Effect of Statins on Mortality in Heart Failure With Preserved Ejection Fraction Without Coronary Artery Disease - Report From the JASPER Study

Microvascular Dysfunction across the Spectrum of Heart Failure Pathology: Pathophysiology, Clinical Features and Therapeutic Implications

Coronary microvascular dysfunction (CMD) plays a crucial role across the spectrum of heart failure (HF) pathology, contributing to disease development, progression, and outcomes. The pathophysiological mechanisms linking CMD to HF are complex and still not completely understood and include chronic inflammation, oxidative stress, and neurohormonal activation. Despite the diagnostic and prognostic relevance in patients with HF, there is no specific therapeutic strategy targeting CMD to date. Moreover, the diagnosis of this clinical condition is challenging. In this review article, we aim to discuss the different clinical pathogenetic mechanisms linking CMD to HF across the different spectra of these diseases, their prognostic relevance, and the possible therapeutic targets along with the remaining knowledge gaps in the field.

Use of Statins in Heart Failure with Preserved Ejection Fraction: Current Evidence and Perspectives

Systemic inflammation and coronary microvascular endothelial dysfunction are essential pathophysiological factors in heart failure (HF) with preserved ejection fraction (HFpEF) that support the use of statins. The pleiotropic properties of statins, such as anti-inflammatory, antihypertrophic, antifibrotic, and antioxidant effects, are generally accepted and may be beneficial in HF, especially in HFpEF. Numerous observational clinical trials have consistently shown a beneficial prognostic effect of statins in patients with HFpEF, while the results of two larger trials in patients with HFrEF have been controversial. Such differences may be related to a more pronounced impact of the pleiotropic properties of statins on the pathophysiology of HFpEF and pro-inflammatory comorbidities (arterial hypertension, diabetes mellitus, obesity, chronic kidney disease) that are more common in HFpEF. This review discusses the potential mechanisms of statin action that may be beneficial for patients with HFpEF, as well as clinical trials that have evaluated the statin effects on left ventricular diastolic function and clinical outcomes in patients with HFpEF.

Statins improve cardiac endothelial function to prevent heart failure with preserved ejection fraction through upregulating circRNA-RBCK1

Heart failure with preserved ejection fraction (HFpEF) is associated with endothelial dysfunction. We have previously reported that statins prevent endothelial dysfunction through inhibition of microRNA-133a (miR-133a). This study is to investigate the effects and the underlying mechanisms of statins on HFpEF. Here, we show that statins upregulate the expression of a circular RNA (circRNA-RBCK1) which is co-transcripted with the ring-B-box-coiled-coil protein interacting with protein kinase C-1 (RBCK1) gene. Simultaneously, statins increase activator protein 2 alpha (AP-2α) transcriptional activity and the interaction between circRNA-RBCK1 and miR-133a. Furthermore, AP-2α directly interacts with RBCK1 gene promoter in endothelial cells. In vivo, lovastatin improves diastolic function in male mice under HFpEF, which is abolished by loss function of endothelial AP-2α or circRNA-RBCK1. This study suggests that statins upregulate the AP-2α/circRNA-RBCK1 signaling to suppress miR-133a in cardiac endothelial cells and prevent diastolic dysfunction in HFpEF.

Inflammation as a therapeutic target in heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) accounts for around half of all cases of heart failure and may become the dominant type of heart failure in the near future. Unlike HF with reduced ejection fraction there are few evidence-based treatment strategies available. There is a significant unmet need for new strategies to improve clinical outcomes in HFpEF patients. Inflammation is widely thought to play a key role in HFpEF pathophysiology and may represent a viable treatment target. In this review focusing predominantly on clinical studies, we will summarise the role of inflammation in HFpEF and discuss potential therapeutic strategies targeting inflammation.

Ischemia with Nonobstructive Coronary Artery Disease and Atrial Cardiomyopathy-Two Sides of the Same Story?

Ischemia with nonobstructive coronary artery disease (INOCA) is increasingly recognized as a significant cause of angina, myocardial remodeling, and eventually heart failure (HF). Coronary microvascular dysfunction (CMD) is a major endotype of INOCA, and it is caused by structural and functional alterations of the coronary microcirculation. At the same time, atrial cardiomyopathy (ACM) defined by structural, functional, and electrical atrial remodeling has a major clinical impact due to its manifestations: atrial fibrillation (AF), atrial thrombosis, stroke, and HF symptoms. Both these pathologies share similar risk factors and have a high comorbidity burden. CMD causing INOCA and ACM frequently coexist. Thus, questions arise whether there is a potential link between these pathologies. Does CMD promote AF or the reverse? Which are the mechanisms that ultimately lead to CMD and ACM? Are both part of a systemic disease characterized by endothelial dysfunction? Lastly, which are the therapeutic strategies that can target endothelial dysfunction and improve the prognosis of patients with CMD and ACM? This review aims to address these questions by analyzing the existing body of evidence, offering further insight into the mechanisms of CMD and ACM, and discussing potential therapeutic strategies.

Systematic review and meta-analysis of the association between all-cause mortality and statin therapy in patients with preserved ejection fraction heart failure (HFpEF)

BACKGROUND

Heart failure (HF) is a growing global health burden increasing in prevalence as the average age of the population rises. HF with preserved ejection fraction (HFpEF) is defined as EF that is ≥50% and represents almost half of the population with HF.

METHODS

We conducted a systematic review and meta-analysis exploring an association between HFpEF and statin use on all-cause mortality and cardiovascular rehospitalisation. Searches were conducted in MEDLINE via Ovid, The Cochrane Library for clinical trials in CENTRAL and Embase via Ovid for articles published between 1 January 2000 and 2 July 2021. Risk of bias was assessed using the Newcastle-Ottawa Scale and evidence rated for quality using the GRADE approach.

RESULTS

A total of 19 studies were included in the review. The analysis suggests a risk reduction of 27% for the statin exposed participants compared to the statin non-exposed participants (HR 0.73, 95% CI: 0.68-0.79) with regard to all-cause mortality. There is a low level of heterogeneity (I² = 38%) associated with this result that has been accounted for by using a random effects model, however given the included studies are observational, the quality of the evidence is rated as low. Information on rehospitalisation was insufficient for determining the impact of statin use on rehospitalisations.

CONCLUSION

Our meta-analysis revealed a reduction in all-cause mortality in patients with HFpEF on statin therapy. Considering the outcomes from this meta-analysis there is a need for high level studies to provide quality evidence on the use of statins in patients with HFpEF.

Effect of Statins on All-Cause Mortality in Adults: A Systematic Review and Meta-Analysis of Propensity Score-Matched Studies

Statins are lipid-lowering medications used for the prevention of cardiovascular disease (CVD), but the pleiotropic effects of statins might be beneficial in other chronic diseases. This meta-analysis investigated the association between statin use and mortality in different chronic conditions. Eligible studies were real-world studies that compared all-cause mortality over at least 12 months between propensity score-matched statin users and non-users. Overall, 54 studies were included: 21 in CVD, 6 in chronic kidney disease, 6 in chronic inflammatory diseases, 3 in cancer, and 18 in other diseases. The risk of all-cause mortality was significantly reduced in statin users (hazard ratio: 0.72, 95% confidence interval: 0.66−0.76). The reduction in mortality risk was similar in CVD studies (0.73, 0.66−0.76) and non-CVD studies (0.70, 0.67−0.79). There were no significant differences in the risk reduction between cohorts with different diseases (p = 0.179). The greatest mortality reduction was seen in studies from Asia (0.61, 0.61−0.73) and the lowest in studies from North America (0.78, 0.73−0.83) and Australia (0.78, 0.62−0.97). There was a significant heterogeneity (I2 = 95%, tau2 = 0.029, p < 0.01). In conclusion, statin use was associated with a significantly reduced risk of all-cause mortality in real-world cohorts with CVD and non-CVD.

Epi-Drugs in Heart Failure

Unveiling the secrets of genome’s flexibility does not only foster new research in the field, but also gives rise to the exploration and development of novel epigenetic-based therapies as an approach to alleviate disease phenotypes. A better understanding of chromatin biology (DNA/histone complexes) and non-coding RNAs (ncRNAs) has enabled the development of epigenetic drugs able to modulate transcriptional programs implicated in cardiovascular diseases. This particularly applies to heart failure, where epigenetic networks have shown to underpin several pathological features, such as left ventricular hypertrophy, fibrosis, cardiomyocyte apoptosis and microvascular dysfunction. Targeting epigenetic signals might represent a promising approach, especially in patients with heart failure with preserved ejection fraction (HFpEF), where prognosis remains poor and breakthrough therapies have yet to be approved. In this setting, epigenetics can be employed for the development of customized therapeutic approaches thus paving the way for personalized medicine. Even though the beneficial effects of epi-drugs are gaining attention, the number of epigenetic compounds used in the clinical practice remains low suggesting that more selective epi-drugs are needed. From DNA-methylation changes to non-coding RNAs, we can establish brand-new regulations for drug targets with the aim of restoring healthy epigenomes and transcriptional programs in the failing heart. In the present review, we bring the timeline of epi-drug discovery and development, thus highlighting the emerging role of epigenetic therapies in heart failure.

Therapeutic Approaches in Heart Failure with Preserved Ejection Fraction (HFpEF) in Children: Present and Future

For a long time, pediatric heart failure (HF) with preserved systolic function (HFpEF) has been noted in patients with cardiomyopathies and congenital heart disease. HFpEF is infrequently reported in children and instead of using the  HFpEF terminology the HF symptoms are attributed to diastolic dysfunction. Identifying HFpEF in children is challenging because of heterogeneous etiologies and unknown pathophysiological mechanisms. Advances in echocardiography and cardiac magnetic resonance imaging techniques have further increased our understanding of HFpEF in children. However, the literature does not describe the incidence, etiology, clinical features, and treatment of HFpEF in children. At present, treatment of HFpEF in children is extrapolated from clinical trials in adults. There are significant differences between pediatric and adult HF with reduced ejection fraction, supported by a lack of adequate response to adult HF therapies. Evidence-based clinical trials in children are still not available because of the difficulty of conducting trials with a limited number of pediatric patients with HF. The treatment of HFpEF in children is based upon the clinician's experience, and the majority of children receive off-level medications. There are significant differences between pediatric and adult HFpEF pharmacotherapies in many areas, including side-effect profiles, underlying pathophysiologies, the β-receptor physiology, and pharmacokinetics and pharmacodynamics. This review describes the present and future treatments for children with HFpEF compared with adults. This review also highlights the need to urgently test new therapies in children with HFpEF to demonstrate the safety and efficacy of drugs and devices with proven benefits in adults.

Role of Epicardial Adipose Tissue in Cardiovascular Diseases: A Review

Simple Summary

Cardiovascular diseases (CVDs) are the leading causes of death worldwide. Epicardial adipose tissue (EAT) is one of the most important risk factors for cardiovascular events and a promising new therapeutic target in CVDs. Here, we summarize the currently available evidence regarding the role of EAT in the development of CVDs, including coronary artery disease, heart failure and atrial fibrillation; compile data regarding the association between EAT’s function and the course of COVID-19; and present new potential therapeutic possibilities, aiming at modifying EAT’s function. The development of novel therapies specifically targeting EAT could revolutionize the prognosis in CVDs.

Abstract

Cardiovascular diseases (CVDs) are the leading causes of death worldwide. Epicardial adipose tissue (EAT) is defined as a fat depot localized between the myocardial surface and the visceral layer of the pericardium and is a type of visceral fat. EAT is one of the most important risk factors for atherosclerosis and cardiovascular events and a promising new therapeutic target in CVDs. In health conditions, EAT has a protective function, including protection against hypothermia or mechanical stress, providing myocardial energy supply from free fatty acid and release of adiponectin. In patients with obesity, metabolic syndrome, or diabetes mellitus, EAT becomes a deleterious tissue promoting the development of CVDs. Previously, we showed an adverse modulation of gene expression in pericoronary adipose tissue in patients with coronary artery disease (CAD). Here, we summarize the currently available evidence regarding the role of EAT in the development of CVDs, including CAD, heart failure, and atrial fibrillation. Due to the rapid development of the COVID-19 pandemic, we also discuss data regarding the association between EAT and the course of COVID-19. Finally, we present the potential therapeutic possibilities aiming at modifying EAT’s function. The development of novel therapies specifically targeting EAT could revolutionize the prognosis in CVDs.

Efficacy and Safety of Direct Oral Anticoagulants in Stable Coronary Artery Disease and Atrial Fibrillation: A Systematic Review and Network Meta-Analysis

Direct Oral Anticoagulants (DOACs) , which partially replace warfarin, have been developed as a safe and effective therapy for patients with stable coronary artery disease (SCAD) and atrial fibrillation (AF). However, the choice of DOACs and warfarin remains controversial. We conducted a network meta-analysis (NMA) using randomized controlled trials (RCTs) through a systematic literature review to evaluate the the efficacy and safety of DOACs in SCAD and AF patients. Five RCTs with 6524 patients were included. The results showed that patients taking DOACs had a lower risk of stroke/systemic embolism (OR, 0.64; 95% CI, 0.54-0.76, P < .00001, I2 = 89%), intracranial bleeding (OR, 0.41; 95% CI, 0.26-0.64, P = .0001, I2 = 0%), major bleeding (OR, 0.98; 95% CI, 0.81-1.148, P = .80, I2 = 88%), and all-cause mortality (OR, 1.04; 95% CI, 0.88-1.22, P = .66, I2 = 51%) than those taking warfarin. Compared to warfarin, rivaroxaban (20 mg, once/day) was more advantageous in preventing stroke/systemic embolism, as was apixaban (5 mg or 2.5 mg, twice/day) in reducing major bleeding (OR, 0.79; 95% CI, 0.48-1.3) and all-cause mortality (OR, 0.97; 95% CI, 0.69-1.4). Different doses of DOACs showed obvious advantages against intracranial hemorrhage, without significant differences. Thus, DOACs have more effective than warfarin in clinical efficacy and safety.

Heart Failure With Mid-range Ejection Fraction: A Distinctive Subtype or a Transitional Stage?

Heart failure with mid-range ejection fraction (HFmrEF) was first proposed by Lam and Solomon in 2014, and was listed as a new subtype of heart failure (HF) in 2016 European Society of Cardiology guidelines. Since then, HFmrEF has attracted an increasing amount of attention, and the number of related studies on this topic has grown rapidly. The diagnostic criteria on the basis of left ventricular ejection fraction (LVEF) are straightforward; however, LVEF is not a static parameter, and it changes dynamically during the course of HF. Thus, HFmrEF may not be an independent disease with a uniform pathophysiological process, but rather a collection of patients with different characteristics. HFmrEF is often associated with various cardiovascular and non-cardiovascular diseases. Thus, the pathophysiological mechanisms of HFmrEF are particularly complex, and its clinical phenotypes are diverse. The complexity and heterogeneity of HFmrEF may be one reason for inconsistent results between clinical studies. In fact, whether HFmrEF is a distinctive subtype or a transitional stage between HF with reduced ejection fraction (HFrEF) and HF with preserved ejection fraction (HFpEF) is controversial. In this review, we discuss the clinical characteristics, treatment and prognosis of patients with HFmrEF, as well as the differences among HFmrEF, HFrEF, and HFpEF.

Epigenetic Therapies for Heart Failure: Current Insights and Future Potential

Despite the current reductionist approach providing an optimal indication for diagnosis and treatment of patients with heart failure with reduced ejection fraction (HFrEF), there are no standard pharmacological therapies for heart failure with preserved ejection fraction (HFpEF). Although in its infancy in cardiovascular diseases, the epigenetic-based therapy ("epidrugs") is capturing the interest of physician community. In fact, an increasing number of controlled clinical trials is evaluating the putative beneficial effects of: 1) direct epigenetic-oriented drugs, eg, apabetalone, and 2) repurposed drugs with a possible indirect epigenetic interference, eg, metformin, statins, sodium glucose transporter inhibitors 2 (SGLT2i), and omega 3 polyunsaturated fatty acids (PUFAs) in both HFrEF and HFpEF, separately. Apabetalone is the first and unique direct epidrug tested in cardiovascular patients to date, and the BETonMACE trial has reported a reduction in first HF hospitalization (any EF value) and cardiovascular death in patients with type 2 diabetes and recent acute coronary syndrome, suggesting a possible role in secondary prevention. Patients with HFpEF seem to benefit from supplementation to the standard therapy with statins, metformin, and SGLT2i owing to their ability in reducing mortality. In contrast, the vasodilator hydralazine, with or without isosorbide dinitrate, did not provide beneficial effects. In HFrEF, metformin and SGLT2i could reduce the risk of incident HF and mortality in affected patients whereas clinical trials based on statins provided mixed results. Furthermore, PUFAs diet supplementation was significantly associated with reduced cardiovascular risk in both HFpEF and HFrEF. Future large trials will reveal whether direct and indirect epitherapy will remain a work in progress or become a useful way to customize the therapy in the real-world management of HFpEF and HFrEF. Our goal is to discuss the recent advancement in the epitherapy as a possible way to improve personalized therapy of HF.

High density lipoprotein cholesterol / C reactive protein ratio in heart failure with preserved ejection fraction

AIMS

The impacts of high density lipoprotein cholesterol (HDL-C) as an anti-inflammatory and C reactive protein (CRP) as inflammatory properties on the pathogenesis of heart failure were reported. At present, the clinical significance of the HDL-C/CRP ratio in heart failure with preserved ejection fraction (HFpEF) patients remains unknown.

METHODS AND RESULTS

We examined the data on 796 consecutive HFpEF (left ventricular ejection fraction ≥50%) patients hospitalized due to acute decompensated heart failure from the PURSUIT-HFpEF registry, a prospective, multicentre observational study. We calculated the HDL/CRP ratios and evaluated the relationship between the values and clinical outcomes, including degree of cardiac function. The mean follow-up duration was 420 ± 346 days. All-cause death occurred in 118 patients, of which 51 were cardiac deaths. HDL/CRP ≤ 4.05 was independently and significantly associated with all-cause death (odds ratio = 1.84, 95% CI: 1.06-3.20, P = 0.023), and HDL/CRP ≤ 3.14 was associated with cardiac death by multivariate Cox proportional hazard analysis (odds ratio = 2.86, 95% CI: 1.36-6.01, P = 0.003). HDL-C/CRP ratio significantly correlated with the product of the left atrial volume and left ventricular mass index as well as the tricuspid annular plane systolic excursion by multiple regression analysis (standardized beta-coefficient = -0.085, P = 0.034 and standardized beta-coefficient = 0.081, P = 0.044, respectively).

CONCLUSIONS

HDL-C/CRP ratio was a useful marker for predicting all-cause death and cardiac death and correlated with left ventricular diastolic function and right ventricular systolic function in HFpEF patients.

Therapeutic implications of statins in heart failure with reduced ejection fraction and heart failure with preserved ejection fraction: a review of current literature

Statins are one of the standard treatments to prevent cardiovascular events such as coronary artery disease and heart failure (HF). However, data on the use of statins to improve clinical outcomes in patients with established HF remains controversial. We summarized available clinical studies which investigated the effects of statins on clinical outcomes in patients with HF with reduced ejection fraction (HFrEF) and HF with preserved ejection fraction (HFpEF). Statins possess many pleiotropic effects in addition to lipid-lowering properties that positively affect the pathophysiology of HF. In HFrEF, data from two large randomized placebo-controlled trials did not show benefits of statins on mortality of patients with HFrEF. However, more recent prospective cohort studies and meta-analyses have shown decreased risk of mortality as well as cardiovascular hospitalization with statins treatment. In HFpEF, most prospective and retrospective cohort studies as well as meta analyses have consistently reported positive effects of statins, including reducing mortality and improving other clinical outcomes. Current evidence also suggests better outcomes with lipophilic statins in patients with HF. In summary, statins might be effective in improving survival and other clinical outcomes in patients with HF, especially for patients with HFpEF. Lipophilic statins might also be more beneficial for HF patients. Based on current evidence, statins did not cause harm and should be continued in HF patients who are already taking the medication. Further randomized controlled trials are needed to clarify the benefits of statins in HF patients.

Metabolic inflammation in heart failure with preserved ejection fraction

One in 10 persons in the world aged 40 years and older will develop the syndrome of HFpEF (heart failure with preserved ejection fraction), the most common form of chronic cardiovascular disease for which no effective therapies are currently available. Metabolic disturbance and inflammatory burden contribute importantly to HFpEF pathogenesis. The interplay within these two biological processes is complex; indeed, it is now becoming clear that the notion of metabolic inflammation-metainflammation-must be considered central to HFpEF pathophysiology. Inflammation and metabolism interact over the course of syndrome progression, and likely impact HFpEF treatment and prevention. Here, we discuss evidence in support of a causal, mechanistic role of metainflammation in shaping HFpEF, proposing a framework in which metabolic comorbidities profoundly impact cardiac metabolism and inflammatory pathways in the syndrome.

Microvascular and lymphatic dysfunction in HFpEF and its associated comorbidities

Heart failure with preserved ejection fraction (HFpEF) is a complex heterogeneous disease for which our pathophysiological understanding is still limited and specific prevention and treatment strategies are lacking. HFpEF is characterised by diastolic dysfunction and cardiac remodelling (fibrosis, inflammation, and hypertrophy). Recently, microvascular dysfunction and chronic low-grade inflammation have been proposed to participate in HFpEF development. Furthermore, several recent studies demonstrated the occurrence of generalized lymphatic dysfunction in experimental models of risk factors for HFpEF, including obesity, hypercholesterolaemia, type 2 diabetes mellitus (T2DM), hypertension, and aging. Here, we review the evidence for a combined role of coronary (micro)vascular dysfunction and lymphatic vessel alterations in mediating key pathological steps in HFpEF, including reduced cardiac perfusion, chronic low-grade inflammation, and myocardial oedema, and their impact on cardiac metabolic alterations (oxygen and nutrient supply/demand imbalance), fibrosis, and cardiomyocyte stiffness. We focus primarily on HFpEF caused by metabolic risk factors, such as obesity, T2DM, hypertension, and aging.

Management of heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction is a highly heterogenous disease. There is emerging evidence that treatment should be tailored to the individual’s associated comorbidities

No current algorithms exist for the management of heart failure with preserved ejection fraction. Conventional therapies used in heart failure with reduced ejection fraction are yet to show a mortality benefit

Key treatment objectives include control of hypertension and fluid balance

Common comorbidities include coronary artery disease, atrial fibrillation, obesity, diabetes, renal impairment and pulmonary hypertension. These comorbidities should be considered in all patients and treatment optimised

Managing heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) is increasing in prevalence as the general population ages. Poorly managed heart failure symptoms of decompensated HFpEF is one of the most common reasons for prolonged hospital admission. The high rate of morbidity and mortality associated with HFpEF is compounded by a poor understanding of the underpinning pathophysiology. Randomized controlled trials have so far been unable to identify an evidence base for reducing morbidity and mortality in patients with HFpEF, although there is some evidence to support quality of life (QOL) improvement. In this review, we described the recent advances on the pathophysiological understanding of HFpEF, the current and emerging treatment strategies, and what this may mean for individual patients. Potential treatments for HFpEF were divided into their relative management strategies and the current evidence assessed for effect on HFpEF mortality, hospital admission frequency, and QOL improvement. Overall, the understanding of HFpEF pathophysiology is improving and has been made a priority in identifying potential therapeutic targets. There is growing evidence that patients with ejection fractions (EF) of less than 60% may obtain a mortality benefit from ACE-inhibitors, angiotensin-neprilysin inhibitors, Angiotensin Receptor Blockers, and Mineralocorticoid Receptor Antagonists. However, this covers only a small proportion of the HFpEF spectrum. Therefore, currently there are no universal treatment strategies recommended for HFpEF, and management should focus on an individualised approach and this should take into account the comorbidities of each patient.

Impact of Board-Certified Cardiologist Characteristics on Risk of In-Hospital Mortality

Background: This study examined the influence of board-certified cardiologist characteristics on the in-hospital mortality of patients with cardiovascular disease.

Methods and Results: Data were collected between 2012 and 2014 from a nationwide database of acute care hospitals in Japan. Overall, there were 1,422,703 patients, of whom 883,746 were analyzed. The primary outcome was all-cause in-hospital mortality. The association between board-certified cardiologist characteristics and in-hospital mortality was estimated using multilevel mixed-effect logistic regression modeling. Median age of cardiologists in a hospital was not related to in-hospital mortality (OR, 1.003; 95% CI: 0.998–1.008, P=0.316), but a greater cardiologist age range was associated with a lower risk of in-hospital mortality (OR, 0.992; 95% CI: 0.988–0.995 per 1-unit increment in age range, P<0.001). Meanwhile, the average years of experience of the board-certified cardiologists in a hospital was not associated with a lower risk of in-hospital mortality (OR, 1.002; 95% CI: 0.996–1.007, P=0.525), but a greater range of years of experience was (OR, 0.986; 95% CI: 0.983–0.990 per 1-unit increment in range of years of experience, P<0.001).

Conclusions: Median board-certified cardiologist age/experience at an institution is not related to in-hospital mortality, but a greater range in age/experience is associated with a lower risk of mortality.

Heart failure with preserved ejection fraction: present status and future directions

The clinical importance of heart failure with preserved ejection fraction (HFpEF) has recently become apparent. HFpEF refers to heart failure (HF) symptoms with normal or near-normal cardiac function on echocardiography. Common clinical features of HFpEF include diastolic dysfunction, reduced compliance, and ventricular hypokinesia. HFpEF differs from the better-known HF with reduced ejection fraction (HFrEF). Despite having a "preserved ejection fraction," patients with HFpEF have symptoms such as shortness of breath, excessive tiredness, and limited exercise capability. Furthermore, the mortality rate and cumulative survival rate are as severe in HFpEF as they are in HFrEF. While beta-blockers and renin-angiotensin-aldosterone system modulators can improve the survival rate in HFrEF, no known therapeutic agents show similar effectiveness in HFpEF. Researchers have examined molecular events in the development of HFpEF using small and middle-sized animal models. This review discusses HFpEF with regard to etiology and clinical features and introduces the use of mouse and other animal models of human HFpEF.

Microvascular Dysfunction in Heart Failure With Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) is an increasingly studied entity accounting for 50% of all diagnosed heart failure and that has claimed its own dignity being markedly different from heart failure with reduced EF in terms of etiology and natural history (Graziani et al., 2018). Recently, a growing body of evidence points the finger toward microvascular dysfunction as the major determinant of the pathological cascade that justifies clinical manifestations (Crea et al., 2017). The high burden of comorbidities such as metabolic syndrome, hypertension, atrial fibrillation, chronic kidney disease, obstructive sleep apnea, and similar, could lead to a systemic inflammatory state that impacts the physiology of the endothelium and the perivascular environment, engaging complex molecular pathways that ultimately converge to myocardial fibrosis, stiffening, and dysfunction (Paulus and Tschope, 2013). These changes could even self-perpetrate with a positive feedback where hypoxia and locally released inflammatory cytokines trigger interstitial fibrosis and hypertrophy (Ohanyan et al., 2018). Identifying microvascular dysfunction both as the cause and the maintenance mechanism of this condition has opened the field to explore specific pharmacological targets like nitric oxide (NO) pathway, sarcomeric titin, transforming growth factor beta (TGF-β) pathway, immunomodulators or adenosine receptors, trying to tackle the endothelial impairment that lies in the background of this syndrome (Graziani et al., 2018;Lam et al., 2018). Yet, many questions remain, and the new data collected still lack a translation to improved treatment strategies. To further elaborate on this tangled and exponentially growing topic, we will review the evidence favoring a microvasculature-driven etiology of this condition, its clinical correlations, the proposed diagnostic workup, and the available/hypothesized therapeutic options to address microvascular dysfunction in the failing heart.