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Identification of Long Noncoding RNA H19 as a New Biomarker and Therapeutic Target in Right Ventricular Failure in Pulmonary Arterial Hypertension

期刊: CIRCULATION, 2020; 142 (15)

Background: Right ventricular (RV) function is the major determinant for both functional capacity and survival in patients with pulmonary arterial hypertension (PAH). Despite the recognized clinical importance of preserving RV function, the subcellular mechanisms that govern the transition from a compensated to a decompensated state remain poorly understood and as a consequence there are no clinically established treatments for RV failure and a paucity of clinically useful biomarkers. Accumulating evidence indicates that long noncoding RNAs are powerful regulators of cardiac development and disease. Nonetheless, their implication in adverse RV remodeling in PAH is unknown. Methods: Expression of the long noncoding RNA H19 was assessed by quantitative PCR in plasma and RV from patients categorized as control RV, compensated RV or decompensated RV based on clinical history and cardiac index. The impact of H19 suppression using GapmeR was explored in 2 rat models mimicking RV failure, namely the monocrotaline and pulmonary artery banding. Echocardiographic, hemodynamic, histological, and biochemical analyses were conducted. In vitro gain- and loss-of-function experiments were performed in rat cardiomyocytes. Results: We demonstrated that H19 is upregulated in decompensated RV from PAH patients and correlates with RV hypertrophy and fibrosis. Similar findings were observed in monocrotaline and pulmonary artery banding rats. We found that silencing H19 limits pathological RV hypertrophy, fibrosis and capillary rarefaction, thus preserving RV function in monocrotaline and pulmonary artery banding rats without affecting pulmonary vascular remodeling. This cardioprotective effect was accompanied by E2F transcription factor 1-mediated upregulation of enhancer of zeste homolog 2. In vitro, knockdown of H19 suppressed cardiomyocyte hypertrophy induced by phenylephrine, while its overexpression has the opposite effect. Finally, we demonstrated that circulating H19 levels in plasma discriminate PAH patients from controls, correlate with RV function and predict long-term survival in 2 independent idiopathic PAH cohorts. Moreover, H19 levels delineate subgroups of patients with differentiated prognosis when combined with the NT-proBNP (N-terminal pro-B-type natriuretic peptide) levels or the risk score proposed by both REVEAL (Registry to Evaluate Early and Long-Term PAH Disease Management) and the 2015 European Pulmonary Hypertension Guidelines. Conclusions: Our findings identify H19 as a new therapeutic target to impede the development of maladaptive RV remodeling and a promising biomarker of PAH severity and prognosis.

Adult Basic Life Support 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations

期刊: CIRCULATION, 2020; 142 ()

This 2020 International Consensus on Cardiopulmonary Resuscitation (CPR) and Emergency Cardiovascular Care Science With Treatment Recommendations on basic life support summarizes evidence evaluations performed for 22 topics that were prioritized by the Basic Life Support Task Force of the International Liaison Committee on Resuscitation. The evidence reviews include 16 systematic reviews, 5 scoping reviews, and 1 evidence update. Per agreement within the International Liaison Committee on Resuscitation, new or revised treatment recommendations were only made after a systematic review. Systematic reviews were performed for the following topics: dispatch diagnosis of cardiac arrest, use of a firm surface for CPR, sequence for starting CPR (compressions-airway-breaths versus airway-breaths-compressions), CPR before calling for help, duration of CPR cycles, hand position during compressions, rhythm check timing, feedback for CPR quality, alternative techniques, public access automated external defibrillator programs, analysis of rhythm during chest compressions, CPR before defibrillation, removal of foreign-body airway obstruction, resuscitation care for suspected opioid-associated emergencies, drowning, and harm from CPR to victims not in cardiac arrest. The topics that resulted in the most extensive task force discussions included CPR during transport, CPR before calling for help, resuscitation care for suspected opioid-associated emergencies, feedback for CPR quality, and analysis of rhythm during chest compressions. After discussion of the scoping reviews and the evidence update, the task force prioritized several topics for new systematic reviews.

Personal-Level Protective Actions Against Particulate Matter Air Pollution Exposure: A Scientific Statement From the American Heart Association

期刊: CIRCULATION, 2020; 142 (23)

Since the publication of the last American Heart Association scientific statement on air pollution and cardiovascular disease in 2010, unequivocal evidence of the causal role of fine particulate matter air pollution (PM2.5, or particulate matter <= 2.5 mu m in diameter) in cardiovascular disease has emerged. There is a compelling case to provide the public with practical personalized approaches to reduce the health effects of PM2.5. Such interventions would be applicable not only to individuals in heavily polluted countries, high-risk or susceptible individuals living in cleaner environments, and microenvironments with higher pollution exposures, but also to those traveling to locations with high levels of PM2.5. The overarching motivation for this document is to summarize the current evidence supporting personal-level strategies to prevent the adverse cardiovascular effects of PM2.5, guide the use of the most proven/viable approaches, obviate the use of ineffective measures, and avoid unwarranted interventions. The significance of this statement relates not only to the global importance of PM2.5, but also to its focus on the most tested interventions and viable approaches directed at particulate matter air pollution. The writing group sought to provide expert consensus opinions on personal-level measures recognizing the current uncertainty and limited evidence base for many interventions. In doing so, the writing group acknowledges that its intent is to assist other agencies charged with protecting public health, without minimizing the personal choice considerations of an individual who may decide to use these interventions in the face of ongoing air pollution exposure.

CD4(+) T-Cell Endogenous Cystathionine gamma Lyase-Hydrogen Sulfide Attenuates Hypertension by Sulfhydrating Liver Kinase B1 to Promote T Regulatory Cell Differentiation and Proliferation

期刊: CIRCULATION, 2020; 142 (18)

Background: Hydrogen sulfide (H2S) has antihypertension and anti-inflammatory effects, and its endogenous-generation key enzyme cystathionine gamma lyase (CSE) is expressed in CD4(+) T cells. However, the role of CD4(+) T-cell endogenous CSE/H2S in the development of hypertension is unclear. Methods: Peripheral blood lymphocytes were isolated from hypertensive patients or spontaneously hypertensive rats, then H2S production and expression of its generation enzymes, cystathionine beta synthase and CSE, were measured to determine the major H2S generation system changes in hypertension. Mice with CSE-specific knockout in T cells (conditional knockout, by CD4(cre) mice hybridization) and CD4 null mice were generated for investigating the pathophysiological relevance of the CSE/H2S system. Results: In lymphocytes, H2S from CSE, but not cystathionine beta synthase, responded to blood pressure changes, supported by lymphocyte CSE protein changes and a negative correlation between H2S production with systolic blood pressure and diastolic blood pressure, but positive correlation with the serum level of interleukin 10 (an anti-inflammatory cytokine). Deletion of CSE in T cells elevated BP (5-8 mm Hg) under the physiological condition and exacerbated angiotensin II-induced hypertension. In keeping with hypertension, mesenteric artery dilation impaired association with arterial inflammation, an effect attributed to reduced immunoinhibitory T regulatory cell (Treg) numbers in the blood and kidney, thus causing excess CD4(+) and CD8(+) T cell infiltration in perivascular adipose tissues and kidney. CSE knockout CD4(+) T cell transfer into CD4 null mice, also showed the similar phenotypes' confirming the role of endogenous CSE/H2S action. Adoptive transfer of Tregs (to conditional knockout mice) reversed hypertension, vascular relaxation impairment, and immunocyte infiltration, which confirmed that conditional knockout-induced hypertension was attributable, in part, to the reduced Treg numbers. Mechanistically, endogenous CSE/H2S promoted Treg differentiation and proliferation by activating AMP-activated protein kinase. In part, it depended on activation of its upstream kinase, liver kinase B1, by sulfhydration to facilitate its substrate binding and phosphorylation. Conclusion: The constitutive sulfhydration of liver kinase B1 by CSE-derived H2S activates its target kinase, AMP-activated protein kinase, and promotes Treg differentiation and proliferation, which attenuates the vascular and renal immune-inflammation, thereby preventing hypertension.

Initial Invasive Versus Conservative Management of Stable Ischemic Heart Disease in Patients With a History of Heart Failure or Left Ventricular Dysfunction Insights From the ISCHEMIA Trial

期刊: CIRCULATION, 2020; 142 (18)

Background: Whether an initial invasive strategy in patients with stable ischemic heart disease and at least moderate ischemia improves outcomes in the setting of a history of heart failure (HF) or left ventricular dysfunction (LVD) when ejection fraction is >= 35% but <45% is unknown. Methods: Among 5179 participants randomized into ISCHEMIA (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches), all of whom had left ventricular ejection fraction (LVEF) >= 35%, we compared cardiovascular outcomes by treatment strategy in participants with a history of HF/LVD at baseline versus those without HF/LVD. Median follow-up was 3.2 years. Results: There were 398 (7.7%) participants with HF/LVD at baseline, of whom 177 had HF/LVEF >45%, 28 HF/LVEF 35% to 45%, and 193 LVEF 35% to 45% but no history of HF. HF/LVD was associated with more comorbidities at baseline, particularly previous myocardial infarction, stroke, and hypertension. Compared with patients without HF/LVD, participants with HF/LVD were more likely to experience a primary outcome composite of cardiovascular death, nonfatal myocardial infarction, or hospitalization for unstable angina, HF, or resuscitated cardiac arrest (4-year cumulative incidence rate, 22.7% versus 13.8%; cardiovascular death or myocardial infarction, 19.7% versus 12.3%; and all-cause death or HF, 15.0% versus 6.9%). Participants with HF/LVD randomized to the invasive versus conservative strategy had a lower rate of the primary outcome (17.2% versus 29.3%; difference in 4-year event rate, -12.1% [95% CI, -22.6 to -1.6%]), whereas those without HF/LVD did not (13.0% versus 14.6%; difference in 4-year event rate, -1.6% [95% CI, -3.8% to 0.7%]; P interaction = 0.055). A similar differential effect was seen for the primary outcome, all-cause mortality, and cardiovascular mortality when invasive versus conservative strategy-associated outcomes were analyzed with LVEF as a continuous variable for patients with and without previous HF. Conclusions: ISCHEMIA participants with stable ischemic heart disease and at least moderate ischemia with a history of HF or LVD were at increased risk for the primary outcome. In the small, high-risk subgroup with HF and LVEF 35% to 45%, an initial invasive approach was associated with better event-free survival. This result should be considered hypothesis-generating. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01471522.

Treatment of Masked Hypertension with a Chinese Herbal Formula A Randomized, Placebo-Controlled Trial

期刊: CIRCULATION, 2020; 142 (19)

BACKGROUND: Masked hypertension is associated with adverse cardiovascular outcomes. Nonetheless, no randomized controlled trials exist in the treatment of masked hypertension. The aim of this randomized, placebo-controlled trial was to investigate the efficacy and safety of blood pressure (BP)-lowering treatment with a Chinese herbal formula, gastrodia-uncaria granules, in patients with masked hypertension. METHODS: Patients with an office BP of <140/90 mm Hg and daytime ambulatory BP of 135 to 150 mm Hg systolic or 85 to 95 mm Hg diastolic were randomly assigned 1:1 to the treatment of gastrodia-uncaria granules or placebo 5 to 10 g twice daily for 4 weeks. The primary efficacy variable was the change in daytime ambulatory BP. RESULTS: At baseline, office and daytime BP of the 251 participants (mean age, 50.4 years; 53.4% men; mean body mass index 24.5 kg/m(2); and 2.8%, 1.6%, and 30.7% with cardiovascular disease, diabetes, and smoking, respectively) averaged 129/82 and 135/89 mm Hg, respectively. In the intention-to-treat analysis, daytime systolic/diastolic BP was reduced by 5.44/3.39 and 2.91/1.60 mm Hg in the gastrodia-uncaria granules and placebo groups, respectively. The between-group difference in BP reductions was significant for the daytime (2.52/1.79 mm Hg; P=0.025) and 24-hour BP (2.33/1.49 mm Hg; P=0.012), but not for the clinic and nighttime BPs (P=0.162). The per-protocol analysis in 229 patients produced similar results. Only 1 adverse event (sleepiness during the day) was reported, and no serious adverse event occurred. CONCLUSIONS: BP-lowering treatment with Chinese traditional medicine gastrodia-uncaria granules is efficacious for patients with masked hypertension.

A Unique Population of Regulatory T Cells in Heart Potentiates Cardiac Protection From Myocardial Infarction

期刊: CIRCULATION, 2020; 142 (20)

Background: Regulatory T cells (Tregs), traditionally recognized as potent suppressors of immune response, are increasingly attracting attention because of a second major function: residing in parenchymal tissues and maintaining local homeostasis. However, the existence, unique phenotype, and function of so-called tissue Tregs in the heart remain unclear. Methods: In mouse models of myocardial infarction (MI), myocardial ischemia/reperfusion injury, or cardiac cryoinjury, the dynamic accumulation of Tregs in the injured myocardium was monitored. The bulk RNA sequencing was performed to analyze the transcriptomic characteristics of Tregs from the injured myocardium after MI or ischemia/reperfusion injury. Photoconversion, parabiosis, single-cell T-cell receptor sequencing, and adoptive transfer were applied to determine the source of heart Tregs. The involvement of the interleukin-33/suppression of tumorigenicity 2 axis and Sparc (secreted acidic cysteine-rich glycoprotein), a molecule upregulated in heart Tregs, was further evaluated in functional assays. Results: We showed that Tregs were highly enriched in the myocardium of MI, ischemia/reperfusion injury, and cryoinjury mice. Transcriptomic data revealed that Tregs isolated from the injured hearts had plenty of differentially expressed transcripts in comparison with their lymphoid counterparts, including heart-draining lymphoid nodes, with a phenotype of promoting infarct repair, indicating a unique characteristic. The heart Tregs were accumulated mainly because of recruitment from the circulating Treg pool, whereas local proliferation also contributed to their expansion. Moreover, a remarkable case of repeatedly detected T-cell receptor of heart Tregs, more than that of spleen Tregs, suggests a model of clonal expansion. Besides, Helios(high)Nrp-1(high) phenotype proved the mainly thymic origin of heart Tregs, with a small contribution of phenotypic conversion of conventional CD4(+) T cells, proved by the analysis of T-cell receptor repertoires and conventional CD4(+) T cells adoptive transfer experiments. The interleukin-33/suppression of tumorigenicity 2 axis was essential for sustaining heart Treg populations. Last, we demonstrated that Sparc, which was highly expressed by heart Tregs, acted as a critical factor to protect the heart against MI by increasing collagen content and boosting maturation in the infarct zone. Conclusions: We identified and characterized a phenotypically and functionally unique population of heart Tregs that may lay the foundation to harness Tregs for cardioprotection in MI and other cardiac diseases.

Complex Arrhythmia Syndrome in a Knock-In Mouse Model Carrier of the N98S Calm1 Mutation

期刊: CIRCULATION, 2020; 142 (20)

Background: Calmodulin mutations are associated with arrhythmia syndromes in humans. Exome sequencing previously identified a de novo mutation in CALM1 resulting in a p.N98S substitution in a patient with sinus bradycardia and stress-induced bidirectional ventricular ectopy. The objectives of the present study were to determine if mice carrying the N98S mutation knocked into Calm1 replicate the human arrhythmia phenotype and to examine arrhythmia mechanisms. Methods: Mouse lines heterozygous for the Calm1(N98S) allele (Calm1(N98S/+)) were generated using CRISPR/Cas9 technology. Adult mutant mice and their wildtype littermates (Calm1(+/+)) underwent electrocardiographic monitoring. Ventricular de- and repolarization was assessed in isolated hearts using optical voltage mapping. Action potentials and whole-cell currents and [Ca2+](i), as well, were measured in single ventricular myocytes using the patch-clamp technique and fluorescence microscopy, respectively. The microelectrode technique was used for in situ membrane voltage monitoring of ventricular conduction fibers. Results: Two biologically independent knock-in mouse lines heterozygous for the Calm1(N98S) allele were generated. Calm1(N98S/+) mice of either sex and line exhibited sinus bradycardia, QT(c) interval prolongation, and catecholaminergic bidirectional ventricular tachycardia. Male mutant mice also showed QRS widening. Pharmacological blockade and activation of beta-adrenergic receptors rescued and exacerbated, respectively, the long-QT phenotype of Calm1(N98S/+) mice. Optical and electric assessment of membrane potential in isolated hearts and single left ventricular myocytes, respectively, revealed beta-adrenergically induced delay of repolarization. beta-Adrenergic stimulation increased peak density, slowed inactivation, and left-shifted the activation curve of I-Ca.L significantly more in Calm1(N98S/+) versus Calm1(+/+) ventricular myocytes, increasing late I-Ca.L in the former. Rapidly paced Calm1(N98S/+) ventricular myocytes showed increased propensity to delayed afterdepolarization-induced triggered activity, whereas in situ His-Purkinje fibers exhibited increased susceptibility for pause-dependent early afterdepolarizations. Epicardial mapping of Calm1(N98S/+) hearts showed that both reentry and focal mechanisms contribute to arrhythmogenesis. Conclusions: Heterozygosity for the Calm1(N98S) mutation is causative of an arrhythmia syndrome characterized by sinus bradycardia, QRS widening, adrenergically mediated QTc interval prolongation, and bidirectional ventricular tachycardia. beta-Adrenergically induced I-Ca.L dysregulation contributes to the long-QT phenotype. Pause-dependent early afterdepolarizations and tachycardia-induced delayed afterdepolarizations originating in the His-Purkinje network and ventricular myocytes, respectively, constitute potential sources of arrhythmia in Calm1(N98S/+) hearts.

In Vivo AAV-CRISPR/Cas9-Mediated Gene Editing Ameliorates Atherosclerosis in Familial Hypercholesterolemia

期刊: CIRCULATION, 2020; 141 (1)

Background: Mutations in low-density lipoprotein (LDL) receptor (LDLR) are one of the main causes of familial hypercholesterolemia, which induces atherosclerosis and has a high lifetime risk of cardiovascular disease. The clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 system is an effective tool for gene editing to correct gene mutations and thus to ameliorate disease. Methods: The goal of this work was to determine whether in vivo somatic cell gene editing through the CRISPR/Cas9 system delivered by adeno-associated virus (AAV) could treat familial hypercholesterolemia caused by the Ldlr mutant in a mouse model. We generated a nonsense point mutation mouse line, Ldlr(E208X), based on a relevant familial hypercholesterolemia-related gene mutation. The AAV-CRISPR/Cas9 was designed to correct the point mutation in the Ldlr gene in hepatocytes and was delivered subcutaneously into Ldlr(E208X) mice. Results: We found that homogeneous Ldlr(E208X) mice (n=6) exhibited severe atherosclerotic phenotypes after a high-fat diet regimen and that the Ldlr mutation was corrected in a subset of hepatocytes after AAV-CRISPR/Cas9 treatment, with LDLR protein expression partially restored (n=6). Compared with the control groups (n=6 each group), the AAV-CRISPR/Cas9 with targeted single guide RNA group (n=6) had significant reductions in total cholesterol, total triglycerides, and LDL cholesterol in the serum, whereas the aorta had smaller atherosclerotic plaques and a lower degree of macrophage infiltration. Conclusions: Our work shows that in vivo AAV-CRISPR/Cas9-mediated Ldlr gene correction can partially rescue LDLR expression and effectively ameliorate atherosclerosis phenotypes in Ldlr mutants, providing a potential therapeutic approach for the treatment of patients with familial hypercholesterolemia.

Increased Myocardial Stiffness in Patients With High-Risk Left Ventricular Hypertrophy The Hallmark of Stage-B Heart Failure With Preserved Ejection Fraction

期刊: CIRCULATION, 2020; 141 (2)

Background: Individuals with left ventricular hypertrophy (LVH) and elevated cardiac biomarkers in middle age are at high risk for the development of heart failure with preserved ejection fraction (HFpEF). However, it is unknown what the pathophysiological underpinnings of this high-risk state may be. We tested the hypothesis that patients with LVH and elevated cardiac biomarkers would demonstrate elevated left ventricular (LV) myocardial stiffness in comparison with healthy controls as a key marker for future HFpEF. Methods: Forty-six patients with LVH (LV septum >11 mm) and elevated cardiac biomarkers (N-terminal pro-B-type natriuretic peptide [>40 pg/mL] or troponin T [>0.6 pg/mL]) were recruited, along with 61 age- and sex-matched (by cohort) healthy controls. To define LV pressure-volume relationships, right heart catheterization and 3-dimensional echocardiography were performed while preload was manipulated using lower body negative pressure and rapid saline infusion. Results: There were significant differences in body size, blood pressure, and baseline pulmonary capillary wedge pressure between groups (eg, pulmonary capillary wedge pressure: LVH, 13.4 +/- 2.7 versus control, 11.7 +/- 1.7 mm Hg, P<0.0001). The LV was less distensible in LVH than in controls (smaller volume for the same filling pressure). When preload was expressed as transmural filling pressure (pulmonary capillary wedge pressure - right atrial pressure), LV myocardial stiffness was nearly 30% greater in LVH than in controls (LVH stiffness constant, 0.053 +/- 0.027 versus controls, 0.042 +/- 0.020, P=0.028). Conclusions: LV myocardial stiffness in patients with LVH and elevated biomarkers (stage-B HFpEF) is greater than in age- and sex-matched controls and thus appears to represent a transitional state from a normal healthy heart to HFpEF. Although the LV myocardial stiffness of patients with LVH is greater than that of healthy controls at this early stage, further studies are required to clarify whether interventions such as exercise training to improve LV compliance may prevent the full manifestation of the HFpEF syndrome in these high-risk individuals.

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