Hyung Yoon Kim1, Hong-Seok Lim2, Joon-Hyung Doh3, Chang-Wook Nam4, Eun-Seok Shin5, Bon-Kwon Koo6, Myeong-Ho Yoon2, Seung-Jea Tahk2, Doo Kyoung Kang7, Young Bin Song1, Joo-Yong Hahn1, Seung Hyuk Choi1, Hyeon-Cheol Gwon1, Sang-Hoon Lee1, Eun-Kyoung Kim1, Sung Mok Kim8, Yeonhyeon Choe8, Jin-Ho Choi9. 1. Department of Medicine, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea. 2. Department of Cardiology, Ajou University School of Medicine, Suwon, Korea. 3. Department of Medicine, Inje University Ilsan-Paik Hospital, Goyang, Korea. 4. Department of Medicine, Keimyung University Dongsan Medical Center, Daegu, Korea. 5. Department of Cardiology, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, South Korea. 6. Department of Medicine, Seoul National University Hospital, Seoul, Korea. 7. Department of Radiology, Ajou University School of Medicine, Suwon, Korea. 8. Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea. 9. Department of Medicine, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea; Department of Emergency Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea. Electronic address: jhchoimd@gmail.com.
Abstract
OBJECTIVES: This study investigated the role of fractional myocardial mass (FMM), a vessel-specific myocardial mass, in the evaluation of physiological severity of stenosis. Using computed tomography angiography, the study investigated fractional myocardial mass, a concept of myocardial mass subtended by specific vessel, which could reduce anatomical-physiological mismatch. BACKGROUND: Discordance between anatomical stenosis and physiological severity is common but remains poorly understood. METHODS: This multicenter study enrolled 463 patients with 724 lesions, who underwent coronary computed tomography angiography (CCTA) and invasive coronary angiography with fractional flow reserve (FFR) measurement. FMM was assessed by allometric scaling analysis of arterial tree length and myocardial mass from CCTA. RESULTS: FFR <0.80, a criteria for vessel-specific physiological stenosis, was found in 281 vessels (39%). FMM decreased consistently according to the vessel downstream (p < 0.001, all). The frequency of FFR <0.80 increased in proportion to FMM and inverse proportion to angiographic minimal luminal diameter (MLD) (p < 0.001). In per-vessel analysis, FMM per MLD (FMM/MLD) showed good correlation with FFR (r = 0.61) and was superior to diameter stenosis (DS) for FFR <0.80 by receiver operating characteristic and reclassification analysis (C-statistics = 0.84 versus 0.74, net reclassification improvement [NRI] = 0.63, integrated discrimination improvement [IDI] = 0.18; p < 0.001, all). The optimal cutoff of FMM/MLD was 29 g/mm, with sensitivity = 75%, specificity = 77%, positive predictive value = 68%, negative predictive value = 83%, and accuracy = 77%. Addition of FMM/MLD to DS could further discriminate vessels with FFR <0.80 (C-statistic = 0.86 vs. 0.84, NRI = 0.34, IDI = 0.03; p < 0.005, all). In per-range classification analysis, agreement between FFR and FMM/MLD maintained >80% when the severity of disease was away from cutoff. CONCLUSIONS: FMM/MLD could find physiological severity of coronary artery with higher accuracy than anatomical stenosis. FMM may explain the anatomical-physiological discordance.
OBJECTIVES: This study investigated the role of fractional myocardial mass (FMM), a vessel-specific myocardial mass, in the evaluation of physiological severity of stenosis. Using computed tomography angiography, the study investigated fractional myocardial mass, a concept of myocardial mass subtended by specific vessel, which could reduce anatomical-physiological mismatch. BACKGROUND: Discordance between anatomical stenosis and physiological severity is common but remains poorly understood. METHODS: This multicenter study enrolled 463 patients with 724 lesions, who underwent coronary computed tomography angiography (CCTA) and invasive coronary angiography with fractional flow reserve (FFR) measurement. FMM was assessed by allometric scaling analysis of arterial tree length and myocardial mass from CCTA. RESULTS: FFR <0.80, a criteria for vessel-specific physiological stenosis, was found in 281 vessels (39%). FMM decreased consistently according to the vessel downstream (p < 0.001, all). The frequency of FFR <0.80 increased in proportion to FMM and inverse proportion to angiographic minimal luminal diameter (MLD) (p < 0.001). In per-vessel analysis, FMM per MLD (FMM/MLD) showed good correlation with FFR (r = 0.61) and was superior to diameter stenosis (DS) for FFR <0.80 by receiver operating characteristic and reclassification analysis (C-statistics = 0.84 versus 0.74, net reclassification improvement [NRI] = 0.63, integrated discrimination improvement [IDI] = 0.18; p < 0.001, all). The optimal cutoff of FMM/MLD was 29 g/mm, with sensitivity = 75%, specificity = 77%, positive predictive value = 68%, negative predictive value = 83%, and accuracy = 77%. Addition of FMM/MLD to DS could further discriminate vessels with FFR <0.80 (C-statistic = 0.86 vs. 0.84, NRI = 0.34, IDI = 0.03; p < 0.005, all). In per-range classification analysis, agreement between FFR and FMM/MLD maintained >80% when the severity of disease was away from cutoff. CONCLUSIONS: FMM/MLD could find physiological severity of coronary artery with higher accuracy than anatomical stenosis. FMM may explain the anatomical-physiological discordance.
Authors: Michael Michail; Hakim-Moulay Dehbi; Nitesh Nerlekar; Justin E Davies; Andrew S P Sharp; Suneel Talwar; James D Cameron; Adam J Brown; Dennis T Wong; Anthony Mathur; Alun D Hughes; Om Narayan Journal: Catheter Cardiovasc Interv Date: 2019-01-02 Impact factor: 2.692