Atherosclerosis

BackgroundLipoprotein(a) [Lp(a)] is a causal risk factor for cardiovascular disease (CVD), with plasma concentrations higher in Black individuals than in White individuals. Published findings support a model in which high Lp(a), in part through oxidized phospholipid (oxPL)-mediated signaling, promotes a pro-inflammatory monocyte phenotype that may contribute to arterial wall inflammation and the development of CVD. Here, we examined the relationship between Lp(a) concentrations and isoform size and the distribution of circulating monocyte populations in Black and White individuals using single-cell RNA sequencing (scRNA-seq) data. MethodsUsing standardized assays, we measured plasma Lp(a) levels, isoform size, inflammatory markers, and oxidized phospholipids in stored plasma samples from our previously published cohort of 128 participants. After excluding smokers and individuals with type II diabetes, a total of 34 participants (20 Black participants, 14 White participants) were included in analyses. Participants were further stratified by plasma Lp(a) levels into normal Lp(a) [median 12.6 nmol/L, with 15 individuals (8 Black participants) and high Lp(a) (median 159 nmol/L, with 19 individuals (12 Black partcipants)]. Multivariable linear regression was used to assess the association between plasma Lp(a) levels, Lp(a)-oxPL, and the proportion of monocyte subsets. Across all participants, scRNA-seq data identified six classical monocyte subsets, one non-classical monocyte subset, one MHCIIhi monocyte subset, and one interferon (IFN)-responsive monocyte subset. ResultsThe distribution of monocyte subsets was similar in individuals with normal versus high Lp(a) levels. Despite the small study cohort, self resported race modified the assocation between plasma Lp(a) levels and the proportion of non-classical monocytes (P = 0.032), which was inversely associated in White participants (P = 0.028), but not in Black partcipatns (P = 0.470). OxPL bound to APO(a) showed a positive correlation with plasma Lp(a) levels (R2 = 0.84; P = 3.3x10-14), and non-classical monocytes (PWhites = 0.027; PBlacks = 0.275; PInteraction = 0.014). Race also modified the association between plasma Lp(a) levels and the proportion of classical 2 monocytes (P = 0.027). ConclusionsThese results underscore the importance of self reported race when analysing studies on Lp(a), monocytes and, cardiovascular related monocyte immune functions.

IntroductionsAortic dissection (AD) is a life-threatening vascular disease with limited therapeutic targets. Apolipoprotein H (APOH), a circulating glycoprotein implicated in lipid metabolism, has not been studied in AD. MethodsPlasma APOH levels and aortic deposition were examined in AD patients. A {beta}-aminopropionitrile (BAPN) and angiotensin II (Ang-II)-induced mouse AD model with AAV-mediated Apoh knockdown was used to evaluate survival, aortic dilation, and extracellular matrix remodeling. Transcriptomic profiling, chromatin immunoprecipitation, and gene silencing in human aortic vascular smooth muscle cells (HAVSMC) were performed to dissect the mechanism. PPAR{gamma} agonist rescue was conducted in vivo. ResultsAPOH was elevated in plasma and deposited in AD aortas. Apoh knockdown improved survival, reduced AD incidence and ascending aortic dilation, and attenuated elastic fiber disruption and collagen deposition. Transcriptomics revealed enrichment of the PPAR pathway. APOH promoted HAVSMC phenotypic switching from a contractile to a synthetic state, decreasing ACTA2/TAGLN and increasing OPN/MMP9. Mechanistically, APOH upregulated NR5A1, which directly bound the PPAR{gamma} promoter to enhance PPAR{gamma} and FABP4 expression. Silencing NR5A1 or PPAR{gamma} reversed APOH-induced phenotypic switching and inflammation. In vivo, PPAR{gamma} agonist diminished the protective effects of Apoh silencing. ConclusionAPOH promotes AD progression through the NR5A1-PPAR{gamma} axis, driving vascular smooth muscle cell phenotypic switching and inflammation, and represents a potential therapeutic target. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=142 SRC="FIGDIR/small/739043v1_ufig1.gif" ALT="Figure 1"> View larger version (64K): org.highwire.dtl.DTLVardef@323110org.highwire.dtl.DTLVardef@133260dorg.highwire.dtl.DTLVardef@1075c9eorg.highwire.dtl.DTLVardef@51a965_HPS_FORMAT_FIGEXP M_FIG C_FIG Circulating APOH promotes aortic dissection through the NR5A1-PPAR{gamma} axis in human aortic vascular smooth muscle cells. Clinical observations showed that plasma APOH levels were elevated in patients with aortic dissection. Circulating APOH acts on human aortic vascular smooth muscle cells (HAVSMC) and upregulates NR5A1, which binds to the PPARG promoter and enhances PPAR{gamma} transcription. Activation of the NR5A1-PPAR{gamma} signaling axis promotes the phenotypic transition of HAVSMCs from a contractile phenotype to a synthetic phenotype, as indicated by decreased ACTA2 and TAGLN expression and increased OPN and MMP9 expression, accompanied by enhanced production of the inflammatory mediators IL-6, MCP-1, and TNF-. Silencing NR5A1 or PPAR{gamma} reverses APOH-induced phenotypic switching and inflammatory responses, supporting the critical role of the NR5A1-PPAR{gamma} axis in APOH-mediated vascular injury.

Aims: Despite similar LDL-C levels, size and composition of LDL particles (LDL-P) varies widely. Among the metabolically perturbed, or those with altered function of lipid regulatory proteins, LDL-C levels mask elevated atherogenic small-medium LDL-P (S/M LDL-P). We assessed the contribution of such discordance in S/M LDL-P on major adverse cardiovascular event risk (MACE). Methods and results: UK Biobank participants with Nightingale NMR metabolomics (487,521 participants), were classified as high or low cardiometabolic burden. S/M LDL-P discordance was defined as the difference between LDL-C predicted S/M LDL-P and observed S/M LDL-P. Genetic variants encoding cholesterol ester transfer protein (CETP), which regulates cholesterol-triglyceride exchange and the production of small LDL particles, were identified via whole genome sequencing. Adjusted Cox proportional hazard regression was used to estimate MACE associations. S/M LDL-P discordance showed an LDL-C and Apo-B independent association with MACE (47,935 cases), which differed by cardiometabolic burden group: hazard ratio (HR) per standard deviation 1.09 (95%CI 1.05; 1.13) and HR 1.24 (95%CI 1.21; 1.27) for low/high burden, respectively. Loss of function (LoF) CETP variants were strongly associated with lower levels of both S/M LDL-P and S/M LDL-P discordance. For example, the S/M LDL-P discordance effect of CETP LoF carriership for low/high metabolic burden, respectively, was -4.62 nmol/L (95%CI -8.40; -0.83) compared to -11.10 nmol/L (95%CI -15.57; -6.63). Conclusion: S/M LDL-P discordance (overabundance) is strongly associated with MACE risk, especially in people with high cardiometabolic burden. S/M LDL-P discordance is modified by CETP genetic variation, suggesting a role for CETP-mediated lipid remodelling beyond LDL-C changes.

Atherosclerosis is a chronic inflammatory condition of the arteries leading to myocardial infarction, ischemic stroke and peripheral arterial diseases. Atherosclerotic plaques, which obstruct blood flow contain functionally diverse macrophage populations including pro-atherogenic and atheroprotective subsets. Aging is a major risk factor of atherosclerosis, but the mechanism underlying aging associated risk of atherosclerosis is unclear. Here, using integrated single-cell RNA sequencing data analysis, we demonstrate that specific monocyte and macrophage subsets are enriched in atherosclerotic plaques and the aging aorta of mice. We also show that Cd74 and MHCII genes such as H2-Aa, H2-Ab1, H2-Eb1, and H2-DMb1 are consistently upregulated in the monocytes and macrophages from atherosclerotic plaques, the aging aorta, and the aging bone marrow of mice. Our experimental data also show increased expression of CD74 surface protein by aortic macrophages and bone marrow monocytes from aged mice. In addition, we show increased CD74 expression by RAW264.7 mouse macrophages and THP1 human monocytes following ox-LDL stimulation in vitro. Finally, we demonstrate that monocytes from aged mice adhere more to aortic endothelial cells in co-cultures. Thus, increased monocyte adhesion to endothelial cells may explain the enhanced proportion of specific monocyte and macrophage subsets in the aging aorta, inducing a pre-atherosclerotic condition.

Background: Stability of the atherosclerotic plaque in coronary artery disease (CAD) is determined by features such as total plaque burden and necrotic core volume. Since invasive procedures are required to evaluate plaque stability, we tested whether the peripheral blood mononuclear cell (PBMC) microRNA (miR) signature could correlate with measures of plaque stability and thus serve as a non-invasive biomarker. Method: Patients from two distinct geographical locations in India were recruited to the study (Site 1: CAD=19, non-CAD=5; Site 2: CAD=12, non-CAD=7) and underwent invasive intravascular ultrasound with virtual histology to assess plaque burden and necrotic core volume. RNA from PBMCs of these patients was subjected to unbiased sequencing. Differential miR expression evaluated by DESeq2 and assessed for co-relationship with plaque stability. miR target gene prediction was performed using multiple databases, and Enrichr was used for enrichment analysis. Results: Unbiased RNA sequencing identified miR-664a-3p to be significantly downregulated in CAD patients from both sites (Site 1: log2FC=-1.02, p=0.0033 & Site 2: log2FC=-1.04, p=0.0007). miR-664a-3p expression was inversely correlated with plaque burden and necrotic core volume. Receiver operating characteristic (ROC) analysis of miR-664a-3p showed significant discriminative performance in the CAD cohort, with AUC values of 0.842 (Site 1) and 0.881 (Site 2). miR664a-3p target prediction and pathway enrichment analysis revealed selective enrichment of inflammatory signaling pathways, such as IL-17 and TNF, suggesting an association between PBMC pro-inflammatory response and plaque vulnerability. Conclusion: miR-664a-3p is downregulated in CAD patients and inversely correlates with measures of plaque stability, with potential as a biomarker for identifying patients at risk of CAD progression and plaque instability. Keywords: Coronary artery disease, peripheral blood mononuclear cells (PBMCs), microRNA, atherosclerotic plaque, necrotic core, plaque burden, biomarkers.

BackgroundOverweight and obese individuals often exhibit lower mortality rates or better prognoses than lean or normal-weight individuals with stroke and other diseases, a phenomenon called the "obesity paradox". Carotid atherosclerosis is the primary cause of ischemic stroke, and body weight serves as a reliable surrogate for adiposity in mice. MethodsPhenotypic and genetic connections of carotid atherosclerosis with body weight were evaluated in 299 F2 mice derived from BALB/cJ and LP/J Apoe knockout (Apoe-/-) mice. F2 mice were fed a Western diet for 12 weeks. Atherosclerotic lesion sizes in left carotid arteries, body weight, coat color, plasma lipids, glucose, small dense LDL ApoB, and malondialdehyde were measured, and 11,000 single nucleotide polymorphism (SNP) markers were genotyped. ResultsCarotid lesion sizes inversely correlated with body weight in both sexes. Genome-wide scans identified two significant quantitative trait loci (QTLs) for carotid atherosclerosis on chromosomes (Chr) 6 and 15 in an additive sex model, and five QTLs on Chr 6, 7, 12, 13, and 15 in an interactive sex model. Adjusting for body weight variation downgraded Chr 15 QTL (Cath5) in both models, whereas other QTLs upgraded in the additive sex model and downgraded in the interactive sex model. Human syntenic region of Cath5 associated with carotid intima-medial thickness (cIMT) and waist-to-hip ratio (WHR). ConclusionsThese findings indicate that the obesity paradox in carotid atherosclerosis is partially driven by shared genetic components that exert opposing effects on adiposity and plaque development and act through sex-dependent mechanisms.

Background: Phenotyping of atherosclerotic plaque vulnerability has largely relied on histopathology that captures structural features, but does not fully account for clinical presentation. Proteomic profiling could uncover molecular readouts of vulnerability that refine plaque phenotyping and provide mechanistic insights. Yet, the proteomic signatures associated with plaque rupture and symptomatic presentation are poorly characterized. Methods: We profiled paired carotid plaque tissue and preoperative plasma from 88 patients undergoing carotid endarterectomy (51 symptomatic, 37 asymptomatic) using the Olink Explore 3072 platform. We related plaque protein abundance to symptomatic presentation and quantitative histopathological features, and compared the performance of histopathology- vs. proteomics-based models for discriminating symptomatic disease. Next, we developed proteomic signatures of cellular abundance and explored their associations with plaque phenotypes by using plaque single-cell RNA-sequencing (scRNA-seq) data. Finally, we assessed plaque-plasma concordance across 2,837 shared proteins. Results: Across 2,837 plaque proteins, 19 were differentially expressed in symptomatic plaques related to distinct clinical events, highlighting pathways related to neutrophil degranulation and innate immune system. FGFBP1 showed the strongest association with symptomatic presentation (log2 fold change = 1.14; P = 1.82 x 10^-6). Proteins associated with a composite vulnerability index based on histopathology were enriched for inflammatory pathways, including TNF signaling through NF{kappa}B, complement activation, and IL6-JAK-STAT3 signaling. Individual proteins also mapped to specific histopathological features, including CXCL8 associated with macrophage burden and lipid core size, and EPHB4 and PKN3 with neovascularization. A proteomics-based model discriminated symptomatic from asymptomatic plaques substantially better than a histopathology-based model (AUC 0.83 vs. 0.66; P = 0.026). Integration with scRNA-seq data enabled the development of cell-class signatures that correlated with histopathology readouts, including macrophage burden, smooth muscle cell content, and neovascularization. Plaque and plasma protein levels showed limited overall correspondence (median {rho}=0.11), although selected proteins, including FGFBP1, demonstrated concordant associations in plasma. Conclusions: Deep proteomic profiling of human carotid plaques identifies molecular signatures of symptomatic atherosclerosis that extend beyond conventional histopathology. These signatures implicate neutrophil activation and inflammatory signaling pathways as key determinants of plaque vulnerability. Although plaque and plasma proteomes are largely distinct, selected proteins may represent promising circulating biomarkers for future risk stratification.

Background: Familial hypercholesterolemia (FH) is a semi-dominant genetic disorder characterized by lifelong elevation of low-density lipoprotein cholesterol (LDL-C) and a markedly increased risk of premature atherosclerotic cardiovascular disease (CVD). Despite this elevated risk, some individuals with FH survive beyond 70 years of age without developing clinical CVD. This study aimed to identify genetic variants associated with protection against cardiovascular events and to uncover mechanisms contributing to this resilience phenotype. Methods: Whole-exome sequencing (WES) was performed in 243 French-Canadian heterozygous FH individuals carrying the pathogenic LDLR c.259T>G (p.Trp87Gly) variant. After stratification by age and cardiovascular event (CVE) status, 35 individuals with premature CVE and 20 individuals aged [≥]70 years who remained free of CVE despite spending several decades in the pre-statin era were selected for comparative analysis. Results: Variant annotation and quality-control validation using Firth logistic regression identified 12 genetic variants potentially associated with cardiovascular resilience. Among these, a stop-gain variant resulting from the single-nucleotide polymorphism rs4985556 in IL34 demonstrated the strongest association with event-free survival (allele frequency in CVE- = 0.25 vs. CVE+ = 0.00; {chi}2 = 19.25; P = 1.15 x 10-5). The IL34 stop-gain variant (c.639C>A [p.Tyr213*]) was associated with a markedly increased likelihood of cardiovascular event-free survival (OR = 20.9; 95% CI, 2.7-2841.7; P = 3.45 x 10-4). Conclusion: These findings identify IL34 as a potential cardiovascular resilience gene and highlight novel genetic determinants that may protect against cardiovascular events despite lifelong exposure to elevated LDL-C levels. In addition to IL34, eleven variants showed strong associations with a CVE-free phenotype and warrant further investigation to elucidate their biological mechanisms and potential relevance for cardiovascular disease prevention.

BackgroundWe previously performed a strain intercross between atherosclerosis resistant AKR Apoe-/-mice and atherosclerosis sensitive DBA/2 Apoe-/- mice and identified the Ath28 quantitative trait locus (QTL) on the distal end of chromosome 2. Congenic strain fine mapping identified the Ath28.1 QTL atherosclerosis modifying subregion, encompassing 217 Kb, containing for only three protein-coding genes, Zbp1, Pck1, and Pmepa1, encoding respectively, Z-DNA binding protein 1, phosphoenolpyruvate carboxykinase 1, and prostate transmembrane protein androgen induced 1. MethodsThe effect of macrophage-specific knockout of Pck1 (KO) was tested using the AAV2 transduced proprotein convertase subtilisin kexin type 9 (PCSK9) overexpression mouse model of hyperlipidemia and atherosclerosis. ResultsUnexpectedly, macrophage Pck1 deficiency lowered body weight, liver weight, and HDL-cholesterol levels in both sexes, while total and non-HDL cholesterol levels were only decreased in male mice. Aortic root lesion area and necrotic lesion area were unchanged in KO mice of both sexes. ConclusionPck1 was not confirmed as an atherosclerosis modifier gene.

DNA methylation is a key epigenetic mechanism regulating the expression of genes involved in numerous developmental and pathological processes. However, the contribution of DNA methylation of microRNA genes to atherosclerosis remains poorly understood. In this study, we profiled DNA methylation patterns of both the regulatory elements and gene bodies of five microRNA genes (MIR10B, MIR21, MIR100, MIR127, and MIR143) in vascular tissues and paired peripheral blood cells (PBC) of 92 patients with advanced carotid atherosclerosis and 32 PBC of control participants by targeted bisulfite sequencing. We identified distinct tissue-specific DNA methylation patterns for all five microRNA genes in patients with advanced carotid atherosclerosis. The regulatory regions of MIR10B, MIR127, and MIR100 were moderately hypomethylated in carotid atherosclerotic plaques compared with intact vascular tissues. We further integrated our findings with lab-internal and publicly available epigenome-wide methylation datasets and evaluated the influence of vascular and blood cell composition using computational deconvolution approaches. After adjustment for cellular heterogeneity in vascular tissues, DNA methylation at CpG sites in MIR100 and MIR127 remained independently associated with atherosclerosis. Increased DNA methylation at a single CpG site (chr11:122025143, GRCh37/hg19) located within the MIR100 E-box region was associated with metabolic syndrome. Moreover, DNA methylation levels of MIR10B, MIR21, and MIR127 in atherosclerotic plaques were linked with indicators of histological instability and history of acute cerebrovascular events. In peripheral blood, we observed moderate hypomethylation of the regulatory regions of MIR10B, MIR21, and the MIR100 E-box region in patients compared with the control group. However, only the MIR10B remained robust against blood cell composition. In blood, MIR10B and MIR143 methylation correlated with lipid metabolism and carotid stenosis, while the MIR21 CpG island showed strong blood-plaque concordance, confirming its potential as a surrogate biomarker. Overall, advanced carotid atherosclerosis is characterized by specific tissue-altering DNA methylation patterns of microRNA genes, where alterations mainly occur in the regulatory regions, predominantly featuring hypomethylation. The results underscore the complex, cell- and tissue-specific nature of DNA methylation of microRNA genes in both the regulatory elements and gene bodies in vascular tissue and blood, highlighting the critical need to decipher these intricate epigenetic landscapes to identify reliable, robust biomarkers for assessing plaque instability and cardiovascular risk.

Background Carotid plaque calcification is commonly interpreted as a marker of atherosclerotic burden, but its prognostic meaning may depend on calcification morphology. Whether histologically defined calcification subtypes in carotid plaques identify systemic cardiovascular disease and long-term cardiac risk remains unclear. Methods We studied 479 patients, including 154 women, undergoing carotid endarterectomy in the Helsinki Carotid Endarterectomy Study 2 with 10-year follow-up. Hematoxylin-eosin-stained plaque sections were digitized, and artificial intelligence-based image analysis was used to quantify sheet, nodular, and total calcification as proportions of plaque tissue area. The primary endpoint was cardiac death; secondary endpoints were major coronary events and major adverse limb events (MALE). Associations between calcification tertiles and outcomes were assessed using Fine-Gray regression models adjusted for conventional cardiovascular risk factors, with prespecified sex-stratified analyses. Results Total calcification was associated with baseline coronary artery disease and chronic heart failure but did not predict cardiac mortality. In contrast, nodular calcification was independently associated with cardiac death. Compared with the lowest tertile, the middle and highest tertiles of nodular calcification were associated with increased cardiac mortality in the whole cohort (subdistribution hazard ratio [sHR], 2.87 [95% CI, 1.39-5.91] and 2.55 [95% CI, 1.24-5.27], respectively). Nodular calcification was also associated with baseline peripheral artery disease. High sheet calcification was associated with cardiac death in men (sHR, 2.3 [95% CI, 1.0-5.1]) but not in women. Exploratory sex-stratified analyses suggested that high total calcification was associated with major coronary events and MALE in women, but not in men. Conclusions Carotid plaque calcification morphology, rather than total calcification burden alone, is associated with long-term cardiac mortality after carotid endarterectomy. Nodular calcification emerged as the strongest prognostic phenotype, while exploratory sex-stratified findings suggest that total calcification may reflect coronary and peripheral event risk in women.

Background: Preoperative risk assessment in vascular surgery relies on clinical scores and lipids that do not capture atherosclerotic disease activity. Circulating fatty acid synthase (cFAS) is a liver-derived enzyme whose concentration correlates with arterial plaque FAS content independent of LDL. The 5-item modified frailty index (mFI-5) is a validated predictor of postoperative mortality. Whether cFAS predicts outcomes after vascular surgery, and whether combining it with the mFI-5 improves risk discrimination, have not been examined. Methods: We studied 657 patients undergoing elective vascular surgery at a single center (2014 to 2023). cFAS was classified as non-detectable (n = 306) or, among detectable values, by tertiles (n = 117 each). Multivariable Cox models assessed associations with major adverse events (MAE), major adverse cardiovascular events (MACE), major adverse limb events (MALE), reintervention, and mortality, and Harrell's C-statistic quantified the incremental discrimination gained by adding cFAS and the mFI-5 to standard clinical covariates. Results: High serum cFAS was independently associated with 5-year MAE (adjusted hazard ratio [aHR] 1.94; 95% CI 1.31- 2.85), mortality (aHR 1.77; 1.05 to 3.00), MALE (aHR 4.53; 2.04 to 10.05), and reintervention (aHR 2.50; 1.37 to 4.57), but not MACE. Severe frailty (mFI-5 of 3 or higher) was associated with MACE (aHR 2.69; 1.29 to 5.58) and MAE (aHR 2.46; 1.30 to 4.65) but not limb endpoints at 1 year. Adding cFAS raised the 1-year MALE C-statistic from 0.649 to 0.764; the combined model yielded the highest discrimination. Conclusions: cFAS and mFI-5 were independently and additively associated with adverse outcomes after elective vascular surgery. cFAS was associated with limb events and mortality, the mFI-5 with cardiovascular events. Combining them improved discrimination over standard covariates.

Background Despite available lipid-lowering therapies (LLT), many patients fail to achieve low-density lipoprotein cholesterol (LDL-C) targets. This gap persists across clinically relevant subgroups. Bempedoic acid has demonstrated effective LDL-C lowering with a favorable safety profile in the CLEAR Taiwan study; however, its effects across subgroups in Asian populations remains limited. Methods The phase IV CLEAR Taiwan study (NCT06925100) enrolled patients with inadequately controlled hypercholesterolemia who received bempedoic acid for 12 weeks in addition to background LLT. This analysis evaluated changes in lipid parameters, high-sensitivity C-reactive protein (hsCRP), and safety outcomes in clinically relevant subgroups, including cardiovascular risk, diabetes, age, statin tolerance, and sex. Results A total of 180 patients were included. Bempedoic acid achieved significant LDL-C reductions in all subgroups. Numerically greater LDL-C reductions were observed in primary prevention, statin-intolerant, younger (< 65 years), and female patients, while comparable reductions were observed across diabetes status. Reductions in non-high-density lipoprotein cholesterol, total cholesterol, and apolipoprotein B were consistent with LDL-C findings. Significant decreases in hsCRP were observed in all subgroups, with numerically greater reductions in patients aged < 65 years and those without diabetes. Bempedoic acid was well tolerated, with a low incidence of adverse events and no new safety signals identified. Changes in liver enzymes, renal function, and uric acid were minimal within subgroups. Conclusion Subgroup analyses from the CLEAR Taiwan study demonstrate consistent efficacy and safety of bempedoic acid across clinically relevant subgroups and support its use as a flexible option to address residual gaps in lipid management.

Background: Elevated low-density lipoprotein cholesterol (LDL-C) is a causal risk factor for atherosclerotic cardiovascular disease (ASCVD). Guidelines recommend reducing saturated fat intake to lower LDL-C. However, LDL-C responses to saturated fat vary substantially from person to person. Genetic factors may contribute to individual differences in response to saturated fat. Objectives: We aimed to examine whether genetic propensity for higher LDL-C modifies the association of saturated fat intake with LDL-C and incident ASCVD. Methods: We studied 20,940 genotyped postmenopausal women from the Women's Health Initiative. Exposures included saturated fat intake (percentage of total calories) derived from food frequency questionnaires and a genome-wide polygenic score for LDL-C (PGS-LDL). The primary outcome was LDL-C. The secondary outcome was incident ASCVD. Associations were assessed using multivariable linear and Cox regressions. Effect modification was evaluated using interaction terms and restricted cubic spline analyses. Results: The median LDL-C at baseline for participants with PGS-LDL below and above the median was 135 mg/dL [Q1: 114, Q3: 160] and 162 mg/dL [137, 188], respectively. Saturated fat intake was positively associated with LDL-C in the high PGS-LDL group, but the association attenuated in the low PGS-LDL group (P-interaction=0.01). Spline analysis revealed a non-linear interaction between PGS-LDL and saturated fat, with modifying effects emerging at higher PGS-LDL. Compared to individuals with low PGS-LDL and low saturated fat intake, only those with both high PGS-LDL and high saturated fat intake had increased risk for ASCVD in an adjusted analysis (HR 1.30, 95% CI 1.13-1.51). This association remained significant after further adjustment for baseline LDL-C (HR 1.17, 95% CI 1.01-1.37). Spline analyses of ASCVD risk revealed a similar interaction pattern to that observed for LDL-C. Conclusions: These findings suggest that the association between saturated fat intake and LDL-C and subsequent ASCVD risk may be stronger for individuals with a genetic propensity towards high LDL-C.

Background: Spontaneous coronary artery dissection (SCAD) causes acute coronary syndrome that predominantly affects women. It is not known why SCAD occurs in specific coronary artery segments. We aimed to identify anatomical and hemodynamic factors that lead to SCAD. Methods: We studied 36 women with angiographically-confirmed SCAD from more than 20 hospital sites and 75 sex- and ethnicity-matched control participants with normal coronary anatomy. Coronary arteries were reconstructed from computed tomography coronary angiography (CTCA) to quantify vessel geometry (curvature, diameter, torsion) and flow-derived metrics (time-averaged endothelial shear stress [TAESS], topological shear variation index [TSVI], oscillatory shear index [OSI], and relative residence time [RRT]) at the tree (left/right), territory (LAD, LCx, RCA), and lesion levels. Results: Compared with controls, SCAD-affected coronary arteries had greater curvature and higher TAESS and TSVI at the whole-tree level (all p?0.007). At the vessel (territory) level, SCAD-affected arteries were smaller in average diameter and showed higher curvature, TAESS, and TSVI than matched control vessels (all p?0.047). Within the same patient, SCAD lesion segments were characterized by smaller diameter, lower torsion, and higher TAESS and TSVI than non-affected segments from the same coronary tree (all p?0.001; curvature borderline). A model combining curvature, TAESS, and TSVI discriminated SCAD from controls with AUC 0.95 (left tree) and 0.97 (right tree); adding diameter yielded AUCs >0.91 at the territory level. Conclusions: SCAD was associated with a reproducible multi-scale signature of smaller vessel caliber and higher, more variable endothelial shear stress supporting a hemodynamic contribution to SCAD clustering in specific coronary arteries and segments.

People living with HIV-1 (PWH) receiving antiretroviral therapy (ART) exhibit an increased cardiovascular disease (CVD) risk. Coronary atherosclerotic plaque formation is linked to chronic immune activation, a process fueled in PWH by additional mechanisms likely including residual HIV-1 production and microbial translocation from the gut during ART. Our previous studies demonstrated that aldehyde dehydrogenase (ALDH), an enzyme converting vitamin A into retinoic acid (RA), is upregulated in myeloid cells upon exposure to viral/bacterial/fungal products and that RA promotes HIV-1 production. To explore the link between ALDH/RA pathway and CVD risk, we used PBMC/plasma from ART-treated PWH (PWH+ART; n=51) and people without HIV-1 (Pw/oH; n=63) from the Canadian HIV/Aging Cohort Study, with/without subclinical coronary atherosclerosis, measured by coronary computed tomography angiography. ALDH expression was analyzed by flow cytometry on monocyte subsets, dendritic cells, and CD4+ T-cells. Unsupervised t-SNE-guided FlowSOM analysis associated top ALDH activity with a monocyte phenotype. The frequency of ALDH+ monocytes and plasma levels of RA and retinol binding protein 4 were increased in PWH+ART versus Pw/oH, with the highest RA levels coinciding with detectable plasma levels of soluble HIV-1 gp120. Multivariate regression models linked ALDH activity in monocytes to subclinical coronary atherosclerosis (i.e., total plaque volume, low attenuated plaque volume, coronary artery calcification score) presence/burden in PWH+ART, independently of Framingham risk score. Finally, ALDH+ monocyte frequency and RA levels positively correlated with pericoronary fat attenuation index, an emerging CVD predictor. Thus, ALDH/RA pathway may represent a new marker of metabolic/immune dysfunction contributing to CVD risk in ART-treated PWH.

Abdominal aortic aneurysms (AAAs) occur predominantly in the elderly population and currently there is no effective pharmacological therapy for mitigating AAA growth and preventing impending rupture. Proprotein subtilisin kexin type 9 (PCSK9) gene has been identified as a specific risk-locus for AAA development. However, the mechanistic and clinical role of PCSK9-mediated signaling in AAAs has not been delineated. We demonstrate that treatment with PCSK9 inhibitors, such as Evolocumab, mitigates vascular inflammation and remodeling, resulting in attenuated aneurysm growth in clinical datasets as well as experimental models of AAA and aortic rupture. Mechanistically, Evolocumab immunomodulates macrophage reprogramming to enhance clearance of apoptotic smooth muscle cells via MerTK-dependent efferocytosis that ameliorates aortic inflammation and vascular remodeling. Furthermore, Evolocumab increases the expression of oxidized phosphatidylserine species and decreases expression of lysophospholipids, succinate, and glycolytic intermediates within the aortic wall compared to untreated controls, further enhancing the pro-resolving functions of macrophages. Collectively, our data demonstrates the ability of PCSK9 inhibition to regulate macrophage-specific efferocytosis that limits AAA progression and prevents aortic rupture.

Background: Spontaneous cervical artery dissection (sCeAD) is a rare vasculopathy whose pathophysiology remains incompletely understood. Impaired vascular extracellular matrix integrity, including elastic fibers, may contribute to its development. We investigated whether serum fibrillin-1 and soluble elastin fragments (sELF) differ between patients with sCeAD and controls during the acute and chronic stages. Methods: Patients with acute sCeAD were prospectively enrolled at four German stroke centers. Blood samples were collected at baseline and after 6{+/-}1 months. Patients with a first acute ischemic stroke unrelated to sCeAD and healthy individuals served as controls. Serum fibrillin-1 and sELF concentrations were measured using enzyme-linked immunosorbent assays. Results: 61 patients with sCeAD, 53 patients with first non-CeAD ischemic stroke, and 79 healthy controls were included. After sex-matching, serum fibrillin-1 concentrations were significantly lower in patients with acute sCeAD than in healthy controls (97 [60; 192] vs. 176 [113; 269] ng/mL; p=0.009). Fibrillin-1 concentrations were also lower in both male and female patients with sCeAD than in respective healthy controls. In patients with sCeAD, fibrillin-1 concentrations increased significantly after 6 months compared with baseline (171 [130; 270] vs. 104 [67; 205] ng/mL; p=0.021). Serum fibrillin-1 concentrations were higher in men than in women across all study groups. No significant differences in sELF concentrations were observed between groups or time points. Discussion: Serum fibrillin-1 concentrations were lower during acute sCeAD and increased significantly during follow-up, whereas sELF concentrations remained unchanged. These findings support an association between circulating fibrillin-1 and acute sCeAD and warrant further investigation of its role in sCeAD pathophysiology. Pronounced sex-related differences in fibrillin-1 concentrations highlight the importance of sex-specific analyses in future.

Background and aims: Sex differences in ethnic minority risk of coronary heart disease (CHD) are often overlooked. Here we aim to explore sex-by-ethnicity differences in CHD outcomes and the contribution of risk factors. Methods: Incident CHD events were identified for Europeans, and South Asian and African/African Caribbean first generation migrants in the UK-based Southall and Brent Revisited (SABRE) cohort. Cardiovascular risk factors were assessed at baseline (1988-91). Cox proportional hazards models quantified group differences in CHD incidence and risk factor contribution. Population attributable fractions (PAFs) described risk factor contribution to group differences. Results: Among 4,754 participants followed for 40.8 years, 1,710 CHD first events occurred. Cumulative incidence of CHD was highest in South Asian males (65% by age 90) and females (55%), compared with 52% in European males and 24-31% in other groups. Sex differences in CHD incidence were pronounced in Europeans (female versus male HR=0.45, 95% CI [0.37,0.55]) but attenuated in South Asians (0.68 [0.56,0.82]) and African/African Caribbeans (0.79 [0.57,1.10]). CHD risk was higher in South Asian compared to European men (1.80 [1.63,1.99]). This ethnic difference was greater in females (2.44 [1.88,3.17]). PAFs for diabetes (PAF=18.0%, 95% CI [6.2,29.8]), hypercholesterolemia (44.2% [20.4,68.1]), and hypertriglyceridemia (22.4% [7.9,37.0]) made a greater contribution to the risk of CHD in South Asian females compared to all other groups. Conclusions: Ethnic minority female participants do not have the same protection from CHD as Europeans. Greater cardiometabolic burden may drive this elevated CHD risk and loss of female protection.

Abdominal aortic aneurysm (AAA) is a chronic inflammatory vascular disease characterized by progressive extracellular matrix degradation, vascular smooth muscle cell (VSMC) loss, and immune cell infiltration, ultimately leading to aortic dilation and rupture. Although vitamin 25(OH)D3 deficiency has been associated with cardiovascular inflammation, its mechanistic role in AAA pathogenesis remains poorly defined. Here, we investigated the role of vitamin D{square} mediated signaling to regulate complement pathway activation, particularly the C3a axis, to modulate aneurysm development. Single cell-RNA sequencing analysis of human tissue demonstrated significant differences in Vitamin D and complement pathway-related genes in VSMCs in AAAs compared to control aortic tissue. Using a murine elastase-induced AAA model, we observed that vitamin D3-deficient diet significantly enhances aortic dilation, leukocyte infiltration, proinflammatory cytokine expression and elastin fragmentation, as well as decreases SMC -actin expression compared with vitamin D3-sufficient conditions. Furthermore, vitamin D3 deficiency was accompanied by increased aortic expression of complement component C3a that correlated with vascular inflammation and remodeling during AAA progression. Pharmacological blockade with a C3a receptor antagonist (C3aRA) markedly attenuated AAA formation in two established murine AAA models with concomitant reductions in proinflammatory cytokines and preservation of aortic wall structure. In vitro studies demonstrated that stimulation of VSMCs significantly increased C3a production, which was suppressed by calcitriol (active form of Vitamin D) treatment. These studies suggest that the vitamin D-C3a axis is a critical regulator of vascular inflammation and AAA progression, and postulate that restoring vitamin D{square} sufficiency or targeting C3a signaling may represent a novel therapeutic strategy to limit AAA growth and rupture. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=162 SRC="FIGDIR/small/730431v1_ufig1.gif" ALT="Figure 1"> View larger version (36K): org.highwire.dtl.DTLVardef@18d5d8forg.highwire.dtl.DTLVardef@1f98952org.highwire.dtl.DTLVardef@1a66a95org.highwire.dtl.DTLVardef@9f6439_HPS_FORMAT_FIGEXP M_FIG C_FIG