Contrast-enhanced multidetector computed tomography viability imaging after myocardial infarction : Characterization of myocyte death, microvascular obstruction, and chronic scar

• Published in: Circulation (New York, N.Y.) Vol. 113; no. 3; pp. 394 - 404
• Main Authors: LARDO, Albert C, CORDEIRO, Marco A. S, HALPERIN, Henry R, WU, Katherine C, HARE, Joshua M, LIMA, Joao A. C, SILVA, Caterina, AMADO, Luciano C, GEORGE, Richard T, SALIARIS, Anastasios P, SCHULERI, Karl H, FERNANDES, Veronica R, ZVIMAN, Menekhem, NAZARIAN, Saman
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD Lippincott Williams & Wilkins 24.01.2006
• Subjects: Acute Disease; Animals; Biological and medical sciences; Blood and lymphatic vessels; Cardiology. Vascular system; Cell Death; Chronic Disease; Cicatrix - diagnostic imaging; Cicatrix - pathology; Contrast Media; Coronary Angiography; Coronary Circulation; Coronary heart disease; Disease Models, Animal; Diseases of the peripheral vessels. Diseases of the vena cava. Miscellaneous; Dogs; Heart; Medical sciences; Microcirculation; Myocardial Infarction - diagnostic imaging; Myocardial Infarction - pathology; Myocytes, Cardiac - pathology; Neurology; Swine; Tomography Scanners, X-Ray Computed; Tomography, X-Ray Computed - instrumentation; Tomography, X-Ray Computed - methods; Triiodobenzoic Acids; Vascular diseases and vascular malformations of the nervous system; Myocardial infarction; Scar; Cardiovascular disease; Myocardial disease; Obstruction; imaging; Myocyte; Chronic; Multidetector scanner; Heart disease; heart diseases; Tomography; Computerized axial tomography; Contrast media
• ISSN: 0009-7322; 1524-4539
• DOI: 10.1161/CIRCULATIONAHA.105.521450

The ability to distinguish dysfunctional but viable myocardium from nonviable tissue has important prognostic implications after myocardial infarction. The purpose of this study was to validate the accuracy of contrast-enhanced multidetector computed tomography (MDCT) for quantifying myocardial necrosis, microvascular obstruction, and chronic scar after occlusion/reperfusion myocardial infarction. Ten dogs and 7 pigs underwent balloon occlusion of the left anterior descending coronary artery (LAD) followed by reperfusion. Contrast-enhanced (Visipaque, 150 mL, 325 mg/mL) MDCT (0.5 mm x 32 slice) was performed before occlusion and 90 minutes (canine) or 8 weeks (porcine) after reperfusion. MDCT images were analyzed to define infarct size/extent and microvascular obstruction and compared with postmortem myocardial staining (triphenyltetrazolium chloride) and microsphere blood flow measurements. Acute and chronic infarcts by MDCT were characterized by hyperenhancement, whereas regions of microvascular obstruction were characterized by hypoenhancement. MDCT infarct volume compared well with triphenyltetrazolium chloride staining (acute infarcts 21.1+/-7.2% versus 20.4+/-7.4%, mean difference 0.7%; chronic infarcts 4.15+/-1.93% versus 4.92+/-2.06%, mean difference -0.76%) and accurately reflected morphology and the transmural extent of injury in all animals. Peak hyperenhancement of infarcted regions occurred approximately 5 minutes after contrast injection. MDCT-derived regions of microvascular obstruction were also identified accurately in acute studies and correlated with reduced flow regions as measured by microsphere blood flow. The spatial extent of acute and healed myocardial infarction can be determined and quantified accurately with contrast-enhanced MDCT. This feature, combined with existing high-resolution MDCT coronary angiography, may have important implications for the comprehensive assessment of cardiovascular disease.