Present and future pharmacotherapeutic agents in heart failure: an evolving paradigm

Fluorinated perhexiline derivative attenuates vascular proliferation in pulmonary arterial hypertension smooth muscle cells

Increased proliferation and reduced apoptosis of pulmonary artery smooth muscle cells (PASMCs) is recognised as a universal hallmark of pulmonary arterial hypertension (PAH), in part related to the association with reduced pyruvate dehydrogenase (PDH) activity, resulting in decreased oxidative phosphorylation of glucose and increased aerobic glycolysis (Warburg effect). Perhexiline is a well-recognised carnitine palmitoyltransferase-1 (CPT1) inhibitor used in cardiac diseases, which reciprocally increases PDH activity, but is associated with variable pharmacokinetics related to polymorphic variation of the cytochrome P450-2D6 (CYP2D6) enzyme, resulting in the risk of neuro and hepatotoxicity in 'slow metabolisers' unless blood levels are monitored and dose adjusted. We have previously reported that a novel perhexiline fluorinated derivative (FPER-1) has the same therapeutic profile as perhexiline but is not metabolised by CYP2D6, resulting in more predictable pharmacokinetics than the parent drug. We sought to investigate the effects of perhexiline and FPER-1 on PDH flux in PASMCs from patients with PAH. We first confirmed that PAH PASMCs exhibited increased cell proliferation, enhanced phosphorylation of AKTSer473, ERK 1/2Thr202/Tyr204 and PDH-E1αSer293, indicating a Warburg effect when compared to healthy PASMCs. Pre-treatment with perhexiline or FPER-1 significantly attenuated PAH PASMC proliferation in a concentration-dependent manner and suppressed the activation of the AKTSer473 but had no effect on the ERK pathway. Perhexiline and FPER-1 markedly activated PDH (seen as dephosphorylation of PDH-E1αSer293), reduced glycolysis, and upregulated mitochondrial respiration in these PAH PASMCs as detected by Seahorse analysis. However, both perhexiline and FPER-1 did not induce apoptosis as measured by caspase 3/7 activity. We show for the first time that both perhexiline and FPER-1 may represent therapeutic agents for reducing cell proliferation in human PAH PASMCs, by reversing Warburg physiology.

Effect of Sotagliflozin on Early Mortality and Heart Failure-Related Events: A Post Hoc Analysis of SOLOIST-WHF

BACKGROUND

Approximately 25% of patients admitted to hospitals for worsening heart failure (WHF) are readmitted within 30 days.

OBJECTIVES

The authors conducted a post hoc analysis of the SOLOIST-WHF (Effect of Sotagliflozin on Cardiovascular Events in Patients With Type 2 Diabetes Post-WHF) trial to evaluate the efficacy of sotagliflozin versus placebo to decrease mortality and HF-related events among patients who began study treatment on or before discharge from their index hospitalization.

METHODS

The main endpoint of interest was cardiovascular death or HF-related event (HF hospitalization or urgent care visit) occurring within 90 and 30 days after discharge for the index WHF hospitalization. Treatment comparisons were by proportional hazards models, generating HRs, 95% CIs, and P values.

RESULTS

Of 1,222 randomized patients, 596 received study drug on or before their date of discharge. Sotagliflozin reduced the main endpoint at 90 days after discharge (HR: 0.54 [95% CI: 0.35-0.82]; P = 0.004) and at 30 days (HR: 0.49 [95% CI: 0.27-0.91]; P = 0.023) and all-cause mortality at 90 days (HR: 0.39 [95% CI: 0.17-0.88]; P = 0.024). In subgroup analyses, sotagliflozin reduced the 90-day main endpoint regardless of sex, age, estimated glomerular filtration rate, N-terminal pro-B-type natriuretic peptide, left ventricular ejection fraction, or mineralocorticoid receptor agonist use. Sotagliflozin was well-tolerated but with slightly higher rates of diarrhea and volume-related events than placebo.

CONCLUSIONS

Starting sotagliflozin before discharge in patients with type 2 diabetes hospitalized for WHF significantly decreased cardiovascular deaths and HF events through 30 and 90 days after discharge, emphasizing the importance of beginning sodium glucose cotransporter treatment before discharge.

Tolerance of Rodents to an Intravenous Bolus Injection of Sodium Nitrate in a High Concentration

Simple Summary

Nitrate is found in many foods and is a common metabolite that is supplied mostly through the diet. Recently, we have found that an analog of this compound, labeled with the stable isotope (non-radioactive) nitrogen-15, is a potentially useful contrast agent for magnetic resonance imaging (MRI), as it does not include a metal component as most other MRI contrast agents. This analog was previously shown with a very high magnetic resonance signal, which is relatively long-lasting, when combined with the new adjunct technology to MRI called hyperpolarization. Prior to serving as a contrast agent for MRI in patients, this agent needs to be tested and validated in small animals. As a prerequisite to such studies, one must ensure that the injection of the naturally abundant agent (not labeled with any isotopes) will be tolerated by the animals. The purpose of the current study was to evaluate the tolerance to an intravenous injection of sodium nitrate in rats and mice, as MRI contrast agents are routinely administered in this way. We have found that a high dose of sodium nitrate can be safely injected into rats and mice. This result opens the way for preclinical MRI studies with sodium nitrate.

Abstract

Nitrate, the inorganic anion NO₃⁻, is found in many foods and is an endogenous mammalian metabolite, which is supplied mostly through the diet. Although much is known about the safety of sodium nitrate when given per os, methodological safety data on intravenous bolus injection of sodium nitrate to rodents are lacking. Recently, we have proposed a new use for nitrate, as a contrast agent for magnetic resonance imaging that will be metal free and leave no traces in the body and the environment further to the imaging examination. It was shown that a stable isotope-labelled analog of this ion (¹⁵NO₃⁻), in a sodium nitrate solution form and hyperpolarized state, produces a high magnetic resonance signal with prolonged visibility. Therefore, sodium nitrate was targeted for further preclinical development in this context. In the absence of methodological safety data on the potential effects of a high concentration sodium nitrate bolus intravenous injection into rodents, we carried out such an investigation in mice and rats (n = 12 of each, 6 males and 6 females in each group, altogether 24 animals). We show here that an intravenous bolus administration of sodium nitrate at a concentration of 150 mM and a dose of 51 mg/Kg does not lead to adverse effects in mice and rats. This is the first investigation of the tolerance of rodents to an intravenous injection of sodium nitrate.

DCRM Multispecialty Practice Recommendations for the management of diabetes, cardiorenal, and metabolic diseases

Type 2 diabetes (T2D), chronic kidney disease (CKD), atherosclerotic cardiovascular disease (ASCVD), and heart failure (HF)-along with their associated risk factors-have overlapping etiologies, and two or more of these conditions frequently occur in the same patient. Many recent cardiovascular outcome trials (CVOTs) have demonstrated the benefits of agents originally developed to control T2D, ASCVD, or CKD risk factors, and these agents have transcended their primary indications to confer benefits across a range of conditions. This evolution in CVOT evidence calls for practice recommendations that are not constrained by a single discipline to help clinicians manage patients with complex conditions involving diabetes, cardiorenal, and/or metabolic (DCRM) diseases. The ultimate goal for these recommendations is to be comprehensive yet succinct and easy to follow by the nonexpert-whether a specialist or a primary care clinician. To meet this need, we formed a volunteer task force comprising leading cardiologists, nephrologists, endocrinologists, and primary care physicians to develop the DCRM Practice Recommendations, a multispecialty consensus on the comprehensive management of the patient with complicated metabolic disease. The task force recommendations are based on strong evidence and incorporate practical guidance that is clinically relevant and simple to implement, with the aim of improving outcomes in patients with DCRM. The recommendations are presented as 18 separate graphics covering lifestyle therapy, patient self-management education, technology for DCRM management, prediabetes, cognitive dysfunction, vaccinations, clinical tests, lipids, hypertension, anticoagulation and antiplatelet therapy, antihyperglycemic therapy, hypoglycemia, nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH), ASCVD, HF, CKD, and comorbid HF and CKD, as well as a graphical summary of medications used for DCRM.

Role of ranolazine in heart failure: From cellular to clinic perspective

Ranolazine was approved by the US Food and Drug Administration as an antianginal drug in 2006, and has been used since in certain groups of patients with stable angina. The therapeutic action of ranolazine was initially attributed to inhibitory effects on fatty acids metabolism. As investigations went on, however, it developed that the main beneficial effects of ranolazine arise from its action on the late sodium current in the heart. Since late sodium currents were discovered to be involved in various heart pathologies such as ischemia, arrhythmias, systolic and diastolic dysfunctions, and all these conditions are associated with heart failure, ranolazine has in some way been tested either directly or indirectly on heart failure in numerous experimental and clinical studies. As the heart continuously remodels following any sort of severe injury, the inhibition by ranolazine of the underlying mechanisms of cardiac remodeling including ion disturbances, oxidative stress, inflammation, apoptosis, fibrosis, metabolic dysregulation, and neurohormonal impairment are discussed, along with unresolved issues. A projection of pathologies targeted by ranolazine from cellular level to clinical is provided in this review.

Mitochondrial dysfunction and mitochondrial therapies in heart failure

Cardiovascular diseases remain the leading cause of death worldwide in the last decade, accompanied by immense health and economic burdens. Heart failure (HF), as the terminal stage of many cardiovascular diseases, is a common, intractable, and costly medical condition. Despite significant improvements in pharmacologic and device therapies over the years, life expectancy for this disease remains poor. Current therapies have not reversed the trends in morbidity and mortality as expected. Thus, there is an urgent need for novel potential therapeutic agents. Although the pathophysiology of the failing heart is extraordinarily complex, targeting mitochondrial dysfunction can be an effective approach for potential treatment. Increasing evidence has shown that mitochondrial abnormalities, including altered metabolic substrate utilization, impaired mitochondrial oxidative phosphorylation (OXPHOS), increased reactive oxygen species (ROS) formation, and aberrant mitochondrial dynamics, are closely related to HF. Here, we reviewed the findings on the role of mitochondrial dysfunction in HF, along with novel mitochondrial therapeutics and their pharmacological effects.

Hyperpolarized [15N]nitrate as a potential long lived hyperpolarized contrast agent for MRI

Reports on gadolinium deposits in the body and brains of adults and children who underwent contrast-enhanced MRI examinations warrant development of new, metal free, contrast agents for MRI. Nitrate is an abundant ion in mammalian biochemistry and sodium nitrate can be safely injected intravenously. We show that hyperpolarized [¹⁵N]nitrate can potentially be used as an MR tracer. The ¹⁵N site of hyperpolarized [¹⁵N]nitrate showed a T₁ of more than 100 s in aqueous solutions, which was prolonged to more than 170 s below 20 °C. Capitalizing on this effect for polarization storage we obtained a visibility window of 9 min in blood. Conversion to [¹⁵N]nitrite, the bioactive reduced form of nitrate, was not observed in human blood and human saliva in this time frame. Thus, [¹⁵N]nitrate may serve as a long-lived hyperpolarized tracer for MR. Due to its ionic nature, the immediate applications appear to be perfusion and tissue retention imaging.

Cardiac metabolism - A promising therapeutic target for heart failure

Both heart failure with reduced ejection fraction (HFrEF) and with preserved ejection fraction (HFpEF) are associated with high morbidity and mortality. Although many established pharmacological interventions exist for HFrEF, hospitalization and death rates remain high, and for those with HFpEF (approximately half of all heart failure patients), there are no effective therapies. Recently, the role of impaired cardiac energetic status in heart failure has gained increasing recognition with the identification of reduced capacity for both fatty acid and carbohydrate oxidation, impaired function of the electron transport chain, reduced capacity to transfer ATP to the cytosol, and inefficient utilization of the energy produced. These nodes in the genesis of cardiac energetic impairment provide potential therapeutic targets, and there is promising data from recent experimental and early-phase clinical studies evaluating modulators such as carnitine palmitoyltransferase 1 inhibitors, partial fatty acid oxidation inhibitors and mitochondrial-targeted antioxidants. Metabolic modulation may provide significant symptomatic and prognostic benefit for patients suffering from heart failure above and beyond guideline-directed therapy, but further clinical trials are needed.

Targeting Metabolic Modulation and Mitochondrial Dysfunction in the Treatment of Heart Failure

Despite significant improvements in morbidity and mortality with current evidence-based pharmaceutical-based treatment of heart failure (HF) over the previous decades, the burden of HF remains high. An alternative approach is currently being developed, which targets myocardial energy efficiency and the dysfunction of the cardiac mitochondria. Emerging evidence suggests that the insufficient availability of ATP to the failing myocardium can be attributed to abnormalities in the myocardial utilisation of its substrates rather than an overall lack of substrate availability. Therefore, the development of potential metabolic therapeutics has commenced including trimetazidine, ranolazine and perhexiline, as well as specific mitochondrial-targeting pharmaceuticals, such as elamipretide. Large randomised controlled trials are required to confirm the role of metabolic-modulating drugs in the treatment of heart failure, but early studies have been promising in their possible efficacy for the management of heart failure in the future.

Development of Fluorinated Analogues of Perhexiline with Improved Pharmacokinetic Properties and Retained Efficacy

We designed and synthesized perhexiline analogues that have the same therapeutic profile as the parent cardiovascular drug but lacking its metabolic liability associated with CYP2D6 metabolism. Cycloalkyl perhexiline analogues 6a-j were found to be unsuitable for further development, as they retained a pharmacokinetic profile very similar to that shown by the parent compound. Multistep synthesis of perhexiline analogues incorporating fluorine atoms onto the cyclohexyl ring(s) provided a range of different fluoroperhexiline analogues. Of these, analogues 50 (4,4-gem-difluoro) and 62 (4,4,4',4'-tetrafluoro) were highly stable and showed greatly reduced susceptibility to CYP2D6-mediated metabolism. In vitro efficacy studies demonstrated that a number of derivatives retained acceptable potency against CPT-1. Having the best balance of properties, 50 was selected for further evaluation. Like perhexiline, it was shown to be selectively concentrated in the myocardium and, using the Langendorff model, to be effective in improving both cardiac contractility and relaxation when challenged with high fat buffer.

Prescription pattern of Chinese herbal products for heart failure in Taiwan: A population-based study

BACKGROUND

Certain Chinese herbal products (CHPs) may protect against the progression of heart failure (HF). However, there is a lack of research regarding the use of CHPs in patients with HF. The aims of this study were to analyze CHPs usage patterns in patients with HF and to identify the frequency and combination of CHPs most commonly used for HF.

METHODS

This retrospective, nationwide, population-based cohort study was conducted using a randomly sampled cohort of one million patients selected from the National Health Insurance Research Database (NHIRD) for the years 2000-2010 in Taiwan. CHP use and the top ten most frequently prescribed formulae and single herbs for treating HF were assessed, including total formulae number and average and frequency of prescriptions. Demographic characteristics, including sex and age at diagnosis of HF, were examined, together with existing comorbidities.

RESULTS

The cohort included 19,988 newly diagnosed AD patients, who were given CHP treatment for HF between 2000 and 2010. Among them, female patients (53.3%) and those over 65years old (63.9%) were more likely to use CM. After adjusting for demographic factors, HF patients suffering from coronary artery disease (CAD) were more likely to seek traditional Chinese medicine (TCM) treatment than those with non-TCM users (57.6% vs. 52.6%). Zhi-Gan-Cao-Tang (4.07%) and Danshen (5.13%) were the most frequent formula CHP and single CHP prescribed by TCM practitioners for treating HF, respectively.

CONCLUSION

Most people with HF who consumed CHPs used CHPs to supplement Yang-Qi, nourish the Ying-blood, and strengthen the heart spirit as complementary medicines to relieve HF-related symptoms, in addition to using standard anti-HF treatments. Further large-scale, randomized clinical trials are warranted in order to determine the effectiveness and safety of these herbal medicines.

Present and future pharmacotherapeutic agents in heart failure: an evolving paradigm

Many conditions culminate in heart failure (HF), a multi‐organ systemic syndrome with an intrinsically poor prognosis. Pharmacotherapeutic agents that correct neurohormonal dysregulation and haemodynamic instability have occupied the forefront of developments within the treatment of HF in the past. Indeed, multiple trials aimed to validate these agents in the 1980s and early 1990s, resulting in a large and robust evidence‐base supporting their use clinically. An established treatment paradigm now exists for the treatment of HF with reduced ejection fraction (HFrEF), but there have been very few notable developments in recent years. HF remains a significant health concern with an increasing incidence as the population ages. We may indeed be entering the surgical era for HF treatment, but these therapies remain expensive and inaccessible to many. Newer pharmacotherapeutic agents are slowly emerging, many targeting alternative therapeutic pathways, but with mixed results. Metabolic modulation and manipulation of the nitrate/nitrite/nitric oxide pathway have shown promise and could provide the answers to fill the therapeutic gap between medical interventions and surgery, but further definitive trials are warranted. We review the significant evidence base behind the current medical treatments for HFrEF, the physiology of metabolic impairment in HF, and discuss two promising novel agents, perhexiline and nitrite.