The transluminal attenuation gradient does not add diagnostic accuracy to coronary computed tomography

Area of Science:

• Cardiovascular Imaging
• Radiology
• Medical Diagnostics

Background:

• Coronary computed tomography angiography (CCTA) accuracy is crucial to prevent unnecessary invasive procedures.
• Transluminal attenuation gradient (TAG) is a proposed alternative to CT perfusion and CT fractional flow reserve (FFR) for assessing coronary artery stenosis.

Purpose of the Study:

• To assess the incremental diagnostic value of three TAG measurement methods.
• To compare TAG's performance against invasive fractional flow reserve (FFR) as the gold standard.

Main Methods:

• TAG was measured using two semi-automatic and one manual method.
• Receiver operating characteristic (ROC) analysis evaluated TAG alone and combined with CCTA for detecting significant stenosis (FFR ≤0.80).

Main Results:

• The study included 51 coronary vessels from 37 patients; 13 had significant stenoses by FFR.
• TAG alone showed limited diagnostic performance (AUCs 0.520-0.557).
• Combining TAG with CCTA did not significantly improve stenosis detection (AUCs 0.562-0.569).

Conclusions:

• TAG measurement in single-heartbeat CCTA offers no incremental value.
• TAG does not enhance the assessment of coronary artery stenosis severity compared to CCTA alone.