CT-FFR vs a model of combined plaque characteristics for identifying ischemia: Results from CT-FFR CHINA trial

Na Zhao1, Yang Gao1, Bo Xu2

  • 1Department of Radiology, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 167 North Lishi Road, Xicheng District, Beijing, China.

Insights

Fractional flow reserve (FFR) derived from coronary computed tomography angiography (CT-FFR) effectively assesses obstructive coronary artery disease. For nonobstructive disease, plaque characteristics offer a viable alternative to CT-FFR.

Area of Science:

  • Cardiovascular Imaging
  • Interventional Cardiology
  • Diagnostic Accuracy

Background:

  • Coronary computed tomography angiography (CCTA) visualizes coronary anatomy but assessing functional significance of stenosis remains challenging.
  • Fractional flow reserve (FFR) is the gold standard for determining ischemia, but invasive FFR is resource-intensive.
  • CT-derived FFR (CT-FFR) offers a non-invasive method to assess lesion-specific ischemia.

Purpose of the Study:

  • To evaluate the diagnostic performance of CT-FFR and plaque characteristics in identifying ischemia across varying CCTA stenosis levels.
  • To compare the accuracy of CT-FFR against invasive FFR in patients with coronary artery disease (CAD).
  • To identify specific plaque features predictive of ischemia in both obstructive and nonobstructive coronary lesions.

Main Methods:

  • A clinical trial involving 317 patients and 366 vessels with 30%-90% coronary stenosis was conducted across 5 centers.
  • Vessels were categorized into nonobstructive (<50% stenosis) and obstructive (≥50% stenosis) groups.
  • Analysis included lesion length, plaque burden, diameter stenosis, volume ratio of plaque subcomponents <30 HU, and high-risk features. Logistic regression and ROC curve analysis were used to assess diagnostic performance.

Main Results:

  • In obstructive lesions (≥50% stenosis), CT-FFR demonstrated high diagnostic accuracy (AUC=0.90) for ischemia, significantly outperforming plaque characteristics (AUC=0.67).
  • In nonobstructive lesions (<50% stenosis), a combination of plaque characteristics (volume ratio <30 HU and diameter stenosis) showed diagnostic performance (AUC=0.88) comparable to CT-FFR (AUC=0.88).
  • Plaque burden, lesion length, and diameter stenosis were independent predictors of ischemia in nonobstructive lesions.

Conclusions:

  • CT-FFR is a powerful non-invasive tool for assessing functional significance in both obstructive and nonobstructive coronary artery disease.
  • For nonobstructive CAD visualized by CCTA, a model combining specific plaque characteristics can serve as a valuable alternative to CT-FFR.
  • This study highlights the complementary roles of anatomical and functional assessments in managing coronary artery disease.
Abstract