IL-1 Blockade in Patients With Heart Failure With Preserved Ejection Fraction

Rationale for the Use of Pirfenidone in Heart Failure With Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) is a major public health problem with growing prevalence and poor outcomes, mainly due to the lack of an effective treatment. HFpEF pathophysiology is heterogeneous and complex. Recently a “new paradigm” has been proposed, suggesting that cardiovascular and non-cardiovascular coexisting comorbidities lead to a systemic inflammatory state, perturbing the physiology of the endothelium and the perivascular environment and engaging molecular pathways that ultimately converge to myocardial fibrosis. If inflammation and fibrosis are the “fil rouge” in the heterogeneous spectrum of HFpEF, anti-fibrotic and anti-inflammatory drugs may have a role in its treatment. Pirfenidone is an orally bioavailable drug with antifibrotic and anti-inflammatory properties already approved for the treatment of idiopathic pulmonary fibrosis. Pirfenidone has been recently tested in animal models of myocardial fibrosis with promising results. Here we will review the rationale underlying the potential therapeutic effect of Pirfenidone in HFpEF.

Interleukin-1 and Systemic Sclerosis: Getting to the Heart of Cardiac Involvement

Systemic sclerosis (SSc) is rare, severe connective tissue disease characterized by endothelial and vascular damage, immune activation, and resulting in inflammation and fibrosis of skin and internal organs, including the heart. SSc is associated with high morbidity and mortality. Cardiac involvement is frequent in SSc patients, even though often asymptomatic at early stages, and represents one of the major causes of SSc-related mortality. Heart involvement has a variable clinical presentation, and its pathogenesis is not completely understood. Myocardial fibrosis is traditionally considered the immunopathologic hallmark of heart involvement in SSc. This unique histological feature is paralleled by distinctive clinical and prognostic features. The so-called "vascular hypothesis" represents the most credited hypothesis to explain myocardial fibrosis. More recently, the prominent role of an inflammatory myocardial process has been identified as a cardinal event in the evolution to fibrosis, thus also delineating an "inflammation-driven pathway to fibrosis". The pro-inflammatory cytokine interleukin (IL)-1 has an apical and cardinal role in the myocardial inflammatory cascade and in cardiac dysfunction. The primary aim of this perspective article is: to present the emerging evidence on the role of IL-1 and inflammasome in both SSc and heart inflammation, to review the complex interplay between cellular metabolism and inflammasome activation, and to discuss the rationale for targeted inhibition of IL-1 for the treatment of SSc-heart involvement, providing preliminary experimental and clinical data to support this hypothesis.

Pharmacotherapies in Heart Failure With Preserved Ejection Fraction: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Heart failure (HF) with preserved ejection fraction (HFpEF) causes significant cardiovascular morbidity and mortality. It is a growing problem in the developed world, especially, in the aging population. There is a paucity of data on the treatment of patients with HFpEF. We aimed to identify pharmacotherapies that improve peak oxygen consumption (peak VO2), cardiovascular mortality, and HF hospitalizations in patients with HFpEF.

METHODS

We conducted a systematic literature search for English studies in PubMed, EMBASE, Cochrane Central Register of Controlled Trials, Web of Science, Scopus, and Google scholar. We searched databases using terms relating to or describing HFpEF, stage C HFpEF, and diastolic HF and included only randomized controlled trials (RCTs). RevMan 5.4 (The Cochrane Collaboration, 2020, London, UK) was used for data analysis, and two independent investigators performed literature retrieval and data-extraction. We used PRISMA guidelines to report the outcomes. We included 14 articles in our systematic review and six studies in meta-analysis.

RESULTS

We calculated the pooled mean difference (MD) of peak VO2 between placebo and pharmacotherapies. Our meta-analysis showed that the peak VO2 was comparable between pharmacotherapies and placebo in HFpEF (MD = 0.09, 95% CI: -0.11, 0.30, I2 =28%). Our systematic review highlights that statins and spironolactone use should be further studied in larger RCTs due to their potential beneficial effect on all-cause mortality and hospitalizations, respectively.

CONCLUSION

Compared to placebo, none of the pharmacotherapies significantly improved peak VO2 in HFpEF except ivabradine. In our meta-analysis, the pooled improvement in peak VO2 is non-significant. This needs validation with larger studies. We are lacking larger studies on pharmacotherapies that improve peak VO2 in HFpEF. Statin and spironolactone should be further studied in patients with HFpEF as few trials have shown improvement in all-cause mortality and reduction in HF hospitalizations in selected patients, respectively.

NLRP3 Inflammasome Inhibitors in Cardiovascular Diseases

Virtually all types of cardiovascular diseases are associated with pathological activation of the innate immune system. The NACHT, leucine-rich repeat (LRR), and pyrin domain (PYD)-containing protein 3 (NLRP3) inflammasome is a protein complex that functions as a platform for rapid induction of the inflammatory response to infection or sterile injury. NLRP3 is an intracellular sensor that is sensitive to danger signals, such as ischemia and extracellular or intracellular alarmins during tissue injury. The NLRP3 inflammasome is regulated by the presence of damage-associated molecular patterns and initiates or amplifies inflammatory response through the production of interleukin-1β (IL-1β) and/or IL-18. NLRP3 activation regulates cell survival through the activity of caspase-1 and gasdermin-D. The development of NLRP3 inflammasome inhibitors has opened the possibility to targeting the deleterious effects of NLRP3. Here, we examine the scientific evidence supporting a role for NLRP3 and the effects of inhibitors in cardiovascular diseases.

Immunomodulation in Heart Failure with Preserved Ejection Fraction: Current State and Future Perspectives

The heart failure (HF) epidemic is growing and approximately half of the HF patients have heart failure with preserved ejection fraction (HFpEF). HFpEF is a heterogeneous syndrome, characterized by a preserved left ventricular ejection fraction (LVEF ≥ 50%) with diastolic dysfunction, and is associated with high morbidity and mortality. Underlying comorbidities of HFpEF, i.e., hypertension, type 2 diabetes mellitus, obesity, and renal failure, lead to a systemic pro-inflammatory state, thereby affecting normal cardiac function. Increased inflammatory biomarkers predict incident HFpEF and are higher in patients with HFpEF as compared with heart failure with reduced ejection fraction (HFrEF). Randomized trials in HFpEF patients using traditional HF medication failed to demonstrate a clear benefit on hard endpoints (mortality and/or HF hospitalization). Therefore, therapies targeting underlying comorbidities and systemic inflammation in early HFpEF may provide better opportunities. Here, we provide an overview of the current state and future perspectives of immunomodulatory therapies for HFpEF.

Shah K, Medina de Chazal H, Chiabrando JG, Vecchié A, Dell M, L. Mihalick V, Bogaev R, Hart L, Van Tassell BW, Arena R, Celi FS, Abbate A. The effects of canagliflozin compared to sitagliptin on cardiorespiratory fitness in type 2 diabetes mellitus and heart failure with reduced ejection fraction: The CANA-HF study

BACKGROUND

Canagliflozin reduces hospitalizations for heart failure (HF) in type 2 diabetes mellitus (T2DM). Its effect on cardiorespiratory fitness and cardiac function in patients with established HF with reduced ejection fraction (HFrEF) is unknown.

METHODS

We conducted a double-blind randomized controlled trial of canagliflozin 100 mg or sitagliptin 100 mg daily for 12 weeks in 88 patients, and measured peak oxygen consumption (VO₂ ) and minute ventilation/carbon dioxide production (VE/VCO₂ ) slope (co-primary endpoints for repeated measure ANOVA time_x_group interaction), lean peak VO₂ , ventilatory anaerobic threshold (VAT), cardiac function and quality of life (ie, Minnesota Living with Heart Failure Questionnaire [MLHFQ]), at baseline and 12-week follow-up.

RESULTS

The study was terminated early due to the new guidelines recommending canagliflozin over sitagliptin in HF: 17 patients were assigned to canagliflozin and 19 to sitagliptin, total of 36 patients. There were no significant changes in peak VO₂ and VE/VCO₂ slope between the two groups (P = .083 and P = .98, respectively). Canagliflozin improved lean peak VO₂ (+2.4 mL kg_LM^-1 min^-1 , P = .036), VAT (+1.5 mL kg^-1 min^-1 , P = .012) and VO₂ matched for respiratory exchange ratio (+2.4 mL Kg^-1 min^-1 , P = .002) compared to sitagliptin. Canagliflozin also reduced MLHFQ score (-12.1, P = .018).

CONCLUSIONS

In this small and short-term study of patients with T2DM and HFrEF, interrupted early after only 36 patients, canagliflozin did not improve the primary endpoints of peak VO₂ or VE/VCO₂ slope compared to sitagliptin, while showing favourable trends observed on several additional surrogate endpoints such as lean peak VO₂ , VAT and quality of life.

Phase 1B, Randomized, Double-Blinded, Dose Escalation, Single-Center, Repeat Dose Safety and Pharmacodynamics Study of the Oral NLRP3 Inhibitor Dapansutrile in Subjects With NYHA II-III Systolic Heart Failure

ABSTRACT

The NLRP3 inflammasome has been implicated in the development and progression of heart failure. The aim of this study was to determine the safety of an oral inhibitor of the NLRP3 inflammasome, dapansutrile (OLT1177), in patients with heart failure and reduced ejection fraction (HFrEF). This was a phase 1B, randomized, double-blind, dose escalation, single-center, repeat dose safety and pharmacodynamics study of dapansutrile in stable patients with HFrEF (New York Heart Association Class II-III). Subjects were randomized to treatment with dapansutrile for up to 14 days at a ratio of 4:1 into 1 of 3 sequential ascending dose cohorts (500, 1000, or 2000 mg) each including 10 patients. Subjects underwent clinical assessment, biomarker determination, transthoracic echocardiogram, and maximal cardiopulmonary exercise testing at baseline, day 14, and day 28 to ascertain changes in clinical status. Placebo cases (N = 2 per cohort) were used as a decoy to reduce bias and not for statistical comparisons. Thirty participants (20 men) were treated for 13 (12-14) days. No serious adverse events during the study were recorded. All clinical or laboratory parameters at day 14 compared with baseline suggested clinical stability without significant within-group differences in the dapansutrile-pooled group or the 3 dapansutrile cohorts. Improvements in left ventricular EF [from 31.5% (27.5-39) to 36.5% (27.5-45), P = 0.039] and in exercise time [from 570 (399.5-627) to 616 (446.5-688) seconds, P = 0.039] were seen in the dapansutrile 2000 mg cohort. Treatment with dapansutrile for 14 days was safe and well tolerated in patients with stable HFrEF.

Evidences of CTLA-4 and PD-1 Blocking Agents-Induced Cardiotoxicity in Cellular and Preclinical Models

Background: Several strategies based on immune checkpoint inhibitors (ICIs) have been developed for cancer therapy, opening to advantages in cancer outcomes. However, several ICI-induced side effects have emerged in these patients, especially a rare but clinically significant cardiotoxicity with high rate of mortality. We studied the cytotoxic and pro-inflammatory properties of Ipilimumab and Nivolumab, the underlying pathways and cytokine storm involved. Methods: Co-cultures of human cardiomyocytes and lymphocytes were exposed to Ipilimumab or Nivolumab; cell viability and expression of leukotrienes, NLRP3, MyD88, and p65/NF-kB were performed. C57 mice were treated with Ipilimumab (15 mg/kg); analysis of fractional shortening, ejection fraction, radial and longitudinal strain were made before and after treatments through 2D-echocardiography. Expression of NLRP3, MyD88, p65/NF-kB, and 12 cytokines were analyzed in murine myocardium. Results: Nivolumab and Ipilimumab exert effective anticancer, but also significant cardiotoxic effects in co-cultures of lymphocytes and tumor or cardiac cells. Both ICIs increased NLRP3, MyD88, and p65/NF-kB expression compared to untreated cells, however, the most pro-inflammatory and cardiotoxic effects were seen after exposure to Ipilimumab. Mice treated with Ipilimumab showed a significant decrease in fractional shortening and radial strain with respect to untreated mice, coupled with a significant increase in myocardial expression of NLRP3, MyD88, and several interleukins. Conclusions: Nivolumab and Ipilimumab exert cytotoxic effects mediated by the NLRP3/IL-1β and MyD88 pathways, leading to pro-inflammatory cytokine storm in heart tissue.

Proteomic Evaluation of the Comorbidity-Inflammation Paradigm in Heart Failure With Preserved Ejection Fraction: Results From the PROMIS-HFpEF Study

BACKGROUND

A systemic proinflammatory state has been hypothesized to mediate the association between comorbidities and abnormal cardiac structure/function in heart failure with preserved ejection fraction (HFpEF). We conducted a proteomic analysis to investigate this paradigm.

METHODS

In 228 patients with HFpEF from the multicenter PROMIS-HFpEF study (Prevalence of Microvascular Dysfunction in Heart Failure With Preserved Ejection Fraction), 248 unique circulating proteins were quantified by a multiplex immunoassay (Olink) and used to recapitulate systemic inflammation. In a deductive approach, we performed principal component analysis to summarize 47 proteins known a priori to be involved in inflammation. In an inductive approach, we performed unbiased weighted coexpression network analyses of all 248 proteins to identify clusters of proteins that overrepresented inflammatory pathways. We defined comorbidity burden as the sum of 8 common HFpEF comorbidities. We used multivariable linear regression and statistical mediation analyses to determine whether and to what extent inflammation mediates the association of comorbidity burden with abnormal cardiac structure/function in HFpEF. We also externally validated our findings in an independent cohort of 117 HFpEF cases and 30 comorbidity controls without heart failure.

RESULTS

Comorbidity burden was associated with abnormal cardiac structure/function and with principal components/clusters of inflammation proteins. Systemic inflammation was also associated with increased mitral E velocity, E/e' ratio, and tricuspid regurgitation velocity; and worse right ventricular function (tricuspid annular plane systolic excursion and right ventricular free wall strain). Inflammation mediated the association between comorbidity burden and mitral E velocity (proportion mediated 19%-35%), E/e' ratio (18%-29%), tricuspid regurgitation velocity (27%-41%), and tricuspid annular plane systolic excursion (13%) (P<0.05 for all), but not right ventricular free wall strain. TNFR1 (tumor necrosis factor receptor 1), UPAR (urokinase plasminogen activator receptor), IGFBP7 (insulin-like growth factor binding protein 7), and GDF-15 (growth differentiation factor-15) were the top individual proteins that mediated the relationship between comorbidity burden and echocardiographic parameters. In the validation cohort, inflammation was upregulated in HFpEF cases versus controls, and the most prominent inflammation protein cluster identified in PROMIS-HFpEF was also present in HFpEF cases (but not controls) in the validation cohort.

CONCLUSIONS

Proteins involved in inflammation form a conserved network in HFpEF across 2 independent cohorts and may mediate the association between comorbidity burden and echocardiographic indicators of worse hemodynamics and right ventricular dysfunction. These findings support the comorbidity-inflammation paradigm in HFpEF.

Left ventricular dysfunction in heart failure with preserved ejection fraction-molecular mechanisms and impact on right ventricular function

The current classification of heart failure (HF) based on left ventricular (LV) ejection fraction (EF) identifies a large group of patients with preserved ejection fraction (HFpEF) with significant morbidity and mortality but without prognostic benefit from current HF therapy. Co-morbidities and conditions such as arterial hypertension, diabetes mellitus, chronic kidney disease, adiposity and aging shape the clinical phenotype and contribute to mortality. LV diastolic dysfunction and LV structural remodeling are hallmarks of HFpEF, and are linked to remodeling of the cardiomyocyte and extracellular matrix. Pulmonary hypertension (PH) and right ventricular dysfunction (RVD) are particularly common in HFpEF, and mortality is up to 10-fold higher in HFpEF patients with vs. without RV dysfunction. Here, we review alterations in cardiomyocyte function (i.e., ion homeostasis, sarcomere function and cellular metabolism) associated with diastolic dysfunction and summarize the main underlying cellular pathways. The contribution and interaction of systemic and regional upstream signaling such as chronic inflammation, neurohumoral activation, and NO-cGMP-related pathways are outlined in detail, and their diagnostic and therapeutic potential is discussed in the context of preclinical and clinical studies. In addition, we summarize prevalence and pathomechanisms of RV dysfunction in the context of HFpEF and discuss mechanisms connecting LV and RV dysfunction in HFpEF. Dissecting the molecular mechanisms of LV and RV dysfunction in HFpEF may provide a basis for an improved classification of HFpEF and for therapeutic approaches tailored to the molecular phenotype.

Recently Approved and Under Investigation Drugs for Treating Patients with Heart Failure

Heart Failure (HF) represents a leading cause of morbidity and mortality worldwide. Despite the recent advances in the treatment of this condition, patients´ prognosis remains unfavorable in most cases. Sacubitril/valsartan and ivabradine have been recently approved to improve clinical outcomes in patients with HF with reduced ejection fraction. Drugs under investigation for treating patients with HF encompass many novel mechanisms including vasoactive peptides, blocking inflammatory- mediators, natriuretic peptides, selective non-steroidal mineralocorticoid-receptor antagonists, myocardial β3 adrenoreceptor agonists, inhibiting the cytochrome C/cardiolipin peroxidase complex, neuregulin-1/ErbB signaling and inhibiting late inward sodium current. The aim of this manuscript is to review the main drugs under investigation for the treatment of patients with HF and give perspectives for their implementation into clinical practice.

What Is the Role of the Inflammation in the Pathogenesis of Heart Failure?

PURPOSE OF REVIEW

In heart failure, whether it is associated with reduced or preserved ejection fraction, the immune system is activated and contributes to heart remodeling and impaired function.

RECENT FINDINGS

Studies indicate that cells of the immune system not only play a role in the pathology but are also critical regulators of heart function. Knowledge about the role of the immune system driving heart failure will lead to the development of new targets to this system, particularly in those patients that, despite the apparent wellness, relapse and worsen. In this review, we will address the diverse mechanisms that trigger inflammation and their impact on heart failure progression.

Inflammatory Cytokines and Chemokines as Therapeutic Targets in Heart Failure

Heart failure exhibits remarkable pathophysiologic heterogeneity. A large body of evidence suggests that regardless of the underlying etiology, heart failure is associated with induction of cytokines and chemokines that may contribute to the pathogenesis of adverse remodeling, and systolic and diastolic dysfunction. The pro-inflammatory cytokines tumor necrosis factor (TNF)-α, interleukin (IL)-1, and IL-6 have been extensively implicated in the pathogenesis of heart failure. Inflammatory cytokines modulate phenotype and function of all myocardial cells, suppressing contractile function in cardiomyocytes, inducing inflammatory activation in macrophages, stimulating microvascular inflammation and dysfunction, and promoting a matrix-degrading phenotype in fibroblasts. Moreover, cytokine-induced growth factor synthesis may exert chronic fibrogenic actions contributing to the pathogenesis of heart failure with preserved ejection fraction (HFpEF). In addition to their role in adverse cardiac remodeling, some inflammatory cytokines may also exert protective actions on cardiomyocytes under conditions of stress. Chemokines, such as CCL2, are also upregulated in failing hearts and may stimulate recruitment of pro-inflammatory leukocytes, promoting myocardial injury, fibrotic remodeling, and dysfunction. Although experimental evidence suggests that cytokine and chemokine targeting may hold therapeutic promise in heart failure, clinical translation remains challenging. This review manuscript summarizes our knowledge on the role of TNF-α, IL-1, IL-6, and CCL2 in the pathogenesis of heart failure, and discusses the promises and challenges of targeted anti-cytokine therapy. Dissection of protective and maladaptive cellular actions of cytokines in the failing heart, and identification of patient subsets with overactive or dysregulated myocardial inflammatory responses are required for design of successful therapeutic approaches.

Hypertension as a Road to Treatment of Heart Failure with Preserved Ejection Fraction

PURPOSE OF REVIEW

Hypertension heralds the diagnosis of heart failure (HF) with preserved ejection fraction (HFpEF) in 75-85% of cases and shares many of its adverse outcomes as well as its acute and chronic symptoms. This review provides important new data about the pathophysiology and mechanisms that connect hypertension and HFpEF as well as therapy used in both conditions.

RECENT FINDINGS

The traditional model of HFpEF pathophysiology emphasizes the role of hypertension causing increased afterload on the left ventricle (LV), leading to LV hypertrophy (LVH) and subsequent LV diastolic dysfunction. Recent work has provided valuable insights into the mechanisms underlying the transition from hypertension to HFpEF, showing that the pathophysiology extends beyond LVH and diastolic dysfunction. An evolving paradigm suggests that HFpEF is inflammatory in nature with multifactorial pathophysiology, affected by age-related changes and comorbidities. Hypertension shares many of the proinflammatory mechanisms of HFpEF. Furthermore, hypertension precedes HFpEF in the majority of cases. Because of its clinically heterogeneous nature, development of standardized therapies for HFpEF has been challenging. As there are standardized approaches to hypertension, we suggest that similar approaches be used for the treatment of HFpEF, including medical and non-medical therapies. With medical therapies, a treat-to-target blood pressure (BP) strategy could be employed, such as systolic BP < 130 mmHg. With non-medical therapies, approaches to deal with physical inactivity, obesity, and sleep apnea could be used. Due to its heterogeneity, delineation of standardized therapies for HFpEF has been challenging. Focusing on the tremendous overlap of hypertensive heart disease with HFpEF, it is proposed that approaches currently used to guide therapies for hypertension be applied to the treatment of HFpEF.

Therapeutic approaches in heart failure with preserved ejection fraction: past, present, and future

In contrast to the wealth of proven therapies for heart failure with reduced ejection fraction (HFrEF), therapeutic efforts in the past have failed to improve outcomes in heart failure with preserved ejection fraction (HFpEF). Moreover, to this day, diagnosis of HFpEF remains controversial. However, there is growing appreciation that HFpEF represents a heterogeneous syndrome with various phenotypes and comorbidities which are hardly to differentiate solely by LVEF and might benefit from individually tailored approaches. These hypotheses are supported by the recently presented PARAGON-HF trial. Although treatment with LCZ696 did not result in a significantly lower rate of total hospitalizations for heart failure and death from cardiovascular causes among HFpEF patients, subanalyses suggest beneficial effects in female patients and those with an LVEF between 45 and 57%. In the future, prospective randomized trials should focus on dedicated, well-defined subgroups based on various information such as clinical characteristics, biomarker levels, and imaging modalities. These could clarify the role of LCZ696 in selected individuals. Furthermore, sodium-glucose cotransporter-2 inhibitors have just proven efficient in HFrEF patients and are currently also studied in large prospective clinical trials enrolling HFpEF patients. In addition, several novel disease-modifying drugs that pursue different strategies such as targeting cardiac inflammation and fibrosis have delivered preliminary optimistic results and are subject of further research. Moreover, innovative device therapies may enhance management of HFpEF, but need prospective adequately powered clinical trials to confirm safety and efficacy regarding clinical outcomes. This review highlights the past, present, and future therapeutic approaches in HFpEF.

Cardiopulmonary exercise testing - refining the clinical perspective by combining assessments

INTRODUCTION

Cardiorespiratory fitness (CRF) is now established as a vital sign. Cardiopulmonary exercise testing (CPX) is the gold-standard approach to assessing CRF.

AREAS COVERED

A body of literature spanning several decades clearly supports the clinical utility of CPX in those who are apparently health and at risk for chronic disease as well as numerous patient populations. While CPX, in and of itself, is a valid and reliable clinical assessment, combining findings with other available assessments may provide a more comprehensive perspective that enhances clinical decision making and outcomes. The current review will accomplish the following: (1) define key CPX measures based upon current evidence; and (2) describe the current evidence addressing the relationships between CPX and echocardiography, serum biomarkers, and cardiovascular magnetic resonance.

EXPERT OPINION

Cardiopulmonary exercise testing provides prognostic and diagnostic information in apparently healthy individuals, those at risk for one or more chronic conditions, as well as numerous patient populations. Moreover, if the goal of an intervention is to improve one or more systems integral to the physiologic response to exercise, CPX should be considered as a central assessment to gauge therapeutic efficacy. To further refine the information obtained from CPX, combining other assessments has demonstrated promise.

Targeted anti-inflammatory therapy is a new insight for reducing cardiovascular events: A review from physiology to the clinic

Despite considerable progressions, cardiovascular disease (CVD) is still one of the major causes of mortality around the world, indicates an important and unmet clinical need. Recently, extensive studies have been performed on the role of inflammatory factors as either a major or surrogate factor in the pathophysiology of CVD. Epidemiological observations suggest the theory of the role of inflammatory mediators in the development of cardiovascular events. This may support the idea that targeted anti-inflammatory therapies, on the background of traditional validated medical therapies, can play a significant role in prevention and even reduction of cardiovascular disorders. Many randomized controlled trials have shown that drugs commonly useful for primary and secondary prevention of CVD have an anti-inflammatory mechanism. Further, many anti-inflammatory drugs are being examined because of their potential to reduce the risk of cardiovascular problems. In this study, we review the process of inflammation in the development of cardiovascular events, both in vivo and clinical evidence in immunotherapy for CVD.

Interleukin-1 and the Inflammasome as Therapeutic Targets in Cardiovascular Disease

The intracellular sensing protein termed NLRP3 (for NACHT, LRR, and PYD domains-containing protein 3) forms a macromolecular structure called the NLRP3 inflammasome. The NLRP3 inflammasome plays a major role in inflammation, particularly in the production of IL (interleukin)-1β. IL-1β is the most studied of the IL-1 family of cytokines, including 11 members, among which are IL-1α and IL-18. Here, we summarize preclinical and clinical findings supporting the key pathogenetic role of the NLRP3 inflammasome and IL-1 cytokines in the formation, progression, and complications of atherosclerosis, in ischemic (acute myocardial infarction), and nonischemic injury to the myocardium (myocarditis) and the progression to heart failure. We also review the clinically available IL-1 inhibitors, although not currently approved for cardiovascular indications, and discuss other IL-1 inhibitors, not currently approved, as well as oral NLRP3 inflammasome inhibitors currently in clinical development. Canakinumab, IL-1β antibody, prevented the recurrence of ischemic events in patients with prior acute myocardial infarction in a large phase III clinical trial, including 10 061 patients world-wide. Phase II clinical trials show promising data with anakinra, recombinant IL-1 receptor antagonist, in patients with ST-segment-elevation acute myocardial infarction or heart failure with reduced ejection fraction. Anakinra also improved outcomes in patients with pericarditis, and it is now considered standard of care as second-line treatment for patients with recurrent/refractory pericarditis. Rilonacept, a soluble IL-1 receptor chimeric fusion protein neutralizing IL-1α and IL-1β, has also shown promising results in a phase II study in recurrent/refractory pericarditis. In conclusion, there is overwhelming evidence linking the NLRP3 inflammasome and the IL-1 cytokines with the pathogenesis of cardiovascular diseases. The future will likely include targeted inhibitors to block the IL-1 isoforms, and possibly oral NLRP3 inflammasome inhibitors, across a wide spectrum of cardiovascular diseases.

The Molecular and Cellular Mechanisms Associated with a Microvascular Inflammation in the Pathogenesis of Heart Failure with Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) is a severe disease with an often unfavorable outcome. The prevalence of HFpEF continues to increase, while effective treatment options remain elusive. All the medical strategies used to improve the outcome in a heart failure with reduced ejection fraction proved ineffective in HFpEF, which was probably due to the different mechanisms of development of these two types of heart failure and the diversity of the HFpEF phenotypes. According to the current paradigm of HFpEF development, a chronic mild pro-inflammatory state causes a coronary microvascular endothelial inflammation, with further myocardial fibrosis and diastolic dysfunction progression. This inflammatory paradigm of HFpEF has been confirmed with some evidence, and suppressing the inflammation may become a novel strategy for treating and managing HFpEF. This review summarizes current concepts about a microvascular inflammation in hypertrophied myocardium and provides a translational perspective of the anti-inflammatory and immunomodulatory approaches in HFpEF.

Management of Myocarditis-Related Cardiomyopathy in Adults

Myocarditis is generally a mild and self-limited consequence of systemic infection of cardiotropic viruses. However, patients can develop a temporary or permanent impairment of cardiac function including acute cardiomyopathy with hemodynamic compromise or severe arrhythmias. In this setting, specific causes of inflammation are associated with variable risks of death and transplantation. Recent translational studies suggest that treatments tailored to specific causes of myocarditis may impact clinical outcomes when added to guideline-directed medical care. This review summarizes recent advances in translational research that influence the utility of endomyocardial biopsy for the management of inflammatory cardiomyopathies. Emerging therapies for myocarditis based on these mechanistic hypotheses are entering clinical trials and may add to the benefits of established heart failure treatment.

Atherothrombosis Prevention and Treatment with Anti-interleukin-1 Agents

PURPOSE OF REVIEW

Despite major advances in terms of prevention, diagnosis, risk-stratification, management and rehabilitation, atherosclerosis and atherothrombosis continue to have major morbidity and mortality implications worldwide. Since the unraveling of the pivotal role of inflammation in atherothrombosis pathophysiology, several focused treatments have been proposed with the ultimate goal of preventing or treating myocardial infarction, stroke, and peripheral artery disease. In particular, given the centrality of interleukin-1 (IL-1), targeted anti-IL-1 agents have attracted substantial attention and efforts. Yet, uncertainty persists on the real risk-benefit and cost-benefit balance of anti-IL-1 agents in patients with or at risk of atherothrombosis.

RECENT FINDINGS

Several trials have been recently completed on atherothrombosis prevention and treatment with anti-IL-1 agents, ranging, for instance, from the large Canakinumab Antiinflammatory Thrombosis Outcome Study (CANTOS) trial to the series of translational studies conducted within the Virginia Commonwealth University-Anakinra Remodeling Trial (VCU-ART) platform. In light of the present scoping umbrella review, it appears evident that anti-IL-1 agents can reduce systemic inflammation and improve surrogate markers of cardiac and vascular function, with potential benefits on the risk of new/worsening heart failure. One trial suggested an increased risk of major adverse events with anti-interleukin-1 agents, possibly due to a rebound phenomenon, but this was based on a post-hoc analysis of a small number of events, and it was not supported by all other pertinent trials. The CANTOS study showed a potential hazard due to an increased risk of fatal infections, but the effect size was rather small. In addition, cost issues limit the foreseeable scope of these treatment strategies in unselected patients, calling instead for more refined prescribing. The evidence base on the risk-benefit and cost-benefit profile of anti-IL-1 agents for atherothrombosis prevention and treatment has expanded substantially in the last decade. While largely dominated by the landmark CANTOS trial, effect estimates also including the VCU-ART trials suggest complex short- and long-term effects which may prove favorable in carefully selected patients with acute or chronically sustained inflammation. Conversely, more liberal use appears less promising, and further studies with currently available agents or novel ones are eagerly needed to better define their role in the era of precision molecular medicine.

Heart failure with preserved ejection fraction: Similarities and differences between women and men

The syndrome of heart failure (HF) with preserved ejection fraction (HFpEF) is now recognized to account for up to half of HF cases and is the dominant form of HF in older adults, especially women. Multiple factors conspire in this predilection of HFpEF for older women. This review will discuss the epidemiology, pathophysiology, prognosis, and treatment of HFpEF with emphasis on the similarities and differences in cardiovascular aging changes, and the differential impact of comorbidities in women versus men. Responses to pharmacologic and lifestyle interventions are also reviewed. We conclude by suggesting future directions for both prevention and treatment of this common and highly morbid cardiovascular disorder.

Sarcopenic Obesity in Heart Failure With Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) is a public health epidemic that is projected to double over the next two decades. Despite the high prevalence of HFpEF, there are currently no FDA approved therapies for health-related outcomes in this clinical syndrome making it one the greatest unmet needs in cardiovascular medicine. Aging and obesity are hallmarks of HFpEF and therefore there is a high incidence of sarcopenic obesity (SO) associated with this syndrome. The presence of SO in HFpEF patients is noteworthy as it is associated with co-morbidities, worsened cardiovascular health, hospitalizations, quality of life, and mortality. Furthermore, SO plays a central role in exercise intolerance, the most commonly reported clinical symptom of this condition. The aim of this review is to provide insights into the current knowledge pertaining to the contributing pathophysiological mechanisms and clinical outcomes associated with HFpEF-related SO. Current and prospective therapies to address SO in HFpEF, including lifestyle and pharmaceutical approaches, are discussed. The urgent need for future research aimed at better understanding the multifaceted physiological contributions to SO in HFpEF and implementing interventional strategies to specifically target SO is highlighted.

Frailty Is Intertwined With Heart Failure: Mechanisms, Prevalence, Prognosis, Assessment, and Management

Frailty, a syndrome characterized by an exaggerated decline in function and reserve of multiple physiological systems, is common in older patients with heart failure (HF) and is associated with worse clinical and patient-reported outcomes. Although several detailed assessment tools have been developed and validated in the geriatric population, they are cumbersome, not validated in patients with HF, and not commonly used in routine management of patients with HF. More recently, there has been an increasing interest in developing simple frailty screening tools that could efficiently and quickly identify frail patients with HF in routine clinical settings. As the burden and recognition of frailty in older patients with HF increase, a more comprehensive approach to management is needed that targets deficits across multiple domains, including physical function and medical, cognitive, and social domains. Such a multidomain approach is critical to address the unique, multidimensional challenges to the care of these high-risk patients and to improve their functional status, quality of life, and long-term clinical outcomes. This review discusses the burden of frailty, the conceptual underpinnings of frailty in older patients with HF, and potential strategies for the assessment, screening, and management of frailty in this vulnerable patient population.

The gut microbiota and diabetic cardiomyopathy in humans

Type 2 diabetes (DT2) increases the risk of cardiovascular events and cardiac insufficiency. This insufficiency is mostly post-ischaemic in nature, but other aetiologies are possible in this high-risk population. In patients with DT2, diabetic cardiomyopathy is a recognized cause of cardiac insufficiency secondary to chronic hyperglycaemia and myocardial lipotoxicity, which promotes cardiomyocyte hypertrophy (and, frequently, apoptosis of these cells), interstitial fibrosis and a decrease in myocardial contractile performance. Several studies have shown that diabetic cardiomyopathy is associated with modifications to the intestinal microbiota, and changes in the synthesis of bacterial metabolites and their diffusion into the host, some of which appear to have direct deleterious effects on cardiac contractility. These findings open up new perspectives for pathophysiological studies by establishing the presence of a 'microbiota-myocardium' axis and raising the possibility of innovative new treatments. Correction of intestinal dysbiosis in patients with cardiac insufficiency could, therefore, constitute an innovative therapeutic approach to cases of this disease with a poor prognosis.

The Quest for Antiinflammatory and Immunomodulatory Strategies in Heart Failure

Intensive research over the last 3 decades has unequivocally demonstrated the relevance of inflammation in heart failure (HF). Despite our current and ever increasing knowledge about inflammation, the clinical success of antiinflammatory and immunomodulatory therapies in HF is still limited. This review outlines the complexity and diversity of inflammation, its reciprocal interaction with HF, and addresses future perspectives, calling for immunomodulatory therapies that are specific for factors that activate the immune system without the risk of nonspecific immune suppression.

NLRP3 Inflammasome: A Novel Player in Metabolically Induced Inflammation-Potential Influence on the Myocardium

Metabolic and immune systems are among the most fundamental requirements for survival. Many metabolic and immune response pathways or nutrient- and pathogen-sensing systems are evolutionarily conserved throughout species. As a result, the immune response and metabolic regulation are highly integrated and the proper function of each is dependent on the other. This interaction between metabolic disturbances and the immune system has been most extensively studied in disorders related to obesity such as insulin resistance, type 2 diabetes, and nonalcoholic fatty liver disease. Metabolically induced inflammation seems also to play a role in the development and progression of atherosclerosis including its complications such as myocardial infarction (MI) and post-MI remodeling. There are several lines of evidence suggesting that NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome is a sensor of metabolic stress linking metabolic disturbances to inflammation. Here, we will discuss the role of the NLRP3 inflammasome in the pathogenesis of obesity and diabetes, 2 important risk factors for atherosclerosis and MI. We will also discuss the role of NLRP3 inflammasome in the interaction between metabolic disturbances and myocardial inflammation during MI and during metabolically induced myocardial remodeling.

Chronic Kidney Disease as a Risk Factor for Heart Failure With Preserved Ejection Fraction: A Focus on Microcirculatory Factors and Therapeutic Targets

Heart failure (HF) and chronic kidney disease (CKD) co-exist, and it is estimated that about 50% of HF patients suffer from CKD. Although studies have been performed on the association between CKD and HF with reduced ejection fraction (HFrEF), less is known about the link between CKD and heart failure with preserved ejection fraction (HFpEF). Approximately, 50% of all patients with HF suffer from HFpEF, and this percentage is projected to rise in the coming years. Therapies for HFrEF are long established and considered quite successful. In contrast, clinical trials for treatment of HFpEF have all shown negative or disputable results. This is likely due to the multifactorial character and the lack of pathophysiological knowledge of HFpEF. The typical co-existence of HFpEF and CKD is partially due to common underlying comorbidities, such as hypertension, dyslipidemia and diabetes. Macrovascular changes accompanying CKD, such as hypertension and arterial stiffening, have been described to contribute to HFpEF development. Furthermore, several renal factors have a direct impact on the heart and/or coronary microvasculature and may underlie the association between CKD and HFpEF. These factors include: (1) activation of the renin-angiotensin-aldosterone system, (2) anemia, (3) hypercalcemia, hyperphosphatemia and increased levels of FGF-23, and (4) uremic toxins. This review critically discusses the above factors, focusing on their potential contribution to coronary dysfunction, left ventricular stiffening, and delayed left ventricular relaxation. We further summarize the directions of novel treatment options for HFpEF based on the contribution of these renal drivers.

Cytokines in heart failure

The natural history of heart failure (HF) is not linear, because changes in the heart structure and function start long before the disease becomes clinically evident. Many different cytokines originating from intracardiac tissues (cardiomyocytes, cardiac endothelial cells, cardiac fibroblasts, and cardiac infiltrated immune cells) or extracardiac tissues (adipose tissue, gut, and lymphoid organs) have been identified in HF. Because the levels of circulating cytokines correlate with the development and severity of HF, these mediators may have both pathophysiological importance, through their ability to modulate inflammation, myocyte stress/stretch, myocyte injury and apoptosis, fibroblast activation and extracellular matrix remodeling, and utility as clinical predictive biomarkers. A greater understanding of the mechanisms mediated by the multifaceted network of cytokines, leading to distinct HF phenotypes (HF with reduced or preserved ejection fraction), is urgently needed for the development of new treatment strategies. In this chapter, all these issues were thoroughly discussed, pointing on the practical considerations concerning the clinical use of the cytokines as prognostic biomarkers and potential therapeutic targets in HF.

Fibroblast-specific deletion of interleukin-1 receptor-1 reduces adverse cardiac remodeling following myocardial infarction

It has been hypothesized that interleukin-1alpha (IL-1α) is released from damaged cardiomyocytes following myocardial infarction (MI) and activates cardiac fibroblasts via its receptor (IL-1R1) to drive the early stages of cardiac remodeling. This study aimed to definitively test this hypothesis using cell type-specific IL-1α and IL-1R1 knockout (KO) mouse models. A floxed Il1α mouse was created and used to generate a cardiomyocyte-specific IL-1α KO mouse line (MIL1AKO). A tamoxifen-inducible fibroblast-specific IL-1R1 hemizygous KO mouse line (FIL1R1KO) was also generated. Mice underwent experimental MI (permanent left anterior descending coronary artery ligation) and cardiac function was determined 4 weeks later by conductance pressure-volume catheter analysis. Molecular markers of remodeling were evaluated at various time points by real-time RT-PCR and histology. MIL1AKO mice showed no difference in cardiac function or molecular markers of remodeling post-MI compared with littermate controls. In contrast, FIL1R1KO mice showed improved cardiac function and reduced remodeling markers post-MI compared with littermate controls. In conclusion, these data highlight a key role for the IL-1R1/cardiac fibroblast signaling axis in regulating post-MI remodeling and provide support for the continued development of anti-IL-1 therapies for improving cardiac function after MI. Cardiomyocyte-derived IL-1α was not an important contributor to post-MI remodeling in this model.

Heart Failure With Preserved Ejection Fraction and Adipose Tissue: A Story of Two Tales

Heart failure with preserved ejection fraction (HFpEF) is characterized by signs and symptoms of heart failure in the presence of a normal left ventricular ejection fraction. Although it accounts for up to 50% of all clinical presentations of heart failure, there are no evidence-based therapies for HFpEF to reduce morbidity and mortality. Additionally there is a lack of mechanistic understanding about the pathogenesis of HFpEF. HFpEF is associated with many comorbidities (such as obesity, hypertension, type 2 diabetes, atrial fibrillation, etc.) and is coupled with both cardiac and extra-cardiac abnormalities. Large outcome trials and registries reveal that being obese is a major risk factor for HFpEF. There is increasing focus on investigating the link between obesity and HFpEF, and the role that the adipose tissue and the heart, and the circulating milieu play in development and pathogenesis of HFpEF. This review discusses features of the obese-HFpEF phenotype and highlights proposed mechanisms implicated in the inter-tissue communication between adipose tissue and the heart in obesity-associated HFpEF.

[Mechanisms of exercise intolerance in patients with heart failure and preserved ejection fraction. Part I: The role of impairments in the left heart chambers]

During exercise an increase in oxygen delivery to working muscles is achieved through well‑coordinated interaction of many organs and systems: the heart, lungs, blood vessels, skeletal muscles, and the autonomic nervous system. In heart failure with preserved left ventricular ejection fraction, all mechanisms involved in the normal exercise tolerance are impaired. In the first part of this review, the impairments of the left heart chambers are considered ‑ left ventricular diastolic dysfunction, the weakening of the contractile and chronotropic reserves, left atrium dysfunction; the possible ways of their medical correction are also presented.

An Orally Available NLRP3 Inflammasome Inhibitor Prevents Western Diet-Induced Cardiac Dysfunction in Mice

BACKGROUND

A diet rich in saturated fat and sugars (Western diet, WD) induces myocardial expression of the NLRP3 inflammasome and dysfunction in mice. We therefore hypothesized that a diet enriched with an orally available NLRP3 inflammasome inhibitor could prevent WD-induced cardiac dysfunction in mice.

METHODS

Ten-week-old CD-1 male mice were fed WD or standard diet (SD) for 8 weeks. The compound 16673-34-0, an orally active NLRP3 inhibitor, was added to the diet at a concentration of 100 mg/Kg. The plasmatic levels of the NLRP3 inflammasome inhibitor were measured. Food intake, body weight, and glucose tolerance were assessed. Cardiac systolic and diastolic functions were measured by Doppler echocardiography at baseline, 4 weeks, and 8 weeks.

RESULTS

WD induced a significant increase in body weight (+14%, P = 0.02), impaired glucose tolerance (+34%, P = 0.03), and a significant increase in isovolumetric relaxation time (+129%, P = 0.03) and reduction in left ventricular ejection fraction (-10%, P = 0.03), as compared to standard chow diet (SD). The treatment with NLRP3 inhibitor in the diet prevented cardiac systolic and diastolic dysfunction (P < 0.05 for left ventricular ejection fraction, isovolumetric relaxation time, and myocardial performance index in WD with drug vs. WD without drug), without significant changes in heart rate and metabolic parameters.

CONCLUSIONS

An orally available NLRP3 inhibitor prevented WD-induced cardiac dysfunction in obese mice.

Heart Failure With Preserved Ejection Fraction: Is Ischemia Due to Coronary Microvascular Dysfunction a Mechanistic Factor?

Heart failure with preserved ejection fraction (HFpEF) is increasing in prevalence and has no guideline-recommended therapy, related in part to a lack of mechanism. Traditionally, HFpEF was thought to be secondary to afterload overload due to systemic hypertension; however, accumulating evidence suggests that HFpEF continues to worsen despite adequate control of blood pressure. Emerging data support the suggestion that myocardial ischemia secondary to coronary microvascular dysfunction could be the new paradigm pathophysiology. Several prospective, observational cohort studies indicate that the outcomes of patients with microvascular dysfunction, after an interval of several years, are dominated by HFpEF hospitalizations. Further, the most prevalent clinical phenotype (eg older women with multiple comorbidities) of patients with HFpEF resembles those with coronary microvascular dysfunction, albeit older. In this review, we provide in-depth insight about this emerging HFpEF paradigm, discuss potential therapeutic implications of this pathophysiology, and summarize some important knowledge gaps.

Inflammatory and Molecular Pathways in Heart Failure-Ischemia, HFpEF and Transthyretin Cardiac Amyloidosis

Elevated pro-inflammatory biomarkers and cytokines are associated with morbidity and mortality in heart failure (HF). Preclinical and clinical studies have shown multiple inflammatory mechanisms causing cardiac remodeling, dysfunction and chronic failure. Therapeutics in trials targeting the immune response in heart failure and its effects did not result in evident benefits regarding clinical endpoints and mortality. This review elaborates pathways of immune cytokines in pathogenesis and worsening of heart failure in clinical and cellular settings. Besides the well-known mechanisms of immune activation and inflammation in atherosclerosis causing ischemic cardiomyopathy or myocarditis, attention is focused on other mechanisms leading to heart failure such as transthyretin (TTR) amyloidosis or heart failure with preserved ejection fraction. The knowledge of the pathogenesis in heart failure and amyloidosis on a molecular and cellular level might help to highlight new disease defining biomarkers and to lead the way to new therapeutic targets.

Obesity paradox in cardiovascular disease: where do we stand?

Obesity is associated with an increased risk of developing cardiovascular disease (CVD), particularly heart failure (HF) and coronary heart disease (CHD). The mechanisms through which obesity increases CVD risk involve changes in body composition that can affect hemodynamics and alters heart structure. Pro-inflammatory cytokines produced by the adipose tissue itself which can induce cardiac dysfunction and can promote the formation of atherosclerotic plaques. When obesity and HF or CHD coexist, individuals with class I obesity present a more favorable prognosis compared to individuals who are normal or underweight. This phenomenon has been termed the “obesity paradox.” Obesity is defined as an excess fat mass (FM), but individuals with obesity typically also present with an increased amount of lean mass (LM). The increase in LM may explain part of the obesity paradox as it is associated with improved cardiorespiratory fitness (CRF), a major determinant of clinical outcomes in the general population, but particularly in those with CVD, including HF. While increased LM is a stronger prognosticator in HF compared to FM, in patients with CHD excess FM can exert protective effects particularly when not associated with increased systemic inflammation. In the present review, we discuss the mechanisms through which obesity may increase the risk for CVD, and how it may exert protective effects in the setting of established CVD, with a focus on body composition. We also highlight the importance of measuring or estimating CRF, including body composition-adjusted measures of CRF (ie, lean peak oxygen consumption) for an improved risk status stratification in patients with CVD and finally, we discuss the potential non-pharmacologic therapeutics, such as exercise training and dietary interventions, aimed at improving CRF and perhaps clinical outcomes.