Associations of clonal hematopoiesis with recurrent vascular events and death in patients with incident ischemic stroke

Clonal hematopoiesis of indeterminate potential contributes to accelerated chronic kidney disease progression

Background

Clonal hematopoiesis of indeterminate potential (CHIP) is a common inflammatory condition of aging that causes myriad end-organ damage. We have recently shown associations for CHIP with acute kidney injury and with kidney function decline in the general population, with stronger associations for CHIP driven by mutations in genes other than DNMT3A (non- DNMT3A CHIP). Longitudinal kidney function endpoints in individuals with pre-existing chronic kidney disease (CKD) and CHIP have been examined in two previous studies, which reported conflicting findings and were limited by small sample sizes.

Methods

In this study, we examined the prospective associations between CHIP and CKD progression events in four cohorts of CKD patients (total N = 5,772). The primary outcome was a composite of 50% kidney function decline or kidney failure. The slope of eGFR decline was examined as a secondary outcome. Mendelian randomization techniques were then used to investigate potential causal effects of CHIP on eGFR decline. Finally, kidney function was assessed in adenine-fed CKD model mice having received a bone marrow transplant recapitulating Tet2 -CHIP compared to controls transplanted wild-type bone marrow.

Results

Across all cohorts, the average age was 66.4 years, the average baseline eGFR was 42.6 ml/min/1.73m 2 , and 24% had CHIP. Upon meta-analysis, non- DNMT3A CHIP was associated with a 59% higher relative risk of incident CKD progression (HR 1.59, 95% CI: 1.02-2.47). This association was more pronounced among individuals with diabetes (HR 1.29, 95% CI: 1.03-1.62) and with baseline eGFR ≥ 30 ml/min/1.73m (HR 1.80, 95% CI: 1.11-2.90). Additionally, the annualized slope of eGFR decline was steeper among non- DNMT3A CHIP carriers, relative to non-carriers (β -0.61 ± 0.31 ml/min/1.73m 2 , p = 0.04). Mendelian randomization analyses suggested a causal role for CHIP in eGFR decline among individuals with diabetes. In a dietary adenine mouse model of CKD, Tet2 -CHIP was associated with lower GFR as well as greater kidney inflammation, tubular injury, and tubulointerstitial fibrosis.

Conclusion

Non- DNMT3A CHIP is a potentially targetable novel risk factor for CKD progression.

Classical monocyte ontogeny dictates their functions and fates as tissue macrophages

Classical monocytes (CMs) are ephemeral myeloid immune cells that circulate in the blood. Emerging evidence suggests that CMs can have distinct ontogeny and originate from either granulocyte-monocyte- or monocyte-dendritic-cell progenitors (GMPs or MDPs). Here, we report surface markers that allowed segregation of murine GMP- and MDP-derived CMs, i.e., GMP-Mo and MDP-Mo, as well as their functional characterization, including fate definition following adoptive cell transfer. GMP-Mo and MDP-Mo yielded an equal increase in homeostatic CM progeny, such as blood-resident non-classical monocytes and gut macrophages; however, these cells differentially seeded various other selected tissues, including the dura mater and lung. Specifically, GMP-Mo and MDP-Mo differentiated into distinct interstitial lung macrophages, linking CM dichotomy to previously reported pulmonary macrophage heterogeneity. Collectively, we provide evidence for the existence of two functionally distinct CM subsets in the mouse that differentially contribute to peripheral tissue macrophage populations in homeostasis and following challenge.

Dynamics of clonal hematopoiesis under DNA-damaging treatment in patients with ovarian cancer

Clonal hematopoiesis (CH) driven by mutations in the DNA damage response (DDR) pathway is frequent in patients with cancer and is associated with a higher risk of therapy-related myeloid neoplasms (t-MNs). Here, we analyzed 423 serial whole blood and plasma samples from 103 patients with relapsed high-grade ovarian cancer receiving carboplatin, poly(ADP-ribose) polymerase inhibitor (PARPi) and heat shock protein 90 inhibitor (HSP90i) treatment within the phase II EUDARIO trial using error-corrected sequencing of 72 genes. DDR-driven CH was detected in 35% of patients and was associated with longer duration of prior PARPi treatment. TP53- and PPM1D-mutated clones exhibited substantially higher clonal expansion rates than DNMT3A- or TET2-mutated clones during treatment. Expansion of DDR clones correlated with HSP90i exposure across the three study arms and was partially abrogated by the presence of germline mutations related to homologous recombination deficiency. Single-cell DNA sequencing of selected samples revealed clonal exclusivity of DDR mutations, and identified DDR-mutated clones as the origin of t-MN in two investigated cases. Together, these results provide unique insights into the architecture and the preferential selection of DDR-mutated hematopoietic clones under intense DNA-damaging treatment. Specifically, PARPi and HSP90i therapies pose an independent risk for the expansion of DDR-CH in a dose-dependent manner.

Combined Effects of Clonal Hematopoiesis and Carotid Stenosis on Cardiovascular Mortality

BACKGROUND

The expansion of hematopoietic stem cells caused by acquired somatic mutations (clonal hematopoiesis [CH]) is a novel cardiovascular risk factor. The prognostic value of CH in patients with carotid atherosclerosis remains to be evaluated.

OBJECTIVES

This study assessed the prognostic significance of CH in patients with atherosclerosis as detected by ultrasound of the carotid artery.

METHODS

We applied deep sequencing of selected genomic regions within the genes DNMT3A, TET2, ASXL1, and JAK2 to screen for CH in 968 prospectively collected patients with asymptomatic carotid atherosclerosis evaluated by duplex sonography.

RESULTS

We detected clonal markers at variant allele frequency ≥2% in 133 (13.7%) of 968 patients (median age 69.2 years), with increasing prevalence at advanced age. Multivariate analyses including age and established cardiovascular risk factors revealed overall presence of CH to be significantly associated with increased risk of cardiovascular death (HR: 1.50; 95% CI: 1.12-2.00; P = 0.007), reflected also at the single gene level. The effect of CH was more pronounced in older patients and independent of the patients' inflammatory status as measured by high-sensitivity C-reactive protein. Simultaneous assessment of CH and degree of carotid stenosis revealed combined effects on cardiovascular mortality, depicted by a superior risk for patients with >50% stenosis and concomitant CH (adjusted HR: 1.60; 95% CI: 1.08-2.38; P = 0.020).

CONCLUSIONS

CH status in combination with the extent of carotid atherosclerosis jointly predict long-term mortality. Determination of CH can provide additional prognostic information in patients with asymptomatic carotid atherosclerosis.

Clonal hematopoiesis is associated with cardiovascular events in patients with stable coronary artery disease

Clonal hematopoiesis (CH) is a risk factor for atherosclerotic cardiovascular disease, but the impact of smaller clones and the effect on inflammatory parameters is largely unknown. Using ultrasensitive single-molecule molecular inversion probe sequencing, we evaluated the association between CH and a first major adverse cardiovascular event (MACE) in patients with angiographically documented stable coronary artery disease (CAD) and no history of acute ischemic events. CH was associated with an increased rate of MACE at four years follow-up. The size of the clone predicted MACE at an optimal cut-off value of 1.07% variant allele frequency (VAF). Mutation carriers had no change in monocytes subsets or cytokine production capacity but had higher levels of circulating tissue factor, matrilysin, and proteinase-activated receptor-1. Our study identified CH driver mutations with a VAF as small as 1.07% as a residual cardiovascular risk factor and identified potential biomarkers and therapeutic targets for patients with stable CAD.

Somatic mutations in aging and disease

Time always leaves its mark, and our genome is no exception. Mutations in the genome of somatic cells were first hypothesized to be the cause of aging in the 1950s, shortly after the molecular structure of DNA had been described. Somatic mutation theories of aging are based on the fact that mutations in DNA as the ultimate template for all cellular functions are irreversible. However, it took until the 1990s to develop the methods to test if DNA mutations accumulate with age in different organs and tissues and estimate the severity of the problem. By now, numerous studies have documented the accumulation of somatic mutations with age in normal cells and tissues of mice, humans, and other animals, showing clock-like mutational signatures that provide information on the underlying causes of the mutations. In this review, we will first briefly discuss the recent advances in next-generation sequencing that now allow quantitative analysis of somatic mutations. Second, we will provide evidence that the mutation rate differs between cell types, with a focus on differences between germline and somatic mutation rate. Third, we will discuss somatic mutational signatures as measures of aging, environmental exposure, and activities of DNA repair processes. Fourth, we will explain the concept of clonally amplified somatic mutations, with a focus on clonal hematopoiesis. Fifth, we will briefly discuss somatic mutations in the transcriptome and in our other genome, i.e., the genome of mitochondria. We will end with a brief discussion of a possible causal contribution of somatic mutations to the aging process.

[Heart and blood: clonal hematopoiesis]

Cardiovascular diseases are among the leading causes of death worldwide, with well-known modifiable risk factors, such as smoking, overweight, lipid metabolism disorders, lack of physical activity and high blood pressure playing a significant role. Recent studies have now identified "clonal hematopoiesis" as a novel blood-based risk factor. Clonal hematopoiesis arises from mutations in hematopoietic stem cells, which lead to the expansion of mutated blood cells. Mutated cell clones can be detected in over 40% of individuals over 50 years old, with more than 15% of those over 90 years old harboring large clones. Surprisingly, mutated cells predispose to the development of leukemia only to a minor extent, leading to the term clonal hematopoiesis of indeterminate potential (CHIP); however, it has been shown that CHIP is associated with an increased risk of cardiovascular diseases. Individuals with CHIP-associated gene mutations have an elevated risk of atherosclerotic vascular diseases, stroke and thrombosis. Patients with heart failure with reduced ejection fraction (HFrEF), whether of ischemic or non-ischemic origin and patients with heart failure with preserved ejection fraction (HFpEF) exhibit an increased number of mutated cells in the blood. The presence of CHIP mutations is linked to a poorer prognosis in patients with existing cardiovascular diseases. Future research should aim at a better understanding of the specific effects of different mutations, clone sizes and combinations to develop personalized therapeutic approaches. Various anti-inflammatory therapeutic drugs are available, which can be tested in controlled studies.

Clonal haematopoiesis, ageing and kidney disease

Clonal haematopoiesis of indeterminate potential (CHIP) is a preclinical condition wherein a sizeable proportion of an individual's circulating blood cells are derived from a single mutated haematopoietic stem cell. CHIP occurs frequently with ageing - more than 10% of individuals over 65 years of age are affected - and is associated with an increased risk of disease across several organ systems and premature death. Emerging evidence suggests that CHIP has a role in kidney health, including associations with predisposition to acute kidney injury, impaired recovery from acute kidney injury and kidney function decline, both in the general population and among those with chronic kidney disease. Beyond its direct effect on the kidney, CHIP elevates the susceptibility of individuals to various conditions that can detrimentally affect the kidneys, including cardiovascular disease, obesity and insulin resistance, liver disease, gout, osteoporosis and certain autoimmune diseases. Aberrant pro-inflammatory signalling, telomere attrition and epigenetic ageing are potential causal pathophysiological pathways and mediators that underlie CHIP-related disease risk. Experimental animal models have shown that inhibition of inflammatory cytokine signalling can ameliorate many of the pathological effects of CHIP, and assessment of the efficacy and safety of this class of medications for human CHIP-associated pathology is ongoing.

Nonpreferential but Detrimental Accumulation of Macrophages With Clonal Hematopoiesis-Driver Mutations in Cardiovascular Tissues-Brief Report

BACKGROUND

Clonal hematopoiesis of indeterminate potential (CHIP) is an acquired genetic risk factor for both leukemia and cardiovascular disease. It results in proinflammatory myeloid cells in the bone marrow and blood; however, how these cells behave in the cardiovascular tissue remains unclear. Our study aimed at investigating whether CHIP-mutated macrophages accumulate preferentially in cardiovascular tissues and examining the transcriptome of tissue macrophages from DNMT3A (DNA methyltransferase 3 alpha) or TET2 (Tet methylcytosine dioxygenase 2) mutation carriers.

METHODS

We recruited patients undergoing carotid endarterectomy or heart surgeries to screen for CHIP mutation carriers using targeted genomic sequencing. Myeloid and lymphoid cells were isolated from blood and cardiovascular tissue collected during surgeries using flow cytometry. DNA and RNA extracted from these sorted cells were subjected to variant allele frequency measurement using droplet digital polymerase chain reaction and transcriptomic profiling using bulk RNA sequencing, respectively.

RESULTS

Using droplet digital polymerase chain reaction, we detected similar variant allele frequency of CHIP in monocytes from blood and macrophages from atheromas and heart tissues, even among heart macrophages with and without CCR2 (C-C motif chemokine receptor 2) expression. Bulk RNA sequencing revealed a proinflammatory gene profile of myeloid cells from DNMT3A or TET2 mutation carriers compared with those from noncarriers.

CONCLUSIONS

Quantitatively, CHIP-mutated myeloid cells did not preferentially accumulate in cardiovascular tissues, but qualitatively, they expressed a more disease-prone phenotype.

Insights into the Molecular Mechanisms of Genetic Predisposition to Hematopoietic Malignancies: The Importance of Gene-Environment Interactions

SUMMARY

The recognition of host genetic factors underlying susceptibility to hematopoietic malignancies has increased greatly over the last decade. Historically, germline predisposition was thought to primarily affect the young. However, emerging data indicate that hematopoietic malignancies that develop in people of all ages across the human lifespan can derive from germline predisposing conditions and are not exclusively observed in younger individuals. The age at which hematopoietic malignancies manifest appears to correlate with distinct underlying biological pathways. Progression from having a deleterious germline variant to being diagnosed with overt malignancy involves complex, multistep gene-environment interactions with key external triggers, such as infection and inflammatory stimuli, driving clonal progression. Understanding the mechanisms by which predisposed clones transform under specific pressures may reveal strategies to better treat and even prevent hematopoietic malignancies from occurring.Recent unbiased genome-wide sequencing studies of children and adults with hematopoietic malignancies have revealed novel genes in which disease-causing variants are of germline origin. This paradigm shift is spearheaded by findings in myelodysplastic syndrome/acute myeloid leukemia (MDS/AML) as well as acute lymphoblastic leukemia, but it also encompasses other cancer types. Although not without challenges, the field of genetic cancer predisposition is advancing quickly, and a better understanding of the genetic basis of hematopoietic malignancies risk affects therapeutic decisions as well as genetic counseling and testing of at-risk family members.

Radon Exposure, Clonal Hematopoiesis, and Stroke Susceptibility in the Women's Health Initiative

BACKGROUND AND OBJECTIVES

Studies suggest that clonal hematopoiesis of indeterminate potential (CHIP) may increase risk of hematologic malignancy and cardiovascular disease, including stroke. However, few studies have investigated plausible environmental risk factors for CHIP such as radon, despite the climate-related increases in and documented infrequency of testing for this common indoor air pollutant.The purpose of this study was to estimate the risk of CHIP related to radon, an established environmental mutagen.

METHODS

We linked geocoded addresses of 10,799 Women's Health Initiative Trans-Omics for Precision Medicine (WHI TOPMed) participants to US Environmental Protection Agency-predicted, county-level, indoor average screening radon concentrations, categorized as follows: Zone 1 (>4 pCi/L), Zone 2 (2-4 pCi/L), and Zone 3 (<2 pCi/L). We defined CHIP as the presence of one or more leukemogenic driver mutations with variant allele frequency >0.02. We identified prevalent and incident ischemic and hemorrhagic strokes; subtyped ischemic stroke using Trial of ORG 10172 in Acute Stroke Treatment (TOAST) criteria; and then estimated radon-related risk of CHIP as an odds ratio (OR) and 95% CI using multivariable-adjusted, design-weighted logistic regression stratified by age, race/ethnicity, smoking status, and stroke type/subtype.

RESULTS

The percentages of participants with CHIP in Zones 1, 2, and 3 were 9.0%, 8.4%, and 7.7%, respectively (ptrend = 0.06). Among participants with ischemic stroke, Zones 2 and 1 were associated with higher estimated risks of CHIP relative to Zone 3: 1.39 (1.15-1.68) and 1.46 (1.15-1.87), but not among participants with hemorrhagic stroke: 0.98 (0.68-1.40) and 1.03 (0.70-1.52), or without stroke: 1.04 (0.74-1.46) and 0.95 (0.63-1.42), respectively (pinteraction = 0.03). Corresponding estimates were particularly high among TOAST-subtyped cardioembolism: 1.78 (1.30-2.47) and 1.88 (1.31-2.72), or other ischemic etiologies: 1.37 (1.06-1.78) and 1.50 (1.11-2.04), but not small vessel occlusion: 1.05 (0.74-1.49) and 1.00 (0.68-1.47), respectively (pinteraction = 0.10). Observed patterns of association among strata were insensitive to attrition weighting, ancestry adjustment, prevalent stroke exclusion, separate analysis of DNMT3A driver mutations, and substitution with 3 alternative estimates of radon exposure.

DISCUSSION

The robust elevation of radon-related risk of CHIP among postmenopausal women who develop incident cardioembolic stroke is consistent with a potential role of somatic genomic mutation in this societally burdensome form of cerebrovascular disease, although the mechanism has yet to be confirmed.

Association between clonal hematopoiesis-related gene mutations and unfavorable functional outcome in patients with large-artery atherosclerotic stroke

BACKGROUND

Clonal hematopoiesis of indeterminate potential (CHIP) is a phenomenon that characterizes individuals with somatic mutations that are related to hematologic malignancy but without hematologic abnormalities. Presence of CHIP is associated with the atherosclerotic cardiovascular disease through the activation of the interleukin 6 (IL-6) pathway; however, its role on unfavorable functional outcomes in different etiologies of ischemic stroke remains unclear. We aimed to investigate the association between CHIP-related gene mutations and unfavorable functional outcomes of ischemic stroke with different etiologies.

METHODS

We prospectively studied a cohort of 3396 stroke patients with identified etiologies, and identified CHIP and the presence of the IL6R variant (IL6R p.Asp358Ala) by whole-genome sequencing. The IL6R p.Asp358Ala coding mutation was used as a genetic inhibition for IL-6 signaling. The primary outcome was unfavorable functional outcome [(Modified Rankin Scale), mRS 2-6] at 3 months.

RESULTS

Of the 3396 patients, 110 (3.2%) were CHIP carriers and the median age was 62 years (IQR, 54.0-69.0). The CHIP increased the risk of unfavorable functional outcome among patients with hyper-inflammation status of high-sensitivity C-reactive protein (hsCRP) > median levels in patients with large-artery atherosclerosis (LAA) (OR 2.45, 95% CI 1.00-5.98, p = 0.049, pinteraction = 0.01). Presence of IL6R variant (IL6R p.Asp358Ala) could attenuate the risk of unfavorable functional outcome only in patients with CHIP (OR 0.30, 95%CI 0.12-0.76, p = 0.01, pinteraction = 0.02), and especially in LAA patients with CHIP (OR 0.1, 95%CI 0.02-0.42, p = 0.002; pinteraction = 0.001).

CONCLUSION

CHIP is associated with unfavorable functional outcomes in patients with LAA stroke and hyper-inflammation. Genetic IL-6 signaling inhibition might attenuate the risk of unfavorable functional outcomes in CHIP carriers, especially in LAA stroke patients.

Molecular and clinical aspects relevant for counseling individuals with clonal hematopoiesis of indeterminate potential

Clonal hematopoiesis of indeterminate potential (CHIP) has fascinated the medical community for some time. Discovered about a decade ago, this phenomenon links age-related alterations in hematopoiesis not only to the later development of hematological malignancies but also to an increased risk of early-onset cardiovascular disease and some other disorders. CHIP is detected in the blood and is characterized by clonally expanded somatic mutations in cancer-associated genes, predisposing to the development of hematologic neoplasms such as MDS and AML. CHIP-associated mutations often involve DNA damage repair genes and are frequently observed following prior cytotoxic cancer therapy. Genetic predisposition seems to be a contributing factor. It came as a surprise that CHIP significantly elevates the risk of myocardial infarction and stroke, and also contributes to heart failure and pulmonary hypertension. Meanwhile, evidence of mutant clonal macrophages in vessel walls and organ parenchyma helps to explain the pathophysiology. Besides aging, there are some risk factors promoting the appearance of CHIP, such as smoking, chronic inflammation, chronic sleep deprivation, and high birth weight. This article describes fundamental aspects of CHIP and explains its association with hematologic malignancies, cardiovascular disorders, and other medical conditions, while also exploring potential progress in the clinical management of affected individuals. While it is important to diagnose conditions that can lead to adverse, but potentially preventable, effects, it is equally important not to stress patients by confronting them with disconcerting findings that cannot be remedied. Individuals with diagnosed or suspected CHIP should receive counseling in a specialized outpatient clinic, where professionals from relevant medical specialties may help them to avoid the development of CHIP-related health problems. Unfortunately, useful treatments and clinical guidelines for managing CHIP are still largely lacking. However, there are some promising approaches regarding the management of cardiovascular disease risk. In the future, strategies aimed at restoration of gene function or inhibition of inflammatory mediators may become an option.

Identification of Clonal Hematopoiesis Driver Mutations through In Silico Saturation Mutagenesis

Clonal hematopoiesis (CH) is a phenomenon of clonal expansion of hematopoietic stem cells driven by somatic mutations affecting certain genes. Recently, CH has been linked to the development of a number of hematologic malignancies, cardiovascular diseases and other conditions. Although the most frequently mutated CH driver genes have been identified, a systematic landscape of the mutations capable of initiating this phenomenon is still lacking. Here, we train high-quality machine-learning models for 12 of the most recurrent CH driver genes to identify their driver mutations. These models outperform an experimental base-editing approach and expert-curated rules based on prior knowledge of the function of these genes. Moreover, their application to identify CH driver mutations across almost half a million donors of the UK Biobank reproduces known associations between CH driver mutations and age, and the prevalence of several diseases and conditions. We thus propose that these models support the accurate identification of CH across healthy individuals.

Clonal hematopoiesis and inflammation: A review of mechanisms and clinical implications

Clonal hematopoiesis (CH) is defined by the presence of somatic mutations in hematopoietic stem and progenitor cells (HSPC). CH is associated primarily with advancing age and confers an elevated risk of progression to overt hematologic malignancy and cardiovascular disease. Increasingly, CH is associated with a wide range of diseases driven by, and sequelae of, inflammation. Accordingly, there is great interest in better understanding the pathophysiologic and clinical relationship between CH, aging, and disease. Both observational and experimental findings support the concept that CH is a potential common denominator in the inflammatory outcomes of aging. However, there is also evidence that local and systemic inflammatory states promote the growth and select for CH clones. In this review, we aim to provide an up-to-date summary of the nature of the relationship between inflammation and CH, which is central to unlocking potential therapeutic opportunities to prevent progression to myeloid malignancy.

Clinical Implications and Dynamics of Clonal Hematopoiesis in Anti-CD19 CAR T-cell Treated Patients

Recent evidence revealed important interactions between clonal hematopoiesis (CH) and cellular therapies established for the treatment of hematologic malignancies. The impact of CH on safety, efficacy, and outcome of chimeric antigen receptor (CAR) T-cell therapy is currently under investigation. We analyzed 110 patients with relapsed/refractory B-cell non-Hodgkin lymphoma (n = 105) or acute lymphoblastic leukemia (ALL) (n = 5), treated with Axicabtagene-Ciloleucel (39%), Tisagenlecleucel (51%), or Brexucabtagene autoleucel (10%). Using error-corrected targeted sequencing, a high CH prevalence of 56.4% (variant allele frequency [VAF] ≥1%) at the time of CAR T-cell infusion was detected. The most frequently mutated gene was PPM1D followed by DNMT3A, TET2, ASXL1, and TP53. Variant allele frequencies were significantly lower in B and T cells compared with monocytes and granulocytes. CH did not increase the risk of CAR T-related toxicities. The incidences of cytokine release syndrome and immune effector-cell-associated neurotoxicity syndrome were similar between CHpos and CHneg patients, regardless of clone size, age, or CAR T product. Prolonged cytopenias were not associated with CH. Best overall response rates (ORRs) were numerically but not significantly higher in CHpos patients (ORR 76.7% versus 62.2%; P = 0.13). Furthermore, CH status did not predict progression-free survival or overall survival. Lastly, sequential analysis showed a modest VAF increase of 1.3% and acquisition of novel mutations within 100 days postinfusion. CH was frequent in large B-cell lymphoma/ALL patients receiving CAR T-cells but did not affect toxicity nor treatment response or outcome.

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.

Clonal Hematopoiesis of Indeterminate Potential Predicts Adverse Outcomes in Patients With Atherosclerotic Cardiovascular Disease

BACKGROUND

Clonal hematopoiesis of indeterminate potential (CHIP)-the age-related clonal expansion of blood stem cells with leukemia-associated mutations-is a novel cardiovascular risk factor. Whether CHIP remains prognostic in individuals with established atherosclerotic cardiovascular disease (ASCVD) is less clear.

OBJECTIVES

This study tested whether CHIP predicts adverse outcomes in individuals with established ASCVD.

METHODS

Individuals aged 40 to 70 years from the UK Biobank with established ASCVD and available whole-exome sequences were analyzed. The primary outcome was a composite of ASCVD events and all-cause mortality. Associations of any CHIP (variant allele fraction ≥2%), large CHIP clones (variant allele fraction ≥10%), and the most commonly mutated driver genes (DNMT3A, TET2, ASXL1, JAK2, PPM1D/TP53 [DNA damage repair genes], and SF3B1/SRSF2/U2AF1 [spliceosome genes]) with incident outcomes were compared using unadjusted and multivariable-adjusted Cox regression.

RESULTS

Of 13,129 individuals (median age: 63 years) included, 665 (5.1%) had CHIP. Over a median follow-up of 10.8 years, any CHIP and large CHIP at baseline were associated with adjusted HRs of 1.23 (95% CI: 1.10-1.38; P < 0.001) and 1.34 (95% CI: 1.17-1.53; P < 0.001), respectively, for the primary outcome. TET2 and spliceosome CHIP, especially large clones, were most strongly associated with adverse outcomes (large TET2 CHIP: HR: 1.89; 95% CI: 1.40-2.55; P <0.001; large spliceosome CHIP: HR: 3.02; 95% CI: 1.95-4.70; P < 0.001).

CONCLUSIONS

CHIP is independently associated with adverse outcomes in individuals with established ASCVD, with especially high risks observed in TET2 and SF3B1/SRSF2/U2AF1 CHIP.

Soluble Vascular Cell Adhesion Molecule-1 as an Inflammation-Related Biomarker of Coronary Slow Flow

Background: Coronary slow flow (CSF) is an angiographic entity characterized by delayed coronary opacification with no evident obstructive lesion in the epicardial coronary artery. Several studies have shown that the occurrence and development of CSF may be closely related to inflammation. Soluble vascular cell adhesion molecule-1 (sVCAM-1) is a biomarker related to inflammation. The aim of this study was to evaluate the correlation between plasma soluble VCAM-1 level and CSF occurrence and thus the predictive value of VCAM-1 for CSF. Methods: Forty-six CSF patients and thirty control subjects were enrolled. Corrected thrombolysis in myocardial infarction frame count (cTFC) was used to diagnose CSF. Functional status and quality of life were determined by the Seattle Angina Questionnaire (SAQ). Echocardiography was used to evaluate the systolic and diastolic function of the left ventricle (LV) and right ventricle (RV). The plasma levels of sVCAM-1, IL-6, and TNF-α were quantified by enzyme-linked immunosorbent assay. Results: Compared with the control group, the physical limitation score by the SAQ, the LV global longitudinal strain (GLS), mitral E, and mitral E/A decreased in patients with CSF, while the plasma IL-6 and TNF-α levels increased. The plasma sVCAM-1 level in the CSF group was significantly higher than that in the control group (186.03 ± 83.21 vs. 82.43 ± 42.12 ng/mL, p < 0.001), positively correlated with mean cTFC (r = 0.57, p < 0.001), and negatively correlated with the physical limitation score (r = −0.32, p = 0.004). Logistic regression analyses confirmed that plasma sVCAM-1 level (OR = 1.07, 95%CI: 1.03−1.11) is an independent predictor of CSF, and the receiver operating characteristic curve analysis showed that plasma sVCAM-1 levels had statistical significance in predicting CSF (area under curve = 0.88, p < 0.001). When the sVCAM-1 level was higher than 111.57 ng/mL, the sensitivity for predicting CSF was 87% and the specificity was 73%. Conclusions: Plasma sVCAM-1 level can be used to predict CSF and was associated with the clinical symptoms of patients. It may serve as a potential biomarker for CSF in the future.