Stress Myocardial Blood Flow Ratio by Dynamic CT Perfusion Identifies Hemodynamically Significant CAD

• Published in: JACC. Cardiovascular imaging 2020-04, Vol.13 (4), p.966-976
• Main Authors: Yang, Junjie, Dou, Guanhua, He, Bai, Jin, Qinhua, Chen, Zhiye, Jing, Jing, Di Carli, Marcelo F., Chen, Yundai, Blankstein, Ron
• Format: Article
• Language: English
• Subjects: Aged; Cardiac Catheterization; Computed Tomography Angiography; Coronary Angiography; Coronary Artery Disease - diagnostic imaging; Coronary Artery Disease - physiopathology; Coronary Stenosis - diagnostic imaging; Coronary Stenosis - physiopathology; Female; Fractional Flow Reserve, Myocardial; hemodynamically myocardial ischemia; Hemodynamics; Humans; Male; Middle Aged; multislice computed tomography; myocardial perfusion; Myocardial Perfusion Imaging; noninvasive imaging; Predictive Value of Tests; Prospective Studies; Severity of Illness Index
• ISSN: 1936-878X; 1876-7591
• DOI: 10.1016/j.jcmg.2019.06.016

The aim of this study was to evaluate the diagnostic accuracy of stress myocardial blood flow ratio (SFR), a novel parameter derived from stress dynamic computed tomographic perfusion (CTP), for the detection of hemodynamically significant coronary stenosis. A comprehensive cardiac computed tomographic protocol combining coronary computed tomographic angiography (CTA) and CTP can provide a simultaneous assessment of both coronary artery anatomy and ischemia. Patients with chest pain scheduled for invasive angiography were prospectively enrolled in this study. Stress dynamic CTP was performed followed by coronary CTA using a second-generation dual-source computed tomographic system. At subsequent invasive angiography, fractional flow reserve was performed to identify hemodynamically significant stenosis. For each coronary territory, SFR was defined as the ratio of hyperemic myocardial blood flow (MBF) in an artery with stenosis to hyperemic MBF in a nondiseased artery. The diagnostic accuracy of SFR to identify hemodynamically significant stenosis was determined against the reference standard of invasive fractional flow reserve ≤0.80. A total of 82 patients (mean age 58.5 ± 10 years) with 101 vessels with either 1- or 2-vessel disease were included. By FFR, 48 (47.5%) vessels were deemed hemodynamically significant. Hyperemic MBF and SFR were lower for vessels with hemodynamically significant lesions (95.1 ± 32.4 ml/100 ml/min vs. 142.5 ± 31.2 ml/100 ml/min and 0.66 ± 0.14 vs. 0.90 ± 0.07, respectively; p