Are the effects of drugs to prevent and to treat heart failure always concordant? The statin paradox and its implications for understanding the actions of antidiabetic medications

Uncovering the Role of Epicardial Adipose Tissue in Heart Failure With Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) is the most common form of heart failure. Obesity is a modifiable risk factor of HFpEF; however, body mass index provides limited information on visceral adiposity and patients with similar anthropometrics can present variable cardiovascular risk. Epicardial adipose tissue (EAT) is the closest fat deposit to the heart and has been proposed as a biomarker of visceral adiposity. EAT may be particularly important for cardiac function, because of its location (under the pericardium) and because it acts as a metabolically active endocrine organ (which can produce both beneficial and detrimental cytokines). In this paper, the authors review the role of EAT in normal and pathologic conditions and discuss the noninvasive imaging modalities that allow its identification. This review highlights EAT implications in HFpEF and discuss new therapies that act on EAT and might also exert beneficial effects on the cardiovascular system.

Choosing statins: a review to guide clinical practice

Statins are among the most widely prescribed medicines in the world and have proved their value in reducing cardiovascular events and mortality. Many patients report adverse effects that lead to interruption of treatment. This review aims to individualize statin treatment, considering efficacy for reducing cardiovascular risk and safety, in the setting of specific diseases, to minimize the side effects and improve compliance. We gathered evidence that may help clinicians to choose specific statins in different clinical situations, such as the risk of new diabetes, chronic kidney disease, liver disease, human immunodeficiency virus infection, organ transplant, heart failure and elderly people. Efficacy of statins is well established in a large number of clinical conditions. Therefore, main objective is to revise statin in specific clinical settings, based on pharmacokinetics, safety, drug metabolism and interactions to provide the best choice in different clinical scenarios.

Determinants of the survival benefit associated with statins in patients with acute heart failure

Aims

The benefit of statins in patients with heart failure (HF) remains controversial and the mechanism of action is largely speculative. We investigated the determinants of the survival benefit associated with statins in HF patients.

Methods and results

We enrolled 1680 acute HF patients receiving statins and 2157 patients not receiving statins admitted between 2009 and 2016. The left ventricular (LV) global longitudinal strain (GLS) was assessed as a measure of myocardial contractility. The primary outcome was 5 year all‐cause mortality. Statin therapy was independently associated with improved survival in patients with HF with preserved ejection fraction (HFpEF) [adjusted hazard ratio (HR) 0.781, 95% confidence interval (CI) 0.621–0.981, P = 0.034], but not in those with HF with reduced EF (HFrEF) (adjusted HR 0.881, 95% CI 0.712–1.090, P = 0.244). Mortality reduction associated with statin therapy was significant in patients with ischaemic HF (adjusted HR 0.775, 95% CI 0.607–0.989, P = 0.040), but not in those with non‐ischaemic HF (adjusted HR 0.895, 95% CI 0.734–1.092, P = 0.275). The relative magnitude of survival benefit with statin therapy increased as LV‐EF and LV‐GLS increased, with a steeper dose–response relationship in patients with ischaemic HF. In the subgroup of patients with ischaemic HF, survival benefit with statin therapy was confined to those ≤75 years of age.

Conclusions

Our study suggests that the survival benefit of statins is confined to patients with HFpEF and those with ischaemic HF. Myocardial contractility may modulate the prognostic effects of statins in HF patients, particularly when the aetiology is ischaemic rather than non‐ischaemic.

Endothelial Klf2-Foxp1-TGFβ signal mediates the inhibitory effects of simvastatin on maladaptive cardiac remodeling

Aims: Pathological cardiac fibrosis and hypertrophy are common features of left ventricular remodeling that often progress to heart failure (HF). Endothelial cells (ECs) are the most abundant non-myocyte cells in adult mouse heart. Simvastatin, a strong inducer of Krüppel-like Factor 2 (Klf2) in ECs, ameliorates pressure overload induced maladaptive cardiac remodeling and dysfunction. This study aims to explore the detailed molecular mechanisms of the anti-remodeling effects of simvastatin.

Methods and Results: RGD-magnetic-nanoparticles were used to endothelial specific delivery of siRNA and we found absence of simvastatin's protective effect on pressure overload induced maladaptive cardiac remodeling and dysfunction after in vivo inhibition of EC-Klf2. Mechanism studies showed that EC-Klf2 inhibition reversed the simvastatin-mediated reduction of fibroblast proliferation and myofibroblast formation, as well as cardiomyocyte size and cardiac hypertrophic genes, which suggested that EC-Klf2 might mediate the anti-fibrotic and anti-hypertrophy effects of simvastatin. Similar effects were observed after Klf2 inhibition in cultured ECs. Moreover, Klf2 regulated its direct target gene TGFβ1 in ECs and mediated the protective effects of simvastatin, and inhibition of EC-Klf2 increased the expression of EC-TGFβ1 leading to simvastatin losing its protective effects. Also, EC-Klf2 was found to regulate EC-Foxp1 and loss of EC-Foxp1 attenuated the protective effects of simvastatin similar to EC-Klf2 inhibition.

Conclusions: We conclude that cardiac microvasculature ECs are important in the modulation of pressure overload induced maladaptive cardiac remodeling and dysfunction, and the endothelial Klf2-TGFβ1 or Klf2-Foxp1-TGFβ1 pathway mediates the preventive effects of simvastatin. This study demonstrates a novel mechanism of the non-cholesterol lowering effects of simvastatin for HF prevention.

Atrial Fibrillation and Heart Failure With Preserved Ejection Fraction in Patients With Nonalcoholic Fatty Liver Disease

The most common causes of chronic liver disease in the developed world-nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH)-are the hepatic manifestations of an insulin-resistant state that is linked to visceral adiposity and systemic inflammation. NAFLD and NASH lead to an expansion of epicardial adipose tissue and the release of proinflammatory adipocytokines that cause microcirculatory dysfunction and fibrosis of the adjoining myocardium, resulting in atrial fibrillation as well as heart failure with a preserved ejection fraction (HFpEF). Inflammatory changes in the left atrium lead to electroanatomical remodeling; thus, NAFLD and NASH markedly increase the risk of atrial fibrillation. Simultaneously, patients with NAFLD or NASH commonly show diastolic dysfunction or latent HFpEF. Interventions include 1) weight loss by caloric restriction, bariatric surgery, or intensive exercise, and 2) drugs that ameliorate fat-mediated inflammation in both the liver and heart (eg, statins, metformin, sodium-glucose cotransporter 2 inhibitors, glucagon-like peptide-1 receptor agonists, and pioglitazone). Patients with NAFLD or NASH commonly have an inflammation-related atrial and ventricular myopathy, which may contribute to symptoms and long-term outcomes.

Physiological monitoring of the complex multimorbid heart failure patient - diabetes and monitoring glucose control

Heart failure (HF) is a global epidemic, particularly affecting the elderly and/or frail patients often with comorbidities. Amongst the comorbidities, type 2 diabetes mellitus (T2DM) is highly prevalent and associated with higher morbidity and mortality. We review the detection and treatment of T2DM in HF and the need to balance the risk of hypoglycaemia and overall glycaemic control. Despite large attributable risks, T2DM is often underdiagnosed in HF. Therefore there is a need for systematic monitoring (screening) for undetected T2DM in HF patients. Given that patients with HF are at greater risk for developing T2DM compared with the general population, an emphasis also has to be placed on regular reassessment of glycaemic status during follow-up. Therefore, glucose-lowering therapies (e.g. sodium-glucose cotransporter-2 inhibitors, SGLT-2 inhibitors) with a known benefit for the prevention or delay of HF hospitalization could be considered early in the course of T2DM, to optimise treatment and reduce cardiovascular (CV) risk. Although intensive glycaemic control has been shown to effectively reduce the risk of microvascular complications in T2DM, these same trials have shown either no reduction in CV outcomes, or even an increase in mortality with tight glycaemic control (i.e. targeting HbA1c levels <7.0%). More lenient glycaemic targets (e.g. HbA1c levels 7.0-8.0%) may be more appropriate for HF patients with T2DM. The 2016 ESC Guidelines for the diagnosis and treatment of HF proposed metformin as the first-line therapy, given its long-standing use and low risk of hypoglycaemia. More recently, several novel glucose lowering-medications have been introduced, including dipeptidyl peptidase-4 (DPP-4) inhibitors, glucagon-like peptide-1 receptor agonists (GLP-1 RA), and SGLT-2 inhibitors. The most consistent reduction in the risk of HF hospitalisation has been shown with the three SGLT-2 inhibitors (empagliflozin, canagliflozin and dapagliflozin) which now offer improved outcomes in patients with both HF and T2DM.

Do most patients with obesity or type 2 diabetes, and atrial fibrillation, also have undiagnosed heart failure? A critical conceptual framework for understanding mechanisms and improving diagnosis and treatment

Obesity and diabetes can lead to heart failure with preserved ejection fraction (HFpEF), potentially because they both cause expansion and inflammation of epicardial adipose tissue and thus lead to microvascular dysfunction and fibrosis of the underlying left ventricle. The same process also causes an atrial myopathy, which is clinically evident as atrial fibrillation (AF); thus, AF may be the first manifestation of HFpEF. Many patients with apparently isolated AF have latent HFpEF or subsequently develop HFpEF. Most patients with obesity or diabetes who have AF and exercise intolerance have increased left atrial pressures at rest or during exercise, even in the absence of diagnosed HFpEF. Among patients with AF, those who also have latent HFpEF have increased risk for systemic thromboembolism and death. The identification of HFpEF in patients with obesity or diabetes alters the risk-to-benefit relationship of commonly prescribed treatments. Bariatric surgery and statins can ameliorate AF and reduce the risk for HFpEF. Conversely, antihyperglycaemic drugs that promote adipogenesis or cause sodium retention (insulin and thiazolidinediones) may increase the risk for heart failure in patients with an underlying ventricular myopathy. Patients with obesity and diabetes who undergo catheter ablation for AF are at increased risk for AF recurrence and for post-ablation increases in pulmonary venous pressures and worsening heart failure, especially if HFpEF coexists. Therefore, AF may be the earliest indicator of HFpEF in patients with obesity or type 2 diabetes, and recognition of HFpEF alters the management of these patients.

Heart Failure End Points in Cardiovascular Outcome Trials of Sodium Glucose Cotransporter 2 Inhibitors in Patients With Type 2 Diabetes Mellitus: A Critical Evaluation of Clinical and Regulatory Issues

Following regulatory guidance set forth in 2008 by the US Food and Drug Administration for new drugs for type 2 diabetes mellitus, many large randomized, controlled trials have been conducted with the primary goal of assessing the safety of antihyperglycemic medications on the primary end point of major adverse cardiovascular events, defined as cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke. Heart failure (HF) was not specifically mentioned in the US Food and Drug Administration guidance and therefore it was not a focus of these studies when planned. Several trials subsequently showed the impact of antihyperglycemic drugs on HF outcomes, which were not originally specified as the primary end point of the trials. The most impressive finding has been the substantial and consistent risk reduction in HF hospitalization seen across 4 trials of sodium glucose cotransporter 2 inhibitors. However, to date, these results have not led to regulatory approval of any of these drugs for a HF indication or a recommendation for use by US HF guidelines. It is therefore important to explore to what extent persuasive treatment effects on nonprimary end points can be used to support regulatory claims and guideline recommendations. This topic was discussed by researchers, clinicians, industry sponsors, regulators, and representatives from professional societies, who convened on the US Food and Drug Administration campus on March 6, 2019. This report summarizes these discussions and the key takeaway messages from this meeting.

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.

Evaluation of the effects of sodium-glucose co-transporter 2 inhibition with empagliflozin on morbidity and mortality in patients with chronic heart failure and a preserved ejection fraction: rationale for and design of the EMPEROR-Preserved Trial

BACKGROUND

The principal biological processes that characterize heart failure with a preserved ejection fraction (HFpEF) are systemic inflammation, epicardial adipose tissue accumulation, coronary microcirculatory rarefaction, myocardial fibrosis and vascular stiffness; the resulting impairment of left ventricular and aortic distensibility (especially when accompanied by impaired glomerular function and sodium retention) causes increases in cardiac filling pressures and exertional dyspnoea despite the relative preservation of left ventricular ejection fraction. Independently of their actions on blood glucose, sodium-glucose co-transporter 2 (SGLT2) inhibitors exert a broad range of biological effects (including actions to inhibit cardiac inflammation and fibrosis, antagonize sodium retention and improve glomerular function) that can ameliorate the pathophysiological derangements in HFpEF. Such SGLT2 inhibitors exert favourable effects in experimental models of HFpEF and have been found in large-scale trials to reduce the risk for serious heart failure events in patients with type 2 diabetes, many of whom were retrospectively identified as having HFpEF.

STUDY DESIGN

The EMPEROR-Preserved Trial is enrolling ≈5750 patients with HFpEF (ejection fraction >40%), with and without type 2 diabetes, who are randomized to receive placebo or empagliflozin 10 mg/day, which is added to all appropriate treatments for HFpEF and co-morbidities.

STUDY AIMS

The primary endpoint is the time-to-first-event analysis of the combined risk for cardiovascular death or hospitalization for heart failure. The trial will also evaluate the effects of empagliflozin on renal function, cardiovascular death, all-cause mortality and recurrent hospitalization events, and will assess a wide range of biomarkers that reflect important pathophysiological mechanisms that may drive the evolution of HFpEF. The EMPEROR-Preserved Trial is well positioned to determine if empagliflozin can have a meaningful impact on the course of HFpEF, a disorder for which there are currently few therapeutic options.

Cholesterol-Lowering Gene Therapy Prevents Heart Failure with Preserved Ejection Fraction in Obese Type 2 Diabetic Mice

Hypercholesterolemia may be causally related to heart failure with preserved ejection fraction (HFpEF). We aimed to establish a HFpEF model associated with hypercholesterolemia and type 2 diabetes mellitus by feeding a high-sucrose/high-fat (HSHF) diet to C57BL/6J low-density lipoprotein receptor (LDLr)^−/− mice. Secondly, we evaluated whether cholesterol-lowering adeno-associated viral serotype 8 (AAV8)-mediated LDLr gene transfer prevents HFpEF. AAV8-LDLr gene transfer strongly (p < 0.001) decreased plasma cholesterol in standard chow (SC) mice (66.8 ± 2.5 mg/dl versus 213 ± 12 mg/dl) and in HSHF mice (84.6 ± 4.4 mg/dl versus 464 ± 25 mg/dl). The HSHF diet induced cardiac hypertrophy and pathological remodeling, which were potently counteracted by AAV8-LDLr gene transfer. Wet lung weight was 19.0% (p < 0.001) higher in AAV8-null HSHF mice than in AAV8-null SC mice, whereas lung weight was normal in AAV8-LDLr HSHF mice. Pressure–volume loop analysis was consistent with HFpEF in AAV8-null HSHF mice and showed a completely normal cardiac function in AAV8-LDLr HSHF mice. Treadmill exercise testing demonstrated reduced exercise capacity in AAV8-null HSHF mice but a normal capacity in AAV8-LDLr HSHF mice. Reduced oxidative stress and decreased levels of tumor necrosis factor-α may mediate the beneficial effects of cholesterol lowering. In conclusion, AAV8-LDLr gene therapy prevents HFpEF.