Local Production of Lipoprotein-Associated Phospholipase A 2 and Lysophosphatidylcholine in the Coronary Circulation

Electrochemical impedance spectroscopy unmasks high-risk atherosclerotic features in human coronary artery disease

Coronary plaque rupture remains the prominent mechanism of myocardial infarction. Accurate identification of rupture-prone plaque may improve clinical management. This study assessed the discriminatory performance of electrochemical impedance spectroscopy (EIS) in human cardiac explants to detect high-risk atherosclerotic features that portend rupture risk. In this single-center, prospective study, n = 26 cardiac explants were collected for EIS interrogation of the three major coronary arteries. Vessels in which advancement of the EIS catheter without iatrogenic plaque disruption was rendered impossible were not assessed. N = 61 vessels underwent EIS measurement and histological analyses. Plaques were dichotomized according to previously established high rupture-risk parameter thresholds. Diagnostic performance was determined via receiver operating characteristic areas-under-the-curve (AUC). Necrotic cores were identified in n = 19 vessels (median area 1.53 mm2) with a median fibrous cap thickness of 62 μm. Impedance was significantly greater in plaques with necrotic core area ≥1.75 mm2 versus <1.75 mm2 (19.8 ± 4.4 kΩ vs. 7.2 ± 1.0 kΩ, p = .019), fibrous cap thickness ≤65 μm versus >65 μm (19.1 ± 3.5 kΩ vs. 6.5 ± 0.9 kΩ, p = .004), and ≥20 macrophages per 0.3 mm-diameter high-power field (HPF) versus <20 macrophages per HPF (19.8 ± 4.1 kΩ vs. 10.2 ± 0.9 kΩ, p = .002). Impedance identified necrotic core area ≥1.75 mm2, fibrous cap thickness ≤65 μm, and ≥20 macrophages per HPF with AUCs of 0.889 (95% CI: 0.716-1.000) (p = .013), 0.852 (0.646-1.000) (p = .025), and 0.835 (0.577-1.000) (p = .028), respectively. Further, phase delay discriminated severe stenosis (≥70%) with an AUC of 0.767 (0.573-0.962) (p = .035). EIS discriminates high-risk atherosclerotic features that portend plaque rupture in human coronary artery disease and may serve as a complementary modality for angiography-guided atherosclerosis evaluation.

Peri-coronary fat attenuation index combined with high-risk plaque characteristics quantified from coronary computed tomography angiography for risk stratification in new-onset chest pain individuals without acute myocardial infarction

This study aims to evaluate the role of the peri-coronary Fat Attenuation Index (FAI) and High-Risk Plaque Characteristics (HRPC) in the assessment of coronary heart disease risk. By conducting coronary CT angiography and coronary angiography on 217 patients with newly developed chest pain (excluding acute myocardial infarction), their degree of vascular stenosis, FAI, and the presence and quantity of HRPC were assessed. The study results demonstrate a correlation between FAI and HRPC, and the combined use of FAI and HRPC can more accurately predict the risk of major adverse cardiovascular events (MACE). Additionally, the study found that patients with high FAI were more prone to exhibit high-risk plaque characteristics, severe stenosis, and multiple vessel disease. After adjustment, the combination of FAI and HRPC improved the ability to identify and reclassify MACE. Furthermore, the study identified high FAI as an independent predictor of MACE in patients undergoing revascularization, while HRPC served as an independent predictor of MACE in patients not undergoing revascularization. These findings suggest the potential clinical value of FAI and HRPC in the assessment of coronary heart disease risk, particularly in patients with newly developed chest pain excluding acute myocardial infarction.

Association of adrenal steroids with metabolomic profiles in patients with primary and endocrine hypertension

Introduction

Endocrine hypertension (EHT) due to pheochromocytoma/paraganglioma (PPGL), Cushing's syndrome (CS), or primary aldosteronism (PA) is linked to a variety of metabolic alterations and comorbidities. Accordingly, patients with EHT and primary hypertension (PHT) are characterized by distinct metabolic profiles. However, it remains unclear whether the metabolomic differences relate solely to the disease-defining hormonal parameters. Therefore, our objective was to study the association of disease defining hormonal excess and concomitant adrenal steroids with metabolomic alterations in patients with EHT.

Methods

Retrospective European multicenter study of 263 patients (mean age 49 years, 50% females; 58 PHT, 69 PPGL, 37 CS, 99 PA) in whom targeted metabolomic and adrenal steroid profiling was available. The association of 13 adrenal steroids with differences in 79 metabolites between PPGL, CS, PA and PHT was examined after correction for age, sex, BMI, and presence of diabetes mellitus.

Results

After adjustment for BMI and diabetes mellitus significant association between adrenal steroids and metabolites - 18 in PPGL, 15 in CS, and 23 in PA - were revealed. In PPGL, the majority of metabolite associations were linked to catecholamine excess, whereas in PA, only one metabolite was associated with aldosterone. In contrast, cortisone (16 metabolites), cortisol (6 metabolites), and DHEA (8 metabolites) had the highest number of associated metabolites in PA. In CS, 18-hydroxycortisol significantly influenced 5 metabolites, cortisol affected 4, and cortisone, 11-deoxycortisol, and DHEA each were linked to 3 metabolites.

Discussions

Our study indicates cortisol, cortisone, and catecholamine excess are significantly associated with metabolomic variances in EHT versus PHT patients. Notably, catecholamine excess is key to PPGL's metabolomic changes, whereas in PA, other non-defining adrenal steroids mainly account for metabolomic differences. In CS, cortisol, alongside other non-defining adrenal hormones, contributes to these differences, suggesting that metabolic disorders and cardiovascular morbidity in these conditions could also be affected by various adrenal steroids.

Liposomal-Associated Phospholipase A 2 Is More Effective in Predicting Cardiac Risk in Law Enforcement Than Framingham Risk Score and Coronary Artery Calcium Score Calculation

OBJECTIVE

To clarify the methods for identifying officers at high risk for cardiac events.

METHODS

This retrospective review included 3330 patient charts. Classic cardiovascular risk factors, coronary artery calcium (CAC) scores, and endothelial inflammatory biomarker levels were compared between civilians and law enforcement officers (LEOs). The Framingham Risk Score (FRS) was compared with risk assessment using inflammatory biomarkers.

RESULTS

The FRS failed to identify more than 90% of LEOs at high risk of cardiovascular events. Similarly, the use of the CAC score was ineffective. Inflammatory biomarker analysis measuring the lipoprotein-associated phospholipase A 2 activity was the most reliable method for identifying LEOs at high risk of cardiovascular events.

CONCLUSIONS

The use of the standard FRS and CAC scores is less effective than that of inflammatory biomarkers in identifying LEOs at high risk of cardiovascular events.

Quantitative imaging biomarkers of coronary plaque morphology: insights from EVAPORATE

Aims

Residual cardiovascular risk persists despite statin therapy. In REDUCE-IT, icosapent ethyl (IPE) reduced total events, but the mechanisms of benefit are not fully understood. EVAPORATE evaluated the effects of IPE on plaque characteristics by coronary computed tomography angiography (CCTA). Given the conclusion that the IPE-treated patients demonstrate that plaque burden decreases has already been published in the primary study analysis, we aimed to demonstrate whether the use of an analytic technique defined and validated in histological terms could extend the primary study in terms of whether such changes could be reliably seen in less time on drug, at the individual (rather than only at the cohort) level, or both, as neither of these were established by the primary study result.

Methods and Results

EVAPORATE randomized the patients to IPE 4 g/day or placebo. Plaque morphology, including lipid-rich necrotic core (LRNC), fibrous cap thickness, and intraplaque hemorrhage (IPH), was assessed using the ElucidVivo® (Elucid Bioimaging Inc.) on CCTA. The changes in plaque morphology between the treatment groups were analyzed. A neural network to predict treatment assignment was used to infer patient representation that encodes significant morphological changes. Fifty-five patients completed the 18-month visit in EVAPORATE with interpretable images at each of the three time points. The decrease of LRNC between the patients on IPE vs. placebo at 9 months (reduction of 2 mm3 vs. an increase of 41 mm3, p = 0.008), widening at 18 months (6 mm3 vs. 58 mm3 increase, p = 0.015) were observed. While not statistically significant on a univariable basis, reductions in wall thickness and increases in cap thickness motivated multivariable modeling on an individual patient basis. The per-patient response assessment was possible using a multivariable model of lipid-rich phenotype at the 9-month follow-up, p < 0.01 (sustained at 18 months), generalizing well to a validation cohort.

Conclusion

Plaques in the IPE-treated patients acquired more characteristics of stability. Reliable assessment using histologically validated analysis of individual response is possible at 9 months, with sustained stabilization at 18 months, providing a quantitative basis to elucidate drug mechanism and assess individual patient response.

Non-contrast CT-based radiomics nomogram of pericoronary adipose tissue for predicting haemodynamically significant coronary stenosis in patients with type 2 diabetes

BACKGROUND

Type 2 diabetes mellitus (T2DM) patients have a higher incidence of coronary artery disease than the general population. The aim of this study was to develop a radiomics nomogram of pericoronary adipose tissue (PCAT) based on non-contrast CT to predict haemodynamically significant coronary stenosis in T2DM patients.

METHODS

The study enrolled 215 T2DM patients who underwent non-contrast CT and coronary computed tomography angiography (CCTA). CCTA derived fractional flow reserve (FFR_CT) ≤ 0.80 was defined as hemodynamically significant stenosis.1691 radiomics features were extracted from PCAT on non-contrast CT. Minimum redundancy maximum relevance (mRMR) and least absolute shrinkage and selection operator (LASSO) were used to select useful radiomics features to construct Radscore. Logistic regression was applied to select significant factors among Radscore, fat attenuation index (FAI) and coronary artery calcium score (CACS) to construct radiomics nomogram.

RESULTS

Radscore [odds ratio (OR) = 2.84; P < 0.001] and CACS (OR = 1.00; P = 0.023) were identified as independent predictors to construct the radiomics nomogram. The radiomics nomogram showed excellent performance [training cohort: area under the curve (AUC) = 0.81; 95% CI: 0.76-0.86; validation cohort: AUC = 0.83; 95%CI: 0.76-0.90] to predict haemodynamically significant coronary stenosis in patients with T2DM. Decision curve analysis demonstrated high clinical value of the radiomics nomogram.

CONCLUSION

The non-contrast CT-based radiomics nomogram of PCAT could effectively predict haemodynamically significant coronary stenosis in patients with T2DM, which might be a potential noninvasive tool for screening of high-risk patients.

Banxia Xiexin decoction alleviates AS co-depression disease by regulating the gut microbiome-lipid metabolic axis

ETHNOPHARMACOLOGICAL RELEVANCE

Banxia Xiexin decoction (BXD) is a classic Chinese herbal formulation consisting of 7 herbs including Pinelliae Rhizoma, Scutellariae Radix, Zingiberis Rhizoma, Ginseng Radix, Glycyrrhizae Radix, Coptidis Rhizoma, and Jujubae Fructus, which can exert effects on lowering lipids and alleviating depressive mood disorders via affecting gastrointestinal tract.

AIM OF THE STUDY

The pathogenesis of atherosclerosis (AS) co-depression disease has not been well studied, and the current clinical treatment strategies are not satisfactory. As a result, it is critical to find novel methods of treatment. Based on the hypothesis that the gut microbiome may promote the development of AS co-depression disease by regulating host lipid metabolism, this study sought to evaluate the effectiveness and action mechanism of BXD in regulation of the gut microbiome via an intervention in AS co-depression mice.

MATERIALS AND METHODS

To determine the primary constituents of BXD, UPLC-Q/TOF-MS analysis was carried out. Sixteen C56BL/6 mice were fed normal chow as a control group; 64 ApoE^-/- mice were randomized into four groups (model group and three treatment groups) and fed high-fat chow combined with daily bind stimulation for sixteen weeks to develop the AS co-depression mouse model and were administered saline or low, medium or high concentrations of BXD during the experimental modeling period. The antidepressant efficacy of BXD was examined by weighing, a sucrose preference test, an open field test, and a tail suspension experiment. The effectiveness of BXD as an anti-AS treatment was evaluated by means of biochemical indices, the HE staining method, and the Oil red O staining method. The impacts of BXD on the gut microbiome structure and brain (hippocampus and prefrontal cortex tissue) lipids in mice with the AS co-depression model were examined by 16S rDNA sequencing combined with lipidomics analysis.

RESULTS

The main components of BXD include baicalin, berberine, ginsenoside Rb1, and 18 other substances. BXD could improve depression-like behavioral characteristics and AS-related indices in AS co-depression mice; BXD could regulate the abundance of some flora (phylum level: reduced abundance of Proteobacteria and Deferribacteres; genus level: reduced abundance of Clostridium_IV, Helicobacter, and Pseudoflavonifractor, Acetatifactor, Oscillibacter, which were significantly different). The lipidomics analysis showed that the differential lipids between the model and gavaged high-dose BXD (BXH) groups were enriched in glycerophospholipid metabolism, and lysophosphatidylcholine (LPC(20:3)(rep)(rep)) in the hippocampus and LPC(20:4)(rep) in the prefrontal cortex both showed downregulation in BXH. The correlation analysis illustrated that the screened differential lipids were mainly linked to Deferribacteres and Actinobacteria.

CONCLUSION

BXD may exert an anti-AS co-depression therapeutic effect by modulating the abundance of some flora and thus intervening in peripheral lipid and brain lipid metabolism (via downregulation of LPC levels).

Radiomics features of pericoronary adipose tissue improve CT-FFR performance in predicting hemodynamically significant coronary artery stenosis

OBJECTIVES

To evaluate the value of radiomics-based model of pericoronary adipose tissue (PCAT) combined with CT fractional flow reserve (CT-FFR) in predicting hemodynamically significant coronary stenosis.

METHODS

Patients with suspected or known coronary artery disease, who had coronary computed tomography angiography (CCTA), invasive coronary angiography (ICA), and FFR within 1 month, were retrospectively included. Radiomics features of lesion-based PCAT were extracted. The lesion-specific CT-FFR values, CCTA-derived diameter stenosis, lesion length, and PCAT attenuation were also measured. FFR values were used as the reference standard to assess the diagnostic performance of radiomics model, CT-FFR, and combined model for detection of flow-limiting stenosis.

RESULTS

A total of 146 patients with 180 lesions were included in the study. All lesions were divided into training and validation cohorts at a ratio of 2:1. CT-FFR model exhibited the highest area under the curve (AUC) (0.803 for training, 0.791 for validation) in predicting hemodynamically significant stenosis, followed by radiomics model (0.776 for training, 0.744 for validation). However, no statistically significant difference was found between the AUCs of the above two models (p > 0.05). When CT-FFR was combined with radiomics model, the AUC reached 0.900 for training cohort and 0.875 for validation cohort, which were significantly higher than that of CT-FFR and radiomics model alone (both p < 0.05).

CONCLUSION

The diagnostic performance of PCAT radiomics model was comparable to that of CT-FFR for identification of ischemic coronary stenosis. Adding PCAT radiomics model to CT-FFR showed incremental value in discriminating flow-limiting from non-flow-limiting lesions.

KEY POINTS

• Radiomics analysis of lesion-based PCAT is potentially an alternative method to identify hemodynamic significance of coronary artery stenosis. • Adding radiomics model of PCAT to CT-FFR improved diagnostic performance for the detection of flow-limiting coronary stenosis. • Radiomics features + CT-FFR is a promising noninvasive method for comprehensive evaluation of hemodynamic significance of coronary artery stenosis.

Impact of coronary disease patterns, anatomical factors, micro-vascular disease and non-coronary cardiac factors on invasive coronary physiology

Invasive coronary physiology has been applied by interventional cardiologists to guide the management of coronary artery disease (CAD), with well-defined thresholds applied to determine whether CAD should be managed with optimal medical therapy (OMT) alone or OMT and percutaneous coronary intervention (PCI). There are multiple modalities in clinical use, including hyperaemic and non-hyperaemic indices. Despite endorsement in the major guidelines, there are various factors which impact and confound the readings of invasive coronary physiology, both within the coronary tree and beyond. This review article aims to summarise the mechanisms by which these factors impact invasive coronary physiology, and distinguish factors that contribute to ischaemia from confounding factors. The potential for mis-classification of ischaemic status is highlighted. Lastly, the authors identify targets for future research to improve the precision of physiology-guided management of CAD.

Fat digestion and metabolism: effect of different fat sources and fat mobilisers in broilers diet on growth performance and physiological parameters – a review

Commercial broilers have a short production cycle and a high requirement for energy (3000 kcal/kg in starter phase and 3200 kcal/kg in finisher phase). Therefore, the need to add energy rich lipids to their diet is inevitable. Digestibility of fat depends on its multiple properties: chain length, the composition of fatty acids, ratio of saturated/unsaturated fatty acids and free fatty acids. The high cost of vegetable oils and less availability due to their consumption in human diet are the main reasons for searching cheaper alternative fat sources. Animal oils like poultry and fish oil are the by-product of rendering plants and after refining, they are used in poultry diets as an energy source. Due to presence of impurities and free fatty acids, the digestibility of animal fat is less. There is a limited amount of bile acids and lipase available during early age and when birds are reared on high energy diet (finisher phase). Supplementation of emusifier or lipase in broilers diet increase fat utilisation. Emulsifiers increase fat digestibility by increasing active surface area of lipid droplets. Lysolecithin and Lysophospholipids are produced from hydrolyses of lecithin and phospholipids by phopholipase A2. The bile acids mainly compose of cholic acid, hyodeoxycholic acid and chenodeoxycholic acid and have strong emulsification properties. Triacylglyceryl acylase (lipase) is an enzyme involved in catalysis and the hydrolysis of lipids. It can be concluded that use of emulsifier and lipase in broilers diet improves growth performance, nutrient digestibility and intestinal histology in broilers.

Relation Between Coronary Plaque Composition Assessed by Intravascular Ultrasound Virtual Histology and Myocardial Ischemia Assessed by Quantitative Flow Ratio

Coronary plaque composition may play an important role in the induction of myocardial ischemia. Our objective was to further clarify the relation between coronary plaque composition and myocardial ischemia in patients with chest pain symptoms. The study population consisted of 103 patients who presented to the outpatient clinic or emergency department with chest pain symptoms and were referred for diagnostic invasive coronary angiography. Intravascular ultrasound virtual histology was used for the assessment of coronary plaque composition. A noncalcified plaque was defined as a combination of necrotic core and fibrofatty tissue. Quantitative flow ratio (QFR), which is a coronary angiography-based technique used to calculate fractional flow reserve without the need for hyperemia induction or for a pressure wire, was used as the reference standard for the evaluation of myocardial ischemia. Coronary artery plaques with QFR of ≤0.80 were considered abnormal-that is, ischemia-generating. In total, 149 coronary plaques were analyzed, 21 of which (14%) were considered abnormal according to QFR. The percentage of noncalcified tissue was significantly higher in plaques with abnormal QFR (38.2 ± 6.5% vs 33.1 ± 9.0%, p = 0.014). After univariable analysis, both plaque load (odds ratio [OR] per 1% increase 1.081, p <0.001) and the percentage of noncalcified tissue (OR per 1% increase 1.070, p = 0.020) were significantly associated with reduced QFR. However, after multivariable analysis, only plaque load remained significantly associated with abnormal QFR (OR per 1% increase 1.072, p <0.001). In conclusion, the noncalcified plaque area was significantly higher in hemodynamically significant coronary lesions than in nonsignificant lesions. Although an increase in the noncalcified plaque area was significantly associated with a reduced QFR, this association lost significance after adjustment for localized plaque load.

Computed Tomography-derived Characterization of Pericoronary, Epicardial, and Paracardial Adipose Tissue and Its Association With Myocardial Ischemia as Assessed by Computed Fractional Flow Reserve

BACKGROUND

Increased pericoronary adipose tissue (PCAT) attenuation derived from coronary computed tomography (CT) angiography (CTA) relates to coronary inflammation and cardiac mortality. We aimed to investigate the association between CT-derived characterization of different cardiac fat compartments and myocardial ischemia as assessed by computed fractional flow reserve (FFRCT).

METHODS

In all, 133 patients (median 64 y, 74% male) with coronary artery disease (CAD) underwent CTA including FFRCT measurement followed by invasive FFR assessment (FFRINVASIVE). CT attenuation and volume of PCAT were quantified around the proximal right coronary artery (RCA), left anterior descending artery (LAD), and left circumflex artery (LCX). Epicardial adipose tissue (EAT) and paracardial adipose tissue (PAT; all intrathoracic adipose tissue outside the pericardium) were quantified in noncontrast cardiac CT datasets.

RESULTS

Median FFRCT was 0.86 [0.79, 0.91] and median FFRINVASIVE was 0.87 [0.81, 0.93]. Subjects with the presence of myocardial ischemia (n=26) defined by an FFRCT-threshold of ≤0.75 showed significantly higher RCA PCAT attenuation than individuals without myocardial ischemia (n=107) (-75.1±10.8 vs. -81.1±10.6 HU, P=0.011). In multivariable analysis adjusted for age, body mass index, sex and risk factors, increased RCA PCAT attenuation remained a significant predictor of myocardial ischemia. Between individuals with myocardial ischemia compared with individuals without myocardial ischemia, there was no significant difference in the volume and CT attenuation of EAT and PAT or in the PCAT volume of RCA, LAD, and LCX.

CONCLUSIONS

Increased RCA PCAT attenuation is associated with the presence of myocardial ischemia as assessed by FFR, while PCAT volume, EAT, and PAT are not.

Machine Learning From Quantitative Coronary Computed Tomography Angiography Predicts Fractional Flow Reserve-Defined Ischemia and Impaired Myocardial Blood Flow

BACKGROUND

A pathophysiological interplay exists between plaque morphology and coronary physiology. Machine learning (ML) is increasingly being applied to coronary computed tomography angiography (CCTA) for cardiovascular risk stratification. We sought to assess the performance of a ML score integrating CCTA-based quantitative plaque features for predicting vessel-specific ischemia by invasive fractional flow reserve (FFR) and impaired myocardial blood flow (MBF) by positron emission tomography (PET).

METHODS

This post-hoc analysis of the PACIFIC trial (Prospective Comparison of Cardiac Positron Emission Tomography/Computed Tomography [CT]' Single Photon Emission Computed Tomography/CT Perfusion Imaging and CT Coronary Angiography with Invasive Coronary Angiography) included 208 patients with suspected coronary artery disease who prospectively underwent CCTA' [15O]H2O PET, and invasive FFR. Plaque quantification from CCTA was performed using semiautomated software. An ML algorithm trained on the prospective NXT trial (484 vessels) was used to develop a ML score for the prediction of ischemia (FFR≤0.80), which was then evaluated in 581 vessels from the PACIFIC trial. Thereafter, the ML score was applied for predicting impaired hyperemic MBF (≤2.30 mL/min per g) from corresponding PET scans. The performance of the ML score was compared with CCTA reads and noninvasive FFR derived from CCTA (FFRCT).

RESULTS

One hundred thirty-nine (23.9%) vessels had FFR-defined ischemia, and 195 (33.6%) vessels had impaired hyperemic MBF. For the prediction of FFR-defined ischemia, the ML score yielded an area under the receiver-operating characteristic curve of 0.92, which was significantly higher than that of visual stenosis grade (0.84; P<0.001) and comparable with that of FFRCT (0.93; P=0.34). Quantitative percent diameter stenosis and low-density noncalcified plaque volume had the greatest ML feature importance for predicting FFR-defined ischemia. When applied for impaired MBF prediction, the ML score exhibited an area under the receiver-operating characteristic curve of 0.80; significantly higher than visual stenosis grade (area under the receiver-operating characteristic curve 0.74; P=0.02) and comparable with FFRCT (area under the receiver-operating characteristic curve 0.77; P=0.16).

CONCLUSIONS

An externally validated ML score integrating CCTA-based quantitative plaque features accurately predicts FFR-defined ischemia and impaired MBF by PET, performing superiorly to standard CCTA stenosis evaluation and comparably to FFRCT.

Importance of plaque volume and composition for the prediction of myocardial ischaemia using sequential coronary computed tomography angiography/positron emission tomography imaging

AIMS

Coronary atherosclerosis with a large necrotic core has been postulated to reduce the vasodilatory capacity of vascular tissue. In the present analysis, we explored whether total plaque volume and necrotic core volume on coronary computed tomography angiography (CCTA) are independently associated with myocardial ischaemia on positron emission tomography (PET).

METHODS AND RESULTS

From a registry of symptomatic patients with suspected coronary artery disease and clinically indicated CCTA with sequential [15O]H2O PET myocardial perfusion imaging, we quantitatively measured diameter stenosis, total and compositional plaque volumes on CCTA. Primary endpoint was myocardial ischaemia on PET, defined as an absolute stress myocardial blood flow ≤2.4 mL/g/min in ≥1 segment. Multivariable prediction models for myocardial ischaemia were consecutively created using logistic regression analysis (stenosis model: diameter stenosis ≥50%; plaque volume model: +total plaque volume; plaque composition model: +necrotic core volume). A total of 493 patients (mean age 63 ± 8 years, 54% men) underwent sequential CCTA/PET imaging. In 153 (31%) patients, myocardial ischaemia was detected on PET. Diameter stenosis ≥50% (P < 0.001) and necrotic core volume (P = 0.029) were independently associated with myocardial ischaemia, while total plaque volume showed borderline significance (P = 0.052). The plaque composition model (χ2 = 169) provided incremental value for the prediction of ischaemia when compared with the stenosis model (χ2 = 138, P < 0.001) and plaque volume model (χ2 = 164, P = 0.021).

CONCLUSION

The volume of necrotic core on CCTA independently and incrementally predicts myocardial ischaemia on PET, beyond diameter stenosis alone.

Increased sedentary time and decreased physical activity increases lipoprotein associated phospholipase A2 in obese individuals

BACKGROUND AND AIMS

Lipoprotein-associated Phospholipase A₂ (Lp-PLA₂) is a protein produced by inflammatory cells in circulation and is associated with cardiovascular disease (CVD) risk. Physical activity (PA) is known to reduce inflammation and risk for CVD. However, Lp-PLA₂ has yet to be examined in relation to PA and sedentary time. The purpose of this study was to determine if PA and sedentary time impacts Lp-PLA₂ mass. A total of 25 subjects with an average BMI of 30.6 ± 5.7 were included in the data analysis.

METHODS AND RESULTS

Data collected included anthropometric data, Lp-PLA₂ mass, peak oxygen uptake (VO₂peak), resting heart rate and blood pressure, obstructive sleep apnea (OSA) risk, and assessment of PA using an accelerometer. Sedentary minutes per day was positively associated with Lp-PLA₂ (r = 0.41, P < 0.05). Light intensity PA was negatively associated (r = -0.51. P = 0.01) with Lp-PLA₂. When subjects were divided into 2-quantiles by Lp-PLA₂, the group with the higher Lp-PLA₂ mass accumulated more sedentary time per day (P < 0.001) and less light intensity PA per day (P = 0.001). OSA risk and Lp-PLA₂ showed no relationship. Sedentary behavior was higher, and light intensity PA was lower in subjects with hiLp-PLA₂ mass. No difference was seen in moderate-to-vigorous intensity PA or steps per day.

CONCLUSIONS

This suggests that, total PA habits, including time spent sedentary and lower intensity PA, impacts the levels of Lp-PLA₂, an important inflammatory marker and marker of CVD risk.

The Perivascular Fat Attenuation Index Improves the Diagnostic Performance for Functional Coronary Stenosis

Background: Coronary computed tomography angiography (CCTA) is an established first-line test in the investigation of patients with suspected coronary artery disease (CAD), while the perivascular fat attenuation index (FAI) derived from CT seems to be a feasible and efficient tool for the identification of ischemia. The association between the FAI and lesion-specific ischemia as assessed by fractional flow reserve (FFR) remains unclear. Methods: In a total of 261 patients, 294 vessels were assessed for CCTA stenosis, vessel-specific FAI, lesion-specific FAI, and plaque characteristics. The diagnostic accuracies of each parameter and the combined approach were analyzed via the receiver operating characteristic curve (ROC) with FFR as the reference standard. The determinants of FAI were statistically analyzed. Results: The cutoff values of vessel-specific FAI and lesion-specific FAI scores calculated according to the Youden index were −70.97 and −73.95 HU, respectively. No significant differences were noted between them; however, they exhibited a strong correlation. No significant differences were noted between the area under the curve (AUC) scores of vessel-specific FAI (0.677), lesion-specific FAI (0.665), and CCTA (0.607) (p > 0.05 for all) results. The addition of two FAI measures to the CCTA showed improvements in the discrimination (AUC) and reclassification ability (relative integrated discrimination improvement (IDI) and category-free net reclassification index (NRI)), vessel-specific FAI (AUC, 0.696; NRI, 49.6%; IDI, 5.9%), and lesion-specific FAI scores (AUC, 0.676; NRI, 43.3%; IDI, 5.4%); (p < 0.01 for all). Multivariate analysis revealed that low-attenuation plaque (LAP) volume was an independent predictor of two FAI measures. Conclusion: The combined approach of adding vessel-specific FAI or lesion-specific FAI scores could improve the identification of ischemia compared with CCTA alone. The LAP volume was the independent risk factor for both tools.

Metabolomics of Arterial Stiffness

Arterial stiffness (AS) is one of the earliest detectable signs of structural and functional alterations of the vessel wall and an independent predictor of cardiovascular events and death. The emerging field of metabolomics can be utilized to detect a wide spectrum of intermediates and products of metabolism in body fluids that can be involved in the pathogenesis of AS. Research over the past decade has reinforced this idea by linking AS to circulating acylcarnitines, glycerophospholipids, sphingolipids, and amino acids, among other metabolite species. Some of these metabolites influence AS through traditional cardiovascular risk factors (e.g., high blood pressure, high blood cholesterol, diabetes, smoking), while others seem to act independently through both known and unknown pathophysiological mechanisms. We propose the term 'arteriometabolomics' to indicate the research that applies metabolomics methods to study AS. The 'arteriometabolomics' approach has the potential to allow more personalized cardiovascular risk stratification, disease monitoring, and treatment selection. One of its major goals is to uncover the causal metabolic pathways of AS. Such pathways could represent valuable treatment targets in vascular ageing.

Pericoronary fat attenuation index and coronary plaque quantified from coronary computed tomography angiography identify ischemia-causing lesions

BACKGROUND

The association between pericoronary fat attenuation index (FAI), plaque characteristics, and lesion-specific ischemia identified by fractional flow reserve (FFR) remains unclear.

METHODS

Coronary computed tomography angiography (CCTA) stenosis, FAI, plaque characteristics, FFR derived from computed tomography (FFR_CT) and FFR were assessed in 280 vessels of 247 patients. Stenosis ≥50% was considered obstructive. Optimal thresholds of FAI and plaque variables were defined by the area under the receiver-operating characteristics curve (AUC) analysis. Ischemia was defined by FFR ≤ 0.80.

RESULTS

FAI ≥ -71.9 HU, low-attenuation plaque (LAP) ≥ 49.62 mm³ and aggregate plaque volume (APV) ≥ 28.91% predicted ischemia independent of other plaque characteristics. The addition of FAI ≥ -71.9 HU improved discrimination (AUC, 0.720 vs. 0.674, P = 0.035) and reclassification abilities (category-free net reclassification index [NRI], 0.470, P < 0.001; relative integrated discrimination improvement [IDI], 0.047, P < 0.001) of ischemia compared with stenosis evaluation alone, with further discrimination (AUC, 0.772 vs. 0.720, P = 0.028) and reclassification abilities (NRI, 0.385, P = 0.001; relative IDI, 0.077, P < 0.001) of ischemia by adding information regarding LAP ≥49.62 mm³ + APV ≥ 28.91%. And the diagnostic performance of combination approach was comparable to that of FFR_CT alone (AUC, 0.772 vs. 0.762, P = 0.771).

CONCLUSIONS

Stenosis severity, FAI, plaque characteristics predicted lesion-specific ischemia. The combination of FAI and plaque assessment improved the discrimination of ischemia compared with stenosis assessment alone.

Impact of myocardial reperfusion on human plasma lipidome

The primary aim of the study is to investigate the temporal changes in plasma lipidome before and after reperfusion in patients with ST-segment elevation myocardial infarction (STEMI) and their association with myocardial injury. We found that 56% of the identified lipid species were significantly altered (corrected p< 0.05) in the first 24 h following reperfusion in patients with STEMI. Three lipid species, namely, acylcarnitine 18:2, TG 51:0, and LPC 17:1 were associated with a change in troponin concentration (delta troponin) and in-hospital cardiovascular events. Of these, acylcarnitine 18:2, and LPC 17:1 and their respective whole class levels, were significantly higher (p < 0.05) in the STEMI population than the age/sex-matched control subjects. Overall, our analyses showed a large shift in plasma lipidome in patients that undergo myocardial reperfusion. The differences found for acylcarnitines and LPC species and their association with both cardiac markers and cardiac outcomes need further validation.

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Human plasma lipidome rapidly shifts during myocardial reperfusion injury

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Novel plasma lipids are associated with cardiovascular events

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Acylcarnitines and lysoPCs correlate with the extent of myocardial injury

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Acute MI results in elevated plasma AC 18:2 and LPC 17:1 compared to controls

Biomarkers Utility: At the Borderline between Cardiology and Neurology

Biomarkers are important diagnostic and prognostic tools as they provide results in a short time while still being an inexpensive, reproducible and accessible method. Their well-known benefits have placed them at the forefront of research in recent years, with new and innovative discoveries being implemented. Cardiovascular and neurological diseases often share common risk factors and pathological pathways which may play an important role in the use and interpretation of biomarkers' values. Among the biomarkers used extensively in clinical practice in cardiology, hs-TroponinT, CK-MB and NTproBNP have been shown to be strongly influenced by multiple neurological conditions. Newer ones such as galectin-3, lysophosphatidylcholine, copeptin, sST2, S100B, myeloperoxidase and GDF-15 have been extensively studied in recent years as alternatives with an increased sensitivity for cardiovascular diseases, but also with significant results in the field of neurology. Thus, given their low specificity, the values interpretation must be correlated with the clinical judgment and other available investigations.

Metabolic Profiling and Metabolites Fingerprints in Human Hypertension: Discovery and Potential

Early detection of pathogenesis through biomarkers holds the key to controlling hypertension and preventing cardiovascular complications. Metabolomics profiling acts as a potent and high throughput tool offering new insights on disease pathogenesis and potential in the early diagnosis of clinical hypertension with a tremendous translational promise. This review summarizes the latest progress of metabolomics and metabolites fingerprints and mainly discusses the current trends in the application in clinical hypertension. We also discussed the associated mechanisms and pathways involved in hypertension's pathogenesis and explored related research challenges and future perspectives. The information will improve our understanding of the development of hypertension and inspire the clinical application of metabolomics in hypertension and its associated cardiovascular complications.

Ginsenosides regulation of lysophosphatidylcholine profiles underlies the mechanism of Shengmai Yin in attenuating atherosclerosis

ETHNOPHARMACOLOGICAL RELEVANCE

The traditional Chinese medicine (TCM) preparation, Shengmai Yin (SMY), is widely applied in cardiovascular disease treatments. However, the pharmacological mechanism of its therapeutic effects has not been fully clarified.

AIM OF THIS STUDY

This study aimed to clearly define the efficacy and underlying mechanism of SMY and its active components in protecting against atherosclerosis.

MATERIALS AND METHODS

The pharmacological effects of SMY and its components were evaluated upon a mouse hypercholesteremia model induced by a high cholesterol diet (HCD) for 12 weeks and Apoe^-/- mice, a mouse atherosclerosis model. Pathological indicators including serum cholesterol levels, cytokines and histological changes in aortic root plaques were assessed. Untargeted metabolomic, untargeted lipidomic and targeted lipidomic changing profiles were investigated to clarify pharmacological mechanisms.

RESULTS

SMY and red ginseng crude extracts (GE) significantly decreased the serum cholesterol levels in hypercholesteremia mice and reduced the aortic root plaque areas and exerted antiatherogenic efficacy in Apoe^-/- mice. Moreover, total red ginseng saponin extracts (TGS) showed the most apparent improvement on maintaining lipid homeostasis, representing the effects of red ginseng in SMY on atherosclerosis treatment. Mechanically, TGS inhibited serum secreted phospholipase A₂ (sPLA₂) activity and lowered the serum levels of lysophosphatidylcholine (lysoPC), which is a risk factor for atherosclerosis.

CONCLUSIONS

Our findings revealed that ginsenosides from SMY exerted therapeutic effects on atherosclerosis by maintaining lipid homeostasis including cholesterol and lysoPCs.

Analysis of Metabolic Markers in Patients with Chronic Heart Failure before and after LVAD Implantation

Chronic heart failure (HF) is a clinical syndrome characterized by functional impairments of the myocardium. Metabolic and clinical changes develop with disease progression. In an advanced state, left ventricular assist devices (LVADs) are implanted for mechanical unloading. Our study aimed to assess the effects of LVAD implantation on the metabolic phenotypes and their potential to reverse the latter in patients with advanced HF. Plasma metabolites were analyzed by LC–MS/MS in 20 patients with ischemic cardiomyopathy (ICM), 20 patients with dilative cardiomyopathy (DCM), and 20 healthy controls. Samples were collected in HF patients before, 30 days after, and >100 days after LVAD implantation. Out of 188 measured metabolites, 63 were altered in HF. Only three metabolites returned to pre-LVAD concentrations 100 days after LVAD implantation. Pre-LVAD differences between DCM and ICM were mainly observed for amino acids and biogenic amines. This study shows a reversal of metabolite abnormalities in HF as a result of LVAD implantation. The etiology of the underlying disease plays an essential role in defining which specific metabolic parameter is altered in HF and reversed by LVAD implantation. Our findings provide a detailed insight into the disease pattern of ICM and DCM and the potential for reversibility of metabolic abnormalities in HF.

The effect of hepatitis C virologic clearance on cardiovascular disease biomarker lipoprotein-associated phospholipase A2 and its relation to serum lipids

Background

Chronic hepatitis C virus (HCV) infection has been linked to cardiovascular disease (CVD). However, CVD risk prediction in chronic HCV-infected patients is problematic as the prevalence of different cardiac biomarkers in these patients is currently unknown. Serum lipids, which are routinely used in traditional CVD risk scores, may underestimate CVD risk in these patients, while non-hepatically produced biomarkers, including lipoprotein-associated phospholipase A2 (Lp-PLA2), may better reflect CVD risk. In this study, we aimed to evaluate the effect of sustained virologic response (SVR) on CVD risk, predicted by Lp-PLA2 mass in comparison with serum lipid levels.

Results

Ninety chronic HCV-infected patients were enrolled in this study. Serum Lp-PLA2 mass was measured before and after HCV treatment via direct-acting antivirals and compared with the changes in serum lipids and Framingham risk score (FRS). The Lp-PLA2 level was categorized into high (>235 ng/ml) or low predicted CVD risk (≤235 ng/ml). Mean Lp-PLA2 mass significantly decreased from 322.37 ± 79.15 ng/ml to 263.79 ± 51.804 ng/ml with SVR, and the number of high-risk patients significantly dropped from 82.22 to 60% after treatment. Total cholesterol, low-density lipoprotein, and high-density lipoprotein levels were low/optimal at baseline (170 ± 40.34 mg/dl, 71.98 ± 24.12 mg/dl, and 48.43 ± 6.79 mg/dl) and significantly increased with SVR (195.66 ± 55.68 mg/dl, 103.24 ± 46.57 mg/dl, and 53.91 ± 8.67 mg/dl). According to FRS, only 30% of patients were moderate/high risk at baseline and insignificantly declined to 28.89% post-treatment.

Conclusion

Lp-PLA2 may be a better predictor of CVD risk in chronic HCV-infected patients. Furthermore, SVR may reduce hepatic inflammation and consequently CVD risk.

Prognostic value of pericoronary inflammation and unsupervised machine-learning-defined phenotypic clustering of CT angiographic findings

BACKGROUND

Pericoronary adipose tissue attenuation expressed by fat attenuation index (FAI) on coronary CT angiography (CCTA) reflects pericoronary inflammation and is associated with cardiac mortality.

OBJECTIVE

The aim of this study was to define the sub-phenotypes of coronary CCTA-defined plaque and whole vessel quantification by unsupervised machine learning (ML) and its prognostic impact when combined with pericoronary inflammation.

METHODS

A total of 220 left anterior descending arteries (LAD) with intermediate stenosis who underwent fractional flow reserve (FFR) measurement and CCTA were studied. After removal of outcome and FAI data, the phenotype heterogeneity of CCTA-defined plaque and whole vessel quantification was investigated by unsupervised hierarchical clustering analysis based on Ward's method. Detailed features of CCTA findings were assessed according to the clusters (CS1 and CS2). Major adverse cardiac events (MACE)-free survivals were assessed according to the stratifications by FAI and the clusters.

RESULTS

Compared with CS2 (n = 119), CS1 (n = 101) were characterized by greater vessel size, increased plaque volume, and high-risk plaque features. FAI was significantly higher in CS1. ROC analyses revealed that best cut-off value of FAI to predict MACE was -73.1. Kaplan-Meier analysis revealed that lesions with FAI ≥ -73.1 had a significantly higher risk of MACE. Multivariate Cox proportional hazards regression analysis revealed that age, FAI ≥ -73.1, and the clusters were independent predictors of MACE.

CONCLUSION

Unsupervised hierarchical clustering analysis revealed two distinct CCTA-defined subgroups and discriminated by high-risk plaque features and increased FAI. The risk of MACE differs significantly according to the increased FAI and ML-defined clusters.

The "Hitchhiker's Guide to the Galaxy" of Endothelial Dysfunction Markers in Human Fertility

Endothelial dysfunction is an early event in the pathogenesis of atherosclerosis and represents the first step in the pathogenesis of cardiovascular diseases. The evaluation of endothelial health is fundamental in clinical practice and several direct and indirect markers have been suggested so far to identify any alterations in endothelial homeostasis. Alongside the known endothelial role on vascular health, several pieces of evidence have demonstrated that proper endothelial functioning plays a key role in human fertility and reproduction. Therefore, this state-of-the-art review updates the endothelial health markers discriminating between those available for clinical practice or for research purposes and their application in human fertility. Moreover, new molecules potentially helpful to clarify the link between endothelial and reproductive health are evaluated herein.

Lipoprotein-associated phospholipase A2 levels, endothelial dysfunction and arterial stiffness in patients with stable coronary artery disease

BACKGROUND

Lipoprotein-associated Phospholipase A2 (Lp-PLA2), can exert proinflammatory as well as proatherogenic properties on the vascular wall. The current study sought to evaluate the influence of high Lp-PLA2 levels on indices of arterial wall properties in patients with stable coronary artery disease (CAD).

METHODS

Three hundred seventy-four consecutive patients with stable CAD (mean age 61 ± 11 years, 89% males) were enrolled in this single-center cross-sectional study. Flow-mediated dilation (FMD) was used to assess endothelial function and augmentation index (AIx) of the central aortic pressure was used to assess reflected waves. ELISA was used to determine Lp-PLA2 serum levels.

RESULTS

After dividing the participants in 3 equal groups based on the tertiles of circulating Lp-PLA2 values, no significant differences were demonstrated between those in the 3rd tertile with Lp-PLA2 values > 138 μg/L, in the 2nd tertile with Lp-PLA2 values between 101 and 138 μg/L and in the 1st tertile (Lp-PLA2 values < 101 μg/L) regarding age, male gender, smoking habits, family history of CAD or history of a previous myocardial infarction, diabetes mellitus, arterial hypertension, hyperlipidemia, duration of CAD and treatment with relevant medication. Importantly, subjects with Lp-PLA2 values in the highest tertile, had significantly reduced FMD values compared to the middle and lower tertile (4.43 ± 2.37% vs. 4.61 ± 1.97% vs. 5.20 ± 2.52% respectively, P = 0.03). Patients in the highest tertile of Lp-PLA2 values had significantly higher AIx values (24.65 ± 8.69% vs. 23.33 ± 9.65%, P = 0.03), in comparison to the lowest tertile, with Lp-PLA2 values < 101 μg/L. A linear regression analysis showed that Lp-PLA2 values > 138 μg/L negatively correlated to FMD [b = - 0.45 (95% CI: - 0.79 - -0.11), P = 0.01] and AIx values [b = 1.81 (95% CI: 0.57-3.05), P < 0.001] independently of cofounders like gender, age, diabetes mellitus, arterial hypertension, dyslipidemia, smoking habits, family history of CAD, history of previous myocardial infarction, serum glucose, circulating lipid levels, duration of CAD, antihypertensive medication, antidiabetic drugs, statin therapy and treatment with β-blockers.

CONCLUSIONS

Elevated Lp-PLA2 levels relate to endothelial dysfunction and arterial stiffness in patients with stable CAD independently from classical risk factors for CAD, statin use, antihypertensive treatment, and duration of the disease.

Metabolomic analysis coupled with extreme phenotype sampling identified that lysophosphatidylcholines are associated with multisite musculoskeletal pain

ABSTRACT

Musculoskeletal pain often occurs simultaneously at multiple anatomical sites. The aim of the study was to identify metabolic biomarkers for multisite musculoskeletal pain (MSMP) by metabolomics with an extreme phenotype sampling strategy. The study participants (n = 610) were derived from the Newfoundland Osteoarthritis Study. Musculoskeletal pain was assessed using a self-reported pain questionnaire where painful sites were circled on a manikin by participants and the total number of painful sites were calculated. Targeted metabolomic profiling on fasting plasma samples was performed using the Biocrates AbsoluteIDQ p180 kit. Plasma cytokine concentrations including tumor necrosis factor-α, interleukin-6, interleukin-1β, and macrophage migration inhibitory factor were assessed by enzyme-linked immunosorbent assay. Data on blood cholesterol profiles were retrieved from participants' medical records. Demographic, anthropological, and clinical information was self-reported. The number of reported painful sites ranged between 0 and 21. Two hundred and five participants were included in the analysis comprising 83 who had ≥7 painful sites and 122 who had ≤1 painful site. Women and younger people were more likely to have MSMP (P ≤ 0.02). Multisite musculoskeletal pain was associated with a higher risk of having incontinence, worse functional status and longer period of pain, and higher levels of low-density lipoprotein and non-high-density lipoprotein cholesterol (all P ≤ 0.03). Among the 186 metabolites measured, 2 lysophosphatidylcholines, 1 with 26 carbons with no double bond and 1 with 28 carbons with 1 double bond, were significantly and positively associated with MSMP after adjusting for multiple testing with the Bonferroni method (P ≤ 0.0001) and could be considered as novel metabolic markers for MSMP.

Inflammation and cardiovascular diseases: lessons from seminal clinical trials

Inflammation has been long regarded as a key contributor to atherosclerosis. Inflammatory cells and soluble mediators play critical roles throughout arterial plaque development and accordingly, targeting inflammatory pathways effectively reduces atherosclerotic burden in animal models of cardiovascular (CV) diseases. Yet, clinical translation often led to inconclusive or even contradictory results. The Canakinumab Anti-inflammatory Thrombosis Outcome Study (CANTOS) followed by the Colchicine Cardiovascular Outcomes Trial (COLCOT) were the first two randomized clinical trials to convincingly demonstrate the effectiveness of specific anti-inflammatory treatments in the field of CV prevention, while other phase III trials-including the Cardiovascular Inflammation Reduction Trial one using methotrexate-were futile. This manuscript reviews the main characteristics and findings of recent anti-inflammatory Phase III trials in cardiology and discusses their similarities and differences in order to get further insights into the contribution of specific inflammatory pathways on CV outcomes. CANTOS and COLCOT demonstrated efficacy of two anti-inflammatory drugs (canakinumab and colchicine, respectively) in the secondary prevention of major adverse CV events (MACE) thus providing the first confirmation of the involvement of a specific inflammatory pathway in human atherosclerotic CV disease (ASCVD). Also, they highlighted the NOD-, LRR-, and pyrin domain-containing protein 3 inflammasome-related pathway as an effective therapeutic target to blunt ASCVD. In contrast, other trials interfering with a number of inflammasome-independent pathways failed to provide benefit. Lastly, all anti-inflammatory trials underscored the importance of balancing the risk of impaired host defence with an increase in infections and the prevention of MACE in CV patients with residual inflammatory risk.

cGMP Signaling in Cardiovascular Diseases: Linking Genotype and Phenotype

Cyclic guanosine 3',5'-monophosphate (cGMP) is the key second messenger molecule in nitric oxide signaling. Its rapid generation and fate, but also its role in mediating acute cellular functions has been extensively studied. In the past years, genetic studies suggested an important role for cGMP in affecting the risk of chronic cardiovascular diseases, for example, coronary artery disease and myocardial infarction. Here, we review the role of cGMP in atherosclerosis and other cardiovascular diseases and discuss recent genetic findings and identified mechanisms. Finally, we highlight open questions and promising research topics.

On the present and future role of Lp-PLA2 in atherosclerosis-related cardiovascular risk prediction and management

Circulating concentration and activity of secretory phospholipase A₂ (sPLA₂) and lipoprotein-associated phospholipase A₂ (Lp-PLA₂) have been proven as biomarkers of increased risk of atherosclerosis-related cardiovascular disease (ASCVD). Lp-PLA₂ might be part of the atherosclerotic process and may contribute to plaque destabilisation through inflammatory activity within atherosclerotic lesions. However, all attempts to translate the inhibition of phospholipase into clinically beneficial ASCVD risk reduction, including in randomised studies, by either non-specific inhibition of sPLA₂ (by varespladib) or specific Lp-PLA₂ inhibition by darapladib, unexpectedly failed. This gives us a strong imperative to continue research aimed at a better understanding of how Lp-PLA₂ and sPLA₂ regulate vascular inflammation and atherosclerotic plaque development. From the clinical viewpoint there is a need to establish and validate the existing and emerging novel anti-inflammatory therapeutic strategies to fight against ASCVD development, by using potentially better animal models and differently designed clinical trials in humans.

Expression of Hypoxia-Inducible Factor-1α (HIF1A) and Lp-PLA2 in Low, Intermediate, and High Cardiovascular Disease Risk Population

BACKGROUND

The pathomechanism of CVD is a complex and multifactorial process. The primary mechanism of CVD is atherosclerosis. Inflammation in atherogenesis raises the risk of hypoxia, which will activate hypoxia-inducible factor-1α (HIF1A). Also, together with lipoprotein-associated phospholipase A2 (Lp-PLA2), an inflammatory mediator for atherogenesis.

PURPOSE

This study aims to measure the hypoxia-inducible factor-1α (HIF1A) expression and its correlation to Lp-PLA2 expression at low-risk, intermediate, and high-risk CVD populations.

PATIENTS AND METHODS

The study used a correlational analysis method with a total sampling technique in 160 individuals in the risk population. The atherosclerosis risk group was analyzed using the Framingham Risk Score and categorized into low, intermediate, and high-risk groups. Venous blood samples taken from respondents were measured using the ELISA method with Lp-PLA2 and HIF-1α as parameters. Data were analyzed using normality test, homogeneity test, one-way ANOVA, post hoc-Tukey HSD, and Pearson correlation.

RESULTS

The concentration of HIF1A had a very strong correlation with Lp-PLA2 expression, both in the low-risk group (r = 0.512), intermediate (r = 0.512), and high (r = 0.715) (P <0.05). However, the concentrations of Lp-PLA2 did not match the FRS.

CONCLUSION

HIF1A expression increased with increasing risk, while Lp-PLA2 expression decreased with increasing risk of atherosclerosis based on the FRS category. There is a significant correlation between HIF1A expression and Lp-PLA2 expression based on FRS.

Interface of Phospholipase Activity, Immune Cell Function, and Atherosclerosis

Phospholipases are a family of lipid-altering enzymes that can either reduce or increase bioactive lipid levels. Bioactive lipids elicit signaling responses, activate transcription factors, promote G-coupled-protein activity, and modulate membrane fluidity, which mediates cellular function. Phospholipases and the bioactive lipids they produce are important regulators of immune cell activity, dictating both pro-inflammatory and pro-resolving activity. During atherosclerosis, pro-inflammatory and pro-resolving activities govern atherosclerosis progression and regression, respectively. This review will look at the interface of phospholipase activity, immune cell function, and atherosclerosis.

Identification and visualization of oxidized lipids in atherosclerotic plaques by microscopic imaging mass spectrometry-based metabolomics

BACKGROUND AND AIMS

Dysregulated lipid metabolism has emerged as one of the major risk factors of atherosclerosis. Presently, there is a consensus that oxidized LDL (oxLDL) promotes development of atherosclerosis and downstream chronic inflammatory responses. Due to the dynamic metabolic disposition of lipoprotein, conventional approach to purify bioactive lipids for subsequent comprehensive analysis has proven to be inadequate for elucidation of the oxidized lipids species accountable for pathophysiology of atherosclerotic lesions. Herein, we aimed to utilize a novel mass microscopic imaging technology, coupled with mass spectrometry (MS) to characterize oxidized lipids in atherosclerotic lesions.

METHODS

We attempted to use MALDI-TOF-MS and iMScope to identify selected oxidized lipid targets and visualize their respective localizations in study models of atherosclerosis.

RESULTS

Based on the MS analysis, detection of 7-K under positive ionization through product ion peak at m/z 383 [M + H-H₂O] indicated the distinctive presence of targeted lipid within Cu²⁺-oxLDL and Cu²⁺-oxLDL loaded macrophage-like J774A.1 cells, along with other cholesterol oxidation products. Moreover, the application of two-dimensional iMScope has successfully visualized the localization of lipids in aortic atherosclerotic plaques of the Watanabe heritable hyperlipidemic (WHHL) rabbit. Distinctive lipid distribution profiles were observed in atherosclerotic lesions of different sizes, especially the localizations of lysoPCs in atherosclerotic plaques.

CONCLUSIONS

Taken together, we believe that both MALDI-TOF-MS and iMScope metabolomics technology may offer a novel proposition for future pathophysiological studies of lipid metabolism in atherosclerosis.

Prognostic value of CHADS2 and CHA2DS2-VASc scores for post-discharge outcomes in patients with acute coronary syndrome undergoing percutaneous coronary intervention

The CHADS2 and CHA2DS2-VASc scores were initially developed to assess the risk of stroke or systemic embolism in patients with atrial fibrillation (AF). Recently, these two scoring systems have been demonstrated to predict long- and short-term cardiovascular (CV) outcomes in many patient cohorts. However, to the best of our knowledge, their prognostic value has not been fully elucidated in patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI). This study aimed to investigate the association of CHADS2 and CHA2DS2-VASc scores with CV outcomes in such patients.We included a total of 915 ACS patients undergoing PCI in this study. CHADS2 and CHA2DS2-VASc scores were calculated from data collected before discharge. The primary endpoint was defined as a composite of major adverse CV events (MACE) including overall death, nonfatal stroke, nonfatal myocardial infarction (MI) and unplanned repeat revascularization. We assessed MACE's relationship to CHADS2 and CHA2DS2-VASc scores using Cox proportional-hazard regression analyses.Mean follow-up duration was 918 days. MACE occurred in 167 (18.3%) patients. A higher CHADS2 score was associated with reduced event-free survival (EFS) from MACE (logrank test, P = .007) with differences potentiated if stratified by CHA2DS2-VASc score (logrank test, P < .001). Univariate analysis showed that both CHADS2 and CHA2DS2-VASc scores were good predictors of MACE. In the multivariate Cox proportional-hazard regression analysis, CHA2DS2-VASc score (hazard ratio [HR], 1.15; 95% confidence interval [CI] 1.04-1.27; P = .007) remained a useful predictor of MACE; however, CHADS2 score was no longer associated with increased risk of MACE. C-statistics for CHA2DS2-VASc score, GRACE (Global Registry of Acute Coronary Events) hospital discharge risk score (GRACE Score) and SYNTAX (Synergy between PCI with TAXUS and Cardiac Surgery) Score II (SS II) in predicting MACE were 0.614, 0.598, and 0.609, respectively.CHA2DS2-VASc score was an independent and significant predictor of MACE in ACS patients undergoing PCI, and its discriminatory performance was not inferior to those of GRACE Score and SS II.

The relationship of lipoprotein-associated phospholipase A2 activity with the seriousness of coronary artery disease

BACKGROUND

The level of lipoprotein-associated phospholipase A2 (LP-PLA2) in serum is independently correlated to coronary artery diseases (CAD). The aim of the study was to determine whether LP-PLA2 activity is positively associated with the seriousness of CAD.

METHODS

Amount to 1056 patients suspected of having CAD underwent coronary angiography (CAG) to determine the seriousness of CAD. According to the amount of diseased coronary branches, the 1056 patients were split into three groups: single-vessel stenosis group, multiple-vessels stenosis group (> or = 2 diseased coronary branches),and control group (no diseased coronary branches). According to CAG results, electrocardiography, cardiac biomarker, and clinical presentation, all patients were split into four groups: acute myocardial infarction (AMI), unstable angina (UA), stable angina (SA), and control groups (excluding CAD). The activity of LP-PLA2 was compared statistically among the subgroups. Receiver operating characteristic analysis was applied to investigate the role of LP-PLA2 in evaluating the presence and seriousness of CAD.

RESULTS

The level of LP-PLA2 increased in line with the number of diseased coronary branches. The levels of LP-PLA2 in the AMI and UA groups were observably higher when compared with the control and SA groups. LP-PLA2 had 75.6% sensitivity and 67.3% specificity for recognizing CAD, and 53.0% sensitivity and 80.3% specificity for recognizing severe coronary artery lesions.

CONCLUSION

The activity of LP-PLA2 is positively correlated to the seriousness of CAD.

Role of Low-Density Lipoprotein in Early Vascular Aging Associated With Systemic Lupus Erythematosus

OBJECTIVE

Patients with systemic lupus erythematosus (SLE) often have atherosclerotic complications at a young age but normal low-density lipoprotein (LDL) levels. This study was undertaken to investigate the role of LDL composition in promoting early vascular aging in SLE patients.

METHODS

Plasma LDL from 45 SLE patients (SLE-LDL) and from 37 normal healthy controls (N-LDL) was chromatographically divided into 5 subfractions (L1-L5), and the subfraction composition was analyzed. Correlations between subfraction levels and signs of early vascular aging were assessed. Mechanisms of lipid-mediated endothelial dysfunction were explored using in vitro assays and experiments in apoE^-/- mice.

RESULTS

The L5 percentage was increased 3.4 times in the plasma of SLE patients compared with normal controls. This increased percentage of SLE-L5 was positively correlated with the mean blood pressure (r = 0.27, P = 0.04), carotid intima-media thickness (IMT) (right carotid IMT, r = 0.4, P = 0.004; left carotid IMT, r = 0.36, P = 0.01), pulse wave velocity (r = 0.29, P = 0.04), and blood levels of CD16+ monocytes (r = 0.35, P = 0.004) and CX3CL1 cytokines (r = 0.43, P < 0.001) in SLE patients. Matrix-assisted laser desorption ionization-time-of-flight mass spectrometry analysis revealed that plasma levels of lysophosphatidylcholine (LPC) and platelet-activating factor (PAF) were increased in SLE-LDL and in the SLE-L5 plasma subfraction. Injecting SLE-LDL, SLE-L5, or LPC into young, male apoE^-/- mice caused increases in plasma CX3CL1 levels, aortic fatty-streak areas, aortic vascular aging, and macrophage infiltration into the aortic wall, whereas injection of N-LDL or SLE-L1 had negligible effects (n = 3-8 mice per group). In vitro, SLE-L5 lipid extracts induced increases in CX3CR1 and CD16 expression in human monocytes; synthetic PAF and LPC had similar effects. Furthermore, lipid extracts of SLE-LDL and SLE-L5 induced the expression of CX3CL1 and enhanced monocyte-endothelial cell adhesion in assays with bovine aortic endothelial cells.

CONCLUSION

An increase in plasma L5 levels, not total LDL concentration, may promote early vascular aging in SLE patients, leading to premature atherosclerosis.

Assessment of peripheral endothelial function predicts future risk of solid-tumor cancer

AIMS

Cardiovascular health metrics predict the risk not only of cardiovascular diseases but also of several types of cancers. Microvascular endothelial dysfunction can predict future cardiovascular adverse events, but the predictive value of microvascular endothelial dysfunction for future risk of solid-tumor cancer has not been characterized.

METHODS

A total of 488 patients who underwent microvascular endothelial function assessment using reactive hyperemia peripheral arterial tonometry were included in this study. Microvascular endothelial dysfunction was defined as a reactive hyperemia peripheral arterial tonometry index ≤2.0.

RESULTS

Of 221 patients with a baseline reactive hyperemia peripheral arterial tonometry index ≤2.0, 21 patients (9.5%) were diagnosed with incident solid-tumor cancer during follow-up, whereas of 267 patients with a baseline reactive hyperemia peripheral arterial tonometry index >2.0, 10 patients (3.7%) were diagnosed with incident solid-tumor cancer during follow-up (p = 0.009). Patients with a reactive hyperemia peripheral arterial tonometry index ≤2.0 had lower solid-tumor cancer-free survival compared to patients with a reactive hyperemia peripheral arterial tonometry index >2.0 (log-rank p = 0.017) (median follow-up 6.0 (3.0-9.1) years). Cox proportional hazard analyses showed that a reactive hyperemia peripheral arterial tonometry index ≤2.0 predicted the incidence of solid-tumor cancer, with a hazard ratio of 2.52 (95% confidence interval 1.17-5.45; p = 0.019) after adjusting for age, sex, and coronary artery disease, 2.83 (95% confidence interval 1.30-6.17; p = 0.009) after adjusting for diabetes mellitus, hypertension, smoking status, and body mass index >30 kg/m2, 2.79 (95% confidence interval 1.21-6.41; p = 0.016) after adjusting for fasting plasma glucose, systolic blood pressure, smoking status (current or former), and body mass index, and 2.43 (95% confidence interval 1.10-5.34; p = 0.028) after adjusting for Framingham risk score.

CONCLUSION

Microvascular endothelial dysfunction, as defined by a reactive hyperemia peripheral arterial tonometry index ≤2.0, was associated with a greater than two-fold increased risk of solid-tumor cancer. Microvascular endothelial dysfunction may be a useful marker to predict the future risk of solid-tumor cancer, in addition to its known ability to predict cardiovascular disease. Further research is necessary to develop adequate cancer screening strategies for patients with microvascular endothelial dysfunction.

Metabolomic Signature of Early Vascular Aging (EVA) in Hypertension

Arterial stiffening is a hallmark of early vascular aging (EVA) syndrome and an independent predictor of cardiovascular morbidity and mortality. In this case-control study we sought to identify plasma metabolites associated with EVA syndrome in the setting of hypertension. An untargeted metabolomic approach was used to identify plasma metabolites in an age-, BMI-, and sex-matched groups of EVA (n = 79) and non-EVA (n = 73) individuals with hypertension. After raw data processing and filtration, 497 putative compounds were characterized, out of which 4 were identified as lysophosphaditylcholines (LPCs) [LPC (18:2), LPC (16:0), LPC (18:0), and LPC (18:1)]. A main finding of this study shows that identified LPCs were independently associated with EVA status. Although LPCs have been shown previously to be positively associated with inflammation and atherosclerosis, we observed that hypertensive individuals characterized by 4 down-regulated LPCs had 3.8 times higher risk of EVA compared to those with higher LPC levels (OR = 3.8, 95% CI 1.7–8.5, P < 0.001). Our results provide new insights into a metabolomic phenotype of vascular aging and warrants further investigation of negative association of LPCs with EVA status. This study suggests that LPCs are potential candidates to be considered for further evaluation and validation as predictors of EVA in patients with hypertension.

Predictive performance of aortic arch calcification for clinical outcomes in patients with acute coronary syndrome that undergo percutaneous coronary intervention: A prospective clinical study

Currently, little is known regarding the predictive utility of aortic arch calcification (AAC) for clinical outcomes in patients with acute coronary syndrome (ACS) who undergo percutaneous coronary intervention (PCI). The present study was designed to investigate the predictive performance of AAC as detected by chest x-ray for clinical outcomes among ACS patients undergoing PCI.A total of 912 patients who were diagnosed as ACS and treated with PCI were included in this prospective, cohort study. All study participants received chest x-rays on admission, and a semiquantitative 4-point scale was used to assess the extent of AAC. The primary end point was defined as a composite of major adverse cardiovascular events (MACE) comprising death, nonfatal stroke, nonfatal myocardial infarction, and unplanned repeat revascularization. The key secondary end point was the composite of cardiovascular death, nonfatal stroke, and nonfatal myocardial infarction. The prognostic values of AAC were assessed in multivariate Cox-proportional hazards regression analyses adjusted for major confounders.The mean follow-up duration was 917 days and, during the follow-up period, MACE occurred in 168 (18.4%) patients. Kaplan-Meier analyses revealed significantly higher incidences of the primary and key secondary end points in patients with higher AAC grades (log-rank test; all P < .001). Multivariate Cox-proportional hazards regression analyses showed that, in comparison to AAC grade 0, the hazard ratios of AAC grades 1, 2, and 3 for predicting MACE were 1.63 (95% confidence interval [CI] 0.99-2.67), 2.15 (95% CI 1.27-3.62), and 2.88 (95% CI 1.41-5.86), respectively. The C-index of the variables, including peripheral arterial disease and serum levels of triglyceride for predicting MACE, was 0.644 (95% CI 0.600-0.687) versus 0.677 (95% CI 0.635-0.719) when AAC grades were also included; the continuous net reclassification improvement was 16.5% (8.7%-23.4%; P < .001).The extent of AAC as detected by chest x-ray is an independent predictor of MACE among ACS patients undergoing PCI. Further research is warranted to evaluate whether specific treatment strategies that are established based on AAC extent are needed for optimal risk reduction in relevant patient populations.

Diagnostic performance of perivascular fat attenuation index to predict hemodynamic significance of coronary stenosis: a preliminary coronary computed tomography angiography study

OBJECTIVE

This study aimed to investigate the association between perivascular fat attenuation index (FAI) and hemodynamic significance of coronary lesions.

METHODS

Patients with stable angina who underwent coronary computed tomography (CT) angiography and invasive fractional flow reserve (FFR) measurement within 2 weeks were retrospectively included. Lesion-based perivascular FAI, high-risk plaque features, total plaque volume (TPV), machine learning-based FFR_CT, and other parameters were recorded. Lesions with invasive FFR ≤ 0.8 were considered functionally significant.

RESULTS

This study included 167 patients with 219 lesions. Diameter stenosis (DS), lesion length, TPV, and perivascular FAI were significantly larger or longer in the group of hemodynamically significant lesions (FFR ≤ 0.8). In addition, smaller FFR_CT value was associated with functionally significant lesions (0.720 ± 0.11 vs 0.846 ± 0.10, p < 0.001). No significant difference was found between the hemodynamically significant and insignificant subgroups with respect to CT-derived high-risk plaque features. According to multivariate analysis, DS, TPV, and perivascular FAI were significant predictors of lesion-specific ischemia. When integrating DS, TPV, and perivascular FAI, the area under the curve (AUC) of this combined method was 0.821, which was similar to that of FFR_CT (AUC, 0.821 vs 0.850; p = 0.426). The diagnostic accuracy of FFR_CT was higher than that of the combined approach, but the difference was statistically insignificant (79.0% vs 74.0%, p = 0.093).

CONCLUSIONS

Perivascular FAI was significantly higher for flow-limiting lesions than for non-flow-limiting lesions. The combined use of FAI, TPV, and DS could predict ischemic coronary stenosis with high diagnostic accuracy.

KEY POINTS

• Perivascular FAI was significantly higher for flow-limiting lesions than for non-flow-limiting lesions. • Combined use of FAI, plaque volume, and DS provided diagnostic performance comparable to that of machine learning-based FFR _CTfor predicting ischemic coronary stenosis. • No significant difference was found between the hemodynamically significant and insignificant subgroups with respect to CT-derived high-risk plaque features.

Performance Characteristics and Clinical Value of the Lipoprotein-Associated Phospholipase A2 by an Enzymatic Kinetic Method

OBJECTIVE

To analyze the performance characteristics, stability, and clinical value of lipoprotein-associated phospholipase A2 (Lp-PLA2) using an enzymatic kinetic method.

METHODS

The performance characteristics included reference intervals, precision, and accuracy. We assessed Lp-PLA2 stability by comparing Lp-PLA2 changes under different conditions. Lp-PLA2 was determined in the following groups: control individuals, patients with coronary heart disease (CHD), patients of different lipid subgroups within CHD, and patients with high total cholesterol (TC). Also, correlations between Lp-PLA2 and traditional cardiovascular risk factors were assessed.

RESULTS

The mean (SD) reference interval of serum Lp-PLA2 activity was 451 (113) U per L with sex differences. Inter- and intra-assay precision revealed coefficients of variance (CVs) of 1.81% to 2.63% and 1.43% to 1.77%. The average bias was 0.33%. Lp-PLA2 activity was stable. In the CHD group, high-lipid subgroups, and high-TC group, Lp-PLA2 was elevated, and correlation was observed between Lp-PLA2 and traditional risk factors.

CONCLUSION

Lp-PLA2 activity has important clinical value in CHD.

Diagnostic and prognostic significance of mRNA expressions of apolipoprotein A and C family genes in hepatitis B virus-related hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is among the most common and lethal malignancies worldwide. Apolipoproteins (APOs) have been reported increasingly for their relationships with tumors. We aim at exploring the potential relationships of apolipoprotein A (APOA) and apolipoprotein C (APOC) family members with HCC.

METHODS

A data set, containing 212 hepatitis B virus-related HCC patients, was used for analysis. The diagnostic and prognostic ability of APOA and APOC family genes was figured out. Risk score models and nomograms were developed for the HCC prognosis prediction. Moreover, molecular mechanism exploration were identified biological processes and metabolic pathways of these genes involved in. Validation analysis was carried out using online website.

RESULTS

APOA1, APOC1, APOC3, and APOC4 showed robust diagnosis significance (all P < 0.05). APOA4, APOC3, and APOC4 were associated with the overall survival (OS) while APOA4 and APOC4 were linked to recurrence-free survival (RFS, all P ≤ 0.05). Risk score models and nomograms had the advantage of predicting OS and RFS for HCC. Molecular mechanism exploration indicated that these genes were involved in the steroid metabolic process, the PPAR signaling pathway, and fatty acid metabolism. Besides that, validation analysis revealed that APOC1 and APOC4 had an association with OS; and APOC3 was associated with OS and RFS (all P ≤ 0.05).

CONCLUSIONS

APOA1, APOC1, APOC3, and APOC4 are likely to be potential diagnostic biomarkers and APOC3 and APOC4 are likely to be potential prognostic biomarkers for hepatitis B virus-related HCC. They may be involved in the steroid metabolic process, PPAR signaling pathway, and fatty acid metabolism.

Small-molecule inhibitors as potential therapeutics and as tools to understand the role of phospholipases A2

Phospholipase A2 (PLA2) enzymes are involved in various inflammatory pathological conditions including arthritis, cardiovascular and autoimmune diseases. The regulation of their catalytic activity is of high importance and a great effort has been devoted in developing synthetic inhibitors. We summarize the most important small-molecule synthetic PLA2 inhibitors developed to target each one of the four major types of human PLA2 (cytosolic cPLA2, calcium-independent iPLA2, secreted sPLA2, and lipoprotein-associated LpPLA2). We discuss recent applications of inhibitors to understand the role of each PLA2 type and their therapeutic potential. Potent and selective PLA2 inhibitors have been developed. Although some of them have been evaluated in clinical trials, none reached the market yet. Apart from their importance as potential medicinal agents, PLA2 inhibitors are excellent tools to unveil the role that each PLA2 type plays in cells and in vivo. Modern medicinal chemistry approaches are expected to generate improved PLA2 inhibitors as new agents to treat inflammatory diseases.

Automated plaque analysis for the prognostication of major adverse cardiac events

OBJECTIVE

The purpose of this study is to assess the value of an automated model-based plaque characterization tool for the prediction of major adverse cardiac events (MACE).

METHODS

We retrospectively included 45 patients with suspected coronary artery disease of which 16 (33%) experienced MACE within 12 months. Commercially available plaque quantification software was used to automatically extract quantitative plaque morphology: lumen area, wall area, stenosis percentage, wall thickness, plaque burden, remodeling ratio, calcified area, lipid rich necrotic core (LRNC) area and matrix area. The measurements were performed at all cross sections, spaced at 0.5 mm, based on fully 3D segmentations of lumen, wall, and each tissue type. Discriminatory power of these markers and traditional risk factors for predicting MACE were assessed.

RESULTS

Regression analysis using clinical risk factors only resulted in a prognostic accuracy of 63% with a corresponding area under the curve (AUC) of 0.587. Based on our plaque morphology analysis, minimal cap thickness, lesion length, LRNC volume, maximal wall area/thickness, the remodeling ratio, and the calcium volume were included into our prognostic model as parameters. The use of morphologic features alone resulted in an increased accuracy of 77% with an AUC of 0.94. Combining both clinical risk factors and morphological features in a multivariate logistic regression analysis increased the accuracy to 87% with a similar AUC of 0.924.

CONCLUSION

An automated model based algorithm to evaluate CCTA-derived plaque features and quantify morphological features of atherosclerotic plaque increases the ability for MACE prognostication significantly compared to the use of clinical risk factors alone.

Haptoglobin Phenotype Is Associated With High-Density Lipoprotein–Bound Hemoglobin Content and Coronary Endothelial Dysfunction in Patients With Mild Nonobstructive Coronary Artery Disease

Objective—

Coronary endothelial dysfunction (ED) is an early stage of atherosclerosis and is associated with impaired high-density lipoprotein (HDL) function. A functional polymorphism at the haptoglobin (Hp) gene locus (rs72294371) has been associated with marked differences in HDL structure and function. We sought to determine whether Hp phenotype was associated with coronary ED and whether the amount of hemoglobin (Hb) tethered to HDL via Hp was Hp-type dependent and associated with ED.

Approach and Results—

Microvascular and epicardial coronary endothelial function was assessed in 338 individuals with nonobstructive coronary artery disease. Microvascular ED was defined as <50% change in coronary blood flow and epicardial ED as ≥20% decrease in coronary artery diameter after intracoronary acetylcholine infusion. The amount of Hb bound to HDL was measured by ELISA after HDL purification from plasma samples using immune-affinity chromatography. One hundred and seventy of the individuals in this study (50.3%) were diagnosed with microvascular ED, 143 (42.3%) with epicardial ED, and 67 (19.7%) had diabetes mellitus (DM). Hp phenotype was significantly associated with microvascular ( P =0.01) and epicardial ED ( P =0.04) among DM individuals. There was a significant and inverse correlation between the amount of HDL-bound Hb and change in coronary blood flow (r=−0.40; P <0.0001) and in coronary artery diameter (r=−0.44; P <0.0001) in response to acetylcholine infusion. Hb content of HDL was significantly increased in individuals with Hp 2-2 and DM. In a logistic regression model, Hp 2-2 phenotype was associated with microvascular ED (odds ratio, 1.9; P =0.03) and the amount of HDL-bound Hb was an independent predictor of both microvascular (odds ratio, 4.6 for each 1-SD increase; P <0.0001) and epicardial (odds ratio, 2.2; P <0.0001) ED.

Conclusions—

Hp phenotype is significantly associated with coronary ED in DM individuals. This association is likely related to increased Hb tethering to HDL via Hp 2-2 in DM.

Mass Spectrometric Imaging Reveals Temporal and Spatial Dynamics of Bioactive Lipids in Arteries Undergoing Restenosis

Restenosis, or renarrowing of the arterial lumen, is a common recurrent disease following balloon angioplasty and stenting treatments for cardiovascular disease. A major technical barrier for deciphering restenotic mechanisms is the dynamic, spatial profiling of bioactive lipids in the arterial wall, especially in small animals. Here, applying matrix-assisted laser desorption/ionization mass spectrometric imaging (MALDI-MSI), we conducted the first lipidomic study of temporal-spatial profiling in a small animal model of angioplasty-induced restenosis. Cross sections were collected 3, 7, and 14 days after balloon angioplasty of rat carotid arteries. MALDI-MSI analyses showed that diacylglycerols (DAGs), signaling lipids associated with restenosis, and lysophosphatidylcholines (LysoPCs), whose function was uncharacterized in restenosis, dramatically increased at postangioplasty day 7 and day 14 in the neointimal layer of balloon-injured arteries compared to uninjured controls. In contrast, sphingomyelins (SMs) did not increase, but rather decreased at day 3, day 7, and day 14 in injured arteries versus the uninjured control arteries. These results revealed previously unexplored distinct temporal-spatial lipid dynamics in the restenotic arterial wall. Additionally, we employed time-of-flight secondary ion mass spectrometry (TOF-SIMS) tandem MS imaging for both molecular identification and imaging at high spatial resolution. These imaging modalities provide powerful tools for unraveling novel mechanisms of restenosis involving lipids or small signaling molecules.