Long-term outcome prediction by functional parameters derived from coronary computed tomography angiography

Area of Science:

• Cardiovascular Imaging
• Interventional Cardiology
• Diagnostic Accuracy

Background:

• Coronary computed tomography angiography (CCTA) is used to assess coronary artery disease (CAD).
• Estimating the hemodynamic significance of coronary stenosis is crucial for patient management.
• Corrected coronary opacification (CCO) decrease and transluminal attenuation gradient (TAG) are emerging as faster alternatives to fractional flow reserve derived from CT (FFR_CT).

Purpose of the Study:

• To evaluate the diagnostic accuracy of CCO decrease and TAG.
• To determine if CCO decrease and TAG offer added prognostic value in patients with suspected CAD.

Main Methods:

• Retrospective study of 162 patients undergoing CCTA for CAD evaluation.
• CCO decrease calculated as normalized difference in luminal coronary attenuation (proximal-distal to stenosis).
• TAG calculated by measuring mean attenuation at 5-mm intervals.
• Major adverse cardiac events (MACE) defined as death, myocardial infarction, unstable angina, or revascularization.

Main Results:

• Follow-up in 154 patients (72 with CAD); 55 experienced MACE over 6.1 years.
• Abnormal CCO decrease associated with worse MACE-free survival in CAD patients (p<0.05).
• TAG was not associated with MACE-free survival (p=0.894).
• Multivariate analysis identified CCO decrease as an independent predictor of MACE (HR 2.27; p=0.02), while TAG was not predictive (p=0.895).

Conclusions:

• CCO decrease provides significant long-term prognostic value in CAD patients.
• TAG does not appear to add prognostic value beyond clinical factors and stenosis severity.
• CCO decrease may be a valuable tool for risk stratification in CAD patients evaluated by CCTA.