Intermittent Inotropic Infusions Combined With Prophylactic Oral Amiodarone for Patients With Decompensated End-stage Heart Failure

Intermittent levosimendan infusion in ambulatory patients with end-stage heart failure: a systematic review and meta-analysis of 984 patients

We sought to synthesize the available evidence regarding safety and efficacy of intermittent levosimendan (LEVO) infusions in ambulatory patients with end-stage heart failure (HF). Safety and efficacy of ambulatory intermittent LEVO infusion in patients with end-stage HF are yet not established. We systematically searched MEDLINE, EMBASE, SCOPUS, Web of Science, and Cochrane databases, from inception to January 30, 2021 for studies reporting outcome of adult ambulatory patients with end-stage HF treated with intermittent LEVO infusion. Fifteen studies (8 randomized and 7 observational) comprised 984 patients (LEVO [N = 727] and controls [N = 257]) met the inclusion criteria. LEVO was associated with improved New York Heart Association (NYHA) functional class (weighted mean difference [WMD] −1.04, 95%CI: −1.70 to −0.38, p < 0.001, 5 studies, I² = 93%), improved left ventricular (LV) ejection fraction (WMD 4.0%, 95%CI: 2.8% to 5.3%, p < 0.001, 6 studies, I² = 9%), and reduced BNP levels (WMD −549 pg/mL, 95%CI −866 to −233, p < 0001, 3 studies, I² = 66%). All-cause death was not different (RR 0.65, 95%CI: 0.38 to 1.093, p = 0.10, 6 studies, I² = 0), but cardiovascular death was lower on LEVO (RR 0.34, 95%CI: 0.13 to 0.87, p = 0.02, 3 studies, I² = 0) compared to controls. Furthermore, health-related quality of life (HRQoL) was improved alongside with reduced LV size following LEVO infusions. Major adverse events were not different between LEVO and placebo. In conclusion, intermittent LEVO infusions in ambulatory patients with end-stage HF is associated with less frequent cardiovascular death alongside with improved NYHA class, quality of life, BNP levels, and LV function. However, the current evidence is limited by heterogeneous and relatively small studies.

Old and New Drugs for Treatment of Advanced Heart Failure

BACKGROUND

Advanced heart failure (HF) is a progressive disease with high mortality and limited medical therapeutic options. Long-term mechanical circulatory support and heart transplantation remain goldstandard treatments for these patients; however, access to these therapies is limited by the advanced age and multiple comorbidities of affected patients, as well as by the limited number of organs available.

METHODS

Traditional and new drugs available for the treatment of advanced HF have been researched.

RESULTS

To date, the cornerstone for the treatment of patients with advanced HF remains water restriction, intravenous loop diuretic therapy and inotropic support. However, many patients with advanced HF experience loop diuretics resistance and alternative therapeutic strategies to overcome this problem have been developed, including sequential nephron blockade or use of the hypertonic saline solution in combination with high-doses of furosemide. As classic inotropes augment myocardial oxygen consumption, new promising drugs have been introduced, including levosimendan, istaroxime and omecamtiv mecarbil. However, pharmacological agents still remain mainly short-term or palliative options in patients with acute decompensation or excluded from mechanical therapy.

CONCLUSION

Traditional drugs, especially when administered in combination, and new medicaments represent important therapeutic options in advanced HF. However, their impact on prognosis remains unclear. Large trials are necessary to clarify their therapeutic potential and prognostic role in these fragile patients.

A pragmatic approach to the use of inotropes for the management of acute and advanced heart failure: An expert panel consensus

Inotropes aim at increasing cardiac output by enhancing cardiac contractility. They constitute the third pharmacological pillar in the treatment of patients with decompensated heart failure, the other two being diuretics and vasodilators. Three classes of parenterally administered inotropes are currently indicated for decompensated heart failure, (i) the beta adrenergic agonists, including dopamine and dobutamine and also the catecholamines epinephrine and norepinephrine, (ii) the phosphodiesterase III inhibitor milrinone and (iii) the calcium sensitizer levosimendan. These three families of drugs share some pharmacologic traits, but differ profoundly in many of their pleiotropic effects. Identifying the patients in need of inotropic support and selecting the proper inotrope in each case remain challenging. The present consensus, derived by a panel meeting of experts from 21 countries, aims at addressing this very issue in the setting of both acute and advanced heart failure.

Levosimendan beyond inotropy and acute heart failure: Evidence of pleiotropic effects on the heart and other organs: An expert panel position paper

Levosimendan is a positive inotrope with vasodilating properties (inodilator) indicated for decompensated heart failure (HF) patients with low cardiac output. Accumulated evidence supports several pleiotropic effects of levosimendan beyond inotropy, the heart and decompensated HF. Those effects are not readily explained by cardiac function enhancement and seem to be related to additional properties of the drug such as anti-inflammatory, anti-oxidative and anti-apoptotic ones. Mechanistic and proof-of-concept studies are still required to clarify the underlying mechanisms involved, while properly designed clinical trials are warranted to translate preclinical or early-phase clinical data into more robust clinical evidence. The present position paper, derived by a panel of 35 experts in the field of cardiology, cardiac anesthesiology, intensive care medicine, cardiac physiology, and cardiovascular pharmacology from 22 European countries, compiles the existing evidence on the pleiotropic effects of levosimendan, identifies potential novel areas of clinical application and defines the corresponding gaps in evidence and the required research efforts to address those gaps.

New pharmacologic interventions to increase cardiac contractility: challenges and opportunities

PURPOSE OF REVIEW

The most extensively studied inotropic agents in patients with heart failure are phosphodiesterase (PDE) 3 inhibitors, which increase contractility by raising intracellular cyclic adenosine monophosphate content. In clinical trials, the inotropic benefits of these agents have been outweighed by an increase in sudden cardiac death. Here, I review recent findings that help explain what are likely to be distinct mechanisms involved in the beneficial and adverse effects of PDE3 inhibition.

RECENT FINDINGS

The proapoptotic consequences of PDE3 inhibition are becoming more apparent. Moreover, it has also become clear that individual PDE3 isoforms in cardiac myocytes are selectively regulated to interact with different proteins in different intracellular compartments. The beneficial and adverse effects of PDE3 inhibition may thus be attributable to the inhibition of different isoforms in different intracellular domains. In particular, PDE3A1 has been shown to interact directly with sarcoplasmic/endoplasmic reticulum Ca ATPase (SERCA2) in the sarcoplasmic reticulum through a phosphorylation of a site in its unique N-terminal domain, making it possible that this isoform can be selectively targeted to increase intracellular Ca cycling.

SUMMARY

Conventional PDE3 inhibitors target several functionally distinct isoforms of these enzymes. Isoform-selective and/or compartment-selective targeting of PDE3, through its protein-protein interactions, may produce the inotropic benefits of PDE3 inhibition without the adverse consequences.

Inotropes do not increase mortality in advanced heart failure

Inotrope use is one of the most controversial topics in the management of heart failure. While the heart failure community utilizes them and recognizes the state of inotrope dependency, retrospective analyses and registry data have overwhelmingly suggested high mortality, which is logically to be expected given the advanced disease states of those requiring their use. Currently, there is a relative paucity of randomized control trials due to the ethical dilemma of creating control groups by withholding inotropes from patients who require them. Nonetheless, results of such trials have been mixed. Many were also performed with agents no longer in use, on patients without an indication for inotropes, or at a time before automatic cardio-defibrillators were recommended for primary prevention. Thus, their results may not be generalizable to current clinical practice. In this review, we discuss current indications for inotrope use, specifically dobutamine and milrinone, depicting their mechanisms of action, delineating their patterns of use in clinical practice, defining the state of inotrope dependency, and ultimately examining the literature to ascertain whether evidence is sufficient to support the current view that these agents increase mortality in patients with heart failure. Our conclusion is that the evidence is insufficient to link inotropes and increased mortality in low output heart failure.

PDE3 inhibition in dilated cardiomyopathy

In dilated cardiomyopathy, a condition characterized by chamber enlargement and reduced myocardial contractility, decreases in β-adrenergic receptor density and increases in Gαi and β-adrenergic receptor kinase activities attenuate the stimulation of adenylyl cyclase in response to catecholamines. PDE3 inhibitors have been used to 'overcome' the reduction in cAMP generation by blocking cAMP hydrolysis. These drugs increase contractility in the short-term, but long-term administration leads to an increase in mortality that correlates with an increase in sudden cardiac death. Whether separate mechanisms account for these beneficial and harmful effects, and, if so, whether PDE3 can be targeted so as to increase contractility without increasing mortality are questions that remain unanswered.

The challenge of treating congestion in advanced heart failure

Volume overload is a common manifestation of heart failure decompensation. Interaction between impaired renal and heart function constitutes an important pathophysiologic mechanism that leads to congestion. In addition to improving symptoms and volume status, reduction of rehospitalization rates, maintenance of renal function and improvement of survival are all important goals of every therapeutic strategy. Currently, the use of diuretics, vasodilators, inotropes and ultrafiltration, together with investigational agents such as oral vasopressin antagonists and adenosine A1-receptor antagonists, constitute the main therapeutic options for the congested heart failure patient.

Phosphodiesterase inhibition in heart failure

Compounds that inhibit the catalytic activity of cyclic nucleotide phosphodiesterases are used as therapeutic agents to increase intracellular cAMP and/or cGMP content in cells or tissues of interest. In patients with heart failure, inhibitors of enzymes in the PDE3 family of cyclic nucleotide phosphodiesterases are used to raise intracellular cAMP content in cardiac muscle, with inotropic actions. These drugs are effective in acute applications, but their long-term use has been complicated by an increase in cardiovascular mortality in clinical trials. Inhibitors of enzymes in the PDE5 family have been used to raise cGMP content in cardiac muscle in animal models of pressure overload, chronic β-adrenergic receptor stimulation, ischemic injury, and doxorubicin toxicity, and have been shown to have antihypertrophic and cardioprotective actions. Recent experimental results raise some question as to the likely applicability of these findings to humans, in whose hearts PDE5 is present at much lower levels than those seen in animal models, and raise the possibility of PDE1, a dual-specificity phosphodiesterase present at high levels in human myocardium, as an alternative target for inotropic and cardioprotective actions.

The future is here: ventricular assist devices for the failing heart

Mechanical circulatory support is an important adjunct to the management of patients with advanced heart failure. Technological advances in this area have improved overall survival and decreased the incidence of complications. In addition, they have expanded the population suitable for this therapy. The challenge for clinicians is to translate the clinical evidence into the selection of the most appropriate device that will benefit an individual patient. This paper will review ventricular assist devices currently available and their clinical indications.