PreDiction and Validation of Clinical CoursE of Coronary Artery DiSease With CT-Derived Non-Invasive HemodYnamic Phenotyping and Plaque Characterization (DESTINY Study)

Overview

Acute coronary syndrome (ACS) and sudden cardiac death can be the first manifestation of coronary artery disease and are the leading cause of death in the majority of the world's population. The main pathophysiology of ACS is well-known and fibrous cap thickness, presence of a lipid core, and the degree of inflammation have been proposed as the key determinants of plaque vulnerability. Previous studies using virtual histology intravascular ultrasound or optical coherence tomography showed that clinical application of this concept improved risk prediction of ACS. However, these approaches have not been widely adopted in daily practice due to relatively low positive predictive values, low prevalence of high-risk plaques and the invasive nature of diagnostic modalities. Non-invasive imaging studies with coronary computed tomography angiography (CCTA) also showed the clinical value of CCTA-derived high risk plaque characteristics (HRPC). In addition, the recent progress in CCTA and computational fluid dynamics (CFD) technologies enables simultaneous assessment of anatomical lesion severity, presence of HRPC and quantification of hemodynamic forces acting on plaques in patient-specific geometric models. As plaque rupture is a complicated biomechanical process influenced by the structure and constituents of the plaque as well as the external mechanical and hemodynamic forces acting on the plaque, a comprehensive evaluation of lesion geometry, plaque characteristics and hemodynamic parameters may enhance the identification of high-risk plaque and the prediction of ACS risk. In this regard, the current study is designed to evaluate prognostic implications of comprehensive non-invasive hemodynamic assessment using CCTA and CFD in the identification of high risk plaques that caused subsequent ACS.

The study population was collected from Samsung Medical Center. Target population is patients who suffered a clearly documented ACS (acute myocardial infarction \[MI\] or unstable angina with objective evidence of plaque rupture) or those who underwent significant lesion progression in angiography and treated by percutaneous coronary intervention (PCI) and had undergone CCTA from 6 months to 3 years prior to the coronary events. CCTA images were screened for plaque characteristics and CFD analysis at core laboratories in Elucid Bioimaging, Inc, MA, USA and Shanghai Institute of Cardiovascular Diseases, Shanghai, China, respectively. Lesions with diameter stenosis (DS) \> 30% based on CCTA evaluation were included analysis. The presence of conventional CCTA-HRPC (minimum lumen area\<\<4 mm2, plaque burden≥70%, low-attenuation plaque, positive remodeling, napkin-ring sign, and spotty calcification) and parameters from tissue characterization using VascuCAP software will be assessed in each lesion by an independent observer blinded to the clinical data and CFD results. The hemodynamic parameters from CFD will include 1) per-vessel FFR derived from CCTA (FFRCT); 2) change in FFRCT across the lesion (△FFRCT); 3) FFRCT pullback pressure gradient (PPG) index (FFRCT-PPG index); 4) Fractional myocardial mass (FMM) of the target stenosis. Using the occurrence of ACS or PCI for the progressed lesion as clinical endpoint, prognostic implications of CCTA-derived HRPC or hemodynamic parameters will be analyzed.