Novel Approaches for the Use of Cardiac/Coronary Computed Tomography Angiography

Recent developments in the novel imaging technology of cardiac computed tomography (CT) not only permit detailed assessment of cardiac anatomy but also provide insight into cardiovascular physiology. Foremost, coronary CT angiography (CCTA) enables direct noninvasive examination of both coronary artery stenoses and atherosclerotic plaque characteristics. Calculation of computational fluid dynamics by cardiac CT allows the noninvasive estimation of fractional flow reserve, which increases the diagnostic accuracy for detection of hemodynamically significant coronary artery disease. In addition, a combination of myocardial CT perfusion and CCTA can provide simultaneous anatomical and functional assessment of coronary artery disease. Finally, detailed anatomical evaluation of atrial, ventricular, and valvular anatomy provides diagnostic information and guidance for procedural planning, such as for transcatheter aortic valve replacement. The clinical applications of cardiac CT will be extended with the development of these novel modalities

Novel Approaches for the Use of Cardiac/Coronary Computed Tomography Angiography

Recent developments in the novel imaging technology of cardiac computed tomography (CT) not only permit detailed assessment of cardiac anatomy but also provide insight into cardiovascular physiology. Foremost, coronary CT angiography (CCTA) enables direct noninvasive examination of both coronary artery stenoses and atherosclerotic plaque characteristics. Calculation of computational fluid dynamics by cardiac CT allows the noninvasive estimation of fractional flow reserve, which increases the diagnostic accuracy for detection of hemodynamically significant coronary artery disease. In addition, a combination of myocardial CT perfusion and CCTA can provide simultaneous anatomical and functional assessment of coronary artery disease. Finally, detailed anatomical evaluation of atrial, ventricular, and valvular anatomy provides diagnostic information and guidance for procedural planning, such as for transcatheter aortic valve replacement. The clinical applications of cardiac CT will be extended with the development of these novel modalities

Quantitative measurement of lipid rich plaque by coronary computed tomography angiography: A correlation of histology in sudden cardiac death

© 2018 Background and aims: Recent advancements in coronary computed tomography angiography (CCTA) have allowed for the quantitative measurement of high-risk lipid rich plaque. Determination of the optimal threshold for Hounsfield units (HU) by CCTA for identifying lipid rich plaque remains unknown. We aimed to validate reliable cut-points of HU for quantitative assessment of lipid rich plaque. Methods: 8 post-mortem sudden coronary death hearts were evaluated with CCTA and histologic analysis. Quantitative plaque analysis was performed in histopathology images and lipid rich plaque area was defined as intra-plaque necrotic core area. CCTA images were analyzed for quantitative plaque measurement. Low attenuation plaque (LAP) was defined as any pixel \u3c 30, 45, 60, 75, and 90 HU cut-offs within a coronary plaque. The area of LAP was calculated in each cross-section. Results: Among 105 cross-sections, 37 (35.2%) cross-sectional histology images contained lipid rich plaque. Although the highest specificity for identifying lipid rich plaque was shown with \u3c30 HU cut-off (88.2%), sensitivity (e.g. 55.6% for \u3c75 HU, 16.2% for \u3c30 HU) and negative predictive value (e.g. 75.9% for \u3c75 HU, 65.9% for \u3c30 HU) tended to increase with higher HU cut-offs. For quantitative measurement, \u3c75 HU showed the highest correlation coefficient (0.292, p = 0.003) and no significant differences were observed between lipid rich plaque area and LAP area between histology and CT analysis (Histology: 0.34 ± 0.73 mm 2 , QCT: 0.37 ± 0.71 mm 2 , p = 0.701). Conclusions: LAP area by CCTA using a \u3c75 HU cut-off value demonstrated high sensitivity and quantitative agreement with lipid rich plaque area by histology analysis

The Predictive Value of Coronary Artery Calcium Scoring for Major Adverse Cardiac Events According to Renal Function (from the Coronary Computed Tomography Angiography Evaluation for Clinical Outcomes: An International Multicenter [CONFIRM] Registry)

The prognostic performance of coronary artery calcium score (CACS) for predicting adverse outcomes in patients with decreased renal function remains unclear. We aimed to examine whether CACS improves risk stratification by demonstrating incremental value beyond a traditional risk score according to renal function status. 9,563 individuals without known coronary artery disease were enrolled. Estimated glomerular filtration rate (eGFR, ml/min/1.73 m) was ascertained using the modified Modification of Diet in Renal Disease formula, and was categorized as: ≥90, 60 to 89, and 400. Multivariable Cox regression was used to estimate hazard ratios (HR) with 95% confidence intervals (95% CI) for major adverse cardiac events (MACE), comprising all-cause mortality, myocardial infarction, and late revascularization (>90 days). Mean age was 55.8 ± 11.5 years (52.8% male). In total, 261 (2.7%) patients experienced MACE over a median follow-up of 24.5 months (interquartile range: 16.9 to 41.1). Incident MACE increased with higher CACS across each eGFR category, with the highest rate observed among patients with CACS >400 and eGFR 400 increased MACE risk with HR 4.46 (95% CI 1.68 to 11.85), 6.63 (95% CI 4.03 to 10.92), and 6.14 (95% CI 2.85 to 13.21) for eGFR ≥90, 60 to 89, and <60, respectively, as compared with CACS 0. Further, CACS improved discrimination and reclassification beyond Framingham 10-year risk score (FRS) (AUC: 0.70 vs 0.64; category free-NRI: 0.51, all p <0.001) for predicting MACE in patients with impaired renal function (eGFR < 90). In conclusion, CACS improved risk stratification and provided incremental value beyond FRS for predicting MACE, irrespective of eGFR status