Comparison of quantitative atherosclerotic plaque burden from coronary CT angiography in patients with first acute coronary syndrome and stable coronary artery disease

BackgroundCoronary CTA allows characterization of non-calcified and calcified plaque and identification of high-risk plaque features.ObjectiveWe aimed to quantitatively characterize and compare coronary plaque burden from CTA in patients with a first acute coronary syndrome (ACS) and controls with stable coronary artery disease.Materials and methodsWe retrospectively analyzed consecutive patients with non-ST-segment elevation myocardial infarction (NSTEMI) or unstable angina with a first ACS, who underwent CTA as part of their initial workup before invasive coronary angiography and age- and gender-matched controls with stable chest pain; controls also underwent CTA with subsequent invasive angiography (total n = 28). Culprit arteries were identified in ACS patients. Coronary arteries were analyzed by automated software to quantify calcified plaque (CP), noncalcified plaque (NCP), and low-density NCP (LD-NCP, attenuation <30 Hounsfield units) volumes, and corresponding burden (plaque volume × 100%/vessel volume), stenosis, remodeling index, contrast density difference (maximum percent difference in attenuation/cross-sectional area from proximal cross-section), and plaque length.ResultsACS patients had fewer lesions (median, 1), with higher total NCP and LD-NCP burdens (NCP: 57.4% vs 41.5%; LD-NCP: 12.5% vs 8%; P ≤ .04), higher maximal stenoses (85.6% vs 53.0%; P = .003) and contrast density differences (46.1 vs 16.3%; P < .006). Per-patient CP burden was not different between ACS and controls. NCP and LD-NCP plaque burden was higher in culprit vs nonculprit arteries (NCP: 57.8% vs 9.5%; LD-NCP: 8.4% vs 0.6%; P ≤ .0003); CP was not significantly different. Culprit arteries had increased plaque lengths, remodeling indices, stenoses, and contrast density differences (46.1% vs 10.9%; P ≤ .001).ConclusionNoninvasive quantitative coronary artery analysis identified several differences for ACS, both on per-patient and per-vessel basis, including increased NCP, LD-NCP burden, and contrast density difference.     

Relationship of low- and high-density lipoproteins to coronary artery plaque composition by CT angiography

BackgroundThe association between lipoprotein levels and coronary plaque composition is not well understood.ObjectiveThe aim of this prospective international multicenter study of statin-naive individuals was to evaluate the association of low-density lipoprotein (LDL), high-density lipoprotein (HDL), and total cholesterol (TC) to coronary plaque composition by coronary computed tomographic angiography (CTA).MethodsWe studied 4575 individuals without known coronary artery disease not taking statin medications who underwent coronary CTA. Comparisons were made between those with high versus low LDL, HDL, TC, and non-HDL. We assessed the relationship of lipoproteins and plaques of specific composition (noncalcified [NCP], partially calcified [PCP], or calcified [CP] plaque).ResultsMean age was 57 ± 11 years (55% men). In univariable analyses, high LDL, low HDL, high TC, and high non-HDL were each associated with increased prevalence of NCPs, PCPs, and CPs (P < 0.05 for all). In multivariable analyses, high non-HDL was associated with the presence of NCP (odds ratio, 1.47; 95% CI, 1.22–1.78: P < 0.001). In the further subanalysis, a weak relationship between the highest group of non HDL (≥190 mg/dL) and the presence of CP was also noted (odds ratio, 1.33; 95% CI, 1.01–1.76; P = 0.04). Further, high non-HDL was associated with increasing numbers of segments with NCP (β coefficient, 0.043; 95% CI, 0.021–0.065; P < 0.001) but not segments with PCP or CP.ConclusionNCP presence and extent are associated with high non-HDL. These results suggest a relationship between lipid profile and plaque composition.     

Interscan reproducibility of quantitative coronary plaque volume and composition from CT coronary angiography using an automated method

Objectives

Quantitative measurements of coronary plaque volume may play a role in serial studies to determine disease progression or regression. Our aim was to evaluate the interscan reproducibility of quantitative measurements of coronary plaque volumes using a standardized automated method.

Methods

Coronary dual source computed tomography angiography (CTA) was performed twice in 20 consecutive patients with known coronary artery disease within a maximum time difference of 100 days. The total plaque volume (TP), the volume of non-calcified plaque (NCP) and calcified plaque (CP) as well as the maximal remodelling index (RI) were determined using automated software.

Results

Mean TP volume was 382.3?±?236.9 mm³ for the first and 399.0?±?247.3 mm³ for the second examination (p?=?0.47). There were also no significant differences for NCP volumes, CP volumes or RI. Interscan correlation of the plaque volumes was very good (Pearson’s correlation coefficients: r?=?0.92, r?=?0.90 and r?=?0.96 for TP, NCP and CP volumes, respectively).

Conclusions

Automated software is a time-saving method that allows accurate assessment of coronary atherosclerotic plaque volumes in coronary CTA with high reproducibility. With this approach, serial studies appear to be possible.

Key Points

? Reproducibility of coronary atherosclerotic plaque volume in coronary CTA is high. ? Using automated software facilitates quantitative measurements. ? Serial studies to determine progression or regression of coronary plaque are possible.     

A cross-sectional survey of coronary plaque composition in individuals on non-statin lipid lowering drug therapies and undergoing coronary computed tomography angiography

IntroductionNon-statin therapy (NST) is used as second-line treatment when statin monotherapy is inadequate or poorly tolerated.ObjectiveTo determine the association of NST with plaque composition, alone or in combination with statins, in patients undergoing coronary computed tomography angiography (coronary CTA).MethodsFrom the multicenter CONFIRM registry, we analyzed individuals who underwent coronary CTA with known lipid-lowering therapy status and without prior coronary artery disease at baseline. We created a propensity score for being on NST, followed by stepwise multivariate linear regression, adjusting for the propensity score as well as risk factors, to determine the association between NST and the number of coronary artery segments with each plaque type (non-calcified (NCP), partially calcified (PCP) or calcified (CP)) and segment stenosis score (SSS).ResultsOf the 27,125 subjects in CONFIRM, 4,945 met the inclusion criteria; 371 (7.5%) took NST. At baseline, patients on NST had more prevalent risk factors and were more likely to be on concomitant cardiac medications. After multivariate and propensity score adjustment, NST was not associated with plaque composition: NCP (0.07 increase, 95% CI: −0.05, 0.20; p = 0.26), PCP (0.10 increase, 95% CI: −0.10, 0.31; p = 0.33), CP (0.18 increase, 95% CI: −0.10, 0.46; p = 0.21) or SSS (0.45 increase, 95% CI: −0.02,0.93; p = 0.06). The absence of an effect of NST on plaque type was not modified by statin use (p for interaction > 0.05 for all).ConclusionIn this cross-sectional study, non-statin therapy was not associated with differences in plaque composition as assessed by coronary CTA.     

Non-invasive fractional flow reserve in vessels without severe obstructive stenosis is associated with coronary plaque burden

AimsNon-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.MethodsFFR_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).ResultsVessels with abnormal V-FFR_CT had higher per-vessel TP (554 vs 331 mm³), CP (59 vs 25 mm³), NCP (429 vs 295 mm³), LD-NCP (65 vs 35 mm³) 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).ConclusionAbnormal 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.     

Repeatability of quantitative pericoronary adipose tissue attenuation and coronary plaque burden from coronary CT angiography

BackgroundHigh pericoronary adipose tissue (PCAT) attenuation and non-calcified plaque burden (NCP) measured from coronary CT angiography (CTA) have been implicated in future cardiac events. We aimed to evaluate the interobserver and intraobserver repeatability of PCAT attenuation and NCP burden measurement from CTA, in a sub-study of the prospective SCOT-HEART trial.MethodsFifty consecutive CTAs from participants of the CT arm of the prospective SCOT-HEART trial were included. Two experienced observers independently measured PCAT attenuation and plaque characteristics throughout the whole coronary tree from CTA using semi-automatic quantitative software.ResultsWe analyzed proximal segments in 157 vessels. Intraobserver mean differences in PCAT attenuation and NCP plaque burden were ?0.05HU and 0.92% with limits of agreement (LOA) of ±1.54 and ± 5.97%. Intraobserver intraclass correlation coefficients (ICC) for PCAT attenuation and NCP burden were excellent (0.999 and 0.978). Interobserver mean differences in PCAT attenuation and NCP plaque burden were 0.13HU [LOA ±1.67HU] and ?0.23% (LOA ±9.61%). Interobserver ICC values for PCAT attenuation and NCP burden were excellent (0.998 and 0.944).ConclusionPCAT attenuation and NCP burden on CTA has high intraobserver and interobserver repeatability, suggesting they represent a repeatable and robust method of quantifying cardiovascular risk.     

Comparison of coronary atherosclerotic plaque progression in East Asians and Caucasians by serial coronary computed tomographic angiography: A PARADIGM substudy

ObjectivesTo investigate potential differences in plaque progression (PP) between in East Asians and Caucasians as well as to determine clinical predictors of PP in East Asians.BackgroundStudies have demonstrated differences in cardiovascular risk factors as well as plaque burden and progression across different ethnic groups.MethodsThe study comprised 955 East Asians (age 60.4 ?± ?9.3 years, 50.9% males) and 279 Caucasians (age 60.4 ?± ?8.6 years, 74.5% males) who underwent two serial coronary computed tomography angiography (CCTA) studies over a period of at least 24 months. Patients were enrolled and analyzed from the PARADIGM (Progression of AtheRosclerotic PlAque DetermIned by Computed TomoGraphic Angiography IMaging) registry. After propensity-score matching, plaque composition and progression were compared between East Asian and Caucasian patients. Within East Asians, the plaque progression group (defined as plaque volume at follow-up CCTA minus plaque volume at baseline CCTA> 0) was compared to the no PP group to determine clinical predictors for PP in East Asians.ResultsIn the matched cohort, baseline volumes of total plaque as well as all plaque subtypes were comparable. There was a trend towards increased annualized plaque progression among East Asians compared to Caucasians (18.3 ?± ?24.7 ?mm³/year vs 16.6 ?mm³/year, p ?= ?0.054). Among East Asians, 736 (77%) had PP. East Asians with PP had more clinical risk factors and higher plaque burden at baseline (normalized total plaque volume of144.9 ?± ?233.3 ?mm³ vs 36.6 ?± ?84.2 ?mm³ for PP and no PP, respectively, p ?< ?0.001). Multivariate logistic regression analysis showed that baseline normalized plaque volume (OR: 1.10, CI: 1.10–1.30, p ?< ?0.001), age (OR: 1.02, CI: 1.00–1.04, p ?= ?0.023) and body mass index (OR: 2.24, CI: 1.01–1.13, p ?= ?0.024) were all predictors of PP in East Asians. Clinical events, driven mainly by percutaneous coronary intervention, were higher among the PP group with a total of 124 (16.8%) events compared to 22 (10.0%) in the no PP group (p ?= ?0.014).ConclusionEast Asians and Caucasians had comparable plaque composition and progression. Among East Asians, the PP group had a higher baseline plaque burden which was associated with greater PP and increased clinical events.     

CT-based total vessel plaque analyses improves prediction of hemodynamic significance lesions as assessed by fractional flow reserve in patients with stable angina pectoris

BackgroundCoronary stenosis and plaque evaluation by coronary computed tomography angiography (CTA) may contribute to identify hemodynamically relevant lesions. We evaluated the most stenotic lesion including plaques proximal to it versus a total vessel analyses combined with stenosis for ischemia.MethodsPatients scheduled for clinically indicated invasive coronary angiography (ICA) for suspected coronary artery disease underwent coronary CTA and ICA including fractional flow reserve (FFR) as part of the NXT trial (clinicaltrials.gov NCT01757678). Stenoses were visually graded ≤50%, 51–70%, and >70% on coronary CTA. Semi-automated plaque analyses were performed using a proximal to the FFR pressure sensor location (including the most severe lesion to the coronary ostium) versus a total vessel (vessel diameter ≥2 mm) approach. Coronary stenosis and plaque parameters were evaluated for discrimination of ischemia by logistic regressions and combined models analyzed using receiver operating characteristics (ROC) with invasive FFR≤ 0.80 as reference standard.ResultsIn 254 patients, mean (±SD) age 64 (±10) years, 64% male, a coronary CTA stenosis >50% was present in 239 (49%) vessels. Invasive FFR was ≤0.80 in 100 (21%) vessels. Coronary stenosis severity and low-density non-calcified plaque (LD-NCP) volume were independent predictors of ischemia in the “proximal” and “total-vessel” analyses. Stenosis severity + total vessel LD-NCP assessment performed better than stenosis severity + proximal LD-NCP evaluation (Area under curve [AUC] (95%CI): 0.83 (0.78–0.87) vs 0.81 (0.76–0.86), p-value = 0.009), whereas stenosis severity + proximal LD-NCP performed better than stenosis alone (AUC (95%CI): 0.81 (0.76–0.86) vs 0.78 (0.73–0.83), p-value = 0.019).ConclusionAdding total vessel high-risk plaque volume to stenosis severity improves discrimination of ischemia in coronary CTA performed in patients with stable angina pectoris.     

Reproducibility of quantitative plaque measurement in advanced coronary artery disease

BackgroundThe ability to characterize and to quantify the extent of coronary artery disease has the potential to improve the prognostic capability of coronary computed tomography angiography. Although reproducible techniques have been described in those with mild coronary disease, this has yet to be assessed in patients with advanced disease.MethodsTwenty patients with known multivessel disease underwent repeated computed tomography coronary angiography, 2 weeks apart. Coronary artery segments were analysed using semi-automated software by two trained observers to determine intraobserver, interobserver and interscan reproducibility.ResultsOverall, 149 coronary arterial segments were analysed. There was excellent intraobserver and interobserver agreement for all plaque volume measurements (Lin’s coefficient 0.95 to 1.0). There were no substantial interscan differences (P ?> ?0.05 for all) for total (2063 ?± ?1246 ?mm³, mean of differences ?35.6 ?mm³), non-calcified (1795 ?± ?910 ?mm³, mean of differences ?4.3 ?mm³), calcified (298 ?± ?425 ?mm³, mean of differences ?31.3 ?mm³) and low-attenuation (13 ?± ?13 ?mm³, mean of differences ?2.6 ?mm³) plaque volumes. Interscan agreement was highest for total and noncalcified plaque volumes. Calcified and low-attenuation plaque (?236.6 to 174 ?mm³ and -15.8 to 10.5 ?mm³ respectively) had relatively wider 95% limits of agreement reflecting the lower absolute plaque volumes.ConclusionIn the presence of advanced coronary disease, semi-automated plaque quantification provides excellent reproducibility, particularly for total and non-calcified plaque volumes. This approach has major potential to assess change in disease over time and optimize risk stratification in patients with established coronary artery disease.     

Predictive value of the coronary artery calcium score and advanced plaque characteristics: Post hoc analysis of the PREDICT registry

BackgroundWhether coronary plaque characteristics assessed in coronary computed tomography angiography (CCTA) in association with the coronary artery calcium score (CACS) have predictive value for coronary events is unclear. We aimed to examine the predictive value of the CACS and plaque characteristics for the occurrence of coronary events.MethodsAmong 2802 patients who were analyzed in the PREDICT registry, 2083 with suspected coronary artery disease (CAD) were studied using post hoc analysis. High-risk plaques were defined as having ≥2 adverse characteristics, such as low computed tomographic attenuation, positive remodeling, spotty calcification, and napkin-ring sign. An adjudicative composite of coronary events (cardiac death, nonfatal acute coronary syndrome, and coronary revascularization ≥3 months after indexed CCTA) were analyzed.ResultsSeventy-three (3.5%) patients had coronary events and 313 (15.0%) had high-risk plaques. Multivariate Cox proportional hazard analysis showed that high-risk plaques remained an independent predictor of coronary events (adjusted hazard ratio [HR] 1.95, 95% confidence interval [CI] 1.13–3.34, P ?= ?0.0154), as well as the log-transformed CACS (adjusted HR 1.24, 95% CI 1.11–1.39, P ?= ?0.0002) and the presence of obstructive stenosis (adjusted HR 5.63, 95% CI 3.22–10.12, P 0.0001). In subgroup analyses, high-risk plaques were independently predictive only in the low CACS class (<100).ConclusionThis study shows that assessment of adverse features by coronary plaque imaging independently predicts coronary events in patients with suspected CAD and a low CACS. Our findings suggest that the clinical value of high-risk plaques to CACS and stenosis assessment appears marginal.     

The effect of patient and imaging characteristics on coronary CT angiography assessed pericoronary adipose tissue attenuation and gradient

BackgroundCoronary CT angiography (CCTA) pericoronary adipose tissue (PCAT) markers are promising indicators of inflammation.ObjectiveTo determine the effect of patient and imaging parameters on the associations between non-calcified plaque (NCP) and PCAT attenuation and gradient.MethodsThis was a single-center, retrospective analysis of consecutive patients with stable chest pain who underwent CCTA and had zero calcium scores. CCTA images were evaluated for the presence of NCP, obstructive stenosis, segment stenosis and involvement score (SSS, SIS), and high-risk plaque (HRP). PCAT markers were assessed using semi-automated software. Uni- and multivariable regression models correcting for patient and imaging characteristics between plaque and PCAT markers were evaluated.ResultsOverall, 1652 patients had zero calcium score (mean age: 51 years ?± ?11 [SD], 871 women); PCAT attenuation values ranged between ?123 HU and ?51 HU, and 649 patients had plaque. In univariable analysis, the presence of NCP, SSS, SIS, and HRP were associated with PCAT attenuation (2, 1, 1, 6 HU; respectively; p ?< ?.001 all); while obstructive stenosis was not (1 HU, p ?= ?.58). In multivariable analysis, none of the plaque markers were associated with PCAT attenuation (0 HU p ?= ?.93, 0 HU p ?= ?.39, 1 HU p ?= ?.18, 2 HU p ?= ?.10, 1 HU p ?= ?.71, respectively), while patient and imaging characteristics showed significant associations, such as: male sex (1 HU, p ?= ?.003), heart rate [1/min] (?0.2 HU, p ?< ?.001), 120 ?kVp (8 HU, p ?< ?.001) and pixel spacing [mm³] (32 HU, p ?< ?.001). Similar results were observed for PCAT gradient.ConclusionPCAT markers were significantly associated with NCP, however the associations did not persist following correction for patient and imaging characteristics.     

Correlation of concentrations of high-sensitivity troponin T and high-sensitivity C-reactive protein with plaque progression as measured by CT coronary angiography

BackgroundElevated levels of inflammatory biomarkers are associated with increased cardiovascular morbidity and mortality.ObjectiveWe sought to determine whether elevated concentrations of high-sensitivity troponin T (hs-TnT) and high-sensitivity C-reactive protein (hs-CRP) predict progression of coronary artery disease (CAD) as determined by coronary CT angiography (coronary CTA).MethodsPatients presenting to the emergency department with acute chest pain who initially showed no evidence of an acute coronary syndrome underwent baseline and follow-up coronary CTA (median follow-up, 23.9 months) using identical acquisition and reconstruction parameters. Coronary CTA data of each major coronary artery were co-registered. Cross-sections were assessed for the presence of calcified and noncalcified plaques. Progression of atherosclerotic plaque and change of plaque composition from noncalcified to calcified plaque was evaluated and correlated to levels of hs-TnT and hs-CRP at the time of the baseline CT.ResultsFifty-four patients (mean age, 54.1 years; 59% male) were included, and 6775 cross-sections were compared. CAD was detected in 12.2 ± 21.2 cross-sections per patient at baseline. Prevalence of calcified plaque increased by 1.5 ± 2.4 slices per patient (P < .0001) over the follow-up period. On average, 1.6 ± 3.6 slices with new noncalcified plaque were found per patient (P < .0001) and 0.7 ± 1.7 slices with pre-existing noncalcified plaque had progressed to calcified plaque (P < .0001). After multivariate adjustment, change of overall CAD burden was predicted by baseline hs-TnT and hs-CRP (r = 0.29; P = .039 and r = 0.40; P = .004). Change of plaque composition was associated with baseline hs-TnT (r = 0.29; P = .03).ConclusionConcentrations of hs-TnT and hs-CRP are weakly associated with a significant increase in CAD burden and change in plaque composition over 24 months independent of baseline risk factors.     

Impact of age on coronary artery plaque progression and clinical outcome: A PARADIGM substudy

BackgroundThe association of age with coronary plaque dynamics is not well characterized by coronary computed tomography angiography (CCTA).MethodsFrom a multinational registry of patients who underwent serial CCTA, 1153 subjects (61 ± 5 years old, 61.1% male) were analyzed. Annualized volume changes of total, fibrous, fibrofatty, necrotic core, and dense calcification plaque components of the whole heart were compared by age quartile groups. Clinical events, a composite of all-cause death, acute coronary syndrome, and any revascularization after 30 days of the initial CCTA, were also analyzed. Random forest analysis was used to define the relative importance of age on plaque progression.ResultsWith a 3.3-years’ median interval between the two CCTA, the median annual volume changes of total plaque in each age quartile group was 7.8, 10.5, 10.8, and 12.1 mm³/year and for dense calcification, 2.5, 4.6, 5.4, and 7.1 mm³/year, both of which demonstrated a tendency to increase by age (p-for-trend = 0.001 and < 0.001, respectively). However, this tendency was not observed in any other plaque components. The annual volume changes of total plaque and dense calcification were also significantly different in the propensity score-matched lowest age quartile group versus the other age groups as was the composite clinical event (log-rank p = 0.003). In random forest analysis, age had comparable importance in the total plaque volume progression as other traditional factors.ConclusionsThe rate of whole-heart plaque progression and dense calcification increases depending on age. Age is a significant factor in plaque growth, the importance of which is comparable to other traditional risk factors.Clinical trial registrationURL: http://www.clinicaltrials.gov. Unique identifiers: NCT02803411.     

Sex differences in computed tomography angiography-derived coronary plaque burden in relation to invasive fractional flow reserve

BackgroundDistinct sex-related differences exist in coronary artery plaque burden and distribution. We aimed to explore sex differences in quantitative plaque burden by coronary CT angiography (CCTA) in relation to ischemia by invasive fractional flow reserve (FFR).MethodsThis post-hoc analysis of the PACIFIC trial included 581 vessels in 203 patients (mean age 58.1 ​± ​8.7 years, 63.5% male) who underwent CCTA and per-vessel invasive FFR. Quantitative assessment of total, calcified, non-calcified, and low-density non-calcified plaque burden were performed using semiautomated software. Significant ischemia was defined as invasive FFR ≤0.8.ResultsThe per-vessel frequency of ischemia was higher in men than women (33.5% vs. 7.5%, p ​< ​0.001). Women had a smaller burden of all plaque subtypes (all p ​< ​0.01). There was no sex difference on total, calcified, or non-calcified plaque burdens in vessels with ischemia; only low-density non-calcified plaque burden was significantly lower in women (beta: -0.183, p ​= ​0.035). The burdens of all plaque subtypes were independently associated with ischemia in both men and women (For total plaque burden (5% increase): Men, OR: 1.15, 95%CI: 1.06–1.24, p ​= ​0.001; Women, OR: 1.96, 95%CI: 1.11–3.46, p ​= ​0.02). No significant interaction existed between sex and total plaque burden for predicting ischemia (interaction p ​= ​0.108). The addition of quantitative plaque burdens to stenosis severity and adverse plaque characteristics improved the discrimination of ischemia in both men and women.ConclusionsIn symptomatic patients with suspected CAD, women have a lower CCTA-derived burden of all plaque subtypes compared to men. Quantitative plaque burden provides independent and incremental predictive value for ischemia, irrespective of sex.     

Increased coronary pericoronary adipose tissue attenuation in diabetic patients compared to non-diabetic controls: A propensity score matching analysis

BackgroundPericoronary adipose tissue (PCAT) attenuation is an indicator of active inflammation of perivascular adipose tissue, which is supposed to increase in diabetic patients. We aimed to investigate the PCAT attenuation values and high-risk plaque (HRP) features in diabetic and non-diabetic subjects with different stenotic extents.MethodsConsecutive type 2 diabetes patients and non-diabetic patients with chest pain and intermediate pre-test probability of coronary artery disease (CAD) were prospectively enrolled and underwent coronary computed tomography angiography (CCTA). At per-patient level, PCAT attenuation values of three major epicardial coronary vessels, as well as HRP features were measured. PCAT attenuation values and HRP features were compared between diabetic and non-diabetic subjects according to the presence or absence of obstructive stenosis.Results1700 patients (mean age: 65.5 ?± ?11.7, 940 males) were divided into two groups according to presence of obstructive stenosis on CCTA. Propensity score matching was performed in further analysis. RCA_PCAT was significantly higher in diabetic subjects than that in non-diabetic subjects, regardless of the presence of obstructive stenosis (?83.60 ?± ?9.51 HU vs. ?88.58 ?± ?9.37 HU, p ?< ?0.001) or absence of obstructive stenosis (?83.70 ?± ?10.32 HU vs. ?88.76 ?± ?8.28 HU, p ?< ?0.001). In contrast, HRP features were more commonly presented in diabetic patients with obstructive stenosis than in those without obstructive stenosis. According to subgroup analysis based on acquisition tube voltage, RCA_PCAT was the only parameter showing consistent difference between diabetic and non-diabetic patients.ConclusionsRCA_PCAT was significantly higher in diabetic patients than that in non-diabetic patients regardless of stenotic severity and plaque vulnerability.     

Longitudinal assessment of coronary plaque volume change related to glycemic status using serial coronary computed tomography angiography: A PARADIGM (Progression of AtheRosclerotic PlAque DetermIned by Computed TomoGraphic Angiography Imaging) substudy

BackgroundData on the impact of glycemic status on coronary plaque progression have been limited. This study evaluated the association between glycemic status and coronary plaque volume change (PVC) using coronary computed tomography angiography (CCTA).MethodsA total of 1296 subjects (61 ± 9, 56.9% male) who underwent serial CCTA with available glycemic status were enrolled and analyzed from the Progression of AtheRosclerotic PlAque DetermIned by Computed TomoGraphic Angiography IMaging (PARADIGM) registry. The median inter-scan period was 3.2 (2.6–4.4) years. Quantitative assessment of coronary plaques was performed at both scans. All participants were categorized into the following groups according to glycemic status: normal, pre-diabetes (pre-DM), and diabetes mellitus (DM).ResultsDuring the follow-up, significant differences in PVC (normal: 51.3 ± 83.3 mm³ vs. pre-DM: 51.0 ± 84.3 mm³ vs. DM: 72.6 ± 95.0 mm³; p < 0.001) and annualized PVC (normal: 14.9 ± 24.9 mm³ vs. pre-DM: 15.7 ± 23.8 mm³ vs. DM: 21.0 ± 27.7 mm³; p = 0.001) were observed among the 3 groups. Compared with normal individuals, individuals with pre-DM showed no significant differences in the adjusted odds ratio (OR) for plaque progression (PP) (1.338, 95% confidence interval [CI] 0.967–1.853; p = 0.079). However, the adjusted OR for PP was higher in DM individuals than in normal individuals (1.635, 95% CI 1.126–2.375; p = 0.010).ConclusionDM had an incremental impact on coronary PP, but pre-DM appeared to have no significant association with an increased risk of coronary PP after adjusting for confounding factors.Clinical trial registrationClinicalTrials.gov NCT02803411.     

Noncalcified atherosclerotic lesions with vulnerable characteristics detected by coronary CT angiography and future coronary events

BackgroundThe ability of coronary CT angiography (CTA) findings such as plaque characteristics to predict future coronary events remains controversial.ObjectiveWe investigated whether noncalcified atherosclerotic lesions (NCALs) detected by coronary CTA were predictive of future coronary events.MethodsA total of 511 patients who underwent coronary CTA were followed for cardiovascular events over a period of 3.3 ± 1.2 years. The primary end point was defined as hard events, including cardiac death, nonfatal myocardial infarction, or unstable angina that required urgent hospitalization. Early elective coronary revascularizations (n = 58) were excluded. The relationship between features of NCALs and outcomes is described.ResultsA total of 15 hard events (2 cardiac deaths, 7 myocardial infarctions, 6 cases of unstable angina that required urgent hospitalization) were documented in the remaining 453 patients with modest risks during a follow-up period of 3.3 ± 1.2 years. For these hard events, a univariate Cox proportional hazard model showed that the hazard ratio for the presence of >50% stenosis was 7.27 (95% CI, 2.62–21.7; P = .0002). Although the presence of NCAL by itself was not statistically significant, NCALs with low attenuation and positive remodeling (low-attenuation plaque [LAP] and positive remodeling [PR]; plaque CT number ≤34 HU and remodeling index ≥1.20) showed an adjusted hazard ratio of 11.2 (95% CI, 3.71–36.7; P < .0001). With C-statistics analysis, when both LAP and PR and >50% stenosis were added, the C-statistic was significantly improved compared with the basal model adjusted for age, sex, and log₂ (Agatston score +1) (0.900 vs 0.704; P = .0018).ConclusionsIdentification of NCALs with LAP and PR characteristics by coronary CTA provides additional prognostic information to coronary stenosis for the prediction of future coronary events.     

Impact of Non-obstructive left main disease on the progression of coronary artery disease: A PARADIGM substudy

BackgroundThe aim of the study is examine the impact of non-obstructive (<50%stenosis) left main (LM) disease on the natural history of coronary artery disease using serial coronary computed tomography angiography (CTA).MethodsCTAs from the PARADIGM (Progression of atherosclerotic plaque determined by computed tomographic angiography imaging) study, a prospective multinational registry of patients who underwent serial CTA at a ≥2 year interval were analyzed. Those without evidence of CAD on their baseline scan were excluded, as were those with obstructive left main disease. Coronary artery vessels and their branches underwent quantification of: plaque volume and composition; diameter stenosis; presence of high-risk plaque.ResultsOf 944 (62 ± 9 years, 60% male) who had evidence of CAD at baseline, 444 (47%) had LM disease. Those with LM disease had a higher baseline plaque volume (194.8 ± 221mm3 versus 72.9 ± 84.3mm3, p < 0.001) and a higher prevalence of high-risk plaque (17.5% versus 13%, p < 0.001) than those without LM disease. On multivariable general linear model, patients with LM disease had greater annual rates of progression of total (26.5 ± 31.4mm3/yr versus 14.9 ± 20.1mm3/yr, p < 0.001) and calcified plaque volume (17 ± 24mm3/yr versus 7 ± 11mm3/yr, p < 0.001), with no difference in fibrous, fibrofatty or necrotic core plaque components.ConclusionThe presence of non-obstructive LM disease is associated with greater rates of plaque progression and a higher prevalence of high-risk plaque throughout the entire coronary artery tree compared to CAD without LM involvement. Our data suggests that non-obstructive LM disease may be a marker for an aggressive phenotype of CAD that may benefit from more intensive treatment strategies.     

Quantification and characterisation of coronary artery plaque volume and adverse plaque features by coronary computed tomographic angiography: a direct comparison to intravascular ultrasound

Objective

We evaluated the performance of manual measures of coronary plaque volumes and atherosclerotic plaque features from coronary CT angiography (CTA), using intravascular ultrasound (IVUS) as the reference.

Methods

Thirty individual coronary plaques with suitable fiduciary markers were identified. Plaque volumes on coronary CTA were manually quantified by two observers and compared to IVUS plaque volumes as interpreted by an independent laboratory. The presence of adverse plaque characteristics—low attenuation plaque (LAP), positive remodelling (PR) and spotty calcification (SC)—on coronary CTA was evaluated and compared to IVUS.

Results

High correlation in plaque volumes was detected between observers (r?=?0.94, P?<?0.0001; 95 % limits of agreement <48.7 mm³, bias 6.6 mm³). Excellent correlation (r?=?0.95, P?<?0.0001) was noted in plaque volume between independent observers and IVUS (95 % limits of agreement <40.6 mm³, bias ?4.4 mm³) and did not differ from IVUS (105.0?±?56.7 vs. 109.4?±?60.7 mm³, P?=?0.2). The frequency of LAP (10 % vs. 17 %), PR (7 % vs. 10 %) and SC (27 % vs. 33 %) was similar between coronary CTA and IVUS (all P?=?NS).

Conclusions

Plaque volume on coronary CTA determined by manual methods demonstrates high correlation and modest agreement to IVUS. Further, coronary CTA demonstrates high accuracy for the identification of adverse plaque characteristics, including LAP, PR and SC.

Key Points

? Coronary CT angiography is a non-invasive test that enables coronary plaque assessment ? Plaque quantification by coronary CT angiography correlates well with intravascular ultrasound findings ? Coronary CT angiography can identify adverse plaque characteristics