Group 2 Innate Lymphoid Cells Protect Mice from Abdominal Aortic Aneurysm Formation via IL5 and Eosinophils

Development of abdominal aortic aneurysms (AAA) enhances lesion group-2 innate lymphoid cell (ILC2) accumulation and blood IL5. ILC2 deficiency in Rora^fl/fl Il7r^Cre/+ mice or induced ILC2 depletion in Icos^fl-DTR-fl/+ Cd4^Cre/+ mice expedites AAA growth, increases lesion inflammation, but leads to systemic IL5 and eosinophil (EOS) deficiency. Mechanistic studies show that ILC2 protect mice from AAA formation via IL5 and EOS. IL5 or ILC2 from wild-type (WT) mice, but not ILC2 from Il5^-/- mice induces EOS differentiation in bone-marrow cells from Rora^fl/fl Il7r^Cre/+ mice. IL5, IL13, and EOS or ILC2 from WT mice, but not ILC2 from Il5^-/- and Il13^-/- mice block SMC apoptosis and promote SMC proliferation. EOS but not ILC2 from WT or Il5^-/- mice block endothelial cell (EC) adhesion molecule expression, angiogenesis, dendritic cell differentiation, and Ly6C^hi monocyte polarization. Reconstitution of WT EOS and ILC2 but not Il5^-/- ILC2 slows AAA growth in Rora^fl/fl Il7r^Cre/+ mice by increasing systemic EOS. Besides regulating SMC pathobiology, ILC2 play an indirect role in AAA protection via the IL5 and EOS mechanism.

Association of Interleukin 6 Inhibition With Ziltivekimab and the Neutrophil-Lymphocyte Ratio: A Secondary Analysis of the RESCUE Clinical Trial

Importance

The neutrophil-lymphocyte ratio (NLR) independently predicts atherosclerotic events and is a potential biomarker for residual inflammatory risk. Interleukin (IL) 1β inhibition reduces the NLR, but whether inhibition of IL-6, a cytokine downstream of IL-1, also lowers the NLR is uncertain.

Objective

To evaluate whether ziltivekimab, a therapeutic monoclonal antibody targeting the IL-6 ligand, associates with a lower NLR compared with placebo.

Design, Setting, and Participants

This was an exploratory post hoc analysis of Trial to Evaluate Reduction in Inflammation in Patients With Advanced Chronic Renal Disease Utilizing Antibody Mediated IL-6 Inhibition (RESCUE), a double-blind, randomized, placebo-controlled, phase 2 trial conducted from June 17, 2019, to January 14, 2020, with 24 weeks of follow-up. Participants were enrolled at 40 sites in the US and included adults aged 18 or older with moderate to severe chronic kidney disease and high-sensitivity C-reactive protein levels of 2 mg/L or greater. Data were analyzed from September 28, 2021, to October 2, 2022.

Interventions

Participants were randomly assigned equally to placebo or ziltivekimab, 7.5 mg, 15 mg, or 30 mg, subcutaneously every 4 weeks.

Main Outcomes and Measures

The primary outcome was the change in the NLR at 12 weeks.

Results

A total of 264 participants (median [IQR] age, 68 [60-75] years; 135 men [51%]; 129 women [49%]) were enrolled, of which 187 (71%) had diabetes, and 126 (48%) had known atherosclerosis. The median (IQR) change in the NLR at 12 weeks was 1.56% (IQR, -15.7% to 20.0%), -13.5% (IQR, -31.6% to 3.20%), -14.3% (IQR, -26.9% to 4.62%), and -22.4% (IQR, -33.3% to -4.27%) in the placebo, 7.5-mg, 15-mg, and 30-mg groups, respectively. The estimated treatment difference compared with placebo was -14.6% (95% CI, -24.8% to -4.81%; P = .004), -15.3% (95% CI, -25.2% to -5.10%; P = .004), and -23.6% (95% CI, -33.2% to -14.2%; P < .001) in the 7.5-mg, 15-mg, and 30-mg groups, respectively. A similar reduction in the absolute neutrophil count was observed.

Conclusions and Relevance

Results of this post hoc analysis of the RESCUE trial show that IL-6 ligand inhibition with ziltivekimab associates with a lower NLR, suggesting that it may disrupt multiple atherogenic inflammatory pathways, including those mediated by the myeloid cell compartment. The NLR may have use in monitoring ziltivekimab's efficacy should it be introduced into clinical practice.

Coronary Flow Reserve, Inflammation, and Myocardial Strain: The CIRT-CFR Trial

Inflammation is a key determinant of cardiovascular outcomes, but its role in heart failure is uncertain. In patients with cardiometabolic disease enrolled in the prospective, multicenter ancillary study of CIRT (Cardiovascular Inflammation Reduction Trial), CIRT-CFR (Coronary Flow Reserve to Assess Cardiovascular Inflammation), impaired coronary flow reserve was independently associated with increased inflammation and myocardial strain despite well-controlled lipid, glycemic, and hemodynamic profiles. Inflammation modified the relationship between CFR and myocardial strain, disrupting the association between cardiac blood flow and function. Future studies are needed to investigate whether an early inflammation-mediated reduction in CFR capturing microvascular ischemia may lead to heart failure in patients with cardiometabolic disease. (Cardiovascular Inflammation Reduction Trial [CIRT]; NCT01594333; Coronary Flow Reserve to Assess Cardiovascular Inflammation [CIRT-CFR]; NCT02786134).

Fundamental Pathobiology of Coronary Atherosclerosis and Clinical Implications for Chronic Ischemic Heart Disease Management-The Plaque Hypothesis: A Narrative Review

Importance

Recent clinical and imaging studies underscore that major adverse cardiac events (MACE) outcomes are associated not solely with severe coronary obstructions (ischemia hypothesis or stenosis hypothesis), but with the plaque burden along the entire coronary tree. New research clarifies the pathobiologic mechanisms responsible for plaque development/progression/destabilization leading to MACE (plaque hypothesis), but the translation of these insights to clinical management strategies has lagged. This narrative review elaborates the plaque hypothesis and explicates the current understanding of underlying pathobiologic mechanisms, the provocative destabilizing influences, the diagnostic and therapeutic implications, and their actionable clinical management approaches to optimize the management of patients with chronic coronary disease.

Observations

Clinical trials of management strategies for patients with chronic coronary artery disease demonstrate that while MACE rate increases progressively with the anatomic extent of coronary disease, revascularization of the ischemia-producing obstruction does not forestall MACE. Most severely obstructive coronary lesions often remain quiescent and seldom destabilize to cause a MACE. Coronary lesions that later provoke acute myocardial infarction often do not narrow the lumen critically. Invasive and noninvasive imaging can identify the plaque anatomic characteristics (plaque burden, plaque topography, lipid content) and local hemodynamic/biomechanical characteristics (endothelial shear stress, plaque structural stress, axial plaque stress) that can indicate the propensity of individual plaques to provoke a MACE.

Conclusions and Relevance

The pathobiologic construct concerning the culprit region of a plaque most likely to cause a MACE (plaque hypothesis), which incorporates multiple convergent plaque features, informs the evolution of a new management strategy capable of identifying the high-risk portion of plaque wherever it is located along the course of the coronary artery. Ongoing investigations of high-risk plaque features, coupled with technical advances to enable prognostic characterization in real time and at the point of care, will soon enable evaluation of the entire length of the atheromatous coronary artery and broaden the target(s) of our therapeutic intervention to include all regions of the plaque (both flow limiting and nonflow limiting).

TP53-mediated clonal hematopoiesis confers increased risk for incident atherosclerotic disease

Somatic mutations in blood indicative of clonal hematopoiesis of indeterminate potential (CHIP) are associated with an increased risk of hematologic malignancy, coronary artery disease, and all-cause mortality. Here we analyze the relation between CHIP status and incident peripheral artery disease (PAD) and atherosclerosis, using whole-exome sequencing and clinical data from the UK Biobank and Mass General Brigham Biobank. CHIP associated with incident PAD and atherosclerotic disease across multiple beds, with increased risk among individuals with CHIP driven by mutation in DNA Damage Repair (DDR) genes such as TP53 and PPM1D. To model the effects of DDR-induced CHIP on atherosclerosis, we used a competitive bone marrow transplantation strategy, and generated atherosclerosis-prone Ldlr-/- chimeric mice carrying 20% p53-deficient hematopoietic cells. The chimeric mice were analyzed 13-weeks post-grafting and showed increased aortic plaque size and accumulation of macrophages within the plaque, driven by increased proliferation of p53-deficient plaque macrophages. In summary, our findings highlight the role of CHIP as a broad driver of atherosclerosis across the entire arterial system beyond the coronary arteries, and provide genetic and experimental support for a direct causal contribution of TP53-mutant CHIP to atherosclerosis.

A red wine intervention does not modify plasma trimethylamine N-oxide but is associated with broad shifts in the plasma metabolome and gut microbiota composition

BACKGROUND

Gut microbiota profiles are closely related to cardiovascular diseases through mechanisms that include the reported deleterious effects of metabolites, such as trimethylamine N-oxide (TMAO), which have been studied as diagnostic and therapeutic targets. Moderate red wine (RW) consumption is reportedly cardioprotective, possibly by affecting the gut microbiota.

OBJECTIVES

To investigate the effects of RW consumption on the gut microbiota, plasma TMAO, and the plasma metabolome in men with documented coronary artery disease (CAD) using a multiomics assessment in a crossover trial.

METHODS

We conducted a randomized, crossover, controlled trial involving 42 men (average age, 60 y) with documented CAD comparing 3-wk RW consumption (250 mL/d, 5 d/wk) with an equal period of alcohol abstention, both preceded by a 2-wk washout period. The gut microbiota was analyzed via 16S rRNA high-throughput sequencing. Plasma TMAO was evaluated by LC-MS/MS. The plasma metabolome of 20 randomly selected participants was evaluated by ultra-high-performance LC-MS/MS. The effect of RW consumption was assessed by individual comparisons using paired tests during the abstention and RW periods.

RESULTS

Plasma TMAO did not differ between RW intervention and alcohol abstention, and TMAO concentrations showed low intraindividual concordance over time, with an intraclass correlation coefficient of 0.049 during the control period. After RW consumption, there was significant remodeling of the gut microbiota, with a difference in β diversity and predominance of Parasutterella, Ruminococcaceae, several Bacteroides species, and Prevotella. Plasma metabolomic analysis revealed significant changes in metabolites after RW consumption, consistent with improved redox homeostasis.

CONCLUSIONS

Modulation of the gut microbiota may contribute to the putative cardiovascular benefits of moderate RW consumption. The low intraindividual concordance of TMAO presents challenges regarding its role as a cardiovascular risk biomarker at the individual level. This study was registered at clinical trials.gov as NCT03232099.

Differential IL18 signaling via IL18 receptor and Na-Cl co-transporter discriminating thermogenesis and glucose metabolism regulation

White adipose tissue (WAT) plays a role in storing energy, while brown adipose tissue (BAT) is instrumental in the re-distribution of stored energy when dietary sources are unavailable. Interleukin-18 (IL18) is a cytokine playing a role in T-cell polarization, but also for regulating energy homeostasis via the dimeric IL18 receptor (IL18r) and Na-Cl co-transporter (NCC) on adipocytes. Here we show that IL18 signaling in metabolism is regulated at the level of receptor utilization, with preferential role for NCC in brown adipose tissue (BAT) and dominantly via IL18r in WAT. In Il18r^-/-Ncc^-/- mice, high-fat diet (HFD) causes more prominent body weight gain and insulin resistance than in wild-type mice. The WAT insulin resistance phenotype of the double-knockout mice is recapitulated in HFD-fed Il18r^-/- mice, whereas decreased thermogenesis in BAT upon HFD is dependent on NCC deletion. BAT-selective depletion of either NCC or IL18 reduces thermogenesis and increases BAT and WAT inflammation. IL18r deletion in WAT reduces insulin signaling and increases WAT inflammation. In summary, our study contributes to the mechanistic understanding of IL18 regulation of energy metabolism and shows clearly discernible roles for its two receptors in brown and white adipose tissues.

Inflammation drives residual risk in chronic kidney disease: a CANTOS substudy

AIMS

Hyperlipidaemia and inflammation jointly contribute to atherosclerotic disease. Yet, after the initiation of statin therapy, the relative contributions of these processes may differ in patient groups, such as those with and without impaired kidney function.

METHODS AND RESULTS

Among 9151 stable statin-treated post-myocardial infarction patients participating in the CANTOS trial, the contributions of residual cholesterol risk and residual inflammatory risk were evaluated as determinants of recurrent major adverse cardiovascular events (MACE) and total mortality, stratified by baseline estimated glomerular filtration rate (eGFR) above or below 60 mL/min/1.73 m2 using the race agnostic CKD-EPI 2021 formula (all participants had eGFR > 30 mL/min/1.73 m2). Analyses of residual inflammatory risk focused on high-sensitivity C-reactive protein (hsCRP) and interleukin-6 (IL-6) while analyses of residual cholesterol risk focused on LDL-cholesterol (LDL-C) and non-HDL-cholesterol (non-HDL-C). Participants were followed for a period of up to 5 years (median 3.7 years). Median baseline levels of LDL-C and hsCRP were 81 mg/dL and 4.2 mg/L. Among participants with eGFR ≥ 60 mL/min/1.73 m2, increasing quartiles of plasma hsCRP, IL-6, LDL-C, and non-HDL-C all positively associated with risks of recurrent MACE [hazard ratios (HR) comparing the top to bottom quartile for hsCRP 1.45; for IL-6 2.48; for LDL-C 1.64; and for non-HDL-C 1.68] (all P < 0.0001). By contrast, among those with eGFR < 60 mL/min/1.73 m2, increasing quartiles of hsCRP and IL-6 significantly predicted recurrent MACE [HR comparing the top to bottom quartile for hsCRP 1.50 (P = 0.021); for IL-6 1.84 (P = 0.048)], whereas increasing quartiles of LDL-C and non-HDL-C did not [HR comparing the top to bottom quartile for LDL-C 1.04 (P = 0.80); for non-HDL-C 0.98 (P = 0.88)]. The predictive utility of hsCRP and IL-6 in the setting of eGFR < 60 mL/min/1.73 m2 remained significant after adjustment for a wide range of potential confounding factors including age, sex, smoking status, blood pressure, body mass index, and diabetes. For the endpoint of total mortality, both hsCRP (HR 1.77, P = 0.0021) and IL-6 (HR 2.15, P = 0.015) were significant predictors among those with eGFR < 60 mL/min/1.73 m2, whereas LDL-C (HR 0.91, P = 0.56) and non-HDL-C (HR 0.85, P = 0.31) were not. Similar effects were observed in analyses stratified by the albumin to creatinine ratio rather than eGFR.

CONCLUSION

Among atherosclerosis patients with impaired kidney function already aggressively treated with statin therapy, residual inflammatory risk plays a substantial role in determining the risk of recurrent cardiovascular events. These data have implications for risk stratification of individuals with chronic kidney disease and for the development of novel agents that target inflammatory processes in this high-risk group of patients.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov: NCT01327846.

Triglyceride Lowering with Pemafibrate to Reduce Cardiovascular Risk

BACKGROUND

High triglyceride levels are associated with increased cardiovascular risk, but whether reductions in these levels would lower the incidence of cardiovascular events is uncertain. Pemafibrate, a selective peroxisome proliferator-activated receptor α modulator, reduces triglyceride levels and improves other lipid levels.

METHODS

In a multinational, double-blind, randomized, controlled trial, we assigned patients with type 2 diabetes, mild-to-moderate hypertriglyceridemia (triglyceride level, 200 to 499 mg per deciliter), and high-density lipoprotein (HDL) cholesterol levels of 40 mg per deciliter or lower to receive pemafibrate (0.2-mg tablets twice daily) or matching placebo. Eligible patients were receiving guideline-directed lipid-lowering therapy or could not receive statin therapy without adverse effects and had low-density lipoprotein (LDL) cholesterol levels of 100 mg per deciliter or lower. The primary efficacy end point was a composite of nonfatal myocardial infarction, ischemic stroke, coronary revascularization, or death from cardiovascular causes.

RESULTS

Among 10,497 patients (66.9% with previous cardiovascular disease), the median baseline fasting triglyceride level was 271 mg per deciliter, HDL cholesterol level 33 mg per deciliter, and LDL cholesterol level 78 mg per deciliter. The median follow-up was 3.4 years. As compared with placebo, the effects of pemafibrate on lipid levels at 4 months were -26.2% for triglycerides, -25.8% for very-low-density lipoprotein (VLDL) cholesterol, -25.6% for remnant cholesterol (cholesterol transported in triglyceride-rich lipoproteins after lipolysis and lipoprotein remodeling), -27.6% for apolipoprotein C-III, and 4.8% for apolipoprotein B. A primary end-point event occurred in 572 patients in the pemafibrate group and in 560 of those in the placebo group (hazard ratio, 1.03; 95% confidence interval, 0.91 to 1.15), with no apparent effect modification in any prespecified subgroup. The overall incidence of serious adverse events did not differ significantly between the groups, but pemafibrate was associated with a higher incidence of adverse renal events and venous thromboembolism and a lower incidence of nonalcoholic fatty liver disease.

CONCLUSIONS

Among patients with type 2 diabetes, mild-to-moderate hypertriglyceridemia, and low HDL and LDL cholesterol levels, the incidence of cardiovascular events was not lower among those who received pemafibrate than among those who received placebo, although pemafibrate lowered triglyceride, VLDL cholesterol, remnant cholesterol, and apolipoprotein C-III levels. (Funded by the Kowa Research Institute; PROMINENT ClinicalTrials.gov number, NCT03071692.).

Proprotein Convertase Subtilisin/Kexin 9 (PCSK9) Promotes Macrophage Activation via LDL Receptor-Independent Mechanisms

BACKGROUND

Activated macrophages contribute to the pathogenesis of vascular disease. Vein graft failure is a major clinical problem with limited therapeutic options. PCSK9 (proprotein convertase subtilisin/kexin 9) increases low-density lipoprotein (LDL)-cholesterol levels via LDL receptor (LDLR) degradation. The role of PCSK9 in macrophage activation and vein graft failure is largely unknown, especially through LDLR-independent mechanisms. This study aimed to explore a novel mechanism of macrophage activation and vein graft disease induced by circulating PCSK9 in an LDLR-independent fashion.

METHODS

We used Ldlr^-/- mice to examine the LDLR-independent roles of circulating PCSK9 in experimental vein grafts. Adeno-associated virus (AAV) vector encoding a gain-of-function mutant of PCSK9 (rAAV8/D377Y-mPCSK9) induced hepatic PCSK9 overproduction. To explore novel inflammatory targets of PCSK9, we used systems biology in Ldlr^-/- mouse macrophages.

RESULTS

In Ldlr^-/- mice, AAV-PCSK9 increased circulating PCSK9, but did not change serum cholesterol and triglyceride levels. AAV-PCSK9 promoted vein graft lesion development when compared with control AAV. In vivo molecular imaging revealed that AAV-PCSK9 increased macrophage accumulation and matrix metalloproteinase activity associated with decreased fibrillar collagen, a molecular determinant of atherosclerotic plaque stability. AAV-PCSK9 induced mRNA expression of the pro-inflammatory mediators IL-1β (interleukin-1 beta), TNFα (tumor necrosis factor alpha), and MCP-1 (monocyte chemoattractant protein-1) in peritoneal macrophages underpinned by an in vitro analysis of Ldlr^-/- mouse macrophages stimulated with endotoxin-free recombinant PCSK9. A combination of unbiased global transcriptomics and new network-based hyperedge entanglement prediction analysis identified the NF-κB (nuclear factor-kappa B) signaling molecules, lectin-like oxidized LOX-1 (LDL receptor-1), and SDC4 (syndecan-4) as potential PCSK9 targets mediating pro-inflammatory responses in macrophages.

CONCLUSIONS

Circulating PCSK9 induces macrophage activation and vein graft lesion development via LDLR-independent mechanisms. PCSK9 may be a potential target for pharmacologic treatment for this unmet medical need.

Biomarkers associated with coronary high-risk plaques

Vascular inflammation, lipid metabolism, and thrombogenicity play a key role not only in atherogenesis but also in the development of acute coronary syndromes. Biomarkers associated with coronary high-risk plaques defined according to intravascular imaging have not been systematically studied. A total of 69 patients with coronary artery disease who underwent both optical coherence tomography and intravascular ultrasound imaging, and who provided blood specimens were included. Comprehensive biomarkers for inflammation, lipid, and coagulation were analyzed. Composite models sought biomarker patterns associated with thin-cap fibroatheroma (TCFA) and "high-risk plaques" (TCFA and large plaque burden). Two different composite models were developed for TCFA, based on the finding that high sensitivity C-reactive protein (hsCRP), plasminogen activator inhibitor-1, fibrinogen, IL-6, homocysteine and amyloid A levels were elevated, and high-density lipoprotein cholesterol (HDL) and bile acid levels were decreased in these patients. Both composite models were highly accurate for detecting patients with TCFA (area under curve [AUC]: 0.883 in model-A and 0.875 in model-B, both p < 0.001). In addition, creatinine, hsCRP, fibrinogen, tumor necrosis factor-α, IL-6, homocysteine, amyloid A, HDL, prothrombin, and bile acid were useful for detecting patients with "high-risk plaques". Two composite models were highly accurate for detection of patients with "high-risk plaques" (AUC: 0.925 in model-A and 0.947 in model-B, both p < 0.001). Biomarkers useful for detection of patients with high-risk coronary plaques defined according to intravascular imaging have been identified. These biomarkers may be useful to risk stratify patients and to develop targeted therapy.Clinical Trial Registration https://www.umin.ac.jp/ctr/ , UMIN000041692. Biomarkers and high-risk plaques hsCRP, PAI-1, fibrinogen, IL-6, homocysteine, amyloid A, HDL, and bile acid were useful for detecting patients with TCFA. hsCRP, fibrinogen, IL-6, homocysteine, amyloid A, creatinine, TNFα, HDL, prothrombin, and bile acid were useful for detecting patients with "high-risk plaques" (plaque which has both TCFA and large plaque burden). White arrowhead denotes TCFA. Red and green dashed lines denote lumen area and external elastic membrane area, respectively.

The effect of ziltivekimab on the neutrophil-lymphocyte ratio: analysis from RESCUE

Background

The neutrophil-lymphocyte ratio (NLR), derived from the complete blood count, independently predicts atherosclerotic events and is a potential biomarker for residual inflammatory risk. A previous study showed that interleukin (IL)-1β inhibition reduces the NLR, but whether inhibition with IL-6, a cytokine downstream of IL-1, also lowers the NLR is unknown.

Purpose

To evaluate whether ziltivekimab, a monoclonal antibody targeting the IL-6 ligand, dose-dependently lowers the NLR compared to placebo.

Methods

The phase II RESCUE trial randomized 264 patients with moderate to severe chronic kidney disease (CKD) and high-sensitivity CRP (hsCRP) &gt;2mg/L in a 1:1:1:1 ratio to placebo or ziltivekimab 7.5 mg, 15 mg, and 30 mg subcutaneously once every four weeks. As previously reported, the trial met its primary endpoint as demonstrated by hsCRP reductions of 4% in the placebo group as compared to 77%, 88%, and 92% at 12 weeks in the ziltivekimab 7.5, 15, and 30 mg groups, respectively. Using RESCUE trial data, we further evaluated the percent change from baseline in the NLR at 12 weeks and sought evidence of correlation between any observed changes in the NLR with changes in other measured biomarkers.

Results

Ziltivekimab dose-dependently reduced the NLR starting at week one and sustained through week 12 (Table). The median change in the NLR at 12 weeks, the primary pre-specified endpoint, was −13.5% in the 7.5 mg group, −14.3% in the 15 mg group, and −22.4% in the 30 mg group compared to 1.56% in the placebo group. The estimated treatment difference was −14.6% (p=0.004), −15.3% (p=0.004), and −23.6% (p&lt;0.0001) in the ziltivekimab 7.5, 15, and 30 mg groups respectively. These changes were driven largely by reductions in the absolute neutrophil count with minimal change in lymphocyte count. The change in NLR with ziltivekimab correlated modestly with the changes in hsCRP (R=0.26, p=0.0006), fibrinogen (R=0.18, p=0.02), and haptoglobin (R=0.17, p=0.03), but not serum amyloid A, ApoA1, ApoB, ApoB/ApoA ratio, or traditional risk markers.

Conclusions

IL-6 inhibition with ziltivekimab lowers the NLR. The ongoing ZEUS cardiovascular (CV) outcomes trial will assess whether ziltivekimab can reduce CV event rates among individuals with stage 3 to 4 CKD, known atherosclerotic disease, and elevated hsCRP. If ziltivekimab reduces CV risk, it would provide further evidence for critical inter-relationships between bone marrow function and atherothrombosis.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Novo Nordisk

Coronary plaque characteristics associated with major adverse cardiovascular events in atherosclerotic patients and lesions – a systematic review and meta-analysis

Background

The clinical value of high-risk coronary plaque characteristics (CPCs) to inform intensified medical therapy or revascularization of non-flow-limiting lesion remains uncertain.

Purpose

We performed a systematic review and meta-analysis to study the prognostic impact of CPCs on patient-level and lesion-level major cardiovascular adverse events (MACE).

Methods

We systematically reviewed MEDLINE, EMBASE, and the Cochrane database for studies evaluating the association of CPC with patient-level and lesion-level MACE. CPCs included high plaque burden, low minimal lumen area, thin cap fibroatheroma, high lipid core burden index, low attenuation plaque, spotty calcification, napkin ring sign, or positive remodelling.

Results

Thirty studies (21 retrospective, 9 prospective) with 30,369 patients were included. CPCs were evaluated by invasive intravascular techniques in 9 studies (optical coherence tomography=4, intravascular ultrasound imaging=3, near-infrared spectroscopy intravascular ultrasound imaging=2) and by coronary computed tomography angiography (CCTA) in 21 studies. CPCs significantly predicted patient-level and lesion-level MACE in both unadjusted and adjusted analyses. For each CPC, the risks were higher for lesion-level (HR range 3.2–16.8) as compared with patient-level MACE (HR range 1.8–4.1). Accuracy was modest to good for most CPCs at the patient-level (AUC for MACE ranging between 0.53 and 0.84) and moderate to good for most CPCs at the lesion-level (AUC for MACE ranging between 0.71 and 0.83). Plaques with more than one CPC had the highest accuracy for lesion-level MACE (AUC 0.87, 95% CI 0.84–0.90). The pooled sensitivities of CPCs for lesion-level MACE ranged between 40% and 63% and specificities between 73% and 98%. As the pooled prevalence of CPCs among plaques was low (3% to 28%), the estimated positive predictive values for lesion-level MACE were modest (range 1% to 26%).

Conclusions

CCTA and intravascular imaging characterization of CPCs identifies high-risk atherosclerotic plaques that place lesions and patients at risk for future MACE, albeit with modest sensitivity and positive predictive value (PROSPERO identifier: CRD42021251810).

Funding Acknowledgement

Type of funding sources: None.

Optical coherence tomography in coronary atherosclerosis assessment and intervention

Since optical coherence tomography (OCT) was first performed in humans two decades ago, this imaging modality has been widely adopted in research on coronary atherosclerosis and adopted clinically for the optimization of percutaneous coronary intervention. In the past 10 years, substantial advances have been made in the understanding of in vivo vascular biology using OCT. Identification by OCT of culprit plaque pathology could potentially lead to a major shift in the management of patients with acute coronary syndromes. Detection by OCT of healed coronary plaque has been important in our understanding of the mechanisms involved in plaque destabilization and healing with the rapid progression of atherosclerosis. Accurate detection by OCT of sequelae from percutaneous coronary interventions that might be missed by angiography could improve clinical outcomes. In addition, OCT has become an essential diagnostic modality for myocardial infarction with non-obstructive coronary arteries. Insight into neoatherosclerosis from OCT could improve our understanding of the mechanisms of very late stent thrombosis. The appropriate use of OCT depends on accurate interpretation and understanding of the clinical significance of OCT findings. In this Review, we summarize the state of the art in cardiac OCT and facilitate the uniform use of this modality in coronary atherosclerosis. Contributions have been made by clinicians and investigators worldwide with extensive experience in OCT, with the aim that this document will serve as a standard reference for future research and clinical application.

Pathway-Specific Polygenic Risk Scores Identify Obstructive Sleep Apnea-Related Pathways Differentially Moderating Genetic Susceptibility to Coronary Artery Disease

BACKGROUND

Obstructive sleep apnea (OSA) and its features, such as chronic intermittent hypoxia, may differentially affect specific molecular pathways and processes in the pathogenesis of coronary artery disease (CAD) and influence the subsequent risk and severity of CAD events. In particular, competing adverse (eg, inflammatory) and protective (eg, increased coronary collateral blood flow) mechanisms may operate, but remain poorly understood. We hypothesize that common genetic variation in selected molecular pathways influences the likelihood of CAD events differently in individuals with and without OSA, in a pathway-dependent manner.

METHODS

We selected a cross-sectional sample of 471 877 participants from the UK Biobank, with 4974 ascertained to have OSA, 25 988 to have CAD, and 711 to have both. We calculated pathway-specific polygenic risk scores for CAD, based on 6.6 million common variants evaluated in the CARDIoGRAMplusC4D genome-wide association study (Coronary ARtery DIsease Genome wide Replication and Meta-analysis [CARDIoGRAM] plus The Coronary Artery Disease [C4D] Genetics), annotated to specific genes and pathways using functional genomics databases. Based on prior evidence of involvement with intermittent hypoxia and CAD, we tested pathway-specific polygenic risk scores for the HIF1 (hypoxia-inducible factor 1), VEGF (vascular endothelial growth factor), NFκB (nuclear factor kappa-light-chain-enhancer of activated B cells) and TNF (tumor necrosis factor) signaling pathways.

RESULTS

In a multivariable-adjusted logistic generalized additive model, elevated pathway-specific polygenic risk scores for the Kyoto Encyclopedia of Genes and Genomes VEGF pathway (39 genes) associated with protection for CAD in OSA (interaction odds ratio 0.86, P=6×10-4). By contrast, the genome-wide CAD PRS did not show evidence of statistical interaction with OSA.

CONCLUSIONS

We find evidence that pathway-specific genetic risk of CAD differs between individuals with and without OSA in a qualitatively pathway-dependent manner. These results provide evidence that gene-by-environment interaction influences CAD risk in certain pathways among people with OSA, an effect that is not well-captured by the genome-wide PRS. This invites further study of how OSA interacts with genetic risk at the molecular level and suggests eventual personalization of OSA treatment to reduce CAD risk according to individual pathway-specific genetic risk profiles.

Group 2 innate lymphoid cells protect mouse heart from myocardial infarction injury via interleukin 5, eosinophils, and dendritic cells

AIMS

Group 2 innate lymphoid cells (ILC2) regulate adaptive and innate immunities. In mouse heart, production of myocardial infarction (MI) increased ILC2 accumulation, suggesting a role for ILC2 in cardiac dysfunction post-MI.

METHODS AND RESULTS

We produced MI in ILC2-deficeint Rorafl/flIl7rCre/+ mice and in Icosfl-DTR-fl/+Cd4Cre/+ mice that allowed diphtheria toxin-induced ILC2 depletion. Genetic or induced deficiency of ILC2 in mice exacerbated cardiac dysfunction post-MI injury along with increased myocardial accumulation of neutrophils, CD11b+Ly6Chi monocytes, and CD4+ T cells but deficiency of eosinophils (EOS) and dendritic cells (DC). Post-MI hearts from genetic and induced ILC2-deficient mice contained many more apoptotic cells than those of control mice, and Rorafl/flIl7rCre/+ mice showed thinner and larger infarcts and more collagen-I depositions than the Il7rCre/+ mice only at early time points post-MI. Mechanistic studies revealed elevated blood IL5 in Il7rCre/+ mice at 1, 7, and 28 days post-MI. Such increase was blunted in Rorafl/flIl7rCre/+ mice. Administration of recombinant IL5 reversed EOS losses in Rorafl/flIl7rCre/+ mice, but IL5 did not correct the DC loss in these mice. Adoptive transfer of ILC2, EOS, or DC from wild-type mice, but not ILC2 from Il5-/- mice improved post-MI cardiac functions in Rorafl/flIl7rCre/+ recipient mice. EOS are known to protect cardiomyocytes from apoptosis. Here we showed that DC acted like EOS in blocking cardiomyocyte apoptosis. Yet, ILC2 or IL5 alone did not directly affect cardiomyocyte apoptosis or TGF-β-induced cardiac fibroblast Smad signaling.

CONCLUSION

This study revealed an indirect cardiac reparative role of ILC2 in post-MI hearts via the IL5, EOS, and DC mechanism.

Cardiorenal risk of celecoxib compared with naproxen or ibuprofen in arthritis patients: insights from the PRECISION trial

AIMS

Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most frequently used drugs, both prescribed and over the counter. The long-term cardiovascular safety of NSAIDs in patients with arthritis has engendered controversy. Concerns remain regarding the relative incidence and severity of adverse cardiorenal effects, particularly in arthritis patients with established cardiovascular (CV) disease or risk factors for disease as illustrated by the PRECISION (Prospective Randomized Evaluation of Celecoxib Integrated Safety vs. Ibuprofen Or Naproxen) trial participants (NCT00346216).We further investigated whether the selective COX-2 Inhibitor celecoxib has a superior cardiorenal safety profile compared with ibuprofen or naproxen in the PRECISION population.

METHODS AND RESULTS

Twenty-four thousand eighty-one patients who required NSAIDs for osteoarthritis or rheumatoid arthritis (RA) and had increased CV risk randomly received celecoxib, ibuprofen, or naproxen. The current pre-specified secondary analysis assessed the incidence, severity, and NSAID-related risk of the pre-specified composite cardiorenal outcome (adjudicated renal event, hospitalization for congestive heart failure, or hospitalization for hypertension) in the intention-to-treat (ITT) population. An on-treatment analysis assessed safety in those taking the study medication. Following a mean treatment duration of 20.3 ± 16.0 months and a mean follow-up of 34.1 ± 13.4 months, the primary cardiorenal composite outcome occurred in 423 patients (1.76%) in the ITT population. Of these 423 patients, 118 (28%) were in the celecoxib, 166 (39%) in the ibuprofen, and 139 (33%) in the naproxen group. In a multivariable Cox regression model adjusted for independent clinical variables, celecoxib showed a significantly lower risk compared with ibuprofen [hazard ratio (HR) 0.67, confidence interval (CI) 0.53-0.85, P = 0.001) and a trend to lower risk compared with naproxen (HR 0.79, CI 0.61-1.00, P = 0.058). In the ITT analysis, clinically significant renal events occurred in 220 patients with events rates of 0.71%, 1.14%, and 0.89% for celecoxib, ibuprofen, and naproxen, respectively (P = 0.052), while in the on-treatment analysis the rates were 0.52%, 0.91%, and 0.78% (P &amp;lt; 0.001).

CONCLUSION

In the current era, long-term NSAID use was associated with few cardiorenal events in arthritis patients. At the doses studied, celecoxib displayed fewer renal events and hence more favourable cardiovascular safety compared with ibuprofen or naproxen. These results have considerable clinical implications for practitioners managing individuals with chronic arthritis pain and high risk of impaired renal function and/or heart failure.Clinical Trial Registration: NCT00346216.

Identifying novel mechanisms of abdominal aortic aneurysm via unbiased proteomics and systems biology

Background

Abdominal aortic aneurysm (AAA), characterized by a continued expansion of the aorta, leads to rupture if not surgically repaired. Mice aid the study of disease progression and its underlying mechanisms since sequential studies of aneurysm development are not feasible in humans. The present study used unbiased proteomics and systems biology to understand the molecular relationship between the mouse models of AAA and the human disease.

Methods and results

Aortic tissues of developing and established aneurysms produced by either angiotensin II (AngII) infusion in Apoe -/- and Ldlr -/- mice or intraluminal elastase incubation in wildtype C57BL/6J mice were examined. Aortas were dissected free and separated into eight anatomical segments for proteomics in comparison to their appropriate controls. High-dimensional proteome cluster analyses identified site-specific protein signatures in the suprarenal segment for AngII-infused mice (159 for Apoe -/- and 158 for Ldlr -/-) and the infrarenal segment for elastase-incubated mice (173). Network analysis revealed a predominance of inflammatory and coagulation factors in developing aneurysms, and a predominance of fibrosis-related pathways in established aneurysms for both models. To further substantiate our discovery platform, proteomics was performed on human infrarenal aortic aneurysm tissues as well as aortic tissue collected from age-matched controls. Protein processing and inflammatory pathways, particularly neutrophil-associated inflammation, dominated the proteome of the human aneurysm abdominal tissue. Aneurysmal tissue from both mouse and human had inflammation, coagulation, and protein processing signatures, but differed in the prevalence of neutrophil-associated pathways, and erythrocyte and oxidative stress-dominated networks in the human aneurysms.

Conclusions

Identifying changes unique to each mouse model will help to contextualize model-specific findings. Focusing on shared proteins between mouse experimental models or between mouse and human tissues may help to better understand the mechanisms for AAA and establish molecular bases for novel therapies.

ApoA-I Infusion Therapies Following Acute Coronary Syndrome: Past, Present, and Future

PURPOSE OF REVIEW

The elevated adverse cardiovascular event rate among patients with low high-density lipoprotein cholesterol (HDL-C) formed the basis for the hypothesis that elevating HDL-C would reduce those events. Attempts to raise endogenous HDL-C levels, however, have consistently failed to show improvements in cardiovascular outcomes. However, steady-state HDL-C concentration does not reflect the function of this complex family of particles. Indeed, HDL functions correlate only weakly with serum HDL-C concentration. Thus, the field has pivoted from simply raising the quantity of HDL-C to a focus on improving the putative anti-atherosclerotic functions of HDL particles. Such functions include the ability of HDL to promote the efflux of cholesterol from cholesterol-laden macrophages. Apolipoprotein A-I (apoA-I), the signature apoprotein of HDL, may facilitate the removal of cholesterol from atherosclerotic plaque, reduce the lesional lipid content and might thus stabilize vulnerable plaques, thereby reducing the risk of cardiac events. Infusion of preparations of apoA-I may improve cholesterol efflux capacity (CEC). This review summarizes the development of apoA-I therapies, compares their structural and functional properties and discusses the findings of previous studies including their limitations, and how CSL112, currently being tested in a phase III trial, may overcome these challenges.

RECENT FINDINGS

Three major ApoA-I-based approaches (MDCO-216, CER-001, and CSL111/CSL112) have aimed to enhance reverse cholesterol transport. These three therapies differ considerably in both lipid and protein composition. MDCO-216 contains recombinant ApoA-I Milano, CER-001 contains recombinant wild-type human ApoA-I, and CSL111/CSL112 contains native ApoA-I isolated from human plasma. Two of the three agents studied to date (apoA-1 Milano and CER-001) have undergone evaluation by intravascular ultrasound imaging, a technique that gauges lesion volume well but does not assess other important variables that may relate to clinical outcomes. ApoA-1 Milano and CER-001 reduce lecithin-cholesterol acyltransferase (LCAT) activity, potentially impairing the function of HDL in reverse cholesterol transport. Furthermore, apoA-I Milano can compete with and alter the function of the recipient's endogenous apoA-I. In contrast to these agents, CSL112, a particle formulated using human plasma apoA-I and phosphatidylcholine, increases LCAT activity and does not lead to the malfunction of endogenous apoA-I. CSL112 robustly increases cholesterol efflux, promotes reverse cholesterol transport, and now is being tested in a phase III clinical trial. Phase II-b studies of MDCO-216 and CER-001 failed to produce a significant reduction in coronary plaque volume as assessed by IVUS. However, the investigation to determine whether the direct infusion of a reconstituted apoA-I reduces post-myocardial infarction coronary events is being tested using CSL112, which is dosed at a higher level than MDCO-216 and CER-001 and has more favorable pharmacodynamics.

A biological rationale for the disparate effects of omega-3 fatty acids on cardiovascular disease outcomes

The omega-3 fatty acids (n3-FAs) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) rapidly incorporate into cell membranes where they modulate signal transduction pathways, lipid raft formation, and cholesterol distribution. Membrane n3-FAs also form specialized pro-resolving mediators and other intracellular oxylipins that modulate inflammatory pathways, including T-cell differentiation and gene expression. Cardiovascular (CV) trials have shown that EPA, administered as icosapent ethyl (IPE), reduces composite CV events, along with plaque volume, in statin-treated, high-risk patients. Mixed EPA/DHA regimens have not shown these benefits, perhaps as the result of differences in formulation, dosage, or potential counter-regulatory actions of DHA. Indeed, EPA and DHA have distinct, tissue-specific effects on membrane structural organization and cell function. This review summarizes: (1) results of clinical outcome and imaging trials using n3-FA formulations; (2) membrane interactions of n3-FAs; (3) effects of n3-FAs on membrane oxidative stress and cholesterol crystalline domain formation during hyperglycemia; (4) n3-FA effects on endothelial function; (5) role of n3-FA-generated metabolites in inflammation; and (6) ongoing and future clinical investigations exploring treatment targets for n3-FAs, including COVID-19.

Cardiovascular Disease in Myeloproliferative Neoplasms: JACC: CardioOncology State-of-the-Art Review

Myeloproliferative neoplasms are associated with increased risk for thrombotic complications. These conditions most commonly involve somatic mutations in genes that lead to constitutive activation of the Janus-associated kinase signaling pathway (eg, Janus kinase 2, calreticulin, myeloproliferative leukemia protein). Acquired gain-of-function mutations in these genes, particularly Janus kinase 2, can cause a spectrum of disorders, ranging from clonal hematopoiesis of indeterminate potential, a recently recognized age-related promoter of cardiovascular disease, to frank hematologic malignancy. Beyond thrombosis, patients with myeloproliferative neoplasms can develop other cardiovascular conditions, including heart failure and pulmonary hypertension. The authors review the pathophysiologic mechanisms of cardiovascular complications of myeloproliferative neoplasms, which involve inflammation, prothrombotic and profibrotic factors (including transforming growth factor-beta and lysyl oxidase), and abnormal function of circulating clones of mutated leukocytes and platelets from affected individuals. Anti-inflammatory therapies may provide cardiovascular benefit in patients with myeloproliferative neoplasms, a hypothesis that requires rigorous evaluation in clinical trials.

Genome-wide pleiotropy analysis of coronary artery disease and pneumonia identifies shared immune pathways

Coronary artery disease (CAD) remains the leading cause of death despite scientific advances. Elucidating shared CAD/pneumonia pathways may reveal novel insights regarding CAD pathways. We performed genome-wide pleiotropy analyses of CAD and pneumonia, examined the causal effects of the expression of genes near independently replicated SNPs and interacting genes with CAD and pneumonia, and tested interactions between disruptive coding mutations of each pleiotropic gene and smoking status on CAD and pneumonia risks. Identified pleiotropic SNPs were annotated to ADAMTS7 and IL6R. Increased ADAMTS7 expression across tissues consistently showed decreased risk for CAD and increased risk for pneumonia; increased IL6R expression showed increased risk for CAD and decreased risk for pneumonia. We similarly observed opposing CAD/pneumonia effects for NLRP3. Reduced ADAMTS7 expression conferred a reduced CAD risk without increased pneumonia risk only among never-smokers. Genetic immune-inflammatory axes of CAD linked to respiratory infections implicate ADAMTS7 and IL6R, and related genes.

Mendelian randomization supports bidirectional causality between telomere length and clonal hematopoiesis of indeterminate potential

Human genetic studies support an inverse causal relationship between leukocyte telomere length (LTL) and coronary artery disease (CAD), but directionally mixed effects for LTL and diverse malignancies. Clonal hematopoiesis of indeterminate potential (CHIP), characterized by expansion of hematopoietic cells bearing leukemogenic mutations, predisposes both hematologic malignancy and CAD. TERT (which encodes telomerase reverse transcriptase) is the most significantly associated germline locus for CHIP in genome-wide association studies. Here, we investigated the relationship between CHIP, LTL, and CAD in the Trans-Omics for Precision Medicine (TOPMed) program (n = 63,302) and UK Biobank (n = 47,080). Bidirectional Mendelian randomization studies were consistent with longer genetically imputed LTL increasing propensity to develop CHIP, but CHIP then, in turn, hastens to shorten measured LTL (mLTL). We also demonstrated evidence of modest mediation between CHIP and CAD by mLTL. Our data promote an understanding of potential causal relationships across CHIP and LTL toward prevention of CAD.

TET2-Driven Clonal Hematopoiesis and Response to Canakinumab: An Exploratory Analysis of the CANTOS Randomized Clinical Trial

Importance

Clonal hematopoiesis of indeterminate potential (CHIP) is associated with increased risk of atherosclerotic cardiovascular disease, and mouse experiments suggest that CHIP related to Tet2 loss of function in myeloid cells accelerates atherosclerosis via augmented interleukin (IL) 1β signaling.

Objective

To assess whether individuals with CHIP have greater cardiovascular event reduction in response to IL-1β neutralization in the Canankinumab Anti-inflammatory Thrombosis Outcomes Trial (CANTOS).

Design, Setting, and Participants

This randomized clinical trial took place from April 2011 to June 2017 at more than 1000 clinical sites in 39 countries. Targeted deep sequencing of genes previously associated with CHIP in a subset of trial participants using genomic DNA prepared from baseline peripheral blood samples were analyzed. All participants had prior myocardial infarction and elevated high-sensitivity C-reactive protein level above 0.20 mg/dL. Analysis took place between June 2017 and December 2021.

Interventions

Canakinumab, an anti-IL-1β antibody, given at doses of 50, 150, and 300 mg once every 3 months.

Main Outcomes and Measures

Major adverse cardiovascular events (MACE).

Results

A total of 338 patients (8.6%) were identified in this subset with evidence for clonal hematopoiesis. As expected, the incidence of CHIP increased with age; the mean (SD) age of patients with CHIP was 66.3 (9.2) years and 61.5 (9.6) years in patients without CHIP. Unlike other populations that were not preselected for elevated C-reactive protein, in the CANTOS population variants in TET2 were more common than DNMT3A (119 variants in 103 patients vs 86 variants in 85 patients). Placebo-treated patients with CHIP showed a nonsignificant increase in the rate of MACE compared with patients without CHIP using a Cox proportional hazard model (hazard ratio, 1.32 [95% CI, 0.86-2.04]; P = .21). Exploratory analyses of placebo-treated patients with a somatic variant in either TET2 or DNMT3A (n = 58) showed an equivocal risk for MACE (hazard ratio, 1.65 [95% CI, 0.97-2.80]; P = .06). Patients with CHIP due to somatic variants in TET2 also had reduced risk for MACE while taking canakinumab (hazard ratio, 0.38 [95% CI, 0.15-0.96]) with equivocal difference compared with others (P for interaction = .14).

Conclusions and Relevance

These results are consistent with observations of increased risk for cardiovascular events in patients with CHIP and raise the possibility that those with TET2 variants may respond better to canakinumab than those without CHIP. Future studies are required to further substantiate this hypothesis.

Trial Registration

ClinicalTrials.gov Identifier: NCT01327846.

B lymphocyte-derived acetylcholine limits steady-state and emergency hematopoiesis

Autonomic nerves control organ function through the sympathetic and parasympathetic branches, which have opposite effects. In the bone marrow, sympathetic (adrenergic) nerves promote hematopoiesis; however, how parasympathetic (cholinergic) signals modulate hematopoiesis is unclear. Here, we show that B lymphocytes are an important source of acetylcholine, a neurotransmitter of the parasympathetic nervous system, which reduced hematopoiesis. Single-cell RNA sequencing identified nine clusters of cells that expressed the cholinergic α7 nicotinic receptor (Chrna7) in the bone marrow stem cell niche, including endothelial and mesenchymal stromal cells (MSCs). Deletion of B cell-derived acetylcholine resulted in the differential expression of various genes, including Cxcl12 in leptin receptor+ (LepR+) stromal cells. Pharmacologic inhibition of acetylcholine signaling increased the systemic supply of inflammatory myeloid cells in mice and humans with cardiovascular disease.

Prothymosin Alpha: A Novel Contributor to Estradiol Receptor Alpha-Mediated CD8+ T-Cell Pathogenic Responses and Recognition of Type 1 Collagen in Rheumatic Heart Valve Disease

BACKGROUND

Rheumatic heart valve disease (RHVD) is a leading cause of cardiovascular death in low- and middle-income countries and affects predominantly women. The underlying mechanisms of chronic valvular damage remain unexplored and regulators of sex predisposition are unknown.

METHODS

Proteomics analysis of human heart valves (nondiseased aortic valves, nondiseased mitral valves [NDMVs], valves from patients with rheumatic aortic valve disease, and valves from patients with rheumatic mitral valve disease; n=30) followed by system biology analysis identified ProTα (prothymosin alpha) as a protein associated with RHVD. Histology, multiparameter flow cytometry, and enzyme-linked immunosorbent assay confirmed the expression of ProTα. In vitro experiments using peripheral mononuclear cells and valvular interstitial cells were performed using multiparameter flow cytometry and quantitative polymerase chain reaction. In silico analysis of the RHVD and Streptococcuspyogenes proteomes were used to identify mimic epitopes.

RESULTS

A comparison of NDMV and nondiseased aortic valve proteomes established the baseline differences between nondiseased aortic and mitral valves. Thirteen unique proteins were enriched in NDMVs. Comparison of NDMVs versus valves from patients with rheumatic mitral valve disease and nondiseased aortic valves versus valves from patients with rheumatic aortic valve disease identified 213 proteins enriched in rheumatic valves. The expression of the 13 NDMV-enriched proteins was evaluated across the 213 proteins enriched in diseased valves, resulting in the discovery of ProTα common to valves from patients with rheumatic mitral valve disease and valves from patients with rheumatic aortic valve disease. ProTα plasma levels were significantly higher in patients with RHVD than in healthy individuals. Immunoreactive ProTα colocalized with CD8⁺ T cells in RHVD. Expression of ProTα and estrogen receptor alpha correlated strongly in circulating CD8⁺ T cells from patients with RHVD. Recombinant ProTα induced expression of the lytic proteins perforin and granzyme B by CD8⁺ T cells as well as higher estrogen receptor alpha expression. In addition, recombinant ProTα increased human leukocyte antigen class I levels in valvular interstitial cells. Treatment of CD8⁺ T cells with specific estrogen receptor alpha antagonist reduced the cytotoxic potential promoted by ProTα. In silico analysis of RHVD and Spyogenes proteomes revealed molecular mimicry between human type 1 collagen epitope and bacterial collagen-like protein, which induced CD8⁺ T-cell activation in vitro.

CONCLUSIONS

ProTα-dependent CD8⁺ T-cell cytotoxicity was associated with estrogen receptor alpha activity, implicating ProTα as a potential regulator of sex predisposition in RHVD. ProTα facilitated recognition of type 1 collagen mimic epitopes by CD8⁺ T cells, suggesting mechanisms provoking autoimmunity.

Abstract WP229: Eicosapentaenoic Acid (EPA) Modulates Expression Of Thrombotic And Metabolic Proteins In Brain Endothelium Following Cytokine Challenge

Background: During inflammation, vascular endothelial cells (ECs) release vasoconstrictive and thrombotic factors that promote abnormal blood flow and atherothrombosis. The omega-3 fatty acid (n3FA) eicosapentaenoic acid (EPA) reduced first and total ischemic strokes each by 36% in patients with elevated cardiovascular risk (REDUCE-IT) when administered as icosapent ethyl. We measured the effects of EPA on expression of proteins involved in cytoprotection, thrombosis, and fatty acid metabolism in human brain ECs subjected to inflammation.

Methods: Human brain microvascular ECs (HBECs) were first challenged with IL-6 at 12 ng/ml for 2 hr and then treated with EPA (40 μM) for 24 hr. Global proteomic analysis was performed using LC/MS to measure relative expression levels of >1,000 proteins simultaneously. Only significant (p<0.05) changes in expression between treatment groups >1-fold were analyzed.

Results: EPA treatment significantly modulated the expression of 504 proteins (212 increased expression, 292 decreased expression) in HBECs compared with IL-6 alone. EPA treatment increased expression of the cytoprotective enzyme heme oxygenase-1 by 1.5-fold (p = 4.7 х 10 -16 ) relative to IL-6 alone. Additionally, IL-6 increased expression of prothrombin (clotting factor II) 1.3-fold relative to control (p = 1.41 х 10 -20 ), and EPA decreased expression of prothrombin by 1.3-fold relative to IL-6 (p = 2.10 х 10 -24 ). EPA also reduced expression of fatty acid desaturase 1 & 2 by 1.4-fold and 2.6-fold, respectively, which may lead to changes in intracellular fatty acid levels.

Conclusions: EPA significantly modulated expression of cytoprotective, thrombotic, and metabolic proteins in brain ECs under conditions of inflammation with IL-6. These effects of EPA on inflammation have implications for ischemic disease, including stoke, as demonstrated in large outcome trials.

Abstract WP210: Eicosapentaenoic Acid (EPA) Decreases Cytokine Release And Inflammatory Proteins In Brain Vascular Endothelium During Inflammation

Background: Brain vascular endothelial cell (EC) dysfunction is characterized by release of pro-inflammatory mediators that contribute to atherosclerosis and ischemic stroke. Treatment with icosapent ethyl (IPE), the ethyl ester of the omega-3 fatty acid, eicosapentaenoic acid (EPA), reduced first and total ischemic strokes each by 36%, without increasing hemorrhagic stroke, in statin-treated patients with elevated cardiovascular risk (REDUCE-IT). We tested the effects of EPA on cytokine release and expression of inflammatory proteins from brain microvascular ECs during inflammation.

Methods: Human brain microvascular endothelial cells (HBECs) were pretreated with the cytokine IL-6 at 12 ng/ml for 2 h before treatment with EPA (40 μM) for 24 h. Proteomic analysis was performed using LC/MS to capture relative expression levels. Only significant changes in protein expression between treatment groups >1-fold were analyzed. Gene set enrichment analysis was also performed on all significantly regulated proteins to identify groups of proteins (pathways) that were affected. Levels of soluble intercellular adhesion molecule-1 (sICAM-1) and tumor necrosis factor-α (TNF-α) were measured by immunochemistry (ELISA).

Results: IL-6 exposure produced increased levels of sICAM-1 and TNF-α by 102% and 147% (p<0.001), respectively, in brain ECs compared with vehicle. EPA treatment reduced release of sICAM-1 by 43% (p<0.001) and TNF-α by 52% (p<0.001) compared to IL-6 alone. EPA also downregulated 43 proteins involved in the “neutrophil degranulation” pathway in brain ECs (p-adjusted = 2.63 х 10 -12 ), including heat shock protein 90-alpha and beta by 1.1-fold each relative to IL-6 alone.

Conclusions: In brain vascular ECs, EPA significantly reduced expression of pro-inflammatory mediators and proteins associated with neutrophil degranulation under inflammatory conditions. The ability of EPA to reverse brain EC dysfunction during inflammatory may contribute to reductions in stroke risk.

The dawn of a new era of targeted lipid-lowering therapies

Lipid risk factors for cardiovascular disease depend in part on lifestyle, but optimum control of lipids often demands additional measures. Low-density lipoprotein (LDL) doubtless contributes causally to atherosclerosis. Recent human genetic findings have substantiated a number of novel targets for lipid-lowering therapy including apolipoprotein C-III, angiopoietin-like protein 3 and 4, apolipoprotein V, and ATP citrate lyase. These discoveries coupled with advances in biotechnology development afford new avenues for management of LDL and other aspects of lipid risk. Beyond LDL, new treatments targeting triglyceride-rich lipoproteins and lipoprotein(a) have become available and have entered clinical development. Biological and RNA-directed agents have joined traditional small-molecule approaches, which themselves have undergone considerable refinement. Innovative targeting strategies have increased efficacy of some of these novel interventions and markedly improved their tolerability. Gene-editing approaches have appeared on the horizon of lipid management. This article reviews this progress offering insight into novel biological and therapeutic discoveries, and places them into a practical patient care perspective.

Increased prevalence of clonal hematopoiesis of indeterminate potential amongst people living with HIV

People living with human immunodeficiency virus (PLWH) have significantly increased risk for cardiovascular disease in part due to inflammation and immune dysregulation. Clonal hematopoiesis of indeterminate potential (CHIP), the age-related acquisition and expansion of hematopoietic stem cells due to leukemogenic driver mutations, increases risk for both hematologic malignancy and coronary artery disease (CAD). Since increased inflammation is hypothesized to be both a cause and consequence of CHIP, we hypothesized that PLWH have a greater prevalence of CHIP. We searched for CHIP in multi-ethnic cases from the Swiss HIV Cohort Study (SHCS, n = 600) and controls from the Atherosclerosis Risk in the Communities study (ARIC, n = 8111) from blood DNA-derived exome sequences. We observed that HIV is associated with a twofold increase in CHIP prevalence, both in the whole study population and in a subset of 230 cases and 1002 matched controls selected by propensity matching to control for demographic imbalances (SHCS 7%, ARIC 3%, p = 0.005). We also observed that ASXL1 is the most commonly mutated CHIP-associated gene in PLWH. Our results suggest that CHIP may contribute to the excess cardiovascular risk observed in PLWH.