Atherothrombotic Disease Research Articles

The Molecular Bases of Anti-Oxidative and Anti-Inflammatory Properties of Paraoxonase 1

The anti-oxidative and anti-inflammatory properties of high-density lipoprotein (HDL) are thought to be mediated by paraoxonase 1 (PON1), a calcium-dependent hydrolytic enzyme carried on a subfraction of HDL that also carries other anti-oxidative and anti-inflammatory proteins. In humans and mice, low PON1 activity is associated with elevated oxidized lipids and homocysteine (Hcy)-thiolactone, as well as proteins that are modified by these metabolites, which can cause oxidative stress and inflammation. PON1-dependent metabolic changes can lead to atherothrombotic cardiovascular disease, Alzheimer’s disease, and cancer. The molecular bases underlying these associations are not fully understood. Biochemical, proteomic, and metabolic studies have significantly expanded our understanding of the mechanisms by which low PON1 leads to disease and high PON1 is protective. The studies discussed in this review highlight the changes in gene expression affecting proteostasis as a cause of the pro-oxidative and pro-inflammatory phenotypes associated with attenuated PON1 activity. Accumulating evidence supports the conclusion that PON1 regulates the expression of anti-oxidative and anti-inflammatory proteins, and that the disruption of these processes leads to disease.

Optimal antithrombotic therapy in ischemic stroke patients with non-valvular atrial fibrillation and atherothrombosis: study protocol for a randomized controlled trial.

The addition of antiplatelet therapy to anticoagulant therapy in patients with stroke with non-valvular atrial fibrillation (NVAF) and atherothrombotic disease may increase bleeding risk without reducing recurrent stroke risk. To evaluate the clinical benefits of anticoagulant monotherapy compared to combination therapy with anticoagulants and antiplatelet agents. This is an investigator-initiated prospective multicenter, randomized, open-label, parallel-group clinical trial. Patients with NVAF and atherothrombotic disease who have had a recent ischemic stroke or transient ischemic attack will be eligible to participate in this trial. The primary outcome is a composite of ischemic cardiovascular events, including cardiovascular death, ischemic stroke, myocardial infarction, systemic embolism, ischemic events requiring urgent revascularization, and major bleeding events within 2 years after randomization. This study will enroll 400 patients, 200 receiving anticoagulant monotherapy and 200 receiving combination therapy. This sample size will provide 90% power (one-sided p = 0.025) to detect a risk reduction in outcome events within 2 years, assuming event rates of 13 and 27% for each group, respectively, and a 10% loss to follow-up at a 2.5% significance level with one-sided log-rank tests at an interim analysis and a final analysis. This will be the first study to assess the net clinical benefit of oral anticoagulant monotherapy in ischemic stroke patients with NVAF and atherothrombosis. https://clinicaltrials.gov/study/NCT03062319, NCT03062319; https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000029222, UMIN000025392; https://jrct.niph.go.jp/latest-detail/jRCTs051180202, jRCTs051180202.

Dyslipoproteinemias in postmenopausal women and new therapeutic targets

Dyslipoproteinemias play a very prominent role in the pathogenesis of atherosclerosis in postmenopausal women; These lose the cardiovascular protection of estrogens, increasing the risk of developing atherothrombotic vascular disease (CVD). International guidelines do not vary between the management of dyslipidemia between men and women, but these are treated less vigorously and without taking into account the postmenopausal hormonal situation. Its management must be included in the individual risk of each woman, with the new LDL goals and above all take into account Lipoproteins rich in Triglycerides (LPRTG) that are associated with the classic modifiable risk factors, in a non-modifiable biological terrain such as are age and genetic family history; which may be associated with emerging factors such as Lipoprotein “a” (Lp a), hyperhomocysteine, elevated CRP (C-reactive protein), among other factors that are rarely taken into account. Statins demonstrated their effectiveness in reducing LDL and even increasing HDL, reducing cardio and cerebrovascular events, but a good percentage of patients, despite the intensified doses, remain at Residual Lipid Risk, so we must resort to new therapeutic targets. like biological ones.

Small molecules targeting GRP78 mitigate anti-GRP78 autoantibody–mediated tissue factor procoagulant activity in cultured endothelial cells

BackgroundThe 78-kDa glucose-regulated protein (GRP78) expressed on the cell surface (csGRP78) has been reported to regulate tissue factor (TF) procoagulant activity (PCA) in lesion-resident endothelial cells (ECs), which is further enhanced by circulating anti-GRP78 autoantibodies that bind to the Leu98-Leu115 epitope in GRP78. ObjectivesDetermine the effects of the engagement of the anti-GRP78 autoantibody to csGRP78 on ECs and the underlying mechanisms that impact TF PCA. MethodsImmunofluorescent staining was used to determine the presence of csGRP78 in tumor necrosis factor α–treated ECs. An established TF PCA assay was used to evaluate human ECs following treatment with anti-GRP78 autoantibodies. The Fura 2-AM assay (Abcam) was used to quantify changes in intracellular Ca2+ levels. Small molecules predicted to bind GRP78 were identified using artificial intelligence. Enzyme-linked immunosorbent assays were used to assess the ability of these GRP78 binders to mitigate TF activity and interfere with the autoantibody/csGRP78 complex. ResultsIn tumor necrosis factor α–treated ECs, anti-GRP78 autoantibodies increased TF PCA. This observation was further enhanced by endoplasmic reticulum stress-induced elevation of csGRP78 levels. Anti-GRP78 autoantibody treatment increased intracellular Ca2+ levels. Sequestering the anti-GRP78 autoantibody with a conformational peptide or blocking with heparin attenuated anti-GRP78 autoantibody–induced TF PCA. We identified B07∗, as a GRP78 binder that diminished anti-GRP78 autoantibody–induced TF PCA on ECs. ConclusionThese findings show how anti-GRP78 autoantibodies enhance TF PCA that contributes to thrombosis and identify novel GRP78 binders that represent a potential novel therapeutic strategy for treating and managing atherothrombotic disease.

PCSK9 gene variations in the clinical setting of premature cardiovascular disease: A critical appraisal

IntroductionInformation about PCSK9 gene variations and its association with cardiovascular (CV) disease is controversial. We aimed to evaluate 3 reported polymorphisms in PSCK9 in a cohort of young patients with myocardial infarction with ST segment elevation (STEMI). MethodsRetrospective study of consecutive patients with premature STEMI (2018–2023). 216 patients with STEMI due atherothrombotic coronary artery disease (CAD), confirmed by coronary angiogram, were included. We genotyped 3 polymorphisms in PCSK9 (rs12117661, rs2483205, rs505151) in 207 patients (DNA unavailable in 9) and a control group (N = 200). ResultsMean age 49.4 ± 6,6 years (82.4% men). Genotypes frequencies distribution in patient's and control's cohorts did not deviate from the expected by Hardy-Weinberg equilibrium and there were no significant differences between patients and controls. Among patients, we did not find any association between PSCK9 genotypes and clinical variables (gender, age, CV risk factors, cholesterol levels, family history of premature CAD or number of coronary arteries affected). ConclusionWe did not find any association between PSCK9 genotypes (RS12117661, RS2483205 and RS505151) and any CV risk factors or the extent of CAD in a cohort of patients with premature STEMI. There were not differences in the genotype distribution between patients and controls.

P2Y12 Receptor Inhibitor for Antiaggregant Therapies: From Molecular Pathway to Clinical Application.

Platelets play a significant role in hemostasis, forming plugs at sites of vascular injury to limit blood loss. However, if platelet activation is not controlled, it can lead to thrombotic events, such as myocardial infarction and stroke. To prevent this, antiplatelet agents are used in clinical settings to limit platelet activation in patients at risk of arterial thrombotic events. However, their use can be associated with a significant risk of bleeding. An enhanced comprehension of platelet signaling mechanisms should facilitate the identification of safer targets for antiplatelet therapy. Over the past decade, our comprehension of the breadth and intricacy of signaling pathways that orchestrate platelet activation has expanded exponentially. Several recent studies have provided further insight into the regulation of platelet signaling events and identified novel targets against which to develop novel antiplatelet agents. Antiplatelet drugs are essential in managing atherothrombotic vascular disease. The current antiplatelet therapy in clinical practice is limited in terms of safety and efficacy. Novel compounds have been developed in response to patient variability and resistance to aspirin and/or clopidogrel. Recent studies based on randomized controlled trials and systematic reviews have definitively demonstrated the role of antiplatelet therapy in reducing the risk of cardiovascular events. Antiplatelet therapy is the recommended course of action for patients with established atherosclerosis. These studies compared monotherapy with a P2Y12 inhibitor versus aspirin for secondary prevention. However, in patients undergoing percutaneous coronary intervention, it is still unclear whether the efficacy of P2Y12 inhibitor monotherapy after a short course of dual antiplatelet therapy depends on the type of P2Y12 inhibitor. This paper focuses on the advanced-stage evaluation of several promising antiplatelet drugs.

Somatic Variants Acquired Later in Life Associated with Thoracic Aortic Aneurysms: JAK2 V617F.

The JAK2 V617F somatic variant is a well-known driver of myeloproliferative neoplasms (MPN) associated with an increased risk for athero-thrombotic cardiovascular disease. Recent studies have demonstrated its role in the development of thoracic aortic aneurysm (TAA). However, limited clinical information and level of JAK2 V617F burden have been provided for a comprehensive evaluation of potential confounders. A retrospective genotype-first study was conducted to identify carriers of the JAK2 V617F variant from an internal exome sequencing database in Yale DNA Diagnostics Lab. Additionally, the overall incidence of somatic variants in the JAK2 gene across various tissue types in the healthy population was carried out based on reanalysis of SomaMutDB and data from the UK Biobank (UKBB) cohort to compare our dataset to the population prevalence of the variant. In our database of 12,439 exomes, 594 (4.8%) were found to have a thoracic aortic aneurysm (TAA), and 12 (0.049%) were found to have a JAK2 V617F variant. Among the 12 JAK2 V617F variant carriers, five had a TAA (42%), among whom four had an ascending TAA and one had a descending TAA, with a variant allele fraction ranging from 11.2% to 20%. Among these five patients, 60% were female, and average age at diagnosis was 70 (49-79). The mean ascending aneurysm size was 5.05 cm (range 4.6-5.5 cm), and four patients had undergone surgical aortic replacement or repair. UKBB data revealed a positive correlation between the JAK2 V617F somatic variant and aortic valve disease (effect size 0.0086, p = 0.85) and TAA (effect size = 0.004, p = 0.92), although not statistically significant. An unexpectedly high prevalence of TAA in our dataset (5/594, 0.84%) is greater than the prevalence reported before for the general population, supporting its association with TAA. JAK2 V617F may contribute a meaningful proportion of otherwise unexplained aneurysm patients. Additionally, it may imply a potential JAK2-specific disease mechanism in the developmental of TAA, which suggests a possible target of therapy that warrants further investigation.

STEMI in young patients: what are we dealing with?

Abstract Funding Acknowledgements None. Background/Introduction Acute Myocardial Infarction with ST-segment Elevation (STEMI) in young adults is infrequent, with an incidence ranging from 2-12%. Our objective is to analyse the clinical characteristics, management, and prognosis of patients aged 45 years or younger with STEMI activation. Methods We conducted a retrospective review of the "Code Infarct" registry at our hospital from January 2020 to March 2023. Out of the 867 codes, 51 patients aged 45 or younger were selected. We studied clinical, angiographic, and echocardiographic parameters. Results Table 1 presents the baseline and clinical characteristics of the patients. The median time from symptom onset to the first medical contact was 126 (30-160) minutes, and the median ischemic time was 226 (122-270) minutes. Figure 1 displays the angiographic findings. Atherothrombotic disease was responsible in 78.4% of patients, with 75% of them having single-vessel coronary disease with similar involvement of the right and anterior descending coronary arteries. Five patients (9.8%) experienced spontaneous dissection, with the majority being women (80%). In 5 cases (9.8%), coronary arteries were found to be normal. The second most commonly used antiplatelet agent was prasugrel (64.7%). Fibrinolysis was performed in 5 patients (9.8%). Only 3 patients (5.9%) required inotropic/vasopressor therapy, and 2 (3.9%) received intra-aortic balloon counterpulsation. The most common complication during hospitalization was the occurrence of tachyarrhythmias (27.4%), followed by heart failure (7.8%). At discharge, 52.9% had a left ventricular ejection fraction (LVEF) >55%, 49.3% had LVEF between 40-55%, and only 7.8% had LVEF <40%. The median length of hospital stay was 5.7 (3-6) days, and there were no in-hospital deaths. One-year survival was 98%. Conclusions Atherothrombotic disease is the leading cause of STEMI in individuals aged 45 or younger in our population. Smoking and dyslipidaemia are the most prevalent risk factors. Ischemic time is longer than desired in this group, mainly due to a delay from symptom onset to initial medical contact. Promoting primary prevention and raising awareness about the clinical signs and importance of early diagnosis in STEMI could help reduce ischemic time in this population.Characteristics and Clinical PresentatioCoronary angiography findings.

Abstract 2097: Jak2 V617f Clonal Hematopoiesis Promotes Arterial Thrombosis Via Platelet Activation And Cross-talk

JAK2 V617F ( JAK2 VF ) clonal hematopoiesis (CH) is associated with a marked increase in atherothrombotic cardiovascular disease (CVD). The role of JAK2 VF CH in arterial thrombosis has not been assessed. Using mice simulating JAK2 VF CH, we showed accelerated carotid artery thrombosis, with increased platelet counts and activation and increased leukocytes and red blood cells. There was increased platelet activation in both Jak2 VF and wild type (WT) platelets in Jak2 VF CH suggesting cross-talk between mutant and WT platelets. To assess platelet-specific effects, we used Gp1ba-Cre (VFGp1ba) to selectively express Jak2 VF in platelets. VFGp1ba increased platelet counts to a similar level as in 20% Jak2 VF CH mice but had no effect on leukocyte counts. Like Jak2 VF CH, VFGp1ba increased platelet activation and accelerated arterial thrombosis. Mechanistically, Jak2 VF platelets showed 2.8-fold up-regulation of COX-1, increased activation of cytosolic phospholipase A2, an enzyme important for arachidonic acid generation, and increased thromboxane A2 production. Conditioned media from activated Jak2 VF platelets induced WT platelet activation that was reversed by a thromboxane receptor antagonist. Low dose aspirin ameliorated carotid thrombosis in VFGp1ba and Jak2 VF CH but not in WT control mice. This study shows increased arterial thrombosis in Jak2 VF CH related to Jak2 VF platelet activation and cross-talk with WT platelets via thromboxane, suggesting a potential beneficial role of aspirin treatment in JAK2 VF CH.

Awareness of Atherosclerosis and Cardiovascular Events Among Undergraduate Healthcare Professionals

The word atherosclerosis consists of two parts: atherosis (accumulation of fats accompanied by several macrophages) and sclerosis (fibrosis layer comprising smooth muscle cells. The presence of hyperlipaemia is the major risk issue factor for coronary artery disease. In 2016 advances in atherosclerosis research were focused on the discovery and validation of newly targeted genetics and mechanistic connection to atherothrombotic heart diseases. The Survey on awareness about the risk factors and complications of liver cirrhosis among college students was conducted using a Google form link. We have distributed our survey among 100 college students. Pie charts and Bar diagrams were used to represent output variables. Results showed that the knowledge of cardiovascular 54.00 % said No and 46.00 % said yes. Stroke caused due to lack of blood supply to 44.00 % said heart, 50.00 % said brain, and 6.00 % said I don’t know. These findings conclude that the majority of the population is unaware of the risk factors such as obesity, LDL, and family history, which lead to the development of atherosclerosis, but only a few populations are aware of stress, smoking, coronary heart attack, cholesterol, sleep apnea, HDL, work pressure, physical activity, heart disease, and coronary disease that leads to atherosclerosis.

Abstract P210: Incident Venous Thromboembolism and Subsequent Risk of Cardiovascular Outcomes: The Atherosclerosis Risk in Communities (ARIC) Study

Background: Venous thromboembolism (VTE) and atherothrombosis have different mechanisms of thrombosis formation. A few previous studies reported those having a VTE have greater risk of incident atherothrombotic disease. These studies have several limitations, such as inadequate adjustment for key confounders (e.g., obesity), selected study populations in clinical trials, and small sample size. Moreover, the links of VTE to heart failure (HF) and peripheral artery disease (PAD) are not well understood. Hypothesis: VTE is independently associated with a range of incident cardiovascular outcomes. Methods: In 12,988 ARIC participants without history of VTE or cardiovascular disease at baseline (1987-89), we quantified the association of VTE, as a time-varying exposure, with incident myocardial infarction (MI), stroke, HF, PAD (overall and its severe form, critical limb ischemia [CLI]) using multivariable Cox regression. We also considered unprovoked and provoked VTE separately. Results: Over a median follow-up of 25 years, 901 participants experienced incident VTE. In the same timeframe, there were 1,950 MI events, 1,247 stroke events, 2,981 HF events, and 516 PAD cases (including 207 CLI cases). Participants with VTE, compared to those without, had a higher risk of all cardiovascular outcomes ( Table ). The associations were particularly evident for incident PAD and CLI (adjusted HR 2.32 [95% CI 1.53, 3.52] and 3.44 [2.01, 5.88], respectively). Provoked VTE showed similar associations with all cardiovascular outcomes, whereas unprovoked VTE was significantly associated with MI, HF, and CLI only ( Table ). Conclusions: In this large community-based study, VTE was robustly associated with subsequent risk of different cardiovascular outcomes, independent of potential confounders. Patients with VTE should be considered at high risk of other cardiovascular outcomes and receive optimal preventive therapy for cardiovascular diseases, including atherosclerotic disease and HF.

Primary results of the brazilian registry of atherothrombotic disease (NEAT)

There is limited contemporary prospective real-world evidence of patients with chronic arterial disease in Latin America. The Network to control atherothrombosis (NEAT) registry is a national prospective observational study of patients with known coronary (CAD) and/or peripheral arterial disease (PAD) in Brazil. A total of 2,005 patients were enrolled among 25 sites from September 2020 to March 2022. Patient characteristics, medications and laboratorial data were collected. Primary objective was to assess the proportion of patients who, at the initial visit, were in accordance with good medical practices (domains) for reducing cardiovascular risk in atherothrombotic disease. From the total of patients enrolled, 2 were excluded since they did not meet eligibility criteria. Among the 2,003 subjects included in the analysis, 55.6% had isolated CAD, 28.7% exclusive PAD and 15.7% had both diagnoses. Overall mean age was 66.3 (± 10.5) years and 65.7% were male patients. Regarding evidence-based therapies (EBTs), 4% were not using any antithrombotic drug and only 1.5% were using vascular dose of rivaroxaban (2.5 mg bid). Only 0.3% of the patients satisfied all the domains of secondary prevention, including prescription of EBTs and targets of body-mass index, blood pressure, LDL-cholesterol, and adherence of lifestyle recommendations. The main barrier for prescription of EBTs was medical judgement. Our findings highlight that the contemporary practice does not reflect a comprehensive approach for secondary prevention and had very low incorporation of new therapies in Brazil. Large-scale populational interventions addressing these gaps are warranted to improve the use of evidence-based therapies and reduce the burden of atherothrombotic disease.ClinicalTrials.gov NCT04677725

ATR1 A1166C (rs5186), FII G20210A (rs1799963), FV G1691A (rs6025), FXIII 97G > T (rs11466016) and MTHFR A1298C (rs1801131) polymorphisms and the risk of ST-elevation myocardial infarction in young Mexican individuals.

Previous studies had identified genetic variants associated with Myocardial Infarction, but results are inconclusive. We examined the association between FII G20210A (rs1799963), FV G1691A (rs6025), FXIII 97G > T (rs11466016), ATR1 A1166C (rs5186) and MTHFR A1298C (rs1801131) polymorphisms and ST elevation Myocardial Infarction in young Mexican individuals. We included a total of 350 patients with Myocardial Infarction <45 years old and 350 controls matched by age and gender. The polymorphisms were analyzed by PCR-RFLP using specific restriction enzymes. DNA fragments were separated by electrophoresis in 2% gel of agarose and visualized using SYBR green. The A1166C (p = 0.004) but not FXIII 97G > T (p = 0.19), G20210A (p = 0.32), G1691A (p = No significant) and A1298C (p = 0.21) polymorphisms were associated with increased risk for ST elevation Myocardial Infarction. Moreover, dyslipidemia, hypertension, smoking and family history of atherothrombotic disease were associated. We found that A1166C represented increased risk for ST elevation Myocardial Infarction. However, G20210A, G1691A, 97G > T, and A1298C were not associated. In addition, we had determined that Glu298Asp, PLA1/A2, TAFI Thr325Ile, ACE I/D, AGT M235T and PAI-1 4G/5G polymorphisms represented increased risk in the same group of patients. However, MTHFR C677T, AGT T174M, FV G1691A, TSP-1 N700S, MTHFR C677T and TAFI 174M polymorphisms were no associated. Our results suggest that in young patients with ST Myocardial Infarction, those polymorphisms could contribute to premature endothelial dysfunction, atherothrombosis, vasoconstriction, increased platelet aggregation, muscle cell migration and proliferation. Further studies are required to try to better assess gene-gene and gene-modifiable factors interaction.

Whole Exome Sequencing in Vaccine-Induced Thrombotic Thrombocytopenia (VITT).

Background: In February 2021, a few cases of unusual, severe thrombotic events associated with thrombocytopenia reported after vaccination with ChAdOx1 nCoV-19 (Vaxzevria) or with Johnson & Johnson's Janssen vaccine raise concern about safety. The vaccine-induced thrombotic thrombocytopenia (VITT) has been related to the presence of platelet-activating antibodies directed against platelet Factor 4. Objectives: We investigated VITT subject genetic background by a high-throughput whole exome sequencing (WES) approach in order to investigate VITT genetic predisposition. Methods: Six consecutive patients (females of Caucasian origin with a mean age of 64 years) were referred to the Atherothrombotic Diseases Center (Department of Experimental and Clinical Medicine, Azienda Ospedaliero-Universitaria Careggi, Florence) with a diagnosis of definite VITT underwent WES analysis. WES analysis was performed on the Illumina NextSeq500 platform. Results:WES analysis revealed a total of 140,563 genetic variants. Due to VITT's rare occurrence, we focused attention on rare variants. The global analysis of all high-quality rare variants did not reveal a significant enrichment of mutated genes in biological/functional pathways common to patients analyzed. Afterwards, we focused on rare variants in genes associated with blood coagulation and fibrinolysis, platelet activation and aggregation, integrin-mediated signaling pathway, and inflammation with particular attention to those involved in vascular damage, as well as autoimmune thrombocytopenia. According to ACMG criteria, 47/194 (24.2%) rare variants were classified as uncertain significance variants (VUS), whereas the remaining were likely benign/benign. Conclusion: WES analysis identifies rare variants possibly favoring the prothrombotic state triggered by the exposure to the vaccine. Functional studies and/or extensions to a larger number of patients might allow a more comprehensive definition of these molecular pathways.

Jak2V617F clonal hematopoiesis promotes arterial thrombosis via platelet activation and cross talk

AbstractJAK2V617F (JAK2VF) clonal hematopoiesis (CH) has been associated with atherothrombotic cardiovascular disease (CVD). We assessed the impact of Jak2VF CH on arterial thrombosis and explored the underlying mechanisms. A meta-analysis of 3 large cohort studies confirmed the association of JAK2VF with CVD and with platelet counts and adjusted mean platelet volume (MPV). In mice, 20% or 1.5% Jak2VF CH accelerated arterial thrombosis and increased platelet activation. Megakaryocytes in Jak2VF CH showed elevated proplatelet formation and release, increasing prothrombogenic reticulated platelet counts. Gp1ba-Cre–mediated expression of Jak2VF in platelets (VFGp1ba) increased platelet counts to a similar level as in 20% Jak2VF CH mice while having no effect on leukocyte counts. Like Jak2VF CH mice, VFGp1ba mice showed enhanced platelet activation and accelerated arterial thrombosis. In Jak2VF CH, both Jak2VF and wild-type (WT) platelets showed increased activation, suggesting cross talk between mutant and WT platelets. Jak2VF platelets showed twofold to threefold upregulation of COX-1 and COX-2, particularly in young platelets, with elevated cPLA2 activation and thromboxane A2 production. Compared with controls, conditioned media from activated Jak2VF platelets induced greater activation of WT platelets that was reversed by a thromboxane receptor antagonist. Low-dose aspirin ameliorated carotid artery thrombosis in VFGp1ba and Jak2VF CH mice but not in WT control mice. This study shows accelerated arterial thrombosis and platelet activation in Jak2VF CH with a major role of increased reticulated Jak2VF platelets, which mediate thromboxane cross talk with WT platelets and suggests a potential beneficial effect of aspirin in JAK2VF CH.

Identification of Genetic Loci That Modify the Scarb1 and Apoe Atherothrombotic Phenotype

Introduction: Atherothrombosis, or the formation of a thrombus on a ruptured atherosclerotic plaque, is a major health problem in western societies and can lead to myocardial infarction and ischemic stroke. Atherosclerotic plaques form on the inner walls of blood vessels and consist of macrophages, lipids, and prothrombotic molecules such as tissue factor that initiate the blood clotting process. Despite the complexity of atherothrombotic disease, with major (and evolving) environmental contributors, genetic variants play a role in modifying the disease process. In mice, deficiency of the Scavenger Receptor Class B type 1 (Scarb1) and Apolipoprotein E (ApoE) genes play important roles in the proper maintenance of lipid levels in the body. The Scarb1 protein is an HDL receptor known for its role in the process of transporting cholesterol from peripheral tissues toward the liver for excretion. The ApoE protein combines with lipids to form lipoproteins that package cholesterol and carry it throughout the circulation. In order to study mice deficient in these proteins, our lab produced Scarb1 and ApoE double knockout (dKO) mice on the C57BL/6J (B6) and 129S1/SvImJ (129S1) background and discovered major phenotypic differences in size and survival. Mice with a mixed 129S1/B6 background succumb to lethal atherothrombosis at approximately 8 weeks of age (as seen in Figure 1), whereas dKOs generated on the B6 background die at approximately 5 days old. We hypothesized that specific 129S1 genetic variants modify the severity of atherothrombosis in dKO mice. Methods: We produced F1-F3 generation dKO mice on the mixed 129S1/B6 background for experiments. Weights were taken for the 38 dKO mice and their littermates from 3 weeks old until the death of the knockout mice at around 8 weeks of age. Purified DNA from the dKO mice was subjected to whole genome genotyping for 143,000 markers using the GigaMUGA genotyping platform (Neogen). Weight data were used as a phenotype to perform quantitative trait loci analysis (QTL) to identify potential loci responsible for the phenotypic weight differences. Results: dKO mice from F1-F3 generations were born at the expected Mendelian frequencies but exhibited 3 distinct phenotypes based on their weights relative to their littermates. dKO mouse weights fell into 3 distinct categories: (1) indistinguishable from littermates, (2) 14%-39% less than littermates, (3) greater than 39% less than littermates. QTL analysis identified 6 loci above the significance threshold of 4.04 on Chromosomes (Chr) 1 (LOD 6.82), 2 (LOD 6.44) , 3 (LOD 4.65), 6 (LOD 4.30), 12 (LOD 4.22) and 14 (LOD 5.36; Figure 2). In addition, interaction analyses identified significant interactions of Chr 12 with Chrs 1, 2, 3, and 14. The Chr 12 candidate region is between 83 and 93 Mb consisting of 89 genes. Niemann Pick type C2 ( Npc2), an intracellular cholesterol transporter, is within the candidate region. Thus, 129S1 variants in this region affecting Npc2 transcription are strong candidates for modifying the dKO phenotypes. Discussion: We have analyzed 38 dKO mice for genetic variants affecting their health, as measured by weights relative to their non dKO littermates. We identified 6 significant genetic loci, with Npc2 as a candidate gene for the Chromosome 12 locus. Studies to reinforce these findings include the analysis of an additional cohort of dKO mice to narrow the candidate QTL intervals, analysis of Npc2 expression in the B6 and 129 strain, histology of the liver to visualize lipid accumulation, blood smears to examine the blood cell size difference in dKOs, and sequencing with GigaMUGA. The identification of atherothrombosis modifier genes could result in novel treatment strategies for atherothrombosis.

Analysis of short- and medium-term influence of Polish smog on atherothrombotic cardiovascular diseases in 709 counties in Eastern Europe - preliminary results (EP-Particles study)

Abstract Background Polish smog is a specific type of air pollution characterized by high concentrations of particulate matters (PMs) and benzo(a)pyrene (BaP), which causes exceptionally adverse cardiovascular effects. In Eastern Europe, this is a problem in large cities and also small towns, where residents’ suboptimal heating choices lead to poor air quality. Moreover, myocardial infarction and ischemic stroke (IS) are one of the most common causes of emergency hospitalizations in this area. Purpose We aimed to assess the short- and medium-term impact of multiple air pollutants on the incidence of ST Elevation Myocardial Infarction (STEMI) and IS. Methods We collected data on hospitalizations due to IS and STEMI in the years 2011-2020 from National Health Fund. Effects of PM2.5, PM10, NO2, SO2, O3, CO and BaP were calculated using time-stratified panel data Poisson regression. Results are reported as odds ratio (OR) and 95% Confidence Intervals (95%CI) associated with an increase of the interquartile range (IQR) in a daily concentration of air pollutants on the day of exposure (LAG 0), during the week (LAG 0-6) and month (LAG 0-30) after exposure. The study covered 709 counties located in Eastern Europe with 90 million person-years of follow-up. Results We recorded 159,952 and 68,251 cases of IS and STEMI, respectively. The mean age of patients in IS groups was 73.78 years old and 48.46% of them were men. In the STEMI group mean age was 67.52 years old and males accounted for 64.38%. In the figures, we presented the influence of all analyzed air pollutants on IS (Figure 1) and STEMI (Figure 2) incidence. Exposure to PMs was associated with the highest STEMI (PM2.5: OR=1.086, 95%CI 1.074-1.099, p&amp;lt;0.001; PM10: OR=1.091, 95%CI 1.078-1.104, p&amp;lt;0.001) and IS (PM2.5: OR=1.027, 95%CI 1.019-1.035, p&amp;lt;0.001; PM10: OR=1.028, 95%CI 1.02-1.036, p&amp;lt;0.001) occurrence on LAG 0, and this effect increased during the following month. The IQR increase in BaP concentration was associated with increased IS incidence on LAG 0 (OR=1.009, 95%CI 1.002-1.016, p=0.01), LAG 0-6 (OR=1.012, 95%CI 1.004-1.021, p=0.004) and LAG 0-30 (OR=1.016, 95%CI 1.007-1.026, p=0.001). A similar effect was noted on STEMI occurrence. Exposure to CO was associated with increased IS incidence on all analyzed LAGs, whereas in STEMI it only affected LAG 0-30. The IQR increase in O3 had a protective effect on IS occurrence on LAG 0-6 (OR=0.974, 95%CI 0.962-0.987, p&amp;lt;0.001) and LAG 0-30 (OR=0.967, 95%CI 0.952-0.983, p&amp;lt;0.001), while it had a negative effect on STEMI incidence on LAG 0 (OR=1.023; 95%CI 1.006-1.04, p=0.008). Conclusions Polish smog has a detrimental influence on the incidence of atherothrombotic diseases as a result of the toxic effects of mainly PMs and also other air pollutants. Exposure to air pollution can act as a trigger for STEMI and IS. Furthermore, medium-term exposure also increases the risk of STEMI and IS occurrence, most likely due to cumulative doses of air pollutants.

Abstract 16718: Association of Elevated Lipoprotein A With Adverse Cardiovascular Events Following Percutaneous Coronary Intervention

Background: Patients who undergo percutaneous coronary intervention (PCI) are at increased risk for subsequent cardiovascular (CV) events. Elevated lipoprotein A [Lp(a)] is associated with atherothrombotic disease; however, its role in risk stratification for patients with prior PCI is unknown. Methods: Patients with prior PCI were identified in the Mass General Brigham Lp(a) Registry, a retrospective cohort that included patients who had Lp(a) measured as part of routine care from 2000-2019 and excluded those with severe renal dysfunction (eGFR &lt; 15 mL/min/m 2 , dialysis, or renal transplant) or a malignant neoplasm diagnosis (excepting non-melanoma skin cancers). Lp(a) percentile groups were derived as follows: 1st-50th (ref), 51st-70th, 71st-90th, 91st-100th. The primary outcome was a composite of CV death or myocardial infarction (MI). Results: A total of 2,389 patients with prior PCI were included with a median follow-up period of 12.8 years. Median age was 60 and 583 (24.4%) were women. Higher Lp(a) percentile group was associated with increased incidence of the primary outcome with patients in the 71 st -90 th percentile (112-215 nmol/L) having a HR of 1.39 (95% CI: 1.15-1.69, p = 0.001) and patients in the 91 st -100 th percentile (≥ 216 nmol/L) having a HR: 1.61 (95% CI: 1.26-2.06, p &lt; 0.001). Findings remained significant after adjustment for age, sex, smoking, diabetes, chronic kidney disease, and insulin use with adjusted HR of 1.25 (95% CI: 1.03-1.53, p = 0.024) and adjusted HR of 1.63 (95% CI: 1.27-2.10, p &lt; 0.001) for the 71 st -90 th and 91 st -100 th percentiles, respectively. A similar magnitude of association was observed in evaluating Lp(a) and CV death alone (Figure). Conclusions: Elevated Lp(a) is strongly and independently associated with increased risk of CV death or MI among patients with prior PCI in a stepwise manner that persists over time. Findings support the use of Lp(a) screening in patients with prior PCI to enhance risk stratification.

Evaluation of Cardiovascular Status in Hemophilia Patients in Dezful: Echocardiography, Electrocardiography, and Cardiac Risk Factors

Background: Hemophilia is a congenital bleeding disorder with X-linked inheritance that is associated with a deficiency of coagulation factor 8 (hemophilia A) or 9 (hemophilia B). The protective effect of hemophilia is challenging in the prevention of atherothrombotic heart diseases due to the lack of coagulation factors. Objectives: The present study aims to investigate congenital and acquired heart diseases and atherosclerosis risk factors in hemophilia patients. Methods: In the present cross-sectional descriptive study, electrocardiography (ECG) and echocardiography were performed and evaluated on 50 hemophilia patients in Dezful, southwest Iran. Fasting blood sugar, low-density lipoprotein (LDL), cholesterol, plasma high-density lipoprotein (HDL), systemic blood pressure, and body mass index (BMI) were also calculated. The data were analyzed in SPSS software version 21. The results showed 86% with hemophilia A, 12% with hemophilia B, and one patient (2%) with post-pregnancy hemophilia (mean age = 28.12 ± 14.12 years; age range = 6 - 76 years). Results: The most common congenital heart disease was mitral valve prolapse (MVP) with or without mitral regurgitation, consisting of 5 patients (10%); the most common acquired cardiac disorder was diastolic dysfunction grade I, consisting of 5 patients (10 %), and 2 patients (4%) also had systolic pulmonary artery hypertension (pulmonary artery systolic pressure more than 35 mmHg). Bicuspid aortic valve (BAV), atrial septal defect (ASD), and hypertrophic cardiomyopathy (HCM) were observed in one patient each. Ischemic heart disease was observed only in a 76-year-old patient. Examination of the electrocardiogram had no abnormal findings in the rest, except for two patients with HCM and ASD who had ventricular hypertrophy. The most common risk factor was obesity (16%), followed by hypertension (10%) and dyslipidemia (10%), and only 1 (2%) diabetic patient was identified. Patients with risk factors often had more than one risk factor, were over 30 years old, and had a severe form of hemophilia A. Conclusions: In the examination of echocardiography-ECG and risk factors in hemophilia patients, there was no significant abnormality report, while acquired heart diseases and risk factors proportional to age are evident from 30 years of age onwards.

Incidence of Cardiovascular Disease and Venous Thromboembolism in Patients With Atopic Dermatitis.

Atopic dermatitis (AD) may increase risk for atherothrombotic and cardiovascular (CV) disease. Determine CV disease and venous thromboembolism risk among patients with AD. Cohort study using electronic health data from U.K. general practices in 1994 to 2015. Children (<18 y) and adults (≥18 y) with AD were matched to patients without AD on age, same practice, and encounter date. Treatments and specialist referrals served as proxies of AD severity. Outcomes were incident myocardial infarction, cerebrovascular accident (CVA), diabetes, hypertension, dyslipidemia, deep vein thrombosis (DVT), and pulmonary embolism. Cox regression analysis was used to compare outcomes in AD versus non-AD patients. Comparing 409,341 children with AD (93.2% mild, 5.5% moderate, and 1.3% severe) to 1,809,029 unaffected children, AD was associated with higher risk of DVT (hazard ratio [HR] 1.23; 95% confidence interval [95% CI] 1.02-1.48) and severe AD was associated with higher risk of CVA (HR 2.43; 95% CI 1.13-5.22) and diabetes (HR 1.46; 95% CI 1.06-2.01). Comparing 625,083 adults with AD (65.7% mild, 31.4% moderate, and 2.9% severe) to 2,678,888 unaffected adults, AD, especially when severe, was associated with higher risk of DVT (HR 1.14; 95% CI 1.11-1.18; and HR 1.64; 95% CI 1.49-1.82, respectively) and small but increased risks of CVA, diabetes, and dyslipidemia. Adults with severe AD had higher risk of myocardial infarction (HR 1.27; 95% CI 1.15-1.39), CVA (HR 1.21; 95% CI 1.13-1.30), diabetes (HR 1.15; 95% CI 1.09-1.22), dyslipidemia (HR 1.11; 95% CI 1.06-1.17), and pulmonary embolism (HR 1.39; 95% CI 1.21-1.60) compared with adults without AD. Atopic dermatitis, particularly when severe, is associated with small but increased risks of CV risk factors and events and significantly increased risk of venous thromboembolism.