Coronary CT angiography (CCTA) is an evolving noninvasive modality in diagnosis of coronary artery disease (CAD). Its incremental prognostic value over traditional scheme of risk prediction has repeatedly been demonstrated. Beyond the assessment of CAD severity, the prognostic value of CCTA has increased with comprehensive plaque analysis. Certain plaque features on CCTA have a prognostic value in the prediction of future coronary events. The concept of fractional flow reserve (FFR) has been developed as an invasive index of the functional severity of stenosis. FFR represents maximal blood flow to the myocardium supplied by an artery with stenosis as a fraction of normal maximum flow. In moderate stenotic lesion, determining whether to perform PCI based on FFR is a current guideline, and has been proven to reduce unnecessary revascularization procedure and improve clinical prognosis. However, clinical events still occur in patients with FFR >0.80. In a recent study, the prognosis in the vessel with FFR > 0.8 was investigated. However, a comprehensive risk model according to FFR has never been investigated. Therefore, the investigators sought to investigate the prognostic implication of qualitative and quantitative plaque analysis on CCTA according to FFR. The main objective was to develop a comprehensive risk model by using clinical risk factors, FFR, and CCTA parameters.~Patients who underwent CCTA within 90 days before FFR measurement will be included. The study population will be from 2 different registries. The 3V-FFR-FRIENDS registry (NCT0620122050) enrolled a total of 1,136 patients (3,298 vessels). Among them, 299 patients who underwent CCTA within 90 days before FFR measurement will be included. The institutional registry of Tsuchiura Kyodo General Hospital included 448 patients who underwent FFR measurement and CCTA within 90 days. By retrospectively collecting clinical outcome data, coronary angiographic data, physiologic indices, and CCTA data from two registries, the CCTA-FFR Registry for Development of Comprehensive Risk Prediction Model will be created. For 3V FFR-FRIENDS registry (NCT0620122050), the collected clinical data for the previous study will be used, and 5-year outcome data will be collected from Seoul National University Hospital, Keimyung University Dongsan Medical Center, and Inje University Ilsan Paik Hospital. For the Institutional registry of Tsuchiura Kyodo General Hospital registry, the investigators will collect the baseline characteristics of participants, CCTA data, and clinical outcome data followed until Mar 2019.
The investigators sought to investigate the prognostic implication of qualitative and quantitative plaque analysis on coronary CT angiography (CCTA) according to fractional flow reserve (FFR). The main objective was to develop a comprehensive risk model by using clinical risk factors, FFR and CCTA parameters.