title: Viability assessment after conventional coronary angiography using a novel cardiovascular interventional therapeutic CT system: Comparison with gross morphology in a subacute infarct swine model.
abstract: BACKGROUND
  Given the lack of promptness and inevitable use of additional contrast agents, the myocardial viability imaging procedures have not been used widely for determining the need to performing revascularization.
  
  
  OBJECTIVE
  This study is aimed to evaluate the feasibility of myocardial viability assessment, consecutively with diagnostic invasive coronary angiography (ICA) without use of additional contrast agent, using a novel hybrid system comprising ICA and multislice CT (MSCT).
  
  
  METHODS
  In all, 14 Yucatan miniature swine models (female; age, 3 months; weight, 28-30 kg) were subjected to ICA followed by balloon occlusion (90 minutes) and reperfusion of the left anterior descending coronary artery. Two weeks after induction of myocardial infarction, delayed hyperenhancement (DHE) images were obtained, using a novel combined machine comprising ICA and 320-channel MSCT scanner (Aquilion ONE, Toshiba), after 2, 5, 7, 10, 15, and 20 minutes after conventional ICA. The heart was sliced in 10-mm consecutive sections in the short-axis plane and was embedded in a solution of 1% triphenyltetrazolium chloride (TTC). Infarct size was determined as TTC-negative areas as a percentage of total left ventricular area. On MSCT images, infarct size per slice was calculated by dividing the DHE area by the total slice area (%) and compared with histochemical analyses.
  
  
  RESULTS
  Serial MSCT scans revealed a peak CT attenuation of the infarct area (222.5 ± 36.5 Hounsfield units) with a maximum mean difference in CT attenuation between the infarct areas and normal myocardium of at 2 minutes after contrast injection (106.4; P for difference = 0.002). Furthermore, the percentage difference of infarct size by MSCT vs histopathologic specimen was significantly lower at 2 (8.5% ± 1.8%) and 5 minutes (9.5% ± 1.9%) than those after 7 minutes. Direct comparisons of slice-matched DHE area by MSCT demonstrated excellent correlation with TTC-derived infarct size (r = 0.952; P < .001). Bland-Altman plots of the differences between DHE by MSCT and TTC-derived infarct measurements plotted against their means showed good agreement between the 2 methods.
  
  
  CONCLUSIONS
  The feasibility of myocardial viability assessment by DHE using MSCT after conventional ICA was proven in experimental models, and the optimal viability images were obtained after 2 to 5 minutes after the final intracoronary injection of contrast agent for conventional ICA.
authors.affiliation: Brain Korea 21 Project for Medical Science, Yonsei University, Seoul, Korea.
authors.forename: Yeonggul
authors.initials: Y
authors.lastname: Jang
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Severance Cardiovascular Hospital, Yonsei University College of Medicine, 250 Seongsanno, Seodaemungu, Seoul 120-752, Korea.
authors.forename: Iksung
authors.initials: I
authors.lastname: Cho
authors.affiliation: Department of Radiology, New York-Presbyterian Hospital and the Weill Cornell Medical College, New York, NY, USA.|Section of Geriatrics, Department of Internal Medicine, Yale School of Medicine, Adler Geriatric Center, New Haven, CT, USA.
authors.forename: Bríain W Ó
authors.initials: BWÓ
authors.lastname: Hartaigh
authors.affiliation: Cardiovascular Product Evaluation Center, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Se-Il
authors.initials: SI
authors.lastname: Park
authors.affiliation: Brain Korea 21 Project for Medical Science, Yonsei University, Seoul, Korea.
authors.forename: Youngtaek
authors.initials: Y
authors.lastname: Hong
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Severance Cardiovascular Hospital, Yonsei University College of Medicine, 250 Seongsanno, Seodaemungu, Seoul 120-752, Korea.
authors.forename: Sanghoon
authors.initials: S
authors.lastname: Shin
authors.affiliation: Brain Korea 21 Project for Medical Science, Yonsei University, Seoul, Korea.
authors.forename: Seongmin
authors.initials: S
authors.lastname: Ha
authors.affiliation: Brain Korea 21 Project for Medical Science, Yonsei University, Seoul, Korea.
authors.forename: Byunghwan
authors.initials: B
authors.lastname: Jeon
authors.affiliation: Department of Computer Science and Engineering, Hankuk University of Foreign Studies, Kyonggi, 449-791, Korea.
authors.forename: Hoyup
authors.initials: H
authors.lastname: Jung
authors.affiliation: Cardiovascular Research Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Hackjoon
authors.initials: H
authors.lastname: Shim
authors.affiliation: Department of Radiology, New York-Presbyterian Hospital and the Weill Cornell Medical College, New York, NY, USA.
authors.forename: James K
authors.initials: JK
authors.lastname: Min
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Severance Cardiovascular Hospital, Yonsei University College of Medicine, 250 Seongsanno, Seodaemungu, Seoul 120-752, Korea.|Cardiovascular Research Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Hyuk-Jae
authors.initials: HJ
authors.lastname: Chang
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Severance Cardiovascular Hospital, Yonsei University College of Medicine, 250 Seongsanno, Seodaemungu, Seoul 120-752, Korea.
authors.forename: Yangsoo
authors.initials: Y
authors.lastname: Jang
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Severance Cardiovascular Hospital, Yonsei University College of Medicine, 250 Seongsanno, Seodaemungu, Seoul 120-752, Korea.|Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Namsik
authors.initials: N
authors.lastname: Chung
mesh_terms: D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage; D017023:Coronary Angiography / Q000379:methods*; D005260:Female; D061330:Multidetector Computed Tomography / Q000379:methods*; D064847:Multimodal Imaging / Q000379:methods*; D009203:Myocardial Infarction / Q000150:complications / Q000000981:diagnostic imaging* / Q000473:pathology; D017682:Myocardial Stunning / Q000000981:diagnostic imaging* / Q000209:etiology / Q000473:pathology; D015641:Radiography, Interventional / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013552:Swine; D014022:Tissue Survival
chemical_list: D003287:Contrast Media
keywords: Multislice computed tomography; Myocardial contrast delayed enhancement; Myocardial viability