Connecting heart failure with preserved ejection fraction and renal dysfunction: the role of endothelial dysfunction and inflammation

Targets for Heart Failure With Preserved Ejection Fraction

Heart failure (HF) with preserved ejection fraction (HFPEF) is responsible for half of all HF cases and will be the most common form of HF within the next 5 years. Previous studies of pharmacological agents in HFPEF have proved neutral or negative, in part due to phenotypic heterogeneity and complex underlying mechanisms. This review summarizes the key molecular and cellular pathways characterized in HFPEF as well as current and future therapies that target these mechanisms.

Targeting Endothelial Function to Treat Heart Failure with Preserved Ejection Fraction: The Promise of Exercise Training

Although the burden of heart failure with preserved ejection fraction (HFpEF) is increasing, there is no therapy available that improves prognosis. Clinical trials using beta blockers and angiotensin converting enzyme inhibitors, cardiac-targeting drugs that reduce mortality in heart failure with reduced ejection fraction (HFrEF), have had disappointing results in HFpEF patients. A new “whole-systems” approach has been proposed for designing future HFpEF therapies, moving focus from the cardiomyocyte to the endothelium. Indeed, dysfunction of endothelial cells throughout the entire cardiovascular system is suggested as a central mechanism in HFpEF pathophysiology. The objective of this review is to provide an overview of current knowledge regarding endothelial dysfunction in HFpEF. We discuss the molecular and cellular mechanisms leading to endothelial dysfunction and the extent, presence, and prognostic importance of clinical endothelial dysfunction in different vascular beds. We also consider implications towards exercise training, a promising therapy targeting system-wide endothelial dysfunction in HFpEF.

Vitamin D receptor activation reduces inflammatory cytokines and plasma MicroRNAs in moderate chronic kidney disease - a randomized trial

BACKGROUND

Chronic kidney disease (CKD) is a major risk factor for cardiovascular disease (CVD), partly due to endothelial dysfunction and chronic inflammation. Vitamin D treatment in end stage renal disease is suggested to modulate the immune system and lead to improved outcomes. We and others have demonstrated that treatment with vitamin D or activated vitamin D analogues protects the endothelial function in less severe renal disease as well. Since the endothelial protection might be mediated by vitamin D effects on inflammation, we assessed levels of pro-inflammatory cytokines and micro RNAs (miRs) in patients with moderate CKD, treated with an active vitamin D analogue (paricalcitol).

METHODS

Thirty-six patients with moderate CKD were randomized to 12 weeks treatment with placebo, 1 μg, or 2 μg paricalcitol daily. Cytokines were measured by Milliplex 26-plex. Total RNA was isolated from plasma and miRs were determined by quantitative reverse transcription PCR analysis.

RESULTS

Selected pro-inflammatory cytokines decreased significantly following treatment, while no change was observed in the placebo group. The micro RNAs; miR 432-5p, miR 495-3p, and miR 576-5p were significantly downregulated in the active treated groups, compared to the placebo group.

CONCLUSION

Paricalcitol treatment for 12 weeks in patients with moderate CKD reduces cytokines and micro RNAs involved in atherosclerosis and inflammation. The potentially protective role of vitamin D receptor activation in the inflammatory processes regarding the long-term outcomes in CKD patients warrants further studies.

TRIAL REGISTRATION

SOLID study; NCT01204528 , April 27, 2010.

Effect of ivabradine in patients with heart failure with preserved ejection fraction: the EDIFY randomized placebo-controlled trial

AIMS

This randomized, double-blind, placebo-controlled trial assessed whether heart rate (HR) reduction with ivabradine improves cardiac function in heart failure with preserved ejection fraction (HFpEF).

METHODS AND RESULTS

The prEserveD left ventricular ejectIon fraction chronic heart Failure with ivabradine studY (EDIFY) included 179 patients in New York Heart Association (NYHA) classes II and III, in sinus rhythm, with HR of ≥70 b.p.m., NT-proBNP of ≥220 pg/mL (BNP ≥80 pg/mL) and left ventricular ejection fraction of ≥45%. Ivabradine (or placebo) was titrated to 7.5 mg b.i.d. Patients were followed for 8 months on the change and assessed for three co-primary endpoints: echo-Doppler E/e' ratio, distance on the 6-min walking test (6MWT), and plasma NT-proBNP concentration. At baseline, median E/e' was 12.8 [interquartile range (IQR): 9.9-16.3], median distance on the 6MWT was 320 m (IQR: 247-375 m), and median NT-proBNP was 375 pg/mL (IQR: 253-701 pg/mL). Baseline median HR was 75 b.p.m. (IQR: 70-107 b.p.m.). A total of 171 patients (87 in the ivabradine group, 84 in the placebo group) were evaluated for treatment efficacy. After 8 months of treatment, findings showed a median change in HR of -13.0 b.p.m. (IQR: -18.0 to -6.0 b.p.m.) in the ivabradine group and -3.5 b.p.m. (IQR: -11.5 to 3.0 b.p.m.) in the placebo group [estimated between-group difference: 7.7 b.p.m.; 90% confidence interval (CI) -10 to -5.4; P < 0.0001]. No evidence of improvement was found in any of the three co-primary endpoints. There was almost no change in median E/e' in either of the two groups [median change: +1.0 (IQR: -0.8 to 2.9) in the ivabradine group; -0.6 (IQR: -2.2 to 1.4) in the placebo group; estimated between-group difference: 1.4, 90% CI 0.3-2.5; P = 0.135]. There were no meaningful changes in the other co-primary endpoints and no apparent trends. There was no significant safety concern.

CONCLUSIONS

In patients with HFpEF, HR reduction with ivabradine did not improve outcomes. These findings do not support the use of ivabradine in HFpEF.

Biomarker Profiles in Heart Failure Patients With Preserved and Reduced Ejection Fraction

Background

Biomarkers may help us to unravel differences in the underlying pathophysiology between heart failure (HF) patients with a reduced ejection fraction (HFrEF) and a preserved ejection fraction (HFpEF). Therefore, we compared biomarker profiles to characterize pathophysiological differences between patients with HFrEF and HFpEF.

Methods and Results

We retrospectively analyzed 33 biomarkers from different pathophysiological domains (inflammation, oxidative stress, remodeling, cardiac stretch, angiogenesis, arteriosclerosis, and renal function) in 460 HF patients (21% HFpEF, left ventricular ejection fraction ≥45%) measured at discharge after hospitalization for acute HF. The association between these markers and the occurrence of all‐cause mortality and/or HF‐related rehospitalizations at 18 months was compared between patients with HFrEF and HFpEF. Patients were 70.6±11.4 years old and 37.4% were female. Patients with HFpEF were older, more often female, and had a higher systolic blood pressure. Levels of high‐sensitive C‐reactive protein were significantly higher in HFpEF, while levels of pro‐atrial‐type natriuretic peptide and N‐terminal pro‐brain natriuretic peptide were higher in HFrEF. Linear regression followed by network analyses revealed prominent inflammation and angiogenesis‐associated interactions in HFpEF and mainly cardiac stretch–associated interactions in HFrEF. The angiogenesis‐specific marker, neuropilin and the remodeling‐specific marker, osteopontin were predictive for all‐cause mortality and/or HF‐related rehospitalizations at 18 months in HFpEF, but not in HFrEF (P for interaction <0.05).

Conclusions

In HFpEF, inflammation and angiogenesis‐mediated interactions are predominantly observed, while stretch‐mediated interactions are found in HFrEF. The remodeling marker osteopontin and the angiogenesis marker neuropilin predicted outcome in HFpEF, but not in HFrEF.

Cardiorenal disease connection during post-menopause: The protective role of estrogen in uremic toxins induced microvascular dysfunction

Female gender, post-menopause, chronic kidney disease (CKD) and (CKD linked) microvascular disease are important risk factors for developing heart failure with preserved ejection fraction (HFpEF). Enhancing our understanding of the interrelation between these risk factors could greatly benefit the identification of new drug targets for future therapy. This review discusses the evidence for the protective role of estradiol (E₂) in CKD-associated microvascular disease and related HFpEF. Elevated circulating levels of uremic toxins (UTs) during CKD may act in synergy with hormonal changes during post-menopause and could lead to coronary microvascular endothelial dysfunction in HFpEF. To elucidate the molecular mechanism involved, published transcriptome datasets of indoxyl sulfate (IS), high inorganic phosphate (HP) or E₂ treated human derived endothelial cells from the NCBI Gene Expression Omnibus database were analyzed. In total, 36 genes overlapped in both IS- and HP-activated gene sets, 188 genes were increased by UTs (HP and/or IS) and decreased by E₂, and 572 genes were decreased by UTs and increased by E₂. Based on a comprehensive in silico analysis and literature studies of collected gene sets, we conclude that CKD-accumulated UTs could negatively impact renal and cardiac endothelial homeostasis by triggering extensive inflammatory responses and initiating dysregulation of angiogenesis. E₂ may protect (myo)endothelium by inhibiting UTs-induced inflammation and ameliorating UTs-related uremic bleeding and thrombotic diathesis via restored coagulation capacity and hemostasis in injured vessels.

Imaging of Myocardial Fibrosis in Patients with End-Stage Renal Disease: Current Limitations and Future Possibilities

Cardiovascular disease in patients with end-stage renal disease (ESRD) is driven by a different set of processes than in the general population. These processes lead to pathological changes in cardiac structure and function that include the development of left ventricular hypertrophy and left ventricular dilatation and the development of myocardial fibrosis. Reduction in left ventricular hypertrophy has been the established goal of many interventional trials in patients with chronic kidney disease, but a recent systematic review has questioned whether reduction of left ventricular hypertrophy improves cardiovascular mortality as previously thought. The development of novel imaging biomarkers that link to cardiovascular outcomes and that are specific to the disease processes in ESRD is therefore required. Postmortem studies of patients with ESRD on hemodialysis have shown that the extent of myocardial fibrosis is strongly linked to cardiovascular death and accurate imaging of myocardial fibrosis would be an attractive target as an imaging biomarker. In this article we will discuss the current imaging methods available to measure myocardial fibrosis in patients with ESRD, the reliability of the techniques, specific challenges and important limitations in patients with ESRD, and how to further develop the techniques we have so they are sufficiently robust for use in future clinical trials.

The association of chronic kidney disease and microalbuminuria with heart failure with preserved vs. reduced ejection fraction

AIMS

Chronic kidney disease (CKD) and microalbuminuria are associated with incident heart failure (HF), but their relative contributions to HF with preserved vs. reduced EF (HFpEF and HFrEF) are unknown. We sought to evaluate the associations of CKD and microalbuminuria with incident HF subtypes in the community-based Framingham Heart Study (FHS).

METHODS AND RESULTS

We defined CKD as glomerular filtration rate <60 mL/min/1.73 m² , and microalbuminuria as a urine albumin to creatinine ratio (UACR) ≥17 mg/g in men and ≥25 mg/g in women. We observed 754 HF events (324 HFpEF/326 HFrEF/104 unclassified) among 9889 FHS participants with serum creatinine measured (follow-up 13 ± 4 years). In Cox models adjusted for clinical risk factors, CKD (prevalence = 9%) was associated with overall HF [hazard ratio (HR) 1.24, 95% confidence interval (CI) 1.01-1.51], but was not significantly associated with individual HF subtypes. Among 2912 individuals with available UACR (follow-up 15 ± 4 years), 192 HF events (91 HFpEF/93 HFrEF/8 unclassified) occurred. Microalbuminuria (prevalence = 17%) was associated with a higher risk of overall HF (HR 1.71, 95% CI 1.25-2.34) and HFrEF (HR 2.10, 95% CI 1.35-3.26), but not HFpEF (HR 1.26, 95% CI 0.78-2.03). In cross-sectional analyses, microalbuminuria was associated with LV systolic dysfunction (odds ratio 3.19, 95% CI 1.67-6.09).

CONCLUSIONS

Microalbuminuria was associated with incident HFrEF prospectively, and with LV systolic dysfunction cross-sectionally in a community-based sample. In contrast, CKD was modestly associated with overall HF but not differentially associated with HFpEF vs. HFrEF. The mechanisms responsible for the relationship of microalbuminuria to future development of HFrEF warrant further investigation.

Advances in the pharmacotherapy of chronic heart failure with preserved ejection fraction: an ideal opportunity for precision medicine

INTRODUCTION

Heart failure with preserved ejection fraction (HFpEF), which comprises approximately 50% of all heart failure patients, is a challenging and complex clinical syndrome that is often thought to lack effective treatments. Areas covered: Despite the common mantra that HFpEF has no effective treatments, closer inspection of HFpEF clinical trials reveals that several of the drugs tested are associated with benefits in exercise capacity and quality of life, and reduction in heart failure hospitalization. Here we review major randomized controlled trials in HFpEF, focusing on renin-angiotensin-aldosterone system antagonists, organic nitrates, digoxin, beta-blockers, and phosphodiesterase-5 inhibitors. In addition, we review several classes of drugs currently in development for HFpEF such as neprilysin inhibitors, inorganic nitrates (nitrites), and soluble guanylate cyclase stimulators. Expert opinion: HFpEF should not be viewed as lacking effective treatments. While there have been no breakthrough clinical trials showing a reduction in mortality, several existing medications are likely to benefit specific subgroups of HFpEF patients. HFpEF is now well known to be a heterogeneous syndrome; thus, the clinical management of HFpEF patients and future HFpEF clinical trials will both likely require a nuanced, phenotype-specific approach instead of a one-size-fits-all tactic. Drug development for HFpEF therefore represents an exciting opportunity for personalized medicine.

The future of pleiotropic therapy in heart failure. Lessons from the benefits of exercise training on endothelial function

A novel generation of drugs is introduced in the treatment of heart failure (HF). These drugs, including phosphodiesterase-5 inhibitors, guanylate cyclase stimulators and activators, share the feature that their action is either endothelial-mediated or substitutes for endothelial pathways, in particular the nitric oxide-cyclic guanosine monophosphate pathway, thereby influencing homeostatic balances in virtually each organ system in a pleiotropic fashion. Unfortunately, recent clinical trials with some of these drugs have shown disappointing results, at least in the setting of HF with a preserved ejection fraction. This suggests that their clinical use may require approaches that diverge from traditional pharmacological approaches, the latter often titrated on the effects of drugs on haemodynamic parameters or single biomarkers. In this paper we preconize that HF drugs with an endothelial profile should be applied conform to principles of endothelial physiology and systems pharmacology. This type of drug therapy should be viewed as a systems physio-pharmacological intervention and its clinical use accustomed to systems pharmacological principles, comparable to the systemic endothelial-mediated benefits induced by exercise training in HF. We will review the actions of these drugs and define criteria to which trials with these drugs should comply in order to increase chances of success.

Dietary therapy in heart failure with preserved ejection fraction and/or left ventricular diastolic dysfunction in patients with metabolic syndrome

BACKGROUND

Heart failure is an ongoing epidemic of left ventricular (LV) dilatation and/or dysfunction due to the increasing prevalence of predisposing risk factors such as age, physical inactivity, (abdominal) obesity, and type-2-diabetes. Approximately half of these patients have diastolic heart failure (HFpEF). The prognosis of HFpEF is comparable to that of systolic heart failure, but without any known effective treatment.

DIASTOLIC DYSFUNCTION

A biomathematically corrected diagnostic approach is presented that quantifies diastolic dysfunction via the predominant age dependency of LV diastolic function and unmasks (metabolic) risk factors, that are independent of age and, therefore, potential targets for therapy. Patients with HFpEF have reduced cardiac energy reserve that is frequently caused by insulin resistance. Consequently, HFpEF and/or LV diastolic dysfunction may be regarded as a cardiac manifestation of the metabolic syndrome (MetS).

DIETARY THERAPY

Accordingly, a causal therapy for metabolically induced dysfunction aims at normalizing insulin sensitivity by improving postprandial glucose and lipid metabolism. The respective treatments include 1) weight loss induced by dietary energy restriction that is often not sustained long-term and 2) independent of weight loss, focus on carbohydrate modification in exchange for an increase in protein and fat, ideally combined with an aerobic exercise program. Hence, beneficial effects of different macronutrient compositions in the dietary therapy of the underlying MetS are discussed together with the most recently available publications and meta-analyses.

CONCLUSION

Modulation/restriction of carbohydrate intake normalizes postprandial hyperglycemic and insulinemic peaks and has been shown to improve all manifestations of the MetS and also to reduce cardiovascular risk.

Heart failure with preserved ejection fraction has a better long-term prognosis than heart failure with reduced ejection fraction in old patients in a 5-year follow-up retrospective study

BACKGROUND

The issue of whether prognosis is similar between heart failure with preserved ejection fraction (HFpEF) and heart failure with reduced ejection fraction (HFrEF) remains unresolved. Because of the problem of inconsistency in the diagnostic criteria and because there is currently no lifesaving therapy available for HFpEF, it seems to be the right time to study the outcome of a clearly defined HFpEF compared with HFrEF in contemporary heart failure (HF) therapy. This study investigates 5-year-mortality and its prognostic factors in old patients with HFpEF compared with those with HFrEF.

METHODS

This is a retrospective study. Patients hospitalized at Sahlgrenska University Hospital/Ostra for HF were consecutively included between May 2007 and April 2008. Diagnosis were reviewed and re-evaluated for each patient. The outcome measure was all-cause mortality and collected from May 2007 and 2013.

RESULTS

Mean age of the study population (n=289) was 79±7years. One third of the HF cohort had HFpEF. When adjusted for age HFrEF patients had a 42% higher 5-year mortality than HFpEF. By logistic regression analysis age, female sex, pulmonary disease, renal dysfunction, loop diuretics and aldosterone receptor antagonist were negatively associated with prognosis in HFpEF, whereas angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers (ACEi/ARBs) and Statins were positive prognostic factors. In HFrEF age, atrial fibrillation, NT-proBNP and loop diuretics were negative predictive factors, while treated hypertension, percutaneous coronary intervention, ACEi/ARBs and beta-blockers were positive factors for survival.

CONCLUSION

HFpEF proved to have a better long-term prognosis than HFrEF and a distinct prognostic risk profile.

Fluid status and outcome in patients with heart failure and preserved ejection fraction

BACKGROUND

Most heart failure with preserved ejection fraction (HFpEF) patients, at some point, present to an emergency department with typical symptoms of volume overload. Clinically, most respond well to standard diuretic therapy, sometimes at the cost of renal function. The study sought to define the prognostic significance of fluid status versus renal function in patients with HFpEF.

METHODS

One hundred sixty-two consecutive patients with HFpEF were enrolled in our prospective registry. Twelve patients with clinically overt decompensation were excluded. Fluid status at baseline was determined by bioelectrical impedance spectroscopy. The primary outcome measure was a combined end point consisting of hospitalization for heart failure and/or death for cardiac reason.

RESULTS

Mean age was 74.4±8.4years. Ninety-one (61%) patients were hypo- or normovolemic (relative fluid overload [Rel. FO] -0.7±5.7%) while 59 (39%) patients presented with fluid overload (Rel. FO 11.5±2.7%). During a median follow-up of 24.3months (interquartile range: 19.8-33.2), 34% of patients reached the combined end point. Multivariate Cox hazard analysis identified fluid overload (hazard ratio: 3.09; 95% confidence interval: 1.68-5.68; p<0.001) as an independent predictor of adverse outcome. Patients with fluid overload and normal renal function showed a worse event-free survival compared to the subgroup with normohydration and impaired renal function (log-rank: p=0.042).

CONCLUSION

HFpEF patients with measurable fluid overload face a dismal prognosis as compared to euvolemic patients. Our data, while preliminary, suggest that patients with fluid overload may face a better outcome under continued fluid removal irrespective of changes in eGFR.

Phenotype-Specific Treatment of Heart Failure With Preserved Ejection Fraction: A Multiorgan Roadmap

Heart failure (HF) with preserved ejection fraction (EF; HFpEF) accounts for 50% of HF cases, and its prevalence relative to HF with reduced EF continues to rise. In contrast to HF with reduced EF, large trials testing neurohumoral inhibition in HFpEF failed to reach a positive outcome. This failure was recently attributed to distinct systemic and myocardial signaling in HFpEF and to diversity of HFpEF phenotypes. In this review, an HFpEF treatment strategy is proposed that addresses HFpEF-specific signaling and phenotypic diversity. In HFpEF, extracardiac comorbidities such as metabolic risk, arterial hypertension, and renal insufficiency drive left ventricular remodeling and dysfunction through systemic inflammation and coronary microvascular endothelial dysfunction. The latter affects left ventricular diastolic dysfunction through macrophage infiltration, resulting in interstitial fibrosis, and through altered paracrine signaling to cardiomyocytes, which become hypertrophied and stiff because of low nitric oxide and cyclic guanosine monophosphate. Systemic inflammation also affects other organs such as lungs, skeletal muscle, and kidneys, leading, respectively, to pulmonary hypertension, muscle weakness, and sodium retention. Individual steps of these signaling cascades can be targeted by specific interventions: metabolic risk by caloric restriction, systemic inflammation by statins, pulmonary hypertension by phosphodiesterase 5 inhibitors, muscle weakness by exercise training, sodium retention by diuretics and monitoring devices, myocardial nitric oxide bioavailability by inorganic nitrate-nitrite, myocardial cyclic guanosine monophosphate content by neprilysin or phosphodiesterase 9 inhibition, and myocardial fibrosis by spironolactone. Because of phenotypic diversity in HFpEF, personalized therapeutic strategies are proposed, which are configured in a matrix with HFpEF presentations in the abscissa and HFpEF predispositions in the ordinate.