Differentiation of total occlusion and high-grade stenosis in coronary CT angiography (original) (raw)
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European Journal of Radiology, 2015
Objectives: Coronary computed tomography angiography (CTA) allows the detection of obstructive coronary artery disease. However, its ability to predict the hemodynamic significance of stenoses is limited. We assessed differences in plaque characteristics and contrast density difference between hemodynamically significant and non-significant stenoses, as defined by invasive fractional flow reserve (FFR). Methods: Lesion characteristics of 59 consecutive patients (72 lesions) in whom invasive FFR was performed in at least one coronary artery with moderate to high-grade stenoses in coronary CTA were evaluated by two experienced readers. Coronary CTA data sets were acquired on a secondgeneration dual-source CT scanner using retrospectively ECG-gated spiral acquisition or prospectively ECG-triggered axial acquisition mode. Plaque volume and composition (non-calcified, calcified), remodeling index as well as contrast density difference (defined as the percentage decline in luminal CT attenuation/cross-sectional area over the lesion) were assessed using a semi-automatic software tool (Autoplaq). Additionally, the transluminal attenuation gradient (defined as the linear regression coefficient between intraluminal CT attenuation and length from the ostium) was determined. Differences in lesion characteristics between hemodynamically significant (invasively measured FFR ≤0.80) and non-significant lesions (FFR >0.80) were determined. Results: Mean patient age was 64 ± 11 years with 44 males (75%). 21 out of 72 coronary artery lesions (29%) were hemodynamically significant according to invasive FFR. Mean invasive FFR was 0.66 ± 0.12 vs. 0.91 ± 0.05 for hemodynamically significant versus non-significant lesions. Hemodynamically significant lesions showed a significantly greater percentage of non-calcified plaque compared to non-hemodynamically relevant lesions (51.3 ± 15.3% vs. 43.6 ± 16.5%, p = 0.021). Contrast density difference was significantly increased in hemodynamically relevant lesions (26.0 ± 20.2% vs. 16.6 ± 10.9% for non-significant lesions; p = 0.013). At a threshold of ≥24%, the contrast density difference predicted hemodynamically significant lesions with a specificity of 75%, sensitivity of 33%, PPV of 35% and NPV of 73%. The transluminal attenuation gradient showed no significant difference between hemodynamically significant and non-significant lesions (−1.4 ± 1.4 HU/mm vs. −1.1 ± 1.3 HU/mm, p = n.s.). Conclusions: Quantitative contrast density difference across coronary lesions in coronary CTA data sets may be applied as a non-invasive tool to identify hemodynamically significant stenoses.
Circulation: Cardiovascular Imaging, 2014
C omputed tomographic coronary angiography (CTCA) is a reliable, noninvasive imaging modality to visualize coronary artery disease with a high diagnostic accuracy compared with invasive coronary angiography (ICA). 1-3 In addition, CTCA can provide quantitative information of a coronary stenosis, similar to intravascular ultrasound (IVUS), cross-sectional information, and plaque burden. In daily practice, lesions with a diameter stenosis ≥50% on visual CTCA are generally considered for referral to ICA. However, similar to ICA, CTCA is an anatomic imaging technique; thus, it may result in both under-and overestimation of a lesion's severity and is often inaccurate in identifying functionally significant coronary lesions that cause ischemia. 4,5 Current guidelines suggest that treatment decisions based on the hemodynamic effect of a coronary lesion may improve clinical outcome. 6-8 Therefore, it would be relevant if quantitative parameters derived from CTCA could be optimized to predict the functional significance of a coronary stenosis. Background-Coronary lesions with a diameter narrowing ≥50% on visual computed tomographic coronary angiography (CTCA) are generally considered for referral to invasive coronary angiography. However, similar to invasive coronary angiography, visual CTCA is often inaccurate in detecting functionally significant coronary lesions. We sought to compare the diagnostic performance of quantitative CTCA with visual CTCA for the detection of functionally significant coronary lesions using fractional flow reserve (FFR) as the reference standard. Methods and Results-CTCA and FFR measurements were obtained in 99 symptomatic patients. In total, 144 coronary lesions detected on CTCA were visually graded for stenosis severity. Quantitative CTCA measurements included lesion length, minimal area diameter, % area stenosis, minimal lumen diameter, % diameter stenosis, and plaque burden [(vessel area−lumen area)/vessel area×100]. Optimal cutoff values of CTCA-derived parameters were determined, and their diagnostic accuracy for the detection of flow-limiting coronary lesions (FFR ≤0.80) was compared with visual CTCA. FFR was ≤0.80 in 54 of 144 (38%) coronary lesions. Optimal cutoff values to predict flow-limiting coronary lesion were 10 mm for lesion length, 1.8 mm 2 for minimal area diameter, 73% for % area stenosis, 1.5 mm for minimal lumen diameter, 48% for % diameter stenosis, and 76% for plaque burden. No significant difference in sensitivity was found between visual CTCA and quantitative CTCA parameters (P>0.05). The specificity of visual CTCA (42%; 95% confidence interval [CI], 31%-54%) was lower than that of minimal area diameter (68%; 95% CI, 57%-77%; P=0.001), % area stenosis (76%; 95% CI, 65%-84%; P<0.001), minimal lumen diameter (67%; 95% CI, 55%-76%; P=0.001), % diameter stenosis (72%; 95% CI, 62%-80%; P<0.001), and plaque burden (63%; 95% CI, 52%-73%; P=0.004). The specificity of lesion length was comparable with that of visual CTCA. Conclusions-Quantitative CTCA improves the prediction of functionally significant coronary lesions compared with visual CTCA assessment but remains insufficient. Functional assessment is still required in lesions of moderate stenosis to accurately detect impaired FFR.
To Study Coronary Artery Stenosis on CT in Comparison with Catheter Angiography
International Journal of Contemporary Medicine, Surgery and Radiology
MATERIAL AND METHODS This was a prospective study done from June 2012 to June 2014 in Sassoon general hospital. Sample size is 50 patients. Inclusion criteria: Patients coming for routine screening and getting CT coronary angiography (CTCA) and conventional angiography (CA) both.
The International Journal of Cardiovascular Imaging, 2013
To investigate the patterns and diagnostic implications of coronary arterial lesion calcification by CT angiography (CTA) using a novel, cross-sectional grading method, we studied 371 patients enrolled in the CorE-64 study who underwent CTA and invasive angiography for detecting coronary artery stenoses by quantitative coronary angiography (QCA). The number of quadrants involving calcium on a cross-sectional view for C30 and C50 % lesions in 4,511 arterial segments was assessed by CTA according to: noncalcified, mild (one-quadrant), moderate (two-quadrant), severe (three-quadrant) and very severe (four-quadrant calcium). Area under the receiver operating characteristic curve (AUC) were used to evaluate CTA diagnostic accuracy and agreement versus. QCA for plaque types. Only 4 % of C50 % stenoses by QCA were very severely calcified while 43 % were noncalcified. AUC for CTA to detect C50 % stenoses by QCA for non-calcified, mildly, moderately, severely, and very severely calcified plaques were 0.90, 0.88, 0.83, 0.76 and 0.89, respectively (P \ 0.05). In 198 lesions with severe calcification, the presence or absence of a visible residual lumen by CTA was associated with C50 % stenosis by QCA in 20.3 and 76.9 %, respectively. Kappa was 0.93 for interobserver variability in evaluating plaque calcification. We conclude that calcification of individual coronary artery lesions can be reliably graded using CTA. Most C50 % coronary artery stenoses are not or only mildly calcified. If no residual lumen is seen on CTA, calcified lesions are predictive of C50 % stenoses and vice versa. CTA diagnostic accuracy for detecting C50 % stenoses is reduced in lesions with more than mild calcification due to lower specificity.
Journal of Interventional Cardiology, 2014
Objectives: The purpose of this study was to evaluate the differences in the clinical and angiographic characteristics of chronic total occlusion (CTO) lesions among the 3 major coronary arteries (LAD, LCx, and RCA). Background: The success rate of percutaneous coronary intervention (PCI) of CTO lesions is not uniform among the 3 major coronary arteries and this may be influenced by the differences in angiographic and clinical characteristics that may exists between them. Methods: We retrospectively evaluated clinical and angiographic characteristics of patients who underwent PCI of CTO lesions at our 2 centers between 2003 and 2010. Results: We analyzed 708 CTO-PCI procedures between 2003 and 2010. The CTO lesions were located in LAD: 222 (31.4%), LCx: 167 (23.6%), and RCA: 319 (45.0%). Patients with CTO in LAD had lower incidence of previous history of PCI and CABG compared to those with CTO lesions in LCx or RCA. In regard to angiographic findings, LAD lesions tended to have more side branches and blunt occlusion stump. The LCx lesions presented more frequently as a part of multivessel disease. RCA lesions were significantly longer, more severely angulated, and calcified. Good collateral circulations were more often encountered in the RCA. In regard to success rates, RCA showed lower procedural success rates (71.8%) followed by LAD (74.8%) and LCx (79.0%). Conclusions: There were several differences in the clinical and angiographic characteristics of CTO lesions among the 3 major coronary arteries. These differences can explain the discrepancy in procedure success rates. (J Interven Cardiol 2014;27:44-49) Ã Fisher's exact test. LAD, left anterior descending artery; LCx, left circumflex artery; RCA, right coronary artery; SD, standard deviation; MI, myocardial infarction.