Coronary Artery Plaque Research Articles

Abstract 4145859: Clonal Hematopoiesis of Indeterminate Potential Increases Mortality Risk in Coronary Artery Disease

Background: Clonal hematopoiesis of indeterminate potential (CHIP) has been associated with an increased incidence of common late-onset diseases including myocardial infarction. Research Question: Here we examined the impact of CHIP on mortality in patients with coronary artery disease (CAD) and further explored potential underlying mechanisms. Methods: CAD patients were examined for CHIP-defining mutations using deep DNA sequencing. Propensity score matching was used to compare CHIP CAD with non-CHIP CAD patients. Survival was analyzed using Kaplan-Meier curves and Cox proportional hazard models. Functional aspects were investigated at the protein and RNA level in cardiovascular relevant human postmortem tissue from the Munich cardIovaScular StudIes biObaNk (MISSION), in CAD patients from an independent cohort and in in-vitro macrophage models. Results: Within 7,933 CAD patients screened by deep-DNA-sequencing with a 13 gene panel, 2,002 carried at least one CHIP defining mutation with a variant allele frequency ≥2%. After 1:1 matching with non-CHIP carriers we revealed a significantly elevated 3-year mortality in the group of CHIP carriers [HR 1.48 (CI 95% 1.23-1.78); p<0.0001)] as well as in carriers of mutations in one out of seven individual genes – ASXL1 , DNMT3A , PPM1D , SF3B1 , SRSF2 , TET2 , and U2AF1 . In human coronary atherosclerotic plaque we visualized CHIP-mutations within leukocytes. Further, within coronary artery plaque of deceased TET2 mutation carriers (n=26 vs. n=13 controls) we identified by proteomic profiling an upregulation of inflammatory and metabolic pathways, including enhanced lipid metabolism. In an independent cohort of CAD patients undergoing coronary bypass surgery, RNA sequencing data from monocyte-derived macrophages revealed in TET2 CHIP carriers associations with CAD complexity. TET2 -mutated macrophages studied in-vitro revealed an increased uptake of low-density lipoprotein (LDL) and oxidized LDL-cholesterol besides a known upregulation of inflammatory pathways. Conclusion: In summary, this study emphasizes CHIP as a significant prognostic factor in CAD patients, associated with increased complexity of CAD and altered gene expression within human coronary artery plaques. Mechanistically, TET2 mutations modify the behavior of CHIP-affected macrophages, leading to heightened inflammation and increased uptake of LDL-cholesterol.

Abstract 4136274: A Case of Myocardial Infarction with Non-obstructive Coronary Arteries (MINOCA) Complicated by a Ventricular Septal Defect (VSD)

Case: A 69-year-old woman with a history of hypertension and tobacco use disorder presented with acute chest pain. The patient was found to have classic anterior ST elevation myocardial infarction (STEMI) pattern on electrocardiogram (ECG) with high-sensitivity troponin of 12,772 ng/L and was taken emergently to the catheterization laboratory. Coronary angiography showed tortuous coronary vessels though without evidence of obstructive coronary artery disease, plaque rupture, ulceration, dissection, or vasospasm. Transthoracic echocardiogram showed an apical ventricular septal defect (VSD) with normal left ventricular systolic function of 60%. Cardiac computed tomography (CT), confirmed a discrete apical VSD that was 7.93 mm in diameter and multiple small VSDs distally in the septum. Right heart catheterization revealed severe left-to-right shunting with a ratio of pulmonary blood flow to systemic blood flow (Qp:Qs) of 2.8. Early surgical repair of the apical VSD was pursued despite known high operative risk given the hemodynamic significance of the shunt. The patient developed ongoing hemodynamic instability from cardiogenic shock with inability to ween from intra-aortic balloon pump (IABP). Unfortunately, because of the location of the residual VSDs and elevated panel-reactive antibody testing of 98%, the patient was deemed to not be a candidate for percutaneous closure or heart transplantation, respectively. Discussion: An acquired ventricular septal defect (VSD) is a rare and catastrophic complication of myocardial infarction, typically with a culprit obstructive coronary artery lesion identified on coronary angiography. Acquired VSDs in myocardial infarction with nonobstructive coronary arteries (MINOCA) is an even more rare phenomenon. Possible causes include low flow, inflammation, intimal disruption, or vasospasm of coronary arteries. Our case highlights that MINOCA can present with life-threatening complications similar to obstructive STEMI. The timing of intervention and treatment approach of acquired VSDs remains an area of debate. The life-threatening effects of VSDs make it critical to manage in a multidisciplinary manner involving advanced imagers, interventional cardiologists, cardiothoracic surgeons, and heart failure specialists. This case emphasizes the importance of maintaining a high index of suspicion for abnormal coronary anatomy, even in patients with MINOCA, and prompt interdisciplinary decision making to reduce mortality.

Prevalence of high-risk plaque features on cardiac computed tomography scans in patients with a coronary artery calcium score of zero

Abstract Introduction Coronary artery calcium (CAC) score of zero (so-called "power of zero") is associated with a very low rate of major adverse cardiac events (MACE), especially during short and midterm follow-up. However, a CAC score of zero does not definitively exclude the presence of atherosclerotic plaques or obstructive coronary artery disease (CAD). The composition of atherosclerotic plaques and the frequency of high-risk plaque features in this population are not well described. Purpose We sought to characterize the composition of atherosclerotic plaques and assess the frequency of high-risk plaque features on contrast-enhanced computed tomography (CT) images in patients with a zero CAC score. Methods The study enrolled patients with stable chest pain suspected of CAD referred for coronary CT imaging and having a CAC score of zero. Coronary CT angiography images were assessed by an expert reader to identify atherosclerotic plaques and high-risk plaque features in all coronary arteries with a diameter ≥1.5mm. The coronary artery lumen and plaques were manually segmented, and the degree of stenosis was evaluated following the Coronary Artery Disease Reporting and Data System (CAD-RADS) criteria. The presence of four high-risk plaque features was identified: positive remodeling, spotty calcification, low-attenuation plaque, and napkin ring sign. Total plaque volume, percent atheroma volume, and plaque composition were quantified using dedicated software (Figure 1). Results A total of 145 patients (mean age 54.2±12.1 years, 35.9% males) were included in the analysis. At least one coronary artery plaque was identified in 30 individuals (20.7%). 22 (15.2%), 7 (4.8%), and 1 (0.7%) patients were categorized into CAD-RADS 1, CAD-RADS 2, and CAD-RADS 3 categories, respectively. Among 30 patients with any coronary artery plaque, at least one high-risk feature was found in 10 individuals (33.3%), while 3 individuals (10.0%) had two features. Positive remodeling was found in 7 (23.3%), spotty calcification in 3 (10.0%), low-attenuation plaque in 3 (10.0%), and napkin ring sign in 0 patients, respectively (Figure 1). The mean total plaque volume was 48.2±54.3mm³, and the mean percent atheroma volume was 1.2±0.8%. Total plaque volume comprised low-attenuation (0.4%), fibro-fatty (58.9%), fibrous (39.4%), and calcified (1.3%) plaque volumes. Notably, in 3 (10.0%) individuals, the presence of calcified plaque was identified, which on non-contrast CT images did not meet the Agatston criteria for the CAC score. Conclusions Our study demonstrates a significant prevalence of atherosclerotic plaques and high-risk plaque features in patients with a CAC score of zero. Specifically, one in every five study participants had identifiable atherosclerotic plaque, with one in every three of those exhibiting one or more high-risk plaque features. The prognostic significance of these findings warrants further evaluation in studies with longitudinal follow-up.

Impact of ultra-high-resolution on cardiac CT assessment of coronary artery stenoses, plaque burden/composition, and pericoronary adipose tissue attenuation

Abstract Background Conventional coronary computed tomography angiography (CCTA) overestimates stenoses within stents and calcified arteries due to "blooming" artifacts. Ultra-high-resolution coronary CT (UHR-CT) may overcome this limitation because of higher spatial resolution. Purpose To investigate differences in coronary arterial lumen volume, stenosis severity, and plaque composition, between CCTA and UHRCT in patients with stents and/or high coronary calcium scores. Methods As part of a prospective pilot study, 14 patients referred for invasive coronary angiography for evaluation of obstructive CAD underwent UHRCT (Canon Precision, 160 x 0.25mm slices) prior to catheterization. Images of identical cardiac phases were reconstructed in two badges for comparison: 1) Ultra-high resolution using a 1,024 x 1,024 matrix, 0.25 mm, and 2) conventional resolution with a 524 x 524 matrix, 0.5 mm. All images were reconstructed using iterative reconstruction algorithm (AIDR 3D) and a sharp kernel (FC05). For the left main and three coronary arteries, an automated contour analysis using a dedicated software (QAngioCT RE 3.2, Medis, Netherlands) was performed to compare conventional CCTA vs. UHR-CT resolution images across common vascular and plaque metrics, including lumen and vessel volume, plaque burden/volume, plaque composition based upon predefined fixed intensity cut-off values of CT attenuation, minimal and maximal plaque thickness, pericoronary adipose tissue attenuation (PCAT), minimal lumen area and diameter, and diameter stenosis. All lumen and vessel contours were generated by the software, without manual editing. The segment model proposed by the SCCT was used as reference and the lesions classified as greater than 25% stenosis by visual assessment were recorded. The quality of the images was subjectively assessed using a 5-point Likert scale. Vessel segments with scores 1 (severe artifacts) and 2 (pronounced artifacts) were not included in the analysis. Results The mean patient age was 68.5 years (±6.8), 2 were female (14.3%), 6 patients had stents (11 stented segments) and the mean Agatston score was 947.6 (±449) among the 8 non-stented patients. A total of 56 vessels, 133 segments, and 57 lesions were analyzed. Eight segments (6%) were excluded from the analysis due to poor quality. Results on a per segment and per lesion basis were summarized in the table. The mean PCAT value was significantly lower for the UHRCT images compared to NR reconstruction in both segment (p<0.001) and lesion based (p=0.002) analyses. Plaque differentiation varied by UHRCT resulted in a lower fibrous plaque volumes but higher necrotic (low attenuation) plaque volumes. Conclusions Ultra-high-resolution CT image analysis results in significantly different coronary artery plaque volume and PCAT assessment vs. conventional resolution CCTA. These findings have implications for evaluating high-risk plaque features and perivascular inflammation in patients.Table 1

Relationship between coronary artery calcium score and plaque vulnerability in patients with established coronary artery disease

Abstract Introduction Coronary artery calcium (CAC) score is widely used for risk stratification. However, in patients with established coronary artery disease (CAD), its clinical implication and relationship with plaque vulnerability have not been fully investigated. Purpose We sought to investigate the relationship between CAC score and plaque vulnerability assessed by optical coherence tomography (OCT). Methods Patients with CAD who had both CAC score and OCT prior to percutaneous coronary intervention were included. The patients with a prior history of coronary revascularization were excluded. Patients were divided into five groups based on CAC score; CAC score of 0, 1-99, 100-399, 400-999, and over 1000. Vulnerable features in culprit plaque assessed by OCT were compared among these five groups. Results In 460 patients, the prevalence of lipid-rich plaque, macrophage, and cholesterol crystal significantly differed among the five groups: lowest in the patients with a CAC score of zero. The prevalence of thin-cap fibroatheroma (TCFA) tended to be lower in those with a CAC score of zero (Figure). In the two-group comparison between the group with a CAC score of zero and the other four groups, the prevalence of lipid-rich plaque (60.5 vs. 85.9%, p < 0.001), macrophage (48.8 vs. 74.1%, p < 0.001), TCFA (16.3 vs. 35.0%, p = 0.013), and cholesterol crystal (11.6 vs. 32.9%, p = 0.004) was significantly lower in the patients with CAC score of zero. No significant difference in vulnerable features was observed among the four groups with CAC scores > 0. CAC score of zero was independently negatively associated with the lipid-rich plaque (odds ratio [OR] 0.246, p < 0.001), macrophage (OR 0.348, p = 0.003), TCFA (OR 0.285, p = 0.006), and cholesterol crystal (OR 0.273, p = 0.010) after adjustment with patient characteristics. Conclusion This is the first study that investigated the relationship between CAC score and plaque vulnerability assessed by OCT in patients with known CAD. Patients with CAC score of zero have a significantly lower prevalence of vulnerable plaque features compared to those with CAC score > 0.

Age stratified differences in coronary artery plaque phenotype in women and men with non-obstructive coronary artery disease

Abstract Background Development of coronary artery disease (CAD) and risk of acute cardiac events differ between women and men during the life span. The aim of this study was therefore to characterize sex differences in coronary artery plaque phenotype among patients with symptomatic non-obstructive CAD in different age groups. Methods Advanced coronary artery plaque phenotyping by coronary computed tomography angiography was performed in 606 patients (31% women) with symptomatic non-obstructive CAD from the Norwegian Registry of Invasive Cardiology. A 1:1 sex-matched study design ensured equal distribution of the sexes in the different age groups. We assessed total plaque burden adjusted for vessel volume and plaque composition consisting of dense calcium, fibrous, fibro-fatty, and necrotic core. Patients were further stratified into age groups of ≤50, 51-64, and ≥65 years to explore the relationship between age and sex on coronary artery plaque phenotype. Results In the study population, patients ≥65 years had a higher prevalence of hypertension, higher calcium score, coronary artery segment involvement score and total plaque burden, whereas the prevalence of obesity was lower compared to patients aged 51-64 and ≤50 years (all p<0.05). The prevalence of smoking, diabetes and statin treatment was similar between groups. A two-way analysis of variance demonstrated an interaction between sex and age group on total plaque burden (F [2, 600] =3.431, p=0.33), where women aged 51-64 and ≥65 years had a higher total plaque burden compared to men (p=0.002 and p<0.001, respectively, Figure 1). Plaque composition in women ≥65 years was characterized by an increased proportion of stable dense calcified plaques compared to men and younger women (all p<0.05), whereas men ≥65 years had a higher proportion of vulnerable necrotic core plaque phenotype (p<0.001). Women showed consistently lower proportions of more vulnerable fibro-fatty plaques compared to men across all age groups (all p<0.05, Figure 2). Conclusions In non-obstructive CAD, higher total plaque burden was associated with older age and female sex. Women had a lower proportion of vulnerable fibro-fatty plaques across all age groups and a higher proportion of stable dense calcified plaques at an older age compared to men. Future longitudinal studies on coronary artery plaque phenotype during the life span will increase the understanding of sex differences in CAD development and may contribute to customise risk stratification in women and men.Figure 1.Total plaque burdenFigure 2.Compositional plaque burden

Early coronary artery atherosclerosis in humans is associated with attenuated coronary retention of klotho

Abstract Background Vascular aging is a key feature of cardiovascular disease. α-klotho (klotho) is a protein inversely associated with aging and may contribute to vascular repair. Lower levels of systemic klotho have been identified in humans with features of early and advanced coronary atherosclerosis. It remains unknown if circulating klotho is present within human coronary circulation and whether cardiovascular klotho retention correlates with atherosclerosis. Purpose The current study aimed to assess the presence of klotho within coronary circulation compared to systemic circulation and hypothesized that net coronary klotho retention is attenuated in patients with early age-related features of coronary artery disease (CAD). Methods A total of 42 patients that underwent clinically indicated coronary angiogram for chest pain that had no obstructive CAD underwent intravascular ultrasound (IVUS) assessment were retrospectively examined. Virtual histology assessed coronary plaque characteristics. Blood samples simultaneously collected from the proximal aorta and coronary sinus were used for klotho detection using enzyme-linked immunosorbent assay. The net gradient of klotho across cardiovascular circulation was calculated by multiplying the arteriovenous klotho gradient by basal coronary blood flow. A net positive gradient indicated less cardiovascular klotho retention; a net negative gradient indicated greater cardiovascular klotho retention. Results Overall, participants were age 54±10 years old and 76% were female. There were overall higher levels of klotho within the coronary sinus (median 0.49 ng/mL [0.15; 1.69]) compared to systemic circulation (median 0.30 ng/mL [0.16; 1.14]). Participant groups were determined by those with positive (n = 20) or negative (n = 22) cardiovascular retention of klotho. Both groups were similar in age (56 ±2 vs. 51 ±2 years old, p = 0.080), gender (72% vs. 80% female, p = 0.580), and had similar occurrences of traditional cardiovascular comorbidities. Those with less cardiovascular klotho retention in the coronary vascular bed had significantly greater degree of non-obstructive coronary artery plaque (Gensini score 3.5 vs. 0, p < 0.001) and had higher percent plaque burden (46% [35; 53] vs. 34% [28; 46], p = 0.044) than those with greater cardiovascular klotho retention. Conclusions Patients with early coronary atherosclerosis may be characterized by attenuated retention of klotho within coronary circulation. Moreover, humans appear to have higher circulating klotho in coronary circulation than in systemic circulation. The current study may support a role for mechanism or potential therapeutic target for klotho in coronary atherosclerosis in humans.

Combined mammographic breast density and breast arterial calcification is incrementally predictive of coronary artery disease beyond traditional risk factors

Abstract Background Coronary artery disease (CAD) risk is underestimated in women using current risk stratification tools. The mammographic finding of breast arterial calcification (BAC) associates with CAD. Furthermore, breast adipose tissue, measured through breast density (BD) on mammography (low breast density indicates high adiposity) has shown potential to act as a pro-inflammatory, pro-atherogenic fat deposit. Given its uptake in screening programs, mammography may therefore represent a novel risk stratification tool for cardiovascular disease in women. Purpose To evaluate the association between the combined mammographic features of BD and BAC, with CAD. Methods Single-centre, retrospective, cross-sectional study, including 153 women, mean age 62±10, who had both clinically indicated mammography, and coronary computed tomography angiogram (CCTA) for suspected CAD. CAD risk was identified by the CAD Consortium Score, with a 15% threshold for low and high risk. BD was visually assessed and categorised by 4-level BI-RADS grade with grade A-B representing low density, and C-D representing high density (Figure 1). BAC was visually assessed and categorised as present/absent (Figure 1). CAD was categorised as presence/absence of coronary artery plaque on CCTA. Logistic regression was performed with results presented as Odds Ratio (OR) and [95% Confidence Intervals]. Receiver operator characteristic area under the curve (AUC) was used for model discrimination. Results Low BD (n=103 (67%)) was associated with CAD (OR 3.20 [1.58-6.53], p=0.001, as was BAC presence (n=37 (24%), OR 4.36 [1.58-12], p=0.004). There were 51 (33%) with elevated CAD risk. Participants were categorised into 4 subgroups based on low/high BD and presence/absence of BAC: 29 (19%) had low BD and BAC, 74 (48%) had low BD and no BAC, 8 (5%) had high BD and BAC and 42 (27%) had high BD and no BAC. Significantly higher proportions of CAD were noted with low BD and BAC alone, as well as combined low BD and BAC (Figure 2). Compared with high BD/BAC negative, the presence of low BD and BAC independently associated with CAD (OR 5.27 [1.19-23.3], p=0.03). Significant incremental benefit was seen after adding BD/BAC status to CAD Consortium Score (AUC 0.65 vs. 0.72, p=0.004). Conclusions Combined, and individual mammographic features of low BD and BAC presence are associated with CAD and improve risk prediction beyond standard coronary risk probabilities. Standardised reporting of these features to inform risk identification may be of further benefit and should be tested in prospective screening studies.

Association between lipoprotein particle concentration and size and progression of coronary plaque: the MACS Longitudinal Coronary CT angiography study

Abstract Background People living with HIV have greater risk of cardiovascular diseases (CVD) than people without HIV and tend to have different risk profiles, including higher serum triglycerides and lower LDL cholesterol levels. Nuclear magnetic resonance (NMR) provides a detailed phenotype of lipoproteins. Purpose To examine the associations between lipoprotein particle concentrations and size and progression of coronary artery plaque among people living with and without HIV, and whether these associations differ by HIV serostatus. Methods Men with no clinical CVD in the Multicenter AIDS Cohort Study (MACS) who underwent a coronary CT angiography at baseline (2010-13) and follow-up (2015-17) were included. NMR spectroscopy was completed on fasting serum samples at baseline. Logistic regression models for the change in total coronary plaque volume (in tertiles) were estimated with NMR-derived lipoproteins as predictors. Levels were log-transformed and standardized to make results comparable. Models were adjusted for demographics, statin use and HIV serostatus (model 1) with addition of CVD risk factors (model 2). Interactions by HIV serostatus were also tested. Results A total of 549 men (314 with HIV; 235 without HIV) were included. Mean age was 53 ±7 years; 58% were White, 30% Black, and 12% Hispanic. Coronary plaque was present in 70% and plaque volume progressed in 79% of the cohort. Among men with HIV, 81% had undetectable HIV RNA and 12% had a diagnosis of AIDS at baseline. Men with HIV had significantly higher levels of small LDL-P, and total, medium and large VLDL-P levels compared to men without HIV, and lower levels of total, small and large HDL-P (Table 1). Men with HIV had significantly greater progression of plaque volume (37 mm3) compared to men without HIV (31 mm3, p<0.05). Levels of total and small LDL-P concentrations were directly associated with plaque progression, whereas large HDL-P was inversely associated with plaque progression in the combined sample (Model 2). Associations between total and small LDL-P with plaque progression were stronger in men with HIV than in men without HIV in models 1 and 2 (interaction p<0.01). While associations in fully adjusted models for total VLDL-P and small VLDL-P were significant in men without HIV, there were no significant associations between these particle concentrations with coronary plaque progression among men without HIV (interaction p< 0.01) (Model 2, Table 2). Conclusion Associations between lipid particle concentrations and coronary plaque progression differed between men with and without HIV, with stronger associations seen in men without HIV for total and small LDL-P. Despite having higher VLDL and lower HDL particle concentrations at baseline, these particle concentrations were only associated with plaque progression in men without HIV. Further research is needed to elucidate HIV specific factors for plaque progression to tailor risk reduction strategies.

Serial optical coherence tomography assessment of coronary atherosclerosis and long-term clinical outcomes

Abstract Background The impact of high-risk coronary artery plaques identified using optical coherence tomography (OCT) on late luminal narrowing and clinical events remains poorly understood. Methods This multicenter prospective study included 176 patients who underwent percutaneous coronary intervention (PCI) and serial OCT at baseline and 1-year follow-up to investigate non-target regions with angiographically intermediate stenosis. The primary outcome measure was luminal narrowing within the matched regions of interest in the non-target regions over a 1-year period. The secondary outcome measures included all-cause death, cardiac death, nonfatal myocardial infarction, and ischemia-driven coronary artery revascularization within 3 years. Results At 1 year after PCI, the coronary artery lumen area in non-target regions significantly decreased from 6.06 (95% confidence interval [CI], 5.60–6.53) to 5.88 (95% CI, 5.41–6.35) mm2, with a difference of -0.18 (95% CI, -0.22 to -0.14 mm2; P<0.001). This decrease was pronounced in thin-cap fibroatheromas (TCFAs), thick-cap fibroatheromas, mixed plaques, and fibrous plaques. The prevalence of TCFAs decreased from 3.4% to 3.3% (P<0.001), whereas that of thick-cap fibroatheromas also decreased from 35% to 33% (P<0.001). Patients with TCFA had a significantly higher risk of ischemia-driven non-target vessel revascularization (hazard ratio [HR], 2.42; 95% CI, 1.03–5.71; P=0.04), primarily due to revascularization in the imaged region. The higher prevalence of fibroatheroma was associated with a numerically increased risk of imaged region revascularization (HR per 10%, 1.38; 95% CI, 0.97–1.97; P=0.07). The prevalence of coronary artery calcium significantly increased from 31% at baseline to 34% at 1-year follow-up (P<0.001), accompanied by a significant increase in calcium thickness and angle. Diabetes and current smoking habits were independently associated with increasing calcium prevalence. No significant association was observed between the prevalence of coronary artery calcium and clinical outcomes within 3 years. Conclusions Coronary artery lumen area significantly decreased over a 1-year interval, particularly in TCFAs, thick-cap fibroatheromas, mixed plaques, and fibrous plaques. Although no significant association was noted between coronary artery calcium prevalence and clinical outcomes within 3 years, the interaction between calcium progression and long-term clinical events necessitates further investigation.

Prognostic value of quantitative anatomical and functional measures of coronary artery disease in diabetic and non-diabetic patients

Abstract Background Diabetes is associated with increased risk of coronary artery disease (CAD). However, the relative prognostic importance of anatomical and functional findings of CAD in the presence vs. absence of diabetes is incompletely understood. Technological advances have made quantitative analysis of coronary artery plaques and stenosis feasible by coronary computed tomography angiography (CTA). In turn, positron emission tomography (PET) enables absolute quantification of myocardial blood flow (MBF). Purpose To study long-term prognostic value of quantified severity of coronary atherosclerosis and myocardial perfusion in non-diabetic vs. diabetic patients with suspected CAD. Methods From two academic medical centres, we identified symptomatic patients with suspected CAD who had undergone coronary CTA and [15O]H2O PET myocardial perfusion imaging during adenosine stress. Based on artificial intelligence -guided quantitative analysis of coronary CTA scans, the anatomical severity of CAD was measured as the presence of obstructive CAD (≥50% diameter stenosis) and percent atheroma volume (PAV; higher vs. lower than median). The functional severity of CAD was measured as the presence of regional myocardial ischemia (≥2 adjacent segments with stress MBF <2.3 ml/g/min) and global stress MBF (<2.2 ml/g/min vs. ≥ 2.2 ml/g/min) by PET. Annual rates of adverse events (AER) including all-cause mortality, myocardial infarction (MI), and unstable angina pectoris (UAP) were evaluated. Results Among 1311 patients, 251 (19%) had diabetes. Patients with diabetes had more frequently obstructive CAD (55% vs. 43%, p<0.001) and regional myocardial ischemia (51% vs. 43%, p=0.015), higher plaque burden by PAV (12% vs. 7%, p<0.001), and lower global stress MBF (2.78 ml/g/min vs. 3.05 ml/g/min, p<0.001). During median follow-up of 7.1 years, 171 (13.0%) patients experienced AE (85 deaths, 56 MIs, and 30 UAPs). Patients with diabetes had higher AER than non-diabetic patients (3.1% vs. 1.6%, p<0.001). The presence of obstructive stenosis was associated with increased AER in non-diabetic (2.6% vs. 1.0%, p<0.001) and diabetic patients (4.2% vs. 1.9%, p<0.001). High plaque burden by PAV was associated with increased AER in non-diabetic (2.8% vs. 0.7%, p<0.001) and diabetic patients (3.9% vs. 1.7%, p<0.001). The presence of regional myocardial ischemia was associated with increased AER in non-diabetic (2.5% vs. 1.1%, p<0.001), but not in diabetic patients (3.4% vs. 2.7%, p=0.238). Low global stress MBF was associated with increased AER in non-diabetic (2.9% vs. 1.3%, p<0.001), but not among diabetic patients (3.2% vs. 3.0%, p=0.286). Conclusions Diabetes was associated with more advanced CAD. Quantified severity of anatomical findings predicted long-term adverse outcome in non-diabetic and diabetic patients. In contrast, functional imaging risk stratified non-diabetic patients, whereas diabetic patients had impaired long-term outcome irrespective of perfusion findings.

Clustering of artificial intelligence derived plaque features for risk stratification for future atrial fibrillation development

Abstract Introduction We previously demonstrated that artificial intelligence (AI)-derived coronary artery plaque features are associated with future development of atrial fibrillation (AF) among patients undergoing CCTA(1). Our results suggest that phenotyping a large dataset of plaque features using data science techniques may reveal associations not visible from univariate analysis. Purpose Use data science analysis of AI-CT plaque characteristics to identify subpopulations at higher risk of AF. Methods We applied dimensionality reduction and visual cluster identification to phenotype our population of patients based on their AI-CT plaque features. We used a single center CCTA registry of patients with prior clinically-indicated CCTA (N=2700) from 2017-2020. Cases of new AF were defined by onset of AF on ECG or telemetry after CCTA via EMR search. Patients with AF prior to CCTA, history of mitral valve surgery, or postoperative AF were excluded. Controls were selected 1:1 by nearest neighbor propensity matching (R. v. 4.0.3.) based on age, sex, tobacco use, HTN, HLD, and diabetes. Atherosclerotic plaques were quantitatively analyzed using a commercially available FDA-approved AI coronary analysis software yielding stenosis area and diameter, remodeling index, volume of calcified/non-calcified/low-density plaques, and number of 2 or more high risk plaques. Uniform Manifold Approximation and Projection (UMAP) dimensionality reduction with cosine distance metric was used to reduce the plaque feature space from 80 dimensions (8 AI measurements per each of 10 anatomical vessel segments in all patients) to 2 dimensions on a scatter plot. Two non-contiguous clusters (i.e. plaque phenotypes) were identified based on visual analysis of UMAP feature reduction (Figure 1). Results 94 cases comprised the study cohort (47 cases and 47 controls). Mean age was 67±11 years. 38% were female. Mean CADRADS score was 1.8±1.52 and mean CAC was 325±622. Mean time from CT to AF was 281±300 days. The majority of AF patients (67%) fell into Cluster 1 (N=36), while Cluster 2 (N=58) contained most of the control subjects (75%). Treating Cluster 1 as a predictor of AF, the PPV and specificity of the UMAP reduction was 67% and 75% respectively, with NPV of 60% and sensitivity of 51% (Table 1). Left atrial volume index (LAVI) was significantly different between the 2 clusters, with mean 56.15±12.42 ml/m2 in Cluster 1 and 46.96±16.03 in Cluster 2 (p=0.0046). LAVI was also significantly different between control subjects in Cluster 1 vs 2, mean 54.84±11.6 vs 41.62±7.92 (p<0.001). Conclusions We demonstrated that UMAP-derived clustering of AI-CT plaque characteristics identifies novel phenotypes for future risk of AF among patients undergoing CCTA. Further, control patients in Cluster 1 were found to have a significantly higher LAVI compared to control subjects in Cluster 2, which supports that membership in Cluster 1 may increase risk of future development of AF.

Coronary artery plaque characteristics in smokers assessed by intracoronary multi-modality imaging: a NIRS-IVUS guided PROSPECT II substudy

Abstract Background Smoking is a risk factor for coronary artery disease and myocardial infarction. Purpose Among patients with myocardial infarction, we hypothesized smokers would have increased prevalence of nonculprit high-risk plaque characteristics as assessed by intracoronary multimodality imaged when compared to nonsmokers. Method This is a prespecified post-hoc analysis of the PROSPECT II (Providing Regional Observations to Study Predictors of Events in the Coronary Tree). Altogether 898 patients with acute myocardial infarction with or without ST-segment elevation who after successful percutaneous coronary intervention had near-infrared spectroscopy and intravascular ultrasound imaging performed. Data on lesion location, plaque burden, and lipid content were collected. Current, former, and nonsmokers were examined regarding the presence of high-risk plaques in both culprit and nonculprit lesions as well as plaque location. High-risk plaque characteristics were defined as a maximum plaque burden (maxPB) of ≥70% and a maximum 4 mm lipid core burden index (maxLCBI4mm) of ≥324.7. Results Out of 886 patients with known smoking history, 32% were smokers, 32% former, and 37% nonsmokers. Smokers were younger (median age: smokers 59.0; former 65.5; nonsmokers 64.0 years, p<0.001) with fewer co-morbidities and presented more often with STEMI (% presenting with STEMI: smokers 22.2%; former 18.9%; nonsmokers 19.4%, p=0.006). LDL was similar but CRP was higher in smokers (median µg/mL: smokers 4.0; former 3.1; nonsmokers 2.9, p=0.004). In multivariate models of nonculprit lesion morphology smoking history was not associated with maxPB or maxLCBI4mm but was associated with presence of calcified nodules (OR: 2.88 (95% CI 1.46–5.69) p=0.002 [smokers vs nonsmokers]). Calcified nodules were also associated with number of years smoked (OR: 1.02 (95% CI 1.01–1.03) p=0.004). Smoking was not associated with presence of ≥1 lesions with MaxLCBI4mm, ≥ 324.7, maxPB >=70% or the combination of both. Smoking was not associated with presence of plaque rupture or thrombus. Right coronary artery culprit lesions were more common in smokers and former smokers (smokers 29.9%; former 30.9%; nonsmokers 21.6%; OR: 1.12 (95% CI 1.04–1.21) p<0.001 [smokers vs nonsmokers]). Conclusion In this prospective intracoronary multimodality imaging study of patients with recent acute myocardial infarction, smoking was not associated with a higher rate of high-risk nonculprit plaques based on lipid content by NIRS or PB by IVUS when compared to former or nonsmokers. However, smoking was associated with higher presence of IVUS-detected calcified nodules, higher CRP-levels, and the right coronary artery as it angiographically was a more common site for culprit lesions. These results indicate that the elevated risk in smokers is unrelated to vulnerable plaque morphology defined by high PB and lipid content, and instead possibly related to inflammation, calcification, or hemodynamic changes.Table 1

The association between mammographic breast density, epicardial adipose tissue volume and coronary artery disease

Abstract Background Dysfunctional adipose tissue is strongly linked to cardiometabolic disease. Epicardial adipose tissue (EAT) which is measurable on cardiac computed tomography (CT) is well correlated with cardiovascular disease (CVD), however it is not reported clinically. Breast mammography mandates reporting of breast density (BD), which is also a marker of breast adipose tissue quantity with less dense breasts indicating greater adipose tissue volume. Given the widespread use of screening mammography, this presents an opportunity to employ BD as a possible surrogate for CVD risk. Purpose To evaluate the correlation between BD, EAT and coronary artery disease (CAD). Methods Single-centre, retrospective, cross-sectional study, including women who had both clinically indicated coronary computed tomography angiogram (CCTA) and mammography. Epicardial adipose tissue volume (EATv) was quantified using semi-automated software (QFAT 2.0). BD was visually assessed by standard 4-level Breast Imaging-Reporting and Data System (BI-RADS) grade with grade A-B representing low density, and C-D representing high density. CAD was categorised as presence/absence of any coronary artery plaque, and CAD severity was quantified using the Coronary Artery Disease Reporting and Data Systems (CAD-RADS) score, with CAD-RADS 1-2 representing mild disease, CAD-RADS 3 moderate disease and CAD-RADS 4 severe disease. CAD analyses were adjusted for modifiable (hypertension, dyslipidaemia, diabetes, body mass index) and non-modifiable (age, past smoking, family history, breast cancer) risk factors. Logistic regression was performed with results presented as Odds Ratio (OR) and [95% Confidence Intervals]. Results Among 153 patients (mean age 62±10), 103 (67.3%) had low BD (high breast adiposity). Compared with high BD, low BD patients were older, had greater rates of hypertension, had significantly higher mean EAT (106.6 ± 43.0 vs 81.0 ± 31.6ml, p<0.001) (Figure 1), and body mass index (30.5 ± 6.3 vs 26.4 ± 5.4kg/m², p<0.001). Adjusted for age and hypertension, EATv remained independently predictive of low BD (OR:1.02 [1.01-1.03], p=0.006). Low BD made up a higher proportion of mild (76.5%), moderate (73.9%) and severe (80.0%) disease. Low BD was strongly associated with presence of CAD (prevalence 75% vs 48%, OR 3.21 [1.58-6.53], p=0.001) independent of EATv (p=0.25), and independent of modifiable (OR: 2.69 [1.24-5.92], p=0.012) and non-modifiable (OR: 2.42 [1.04-5.85], p=0.047) risk factors (Figure 2). Conclusions Low breast density is associated with higher EATv and independently associated with CAD presence beyond EATv and other risk factors. Consequently, mammographic breast density may act as an early risk identification tool for CAD in women.

Coronary plaque volume burden and composition in patients with non-hemodynamically significant coronary artery plaques and systemic inflammation

Abstract Introduction Atherosclerotic coronary disease is a leading cause of morbidity and mortality worldwide. Systemic inflammation can affect plaque composition and thus increase cardiovascular risk. Identifying plaque characteristics in these patients could be useful to learn how inflammation (identified by easy to access parameters, like high ferritin and CRP) affects plaque composition in these challenging patients. Purpose We aimed to evaluate the association of systemic inflammation identified by high ferritin and/or high C-reactive protein (CRP) with coronary plaque volume and composition in patients with non-hemodynamically significant coronary artery plaques (stenosis <50%). Methods We prospectively recruited 109 patients referred for noninvasive CT angiography (from November 2023 to January 2024) with suspected coronary artery disease. 20 had totally/partially non-calcified, non-significant coronary plaques (stenosis <50%). Plaque volume was measured. Plaque components were stablished as calcified (>200 UH), lipidic (<60 UH) and fibrous (60-200 UH). Systemic inflammation was identified when ferritin was >300 ng/mL and/or C-reactive protein CRP was >5 mg/L, according to our laboratory high normal limits. CT scan images were acquired with a 128 detectors dual-layer CT scan with prospective-retrospective/synchronization. Intravascular iodine-based contrast agent was administered. Results Mean age was 60 ± 11 years old and 75% of patients were men. 55% had high blood pressure, 65% were current or previous smokers and 40% had dyslipidemia (35% received statins). 10% were diabetic. There were no difference between groups for these characteristics. We analyzed 33 plaques. Fibrous plaque volume was found to be significantly higher in patients with high ferritin (66.9 vs 32.5 mm3; p = 0.04) and in patients with high CRP (78.7 vs 36.4 mm3; p = 0.05). The percentage of fibrous plaque tended to be higher in patients with higher ferritin and CRP (54.9 vs 38.9; p = 0.06 and 60.6 vs 40.7%; p = 0.07, respectively). Conclusions Systemic inflammation affecting coronary plaque composition in non-hemodynamically significant coronary atherosclerotic disease can by identified by high ferritin and high CRP levels. It is associated with higher fibrous plaque volumes. This finding suggest that systemic inflammation can associate more vulnerable plaques and might benefit from more aggressive management of non-hemodynamically significant atherosclerosis.TableFigure

Impact of hypertension on coronary artery plaques and FFR-CT in type 2 diabetes mellitus patients: evaluation utilizing artificial intelligence processed coronary computed tomography angiography.

This study utilized artificial intelligence (AI) to quantify coronary computed tomography angiography (CCTA) images, aiming to compare plaque characteristics and CT-derived fractional flow reserve (FFR-CT) in type 2 diabetes mellitus (T2DM) patients with or without hypertension (HTN). A retrospective analysis was conducted on 1,151 patients with suspected coronary artery disease who underwent CCTA at a single center. Patients were grouped into T2DM (n = 133), HTN (n = 442), T2DM (HTN+) (n = 256), and control (n = 320). AI assessed various CCTA parameters, including plaque components, high-risk plaques (HRPs), FFR-CT, severity of coronary stenosis using Coronary Artery Disease Reporting and Data System 2.0 (CAD-RADS 2.0), segment involvement score (SIS), and segment stenosis score (SSS). Statistical analysis compared these parameters among groups. The T2DM (HTN+) group had the highest plaque volume and length, SIS, SSS, and CAD-RADS 2.0 classification. In the T2DM group, 54.0% of the plaque volume was noncalcified and 46.0% was calcified, while in the HTN group, these values were 24.0 and 76.0%, respectively. The T2DM (HTN+) group had more calcified plaques (35.7% noncalcified, 64.3% calcified) than the T2DM group. The average necrotic core volume was 4.25 mm3 in the T2DM group and 5.23 mm3 in the T2DM (HTN+) group, with no significant difference (p > 0.05). HRPs were more prevalent in both T2DM and T2DM (HTN+) compared to HTN and control groups (p < 0.05). The T2DM (HTN+) group had a higher likelihood (26.1%) of FFR-CT ≤0.75 compared to the T2DM group (13.8%). FFR-CT ≤0.75 correlated with CAD-RADS 2.0 (OR = 7.986, 95% CI = 5.466-11.667, cutoff = 3, p < 0.001) and noncalcified plaque volume (OR = 1.006, 95% CI = 1.003-1.009, cutoff = 29.65 mm3, p < 0.001). HRPs were associated with HbA1c levels (OR = 1.631, 95% CI = 1.387-1.918). AI analysis of CCTA identifies patterns in quantitative plaque characteristics and FFR-CT values. Comorbid HTN exacerbates partially calcified plaques, leading to more severe coronary artery stenosis in patients with T2DM. T2DM is associated with partially noncalcified plaques, whereas HTN is linked to partially calcified plaques.

Serial Optical Coherence Tomography Assessment of Coronary Atherosclerosis and Long-Term Clinical Outcomes.

The impact of high-risk coronary artery plaques identified using optical coherence tomography on late luminal narrowing and clinical events remains poorly understood. This multicenter prospective study included 176 patients who underwent percutaneous coronary intervention and serial optical coherence tomography at baseline and 1-year follow-up to investigate nontarget regions with angiographically intermediate stenosis. At 1 year after percutaneous coronary intervention, the coronary artery lumen area decreased significantly from 6.06 (95% CI, 5.60-6.53) mm2 to 5.88 (95% CI, 5.41-6.35) mm2 (difference, -0.18; 95% CI, -0.22 to -0.14 mm2; P<0.001), particularly in thin-cap fibroatheromas, thick-cap fibroatheromas, mixed plaques, and fibrous plaques. The prevalence of fibroatheroma decreased from 38% to 36% (P<0.001), whereas calcified plaque increased from 31% to 34% (P<0.001), accompanied by a significant increase in calcium thickness and angle. Diabetes and current smoking habits were independently associated with increasing calcium prevalence. Patients with thin-cap fibroatheroma had a significantly higher 3-year risk of ischemia-driven nontarget vessel revascularization (hazard ratio, 2.42 [95% CI, 1.03-5.71]; P=0.04), primarily due to revascularization in the imaged region. No significant association was observed between coronary artery calcium prevalence and clinical outcomes within 3 years. The coronary artery lumen area significantly decreased over a 1-year interval, particularly in thin-cap fibroatheromas, thick-cap fibroatheromas, mixed plaques, and fibrous plaques. Although thin-cap fibroatheroma prevalence was associated with higher risk of ischemia-driven nontarget vessel revascularization, no significant association was noted between coronary artery calcium prevalence and clinical outcomes within 3 years. The interaction between calcium progression and long-term clinical events necessitates further investigation. URL: https://www.umin.ac.jp/ctr/; Unique Identifier: UMIN000031937.

The role of artificial intelligence in coronary CT angiography.

Coronary CT angiography (CCTA) offers an efficient and reliable tool for the non-invasive assessment of suspected coronary artery disease through the analysis of coronary artery plaque and stenosis. However, the detailed manual analysis of CCTA is aburdensome task requiring highly skilled experts. Recent advances in artificial intelligence (AI) have made significant progress toward amore comprehensive automated analysis of CCTA images, offering potential improvements in terms of speed, performance and scalability. This work offers an overview of the recent developments of AI in CCTA. We cover methodological advances for coronary artery tree and whole heart analysis, and provide an overview of AI techniques that have shown to be valuable for the analysis of cardiac anatomy and pathology in CCTA. Finally, we provide ageneral discussion regarding current challenges and limitations, and discuss prospects for future research.

2-Hydroxypropyl-Β-Cyclodextrin Reduces Atherosclerotic Plaques in Human Coronary Artery

2-Hydroxypropyl-Β-Cyclodextrin Reduces Atherosclerotic Plaques in Human Coronary Artery

TCT-722 Coronary Artery Plaque Distribution in Functional Focal and Diffuse Disease

TCT-722 Coronary Artery Plaque Distribution in Functional Focal and Diffuse Disease