaging of the heart’s chambers (left ventriculography, echocardiography, or MRI), not from the coronary lumen images. Therefore, the parameter not measured by QCA is ejection fraction.