Coronary atherosclerosis in outlier subjects at the opposite extremes of traditional risk factors: Rationale and preliminary results of the Coronary Atherosclerosis in outlier subjects: Protective and novel Individual Risk factors Evaluation (CAPIRE) study

Ascending Aorta 4D Time to Peak Distention Sexual Dimorphism and Association with Coronary Plaque Burden Severity in Women

Coronary artery disease (CAD) risk and plaque scores are often subjective and biased, particularly in mid-age asymptomatic women, whose CAD risk assessment has been historically underestimated. In this study, a new automatic ascending aorta time-to-peak-distention (TPD) analysis was developed for fast screening and as an independent surrogate for subclinical atherosclerosis in asymptomatic women. CCTA was obtained in 50 asymptomatic adults. Plaque burden segment involvement score (SIS) and automatic TPD were obtained from all subjects. Logistic regression analyses were performed to investigate the association between CAD risk scores and TPD with severe coronary plaque burden (SIS>5). TPD, individually, was found to be a significant predictor of SIS>5. Additionally, sex was a significant effect modifier of TPD, with a stronger statistically significant association with women. Four-dimensional aortic time-to-peak distention could supplement conventional CCTA analysis and offer a quick objective screening tool for plaque burden severity and CAD risk stratification, especially in women.

Use of coronary artery calcium score and coronary CT angiography to guide cardiovascular prevention and treatment

Currently, cardiovascular risk stratification to guide preventive therapy relies on clinical scores based on cardiovascular risk factors. However, the discriminative power of these scores is relatively modest. The use of coronary artery calcium score (CACS) and coronary CT angiography (CCTA) has surfaced as methods for enhancing the estimation of risk and potentially providing insights for personalized treatment in individual patients. CACS improves overall cardiovascular risk prediction and may be used to improve the yield of statin therapy in primary prevention, and possibly identify patients with a favorable risk/benefit relationship for antiplatelet therapies. CCTA holds promise to guide anti-atherosclerotic therapies and to monitor individual response to these treatments by assessing individual plaque features, quantifying total plaque volume and composition, and assessing peri-coronary adipose tissue. In this review, we aim to summarize current evidence regarding the use of CACS and CCTA for guiding lipid-lowering and antiplatelet therapy and discuss the possibility of using plaque burden and plaque phenotyping to monitor response to anti-atherosclerotic therapies.

IgG N-Glycosylation Is Altered in Coronary Artery Disease

Coronary artery disease (CAD) is the most common cardiovascular disease (CVD), and previous studies have shown a significant association between N-glycosylation, a highly regulated posttranslational modification, and the development of atherosclerotic plaques. Our aim was to determine whether the N-glycome of immunoglobulin G (IgG) is associated with CAD, as N-glycans are known to alter the effector functions of IgG, which may enhance the inflammatory response in CAD. Therefore, in this study, we isolated IgG from subjects with coronary atherosclerosis (CAD+) and from subjects with clean coronaries (CAD-). The purified IgGs were denatured and enzymatically deglycosylated, and the released and fluorescently labelled N-glycans were analysed by ultra-high performance liquid chromatography based on hydrophilic interactions with fluorescence detection (HILIC-UHPLC-FLR). Sex-stratified analysis of 316 CAD- and 156 CAD+ cases revealed differences in IgG N-glycome composition. The most notable differences were observed in women, where the presence of sialylated N-glycan structures was negatively associated with CAD. The obtained chromatograms provide insight into the IgG N-glycome composition in CAD as well as the biomarker potential of IgG N-glycans in CAD.

Predictive value of HDL function in patients with coronary artery disease: relationship with coronary plaque characteristics and clinical events

BACKGROUND

HDL is endowed with several metabolic, vascular, and immunoinflammatory protective functions. Among them, a key property is to promote reverse cholesterol transport from cells back to the liver. The aim of this study was to estimate the association of scavenger receptor class B type I (SR-BI)- and ATP binding cassette transporter A1 (ABCA1)-mediated cholesterol efflux (the two major routes for cholesterol efflux to HDL) with the presence, extent, and severity of coronary artery disease (CAD), vascular wall remodelling processes, coronary plaque characteristics, and the incidence of myocardial infarction in the different subgroups of patients from the CAPIRE study.

METHODS

Patients (n = 525) from the CAPIRE study were divided into two groups: low-risk factors (RF), with 0-1 RF (n = 263), and multiple-RF, with ≥2 RFs; within each group, subjects were classified as no-CAD or CAD based on the segment involvement score (SIS) evaluated by coronary computed tomography angiography (SIS = 0 and SIS > 5, respectively). SR-BI- and ABCA1-mediated cholesterol efflux were measured using the plasma of all patients.

RESULTS

SR-BI-mediated cholesterol efflux was significantly reduced in patients with CAD in both the low-RF and multiple-RF groups, whereas ABCA1-mediated cholesterol efflux was similar among all groups. In CAD patients, multivariable analysis showed that SR-BI-mediated cholesterol efflux <25^th percentile predicted cardiovascular outcome (odds ratio 4.1; 95% CI: 1.3-13.7; p = .019), whereas ABCA-1-mediated cholesterol efflux and HDL-C levels significantly did not. Despite this finding, reduced SR-BI-mediated cholesterol efflux was not associated with changes in high-risk plaque features or changes in the prevalence of elevated total, non-calcified, and low-attenuation plaque volume.

CONCLUSION

SR-BI-mediated cholesterol efflux capacity is lower in patients with diffuse coronary atherosclerosis. In addition, a lower SR-BI-mediated cholesterol efflux capacity is associated with the worst clinical outcomes in patients with CAD, independently of atherosclerotic plaque features. Key MessagesIncreased cholesterol efflux capacity, an estimate of HDL function, is associated with a reduced CVD risk, regardless of HDL-C levels.HDL-C levels are significantly lower in patients with CAD.Lower SR-BI-mediated cholesterol efflux capacity is observed in patients with diffuse coronary atherosclerosis and is associated with the worst clinical outcomes in patients with CAD, independently of atherosclerotic plaque features.

Osteopontin as Candidate Biomarker of Coronary Disease despite Low Cardiovascular Risk: Insights from CAPIRE Study

Stratification according high cardiovascular (CV) risk categories, still represents a clinical challenge. In this analysis of the CAPIRE study (NCT02157662), we investigate whether inflammation could fit between CV risk factors (RFs) and the presence of coronary artery disease (CAD). In total, 544 patients were included and categorized according with the presence of CAD and CV risk factor burden (low/multiple). The primary endpoint was to verify any independent association of neutrophil-related biomarkers with CAD across CV risk categories. The highest values of osteopontin (OPN) were detected in the low RF group and associated with CAD (23.2 vs. 19.4 ng/mL; p = 0.001), although no correlation with plaque extent and/or composition were observed. Conversely, myeloperoxidase (MPO) and resistin did not differ by CAD presence. Again, OPN was identified as independent variable associated with CAD but only in the low RF group (adjOR 8.42 [95% CI 8.42-46.83]; p-value = 0.015). As an ancillary finding, a correlation linked OPN with the neutrophil degranulation biomarker MPO (r = 0.085; p = 0.048) and resistin (r = 0.177; p = 3.4 × 10-5). In the present study, OPN further strengthens its role as biomarker of CAD, potentially bridging subclinical CV risk with development of atherosclerosis.

Differential Proteomics of Cardiovascular Risk and Coronary Artery Disease in Humans

Background

Proteomics of atypical phenotypes may help unravel cardiovascular disease mechanisms.

Aim

We aimed to prospectively screen the proteome of four types of individuals: with or without coronary artery disease (CAD), each with or without multiple risk factors. Associations with individual risk factors and circulating biomarkers were also tested to provide a functional context to the protein hits.

Materials and Methods

The CAPIRE study (ClinicalTrials.gov Identifier: NCT02157662) is a cross-sectional study aimed at identifying possible new mechanisms promoting or protecting against atherothrombosis. Quantification (by aptamer technology), ranking (using partial least squares), and correlations (by multivariate regression) of ~5000 plasma proteins were performed in consecutive individuals aged 45–75 years, without previous cardiovascular disease, undergoing computed tomography angiography for suspected CAD, showing either &gt;5/16 atherosclerotic segments (CAD+) or completely clean arteries (CAD−) and either ≤ 1 risk factor (RF+) or ≥3 risk factors (RF−) (based on history, blood pressure, glycemia, lipids, and smoking).

Results

Of 544 individuals, 39% were atypical (93 CAD+/RF−; 120 CAD−/RF+) and 61% typical (102 CAD+/RF+; 229 CAD−/RF−). In the comparison with CAD+/RF− adjusted for sex and age, CAD−/RF+ was associated with increased atrial myosin regulatory light chain 2 (MYO) and C-C motif chemokine-22 (C-C-22), and reduced protein shisa-3 homolog (PS-3) and platelet-activating factor acetylhydrolase (PAF-AH). Extending the analysis to the entire cohort, an additional 8 proteins were independently associated with CAD or RF; by logistic regression, the 12-protein panel alone discriminated the four groups with AUCROC's of 0.72–0.81 (overall p = 1.0e−38). Among them, insulin-like growth factor binding protein-3 is positively associated with RF, lower BMI, and HDL-cholesterol, renin with CAD higher glycated hemoglobin HbA1c, and smoking.

Conclusions

In a CCTA-based cohort, four proteins, involved in opposing vascular processes (healing vs. adverse remodeling), are specifically associated with low CAD burden in high CV-risk individuals (high MYO and C-C-22) and high CAD burden in low-risk subjects (high PS-3 and PAF-AH), in interaction with BMI, smoking, diabetes, HDL-cholesterol, and HbA1c. These findings could contribute to a deeper understanding of the atherosclerotic process beyond traditional risk profile assessment and potentially constitute new treatment targets.

Why Do High-Risk Patients Develop or Not Develop Coronary Artery Disease? Metabolic Insights from the CAPIRE Study

Traditional cardiovascular (CV) risk factors (RFs) and coronary artery disease (CAD) do not always show a direct correlation. We investigated the metabolic differences in a cohort of patients with a high CV risk profile who developed, or did not develop, among those enrolled in the Coronary Atherosclerosis in Outlier Subjects: Protective and Novel Individual Risk Factors Evaluation (CAPIRE) study. We studied 112 subjects with a high CV risk profile, subdividing them according to the presence (CAD/High-RFs) or absence of CAD (No-CAD/High-RFs), assessed by computed tomography angiography. The metabolic differences between the two groups were identified by gas chromatography-mass spectrometry. Characteristic patterns and specific metabolites emerged for each of the two phenotypic groups: high concentrations of pyruvic acid, pipecolic acid, p-cresol, 3-aminoisobutyric acid, isoleucine, glyceric acid, lactic acid, sucrose, phosphoric acid, trimethylamine-N-oxide, 3-hydroxy-3-methylglutaric acid, erythritol, 3-hydroxybutyric acid, glucose, leucine, and glutamic acid; and low concentrations of cholesterol, hypoxanthine, glycerol-3-P, and cysteine in the CAD/High-RFs group vs the No-CAD/High-RFs group. Our results show the existence of different metabolic profiles between patients who develop CAD and those who do not, despite comparable high CV risk profiles. A specific cluster of metabolites, rather than a single marker, appears to be able to identify novel predisposing or protective mechanisms towards CAD beyond classic CVRFs.

Plaque quantification by coronary computed tomography angiography using intravascular ultrasound as a reference standard: a comparison between standard and last generation computed tomography scanners

AIMS

The emerging role of coronary computed tomography angiography (CCTA) as a non-invasive tool for atherosclerosis evaluation is supported by data reporting a good correlation between CCTA and intravascular ultrasound (IVUS) for plaque volume quantification. Aim of the present study was to evaluate whether a last generation CT-scanner may improve coronary plaque volume assessment using IVUS as standard-of-reference.

METHODS AND RESULTS

From a registry of 1915 consecutive, all-comers, patients who underwent a clinically indicated IVUS evaluation we enrolled 59 patients who underwent CCTA with a 64-slice CT (Group 1) and 59 patients who underwent CCTA with whole-heart coverage CT scanner (Group 2). Patients who underwent CCTA with unfavourable heart rhythm were not excluded from the analysis. Image quality (4-point Likert scale) focused on plaque analysis was evaluated. Plaque volume quantification by CCTA was compared to IVUS. No difference in clinical characteristics was found between Group 1 and Group 2. Plaque volume quantification by CCTA was considered not feasible in 11 plaques of Group 1 and in 4 plaques of Group 2 (P = 0.09). Higher correlation for plaque volume quantification by CCTA vs. IVUS was demonstrated in Group 2 when compared with Group 1 (r = 0.9888 vs. 0.9499; P < 0.0001). The Bland-Altman analysis showed plaque volume overestimation by CCTA of 11.9 mm3 in Group 1 and 4 mm2 in Group 2 (P < 0.001). Effective radiation dose of CCTA was significantly lower in Group 2 vs. Group 1 (2.7 ± 0.9 vs. 8.1 ± 3.6 mSv, respectively; P < 0.001).

CONCLUSIONS

CCTA using a new scanner generation showed to be an accurate non-invasive tool to assess and quantify coronary plaque volume.

Metabolomic correlates of coronary atherosclerosis, cardiovascular risk, both or neither. Results of the 2 × 2 phenotypic CAPIRE study

BACKGROUND

Traditional cardiovascular risk factors (RFs) and coronary artery disease (CAD) do not always run parallel. We investigated functional-metabolic correlations of CAD, RFs, or neither in the CAPIRE (Coronary Atherosclerosis in Outlier Subjects: Protective and Novel Individual Risk Factors Evaluation) 2 × 2 phenotypic observational study.

METHODS

Two hundred and fortyone subjects were included based on RF burden, presence/absence of CAD (assessed by computed tomography angiography), age and sex. Participants displayed one of four phenotypes: CAD with ≥3 RFs, no-CAD with ≥3 RFs, CAD with ≤1 RF and no-CAD with ≤1 RF. Metabolites were identified by gas chromatography-mass spectrometry and pathways by metabolite set enrichment analysis.

RESULTS

Characteristic patterns and specific pathways emerged for each phenotypic group: amino sugars for CAD/high-RF; urea cycle for no-CAD/high-RF; glutathione for CAD/low-RF; glycine and serine for no-CAD/low-RF. Presence of CAD correlated with ammonia recycling; absence of CAD with the transfer of acetyl groups into mitochondria; high-risk profile with alanine metabolism (all p < 0.05). The comparative case-control analyses showed a statistically significant difference for the two pathways of phenylalanine, tyrosine and tryptophan biosynthesis and phenylalanine metabolism in the CAD/Low-RF vs NoCAD/Low-RF comparison.

CONCLUSIONS

The present 2 × 2 observational study identified specific metabolic pathways for each of the four phenotypes, providing novel functional insights, particularly on CAD with low RF profiles and on the absence of CAD despite high-risk factor profiles.

The Incremental Role of Coronary Computed Tomography in Chronic Coronary Syndromes

In the context of chronic coronary syndromes (CCS), coronary computed tomography angiography (CCTA) has gained broad acceptance as a noninvasive anatomical imaging tool with ability of excluding coronary stenosis with strong negative predictive value. Atherosclerotic plaque lesions are independent predictors of cardiovascular outcomes in high risk patients with known coronary artery disease (CAD). Calcium detection is commonly expressed through the coronary artery calcium score (CACS), but further research is warranted to confirm the powerness of a CACS-only strategy in both diagnosis and prognosis assessment. Recent studies evidence how defined plaque composition characteristics effectively relate to the risk of plaque instabilization and the overall ischemic burden. Fractional flow reserve from CCTA (FFR-CT) has been demonstrated as a reliable method for noninvasive functional evaluation of coronary lesions severity, while the assessment of perfusion imaging under stress conditions is growing as a useful tool for assessment of myocardial ischemia. Moreover, specific applications in procedural planning of transcatheter valve substitution and follow-up of heart transplantation have gained recent importance. This review illustrates the incremental role of CCTA, which can potentially revolutionize the diagnosis and management pathway within the wide clinical spectrum of CCS.

Association of high-risk coronary atherosclerosis at CCTA with clinical and circulating biomarkers: Insight from CAPIRE study

BACKGROUND

High-risk coronary atherosclerosis features evaluated coronary CT angiography (CCTA) were suggested to have a prognostic role. The present study aimed to evaluate the association of circulating biomarkers with high-risk plaque features assessed by CCTA.

METHODS

A consecutive cohort of subjects who underwent CCTA because of suspected CAD was screened for inclusion in the CAPIRE study. Based on risk factors (RF) burden patients were defined as having a low clinical risk (0-1 RF with the exclusion of patients with diabetes mellitus as single RF) or an high clinical risk (≥3 RFs). In all patients, measurement of inflammatory biomarkers and CCTA analysis focused on high-risk plaque features were performed. Univariate and multivariate logistic regression analysis were used to evaluate the relationship between clinical and biological variables with CCTA advanced plaque features.

RESULTS

528 patients were enrolled in CAPIRE study. Older age and male sex appeared to be predictors of qualitative high-risk plaque features and associated with the presence of elevated total, non-calcified and low-attenuation plaque volume. Among circulating biomarkers only hs-CRP was found to be associated with qualitative high-risk plaque features (OR 2.02, p = 0.004 and 2.02, p = 0.012 for LAP and RI > 1.1, respectively) with borderline association with LAP-Vol (OR 1.52, p = 0.076); HbA1c and PTX-3 resulted to be significantly associated with quantitative high-risk plaque features (OR 1.71, p = 0.003 and 1.04, p = 0.002 for LAP-Vol, respectively).

CONCLUSIONS

Our results support the association between inflammatory biomarkers (hs-CRP, PTX- 3), HbA1c and high-risk atherosclerotic features detected by CCTA. Male sex and older age are significant predictors of high-risk atherosclerosis.

Coronary Artery Disease and Type 2 Diabetes: A Proteomic Study

OBJECTIVE

Coronary artery disease (CAD) is a major challenge in patients with type 2 diabetes (T2D). Coronary computed tomography angiography (CCTA) provides a detailed anatomic map of the coronary circulation. Proteomics are increasingly used to improve diagnostic and therapeutic algorithms. We hypothesized that the protein panel is differentially associated with T2D and CAD.

RESEARCH DESIGN AND METHODS

In CAPIRE (Coronary Atherosclerosis in Outlier Subjects: Protective and Novel Individual Risk Factors Evaluation-a cohort of 528 individuals with no previous cardiovascular event undergoing CCTA), participants were grouped into CAD^- (clean coronaries) and CAD⁺ (diffuse lumen narrowing or plaques). Plasma proteins were screened by aptamer analysis. Two-way partial least squares was used to simultaneously rank proteins by diabetes status and CAD.

RESULTS

Though CAD⁺ was more prevalent among participants with T2D (HbA_1c 6.7 ± 1.1%) than those without diabetes (56 vs. 30%, P < 0.0001), CCTA-based atherosclerosis burden did not differ. Of the 20 top-ranking proteins, 15 were associated with both T2D and CAD, and 3 (osteomodulin, cartilage intermediate-layer protein 15, and HTRA1) were selectively associated with T2D only and 2 (epidermal growth factor receptor and contactin-1) with CAD only. Elevated renin and GDF15, and lower adiponectin, were independently associated with both T2D and CAD. In multivariate analysis adjusting for the Framingham risk panel, patients with T2D were "protected" from CAD if female (P = 0.007), younger (P = 0.021), and with lower renin levels (P = 0.02).

CONCLUSIONS

We concluded that 1) CAD severity and quality do not differ between participants with T2D and without diabetes; 2) renin, GDF15, and adiponectin are shared markers by T2D and CAD; 3) several proteins are specifically associated with T2D or CAD; and 4) in T2D, lower renin levels may protect against CAD.

Metabolic profiling reveals the heterogeneity of vascular endothelial function phenotypes in individuals at extreme cardiovascular risk

Maladapted vascular endothelial metabolism in the context of endothelial function differing in phenotype remains unknown, which limits our understanding of the heterogeneous pathogenesis of atherosclerotic cardiovascular disease (CVD). This study aimed to profile serum metabolic alterations of different vascular endothelial function phenotypes in asymptomatic adults at extreme cardiovascular risk. In addition to 12 CVD patients, 103 individuals free of CVD were categorized as having normal endothelial function (NEF) (n = 30), cardiovascular risk-promoting endothelial function (PEF) (n = 18), cardiovascular risk-resistant endothelial function (REF) (n = 25), and vulnerable endothelial function (VEF) (n = 30). Serum metabolic profiles were detected using gas chromatography time-of-flight/mass spectrometry and multivariate statistics. Compared to the NEF group, a total of 17, 17, 22, and 13 differential metabolites were identified in the PEF, REF, VEF, and CVD groups, respectively. Of the altered metabolic pathways, multiple pathways were consistent between the PEF and CVD groups, including pyrimidine metabolism, starch and sucrose metabolism, aminoacyl-tRNA biosynthesis, arginine and proline metabolism, and d-glutamine and d-glutamate metabolism. Notably, a relative increase in low-calorie sugar in galactose metabolism was exclusively found in the REF group, and a relative increase in the ratio of acetyl-CoA to CoA was suggested in the VEF group based on elevated butanoate metabolism and reduced pantothenate and CoA biosynthesis. Our findings clearly indicate distinct metabolic patterns across groups with heterogeneous vascular endothelial function in the context of extreme cardiovascular risk, and improve our understanding of the pathogenic heterogeneity of early CVD in asymptomatic populations.

This metabolomics analysis has revealed the maladapted vascular endothelial metabolism across individuals with heterogeneous vascular endothelial function in the context of extreme cardiovascular risk.