Heart failure etiology and response to milrinone in decompensated heart failure: results from the OPTIME-CHF study

Outcomes and Care of Patients With Acute Heart Failure Syndromes and Cardiac Troponin Elevation

Background—

Cardiac troponins (cTn) may be elevated among patients with acute heart failure syndromes (AHFS). However, the optimal approach to management of AHFS with elevated cTn is unknown.

Methods and Results—

We compared the care and outcomes of 13 656 patients with AHFS seeking care in the emergency department stratified by presence (cTn+, n=1845, 13.5%) or absence (cTn−) of elevated troponin. Clinically abstracted data on patients who were admitted or discharged from the emergency department in Ontario, Canada (April 1999 to March 2001 and April 2004 to March 2007) were examined. In an exploratory 2:1 propensity-matched analysis, we examined whether early coronary revascularization (within 14 days of emergency department visit) was associated with survival, stratified by cTn status. For cTn+ AHFS, rates of coronary angiography (21.8 vs 11.4 patients/100 person-years; P <0.001) and coronary revascularization (8.8 vs 3.2 patients/100 person-years; P <0.001) were higher than cTn−. Instantaneous 30-day adjusted hazard ratios for cTn+ versus cTn− patients were 9.17 (95% confidence interval [CI], 8.31–10.12; P <0.001) for death, 5.14 (95% CI, 4.66–5.67; P <0.001) for cardiovascular readmission, and 13.08 (95% CI, 10.95–15.62; P <0.001) for ischemic heart disease hospitalization. In propensity-matched analysis of 143 individuals with cTn+ AHFS, early coronary revascularization was associated with reduced mortality (adjusted hazard ratio, 0.29; 95% CI, 0.09–0.92; P =0.036) compared with those who were not revascularized. Mortality was not significantly reduced among 210 cTn− patients undergoing early coronary revascularization (adjusted hazard ratio, 0.61; 95% CI, 0.36–1.03; P =0.065).

Conclusions—

Elevated cTn was associated with increased risk of death and cardiovascular hospitalizations. Highly selected cTn+ patients who underwent early coronary revascularization for obstructive coronary artery disease experienced improved survival.

Serelaxin, recombinant human relaxin-2, for treatment of acute heart failure (RELAX-AHF): a randomised, placebo-controlled trial

BACKGROUND

Serelaxin, recombinant human relaxin-2, is a vasoactive peptide hormone with many biological and haemodynamic effects. In a pilot study, serelaxin was safe and well tolerated with positive clinical outcome signals in patients with acute heart failure. The RELAX-AHF trial tested the hypothesis that serelaxin-treated patients would have greater dyspnoea relief compared with patients treated with standard care and placebo.

METHODS

RELAX-AHF was an international, double-blind, placebo-controlled trial, enrolling patients admitted to hospital for acute heart failure who were randomly assigned (1:1) via a central randomisation scheme blocked by study centre to standard care plus 48-h intravenous infusions of placebo or serelaxin (30 μg/kg per day) within 16 h from presentation. All patients had dyspnoea, congestion on chest radiograph, increased brain natriuretic peptide (BNP) or N-terminal prohormone of BNP, mild-to-moderate renal insufficiency, and systolic blood pressure greater than 125 mm Hg. Patients, personnel administering study drug, and those undertaking study-related assessments were masked to treatment assignment. The primary endpoints evaluating dyspnoea improvement were change from baseline in the visual analogue scale area under the curve (VAS AUC) to day 5 and the proportion of patients with moderate or marked dyspnoea improvement measured by Likert scale during the first 24 h, both analysed by intention to treat. This trial is registered at ClinicalTrials.gov, NCT00520806.

FINDINGS

1161 patients were randomly assigned to serelaxin (n=581) or placebo (n=580). Serelaxin improved the VAS AUC primary dyspnoea endpoint (448 mm × h, 95% CI 120-775; p=0·007) compared with placebo, but had no significant effect on the other primary endpoint (Likert scale; placebo, 150 patients [26%]; serelaxin, 156 [27%]; p=0·70). No significant effects were recorded for the secondary endpoints of cardiovascular death or readmission to hospital for heart failure or renal failure (placebo, 75 events [60-day Kaplan-Meier estimate, 13·0%]; serelaxin, 76 events [13·2%]; hazard ratio [HR] 1·02 [0·74-1·41], p=0·89] or days alive out of the hospital up to day 60 (placebo, 47·7 [SD 12·1] days; serelaxin, 48·3 [11·6]; p=0·37). Serelaxin treatment was associated with significant reductions of other prespecified additional endpoints, including fewer deaths at day 180 (placebo, 65 deaths; serelaxin, 42; HR 0·63, 95% CI 0·42-0·93; p=0·019).

INTERPRETATION

Treatment of acute heart failure with serelaxin was associated with dyspnoea relief and improvement in other clinical outcomes, but had no effect on readmission to hospital. Serelaxin treatment was well tolerated and safe, supported by the reduced 180-day mortality.

FUNDING

Corthera, a Novartis affiliate company.

Cardiac sodium-calcium exchange and efficient excitation-contraction coupling: implications for heart disease

Cardiovascular disease is a leading cause of death worldwide, with ischemic heart disease alone accounting for >12% of all deaths, more than HIV/AIDS, tuberculosis, lung, and breast cancer combined. Heart disease has been the leading cause of death in the United States for the past 85 years and is a major cause of disability and health-care expenditures. The cardiac conditions most likely to result in death include heart failure and arrhythmias, both a consequence of ischemic coronary disease and myocardial infarction, though chronic hypertension and valvular diseases are also important causes of heart failure. Sodium-calcium exchange (NCX) is the dominant calcium (Ca2+) efflux mechanism in cardiac cells. Using ventricular-specific NCX knockout mice, we have found that NCX is also an essential regulator of cardiac contractility independent of sarcoplasmic reticulum Ca2+ load. During the upstroke of the action potential, sodium (Na+) ions enter the diadic cleft space between the sarcolemma and the sarcoplasmic reticulum. The rise in cleft Na+, in conjunction with depolarization, causes NCX to transiently reverse. Ca2+ entry by this mechanism then "primes" the diadic cleft so that subsequent Ca2+ entry through Ca2+ channels can more efficiently trigger Ca2+ release from the sarcoplasmic reticulum. In NCX knockout mice, this mechanism is inoperative (Na+ current has no effect on the Ca2+ transient), and excitation-contraction coupling relies upon the elevated diadic cleft Ca2+ that arises from the slow extrusion of cytoplasmic Ca2+ by the ATP-dependent sarcolemmal Ca2+ pump. Thus, our data support the conclusion that NCX is an important regulator of cardiac contractility. These findings suggest that manipulation of NCX may be beneficial in the treatment of heart failure.

The 2012 Canadian Cardiovascular Society heart failure management guidelines update: focus on acute and chronic heart failure

The 2012 Canadian Cardiovascular Society Heart Failure (HF) Guidelines Update provides management recommendations for acute and chronic HF. In 2006, the Canadian Cardiovascular Society HF Guidelines committee first published an overview of HF management. Since then, significant additions to and changes in many of these recommendations have become apparent. With this in mind and in response to stakeholder feedback, the Guidelines Committee in 2012 has updated the overview of both acute and chronic heart failure diagnosis and management. The 2012 Update also includes recommendations, values and preferences, and practical tips to assist the medical practitioner manage their patients with HF.

Pathophysiological relevance of the cardiac β2-adrenergic receptor and its potential as a therapeutic target to improve cardiac function

β-adrenoceptors are members of the G protein-coupled receptor superfamily which play a key role in the regulation of myocardial function. Their activation increases cardiac performance but can also induce deleterious effects such as cardiac arrhythmias or myocardial apoptosis. In fact, inhibition of β-adrenoceptors exerts a protective effect in patients with sympathetic over-stimulation during heart failure. Although β(2)-adrenoceptor is not the predominant subtype in the heart, it seems to importantly contribute to the cardiac effects of adrenergic stimulation; however, the mechanism by which this occurs is not fully understood. This review summarizes the current knowledge on the role of β(2)-adrenoceptors in the regulation of cardiac contractility, metabolism, cardiomyocyte survival and cardiac arrhythmias. In addition, therapeutic considerations relating to stimulation of the β(2)-adrenoceptor such as an increase in cardiac contractility with low arrythmogenic effect, protection of the myocardium again apoptosis or positive regulation of heart metabolism are discussed.

Inotropes for the management of acute heart failure patients with renal dysfunction. Still an option?

INTRODUCTION

Renal dysfunction is highly prevalent in patients with acute heart failure (AHF). These patients are more vulnerable in worsening of kidney function and have also higher mortality rates.

AREAS COVERED

Recent developments in the understanding of bidirectional interaction between heart and kidney are reviewed in the context of the potential impact of inotropes on renal function. Key clinical trials reporting the use of inotropes in AHF patients with renal dysfunction are discussed in this review.

EXPERT OPINION

Inotropes may be indicated on a short-term basis and under close monitoring in AHF with renal dysfunction mostly in cases of low output heart failure that can provoke renal hypoperfusion. Dopamine administration with low dose of i.v. furosemide has been recently compared with high dose of i.v. furosemide alone, demonstrating lower rates of worsening renal function and electrolyte disturbances. Moreover, small clinical trials have shown that the novel inodilator levosimendan seems to be superior to dobutamine or placebo in improving renal function in patients with acutely decompensated heart failure. The impact of novel inotropes on kidney function is still unclear. Randomized clinical trials are required in order to identify the role of inotropes in the management and/or prevention of acute cardiorenal syndrome.

Novel therapies in acute and chronic heart failure

Despite past advances in the pharmacological management of heart failure, the prognosis of these patients remains poor, and for many, treatment options remain unsatisfactory. Additionally, the treatments and clinical outcomes of patients with acute decompensated heart failure have not changed substantially over the past few decades. Consequently, there is a critical need for new drugs that can improve clinical outcomes. In the setting of acute heart failure, new inotrops such as cardiac myosin activators and new vasodilators such as relaxin have been developed. For chronic heart failure with reduced ejection fraction, there are several new approaches that target multiple pathophysiological mechanism including novel blockers of the renin-angiotensin-aldosterone system (direct renin inhibitors, dual-acting inhibitors of the angiotensin II receptor and neprilysin, aldosterone synthase inhibitors), ryanodine receptor stabilizers, and SERCA activators. Heart failure with preserved ejection fraction represents a substantial therapeutic problem as no therapy has been demonstrated to improve symptoms or outcomes in this condition. Newer treatment strategies target specific structural and functional abnormalities that lead to increased myocardial stiffness. Dicarbonyl-breaking compounds reverse advanced glycation-induced cross-linking of collagen and improve the compliance of aged and/or diabetic myocardium. Modulation of titin-dependent passive tension can be achieved via phosphorylation of a unique sequence on the extensible region of the protein. This review describes the pathophysiological basis, mechanism of action, and available clinical efficacy data of drugs that are currently under development. Finally, new therapies for the treatment of heart failure complications, such as pulmonary hypertension and anemia, are discussed.

Acute decompensated heart failure - treatments and challenges -

Acute decompensated heart failure (ADHF) is a major public health problem throughout the world and its importance is continuing to grow. This article reviews the epidemiology of ADHF and the profile of patients suffering from this condition. It describes factors used in assessing prognosis and presents treatment options. Although no currently available treatments have been shown to favorably affect long-term outcomes, there are a variety of strategies and approaches to management that are expected to reduce morbidity and mortality following discharge after ADHF hospitalization. In particular, the clinician is alerted to the need to identify factors that trigger decompensation as well as to optimize treatments for chronic heart failure. The importance of the transition from hospital to the outpatient setting is described. Particular attention should be focused on providing health education to the patient and their family at an appropriate level of medical literacy as well as ensuring early follow-up evaluation after hospital discharge.

Positive inotropes in heart failure: a review article

Increasing myocardial contractility has long been considered a big help for patients with systolic heart failure, conferring an augmented haemodynamic profile in terms of higher cardiac output, lower cardiac filling pressure and better organ perfusion. Though concerns have been raised over the safety issues regarding the clinical trials of different inotropes in hearts with systolic dysfunction, they still stand as a main therapeutic strategy in many centres dealing with such patients. They must be used as short in duration, low in dose and stopped as early as possible. Evidence-based guidelines have provided clinicians with valuable data for better applying inotropes in heart failure patients. In this paper, the authors address clinical trials with different agents used for increasing cardiac contractility in heart failure patients. Furthermore, the authors focus on recent guidelines on making the most out of inotropes in heart failure patients.

Heart failure and non-ST-segment elevation myocardial infarction: a review for a widespread situation

Up to 15% of patients with NSTEMI present at admission with heart failure. Scientific evidence for its management is limited but much progress has been made during the last years. Our purpose was to review the last data concerning heart failure in NSTEMI and perform an update on the subject, with the following findings as main highlights. As Killip classes III and IV, Killip class II onset in the context of NSTEMI has also proven bad prognosis significance. Beta-blocker therapy has proven benefit to patients with Killip class II in observational studies and small trials. Angiotensin-converting enzyme inhibitor therapy shows stronger evidence of benefit in patients with heart failure than in patients without it. Eplerenone is indicated for patients with left ventricular dysfunction and heart failure or diabetes mellitus. Implantable cardioverter defibrillators improve survival in patients with severe ventricular dysfunction after a myocardial infarction. Cardiac resynchronization therapy indications must be carefully assessed due to the high rate of implants that do not fulfill guidelines indications. In conclusion, heart failure during a NSTEMI is a common and meaningful situation which warrants careful management and further investigation to reach stronger evidence for clinical recommendations.

Old and new intravenous inotropic agents in the treatment of advanced heart failure

Inotropic agents are administered to improve cardiac output and peripheral perfusion in patients with systolic dysfunction and low cardiac output. However, there is evidence of increased mortality and adverse effects associated with current inotropic agents. These adverse outcomes may be ascribed to patient selection, increased myocardial energy expenditure and oxygen consumption, or to specific mechanisms of action. Both sympathomimetic amines and type III phosphodiesterase inhibitors act through an increase in intracellular cyclic adenosine monophoshate and free calcium concentrations, mechanisms that increase oxygen consumption and favor arrhythmias. Concomitant peripheral vasodilation with some agents (phosphodiesterase inhibitors and levosimendan) may also lower coronary perfusion pressure and favor myocardial damage. New agents with different mechanisms of action might have a better benefit to risk ratio and allow an improvement in tissue and end-organ perfusion with less untoward effects. We have summarized the characteristics of the main inotropic agents for heart failure treatment, the data from randomized controlled trials, and future perspectives for this class of drugs.

Anesthetic considerations for the patient undergoing therapy for advanced heart failure

PURPOSE OF REVIEW

Advanced heart failure (AHF) affects a growing percentage of our population. The anesthesiologist must be cognizant of the perioperative considerations of patients undergoing state-of-the-art therapy for AHF. These therapies include classic and novel agents to improve systolic function, neurohormonal modulators, heart rhythm and synchronization management and mechanical support of the circulation. The perioperative considerations and recommendations may range from invasive hemodynamic monitoring, management of proper inotropic support to maintain left ventricular and right ventricular systolic function, isolation from electromagnetic interference in patients with rhythm management devices, maintenance of appropriate systemic and pulmonary vascular resistance, and surgical planning and anticoagulant management.

RECENT FINDINGS

Studies of the efficacy and hemodynamic changes of patients on inotropic therapy (milrinone, levosimendan, and istaroxime) and neuropeptide (nesiritide) therapy will be reviewed. Perioperative considerations of patients on mechanical circulatory support will be discussed. The need for implementation of temporary mechanical support for noncardiac surgery will be discussed.

SUMMARY

A working knowledge of AHF treatments and perioperative considerations is necessary for all anesthesiologists as more patients receiving therapy will be presenting for all types of surgical procedures.

Dose-dependent augmentation of cardiac systolic function with the selective cardiac myosin activator, omecamtiv mecarbil: a first-in-man study

BACKGROUND

Decreased systolic function is central to the pathogenesis of heart failure in millions of patients worldwide, but mechanism-related adverse effects restrict existing inotropic treatments. This study tested the hypothesis that omecamtiv mecarbil, a selective cardiac myosin activator, will augment cardiac function in human beings.

METHODS

In this dose-escalating, crossover study, 34 healthy men received a 6-h double-blind intravenous infusion of omecamtiv mecarbil or placebo once a week for 4 weeks. Each sequence consisted of three ascending omecamtiv mecarbil doses (ranging from 0·005 to 1·0 mg/kg per h) with a placebo infusion randomised into the sequence. Vital signs, blood samples, electrocardiographs (ECGs), and echocardiograms were obtained before, during, and after each infusion. The primary aim was to establish maximum tolerated dose (the highest infusion rate tolerated by at least eight participants) and plasma concentrations of omecamtiv mecarbil; secondary aims were evaluation of pharmacodynamic and pharmacokinetic characteristics, safety, and tolerability. This study is registered at ClinicalTrials.gov, number NCT01380223.

FINDINGS

The maximum tolerated dose of omecamtiv mecarbil was 0·5 mg/kg per h. Omecamtiv mecarbil infusion resulted in dose-related and concentration-related increases in systolic ejection time (mean increase from baseline at maximum tolerated dose, 85 [SD 5] ms), the most sensitive indicator of drug effect (r(2)=0·99 by dose), associated with increases in stroke volume (15 [2] mL), fractional shortening (8% [1]), and ejection fraction (7% [1]; all p<0·0001). Omecamtiv mecarbil increased atrial contractile function, and there were no clinically relevant changes in diastolic function. There were no clinically significant dose-related adverse effects on vital signs, serum chemistries, ECGs, or adverse events up to a dose of 0·625 mg/kg per h. The dose-limiting toxic effect was myocardial ischaemia due to excessive prolongation of systolic ejection time.

INTERPRETATION

These first-in-man data show highly dose-dependent augmentation of left ventricular systolic function in response to omecamtiv mecarbil and support potential clinical use of the drug in patients with heart failure.

FUNDING

Cytokinetics Inc.

Pharmaceutical management of decompensated heart failure syndrome in children: current state of the art and a new approach

Prompt initiation of appropriate and intensive treatment in children with decompensated heart failure is crucial to avoid irreversible end-organ dysfunction. Initial management of these children includes transfer to the pediatric cardiac intensive care unit, basic hemodynamic monitoring, and establishment of intravenous access. Inotropic support should be instituted peripherally before obtaining central venous and arterial access. The team should be prepared for emergent intubation and initiation of mechanical circulatory support. Two experienced physicians should work together to obtain vascular access and manage sedation, airway control, and cardiovascular support. Acute heart failure syndrome in children may be related to cardiomyopathy, myocarditis, congenital heart disease, and acute rejection post heart transplantation. Each of these causes requires a different approach. Fulminant myocarditis may lead to severe morbidity and requires intensive support, although its outcome is considered to be good. Acute heart failure related to newly diagnosed dilated cardiomyopathy may represent end-stage heart failure; therefore, long-term mechanical circulatory support and heart transplantation may be considered to avoid other end-organ dysfunction. Hypertrophic cardiomyopathy may lead to acute decompensation due to 1) left ventricular outflow obstruction, 2) restrictive physiology leading to pulmonary hypertension, or 3) myocardial ischemia associated with coronary artery bridging. Decompensated heart failure associated with congenital heart disease usually represents end-stage heart failure and requires thorough evaluation for heart transplantation. Children with single-ventricle physiology who develop decompensated heart failure after a Fontan procedure are not candidates for mechanical circulatory support and therefore may not survive to heart transplantation. Acute heart failure due to posttransplantation acute rejection requires aggressive antirejection treatment, which places these patients at significant risk for overwhelming opportunistic infections. In our opinion, mechanical circulatory support should be initiated early in children who present with end-stage heart failure associated with hemodynamic instability to avoid end-organ damage.

Use of inotropic agents in patients with advanced heart failure: lessons from recent trials and hopes for new agents

Abnormalities of cardiac function, with high intraventricular filling pressure and low cardiac output, play a central role in patients with heart failure. Agents with inotropic properties are potentially useful to correct these abnormalities. However, with the exception of digoxin, no inotropic agent has been associated with favourable effects on outcomes. This is likely related to the mechanism of action of current agents, which is based on an increase in intracellular cyclic adenosine monophosphate and calcium concentrations. Novel agents acting through different mechanisms, such as sarcoplasmic reticulum calcium uptake, cardiac myosin and myocardial metabolism, have the potential to improve myocardial efficiency and lower myocardial oxygen consumption. These characteristics might allow a haemodynamic improvement in the absence of untoward effects on the clinical course and prognosis of the patients.

Cardiac resynchronization therapy for critically ill patients with left ventricular systolic dysfunction

BACKGROUND

The experience of cardiac resynchronization therapy (CRT) in critically ill patients with cardiogenic shock or advanced heart failure is limited and inadequately described in literature.

METHODS

CRT implants performed in patients on the cardiothoracic intensive care unit (ICU) at a tertiary cardiac centre during 2007-2010 were retrospectively studied.

RESULTS

We identified 24 patients, 17 male, of median age 76 years (IQR 11) treated with a CRT pacemaker (n=10) or CRT defibrillator (n=14). Prior to implantation median left ventricular ejection fraction (LVEF) was 26% (IQR 13) and median QRS duration 146 ms (IQR 29). Eleven (46%) patients were post elective cardiac surgery and 8 (33%) post emergency cardiac surgery or intervention with high prevalence of co-morbidities. Nineteen patients required inotropic support pre-implantation, 8 patients were on mechanical circulatory support and 18 were on mechanical ventilation. Post CRT LVEF improved from 26% to 39% (p=0.027) and the estimated glomerular filtration rate increased from 42 ml/min/1.73 m(2) (IQR 26) to 63 ml/min/1.73 m(2) (IQR 48, p=0.001). All but one patient were successfully weaned from inotropic support within a median of 4 days (IQR 5) post CRT and 22/24 (92%) survived to hospital discharge. After a median follow up of 392 days (IQR 538), 7 (33%) patients died. In-hospital and one year mortality rates were 8.3% and 29.4% respectively. Ten out of 12 patients (83%) were alive at long-term (22 ± 9 months) follow up.

CONCLUSIONS

CRT may assist weaning from circulatory and respiratory support in critically ill patients with left ventricular systolic dysfunction.

Modulation of beta-adrenergic receptor signaling in heart failure and longevity: targeting adenylyl cyclase type 5

Despite remarkable advances in therapy, heart failure remains a leading cause of morbidity and mortality. Although enhanced beta-adrenergic receptor stimulation is part of normal physiologic adaptation to either the increase in physiologic demand or decrease in cardiac function, chronic beta-adrenergic stimulation has been associated with increased mortality and morbidity in both animal models and humans. For example, overexpression of cardiac Gsalpha or beta-adrenergic receptors in transgenic mice results in enhanced cardiac function in young animals, but with prolonged overstimulation of this pathway, cardiomyopathy develops in these mice as they age. Similarly, chronic sympathomimetic amine therapy increases morbidity and mortality in patients with heart failure. Conversely, the use of beta-blockade has proven to be of benefit and is currently part of the standard of care for heart failure. It is conceivable that interrupting distal mechanisms in the beta-adrenergic receptor-G protein-adenylyl cyclase pathway may also provide targets for future therapeutic modalities for heart failure. Interestingly, there are two major isoforms of adenylyl cyclase (AC) in the heart (type 5 and type 6), which may exert opposite effects on the heart, i.e., cardiac overexpression of AC6 appears to be protective, whereas disruption of type 5 AC prolongs longevity and protects against cardiac stress. The goal of this review is to summarize the paradigm shift in the treatment of heart failure over the past 50 years from administering sympathomimetic amine agonists to administering beta-adrenergic receptor antagonists, and to explore the basis for a novel therapy of inhibiting type 5 AC.

Narrative review: the management of acute decompensated heart failure

Acute decompensated heart failure (ADHF) is the most common reason for hospitalization in Western nations. The prognosis of patients admitted to hospital with ADHF is poor, with up to 64% being readmitted within the first 90 days after discharge and with a 1-year mortality approximating 20%. Epidemiological studies suggest that the majority of patients hospitalized with ADHF receive treatment that is inadequate and which is not based on scientific evidence. Furthermore, emerging data suggest that the "conventional" therapeutic interventions for ADHF including morphine, high-dose diuretics, and inotropic agents may be harmful. The goal of this review is to provide evidence-based recommendations for the diagnosis and management of ADHF.

Differential regulation of β2 -adrenoceptor-mediated inotropic and lusitropic response by PDE3 and PDE4 in failing and non-failing rat cardiac ventricle

BACKGROUND AND PURPOSE

β-Adrenoceptors play a major role in regulating myocardial function through cAMP-dependent pathways. Different phosphodiesterases (PDEs) regulate intracellular cAMP-pools and thereby contribute to the compartmentalization of cAMP-dependent effects. We explored the involvement of PDEs in limiting the β(2) adrenoceptor-mediated positive inotropic (PIR) and lusitropic (LR) responses in sham-operated (Sham) and failing rat hearts.

EXPERIMENTAL APPROACH

Extensive myocardial infarctions were induced by coronary artery ligation in Wistar rats. Rats developing heart failure were studied 6 weeks after surgery. Contractility was measured in left ventricular strips from failing and Sham hearts. cAMP was quantified by RIA.

KEY RESULTS

In ventricular strips, stimulation of β(2) -adrenoceptors with (-)-adrenaline (300 nM CGP20712A present) exerted a small PIR and LR. In Sham hearts, β(2) -adrenoceptor-mediated as well as β(1) -adrenoceptor-mediated PIR and LR were increased by selective inhibition of either PDE3 (1 µM cilostamide) or PDE4 (10 µM rolipram). In failing rat hearts, PDE3 inhibition enhanced PIR and LR to both β(1) - and β(2) -adrenoceptor stimulation while PDE4 inhibition had no effect on these responses despite a significant increase in cAMP levels. Combined PDE3/4 inhibition further enhanced the PIR and LR of β(2) - and β(1) -adrenoceptor activation both in Sham and failing hearts, compared with PDE3 inhibition alone. PDE4 enzyme activity was reduced in failing hearts.

CONCLUSIONS AND IMPLICATIONS

Both PDE3 and PDE4 attenuated β(2) - and β(1) -adrenoceptor-mediated contractile responses in Sham hearts. In failing hearts, these responses are attenuated solely by PDE3 and thus even selective PDE3 inhibitors may provide a profound enhancement of β-adrenoceptor-mediated responses in heart failure.

Heart failure treatment in the intensive care unit in children

Although pediatric heart failure is generally a chronic, progressive disorder, recovery of ventricular function may occur with some forms of cardiomyopathy. Guidelines for the management of chronic heart failure in adults and children have recently been published by the International Society for Heart and Lung Transplantation the American College of Cardiology, and the American Heart Association. The primary aim of heart failure therapy is to reduce symptoms, preserve long-term ventricular performance, and prolong survival primarily through antagonism of the neurohormonal compensatory mechanisms. Because some medications may be detrimental during an acute decompensation, physicians who manage these patients as inpatients must be knowledgeable about the medications and therapeutic goals of chronic heart failure treatment. Understanding the mechanisms of chronic heart failure may foster improved understanding of the treatment of decompensated heart failure.

Levosimendan in the Treatment of Acute Heart Failure, Cardiogenic and Septic Shock: A Critical Review

Levosimendan is a drug which increases the sensitivity of the heart to calcium and which opens potassium channels, resulting in inodilation. Clinical trial data from patients suffering from heart failure have demonstrated that it improves haemodynamics without increasing intra-cellular calcium or oxygen consumption. However, there is no consistent evidence of mortality reduction. This narrative review summarises the key trials of its use in acute heart failure, acute coronary syndrome, cardiogenic shock and septic shock.

Acute heart failure with low cardiac output: can we develop a short-term inotropic agent that does not increase adverse events?

Acute heart failure represents an increasingly common cause of hospitalization, and may require the use of inotropic drugs in patients with low cardiac output and evidence of organ hypoperfusion. However, currently available therapies may have deleterious effects and increase mortality. An ideal inotropic drug should restore effective tissue perfusion by enhancing myocardial contractility without causing adverse effects. Such a drug is not available yet. New agents with different biological targets are under clinical development. In particular, istaroxime seems to dissociate the inotropic effect exerted by digitalis (inhibition of the membrane sodium/potassium adenosine triphosphatase) from the arrhythmic effect and to ameliorate diastolic dysfunction (via sarcoendoplasmic reticulum calcium adenosine triphosphatase activation). Additionally, the myosin activator omecamtiv mecarbil appears to have promising characteristics, while genetic therapy has been explored in animal studies only. Further investigations are needed to confirm and expand the effectiveness and safety of these agents in patients with acute heart failure and low cardiac output.

Troponin elevation in heart failure prevalence, mechanisms, and clinical implications

Circulating biomarkers have become increasingly important in diagnosing and risk stratifying patients with heart failure (HF). While the natriuretic peptides have received much focus, there is increasing interest in the role of circulating cardiac troponin (cTn) in detecting myocardial injury (often subclinical) in those with HF. Accumulating evidence suggests that patients with chronic and acute HF may have measurable levels of circulating cTn, whose detection and magnitude may have prognostic implications. Furthermore, as new, more sensitive cTn assays are being developed, larger numbers of HF patients are found to have detectable cTn with a persistent relationship between magnitude and outcome. This knowledge improves our ability to understand the mechanism of worsening HF, improve risk stratification, and detect potential injury related to new therapeutics in HF. As investigators begin to understand the relationship of detectable cTn to HF outcomes, as well as temporal changes in its magnitude, and its relationship to other circulating biomarkers, more insight may be gained into the progressive nature of cardiac dysfunction and the transition from chronic compensated to acute decompensated HF. Ultimately, this information might allow physicians to guide therapy, choose appropriate therapeutics, and improve HF outcomes.

The cardiorenal syndrome: making the connection

The heart and the kidneys share responsibility for maintaining hemodynamic stability and end-organ perfusion. Connections between these organs ensure that subtle physiologic changes in one system are tempered by compensation in the other through a variety of pathways and mediators. In the setting of underlying heart disease or chronic kidney disease, the capacity of each organ to respond to perturbation caused by the other may become compromised. This has recently led to the characterization of the cardiorenal syndrome (CRS). This review will primarily focus on CRS type 1 where acute decompensated heart failure (ADHF) results in activation of hemodynamic and neurohormonal factors leading to an acute drop in the glomerular filtration rate and the development of acute kidney injury. We will examine the scope and impact of this problem, the pathophysiology associated with this relationship, including underperfuson and venous congestion, diagnostic tools for earlier detection, and therapeutic interventions to prevent and treat this complication.

Managing hyponatremia in patients with heart failure

Approximately 20% of heart failure patients have low levels of serum sodium, often at a time when they are hospitalized during a period of decompensation. The presence of hyponatremia adversely affects outcomes in heart failure and is associated with impaired cognitive and neuromuscular function. Current strategies for treating hyponatremia in heart failure patients have limited efficacy. Although the development of hyponatremia in heart failure patients is polyfactorial, the nonosmotic release of arginine vasopressin (AVP) from the posterior pituitary plays a dominant role in this process through its effects on regulating the absorption of free water in the distal portion of the nephron. Drugs which block the effects of AVP on the V2 receptor have been shown to increase serum sodium by promoting the excretion of free water from the kidney. In this review, the theoretical basis supporting the use of AVP blockers is discussed and results from clinical trials in which they were administered to euvolemic and hypervolemic patients are reviewed. Administration of AVP blockers to heart failure patients increases free water excretion, promotes weight loss, and increases serum sodium levels without significant major adverse effects. Clinical trial results demonstrate safety during long-term administration. These findings indicate that the use of AVP receptor antagonists should be considered in heart failure patients who have evidence of significant hyponatremia.

Update on inotropic therapy in the management of acute heart failure

The use of classic inotropic agents activating the beta-receptor-cyclic adenosine monophosphate (cAMP) pathway (ie, dobutamine or milrinone) should be restricted to a "rescue" therapy in patients with acute heart failure and signs of peripheral hypoperfusion (hypotension, renal dysfunction) that is refractory to volume replacement, diuretics, and vasodilators. This approach is largely supported by observations from clinical trials suggesting that both short-term treatment of acute heart failure without an essential requirement of inotropic support as well as long-term inotropic therapy in patients with severe chronic heart failure with classical inotropic agents can increase arrhythmia and mortality. Vice versa, beta-receptor blockade, whenever tolerated, improves survival in patients with severe stable heart failure, further supporting the concept that beta-receptor stimulation has adverse long-term effects. Positive inotropic therapy stimulating the beta-receptor-cAMP pathway should, therefore, be used with caution, given the potential harmful effects. Levosimendan, a novel calcium sensitizer, has recently attracted substantial clinical interest and may be superior to classical inotropes with respect to improving cardiac mechanical efficiency and avoiding adverse effects such as increasing myocardial oxygen uptake or cardiomyocyte death. Earlier clinical studies have suggested a beneficial effect on survival compared with dobutamine or placebo in patients with acute heart failure (LIDO , RUSSLAN , and CASINO trials). However, more recent data from two large clinical trials (SURVIVE and REVIVE trials) did not confirm these beneficial effects on mortality. Therefore, additional data are required with respect to the optimum dosing of levosimendan and patient selection to reach a definitive conclusion about the role of levosimendan in the management of patients with acute heart failure.

Therapeutic strategies for heart failure in cardiorenal syndromes

Cardiorenal syndromes are disorders of the heart and kidneys whereby acute or long-term dysfunction in one organ may induce acute or long-term dysfunction of the other. The management of cardiovascular diseases and risk factors may influence, in a beneficial or harmful way, kidney function and progression of kidney injury. In this review, we assess therapeutic strategies and discuss treatment options for the management of patients with heart failure with decreased kidney function and highlight the need for future high-quality studies in patients with coexisting heart and kidney disease.

Acute heart failure: multiple clinical profiles and mechanisms require tailored therapy

Acute heart failure (HF) is the most common diagnosis at discharge in patients aged >65years. It carries a dismal prognosis with a high in-hospital mortality and very high post-discharge mortality and re-hospitalization rates. It is a complex clinical syndrome that cannot be described as a single entity as it varies widely with respect to underlying pathophysiologic mechanisms, clinical presentations and, likely, treatments. It is the aim of this paper to describe some of the main clinical presentations of acute HF. Amongst them, we will consider de novo HF versus acutely decompensated chronic HF, HF caused, and/or worsened, by myocardial ischemia, acute HF with low, normal, or high systolic blood pressure, acute HF caused by lung congestion or fluid retention or fluid redistribution to the lungs, and acute HF with comorbidities (diabetes, anemia, renal insufficiency, etc.). Different pathophysiologic mechanisms and clinical presentations may coexist in the same patient. Identification and, whenever possible, treatment of underlying pathophysiologic mechanisms may become important for acute HF management.

The future of pharmacological therapy for heart failure

Current pharmacological therapy for heart failure (HF) is based on improved understanding of the pathophysiological mechanisms of HF progression. In particular, inhibition of key activated neurohormonal systems (eg, the renin-angiotensin-aldosterone system) and the sympathetic nervous system has been the cornerstone of drug therapy for this condition. However, despite these major advances, many HF patients still only marginally respond to these therapies. Novel therapeutic approaches have been tested. Several recent phase III studies have failed, however, despite intriguing pathophysiological concepts and promising pilot data. In other studies, significant benefits have been observed in certain subgroups only, suggesting the need for a more tailored approach to individual risk and comorbidity. This review will focus on recent and potential future pharmacological HF therapies and where drug treatment may be in the next few years. In discussing future pharmacological therapy for HF, 3 key strategies will be considered: (1) optimization of conventional therapies, (2) a focus on new drug development within areas not yet adequately represented by major clinical data and (3) new drugs affecting novel therapeutic targets.

Event-free survival in adults with heart failure who engage in self-care management

BACKGROUND

Self-care management in heart failure (HF) involves decision-making to evaluate, and actions to ameliorate symptoms when they occur. This study sought to compare the risks of all-cause mortality, hospitalization, or emergency-room admission among HF patients who practice above-average self-care management, those who practice below-average self-care management, and those who are symptom-free.

METHODS

A secondary analysis was conducted of data collected on 195 HF patients. A Cox proportional hazards model was used to examine the association between self-care management and event risk.

RESULTS

The sample consisted of older (mean ± standard deviation=61.3 ± 11 years), predominantly male (64.6%) adults, with an ejection fraction of 34.7% ± 15.3%; 60.1% fell within New York Heart Association class III or IV HF. During an average follow-up of 364 ± 288 days, 4 deaths, 82 hospitalizations, and 5 emergency-room visits occurred as first events. Controlling for 15 common confounders, those who engaged in above-average self-care management (hazard ratio, .44; 95% confidence interval, .22 to .88; P < .05) and those who were symptom-free (hazard ratio, 0.48; 95% confidence interval, .24 to .97; P < .05) ran a lower risk of an event during follow-up than those engaged in below-average self-care management.

CONCLUSION

Symptomatic HF patients who practice above-average self-care management have an event-free survival benefit similar to that of symptom-free HF patients.