Clonal Hematopoiesis of Indeterminate Potential Reshapes Age-Related CVD: JACC Review Topic of the Week

Portal vein thrombosis: diagnosis, management, and endpoints for future clinical studies

Portal vein thrombosis (PVT) refers to the development of a non-malignant obstruction of the portal vein, its branches, its radicles, or a combination. This Review first provides a comprehensive overview of all aspects of PVT, namely the specifics of the portal venous system, the risk factors for PVT, the pathophysiology of portal hypertension in PVT, the interest in non-invasive tests, as well as therapeutic approaches including the effect of treating risk factors for PVT or cause of cirrhosis, anticoagulation, portal vein recanalisation by interventional radiology, and prevention and management of variceal bleeding in patients with PVT. Specific issues are also addressed including portal cholangiopathy, mesenteric ischaemia and intestinal necrosis, quality of life, fertility, contraception and pregnancy, and PVT in children. This Review will then present endpoints for future clinical studies in PVT, both in patients with and without cirrhosis, agreed by a large panel of experts through a Delphi consensus process. These endpoints include classification of portal vein thrombus extension, classification of PVT evolution, timing of assessment of PVT, and global endpoints for studies on PVT including clinical outcomes. These endpoints will help homogenise studies on PVT and thus facilitate reporting, comparison between studies, and validation of future studies and trials on PVT.

Chronic TNF in the aging microenvironment exacerbates Tet2 loss-of-function myeloid expansion

ABSTRACT

Somatic mutations in the TET2 gene occur more frequently with age, imparting an intrinsic hematopoietic stem cells (HSCs) advantage and contributing to a phenomenon termed clonal hematopoiesis of indeterminate potential (CHIP). Individuals with TET2-mutant CHIP have a higher risk of developing myeloid neoplasms and other aging-related conditions. Despite its role in unhealthy aging, the extrinsic mechanisms driving TET2-mutant CHIP clonal expansion remain unclear. We previously showed an environment containing tumor necrosis factor (TNF) favors TET2-mutant HSC expansion in vitro. We therefore postulated that age-related increases in TNF also provide an advantage to HSCs with TET2 mutations in vivo. To test this hypothesis, we generated mixed bone marrow chimeric mice of old wild-type (WT) and TNF-/- genotypes reconstituted with WT CD45.1+ and Tet2-/- CD45.2+ HSCs. We show that age-associated increases in TNF dramatically increased the expansion of Tet2-/- cells in old WT recipient mice, with strong skewing toward the myeloid lineage. This aberrant myelomonocytic advantage was mitigated in old TNF-/- recipient mice, suggesting that TNF signaling is essential for the expansion Tet2-mutant myeloid clones. Examination of human patients with rheumatoid arthritis with clonal hematopoiesis revealed that hematopoietic cells carrying certain mutations, including in TET2, may be sensitive to reduced TNF bioactivity following blockade with adalimumab. This suggests that targeting TNF may reduce the burden of some forms of CHIP. To our knowledge, this is the first evidence to demonstrate that TNF has a causal role in driving TET2-mutant CHIP in vivo. These findings highlight TNF as a candidate therapeutic target to control TET2-mutant CHIP.

Clonal hematopoiesis and inflammation in the vasculature: CHIVE, a prospective, longitudinal clonal hematopoiesis cohort and biorepository

ABSTRACT

Clonal hematopoiesis (CH) is an age-associated phenomenon leading to an increased risk of both hematologic malignancy and nonmalignant organ dysfunction. Increasingly available genetic testing has made the incidental discovery of CH clinically common yet evidence-based guidelines and effective management strategies to prevent adverse CH health outcomes are lacking. To address this gap, the prospective CHIVE (clonal hematopoiesis and inflammation in the vasculature) registry and biorepository was created to identify and monitor individuals at risk, support multidisciplinary CH clinics, and refine taxonomy and standards of practice for CH risk mitigation. Data from the first 181 patients enrolled in this prospective registry recapitulate the molecular epidemiology of CH from biobank-scale retrospective studies, with DNMT3A, TET2, ASXL1, and TP53 as the most commonly mutated genes. Blood counts across all hematopoietic lineages trended lower in patients with CH. In addition, patients with CH had higher rates of end organ dysfunction, in particular chronic kidney disease. Among patients with CH, variant allele frequency was independently associated with the presence of cytopenias and progression to hematologic malignancy, whereas other common high-risk CH clone features were not clear. Notably, accumulation of multiple distinct high-risk clone features was also associated with cytopenias and hematologic malignancy progression, supporting a recently published CH risk score. Surprisingly, ∼30% of patients enrolled in CHIVE from CH clinics were adjudicated as not having clonal hematopoiesis of indeterminate potential, highlighting the need for molecular standards and purpose-built assays in this field. Maintenance of this well-annotated cohort and continued expansion of CHIVE to multiple institutions are underway and will be critical to understanding how to thoughtfully care for this patient population.

Clonal Hematopoiesis of Indeterminate Potential and Long-term Outcomes in Heart Transplantation

BACKGROUND

Clonal hematopoiesis of indeterminate potential (CHIP) mutations, a trait of aging, has been associated with the progression of cardiovascular disease and the development of malignancy. Uncertainty prevails regarding a robust association between CHIP and heart-transplantation (HT) outcomes.

OBJECTIVES

To determine the prevalence of CHIP mutations in HT and their association with long-term outcomes, including cardiac allograft vasculopathy (CAV), graft failure, malignancy, and all-cause mortality.

METHODS

We conducted a mixed retrospective-prospective observational study of HT recipients with targeted sequencing for CHIP mutations (variant allele frequency [VAF] of ≥ 2%). The primary composite outcome was the first occurrence of CAV grade ≥ 2, graft failure, malignancy, cardiac retransplantation, or all-cause death. Secondary outcomes were the individual components of the composite primary outcome. Sensitivity analyses with base-case and extreme scenarios were performed.

RESULTS

Among 95 HT recipients, 30 had CHIP mutations (31.6%). DNMT3A mutations were most common (44.7%), followed by PPM1D (13.2%), SF3B1 (10.5%), TET2 (7.9%), and TP53 (7.9%). The only significant independent predictor of CHIP was age at enrollment or age at transplantation. After multivariable adjustment, CHIP mutations were not associated with the primary outcome, which occurred in 44 (46.3%) patients (HR = 0.487; 95% CI:0.197-1.204; P = 0.119), nor were they associated with mlalignancy alone, or death.

CONCLUSION

We demonstrated no association between CHIP mutations and post-transplant outcomes, including CAV, graft failure, malignancy, and all-cause mortality. In line with previously published data, our analysis provides additional evidence about the lack of clinical value of using CHIP mutations as a biomarker for surveillance in outcomes after HT.

Clonal haematopoiesis of indeterminate potential and atrial fibrillation: an east Asian cohort study

BACKGROUND AND AIMS

Both clonal haematopoiesis of indeterminate potential (CHIP) and atrial fibrillation (AF) are age-related conditions. This study investigated the potential role of CHIP in the development and progression of AF.

METHODS

Deep-targeted sequencing of 24 CHIP mutations (a mean depth of coverage = 1000×) was performed in 1004 patients with AF and 3341 non-AF healthy subjects. Variant allele fraction ≥ 2.0% indicated the presence of CHIP mutations. The association between CHIP and AF was evaluated by the comparison of (i) the prevalence of CHIP mutations between AF and non-AF subjects and (ii) clinical characteristics discriminated by CHIP mutations within AF patients. Furthermore, the risk of clinical outcomes-the composite of heart failure, ischaemic stroke, or death-according to the presence of CHIP mutations in AF was investigated from the UK Biobank cohort.

RESULTS

The mean age was 67.6 ± 6.9 vs. 58.5 ± 6.5 years in AF (paroxysmal, 39.0%; persistent, 61.0%) and non-AF cohorts, respectively. CHIP mutations with a variant allele fraction of ≥2.0% were found in 237 (23.6%) AF patients (DNMT3A, 13.5%; TET2, 6.6%; and ASXL1, 1.5%) and were more prevalent than non-AF subjects [356 (10.7%); P < .001] across the age. After multivariable adjustment (age, sex, smoking, body mass index, diabetes, and hypertension), CHIP mutations were 1.4-fold higher in AF [adjusted odds ratio (OR) 1.38; 95% confidence interval 1.10-1.74, P < .01]. The ORs of CHIP mutations were the highest in the long-standing persistent AF (adjusted OR 1.50; 95% confidence interval 1.14-1.99, P = .004) followed by persistent (adjusted OR 1.44) and paroxysmal (adjusted OR 1.33) AF. In gene-specific analyses, TET2 somatic mutation presented the highest association with AF (adjusted OR 1.65; 95% confidence interval 1.05-2.60, P = .030). AF patients with CHIP mutations were older and had a higher prevalence of diabetes, a longer AF duration, a higher E/E', and a more severely enlarged left atrium than those without CHIP mutations (all P < .05). In UK Biobank analysis of 21 286 AF subjects (1297 with CHIP and 19 989 without CHIP), the CHIP mutation in AF is associated with a 1.32-fold higher risk of a composite clinical event (heart failure, ischaemic stroke, or death).

CONCLUSIONS

CHIP mutations, primarily DNMT3A or TET2, are more prevalent in patients with AF than non-AF subjects whilst their presence is associated with a more progressive nature of AF and unfavourable clinical outcomes.

Individual and Neighborhood-level Socioeconomic Status and Somatic Mutations Associated With Increased Risk of Cardiovascular Disease and Mortality: A Cross-Sectional Analysis in the Women's Health Initiative

BACKGROUND

Clonal hematopoiesis of indeterminate potential (CHIP), the expansion of leukemogenic mutations in white blood cells, has been associated with increased risk of atherosclerotic cardiovascular diseases, cancer, and mortality.

OBJECTIVE

We examined the relationship between individual- and neighborhood-level socioeconomic status (SES) and CHIP and evaluated effect modification by interpersonal and intrapersonal resources.

METHODS

The study population included 10,799 postmenopausal women from the Women's Health Initiative without hematologic malignancy or antineoplastic medication use. Individual- and neighborhood (Census tract)-level SES were assessed across several domains including education, income, and occupation, and a neighborhood-level SES summary z-score, which captures multiple dimensions of SES, was generated. Interpersonal and intrapersonal resources were self-reports. CHIP was ascertained based on a prespecified list of leukemogenic driver mutations. Weighted logistic regression models adjusted for covariates were used to estimate risk of CHIP as an odds ratio (OR) and 95% confidence interval (95% CI).

RESULTS

The interval-scale neighborhood-level SES summary z-score was associated with a 3% increased risk of CHIP: OR (95% CI) = 1.03 (1.00-1.05), p = .038. Optimism significantly modified that estimate, such that among women with low/medium and high levels of optimism, the corresponding ORs (95% CIs) were 1.03 (1.02-1.04) and 0.95 (0.94-0.96), pInteraction < .001.

CONCLUSIONS

Our findings suggest that reduced risk of somatic mutation may represent a biological pathway by which optimism protects contextually advantaged but at-risk women against age-related chronic disease and highlight potential benefits of long-term, positive psychological interventions.

Geroscience and pathology: a new frontier in understanding age-related diseases

Geroscience, a burgeoning discipline at the intersection of aging and disease, aims to unravel the intricate relationship between the aging process and pathogenesis of age-related diseases. This paper explores the pivotal role played by geroscience in reshaping our understanding of pathology, with a particular focus on age-related diseases. These diseases, spanning cardiovascular and cerebrovascular disorders, malignancies, and neurodegenerative conditions, significantly contribute to the morbidity and mortality of older individuals. We delve into the fundamental cellular and molecular mechanisms underpinning aging, including mitochondrial dysfunction and cellular senescence, and elucidate their profound implications for the pathogenesis of various age-related diseases. Emphasis is placed on the importance of assessing key biomarkers of aging and biological age within the realm of pathology. We also scrutinize the interplay between cellular senescence and cancer biology as a central area of focus, underscoring its paramount significance in contemporary pathological research. Moreover, we shed light on the integration of anti-aging interventions that target fundamental aging processes, such as senolytics, mitochondria-targeted treatments, and interventions that influence epigenetic regulation within the domain of pathology research. In conclusion, the integration of geroscience concepts into pathological research heralds a transformative paradigm shift in our understanding of disease pathogenesis and promises breakthroughs in disease prevention and treatment.

Lipid droplets, autophagy, and ageing: A cell-specific tale

Lipid droplets are the essential organelle for storing lipids in a cell. Within the variety of the human body, different cells store, utilize and release lipids in different ways, depending on their intrinsic function. However, these differences are not well characterized and, especially in the context of ageing, represent a key factor for cardiometabolic diseases. Whole body lipid homeostasis is a central interest in the field of cardiometabolic diseases. In this review we characterize lipid droplets and their utilization via autophagy and describe their diverse fate in three cells types central in cardiometabolic dysfunctions: adipocytes, hepatocytes, and macrophages.

Shared and Reciprocal Mechanisms Between Heart Failure and Cancer - An Emerging Concept of Heart-Cancer Axis

Epidemiological evidence of increased risks of cancer in heart failure (HF) patients and HF in cancer patients has suggested close relationships between the pathogenesis of both diseases. Indeed, HF and cancer share common risk factors, including aging and unhealthy lifestyles, and underlying mechanisms, including activation of the sympathetic nervous system and renin-angiotensin-aldosterone system, chronic inflammation, and clonal hematopoiesis of indeterminate potential. Mechanistically, HF accelerates cancer development and progression via secreted factors, so-called cardiokines, and epigenetic remodeling of bone marrow cells into an immunosuppressive phenotype. Reciprocally, cancer promotes HF via cachexia-related wasting and metabolic remodeling in the heart, and possibly via cancer-derived extracellular vesicles influencing myocardial structure and function. The novel concept of the "heart-cancer axis" will help in our understanding of the shared and reciprocal relationships between HF and cancer, and provide innovative diagnostic and therapeutic approaches for both diseases.

Defining the clinical validity of genes reported to cause pulmonary arterial hypertension

PURPOSE

Pulmonary arterial hypertension (PAH) is a rare, progressive vasculopathy with significant cardiopulmonary morbidity and mortality. Genetic testing is currently recommended for adults diagnosed with heritable, idiopathic, anorexigen-, hereditary hemorrhagic telangiectasia-, and congenital heart disease-associated PAH, PAH with overt features of venous/capillary involvement, and all children diagnosed with PAH. Variants in at least 27 genes have putative evidence for PAH causality. Rigorous assessment of the evidence is needed to inform genetic testing.

METHODS

An international panel of experts in PAH applied a semi-quantitative scoring system developed by the NIH Clinical Genome Resource to classify the relative strength of evidence supporting PAH gene-disease relationships based on genetic and experimental evidence.

RESULTS

Twelve genes (BMPR2, ACVRL1, ATP13A3, CAV1, EIF2AK4, ENG, GDF2, KCNK3, KDR, SMAD9, SOX17, and TBX4) were classified as having definitive evidence and 3 genes (ABCC8, GGCX, and TET2) with moderate evidence. Six genes (AQP1, BMP10, FBLN2, KLF2, KLK1, and PDGFD) were classified as having limited evidence for causal effects of variants. TOPBP1 was classified as having no known PAH relationship. Five genes (BMPR1A, BMPR1B, NOTCH3, SMAD1, and SMAD4) were disputed because of a paucity of genetic evidence over time.

CONCLUSION

We recommend that genetic testing includes all genes with definitive evidence and that caution be taken in the interpretation of variants identified in genes with moderate or limited evidence. Genes with no known evidence for PAH or disputed genes should not be included in genetic testing.

Clonal Hematopoiesis of Indeterminate Potential and Cardiovascular Risk in Patients with Chronic Kidney Disease without Previous Cardiac Pathology

Clonal hematopoiesis of indeterminate potential (CHIP) is defined by the clonal expansion of hematopoietic stem cells carrying certain genes associated with an increased risk of hematological malignancies. Our study analyzes the influence of CHIP on the risk of heart disease and cardiovascular events in a population with chronic kidney disease (CKD). A total of 128 patients were prospectively followed up for 18 months to detect major cardiovascular events (MACE). To detect the presence of silent heart disease, troponin I, NT-Pro-BNP, and coronary calcification were measured. A massive sequencing was performed to detect CHIP. A total of 24.2% of the patients presented CHIP, including that which was only pathogenic. The most frequently affected gene was TET2 (21.1%). Using multivariate logistic regression analysis, the presence of CHIP was not related to coronary calcification (OR 0.387, 95% CI 0.142-1.058, p = 0.387), nor was it related to troponin I or NT-Pro-BNP. A total of nine patients developed major cardiovascular events. Patients with CHIP did not have a higher risk of major cardiovascular events, although patients with DNMT3A did have a higher risk (HR 6.637, 95% CI 1.443-30.533, p = 0.015), independent of other variables. We did not find that CHIP was associated with a greater risk of silent heart disease or cardiovascular events, although those affected by DNMT3a, analyzed independently, were associated with a greater number of cardiovascular events.

Risk of Cancer After Diagnosis of Cardiovascular Disease

Background

Cardiovascular disease (CVD) and cancer share several risk factors. Although preclinical models show that various types of CVD can accelerate cancer progression, clinical studies have not determined the impact of atherosclerosis on cancer risk.

Objectives

The objective of this study was to determine whether CVD, especially atherosclerotic CVD, is independently associated with incident cancer.

Methods

Using IBM MarketScan claims data from over 130 million individuals, 27 million cancer-free subjects with a minimum of 36 months of follow-up data were identified. Individuals were stratified by presence or absence of CVD, time-varying analysis with multivariable adjustment for cardiovascular risk factors was performed, and cumulative risk of cancer was calculated. Additional analyses were performed according to CVD type (atherosclerotic vs nonatherosclerotic) and cancer subtype.

Results

Among 27,195,088 individuals, those with CVD were 13% more likely to develop cancer than those without CVD (HR: 1.13; 95% CI: 1.12-1.13). Results were more pronounced for individuals with atherosclerotic CVD (aCVD), who had a higher risk of cancer than those without CVD (HR: 1.20; 95% CI: 1.19-1.21). aCVD also conferred a higher risk of cancer compared with those with nonatherosclerotic CVD (HR: 1.11; 95% CI: 1.11-1.12). Cancer subtype analyses showed specific associations of aCVD with several malignancies, including lung, bladder, liver, colon, and other hematologic cancers.

Conclusions

Individuals with CVD have an increased risk of developing cancer compared with those without CVD. This association may be driven in part by the relationship of atherosclerosis with specific cancer subtypes, which persists after controlling for conventional risk factors.

Clonal Hematopoiesis of Indeterminate Potential From a Heart Failure Specialist's Point of View

Clonal hematopoiesis of indeterminate potential (CHIP) is a common bone marrow abnormality induced by age-related DNA mutations, which give rise to proinflammatory immune cells. These immune cells exacerbate atherosclerotic cardiovascular disease and may induce or accelerate heart failure. The mechanisms involved are complex but point toward a central role for proinflammatory macrophages and an inflammasome-dependent immune response (IL-1 [interleukin-1] and IL-6 [interleukin-6]) in the atherosclerotic plaque or directly in the myocardium. Intracardiac inflammation may decrease cardiac function and induce cardiac fibrosis, even in the absence of atherosclerotic cardiovascular disease. The pathophysiology and consequences of CHIP may differ among implicated genes as well as subgroups of patients with heart failure, based on cause (ischemic versus nonischemic) and ejection fraction (reduced ejection fraction versus preserved ejection fraction). Evidence is accumulating that CHIP is associated with cardiovascular mortality in ischemic and nonischemic heart failure with reduced ejection fraction and involved in the development of heart failure with preserved ejection fraction. CHIP and corresponding inflammatory pathways provide a highly potent therapeutic target. Randomized controlled trials in patients with well-phenotyped heart failure, where readily available anti-inflammatory therapies are used to intervene with clonal hematopoiesis, may pave the way for a new area of heart failure treatment. The first clinical trials that target CHIP are already registered.

Emerging evidence on the role of clonal hematopoiesis of indeterminate potential in chronic kidney disease

Chronic kidney disease (CKD) was responsible for 1.2 million deaths globally in 2016. Despite the large and growing burden of CKD, treatment options are limited and generally only preserve kidney function. Characterizing molecular precursors to incident and progressive CKD could point to critically needed prevention and treatment strategies. Clonal hematopoiesis of indeterminate potential (CHIP) is typically characterized by the clonal expansion of blood cells carrying somatic mutations in specific driver genes. An age-related disorder, CHIP is rare in the young but common in older adults. Recent studies have identified causal associations between CHIP and atherosclerotic cardiovascular disease which are most likely mediated by inflammation, a hallmark of CKD. Animal evidence has supported causal effects of CHIP on kidney injury, inflammation, and fibrosis, providing impetus for human research. Although prospective epidemiologic studies investigating associations of CHIP with development and progression of CKD are few, intriguing findings have been reported. CHIP was significantly associated with kidney function decline and end stage kidney disease in the general population, although effect sizes were modest. Recent work suggests larger associations of CHIP with kidney disease progression in CKD patients, but further investigations in this area are needed. In addition, the accumulating literature has identified some heterogeneity in associations between CHIP and kidney endpoints across study populations, but reasons for these differences remain unclear. The current review provides an in-depth exploration into this nascent area of research, develops a conceptual framework linking CHIP to CKD, and discusses the clinical and public health implications of this work.

CHIPing away the progression potential of CHIP: A new reality in the making

Over the past few years, we have gained a deeper understanding of clonal hematopoiesis of indeterminate potential (CHIP), especially with regard to the epidemiology, clinical sequelae, and mechanical aspects. However, interventional strategies to prevent or delay the potential negative consequences of CHIP remain underdeveloped. In this review, we highlight the latest updates on clonal hematopoiesis research, including molecular mechanisms and clinical implications, with a particular focus on the evolving strategies for the interventions that are being evaluated in ongoing observational and interventional trials. There remains an urgent need to formulate standardized and evidence-based recommendations and guidelines for evaluating and managing individuals with clonal hematopoiesis. In addition, patient-centric endpoints must be defined for clinical trials, which will enable us to continue the robust development of effective preventive strategies and improve clinical outcomes.

Multiple myeloma, a quintessential malignant disease of aging: a geroscience perspective on pathogenesis and treatment

Multiple myeloma (MM) is an incurable plasma cell malignancy, which is predominantly a disease of older adults (the median age at diagnosis is 70 years). The slow progression from asymptomatic stages and the late-onset of MM suggest fundamental differences compared to many other hematopoietic system-related malignancies. The concept discussed in this review is that age-related changes at the level of terminally differentiated plasma cells act as the main risk factors for the development of MM. Epigenetic and genetic changes that characterize both MM development and normal aging are highlighted. The relationships between cellular aging processes, genetic mosaicism in plasma cells, and risk for MM and the stochastic processes contributing to clonal selection and expansion of mutated plasma cells are investigated. In line with the DNA damage accumulation theory of aging, in this review, the evolution of monoclonal gammopathy to symptomatic MM is considered. Therapeutic consequences of age-dependent comorbidities that lead to frailty and have fundamental influence on treatment outcome are described. The importance of considering geriatric states when planning the life-long treatment course of an elderly MM patient in order to achieve maximal therapeutic benefit is emphasized.

The Role of Inflammation in Cardiovascular Disease

Atherosclerosis is a chronic inflammatory disease, in which the immune system has a prominent role in its development and progression. Inflammation-induced endothelial dysfunction results in an increased permeability to lipoproteins and their subendothelial accumulation, leukocyte recruitment, and platelets activation. Recruited monocytes differentiate into macrophages which develop pro- or anti-inflammatory properties according to their microenvironment. Atheroma progression or healing is determined by the balance between these functional phenotypes. Macrophages and smooth muscle cells secrete inflammatory cytokines including interleukins IL-1β, IL-12, and IL-6. Within the arterial wall, low-density lipoprotein cholesterol undergoes an oxidation. Additionally, triglyceride-rich lipoproteins and remnant lipoproteins exert pro-inflammatory effects. Macrophages catabolize the oxidized lipoproteins and coalesce into a lipid-rich necrotic core, encapsulated by a collagen fibrous cap, leading to the formation of fibro-atheroma. In the conditions of chronic inflammation, macrophages exert a catabolic effect on the fibrous cap, resulting in a thin-cap fibro-atheroma which makes the plaque vulnerable. However, their morphology may change over time, shifting from high-risk lesions to more stable calcified plaques. In addition to conventional cardiovascular risk factors, an exposure to acute and chronic psychological stress may increase the risk of cardiovascular disease through inflammation mediated by an increased sympathetic output which results in the release of inflammatory cytokines. Inflammation is also the link between ageing and cardiovascular disease through increased clones of leukocytes in peripheral blood. Anti-inflammatory interventions specifically blocking the cytokine pathways reduce the risk of myocardial infarction and stroke, although they increase the risk of infections.

Hematopoiesis of Indeterminate Potential and Atherothrombotic Risk

Hematopoiesis is the process of blood production, essential for the continued supply of immune cells and red blood cells. However, the proliferative nature of hematopoietic stem cells (HSCs) renders them susceptible to developing somatic mutations. HSCs carrying a mutation can gain a selective advantage over normal HSCs and result in hematological disorders. One such disorder is termed clonal hematopoiesis of indeterminate potential (CHIP), a premalignant state associated with aging, where the mutant HSCs are responsible for producing a small portion of mature immune cells in the circulation and subsequently in tissues. People with CHIP have been shown to have an increased risk of mortality due to cardiovascular disease (CVD). Why this occurs is under rigorous investigation, but the majority of the studies to date have suggested that increased atherosclerosis is due to heightened inflammatory cytokine release from mutant lesional macrophages. However, given CHIP is driven by several mutations, other hematopoietic lineages can be altered to promote CVD. In this review we explore the relationship between mutations in genes causing CHIP and atherothrombotic disorders, along with potential mechanisms of enhanced clonal outgrowth and potential therapies and strategies to slow CHIP progression.

Somatic Mutations and Clonal Hematopoiesis as Drivers of Age-Related Cardiovascular Risk

Purpose of Review

Clonal hematopoiesis of indeterminate potential (CHIP) has been identified as a novel cardiovascular risk factor. Here we review the relationship of lifestyle and environmental risk factors predisposing to somatic mutations and CHIP and provide an overview on age-related cardiovascular outcomes.

Recent Findings

CHIP has been associated with accelerated atherosclerosis and cardiovascular disease in both epidemiological and experimental studies. The most commonly mutated candidate driver genes are DNMT3A, TET2, JAK2, and ASXL1. The underlying mechanisms appear predominantly related to inflammatory pathways. Although age is the dominant risk factor for developing CHIP, emerging evidence suggests that other factors such as smoking, obesity/type 2 diabetes, or an unhealthy diet play a role in the occurrence of somatic mutations.

Summary

Evidence suggests a strong link between vascular risk factors, somatic hematopoietic mutations, and age-related cardiovascular disease. Further studies on CHIP biology are required to identify targeted interventions for risk reduction in patients with CHIP and inform the utility of screening strategies.

Understanding the biological mechanisms of cancer treatment-induced cardiac toxicity

While many strides have been made in the multidisciplinary science of Cardio-Oncology, gaps in knowledge remain despite these advances to identify optimal strategies of detection and treatment of cancer treatment-associated cardiotoxicity. Many opportunities are available for advocates from all avenues of the field to transform cardio-oncology from a reactionary to a preventative science.

Cardiovascular Disease Risk Modeling for Astronauts: Making the Leap From Earth to Space

NASA has recently completed several long-duration missions to the International Space Station and is solidifying plans to return to the Moon, with an eye toward Mars and beyond. As NASA pushes the boundaries of human space exploration, the hazards of spaceflight, including space radiation, levy an increasing burden on astronaut health and performance. The cardiovascular system may be especially vulnerable due to the combined impacts of space radiation exposure, lack of gravity, and other spaceflight hazards. On Earth, the risk for cardiovascular disease (CVD) following moderate to high radiation doses is well-established from clinical, environmental, and occupational exposures (largely from gamma- and x-rays). Less is known about CVD risks associated with high-energy charged ions found in space and increasingly used in radiotherapy applications on Earth, making this a critical area of investigation for occupational radiation protection. Assessing CVD risk is complicated by its multifactorial nature, where an individual's risk is strongly influenced by factors such as family history, blood pressure, and lipid profiles. These known risk factors provide the basis for development of a variety of clinical risk prediction models (CPMs) that inform the likelihood of medical outcomes over a defined period. These tools improve clinical decision-making, personalize care, and support primary prevention of CVD. They may also be useful for individualizing risk estimates for CVD following radiation exposure both in the clinic and in space. In this review, we summarize unique aspects of radiation risk assessment for astronauts, and we evaluate the most widely used CVD CPMs for their use in NASA radiation risk assessment applications. We describe a comprehensive dual-use risk assessment framework that supports both clinical care and operational management of space radiation health risks using quantitative metrics. This approach is a first step in using personalized medicine for radiation risk assessment to support safe and productive spaceflight and long-term quality of life for NASA astronauts.

Modern Concepts in Cardiovascular Disease: Inflamm-Aging

The improvements in healthcare services and quality of life result in a longer life expectancy and a higher number of aged individuals, who are inevitably affected by age-associated cardiovascular (CV) diseases. This challenging demographic shift calls for a greater effort to unravel the molecular mechanisms underlying age-related CV diseases to identify new therapeutic targets to cope with the ongoing aging "pandemic". Essential for protection against external pathogens and intrinsic degenerative processes, the inflammatory response becomes dysregulated with aging, leading to a persistent state of low-grade inflammation known as inflamm-aging. Of interest, inflammation has been recently recognized as a key factor in the pathogenesis of CV diseases, suggesting inflamm-aging as a possible driver of age-related CV afflictions and a plausible therapeutic target in this context. This review discusses the molecular pathways underlying inflamm-aging and their involvement in CV disease. Moreover, the potential of several anti-inflammatory approaches in this context is also reviewed.

Foam Cells in Atherosclerosis: Novel Insights Into Its Origins, Consequences, and Molecular Mechanisms

Foam cells play a vital role in the initiation and development of atherosclerosis. This review aims to summarize the novel insights into the origins, consequences, and molecular mechanisms of foam cells in atherosclerotic plaques. Foam cells are originated from monocytes as well as from vascular smooth muscle cells (VSMC), stem/progenitor cells, and endothelium cells. Novel technologies including lineage tracing and single-cell RNA sequencing (scRNA-seq) have revolutionized our understanding of subtypes of monocyte- and VSMC-derived foam cells. By using scRNA-seq, three main clusters including resident-like, inflammatory, and triggering receptor expressed on myeloid cells-2 (Trem2 hi ) are identified as the major subtypes of monocyte-derived foam cells in atherosclerotic plaques. Foam cells undergo diverse pathways of programmed cell death including apoptosis, autophagy, necroptosis, and pyroptosis, contributing to the necrotic cores of atherosclerotic plaques. The formation of foam cells is affected by cholesterol uptake, efflux, and esterification. Novel mechanisms including nuclear receptors, non-coding RNAs, and gut microbiota have been discovered and investigated. Although the heterogeneity of monocytes and the complexity of non-coding RNAs make obstacles for targeting foam cells, further in-depth research and therapeutic exploration are needed for the better management of atherosclerosis.

Old blood from heterochronic parabionts accelerates vascular aging in young mice: transcriptomic signature of pathologic smooth muscle remodeling

Vascular aging has a central role in the pathogenesis of cardiovascular diseases contributing to increased mortality of older adults. There is increasing evidence that, in addition to the documented role of cell-autonomous mechanisms of aging, cell-nonautonomous mechanisms also play a critical role in the regulation of vascular aging processes. Our recent transcriptomic studies (Kiss T. et al. Geroscience. 2020;42(2):727-748) demonstrated that circulating anti-geronic factors from young blood promote vascular rejuvenation in aged mice. The present study was designed to expand upon the results of this study by testing the hypothesis that circulating pro-geronic factors also contribute to the genesis of vascular aging phenotypes. To test this hypothesis, through heterochronic parabiosis, we determined the extent to which shifts in the vascular transcriptome (RNA-seq) are modulated by the old systemic environment. We reanalyzed existing RNA-seq data, comparing the transcriptome in the aorta arch samples isolated from isochronic parabiont aged (20-month-old) C57BL/6 mice [A-(A); parabiosis for 8 weeks] and young isochronic parabiont (6-month-old) mice [Y-(Y)] and also assessing transcriptomic changes in the aortic arch in young (6-month-old) parabiont mice [Y-(A); heterochronic parabiosis for 8 weeks] induced by the presence of old blood derived from aged (20-month-old) parabionts. We identified 528 concordant genes whose expression levels differed in the aged phenotype and were shifted towards the aged phenotype by the presence of old blood in young Y-(A) animals. Among them, the expression of 221 concordant genes was unaffected by the presence of young blood in A-(Y) mice. GO enrichment analysis suggests that old blood-regulated genes may contribute to pathologic vascular remodeling. IPA Upstream Regulator analysis (performed to identify upstream transcriptional regulators that may contribute to the observed transcriptomic changes) suggests that the mechanism of action of pro-geronic factors present in old blood may include inhibition of pathways mediated by SRF (serum response factor), insulin-like growth factor-1 (IGF-1) and VEGF-A. In conclusion, relatively short-term exposure to old blood can accelerate vascular aging processes. Our findings provide additional evidence supporting the significant plasticity of vascular aging and the existence of circulating pro-geronic factors mediating pathological remodeling of the vascular smooth muscle cells and the extracellular matrix.

Clonal Hematopoiesis Is Associated With Higher Risk of Stroke

BACKGROUND AND PURPOSE

Clonal hematopoiesis of indeterminate potential (CHIP) is a novel age-related risk factor for cardiovascular disease-related morbidity and mortality. The association of CHIP with risk of incident ischemic stroke was reported previously in an exploratory analysis including a small number of incident stroke cases without replication and lack of stroke subphenotyping. The purpose of this study was to discover whether CHIP is a risk factor for ischemic or hemorrhagic stroke.

METHODS

We utilized plasma genome sequence data of blood DNA to identify CHIP in 78 752 individuals from 8 prospective cohorts and biobanks. We then assessed the association of CHIP and commonly mutated individual CHIP driver genes (DNMT3A, TET2, and ASXL1) with any stroke, ischemic stroke, and hemorrhagic stroke.

RESULTS

CHIP was associated with an increased risk of total stroke (hazard ratio, 1.14 [95% CI, 1.03-1.27]; P=0.01) after adjustment for age, sex, and race. We observed associations with CHIP with risk of hemorrhagic stroke (hazard ratio, 1.24 [95% CI, 1.01-1.51]; P=0.04) and with small vessel ischemic stroke subtypes. In gene-specific association results, TET2 showed the strongest association with total stroke and ischemic stroke, whereas DMNT3A and TET2 were each associated with increased risk of hemorrhagic stroke.

CONCLUSIONS

CHIP is associated with an increased risk of stroke, particularly with hemorrhagic and small vessel ischemic stroke. Future studies clarifying the relationship between CHIP and subtypes of stroke are needed.

Clinical determinants of coronary artery disease burden and vulnerability using optical coherence tomography co-registered with intravascular ultrasound

OBJECTIVES

We investigated clinical determinants of disease burden and vulnerability using optical coherence tomography (OCT) co-registered with intravascular ultrasound (IVUS) in a large cohort of patients.

METHODS

A total of 704 patients [44.5% with acute coronary syndromes (ACS)] underwent coronary intervention. IVUS plaque burden and OCT lipid, macrophage and calcium indices and the presence of thrombus, plaque rupture and thin-cap fibroatheroma (TCFA) were analyzed.

RESULTS

Median patient age was 66 years with 81.8% men, 34.4% with diabetes mellitus and 15.5% with preadmission statins. Median lesion length was 25.7 mm, and 33.0% had a TCFA. Adjusted models indicated (1) older patient age was related to more calcium, but fewer macrophages; (2) men were related to more thrombus with plaque rupture while women had more thrombus without plaque rupture; (3) ACS presentation was related to morphological acute thrombotic events (more thrombus with/without rupture) and plaque vulnerability (more TCFA, more lipid and macrophages and larger plaque burden); (4) diabetes mellitus was related to a greater atherosclerotic disease burden (more lipid and calcium and larger plaque burden) and more thrombus without rupture; (5) hypertension was related to more macrophages; (6) current smoking was related to less calcium; and (7) renal insufficiency and preadmission statin therapy were not independently associated with IVUS or OCT plaque morphology.

CONCLUSION

Patient characteristics, especially diabetes mellitus and aging, affect underlying atherosclerotic burden, among which a greater lipidic burden along with sex differences influence local thrombotic morphology that affects clinical presentation.

Inflammation as a mechanism and therapeutic target in peripheral artery disease

Peripheral artery disease is one of three major clinical manifestations of atherosclerosis, the other two being coronary artery and cerebrovascular disease. Despite progress in surgery, antithrombotic therapy and therapies that modify conventional risk factors (lipid-, blood pressure-, and glucose-lowering interventions), patients with peripheral artery disease have unacceptably high risk of vascular complications. Additional strategies to reduce this residual risk are needed. The accumulated evidence that inflammation plays an important role in the pathogenesis of atherosclerosis has spurred recent efforts to evaluate anti-inflammatory agents as an additional therapeutic approach for atherothrombosis prevention and treatment. In this review, we examine the evidence supporting the role of inflammation in atherosclerosis, review recent trials evaluating anti-inflammatory approaches to reduce cardiovascular complications, and offer insights into the opportunities for novel anti-inflammatory strategies to reduce the burden of cardiovascular and limb complications in patients with peripheral artery disease.

Inflammation as A Precursor of Atherothrombosis, Diabetes and Early Vascular Aging

Vascular disease was for a long time considered a disease of the old age, but it is becoming increasingly clear that a cumulus of factors can cause early vascular aging (EVA). Inflammation plays a key role in vascular stiffening and also in other pathologies that induce vascular damage. There is a known and confirmed connection between inflammation and atherosclerosis. However, it has taken a long time to prove the beneficial effects of anti-inflammatory drugs on cardiovascular events. Diabetes can be both a product of inflammation and a cofactor implicated in the progression of vascular disease. When diabetes and inflammation are accompanied by obesity, this ominous trifecta leads to an increased incidence of atherothrombotic events. Research into earlier stages of vascular disease, and documentation of vulnerability to premature vascular disease, might be the key to success in preventing clinical events. Modulation of inflammation, combined with strict control of classical cardiovascular risk factors, seems to be the winning recipe. Identification of population subsets with a successful vascular aging (supernormal vascular aging-SUPERNOVA) pattern could also bring forth novel therapeutic interventions.

A Vicious Circle of Clonal Haematopoiesis of Indeterminate Potential and Cardiovascular Disease

Clonal haematopoiesis of indeterminate potential (CHIP) represents a recently identified overlap between cancer and cardiovascular disease (CVD). CHIP develops as a result of certain acquired somatic mutations that predispose to leukaemia, but clinically even more prevalent, associate with increased risk for CVD and CVD-related death. Experimental studies suggest a causal role for CHIP aggravating inflammatory processes in CVD, and recent epidemiologic and genetic studies indicate that classical CVD risk factors may increase the risk of acquiring CHIP driver mutations, thus fuelling a vicious circle. The potential mechanism underlying the associative link between CHIP and CVD and mortality has been the focus of a few recent excellent experimental and observational studies which are summarized and discussed in this concise non-systematic review article. These data support a pathomechanistic view of a spiralling vicious circle in which CHIP aggravates the inflammatory immune response in CVD, and CVD-driven elevated haematopoietic activity promotes CHIP development.

Common Pathophysiology in Cancer, Atrial Fibrillation, Atherosclerosis, and Thrombosis: JACC: CardioOncology State-of-the-Art Review

Cardiovascular disease and cancer are the 2 leading causes of death worldwide. Emerging evidence suggests common mechanisms between cancer and cardiovascular disease, including atrial fibrillation and atherosclerosis. With advances in cancer therapies, screening, and diagnostics, cancer-specific survival and outcomes have improved. This increase in survival has led to the coincidence of cardiovascular disease, including atrial fibrillation and atherosclerosis, as patients with cancer live longer. Additionally, cancer and cardiovascular disease share several risk factors and underlying pathophysiologic mechanisms, including inflammation, cancer-related factors including treatment effects, and alterations in platelet function. Patients with cancer are at increased risk for bleeding and thrombosis compared with the general population. Although optimal antithrombotic therapy, including agent choice and duration, has been extensively studied in the general population, this area remains understudied in patients with cancer despite their altered thrombotic and bleeding risk. Future investigation, including incorporation of cancer-specific characteristics to traditional thrombotic and bleeding risk scores, clinical trials in the cancer population, and the development of novel antithrombotic and anti-inflammatory strategies on the basis of shared pathophysiologic mechanisms, is warranted to improve outcomes in this patient population.

Persistent inflammatory residual risk despite aggressive cholesterol-lowering therapy: what is next?

PURPOSE OF REVIEW

To briefly summarize recently published evidence on the possible therapeutic modulation of inflammatory processes in atherosclerotic cardiovascular disease (ASCVD), focusing on the rationale for an additional randomized clinical trial, targeting both persistently elevated cholesterol and inflammatory residual risk and critically discuss still open issues and future perspectives with regard to treatment allocation.

RECENT FINDINGS

Several large-scale clinical trials over the past few years have advanced our understanding of the role of inflammation in atherosclerosis, demonstrating that targeting the NLRP3 inflammasome and the IL-1β pathway indeed represent a new avenue to reduce residual risk in patients with ASCVD. However, despite optimal lipid-lowering therapy and novel options to modulate residual inflammatory risk, there are still a large number of individuals, being at high risk for recurrent ASCVD events.

SUMMARY

The integration of a dual target strategy aimed at lowering the inflammatory burden in combination with aggressive lipid-modifying for those at high/very high ASCVD risk may hold potential to significantly improve patient care. However, a number of questions related to the design of such 2 × 2 factorial trial still needs to be answered.

Cardiovascular Aging and Longevity: JACC State-of-the-Art Review

Cardiovascular aging and longevity are interrelated through many pathophysiological mechanisms. Many factors that promote atherosclerotic cardiovascular disease are also implicated in the aging process and vice versa. Indeed, cardiometabolic disorders such as hyperglycemia, insulin resistance, dyslipidemia, and arterial hypertension share common pathophysiological mechanisms with aging and longevity. Moreover, genetic modulators of longevity have a significant impact on cardiovascular aging. The current knowledge of genetic, molecular, and biochemical pathways of aging may serve as a substrate to introduce interventions that might delay cardiovascular aging, thus approaching the goal of longevity. In the present review, the authors describe pathophysiological links between cardiovascular aging and longevity and translate these mechanisms into clinical data by reporting genetic, dietary, and environmental characteristics from long-living populations.

Association of Diet Quality With Prevalence of Clonal Hematopoiesis and Adverse Cardiovascular Events

Importance

Clonal hematopoiesis of indeterminate potential (CHIP), the expansion of somatic leukemogenic variations in hematopoietic stem cells, has been associated with atherosclerotic cardiovascular disease. Because the inherited risk of developing CHIP is low, lifestyle elements such as dietary factors may be associated with the development and outcomes of CHIP.

Objective

To examine whether there is an association between diet quality and the prevalence of CHIP.

Design, Setting, and Participants

This retrospective cohort study used data from participants in the UK Biobank, an ongoing population-based study in the United Kingdom that examines whole-exome sequencing data and survey-based information on health-associated behaviors. Individuals from the UK Biobank were recruited between 2006 and 2010 and followed up prospectively with linkage to health data records through May 2020. The present study included 44 111 participants in the UK Biobank who were age 40 to 70 years, had data available from whole-exome sequencing of blood DNA, and were free of coronary artery disease (CAD) or hematologic cancer at baseline.

Exposures

Diet quality was categorized as unhealthy if the intake of healthy elements (fruits and vegetables) was lower than the median of all survey responses, and the intake of unhealthy elements (red meat, processed food, and added salt) was higher than the median. Diets were classified as healthy if the intake of healthy elements was higher than the median, and the intake of unhealthy elements was lower than the median. The presence of CHIP was detected by data from whole-exome sequencing of blood DNA.

Main Outcomes and Measures

The primary outcome was CHIP prevalence. Multivariable logistic regression analysis was used to examine the association between diet quality and the presence of CHIP. Multivariable Cox proportional hazards models were used to assess the association of incident events (acute coronary syndromes, coronary revascularization, or death) in each diet quality category stratified by the presence of CHIP.

Results

Among 44 111 participants (mean [SD] age at time of blood sample collection, 56.3 [8.0] years; 24 507 women [55.6%]), 2271 individuals (5.1%) had an unhealthy diet, 38 552 individuals (87.4%) had an intermediate diet, and 3288 individuals (7.5%) had a healthy diet. A total of 2507 individuals (5.7%) had CHIP, and the prevalence of CHIP decreased as diet quality improved from unhealthy (162 of 2271 participants [7.1%]) to intermediate (2177 of 38 552 participants [5.7%]) to healthy (168 of 3288 participants [5.1%]; P = .003 for trend). Compared with individuals without CHIP who had an intermediate diet, the rates of incident cardiovascular events progressively decreased among those with CHIP who had an unhealthy diet (hazard ratio [HR], 1.52; 95% CI, 1.04-2.22) and those with CHIP who had a healthy diet (HR, 0.99; 95% CI, 0.62-1.58) over a median of 10.0 years (interquartile range, 9.6-10.4 years) of follow-up.

Conclusions and Relevance

This cohort study suggests that an unhealthy diet quality may be associated with a higher prevalence of CHIP and higher rates of adverse cardiovascular events and death independent of CHIP status.

Clonal Hematopoiesis and Risk of Progression of Heart Failure With Reduced Left Ventricular Ejection Fraction

BACKGROUND

Clonal hematopoiesis driven by somatic mutations in hematopoietic cells, frequently called clonal hematopoiesis of indeterminate potential (CHIP), has been associated with adverse cardiovascular outcomes in population-based studies and in patients with ischemic heart failure (HF) and reduced left ventricular ejection fraction (LVEF). Yet, the impact of CHIP on HF progression, including nonischemic etiology, is unknown.

OBJECTIVES

The purpose of this study was to assess the clinical impact of clonal hematopoiesis on HF progression irrespective of its etiology.

METHODS

The study cohort comprised 62 patients with HF and LVEF <45% (age 74 ± 7 years, 74% men, 52% nonischemic, and LVEF 30 ± 8%). Deep sequencing was used to detect CHIP mutations with a variant allelic fraction >2% in 54 genes. Patients were followed for at least 3.5 years for various adverse events including death, HF-related death, and HF hospitalization.

RESULTS

CHIP mutations were detected in 24 (38.7%) patients, without significant differences in all-cause mortality (p = 0.151). After adjusting for risk factors, patients with mutations in either DNA methyltransferase 3 alpha (DNMT3A) or Tet methylcytosine dioxygenase 2 (TET2) exhibited accelerated HF progression in terms of death (hazard ratio [HR]: 2.79; 95% confidence interval [CI]: 1.31 to 5.92; p = 0.008), death or HF hospitalization (HR: 3.84; 95% CI: 1.84 to 8.04; p < 0.001) and HF-related death or HF hospitalization (HR: 4.41; 95% CI: 2.15 to 9.03; p < 0.001). In single gene-specific analyses, somatic mutations in DNMT3A or TET2 retained prognostic significance with regard to HF-related death or HF hospitalization (HR: 4.50; 95% CI: 2.07 to 9.74; p < 0.001, for DNMT3A mutations; HR: 3.18; 95% CI: 1.52 to 6.66; p = 0.002, for TET2 mutations). This association remained significant irrespective of ischemic/nonischemic etiology.

CONCLUSIONS

Somatic mutations that drive clonal hematopoiesis are common among HF patients with reduced LVEF and are associated with accelerated HF progression regardless of etiology.

Quantitative and Qualitative QC of Next-Generation Sequencing for Detecting Somatic Variants: An Example of Detecting Clonal Hematopoiesis of Indeterminate Potential

BACKGROUND

Because next-generation sequencing (NGS) for detecting somatic mutations has been adopted in clinical fields, both qualitative and quantitative QC of the somatic variants through whole coding regions detected by NGS is crucial. However, specific applications or guidelines, especially for quantitative QC, are currently insufficient. Our goal was to devise a practical approach for both quantitative and qualitative QC using an example of detecting clonal hematopoiesis of indeterminate potential (CHIP).

METHODS

We applied the QC scheme using commercial reference materials and in-house QC materials (IQCM) composed of haplotype map and cancer cell lines for monitoring CHIP.

RESULTS

This approach efficiently validated a customized CHIP NGS assay. Accuracy, analytical sensitivity, analytical specificity, qualitative precision (concordance), and limit of detection achieved were 99.87%, 98.53%, 100.00%, 100.00%, and 1.00%, respectively. The quantitative precision analysis also had a higher CV percentage at a lower alternative read depth (R2 = 0.749∼0.858). Use of IQCM ensured more than 100-fold reduction in the cost per run compared with that achieved using commercial reference materials.

CONCLUSION

Our approach determined the general analytical performance of NGS for detecting CHIP and recognized limitations such as lower precision at a lower level of variant burden. This approach could also be theoretically expanded to a general NGS assay for detecting somatic variants. Considering the reliable NGS results and cost-effectiveness, we propose the use of IQCM for QC of NGS assays at clinical laboratories.

Premature Menopause, Clonal Hematopoiesis, and Coronary Artery Disease in Postmenopausal Women

BACKGROUND

Premature menopause is an independent risk factor for cardiovascular disease in women, but mechanisms underlying this association remain unclear. Clonal hematopoiesis of indeterminate potential (CHIP), the age-related expansion of hematopoietic cells with leukemogenic mutations without detectable malignancy, is associated with accelerated atherosclerosis. Whether premature menopause is associated with CHIP is unknown.

METHODS

We included postmenopausal women from the UK Biobank (n=11 495) aged 40 to 70 years with whole exome sequences and from the Women's Health Initiative (n=8111) aged 50 to 79 years with whole genome sequences. Premature menopause was defined as natural or surgical menopause occurring before age 40 years. Co-primary outcomes were the presence of any CHIP and CHIP with variant allele frequency >0.1. Logistic regression tested the association of premature menopause with CHIP, adjusted for age, race, the first 10 principal components of ancestry, smoking, diabetes, and hormone therapy use. Secondary analyses considered natural versus surgical premature menopause and gene-specific CHIP subtypes. Multivariable-adjusted Cox models tested the association between CHIP and incident coronary artery disease.

RESULTS

The sample included 19 606 women, including 418 (2.1%) with natural premature menopause and 887 (4.5%) with surgical premature menopause. Across cohorts, CHIP prevalence in postmenopausal women with versus without a history of premature menopause was 8.8% versus 5.5% (P<0.001), respectively. After multivariable adjustment, premature menopause was independently associated with CHIP (all CHIP: odds ratio, 1.36 [95% 1.10-1.68]; P=0.004; CHIP with variant allele frequency >0.1: odds ratio, 1.40 [95% CI, 1.10-1.79]; P=0.007). Associations were larger for natural premature menopause (all CHIP: odds ratio, 1.73 [95% CI, 1.23-2.44]; P=0.001; CHIP with variant allele frequency >0.1: odds ratio, 1.91 [95% CI, 1.30-2.80]; P<0.001) but smaller and nonsignificant for surgical premature menopause. In gene-specific analyses, only DNMT3A CHIP was significantly associated with premature menopause. Among postmenopausal middle-aged women, CHIP was independently associated with incident coronary artery disease (hazard ratio associated with all CHIP: 1.36 [95% CI, 1.07-1.73]; P=0.012; hazard ratio associated with CHIP with variant allele frequency >0.1: 1.48 [95% CI, 1.13-1.94]; P=0.005).

CONCLUSIONS

Premature menopause, especially natural premature menopause, is independently associated with CHIP among postmenopausal women. Natural premature menopause may serve as a risk signal for predilection to develop CHIP and CHIP-associated cardiovascular disease.

Current state and future perspective of cardiovascular medicines derived from natural products

The contribution of natural products (NPs) to cardiovascular medicine has been extensively documented, and many have been used for centuries. Cardiovascular disease (CVD) is the leading cause of morbidity and mortality worldwide. Over the past 40 years, approximately 50% of newly developed cardiovascular drugs were based on NPs, suggesting that NPs provide essential skeletal structures for the discovery of novel medicines. After a period of lower productivity since the 1990s, NPs have recently regained scientific and commercial attention, leveraging the wealth of knowledge provided by multi-omics, combinatorial biosynthesis, synthetic biology, integrative pharmacology, analytical and computational technologies. In addition, as a crucial part of complementary and alternative medicine, Traditional Chinese Medicine has increasingly drawn attention as an important source of NPs for cardiovascular drug discovery. Given their structural diversity and biological activity NPs are one of the most valuable sources of drugs and drug leads. In this review, we briefly described the characteristics and classification of NPs in CVDs. Then, we provide an up to date summary on the therapeutic potential and the underlying mechanisms of action of NPs in CVDs, and the current view and future prospect of developing safer and more effective cardiovascular drugs based on NPs.

Inflammatory Cytokines and Atherosclerotic Plaque Progression. Therapeutic Implications

PURPOSE OF THE REVIEW

Inflammatory cytokines play a major role in atherosclerotic plaque progression. This review summarizes the rationale for personalized anti-inflammatory therapy.

RECENT FINDINGS

Systemic inflammatory parameters may be used to follow the clinical outcome in primary and secondary prevention. Medical therapy, both in patients with stable cardiovascular disease, or with acute events, may be tailored taking into consideration the level and course of systemic inflammatory mediators. There is significant space for improvement in primary prevention and in the treatment of patients who have suffered from severe cardiovascular events, paying attention to not only blood pressure and cholesterol levels but also including inflammatory parameters in our clinical analysis. The potential exists to alter the course of atherosclerosis with anti-inflammatory drugs. With increased understanding of the specific mechanisms that regulate the relationship between inflammation and atherosclerosis, new, more effective and specific anti-inflammatory treatment may become available.

What to tell your patient with clonal hematopoiesis and why: insights from 2 specialized clinics

Acquired genetic mutations in hematopoietic stem or progenitor cells can lead to clonal expansion and imbalanced blood cell production. Clonal hematopoiesis is exceptionally common with human aging, confers a risk of evolution to overt hematologic malignancy, and increases all-cause mortality and the risk of cardiovascular disease. The degree of risk depends on the specific mutant allele driving clonal expansion, number of mutations, mutant allele burden, and concomitant nongenetic risk factors (eg, hypertension or cigarette smoking). People with clonal hematopoiesis may come to clinical attention in a variety of ways, including during the evaluation of a possible hematologic malignancy, as an incidental discovery during molecular analysis of a nonhematologic neoplasm, after hematopoietic cell transplantation, or as a result of germline testing for inherited variants. Even though the risk of clonal progression or a cardiovascular event in an individual patient with clonal hematopoiesis may be low, the possibility of future clinical consequences may contribute to uncertainty and worry, because it is not yet known how to modify these risks. This review summarizes clinical considerations for patients with clonal hematopoiesis, including important points for hematologists to consider discussing with affected persons who may understandably be anxious about having a mutation in their blood that predisposes them to develop a malignancy, but which is significantly more likely to result in a myocardial infarction or stroke. The increasing frequency with which people with clonal hematopoiesis are discovered and the need for counseling these patients is driving many institutions to create specialized clinics. We describe our own experience with forming such clinics.

Hand in hand: intrinsic and extrinsic drivers of aging and clonal hematopoiesis

Over the past 25 years, the importance of hematopoietic stem cell (HSC) aging in overall hematopoietic and immune system health span has been appreciated. Much work has been done in model organisms to understand the intrinsic dysregulation that occurs in HSCs during aging, with the goal of identifying modifiable mechanisms that represent the proverbial "fountain of youth." Much more recently, the discovery of somatic mutations that are found to provide a selective advantage to HSCs and accumulate in the hematopoietic system during aging, termed clonal hematopoiesis (CH), inspires revisiting many of these previously defined drivers of HSC aging in the context of these somatic mutations. To truly understand these processes and develop a holistic picture of HSC aging, ongoing and future studies must include investigation of the critical changes that occur in the HSC niche or bone marrow microenvironment with aging, as increasing evidence supports that these HSC-extrinsic alterations provide necessary inflammation, signaling pathway activation or repression, and other selective pressures to favor HSC aging-associated phenotypes and CH. Here, we provide our perspectives based on the past 8 years of our own laboratory's investigations into these mechanisms and chart a path for integrative studies that, in our opinion, will provide an ideal opportunity to discover HSC and hematopoietic health span-extending interventions. This path includes examining when and how aging-associated HSC-intrinsic and HSC-extrinsic changes accumulate over time in different individuals and developing new models to track and test relevant HSC-extrinsic changes, complementary to innovative HSC lineage tracing systems that have recently been developed.

Editor-in-Chief's Top Picks From 2019

Each week, I record audio summaries for every paper in JACC, as well as an issue summary. Although this process is quite time-consuming, I have become familiar with every paper that we publish. Thus, I have personally selected the top 100 papers (both Original Investigations and Review Articles, and an occasional Editorial Comment) from the distinct specialties each year. In addition to my personal choices, I have included papers that have been the most accessed or downloaded on our websites, as well as those selected by the JACC Editorial Board members. In order to present the full breadth of this important research in a consumable fashion, we will present these abstracts in this issue of JACC, as well as most of the central illustrations, with the realization that a magnifying glass will be be needed for appropriate visualization. The highlights comprise the following sections: Basic & Translational Research, Cardiac Failure & Myocarditis, Cardiomyopathies/Congenital & Genetics, Cardio-Oncology, Coronary Disease & Interventions, Hypertension, Imaging, Metabolic & Lipid Disorders, Neurovascular Disease & Dementia, Promoting Health & Prevention, Rhythm Disorders & Thromboembolism, Valvular Heart Disease, and Vascular Medicine (1-100).

TET2 expedites coronary heart disease by promoting microRNA-126 expression and inhibiting the E2F3-PI3K-AKT axis

DNA demethylases of the ten-eleven translocation (TET) family serve as tumor suppressors in various human cancers, but their pathogenic effects in coronary heart disease (CHD) remain unclear. Here we report that TET2 is transcriptionally upregulated in CHD patients, where it shows potential as a diagnostic tool. Mechanistic investigations revealed that TET2 facilitates inflammatory responses and cardiomyocyte apoptosis in rats through demethylation of microRNA-126 (miR-126) promoter. This interaction leads to sequestration of miR-126 from its target E2F transcription factor 3 (E2F3), contributing to E2F3 suppression in CHD. Upregulation of miR-126 when TET2 was silenced restored levels of inflammatory factors and aggravated the degree of cardiac injury and cardiomyocyte apoptosis in rats. By contrast, simultaneous overexpression of E2F3 and miR-126 reduced the levels of inflammatory factors, cardiac injury, and cardiomyocyte apoptosis in rats. Also, TET2 was found to regulate the activity of the PI3K-AKT pathway through the miR-126-E2F3 axis. Our findings uncover a novel function for TET2 in facilitating the progression of CHD.

The Clinical Challenge of Clonal Hematopoiesis, a Newly Recognized Cardiovascular Risk Factor

Importance

Despite current standards of cardiovascular care, a considerable residual burden of risk remains in both primary and secondary prevention. Clonal hematopoiesis of indeterminate potential (CHIP) has recently emerged as a common, potent, age-associated, independent risk factor for myocardial infarction, stroke, heart failure events, and survival following percutaneous aortic valve intervention. The presence of CHIP results from the acquisition of somatic mutations in a small number of leukemia driver genes found in bone marrow stem cells, leading to the expansion of leukocytes clones in peripheral blood. The association between CHIP and cardiovascular disease likely involves activation of the inflammasome pathway. More common DNA sequencing identifies individuals with CHIP who then seek advice regarding management of their cardiovascular risk.

Observations

Using clinical vignettes based on real encounters, we highlight some of the diverse presentations of CHIP, ranging from incidental identification to that detected during cancer care, that have brought patients to the attention of cardiovascular practitioners. We illustrate how we have applied a consensus-based approach to the evaluation and management of cardiovascular risk in specific patients with CHIP. Since we currently lack evidence to guide the management of these individuals, we must rely on expert opinion while awaiting data to furnish a firmer foundation for our recommendations.

Conclusions and Relevance

These vignettes illustrate that the management of CHIP should involve an individualized plan based on features such as comorbidities, life expectancy, and other traditional cardiovascular risk factors. Because individuals with CHIP will increasingly seek advice from cardiovascular specialists regarding management, these examples provide a template for approaches based on a multidisciplinary perspective. The current need for reliance on expert opinion illustrates a great need for further investigation into the management of this newly recognized contributor to residual cardiovascular risk, both in patients who are apparently well and those with established cardiovascular or malignant disease.

Picking Winners and Losers: Cell Competition in Tissue Development and Homeostasis

Viable cells with reduced fitness are often eliminated by neighboring cells with greater fitness. This phenomenon, called cell competition, is an important mechanism for maintaining a high-quality population of cells in tissues. Foundational studies characterizing cellular competition and its molecular underpinnings were first carried out utilizing Drosophila as a model system. More recently, competitive behavior studies have extended into mammalian cell types. In this review, we highlight recent advances in the field, focusing on new insights into the molecular mechanisms regulating competitive behavior in various cellular contexts and in cancer. Throughout the review, we highlight new avenues to expand our understanding of the molecular underpinnings of cell competition and its role in tissue development and homeostasis.

Novel Mutations and Decreased Expression of the Epigenetic Regulator TET2 in Pulmonary Arterial Hypertension

BACKGROUND

Pulmonary arterial hypertension (PAH) is a lethal vasculopathy. Hereditary cases are associated with germline mutations in BMPR2 and 16 other genes; however, these mutations occur in <25% of patients with idiopathic PAH and are rare in PAH associated with connective tissue diseases. Preclinical studies suggest epigenetic dysregulation, including altered DNA methylation, promotes PAH. Somatic mutations of Tet-methylcytosine-dioxygenase-2 (TET2), a key enzyme in DNA demethylation, occur in cardiovascular disease and are associated with clonal hematopoiesis, inflammation, and adverse vascular remodeling. The role of TET2 in PAH is unknown.

METHODS

To test for a role of TET2, we used a cohort of 2572 cases from the PAH Biobank. Within this cohort, gene-specific rare variant association tests were performed using 1832 unrelated European patients with PAH and 7509 non-Finnish European subjects from the Genome Aggregation Database (gnomAD) as control subjects. In an independent cohort of 140 patients, we quantified TET2 expression in peripheral blood mononuclear cells. To assess causality, we investigated hemodynamic and histological evidence of PAH in hematopoietic Tet2-knockout mice.

RESULTS

We observed an increased burden of rare, predicted deleterious germline variants in TET2 in PAH patients of European ancestry (9/1832) compared with control subjects (6/7509; relative risk=6; P=0.00067). Assessing the whole cohort, 0.39% of patients (10/2572) had 12 TET2 mutations (75% predicted germline and 25% somatic). These patients had no mutations in other PAH-related genes. Patients with TET2 mutations were older (71±7 years versus 48±19 years; P<0.0001), were more unresponsive to vasodilator challenge (0/7 versus 140/1055 [13.2%]), had lower pulmonary vascular resistance (5.2±3.1 versus 10.5±7.0 Wood units; P=0.02), and had increased inflammation (including elevation of interleukin-1β). Circulating TET2 expression did not correlate with age and was decreased in >86% of PAH patients. Tet2-knockout mice spontaneously developed PAH, adverse pulmonary vascular remodeling, and inflammation, with elevated levels of cytokines, including interleukin-1β. Long-term therapy with an antibody targeting interleukin-1β blockade resulted in regression of PAH.

CONCLUSIONS

PAH is the first human disease related to potential TET2 germline mutations. Inherited and acquired abnormalities of TET2 occur in 0.39% of PAH cases. Decreased TET2 expression is ubiquitous and has potential as a PAH biomarker.

Clonal hematopoiesis driven by somatic mutations: A new player in atherosclerotic cardiovascular disease

The accumulation of acquired mutations is an inevitable consequence of the aging process, but its pathophysiological relevance has remained largely unexplored beyond cancer. Most of these mutations have little or no functional consequences, but in a few rare instances, a mutation may arise that confers a competitive advantage to a stem cell, leading to its clonal expansion. When such a mutation occurs in hematopoietic stem cells, it leads to a situation of clonal hematopoiesis, which has the potential to affect multiple tissues beyond the bone marrow, as the clonal expansion of the mutant stem cell is extended to circulating blood cells and tissue-infiltrating immune cells. Recent genomics and experimental studies have provided support to the notion that this somatic mutation-driven clonal hematopoiesis contributes to vascular inflammation and the development of atherosclerosis and related cardiovascular and cerebrovascular ischemic events. Here, we review our current understanding of this emerging cardiovascular risk modifier and the mechanisms underlying its connection to atherosclerosis development.