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Background: Computed tomography coronary angiography (CTA) can be used for assessment of plaque characteristics; however, quantitative assessment of changes in plaque composition in response to LDL lowering has not been performed with CTA. We sought to assess the association between LDL reduction and changes in plaque composition with quantitative CTA., Methods: Quantification of total, calcified, non-calcified and low-density non-calcified plaque volumes (TPV, CPV, NCPV and LD-NCPV) was performed using semi-automated software in 234 vessels from 116 consecutive patients (89 men, 60 ± 10 years) with baseline LDL>70 mg/dl. Significant reduction in LDL was defined as a decrease by >10% of baseline LDL. Changes (Δ) in plaque volumes between the second and baseline study were compared between patients with LDL reduction (n = 63) and those with no decrease in LDL (n = 53)., Results: Median LDL at baseline was 98 mg/dl [interquartile range (IQR) 83-119 mg/dl] and median ΔLDL was -14 mg/dl (IQR -38 to 3 mg/dl). Mean interval between sequential CTA was 3.5 ± 1.6 years. TPV, NCPV, and LD-NCPV decreased in patients with a reduction in LDL compared to baseline; whereas, patients without reduction in LDL experienced an increase in TPV, NCPV and LD-NCPV. After adjusting for age, statin use, diabetes, baseline LDL and baseline TPV, reduction in LDL was associated with a decrease in TPV (P = 0.005), NCPV (P = 0.002) and LD-NCPV (P = 0.011) compared to patients without a reduction in LDL., Conclusion: Reduction in LDL was associated with beneficial changes in the amount and composition of noncalcified plaque as measured using semi-automated quantitative software by CTA., (Copyright © 2018 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.)

Aims: Non-invasive fractional flow reserve derived from coronary CT angiography (FFR CT ) has been shown to be predictive of lesion-specific ischemia as assessed by invasive fractional flow reserve (FFR). However, in practice, clinicians are often faced with an abnormal distal FFR CT in the absence of a discrete obstructive lesion. Using quantitative plaque analysis, we sought to determine the relationship between an abnormal whole vessel FFR CT (V-FFR CT ) and quantitative measures of whole vessel atherosclerosis in coronary arteries without obstructive stenosis., Methods: FFR CT was calculated in 155 consecutive patients undergoing coronary CTA with ≥25% but less than 70% stenosis in at least one major epicardial vessel. Semi-automated software was used to quantify plaque volumes (total plaque [TP], calcified plaque [CP], non-calcified plaque [NCP], low-density non-calcified plaque [LD-NCP]), remodeling index [RI], maximal contrast density difference [CDD] and percent diameter stenosis [%DS]. Abnormal V-FFR CT was defined as a minimum value of ≤0.75 across the vessel (at the most distal region where FFR CT was computed)., Results: Vessels with abnormal V-FFR CT had higher per-vessel TP (554 vs 331 mm 3 ), CP (59 vs 25 mm 3 ), NCP (429 vs 295 mm 3 ), LD-NCP (65 vs 35 mm 3 ) volume and maximum CDD (21 vs 14%) than those with normal V-FFR CT (median, p < 0.05 for all). Using a multivariate analysis to adjust for CDD and %DS, all measures of plaque volume were predictive of abnormal V-FFR CT (OR 2.09, 1.36, 1.95, 1.95 for TP, CP, NCP and LD-NCP volume, respectively; p < 0.05 for all)., Conclusion: Abnormal V-FFR CT in vessels without obstructive stenosis is associated with multiple markers of diffuse non-obstructive atherosclerosis, independent of stenosis severity. Whole vessel FFR CT may represent a novel measure of diffuse coronary plaque burden., (Copyright © 2018. Published by Elsevier Inc.)

Background: Epicardial adipose tissue (EAT) volume is associated with plaque formation and cardiovascular event risk, its density may reflect tissue composition and metabolic activity., Objectives: Global and regional associations between EAT volume and density, ischemia and coronary calcium were investigated using a novel automatic quantitative measurement software., Methods: 71 patients with an intermediate pre-test probability for coronary artery disease and inducible ischemia by SPECT were matched to two same-gender controls (total of 213 patients, 90% male, age 60 ± 10 years). Non-contrast CT for assessment of EAT volume, density (in Hounsfield Unit [HU]) and coronary calcium score (CCS) was performed., Results: Global EAT volume was significantly increased in ischemic patients compared to controls (96 ± 49 vs. 82 ± 36 cm(3), p = 0.04), density showed no significant difference (-75.6 ± 4.3 vs. -75.1 ± 4.1HU, p = 0.63). EAT volume and density differed significantly between coronary territories (LAD: 37 ± 18 cm(3), -77.8 ± 4.5HU; LCx: 16 ± 9 cm(3), -73.9 ± 4.1HU; RCA: 36 ± 17 cm(3), -71.7 ± 4.8HU, p < 0.001). For regional ischemia, only LCx territory showed a significantly higher EAT volume (18 ± 8 vs. 16 ± 9 cm(3), p = 0.048). Multivariable logistic regression revealed a significant association with ischemia for EAT volume (OR 2.09 (1.0; 4.3), p = 0.049) and CCS (OR 1.43 (1.1; 1.9), p = 0.006). EAT volume significantly improved discrimination of ischemia over CCS (Integrated Discrimination Improvement: 3.5%, 95%CI: 1.1-6.1%, p = 0.004). Hypertension was the only risk factor significantly influencing EAT volume and density (98 ± 48 vs. 78 ± 31 cm(3), p = 0.002, -76.0 ± 4.1 vs. -74.5 ± 4.1 HU, p = 0.01)., Conclusions: EAT volume is associated with myocardial ischemia and improves the discriminative power for independent ischemia prediction over CCS. In hypertensive patients, EAT is characterized by lower density and higher volumes., (Copyright © 2016 Society of Cardiovascular Computed Tomography. All rights reserved.)

Background: Patients with severe mitral regurgitation may be screened for coronary artery disease with the use of cardiac computed tomography before valve surgery., Objective: We hypothesized that dual-source multidetector computed tomography (DSCT) could effectively predict the culprit mitral valve scallop identified during surgery among patients with degenerative mitral valve disease undergoing surgical mitral valve repair., Methods: Twenty-six patients (7 women) with known severe mitral regurgitation underwent elective mitral valve repair from September 2006 through December 2009 at our institution. An additional 10 patients underwent aortic valve replacement and had no documented history of mitral valve disease. All patients underwent transthoracic echocardiography and had retrospectively gated DSCT performed to evaluate the coronary arteries before surgery. Each mitral scallop was identified as either normal, prolapsed, or flail. CT findings were compared with operative findings, which were guided by intraoperative transesophageal echocardiography (TEE)., Results: In the 26 patients examined, DSCT identified flail in 23 scallops and prolapse in 48. DSCT agreed with operative findings on identification of the culprit scallop in 25 of 26 patients. On a per-patient and per-scallop basis, the observed κ statistic for agreement between DSCT and operative findings was 0.82. Of the 60 scallops in the aortic valve group, all were judged to be normal by both DSCT and TEE., Conclusions: In patients with degenerative mitral valve disease undergoing cardiac surgery, DSCT demonstrates excellent agreement with intraoperative findings. DSCT can be used to identify the affected mitral valve scallop and its structure in patients who are candidates for mitral valve repair., (Copyright © 2012 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.)

Background: Strategies to reduce the radiation dose of coronary computed tomography angiography (CCTA), while maintaining diagnostic image quality, are imperative for cardiac CT., Objective: We aimed to reduce radiation dose during helical dual-source CCTA by combining lower tube voltage, shortest possible full tube current (FTC) window, and minimal tube current outside the FTC window, and to develop a patient-based algorithm for applying these dose-reduction components., Methods: We compared FTC at 70% of the cardiac cycle (FTC70) to a 45% to 75% window (FTC45-75) using both 100 and 120 kVp (N=118). FTC70 was used in patients with heart rates <70 beats/min, no arrhythmia, age <65 years; 100 kVp was used in patients with body mass index (BMI) <30, a low coronary calcium score (CCS), and no stents. Objective and subjective image quality were assessed., Results: Compared with FTC45-75 at 120 kVp, radiation dose was reduced by 66% for FTC70 at 100 kVp (mean radiation dose: 4.4 +/- 0.9 mSv) and by 43% for FTC70 at 120 kVp. 99% of 780 segments in the FTC70 group were of diagnostic quality. Noise, signal-to-noise ratio, and contrast-to-noise ratio were comparable between FTC70 and FTC45-75 for both 100 and 120 kVp. BMI, CCS and maximal heart rate variation were predictors of image quality. Tube voltage, FTC window width, scan length, and average heart rate were predictors of radiation dose., Conclusions: A successful patient-based algorithm for radiation dose reduction during helical CCTA using DSCT has been developed and validated in clinical practice.

Background: Prospectively gated coronary computed tomographic angiography (CCTA) with dual-source CT allows substantial reduction of radiation exposure but requires prospective single-phase selection and assessment of likelihood of adequate image quality., Objective: We developed and tested the model for predicting success of prospectively gated CCTA., Methods: Retrospectively gated CCTA was acquired with dual-source CT in 162 patients. Two cardiologists assessed by consensus whether diagnostic quality images could have been obtained in a single predefined phase, 70% of R-R interval (70P), thereby identifying patients in whom a prospectively gated scan at 70P would have been successful. Logistic regression models were built with and without a coronary calcium scan. The obtained criteria were applied on 42 additional patients., Results: By logistic regression, heart rate before CCTA of >or=70 beats/min, maximal heart rate variation before CCTA of >or=10 beats/min, coronary calcium score >or= 400 U, and body mass index (in kg/m(2)) >or= 30 were independent predictors of unsuccessful prospectively gated CCTA using 70P. Excluding coronary calcium score from the model, these same variables in addition to age > 65 years were found to be predictors of unsuccessful prospectively gated CCTA. Applying this model to 42 additional patients, using prospective gating, only 5 segments in 4 patients were nondiagnostic. Mean radiation dose for prospectively gated CCTA was 2.2 +/- 0.8 mSv., Conclusion: Prospectively gated CCTA with dual-source CT can be successfully implemented with consideration of prescan heart rate, heart rate variability, body mass index, and coronary calcium score.