Diagnostic Performance of CT-Derived Resting Distal to Aortic Pressure Ratio (Resting Pd/Pa) vs. CT-Derived Fractional Flow Reserve (CT-FFR) in Coronary Lesion Severity Assessment

Source address: https://dx.doi.org/10.21037/atm-21-4325

Quan Li1#, Yang Zhang1#, Chunliang Wang2,3, Shiming Dong4 , Yijin Mao3 , Yida Tang5 , Yong Zeng1

Center for Coronary Artery Disease, Division of Cardiology Beijing Anzhen Hospital, Capital Medical University, Beijing, China; 2 Departement  of Biomedical Engineering and Health Systems, KTH - Royal Institute of Technology, Stockholm, Sweden; 3 Shenzhen Escope Tech Inc., China;  4 Department of Cardiology, Changzheng Hospital, Second Military Medical University, Shanghai, China; 5 Department of Cardiovascular Medicine,  Peking University Third Hospital, Beijing, China

Contributions: (I) Conception and design: Q Li, S Dong, Y Mao; (II) Administrative support: Y Tang, Y Zeng; (III) Provision of study materials or  patients: Q Li, Y Zhang; (IV) Collection and assembly of data: All authors; (V) Data analysis and interpretation: All authors; (VI) Manuscript writing:  All authors; (VII) Final approval of manuscript: All authors.

# These authors contributed equally to this work.

Correspondence to: Yong Zeng, MD. Center for Coronary Artery Disease, Division of Cardiology Beijing Anzhen Hospital, Capital Medical University,  Beijing 100029, China. Email: yzeng_anzhen@163.com; Yida Tang, MD. Department of Cardiovascular Medicine, Peking University Third  Hospital, Beijing 100191, China. Email: tang_yida@163.com.

Background: Computed tomography-derived fractional flow reserve (CT-FFR) has emerged as a  promising non-invasive substitute for fractional flow reserve (FFR) measurement. Normally, CT-FFR  providing functional signifificance of coronary artery disease (CAD) by using a simplified total coronary  resistance index (TCRI) model. Yet the error or discrepancy caused by this simplified model remains unclear.

Methods: A total of 20 consecutive patients with suspected CAD who underwent CTA and invasive FFR  measurement were retrospectively analyzed. CT-FFR and CT-(Pd/Pa)rest values derived from the coronary  CTA images. The diagnostic performance of CT-FFR and CT-(Pd/Pa)rest were evaluated on a per-vessel level  using C statistics with invasive FFR<0.80 as the reference standard.

Results: Of the 25 vessels eventually analyzed, the prevalence of functionally signifificant CAD were 64%.  The Youden index of the ROC curve indicated that the best cutoff value of invasive resting Pd/Pa was 0.945  for identifying functionally significant lesions. Sensitivity, specifificity, negative predictive value, positive  predictive value and accuracy were 85%, 91%, 92%, 83% and 88% for CT-(Pd/Pa)rest and 85%, 58%  69%, 78% and 72% for CT-FFR. Area under the receiver-operating characteristic curve (AUC) to detect  functionally signifificant stenoses of CT-(Pd/Pa)rest and CT-FFR were 0.87 and 0.90.

Conclusions: In this study, the results suggest CT-derived resting Pd/Pa has a potential advantage over  CT-FFR in triaging patients for revascularization.

Keywords: Fractional flow reserve (FFR); computational fluid dynamics; coronary CT angiography; pressure ratio Submitted Jul 23, 2021. Accepted for publication Sep 03, 2021.

doi: 10.21037/atm-21-4325

View this article at: https://dx.doi.org/10.21037/atm-21-4325