Effects of low-dose oral enoximone administration on mortality, morbidity, and exercise capacity in patients with advanced heart failure: the randomized, double-blind, placebo-controlled, parallel group ESSENTIAL trials

Phosphodiesterase in heart and vessels: from physiology to diseases

Phosphodiesterases (PDEs) are a superfamily of enzymes that hydrolyze cyclic nucleotides, including cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP). Both cyclic nucleotides are critical secondary messengers in the neurohormonal regulation in the cardiovascular system. PDEs precisely control spatiotemporal subcellular distribution of cyclic nucleotides in a cell- and tissue-specific manner, playing critical roles in physiological responses to hormone stimulation in the heart and vessels. Dysregulation of PDEs has been linked to the development of several cardiovascular diseases, such as hypertension, aneurysm, atherosclerosis, arrhythmia, and heart failure. Targeting these enzymes has been proven effective in treating cardiovascular diseases and is an attractive and promising strategy for the development of new drugs. In this review, we discuss the current understanding of the complex regulation of PDE isoforms in cardiovascular function, highlighting the divergent and even opposing roles of PDE isoforms in different pathogenesis.

Trends and predictors of intracranial hemorrhage in patients with advanced heart failure on left ventricular assist device from 2005 to 2014 in the United States

OBJECTIVES

Left ventricular assist devices are known to extend survival in patients with advanced heart failure; however, their association with intracranial hemorrhage is also well-known. We aimed to explore the risk trend and predictors of intracranial hemorrhage in patients with left ventricular assist devices.

MATERIAL AND METHODS

We included patients aged 18 years or older with left ventricular assist devices hospitalized in the US from 2005 to 2014 using the National Inpatient Sample. We computed the survey-weighted percentages with intracranial hemorrhage across the 10-year study period and assessed whether the proportions changed over time. Predictors of intracranial hemorrhage were evaluated using multivariable logistic regression model.

RESULTS

Of 33,246 hospitalizations, 568 (1.7%) had intracranial hemorrhage. The number of left ventricular assist devices placements increased from 873 in 2005 to 5175 in 2014. However, the risk of intracranial hemorrhage remained largely unchanged (1.7% to 2.3%; linear trend, P = 0.604). The adjusted odds of intracranial hemorrhage were increased with the presence of one of the following variables: female sex (odds ratio [OR], 1.58; 95% CI, 1.03-2.43), history of ischemic stroke (OR, 3.13; 95% CI, 1.86-5.28), or Charlson Comorbidity Index score of 3 or more (OR, 77.40; 95% CI, 10.03-597.60).

CONCLUSIONS

Over the last decade, the risk of intracranial hemorrhage has remained relatively unchanged despite an increase in the use of left ventricular assist devices in patients with advanced heart failure. Women, higher Charlson Comorbidity Index scores, and history of ischemic stroke were associated with higher odds of intracranial hemorrhage in patients with left ventricular assist devices.

Engineered cardiac tissue model of restrictive cardiomyopathy for drug discovery

Restrictive cardiomyopathy (RCM) is defined as increased myocardial stiffness and impaired diastolic relaxation leading to elevated ventricular filling pressures. Human variants in filamin C (FLNC) are linked to a variety of cardiomyopathies, and in this study, we investigate an in-frame deletion (c.7416_7418delGAA, p.Glu2472_Asn2473delinAsp) in a patient with RCM. Induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) with this variant display impaired relaxation and reduced calcium kinetics in 2D culture when compared with a CRISPR-Cas9-corrected isogenic control line. Similarly, mutant engineered cardiac tissues (ECTs) demonstrate increased passive tension and impaired relaxation velocity compared with isogenic controls. High-throughput small-molecule screening identifies phosphodiesterase 3 (PDE3) inhibition by trequinsin as a potential therapy to improve cardiomyocyte relaxation in this genotype. Together, these data demonstrate an engineered cardiac tissue model of RCM and establish the translational potential of this precision medicine approach to identify therapeutics targeting myocardial relaxation.

Cyclic nucleotide phosphodiesterases as therapeutic targets in cardiac hypertrophy and heart failure

Cyclic nucleotide phosphodiesterases (PDEs) modulate the neurohormonal regulation of cardiac function by degrading cAMP and cGMP. In cardiomyocytes, multiple PDE isozymes with different enzymatic properties and subcellular localization regulate local pools of cyclic nucleotides and specific functions. This organization is heavily perturbed during cardiac hypertrophy and heart failure (HF), which can contribute to disease progression. Clinically, PDE inhibition has been considered a promising approach to compensate for the catecholamine desensitization that accompanies HF. Although PDE3 inhibitors, such as milrinone or enoximone, have been used clinically to improve systolic function and alleviate the symptoms of acute HF, their chronic use has proved to be detrimental. Other PDEs, such as PDE1, PDE2, PDE4, PDE5, PDE9 and PDE10, have emerged as new potential targets to treat HF, each having a unique role in local cyclic nucleotide signalling pathways. In this Review, we describe cAMP and cGMP signalling in cardiomyocytes and present the various PDE families expressed in the heart as well as their modifications in pathological cardiac hypertrophy and HF. We also appraise the evidence from preclinical models as well as clinical data pointing to the use of inhibitors or activators of specific PDEs that could have therapeutic potential in HF.

Successful conservative management of left ventricular assist device candidates

AIMS

Clinical trials comparing LVADs vs. conservative therapy were performed before the availability of novel medications or used suboptimal medical therapy. This study aimed to report that long-term stabilization of patients entering a left ventricular assist device (LVAD) programme is possible with the use of aggressive conservative therapy. This is important because the excellent clinical stabilization provided by LVADs comes at the expense of significant complications.

METHODS AND RESULTS

This study was a single-centre prospective evaluation of consecutive patients with advanced heart failure (HF) fulfilling criteria for LVAD implantation based on clinical and echocardiographic characteristics, cardiopulmonary exercise test, and right heart catheterization results. Their initial therapy included inotropes, thiamine, beta-blockers, digoxin, spironolactone, hydralazine, and nitrates followed by the introduction of novel HF therapies. Coronary revascularization and cardiac resynchronization therapy were performed when indicated, and all patients were closely followed at our outpatient clinic. During the study period, 28 patients were considered suitable for LVAD implantation (mean age 63 ± 10.8 years, 92% men, 78% ischaemic, median HF duration 4 years). Clinical stabilization was achieved and maintained in 21 patients (median follow-up 20 months, range 9-38 months). Compared with baseline evaluation, cardiac index increased from 2.05 (1.73-2.28) to 2.88 (2.63-3.55) L/min/m² , left ventricular end-diastolic diameter decreased from 65.5 (62.4-66) to 58.3 (53.8-62.5) mm, and maximal oxygen consumption increased from 10.1 (9.2-11.3) to 16.1 (15.3-19) mL/kg/min. Three patients died and only four ultimately required LVAD implantation.

CONCLUSIONS

Notwithstanding the small size of our cohort, our results suggest that LVAD implantation could be safely deferred in the majority of LVAD candidates.

Oral enoximone allows the reduction and discontinuation of inhaled steroids and beta2 agonists in asthmatic children

In the last two decades, improvement on asthma treatment has been merely marginal for both adults and children; inhaled corticosteroids (ICS) combined with β-2-mimetics remain the main therapy [3,4]. "New" therapies are just variations on ICS or, for children, on various other drugs that were allowed for adult asthma patients (clinicaltrials.gov). Although currently monoclonal antibodies have been introduced to the field, there is still a large therapeutic burden, given the mortality rate and widespread prevalence of uncontrolled asthma [2]. A simple and adequate way to reduce distress and costs would have great merit. PDE3 inhibitor enoximone was used earlier in successful treatment of life-threatening bronchial asthma (status asthmaticus) as well as in preoperative settings to prevent patients with severe asthma from suffering major surgery-related exacerbations; also, translational mice models showed the anti-inflammatory effects when PDE3 was targeted. Both outcomes suggested a beneficial effect of enoximone in severe chronic asthma. We hypothesized that enoximone might also be helpful in patients with severe chronic asthma; hence, we treated (and followed) > 70 patients (age 0-77, all volunteers) with personalized low doses of enoximone (orally), among them 11 minors, who are described here. Both children and adults reported improvement and/or alleviation of their asthma symptoms. All patients reported a better quality of life and greater drug compliance. The drug was well tolerated and showed no/negligible side effects. Notable bonus: asthma-related comorbidities (allergies, eczema, and rhinitis) were reported also to be less severe or even to disappear. The evaluation shows that PDE3 inhibitor enoximone is an adequate alternative for or addition to current asthma therapeutics, as add-on as well as stand-alone, considerably reducing the use of β-2-mimetics/ICS, with no or negligible side effects. Additional studies are advisable.

Advanced heart failure: guideline-directed medical therapy, diuretics, inotropes, and palliative care

Heart failure (HF) is a major cause of mortality, hospitalizations, and reduced quality of life and a major burden for the healthcare system. The number of patients that progress to an advanced stage of HF is growing. Only a limited proportion of these patients can undergo heart transplantation or mechanical circulatory support. The purpose of this review is to summarize medical management of patients with advanced HF. First, evidence-based oral treatment must be implemented although it is often not tolerated. New therapeutic options may soon become possible for these patients. The second goal is to lessen the symptomatic burden through both decongestion and haemodynamic improvement. Some new treatments acting on cardiac function may fulfil both these needs. Inotropic agents acting through an increase in intracellular calcium have often increased risk of death. However, in the recent Global Approach to Lowering Adverse Cardiac Outcomes Through Improving Contractility in Heart Failure (GALACTIC-HF) trial, omecamtiv mecarbil was safe and effective in the reduction of the primary outcome of cardiovascular death or HF event compared with placebo (hazard ratio, 0.92; 95% confidence interval, 0.86-0.99; P = 0.03) and its effects were larger in those patients with more severe left ventricular dysfunction. Patients with severe HF who received omecamtiv mecarbil experienced a significant treatment benefit, whereas patients without severe HF did not (P = 0.005 for interaction). Lastly, clinicians should take care of the end of life with an appropriate multidisciplinary approach. Medical treatment of advanced HF therefore remains a major challenge and a wide open area for further research.

Developments in Exercise Capacity Assessment in Heart Failure Clinical Trials and the Rationale for the Design of METEORIC-HF

Heart failure with reduced ejection fraction (HFrEF) is a highly morbid condition for which exercise intolerance is a major manifestation. However, methods to assess exercise capacity in HFrEF vary widely in clinical practice and in trials. We describe advances in exercise capacity assessment in HFrEF and a comparative analysis of how various therapies available for HFrEF impact exercise capacity. Current guideline-directed medical therapy has indirect effects on cardiac performance with minimal impact on measured functional capacity. Omecamtiv mecarbil is a novel selective cardiac myosin activator that directly increases cardiac contractility and in a phase 3 cardiovascular outcomes study significantly reduced the primary composite end point of time to first heart failure event or cardiovascular death in patients with HFrEF. The objective of the METEORIC-HF trial (Multicenter Exercise Tolerance Evaluation of Omecamtiv Mecarbil Related to Increased Contractility in Heart Failure) is to assess the effect of omecamtiv mecarbil versus placebo on multiple components of functional capacity in HFrEF. The primary end point is to test the effect of omecamtiv mecarbil compared with placebo on peak oxygen uptake as measured by cardiopulmonary exercise testing after 20 weeks of treatment. METEORIC-HF will provide state-of-the-art assessment of functional capacity by measuring ventilatory efficiency, circulatory power, ventilatory anaerobic threshold, oxygen uptake recovery kinetics, daily activity, and quality-of-life assessment. Thus, the METEORIC-HF trial will evaluate the potential impact of increased myocardial contractility with omecamtiv mecarbil on multiple important measures of functional capacity in ambulatory patients with symptomatic HFrEF. Registration: URL: https://clinicaltrials.gov; Unique identifier: NCT03759392.

Contemporary Drug Treatment of Advanced Heart Failure with Reduced Ejection Fraction

The introduction of multiple new pharmacological agents over the past three decades in the field of heart failure with reduced ejection fraction (HFrEF) has led to reduced rates of mortality and hospitalizations, and consequently the prevalence of HFrEF has increased, and up to 10% of patients progress to more advanced stages, characterized by high rates of mortality, hospitalizations, and poor quality of life. Advanced HFrEF patients often show persistent or progressive signs of severe HF symptoms corresponding to New York Heart Association class III or IV despite being on optimal medical, surgical, and device therapies. However, a subpopulation of patients with advanced HF, those with the most advanced stages of disease, were often insufficiently represented in the major trials demonstrating efficacy and tolerability of the drugs used in HFrEF due to exclusion criteria such as low BP and kidney dysfunction. Consequently, the results of many landmark trials cannot necessarily be transferred to patients with the most advanced stages of HFrEF. Thus, the efficacy and tolerability of guideline-directed medical therapies in patients with the most advanced stages of HFrEF often remain unsettled, and this knowledge is of crucial importance in the planning and timing of consideration for referral for advanced therapies. This review discusses the evidence regarding the use of contemporary drugs in the advanced HFrEF population, covering components such as guideline HFrEF drugs, diuretics, inotropes, and the use of HFrEF drugs in LVAD recipients, and provides suggestions on how to manage guideline-directed therapy in this patient group.

Continuous-flow left ventricular assist device: Current knowledge, complications, and future directions

Long-term continuous-flow left ventricular assist devices have become a real alternative to heart transplantation in patients with advanced heart failure, achieving a promising 2-year event-free survival rate with new-generation devices. Currently, this technology has spread throughout the world, and any cardiologist or cardiac surgeon should be familiar with its fundamentals and its possible complications as well as the advances made in recent years. The aim of this review is to describe current knowledge, management of complications, and future directions of this novel heart-failure therapy.

Evaluation of Real-Life Investigational Use of Enoximone in Asthma, the Third Step in Drug Repurposing: A Preliminary Report

Background

The population of uncontrolled asthma patients represents a large therapeutic burden. The PDE3-inhibitor enoximone is a strong and quick bronchodilator and is known to successfully treat life-threatening bronchial asthma (status asthmaticus). Translational mice models showed anti-inflammatory effects when PDE3 was targeted.

Methods

Here, we investigated the effectiveness of PDE3-inhibitor enoximone as oral treatment for chronic asthma in a real-life off-label setting. Investigational use of PDE3-inhibitor enoximone: 51 outpatients (age 18-77) with chronic asthma were followed using off-label personalized low doses of the PDE3-inhibitor enoximone. Duration of treatment was 2-8 years.

Results

Four groups could be distinguished as follows: The first group includes patients who use enoximone as an add-on, because it helps them in maintaining a better general wellbeing; they still use their traditional medication (n = 5). The second group consists of patients who use enoximone and were able to phase down their traditional medication without deterioration of their asthma symptoms (n = 11). The third group comprises patients who were able to discontinue their traditional medication and use only enoximone without deterioration of their asthma symptoms (n = 24). The last one has patients who, after having used enoximone for some time, saw their symptoms disappear and now use no medication at all, not even enoximone (n = 11). All patients reported improvement or at least alleviation of their asthma symptoms. All patients reported a better quality of life and greater drug compliance.

Conclusion

The evaluation shows that PDE3-inhibitor enoximone is a viable alternative for or addition to current asthma therapeutics, as both add-on and stand-alone, considerably reducing the use of LABAs/SABAs/ICS, with no or negligible side effects. Additional studies are advisable.

Soluble Guanylate Cyclase Stimulators in Heart Failure

Heart failure has a high global burden of morbidity and mortality. Despite significant advances in medical management of heart failure, the prognosis remains poor. This justifies the search for newer therapeutic agents. Recently, soluble guanylate stimulators have demonstrated favorable results in clinical trials. This article aims to summarize the guanylate cyclase signaling pathway, the role of soluble guanylate cyclase stimulators in heart failure, and data from recent clinical trials of these drugs. We concluded that soluble guanylate cyclase stimulators have significant benefits in reducing hospitalizations in patients with heart failure with reduced ejection fraction that are at high risk of cardiovascular events. There appears to be no benefit of these drugs in patients with heart failure with preserved ejection fraction.

Assessment of Omecamtiv Mecarbil for the Treatment of Patients With Severe Heart Failure: A Post Hoc Analysis of Data From the GALACTIC-HF Randomized Clinical Trial

Importance

Heart failure with reduced ejection fraction is a progressive clinical syndrome, and many patients' condition worsen over time despite treatment. Patients with more severe disease are often intolerant of available medical therapies.

Objective

To evaluate the efficacy and safety of omecamtiv mecarbil for the treatment of patients with severe heart failure (HF) enrolled in the Global Approach to Lowering Adverse Cardiac Outcomes Through Improving Contractility in Heart Failure (GALACTIC-HF) randomized clinical trial.

Design, Setting, and Participants

The GALACTIC-HF study was a global double-blind, placebo-controlled phase 3 randomized clinical trial that was conducted at multiple centers between January 2017 and August 2020. A total of 8232 patients with symptomatic HF (defined as New York Heart Association symptom class II-IV) and left ventricular ejection fraction of 35% or less were randomized to receive omecamtiv mecarbil or placebo and followed up for a median of 21.8 months (range, 15.4-28.6 months). The current post hoc analysis evaluated the efficacy and safety of omecamtiv mecarbil therapy among patients classified as having severe HF compared with patients without severe HF. Severe HF was defined as the presence of all of the following criteria: New York Heart Association symptom class III to IV, left ventricular ejection fraction of 30% or less, and hospitalization for HF within the previous 6 months.

Interventions

Participants were randomized at a 1:1 ratio to receive either omecamtiv mecarbil or placebo.

Main Outcomes and Measures

The primary end point was time to first HF event or cardiovascular (CV) death. Secondary end points included time to CV death and safety and tolerability.

Results

Among 8232 patients enrolled in the GALACTIC-HF clinical trial, 2258 patients (27.4%; mean [SD] age, 64.5 [11.6] years; 1781 men [78.9%]) met the specified criteria for severe HF. Of those, 1106 patients were randomized to the omecamtiv mecarbil group and 1152 to the placebo group. Patients with severe HF who received omecamtiv mecarbil experienced a significant treatment benefit for the primary end point (hazard ratio [HR], 0.80; 95% CI, 0.71-0.90), whereas patients without severe HF had no significant treatment benefit (HR, 0.99; 95% CI, 0.91-1.08; P = .005 for interaction). For CV death, the results were similar (HR for patients with vs without severe HF: 0.88 [95% CI, 0.75-1.03] vs 1.10 [95% CI, 0.97-1.25]; P = .03 for interaction). Omecamtiv mecarbil therapy was well tolerated in patients with severe HF, with no significant changes in blood pressure, kidney function, or potassium level compared with placebo.

Conclusions and Relevance

In this post hoc analysis of data from the GALACTIC-HF clinical trial, omecamtiv mecarbil therapy may have provided a clinically meaningful reduction in the composite end point of time to first HF event or CV death among patients with severe HF. These data support a potential role of omecamtiv mecarbil therapy among patients for whom current treatment options are limited.

Trial Registration

ClinicalTrials.gov Identifier: NCT02929329.

Meta-Analysis of Placebo-Controlled Trials of Levosimendan in Acute Myocardial Infarction

The treatment of acute myocardial infarction is early revascularization. Heart failure and cardiogenic shock may complicate acute myocardial infarction despite applying the best available strategy. Levosimendan is a relatively new drug to treat heart failure with a peculiar mechanism of action: calcium sensitization of myocardial fibres. Levosimendan has a direct inotropic effect but also pleiotropic effects; through the K+ATP channel's opening, it also has a vasodilator effect which may participate concretely in the global effects of the drug. The focus of the literature is on the anti-heart failure and anti-cardiogenic shock properties of Levosimendan, but it may have effects also preventing the development of myocardial insufficiency in acute myocardial infarction. The aim of the meta-analysis is to evaluate the effect of Levosimendan on acute myocardial infarction in placebo-controlled trials. Based on the eight studies selected, we found a beneficial effect of Levosimendan on acute and long-term mortality of patients affected by acute myocardial infarction. With caution in interpreting the results of this meta-analysis, our data support the idea that Levosimendan may already have a role in the treatment of acute ischemic heart disease. Further studies specifically designed to investigate the early role in the treatment of ischemic heart failure are needed.

Socioeconomic Disparities in Referral for Invasive Hemodynamic Evaluation for Advanced Heart Failure: A Nationwide Cohort Study

BACKGROUND

Factors determining referral for advanced heart failure (HF) evaluation are poorly studied. We studied the influence of socioeconomic aspects on the referral process in Denmark, which has a taxpayer-funded national health care system.

METHODS

We identified all patients aged 18 to 75 years with a first diagnosis of HF during 2010 to 2018. Hospitalized patients had to be discharged alive and were then followed for the outcome of undergoing a right heart catheterization (RHC) used as a surrogate marker of advanced HF work-up.

RESULTS

Of 36 637 newly diagnosed patients with HF, 680 (1.9%) underwent RHC during the follow-up period (median time to RHC of 280 days [interquartile range, 73-914]). Factors associated with a higher likelihood of RHC included the highest versus lowest household income quartile (HR, 1.56 [95% CI, 1.19-2.06]; P=0.001), being diagnosed with HF at a tertiary versus nontertiary hospital (HR, 1.68 [95% CI, 1.37-2.05]; P<0.001) and during a hospitalization versus outpatient visit (HR, 1.67 [95% CI, 1.42-1.95]; P<0.001). Level of education, occupational status, and distance to tertiary hospital were not independently associated with RHC. Older age, cancer, and a psychiatric diagnosis were independently associated with a decreased probability of RHC.

CONCLUSIONS

Higher household income, HF diagnosis during hospitalization, and first admission at a tertiary hospital were associated with increased likelihood of subsequent referral for RHC independent of other demographic and clinical variables. Greater attention may be required to ensure timely referral for advanced HF therapies in lower income groups.

Phosphodiesterase-4 Inhibitors for Non-COPD Respiratory Diseases

Selective phosphodiesterase (PDE) inhibitors are a class of nonsteroid anti-inflammatory drugs for treating chronic inflammatory diseases. Modulation of systemic and airway inflammation is their pivotal mechanism of action. Furthermore, PDE inhibitors modulate cough reflex and inhibit airway mucus secretion. Roflumilast, a selective PDE4 inhibitor, has been extensively studied for the efficacy and safety in chronic obstructive pulmonary disease (COPD) patients. According to the mechanisms of action, the potential roles of PDE inhibitors in treating chronic respiratory diseases including severe asthma, asthma-COPD overlap (ACO), noncystic fibrosis bronchiectasis, and chronic cough are discussed. Since roflumilast inhibits airway eosinophilia and neutrophilia in COPD patients, it reduces COPD exacerbations in the presence of chronic bronchitis in addition to baseline therapies. The clinical studies in asthma patients have shown the comparable efficacy of roflumilast to inhaled corticosteroids for improving lung function. However, the clinical trials of roflumilast in severe asthma have been limited. Although ACO is common and is also associated with poor outcomes, there is no clinical trial regarding its efficacy in patients with ACO despite a promising role in reducing COPD exacerbation. Since mucus hypersecretion is a result of neutrophil secretagogue in patients with chronic bronchitis, experimental studies have shown that PDE4s are regulators of the cystic fibrosis transmembrane conductance regulator (CFTR) in human airway epithelial cells. Besides, goblet cell hyperplasia is associated with an increased expression of PDE. Bronchiectasis and chronic bronchitis are considered neutrophilic airway diseases presenting with mucus hypersecretion. They commonly coexist and thus lead to severe disease. The role of roflumilast in noncystic fibrosis bronchiectasis is under investigation in clinical trials. Lastly, PDE inhibitors have been shown modulating cough from bronchodilation, suppressing transient receptors potential (TRP), and anti-inflammatory properties. Hence, there is the potential role of the drug in the management of unexplained cough. However, clinical trials for examining its antitussive efficacy are pivotal. In conclusion, selective PDE4 inhibitors may be potential treatment options for chronic respiratory diseases apart from COPD due to their promising mechanisms of action.

From Genetic Mutations to Molecular Basis of Heart Failure Treatment: An Overview of the Mechanism and Implication of the Novel Modulators for Cardiac Myosin

Heart failure (HF) is a syndrome encompassing several important etiologies that lead to the imbalance between oxygen demand and supply. Despite the usage of guideline-directed medical therapy for HF has shown better outcomes, novel therapeutic strategies are desirable, especially for patients with preserved or mildly reduced left ventricular ejection fraction. In this regard, understanding the molecular basis for cardiomyopathies is expected to fill in the knowledge gap and generate new therapies to improve prognosis for HF. This review discusses an evolutionary mechanism designed to regulate cardiac contraction and relaxation through the most often genetically determined cardiomyopathies associated with HF. In addition, both the myosin inhibitor and myosin activator are promising new treatments for cardiomyopathies. A comprehensive review from genetic mutations to the molecular basis of direct sarcomere modulators will help shed light on future studies for a better characterization of HF etiologies and potential therapeutic targets.

An update on levosimendan in acute cardiac care: applications and recommendations for optimal efficacy and safety

Introduction: In the 20 years since its introduction to the palette of intravenous hemodynamic therapies, the inodilator levosimendan has established itself as a valuable asset for the management of acute decompensated heart failure. Its pharmacology is notable for delivering inotropy via calcium sensitization without an increase in myocardial oxygen consumption.Areas covered: Experience with levosimendan has led to its applications expanding into perioperative hemodynamic support and various critical care settings, as well as an array of situations associated with acutely decompensated heart failure, such as right ventricular failure, cardiogenic shock with multi-organ dysfunction, and cardio-renal syndrome. Evidence suggests that levosimendan may be preferable to milrinone for patients in cardiogenic shock after cardiac surgery or for weaning from extracorporeal life support and may be superior to dobutamine in terms of short-term survival, especially in patients on beta-blockers. Positive effects on kidney function have been noted, further differentiating levosimendan from catecholamines and phosphodiesterase inhibitors.Expert opinion:Levosimendan can be a valuable resource in the treatment of acute cardiac dysfunction, especially in the presence of beta-blockers or ischemic cardiomyopathy. When attention is given to avoiding or correcting hypovolemia and hypokalemia, an early use of the drug in the treatment algorithm is preferred.

PDE3-inhibitor enoximone prevented mechanical ventilation in patients with SARS-CoV-2 pneumonia

BACKGROUND

Standard care in severe SARS-CoV-2 pneumonia complicated by severe dyspnea and respiratory failure, consists of symptom reduction, ultimately supported by mechanical ventilation. Patients with severe SARS-CoV-2, a prominent feature of COVID-19, show several similar symptoms to Critical Asthma Syndrome (CAS) patients, such as pulmonary edema, mucus plugging of distal airways, decreased tissue oxygenation, (emergent) exhaustion due to severe dyspnea and respiratory failure. Prior application of elective phosphodiesterase (PDE)3-inhibitors milrinone and enoximone in patients with CAS yielded rapid symptomatic relief and reverted the need for mechanical ventilation, due to their bronchodilator and anti-inflammatory properties. Based on these observations, we hypothesized that enoximone may be beneficial in the treatment of patients with severe SARS-CoV-2 pneumonia and prominent CAS-features.

METHODS

In this case report enoximone was administered to four consecutive patients (1 M; 3 F; 46-70 y) with emergent respiratory failure due to SARS-CoV-2 pneumonia. Clinical outcome was compared with three controls who received standard care only.

RESULTS

After an intravenous bolus of enoximone 20 mg followed by 10 mg/h via perfusor, a rapid symptomatic relief was observed: two out of four patients recovered within a few hours, the other two (with comorbid COPD GOLD II/III) responded within 24-36 h. Compared to the controls, in the enoximone-treated patients respiratory failure and further COVID-19-related deterioration was reverted and mechanical ventilation was prevented, leading to reduced hospital/ICU time.

DISCUSSION

Our preliminary observations suggest that early intervention with the selective PDE3-inhibitor enoximone may help to revert respiratory failure as well as avert mechanical ventilation, and reduces ICU/hospital time in patients with severe SARS-CoV-2 pneumonia. Our findings warrant further research on the therapeutic potential of PDE3-inhibition, alone or in combination with other anti-COVID-19 strategies.

Targeting Cyclic Guanosine Monophosphate to Treat Heart Failure: JACC Review Topic of the Week

The significant morbidity and mortality associated with heart failure with reduced ejection fraction (HFrEF) or heart failure with preserved ejection fraction (HFpEF) justify the search for novel therapeutic agents. Reduced cyclic guanosine monophosphate levels contribute to HF progression. Among molecules modulating the nitric oxide (NO)-GMP-phosphodiesterase (PDE) pathway, the evaluation of nitrates, synthetic natriuretic peptides (NP), and NP analogs has yielded mixed results. Conversely, sacubitril/valsartan, combining NP degradation inhibition through neprilysin and angiotensin receptor blockade, has led to groundbreaking findings in HFrEF. Other strategies to increase tissue cyclic guanosine monophosphate have been attempted, such as PDE-3 or PDE-5 inhibition (with negative or neutral results), NO-independent soluble guanylate cyclase (sGC) activation, or enhancement of sGC sensitivity to endogenous NO. Following the positive results of the phase 3 VICTORIA (A Study of Vericiguat in Participants With Heart Failure With Reduced Ejection Fraction) trial on the sGC stimulator vericiguat in HFrEF, the main open questions are the efficacy of the sacubitril/valsartan-vericiguat combination in HFrEF and of vericiguat in HFpEF.

Myocardial Phosphodiesterases and Their Role in cGMP Regulation

Cyclic nucleotide phosphodiesterases comprise an 11-member superfamily yielding near 100 isoform variants that hydrolyze cAMP or cGMP to their respective 5'-monophosphate form. Each plays a role in compartmentalized cyclic nucleotide signaling, with varying selectivity for each substrate, and conveying cell and intracellular-specific localized control. This review focuses on the 5 phosphodiesterases (PDEs) expressed in the cardiac myocyte capable of hydrolyzing cGMP and that have been shown to play a role in cardiac physiological and pathological processes. PDE1, PDE2, and PDE3 catabolize cAMP as well, whereas PDE5 and PDE9 are cGMP selective. PDE3 and PDE5 are already in clinical use, the former for heart failure, and PDE1, PDE9, and PDE5 are all being actively studied for this indication in patients. Research in just the past few years has revealed many novel cardiac influences of each isoform, expanding the therapeutic potential from their selective pharmacological blockade or in some instances, activation. PDE1C inhibition was found to confer cell survival protection and enhance cardiac contractility, whereas PDE2 inhibition or activation induces beneficial effects in hypertrophied or failing hearts, respectively. PDE3 inhibition is already clinically used to treat acute decompensated heart failure, although toxicity has precluded its long-term use. However, newer approaches including isoform-specific allosteric modulation may change this. Finally, inhibition of PDE5A and PDE9A counter pathological remodeling of the heart and are both being pursued in clinical trials. Here, we discuss recent research advances in each of these PDEs, their impact on the myocardium, and cardiac therapeutic potential.

(Oral) enoximone in asthma

The Enoximone in status asthmaticus letter [1] referenced our case series from the Netherlands wherein intravenous enoximone (Perfan, Carinopharm, Germany) reversed status asthmaticus in eight patients [2]. Schulzet al. [1] end their letter with the statement that further research is called for; this correspondence is to indicate that research has been carried out and is still ongoing.

PDE-3 inhibitors appear to have a large therapeutic value in asthma treatment; this letter provides some of the insights acquired in recent researchhttps://bit.ly/33D9Dgd

Sacubitril/Valsartan in Advanced Heart Failure With Reduced Ejection Fraction: Rationale and Design of the LIFE Trial

The PARADIGM-HF (Prospective Comparison of Angiotensin II Receptor Blocker Neprilysin Inhibitor With Angiotensin-Converting Enzyme Inhibitor to Determine Impact on Global Mortality and Morbidity in Heart Failure) trial reported that sacubitril/valsartan (S/V), an angiotensin receptor-neprilysin inhibitor, significantly reduced mortality and heart failure (HF) hospitalization in HF patients with a reduced ejection fraction (HFrEF). However, fewer than 1% of patients in the PARADIGM-HF study had New York Heart Association (NYHA) functional class IV symptoms. Accordingly, data that informed the use of S/V among patients with advanced HF were limited. The LIFE (LCZ696 in Hospitalized Advanced Heart Failure) study was a 24-week prospective, multicenter, double-blinded, double-dummy, active comparator trial that compared the safety, efficacy, and tolerability of S/V with those of valsartan in patients with advanced HFrEF. The trial planned to randomize 400 patients ≥18 years of age with advanced HF, defined as an EF ≤35%, New York Heart Association functional class IV symptoms, elevated natriuretic peptide concentration (B-type natriuretic peptide [BNP] ≥250 pg/ml or N-terminal pro-B-type natriuretic peptide [NT-proBNP] ≥800 pg/ml), and ≥1 objective finding of advanced HF. Following a 3- to 7-day open label run-in period with S/V (24 mg/26 mg twice daily), patients were randomized 1:1 to S/V titrated to 97 mg/103 mg twice daily versus 160 mg of V twice daily. The primary endpoint was the proportional change from baseline in the area under the curve for NT-proBNP levels measured through week 24. Secondary and tertiary endpoints included clinical outcomes and safety and tolerability. Because of the COVID-19 pandemic, enrollment in the LIFE trial was stopped prematurely to ensure patient safety and data integrity. The primary analysis consists of the first 335 randomized patients whose clinical follow-up examination results were not severely impacted by COVID-19. (Entresto [LCZ696] in Advanced Heart Failure [LIFE STUDY] [HFN-LIFE]; NCT02816736).

Cardiac Cyclic Nucleotide Phosphodiesterases: Roles and Therapeutic Potential in Heart Failure

The cyclic nucleotides cyclic adenosine-3′,5′-monophosphate (cAMP) and cyclic guanosine-3′,5′-monophosphate (cGMP) maintain physiological cardiac contractility and integrity. Cyclic nucleotide–hydrolysing phosphodiesterases (PDEs) are the prime regulators of cAMP and cGMP signalling in the heart. During heart failure (HF), the expression and activity of multiple PDEs are altered, which disrupt cyclic nucleotide levels and promote cardiac dysfunction. Given that the morbidity and mortality associated with HF are extremely high, novel therapies are urgently needed. Herein, the role of PDEs in HF pathophysiology and their therapeutic potential is reviewed. Attention is given to PDEs 1–5, and other PDEs are briefly considered. After assessing the role of each PDE in cardiac physiology, the evidence from pre-clinical models and patients that altered PDE signalling contributes to the HF phenotype is examined. The potential of pharmacologically harnessing PDEs for therapeutic gain is considered.

The effect of milrinone on mortality in adult patients who underwent CABG surgery: a systematic review of randomized clinical trials with a meta-analysis and trial sequential analysis

Background

As an inodilator, milrinone is commonly used for patients who undergo coronary artery bypass graft (CABG) surgery because of its effectiveness in decreasing the cardiac index and mitral regurgitation. The aim of this study was to perform a systematic review and meta-analysis of existing studies from the past 20 years to evaluate the impact of milrinone on mortality in patients who undergo CABG surgery.

Methods

We performed a systematic literature search on the application of milrinone in patients who underwent CABG surgery in studies published between 1997 and 2017 in BioMed Central, PubMed, EMBASE, and the Cochrane Central Register. The included studies evaluated milrinone groups compared to groups receiving either placebo or standard treatment and further compared the systemic administration.

Results

The network meta-analysis included 723 patients from 16 randomized clinical trials. Overall, there was no significant difference in mortality between the milrinone group and the placebo/standard care group when patients underwent CABG surgery. In addition, 9 trials (with 440 randomized patients), 4 trials (with 212 randomized patients), and 10 trials (with 470 randomized patients) reported that the occurrence of myocardial infarction (MI), myocardial ischemia, and arrhythmia was lower in the milrinone group than in the placebo/standard care group. Between the milrinone treatment and placebo/standard care groups, the occurrence of myocardial infarction, myocardial ischemia, and arrhythmia was significantly different. However, the occurrence of stroke and renal failure, the duration of inotropic support (h), the need for an intra-aortic balloon pump (IABP), and mechanical ventilation (h) between these two groups showed no differences.

Conclusions

Based on the current results, compared with placebo, milrinone might be unable to decrease mortality in adult CABG surgical patients but can significantly ameliorate the occurrence of MI, myocardial ischemia, and arrhythmia. These results provide evidence for the further clinical application of milrinone and of therapeutic strategies for CABG surgery. However, along with milrinone application in clinical use, sufficient data from randomized clinical trials need to be collected, and the potential benefits and adverse effects should be analyzed and reevaluated.

PDE3 Inhibition Reduces Epithelial Mast Cell Numbers in Allergic Airway Inflammation and Attenuates Degranulation of Basophils and Mast Cells

Epithelial mast cells are generally present in the airways of patients with allergic asthma that are inadequately controlled. Airway mast cells (MCs) are critically involved in allergic airway inflammation and contribute directly to the main symptoms of allergic patients. Phosphodiesterase 3 (PDE3) tailors signaling of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), which are critical intracellular second messenger molecules in various signaling pathways. This paper investigates the pathophysiological role and disease-modifying effects of PDE3 in mouse bone marrow-derived MCs (bmMCs), human LAD2- and HMC1 mast cell lines, human blood basophils, and peripheral blood-derived primary human MCs (HuMCs). In a chronic house dust mite (HDM)-driven allergic airway inflammation mouse model, we observed that PDE3 deficiency or PDE3 inhibition (PDE3i) therapy reduced the numbers of epithelial MCs, when compared to control mice. Mouse bone marrow-derived MCs (bmMCs) and the human HMC1 and LAD2 cell lines predominantly expressed PDE3B and PDE4A. BmMCs from Pde3^−/− mice showed reduced loss of the degranulation marker CD107b compared with wild-type BmMCs, when stimulated in an immunoglobulin E (IgE)-dependent manner. Following both IgE-mediated and substance P-mediated activation, PDE3i-pretreated basophils, LAD2 cells, and HuMCs, showed less degranulation than diluent controls, as measured by surface CD63 expression. MCs lacking PDE3 or treated with the PDE3i enoximone exhibited a lower calcium flux upon stimulation with ionomycine. In conclusion PDE3 plays a critical role in basophil and mast cell degranulation and therefore its inhibition may be a treatment option in allergic disease.

A PDE3A Promoter Polymorphism Regulates cAMP-Induced Transcriptional Activity in Failing Human Myocardium

BACKGROUND

The phosphodiesterase 3A (PDE3A) gene encodes a PDE that regulates cardiac myocyte cyclic adenosine monophosphate (cAMP) levels and myocardial contractile function. PDE3 inhibitors (PDE3i) are used for short-term treatment of refractory heart failure (HF), but do not produce uniform long-term benefit.

OBJECTIVES

The authors tested the hypothesis that drug target genetic variation could explain clinical response heterogeneity to PDE3i in HF.

METHODS

PDE3A promoter studies were performed in a cloned luciferase construct. In human left ventricular (LV) preparations, mRNA expression was measured by reverse transcription polymerase chain reaction, and PDE3 enzyme activity by cAMP-hydrolysis.

RESULTS

The authors identified a 29-nucleotide (nt) insertion (INS)/deletion (DEL) polymorphism in the human PDE3A gene promoter beginning 2,214 nt upstream from the PDE3A1 translation start site. Transcription factor ATF3 binds to the INS and represses cAMP-dependent promoter activity. In explanted failing LVs that were homozygous for PDE3A DEL and had been treated with PDE3i pre-cardiac transplantation, PDE3A1 mRNA abundance and microsomal PDE3 enzyme activity were increased by 1.7-fold to 1.8-fold (p < 0.05) compared with DEL homozygotes not receiving PDE3i. The basis for the selective up-regulation in PDE3A gene expression in DEL homozygotes treated with PDE3i was a cAMP response element enhancer 61 nt downstream from the INS, which was repressed by INS. The DEL homozygous genotype frequency was also enriched in patients with HF.

CONCLUSIONS

A 29-nt INS/DEL polymorphism in the PDE3A promoter regulates cAMP-induced PDE3A gene expression in patients treated with PDE3i. This molecular mechanism may explain response heterogeneity to this drug class, and may inform a pharmacogenetic strategy for a more effective use of PDE3i in HF.

Haemodynamic Balance in Acute and Advanced Heart Failure: An Expert Perspective on the Role of Levosimendan

Acute and advanced heart failure are associated with substantial adverse short- and longer-term prognosis. Both conditions necessitate complex treatment choices to restore haemodynamic stability and organ perfusion, relieve congestion, improve symptoms and allow the patient to leave the hospital and achieve an adequate quality of life. Among the available intravenous vasoactive therapies, inotropes constitute an option when an increase in cardiac contractility is needed to reverse a low output state. Within the inotrope category, levosimendan is well suited to the needs of both sets of patients since, in contrast to conventional adrenergic inotropes, it has not been linked in clinical trials or wider clinical usage with increased mortality risk and retains its efficacy in the presence of beta-adrenergic receptor blockade; it is further believed to possess beneficial renal effects. The overall haemodynamic profile and clinical tolerability of levosimendan, combined with its extended duration of action, have encouraged its intermittent use in patients with advanced heart failure. This paper summarises the key messages derived from a series of 12 tutorials held at the Heart Failure 2019 congress organised in Athens, Greece, by the Heart Failure Association of the European Society of Cardiology.

Hemodynamic effects of inotropic drugs in heart failure: A network meta-analysis of clinical trials

BACKGROUND

There is currently no consensus on the appropriate selection of inotropic therapy in ventricular dysfunction. The objective of the study was to detect the effects of different inotropes on the hemodynamics of patients who developed low cardiac output.

METHODS

PubMed, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched (all updated December 31, 2017). The inclusion criteria were as follows: low cardiac index (CI < 2.5 L/min/m) or New York Heart Association class II-IV, and at least 1 group receiving an inotropic drug compared to another group receiving a different inotropic/placebo treatment. The exclusion criteria were studies published as an abstract only, crossover studies, and studies with a lack of data on the cardiac index.

RESULTS

A total of 1402 patients from 37 trials were included in the study. Inotropic drugs were shown to increase the cardiac index (0.32, 95%CI:0.25, 0.38), heart rate (7.68, 95%CI:6.36, 9.01), and mean arterial pressure (3.17, 95%CI:1.96, 4.38) than the placebo. Overall, the pooled estimates showed no difference in terms of cardiac index, heart rate, mean arterial pressure, systemic vascular resistance, and mean pulmonary arterial pressure among the groups receiving different inotropes.

CONCLUSIONS

Our systematic review found that inotrope therapy is not associated with the amelioration of hemodynamics. An accurate evaluation of the benefits and risks, and selection of the correct inotropic agent is required in all clinical settings.

Why has positive inotropy failed in chronic heart failure? Lessons from prior inotrope trials

Current pharmacological therapies for heart failure with reduced ejection fraction are largely either repurposed anti‐hypertensives that blunt overactivation of the neurohormonal system or diuretics that decrease congestion. However, they do not address the symptoms of heart failure that result from reductions in cardiac output and reserve. Over the last few decades, numerous attempts have been made to develop and test positive cardiac inotropes that improve cardiac haemodynamics. However, definitive clinical trials have failed to show a survival benefit. As a result, no positive inotrope is currently approved for long‐term use in heart failure. The focus of this state‐of‐the‐art review is to revisit prior clinical trials and to understand the causes for their findings. Using the learnings from those experiences, we propose a framework for future trials of such agents that maximizes their potential for success. This includes enriching the trials with patients who are most likely to derive benefit, using biomarkers and imaging in trial design and execution, evaluating efficacy based on a wider range of intermediate phenotypes, and collecting detailed data on functional status and quality of life. With a rapidly growing population of patients with advanced heart failure, the epidemiologic insignificance of heart transplantation as a therapeutic intervention, and both the cost and morbidity associated with ventricular assist devices, there is an enormous potential for positive inotropic therapies to impact the outcomes that matter most to patients.

Phase 3 DREAM-HF Trial of Mesenchymal Precursor Cells in Chronic Heart Failure

Advanced heart failure (HF) is a progressive disease characterized by recurrent hospitalizations and high risk of mortality. Indeed, outcomes in late stages of HF approximate those seen in patients with various aggressive malignancies. Clinical trials assessing beneficial outcomes of new treatments in patients with cancer have used innovative approaches to measure impact on total disease burden or surrogates to assess treatment efficacy. Although most cardiovascular outcomes trials continue to use time-to-first event analyses to assess the primary efficacy end point, such analyses do not adequately reflect the impact of new treatments on the totality of the chronic disease burden. Consequently, patient enrichment and other strategies for ongoing clinical trial design, as well as new statistical methodologies, are important considerations, particularly when studying a population with advanced chronic HF. The DREAM-HF trial (Double-Blind Randomized Assessment of Clinical Events With Allogeneic Mesenchymal Precursor Cells in Advanced Heart Failure) is an ongoing, randomized, sham-controlled phase 3 study of the efficacy and safety of mesenchymal precursor cells as immunotherapy in patients with advanced chronic HF with reduced ejection fraction. Mesenchymal precursor cells have a unique multimodal mechanism of action that is believed to result in polarization of proinflammatory type 1 macrophages in the heart to an anti-inflammatory type 2 macrophage state, inhibition of maladaptive adverse left ventricular remodeling, reversal of cardiac and peripheral endothelial dysfunction, and recovery of deranged vasculature. The objective of DREAM-HF is to confirm earlier phase 2 results and evaluate whether mesenchymal precursor cells will reduce the rate of nonfatal recurrent HF-related major adverse cardiac events while delaying or preventing progression of HF to terminal cardiac events. DREAM-HF is an example of an ongoing contemporary events-driven cardiovascular cell-based immunotherapy study that has utilized the concepts of baseline disease enrichment, prognostic enrichment, and predictive enrichment to improve its efficiency by using accumulating data from within as well as external to the trial. Adaptive enrichment designs and strategies are important components of a rational approach to achieve clinical research objectives in shorter clinical trial timelines and with increased cost-effectiveness without compromising ethical standards or the overall statistical integrity of the study. The DREAM-HF trial also presents an alternative approach to traditional composite time-to-first event primary efficacy end points. Statistical methodologies such as the joint frailty model provide opportunities to expand the scope of events-driven HF with reduced ejection fraction clinical trials to utilize time to recurrent nonfatal HF-related major adverse cardiac events as the primary efficacy end point without compromising the integrity of the statistical analyses for terminal cardiac events. In advanced chronic HF with reduced ejection fraction studies, the joint frailty model is utilized to reflect characteristics of the high-risk patient population with important unmet therapeutic needs. In some cases, use of the joint frailty model may substantially reduce sample size requirements. In addition, using an end point that is acceptable to the Food and Drug Administration and the European Medicines Agency, such as recurrent nonfatal HF-related major adverse cardiac events, enables generation of clinically relevant pharmacoeconomic data while providing comprehensive views of the patient's overall cardiovascular disease burden. The major goal of this review is to provide lessons learned from the ongoing DREAM-HF trial that relate to biologic plausibility and flexible clinical trial design and are potentially applicable to other development programs of innovative therapies for patients with advanced cardiovascular disease. Clinical Trial Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02032004.

Focusing on Referral Rather than Selection for Advanced Heart Failure Therapies

Despite advances in heart failure treatment, advanced heart failure affects 5–10% of people with the condition and is associated with poor prognosis. Selection for heart transplantation and left ventricular assist device implantation is a rigorous and validated process performed by specialised heart failure teams. This entails comprehensive assessment of complex diagnostic tests and risk scores, and selecting patients with the optimal benefit-risk profile. In contrast, referral for advanced heart failure evaluation is an arbitrary and poorly studied process, performed by generalists, and patients are often referred too late or not at all. The study elaborates on the differences between selection and referral and proposes some simple strategies for optimising timely referral for advanced heart failure evaluation.

Preliminary results of the Multicenter Observational Study with Enoximone in Cardiac surgery (MOSEC)

BACKGROUND

Perioperative administration of Enoximone has been shown to improve hemodynamics, organ function, and inflammatory response. Aim of the present study was to evaluate the effects of Enoximone after on-pump cardiac surgery.

METHODS

A protocol for a multicenter observational study was reviewed and approved by local ethic committee. This preliminary report involves the first 29 patients enrolled, in whom Enoximone was perioperatively administered in the context of on-pump cardiac surgery. All patients enrolled were propensity-matched 1:1 with controls not receiving Enoximone, renal function was evaluated in terms of estimated glomerular filtration rate (eGFR) with the CKD-EPI equation.

RESULTS

After propensity matching, the two cohorts of patients receiving Enoximone or not did not show any significant differences among baseline characteristics. Patients receiving Enoximone showed a progressive improvement of eGFR at each time-point of follow-up: roughly +4.3, +10.0, and +12.3 mL/min/1.73 m² on postoperative days 2, 7, and 30; respectively. Consistently, maximum difference versus baseline was +12.6 mL/min/1.73 m² (or +19.3%) among Enoximone patients vs +3.3 mL/min/1.73 m² (or +4.4%) among controls (p = 0.02). Multivariable regression analysis (R²-adjusted 0.47) showed only age (β -0.53; p = 0.01), preoperative eGFR (β -0.39; p = 0.02), diabetes (β 2.1; p = 0.01), cardio-pulmonary bypass duration (β 0.08; p = 0.05), and Enoximone administration (β -0.74; p = 0.05) to be independently correlated with delta eGFR variation on day 30.

CONCLUSION

These preliminary results show that perioperative Enoximone administration improved renal function in patients undergoing on-pump cardiac surgery. Further studies are needed to confirm these findings.

Ambulatory Intravenous Inotropic Support and or Levosimendan in Pediatric and Congenital Heart Failure: Safety, Survival, Improvement, or Transplantation

End-stage heart failure (HF) frequently needs continuous inotropic support in hospital and has high morbidity and mortality in absence of heart transplantation. This study reports outcome, efficacy, and safety of continuous ambulatory inotropes (AI) and/or periodic levosimendan (LS) infusions in pediatric HF patients. The study included 27 patients, median age 9.4 (0.1-26.1) years, with severe HF (6 myocarditis, 13 dilated cardiomyopathy, 2 restrictive cardiomyopathy, 6 repaired congenital heart disease). Dobutamine and milrinone AI were administered in 21 patients through a permanent central catheter for median duration 1.0 (0.3-3.7) years. Additionally, 14 AI patients and the remaining 6 study patients received periodic LS infusions for median duration 1.1 (0.2-4.2) years. During median follow-up 2.1 (0.3-21.3) years, 4 patients died of worsening HF after 0.8-2.1 years AI, 6 patients underwent heart transplantation with only 3 survivors, while the rest remained stable out of the hospital with complications 4 line infections treated with antibiotics and 4 catheter reinsertions due to dislodgement. Severe pulmonary hypertension was reversed with AI in 2 patients, allowing successful heart-only transplantation. Therapy with AI was discontinued after 1.4-0.4 years in 6 improved myocarditis and 3 cardiomyopathy patients without deterioration. In conclusion, prolonged AI and/or LS infusions in HF are safe and beneficial even in small infants, allowing stabilization and reasonable social and family life out of the hospital. It may provide precious time for heart transplantation or myocardial remodeling, improvement, and possible discontinuation even after long periods of support.

Extended Release Oral Milrinone, CRD-102, for Advanced Heart Failure

Although heart transplantation and mechanical circulatory support are effective therapies for patients with advanced heart failure (HF), many patients are ineligible due to co-morbidities. Continuous home intravenous with positive inotropes such as milrinone are used in these patients to improve quality of life. We hypothesized that, unlike previous studies with oral milrinone, a slow-release formulation that provides stable lower plasma levels may be better tolerated and provide symptomatic benefit. Accordingly, we developed an extended release milrinone formulation (CRD-102) and evaluated its effects in 26 patients with no-option Stage D HF. One month after open-label therapy there were significant improvements in NYHA class, Minnesota Living with Heart Failure score and 6-minute walk distance. There was no evidence of hypotension or increased arrhythmic burden. In conclusion, the present study demonstrates evidence of beneficial actions of extended release milrinone in advanced HF. Longer-term randomized clinical trial data are required.

A pathophysiological role of PDE3 in allergic airway inflammation

Phosphodiesterase 3 (PDE3) and PDE4 regulate levels of cyclic AMP, which are critical in various cell types involved in allergic airway inflammation. Although PDE4 inhibition attenuates allergic airway inflammation, reported side effects preclude its application as an antiasthma drug in humans. Case reports showed that enoximone, which is a smooth muscle relaxant that inhibits PDE3, is beneficial and lifesaving in status asthmaticus and is well tolerated. However, clinical observations also showed antiinflammatory effects of PDE3 inhibition. In this study, we investigated the role of PDE3 in a house dust mite-driven (HDM-driven) allergic airway inflammation (AAI) model that is characterized by T helper 2 cell activation, eosinophilia, and reduced mucosal barrier function. Compared with wild-type (WT) littermates, mice with a targeted deletion of the PDE3A or PDE3B gene showed significantly reduced HDM-driven AAI. Therapeutic intervention in WT mice showed that all hallmarks of HDM-driven AAI were abrogated by the PDE3 inhibitors enoximone and milrinone. Importantly, we found that enoximone also reduced the upregulation of the CD11b integrin on mouse and human eosinophils in vitro, which is crucial for their recruitment during allergic inflammation. This study provides evidence for a hitherto unknown antiinflammatory role of PDE3 inhibition in allergic airway inflammation and offers a potentially novel treatment approach.

Cardiac Phosphodiesterases and Their Modulation for Treating Heart Disease

An important hallmark of cardiac failure is abnormal second messenger signaling due to impaired synthesis and catabolism of cyclic adenosine 3',5'- monophosphate (cAMP) and cyclic guanosine 3',5'- monophosphate (cGMP). Their dysregulation, altered intracellular targeting, and blunted responsiveness to stimulating pathways all contribute to pathological remodeling, muscle dysfunction, reduced cell survival and metabolism, and other abnormalities. Therapeutic enhancement of either cyclic nucleotides can be achieved by stimulating their synthesis and/or by suppressing members of the family of cyclic nucleotide phosphodiesterases (PDEs). The heart expresses seven of the eleven major PDE subtypes - PDE1, 2, 3, 4, 5, 8, and 9. Their differential control over cAMP and cGMP signaling in various cell types, including cardiomyocytes, provides intriguing therapeutic opportunities to counter heart disease. This review examines the roles of these PDEs in the failing and hypertrophied heart and summarizes experimental and clinical data that have explored the utility of targeted PDE inhibition.

How robust are clinical trials in heart failure?

Aims

Guidelines for the management of chronic heart failure (CHF) cite the results of randomized controlled trials (RCTs) to support treatment recommendations. The significance of an observed treatment-effect relies on the use of a boundary P-value, most commonly P < 0.05. There is concern about relying on arbitrary threshold P-values to report results as 'statistically significant'. The 'fragility index' (FI) has been proposed as an additional measure of the robustness of trial findings. FI is the minimum number of events needing to change from a non-event to an event in order to render a significant result non-significant. We calculated the FI to examine the robustness of statistically significant RCTs in CHF.

Methods and results

Two reviewers extracted data from RCTs supporting treatment recommendations in CHF guidelines. Twenty-five eligible trials were identified with a median sample size of 2331 patients (range 129-8399) and a median number of primary endpoints of 688.5 (range 88-2031). For the primary endpoint (analysed for 20 trials), the median FI was 26 (range 0-118). The FI was ≤10 in 7 (35%) of these 20 trials, and in 4 (20%) trials the number of patients lost to follow-up in the treatment group exceeded the FI.

Conclusion

The results of some large RCTs in CHF hinge on a small number of events. The FI offers an additional, easy to understand metric, which augments the standard reporting of boundary P-values for statistical significance. The FI helps in the interpretation of the robustness of the results of RCTs.

Korean Guidelines for Diagnosis and Management of Chronic Heart Failure

The prevalence of heart failure (HF) is skyrocketing worldwide, and is closely associated with serious morbidity and mortality. In particular, HF is one of the main causes for the hospitalization and mortality in elderly individuals. Korea also has these epidemiological problems, and HF is responsible for huge socioeconomic burden. However, there has been no clinical guideline for HF management in Korea. 
The present guideline provides the first set of practical guidelines for the management of HF in Korea and was developed using the guideline adaptation process while including as many data from Korean studies as possible. The scope of the present guideline includes the definition, diagnosis, and treatment of chronic HF with reduced/preserved ejection fraction of various etiologies.

Management of pulmonary hypertension from left heart disease in candidates for orthotopic heart transplantation

Pulmonary hypertension in left heart disease (PH-LHD) commonly complicates prolonged heart failure (HF). When advanced, the PH becomes fixed or out of proportion and is associated with increased morbidity and mortality in patients undergoing orthotopic heart transplant (OHT). To date, the only recommended treatment of out of proportion PH is the treatment of the underlying HF by reducing the pulmonary capillary wedge pressure (PCWP) with medications and often along with use of mechanical circulatory support. Medical therapies typically used in the treatment of World Health Organization (WHO) group 1 pulmonary arterial hypertension (PAH) have been employed off-label in the setting of PH-LHD with varying efficacy and often negative outcomes. We will discuss the current standard of care including treating HF and use of mechanical circulatory support. In addition, we will review the studies published to date assessing the efficacy and safety of PAH medications in patients with PH-LHD being considered for OHT.

Reporting of Lost to Follow-Up and Treatment Discontinuation in Pharmacotherapy and Device Trials in Chronic Heart Failure: A Systematic Review

BACKGROUND

Premature treatment discontinuation and loss to follow-up (LTFU) with unknown outcomes leave uncertainty about the true efficacy and safety of a treatment and a lack of confidence in the results of any trial. We reviewed the extent of (and trends over time in) reporting LTFU and treatment discontinuation in large studies in chronic heart failure published since 1990.

METHODS AND RESULTS

Online databases were systematically reviewed to identify randomized controlled clinical trials (RCTs) in chronic heart failure with >400 participants and utilizing all-cause mortality as a component of the primary or secondary end point. Assessments were made of documentation of treatment discontinuation, LTFU, inclusion of and completeness of a Consolidated Standards Of Reporting Trials (CONSORT) diagram, and whether LTFU was differentiated from withdrawal of consent. Sixty-eight trials were identified, with >154 000 participants. Reasons for treatment discontinuation in pharmacotherapy trials were infrequently reported (35%), particularly in a CONSORT diagram (20%). Eighty-three percent of trials reported LTFU, although only 34% of these differentiated LTFU for vital status from withdrawal of consent. Use of a CONSORT diagram increased over time, although reporting of LTFU in the CONSORT diagram remained low overall at 35%.

CONCLUSIONS

Participant flow through RCTs in chronic heart failure has not been uniformly reported, and the use of a complete CONSORT diagram has been low, although it seems to be improving. All study participants should be accounted for within a CONSORT diagram in any RCT to enable the practicing cardiologist to interpret how the results should influence his/her clinical practice.

The Role of Positive Inotropic Drugs in the Treatment of Older Adults with Heart Failure and Reduced Ejection Fraction

Positive inotropic drugs have long been studied for their potential benefits in patients with heart failure and reduced ejection fraction (HFrEF). Although there has been an extensive amount of research about the clinical effects of these drugs in general, few studies examined their effect in older patients. Therefore, there is little or no evidence to guide the use of positive inotropes in older patients with HFrEF. However, recommendations from national heart failure guidelines may be generalized to older HFrEF patients on an individual basis, taking into consideration the basic geriatric principles of pharmacotherapy: start low and go slow.

Long-Term Effects of Flosequinan on the Morbidity and Mortality of Patients With Severe Chronic Heart Failure: Primary Results of the PROFILE Trial After 24 Years

OBJECTIVES

The purpose of this clinical trial was to evaluate the long-term effects of flosequinan on the morbidity and mortality of patients with severe chronic heart failure.

BACKGROUND

Flosequinan was the first oral vasodilator to be used in the clinic to augment the effects of digitalis, diuretics, and angiotensin-converting enzyme inhibitors in heart failure. However, the drug activated neurohormonal systems and exerted both positive inotropic and chronotropic effects, raising concerns about its safety during long-term use.

METHODS

Following a run-in period designed to minimize the risk of tachycardia, we randomly assigned 2,354 patients in New York Heart Association functional class III to IV heart failure and with an ejection fraction ≤35% to receive long-term treatment with placebo or flosequinan (75 or 100 mg/day) in addition to their usual therapy. The primary outcome was all-cause mortality.

RESULTS

The trial was terminated after a recommendation of the Data and Safety Monitoring Board, because during an average of 10 months of follow-up, 192 patients died in the placebo group and 255 patients died in the flosequinan group (hazard ratio: 1.39, 95% confidence interval: 1.15 to 1.67; p = 0.0006). Flosequinan also increased the risk of disease progression, which was paralleled by drug-related increases in heart rate and neurohormonal activation. However, during the first month, patients in the flosequinan group were more likely to report an improvement in well-being and less likely to experience worsening heart failure. Similarly, during the month following drug withdrawal at the end of the trial, patients withdrawn from flosequinan were more likely than those withdrawn from placebo to report symptoms of or to require treatment for worsening heart failure.

CONCLUSIONS

Although flosequinan produced meaningful symptomatic benefits during short- and long-term treatment, the drug increased the risk of death in patients with severe chronic heart failure.

Oral Enoximone as an Alternative to Protracted Intravenous Medication in Severe Pediatric Myocardial Failure

Phosphodiesterase 3 inhibitors have been used successfully in pediatric patients with acute or chronic myocardial dysfunction over the last two decades. Their protracted continuous intravenous administration is associated with risk of infectious and thromboembolic complications. Weaning intravenous medication and starting oral angiotensin-converting enzyme (ACE) inhibitors and/or beta-blockers can be challenging. We reviewed retrospectively hospital records of 48 patients receiving oral enoximone treatment in a single tertiary pediatric cardiac center between November 2005 and April 2014. Failure to wean from intravenous milrinone infusion and/or intolerance of ACE inhibitors and/or beta-blockers was indications for oral enoximone treatment. Age of the patients ranged between 0.5 and 191 months (median 7.5 months) at the time of starting enoximone treatment. There were 14 patients (29 %) with left ventricular dysfunction due to myocarditis or dilated cardiomyopathy and 34 patients (71 %) with myocardial dysfunction complicating congenital heart disease. Fifteen (44 %) of these 34 patients had left ventricular dysfunction, 13 (38 %) right ventricular dysfunction, and in 6 (18 %) both ventricles were failing. Duration of oral enoximone treatment was between 3 days and 34 months (median of 2.3 months). Myocardial functional recovery allowed for weaning of enoximone treatment in 15 patients (31 %) after 6 days-15 months (median 5 months). No adverse hemodynamic effects were noted. Blood stained gastric aspirates encountered in two patients resolved with concomitant milk administration. Based on our limited experience, oral enoximone is a well-tolerated and promising alternative to intravenous medication and/or other commonly used oral medications in selected pediatric patients with chronic heart failure.

Quality of life and long-term mortality in patients with advanced chronic heart failure treated with intermittent low-dose intravenous inotropes in an outpatient setting

AIMS

There are limited data on the effect of low-dose, intermittent inotropic therapy in an outpatient setting on the quality of life (QOL) in patients with advanced refractory heart failure (HF) symptoms. We aimed to analyse the effect of this treatment modality on QOL and subsequent survival.

METHODS AND RESULTS

The study population comprised 287 consecutive patients with advanced refractory HF symptoms who were treated with low-dose, intravenous intermittent inotropic therapy in the HF Day Care Service at Sheba Medical Centre between September 2000 and September 2012. All patients completed a baseline Minnesota Living with Heart Failure Questionnaire (MLWHFQ), and 137 (48%) completed a 1 year follow-up questionnaire. MLWHFQ scores' means ranged from 0 (better QOL) to 5 (worse QOL). Mean age was 68 ± 12, 86% were men, 77% had ischaemic cardiomyopathy, and the mean left ventricle ejection fraction (LVEF) was 26% ± 13. The mean baseline MLWHFQ score was 3.1 (±1), while the mean at 1 year of treatment was of 2.7 (±1.1), indicating an overall improvement in QOL associated with intermittent low-dose inotrope therapy (p < 0.01). Multivariate analysis showed that younger age, non-ischaemic cardiomyopathy, and worse renal function were independently associated with improvement in QOL at 1 year. Improvement in QOL was not associated with a significant survival benefit during subsequent follow-up.

CONCLUSIONS

In patients with advanced refractory HF symptoms, treatment with low-dose, intermittent intravenous inotropes in an outpatient setting is associated with significant improvement in QOL. However, improvement in QOL in this population does not appear to affect subsequent long-term survival.