Noninvasive evaluation of coronary collateral arterial flow by coronary computed tomographic angiography.
BACKGROUND
Coronary collateral flow is an alternative source of myocardial perfusion in patients with totally occluded coronary arteries. Clinical evaluation of collateral flow has been limited by the need of invasive measurements. We investigated whether noninvasive coronary computed tomographic angiography can evaluate the angiographic extent of coronary collateral flow.


RESULTS
We enrolled 325 coronary computed tomographic angiography cases with angiographically confirmed chronic total occlusion (median age, 63 years; men 83%). Transluminal attenuation gradient (TAG), which reflects the kinetics of contrast media in coronary artery, of an entire artery as well as of a distal vessel was assessed to evaluate the flow in entire vessel and distal vessel. TAGs were validated against visually assessed angiographic collateral connection and Rentrop grading. TAG of an entire artery increased consistently according to the angiographic extent of collateral flow (P<0.001). Well-developed collaterals, defined by highest collateral connection and Rentrop grades (n=103), could be predicted by TAG of an entire artery (cutoff, ≥-7.6 Hounsfield units/10 mm; c-statistics, 0.72; sensitivity, 65%; specificity, 73%; positive predictive value, 52%; negative predictive value, 82%). TAG of a distal vessel could discriminate the antegrade (n=143) and retrograde (n=182) flows in distal artery (cutoff, 0.0 Hounsfield unit/10 mm; c-statistics, 0.88; sensitivity, 78%; specificity, 85%; positive predictive value, 87%; negative predictive value, 75%).


CONCLUSIONS
TAG, an intracoronary attenuation-based analysis of coronary computed tomographic angiography, moderately reflected the functional extent and direction of collateral flow.
From the Departments of Medicine (J.-H.C., E.K.K., Y.B.S., J-Y.H., S.H.C., H.-C.G., S.H.L., J.K.O.), Emergency Medicine (J.-H.C.), and Radiology (S.M.K., Y.H.C.), Cardiovascular Imaging Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea; and Department of Internal Medicine, Mayo Clinic College of Medicine, Rochester, MN (J.K.O.). jhchoimd@gmail.com.
Jin-Ho
JH
Choi
From the Departments of Medicine (J.-H.C., E.K.K., Y.B.S., J-Y.H., S.H.C., H.-C.G., S.H.L., J.K.O.), Emergency Medicine (J.-H.C.), and Radiology (S.M.K., Y.H.C.), Cardiovascular Imaging Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea; and Department of Internal Medicine, Mayo Clinic College of Medicine, Rochester, MN (J.K.O.).
Eun Kyoung
EK
Kim
From the Departments of Medicine (J.-H.C., E.K.K., Y.B.S., J-Y.H., S.H.C., H.-C.G., S.H.L., J.K.O.), Emergency Medicine (J.-H.C.), and Radiology (S.M.K., Y.H.C.), Cardiovascular Imaging Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea; and Department of Internal Medicine, Mayo Clinic College of Medicine, Rochester, MN (J.K.O.).
Sung Mok
SM
Kim
From the Departments of Medicine (J.-H.C., E.K.K., Y.B.S., J-Y.H., S.H.C., H.-C.G., S.H.L., J.K.O.), Emergency Medicine (J.-H.C.), and Radiology (S.M.K., Y.H.C.), Cardiovascular Imaging Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea; and Department of Internal Medicine, Mayo Clinic College of Medicine, Rochester, MN (J.K.O.).
Young Bin
YB
Song
From the Departments of Medicine (J.-H.C., E.K.K., Y.B.S., J-Y.H., S.H.C., H.-C.G., S.H.L., J.K.O.), Emergency Medicine (J.-H.C.), and Radiology (S.M.K., Y.H.C.), Cardiovascular Imaging Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea; and Department of Internal Medicine, Mayo Clinic College of Medicine, Rochester, MN (J.K.O.).
Joo-Yong
JY
Hahn
From the Departments of Medicine (J.-H.C., E.K.K., Y.B.S., J-Y.H., S.H.C., H.-C.G., S.H.L., J.K.O.), Emergency Medicine (J.-H.C.), and Radiology (S.M.K., Y.H.C.), Cardiovascular Imaging Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea; and Department of Internal Medicine, Mayo Clinic College of Medicine, Rochester, MN (J.K.O.).
Seung Hyuk
SH
Choi
From the Departments of Medicine (J.-H.C., E.K.K., Y.B.S., J-Y.H., S.H.C., H.-C.G., S.H.L., J.K.O.), Emergency Medicine (J.-H.C.), and Radiology (S.M.K., Y.H.C.), Cardiovascular Imaging Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea; and Department of Internal Medicine, Mayo Clinic College of Medicine, Rochester, MN (J.K.O.).
Hyeon-Cheol
HC
Gwon
From the Departments of Medicine (J.-H.C., E.K.K., Y.B.S., J-Y.H., S.H.C., H.-C.G., S.H.L., J.K.O.), Emergency Medicine (J.-H.C.), and Radiology (S.M.K., Y.H.C.), Cardiovascular Imaging Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea; and Department of Internal Medicine, Mayo Clinic College of Medicine, Rochester, MN (J.K.O.).
Sang Hoon
SH
Lee
From the Departments of Medicine (J.-H.C., E.K.K., Y.B.S., J-Y.H., S.H.C., H.-C.G., S.H.L., J.K.O.), Emergency Medicine (J.-H.C.), and Radiology (S.M.K., Y.H.C.), Cardiovascular Imaging Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea; and Department of Internal Medicine, Mayo Clinic College of Medicine, Rochester, MN (J.K.O.).
Yeon Hyeon
YH
Choe
From the Departments of Medicine (J.-H.C., E.K.K., Y.B.S., J-Y.H., S.H.C., H.-C.G., S.H.L., J.K.O.), Emergency Medicine (J.-H.C.), and Radiology (S.M.K., Y.H.C.), Cardiovascular Imaging Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea; and Department of Internal Medicine, Mayo Clinic College of Medicine, Rochester, MN (J.K.O.).
Jae K
JK
Oh
D003097:Collateral Circulation / Q000502:physiology*; D003287:Contrast Media; D017023:Coronary Angiography / Q000379:methods*; D003326:Coronary Circulation / Q000502:physiology*; D003331:Coronary Vessels / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007479:Iopamidol / Q000031:analogs & derivatives; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011856:Radiographic Image Enhancement / Q000379:methods; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
D003287:Contrast Media; C057937:iomeprol; D007479:Iopamidol
collateral circulation; coronary artery disease; multidetector computed tomography