What Is Evidence-Based, What Is New in Medical Therapy of Acute Heart Failure?

Acute decompensated heart failure (ADHF) has become the leading cause of hospitalization in patients > 65 years of age. Traditional drug therapy for ADHF has remained unchanged for many years including morphine, diuretics, nitrates and inotropic agents in addition to oxygen supplementation and mechanical ventilatory support, if necessary. In the year 2005, the European Society of Cardiology published new guidelines for diagnosis and treatment of ADHF. These guidelines emphasize that ADHF is not a disease entity but a complex syndrome with various etiologies and several distinct clinical conditions as a result of systolic and/or diastolic left and/or right ventricular dysfunction. This review article describes the current role of traditional drugs for ADHF as well as the role of newer concepts including vasodilators like the recombinant human brain peptide nesiritide, endothelin antagonists or vasopressin antagonists and newer inotropic agents like the calcium sensitizer levosimendan.     

Hyponatremia in acute heart failure syndromes: A potential therapeutic target

Mild hyponatremia is common in patients hospitalized for worsening heart failure, and it is a major predictor of post-discharge mortality and morbidity irrespective of left ventricular ejection fraction. Recent data also suggest that standard therapy for heart failure does not improve or normalize serum sodium concentration during hospitalization. There are conclusive data that vasopressin antagonists improve or normalize serum sodium in this patient population. However, it is not known if this improvement or normalization in serum sodium is associated with an improvement in post-discharge outcomes. Future trials with vasopressin antagonists in patients hospitalized with worsening heart failure and hyponatremia are in order.     

Targeting Hyponatremia and Hemodynamics in Acute Decompensated Heart Failure: Is There a Role for Vasopressin Antagonists?

Current treatment of acute decompensated heart failure (ADHF) has not reduced the significant morbidity or mortality associated with this disease, and has promoted drug development aimed at neurohormonal targets. Hypervolemic hyponatremia, which is linked to the nonosmotic release of arginine vasopressin, is associated with a poor prognosis in patients with heart failure (HF). Vasopressin acts on V₂ and V_1a receptors to cause water retention and vasoconstriction, respectively. Clinical trials have demonstrated that vasopressin receptor antagonists (VRAs) are effective in treating hypervolemic hyponatremia in ADHF without a negative impact on renal function. The small hemodynamic benefit seen with VRA use appeared to result from V₂-receptor antagonist–induced increase in urine output rather than from a vasodilatory drug effect. VRA use in ADHF trials was associated with minimal symptomatic improvement and no impact on morbidity or mortality. At present, clinical trial evidence does not support the routine use of VRAs in ADHF. Given the favorable renal profile of VRAs, studies on the possible benefit of VRAs in ADHF patients with renal insufficiency and diuretic resistance appear warranted.     

Novel therapies for heart failure: vasopressin and selective aldosterone antagonists

Despite favorable improvements in mortality, heart failure (HF) remains a problematic illness due to the ever-present burden of hospitalization. Clearly, novel treatment strategies are needed. This review focuses on two newer pharmacologic targets: arginine vasopressin and aldosterone. Arginine vasopressin receptor antagonists will most likely serve as an adjunct to or replacement of standard diuretic therapy in selected patients. The safety and efficacy of chronic therapy with oral arginine vasopressin receptor antagonists in large groups of congestive HF patients is currently under investigation. Aldosterone antagonism is emerging as a treatment of severe congestive HF. Recent large-scale clinical trials using aldosterone antagonists have proven that those with HF or left ventricular dysfunction postmyocardial infarction derive a survival benefit from aldosterone antagonism. Whether aldosterone antagonism should be prescribed in all patients with HF is unclear; however, in carefully selected and managed patients, aldosterone antagonism is helpful.     

Hyponatremia in acute decompensated heart failure: mechanisms, prognosis, and treatment options

Hyponatremia is common and is increasingly recognized as an independent prognostic marker that adversely affects morbidity and mortality in various disease states, including heart failure. In acute decompensated heart failure (ADHF), the degree of hyponatremia often parallels the severity of cardiac dysfunction and is further exacerbated by any reduction in glomerular filtration rate and arginine vasopressin dysregulation. A recent study showed that even modest improvement of hyponatremia may have survival benefits. Although management of hyponatremia in ADHF has traditionally focused on improving cardiac function and fluid restriction, the magnitude of improvement of serum sodium is fairly slow and unpredictable. In this article, we discuss the mechanisms of hyponatremia in ADHF, review its evolving prognostic significance, and evaluate the efficacy of various treatments for hyponatremia, including the recently approved vasopressin receptor antagonists for managing hyponatremia among patients hospitalized for ADHF.     

Heart Failure With Midrange Ejection Fraction in Patients Admitted for Acute Decompensation: A Report from the Japanese Multicenter Registry

BackgroundPatients having heart failure with midrange ejection fraction (HFmrEF: 40% ≤ EF < 50%) are increasingly being considered a new subset of the population with heart failure. Despite recent advances in heart-failure treatment strategies, the prognosis of these patients has not improved substantially over time. In addition, the significance of this new phenotype in hospitalized patients with acute decompensated heart failure (ADHF), another population whose prognosis has not improved, also remains poorly understood. This study aimed to describe the clinical characteristics, prognosis and treatment responses of patients with HFmrEF hospitalized for ADHF.MethodsOn the basis of consecutive inpatient data from a multicenter ADHF registry, 651 of 3572 patients (17.1%) were classified as having HFmrEF. Prognostic factors predicting composite outcomes, defined as all-cause death and heart failure readmission, as well as all-cause death alone, were analyzed.ResultsIn the median follow-up duration of 724 days, both composite endpoints and all-cause death alone were comparable in those with heart failure with preserved ejection fraction, HFmrEF and heart failure with reduced ejection fraction. Age, anemia, hyponatremia, elevated blood urea nitrogen, chronic kidney disease, and elevated plasma brain natriuretic peptide levels were significant predictors of composite outcomes in HFmrEF.ConclusionsRoughly one-sixth of the patients with ADHF had HFmrEF. The long-term prognosis of patients with HFmrEF was not significantly different from that of patients with heart failure with preserved ejection fraction and heart failure with reduced ejection fraction in the population with ADHF. Risk factors for adverse outcomes in HFmrEF were also similar to those for heart failure with preserved ejection fraction and HFmrEF in the hospitalized population with ADHF.     

Review of Vasodilators in Acute Decompensated Heart Failure: The Old and the New

Despite substantial improvements in treatment for chronic heart failure, morbidity and mortality for acute decompensated heart failure (ADHF) remain high. Treatment of ADHF is focused on controlling symptoms rather than improving long-term outcomes. The vasodilators nitroglycerin (NTG) and sodium nitroprusside (SNP) have been used in ADHF for decades, but, since the development of nesiritide 10 years ago, interest in new vasodilators has grown. Therapies that improve not only hemodynamics and symptoms but also long-term outcomes are in high demand, and numerous new vasodilatory agents have been investigated, including various natriuretic peptides, soluble guanylyl cyclase agents, renin-angiotensin-aldosterone system–modifying agents, and others. A review of the literature shows that few of them rise to the challenge set by NTG and SNP.     

Heart failure

This article discusses the most important developments in heart failure reported during the last year. It contains a review of new findings on chronic heart failure, acute heart failure, cardiac resynchronization therapy, heart transplantation, with particular emphasis on the situation in Spain, and surgery in heart failure. In addition, the article describes progress in the treatment of anemia, vasopressin receptor antagonists, non-invasive ventilation, inotropic therapy, and resynchronization therapy in patients with heart failure and atrial fibrillation, and examines the current role of echocardiography in detecting asynchrony and in selecting patients.     

Dual Vasopressin V1a/V2 Antagonism: The Next Step in Neurohormonal Modulation in Patients With Heart Failure?

Stimulation of the V1a receptor for arginine vasopressin produces myocardial and vascular effects similar to those of angiotensin II while stimulation of the V2 receptor causes fluid retention. There are no data with sustained blockade of the V1a receptor while single-dose experiments suggest benefit. Acute and chronic administration of selective V2 receptor antagonists reliably relieves dyspnea and produces diuresis without adverse effects on renal function or neurohormonal stimulation, either as adjunctive or alternative therapy to loop diuretics, but has not been shown to improve outcomes as adjunctive therapy. Combined antagonism has been tried only in single-dose studies in stable patients or over the short-term in acute heart failure, with encouraging results. Based on the both the pathophysiologic rationale for additional neurohormonal blockade and these results, chronically blocking both receptors, particularly in more congested patients, may offer significant benefit either as adjunctive or alternative therapy to standard diuretics.     

Overview of acutely decompensated congestive heart failure (ADHF): a report from the ADHERE registry

Acute decompensated heart failure (ADHF) has emerged as a major public health problem, and HF has become the leading cause of hospitalization in persons over 65 years of age. It is estimated that there are 6.5 million hospital days attributed to ADHF each year. Patients hospitalized with ADHF face a substantial risk of readmission, as high as 50% by 6 months after discharge. Despite the large number of patients hospitalized and this substantial risk, data on these patients have been limited and there has been little effort to improve the quality of care for patients hospitalized with ADHF. The Acute Decompensated Heart Failure National Registry (ADHERE) was designed to bridge this gap in knowledge and care by prospectively studying the characteristics, management, and outcomes of a broad spectrum of patients hospitalized with ADHF. Participating community and university hospitals identified patients with a primary or secondary discharge diagnosis of HF and collected medical history, management, treatments, and health outcomes via secure Web browser technology. As of October 2004, more than 160,000 patients from 281 hospitals have been enrolled. These patients differ substantially from those typically enrolled in randomized clinical trials. Initial data from the ADHERE registry have provided important insights into the clinical characteristics, patterns of care, and outcomes of patients with ADHF. ADHERE has documented significant delays in diagnosis and initiation of ADHF therapies as well as a substantial under-use of evidenced-based, guideline-recommended chronic HF therapies at hospital discharge. As such, there are substantial opportunities to improve the quality of care for ADHF patients in the nation's hospitals.     

Update on recent clinical trials in congestive heart failure

Understanding of the pathophysiology of heart failure has advanced over the last decade, resulting in new therapeutic advances. Convincing data exist that angiotensin-converting enzyme (ACE) inhibition and adrenergic blockade are the most important therapies and have the capacity to improve survival and lower morbidity. Higher doses of both ACE inhibitors and beta-blockers appear to provide additional benefits. The aldosterone antagonist spironolactone, when used in severe heart failure, provides additional survival advantage when added to standard triple therapy. Angiotensin receptor blockers have not been shown to be superior to ACE inhibitors, and their role in heart failure treatment requires further investigation. No trial's data support the use of inotropic agents or calcium channel blockers in heart failure. A number of new therapeutic agents, including vasopressin antagonists and tumor necrosis factor-alpha receptor antibody are in phase II and III clinical trials. If proved beneficial, they may provide new treatment options for patients with heart failure. Nevertheless, the current challenge is to increase the use of proven therapies, namely ACE inhibitors and beta-blockers, to improve outcomes in the rapidly growing population of patients with congestive heart failure.     

Hyponatremia in patients with heart failure

The present review analyses the mechanisms relating heart failure and hyponatremia,describes the association of hyponatremia with the progress of disease and morbidity/mortality in heart failure patients and presents treatment options focusing on the role of arginine vasopressin(AVP)-receptor antagonists.Hyponatremia is the most common electrolyte disorder in the clinical setting and in hospitalized patients.Patients with hyponatremia may have neurologic symptoms since low sodium concentration produces brain edema,but the rapid correction of hyponatremia is also associated with major neurologic complications.Patients with heart failure often develop hyponatremia owing to the activation of many neurohormonal systems leading to decrease of sodium levels.A large number of clinical studies have associated hyponatremia with increased morbidity and mortality in patients hospitalized for heart failure or outpatients with chronic heart failure.Treatment options for hyponatremia in heart failure,such as water restriction or the use of hypertonic saline with loop diuretics,have limited efficacy.AVP-receptor antagonists increase sodium levels effectively and their use seems promising in patients with hyponatremia.However,the effects of AVP-receptor antagonists on hard outcomes in patients with heart failure and hyponatremia have not been thoroughly examined.     

Hyponatremia and vasopressin antagonism in congestive heart failure

In a national heart failure registry, hyponatremia (serum sodium < 130 mEq/L) was initially reported in 5% of patients and considered a risk factor for increased morbidity and mortality. In a chronic heart failure study, serum sodium level on admission predicted an increased length of stay for cardiovascular causes and increased mortality within 60 days of discharge. Hyponatremia in patients with congestive heart failure (CHF) is associated with a higher mortality rate. Also, by monitoring and increasing serum sodium levels during hospitalization for CHF, patient outcomes may improve. This review describes the pathophysiology of hyponatremia in relation to CHF, including the mechanism of action of vasopressin receptors in the kidney, and assesses the preclinical and clinical trials of vasopressin receptor antagonists--agents recently developed to treat hyponatremia. In hospitalized patients with CHF, hyponatremia plays a major role in poor outcomes. Vasopressin receptor antagonists have been shown to be safe and effective in clinical trials in patients with hyponatremia.     

Managing acute renal failure in patients with acute decompensated heart failure: The cardiorenal syndrome

In patients with acute decompensated heart failure, worsening renal function during conventional decongestive therapy (cardiorenal syndrome) affects prognosis and the initiation of therapies with known benefit in chronic heart failure. Potential strategies for decongestion in patients who develop cardiorenal syndrome include invasive hemodynamic monitoring to guide therapy, use of continuous diuretic infusions, ultrafiltration, or novel therapy with adenosine or vasopressin receptor antagonists. Clinical trials by the National Heart, Lung, and Blood Institute’s Heart Failure Network are currently underway to validate such therapies in patients with acute decompensated heart failure with worsening renal function and to establish novel biomarkers for the early identification of patients who develop cardiorenal syndrome.     

Clinical benefit of tolvaptan in patients with acute decompensated heart failure and chronic kidney disease

Tolvaptan, a vasopressin type 2 receptor antagonist, has an aquaretic effect without affecting renal function. The effects of long-term tolvaptan administration in heart failure patients with renal dysfunction have not been clarified. Here, we assessed the clinical benefit of tolvaptan during a 6-month follow-up in acute decompensated heart failure (ADHF) patients with severe chronic kidney disease (CKD; estimated glomerular filtration rate (eGFR) <45 mL/min/1.73 m²). We compared 33 patients with ADHF and severe CKD who were administered tolvaptan in addition to loop diuretics (TLV group), with 36 patients with ADHF and severe CKD who were administered high-dose loop diuretics (≥40 mg) alone (LD group). Alterations in serum creatinine and eGFR levels from the time of hospital discharge to 6-month follow-up were significantly different between the groups, with those in the TLV group being more favorable. Furthermore, Kaplan–Meier analysis revealed that rehospitalization for heart failure (HF) was significantly lower in the TLV group compared with the LD group. In ADHF patients with severe CKD, tolvaptan use for 6 months reduced worsening of renal function and rehospitalization rates for HF when compared with conventional diuretic therapy. In conclusion, tolvaptan could be a safe and effective agent for long-term management of HF and CKD.     

Role of Adenosine Antagonism in the Cardiorenal Syndrome

Acute decompensated heart failure (ADHF), generally related to signs and symptoms of volume overload, is one the most common reasons for hospitalization in the United States. Recently, it has been observed that the majority of patients with ADHF have baseline renal dysfunction. Moreover, heart failure (HF) treatment is limited by worsening renal function despite persistent volume overload. This connection between HF and renal dysfunction has been termed the cardiorenal syndrome and has made treatment of patients with stable and unstable HF challenging. Selective adenosine A1 receptor antagonists are novel pharmacologic agents that are currently under development to treat volume overload in HF while protecting or possibly improving renal function. In this article, we review the cardiorenal syndrome, the role of adenosine in renal function, and emerging data regarding the safety and efficacy of adenosine A1 receptor antagonists in patients with advanced HF.     

Outpatient intravenous diuretic therapy; potential for marked reduction in hospitalisations for acute decompensated heart failure

BACKGROUND: Heart failure patients have frequent readmissions for acute decompensated heart failure (ADHF). AIMS: To examine the feasibility, safety and outcomes of outpatient intravenous (IV) diuretic therapy in treating ADHF. METHODS: A retrospective analysis was performed of all patients included in a hospital-based heart failure disease management programme, who received outpatient IV diuretic therapy for the management of ADHF between 2002 and 2006. Changes in clinical and biochemical parameters from time of therapy to stability were measured. RESULTS: One hundred and seven patients (mean age 71+/-11 years) received outpatient IV diuretic therapy for ADHF IV diuretic administration reduced weight (p<0.001), blood pressure (p<0.01) and BNP (p=0.01). It increased urea (p=0.01) and creatinine (p=0.07). Seventy-two percent of patients stabilised following IV diuretics and did not require admission. No patients were hospitalised for hypotension or hypokalaemia. One patient was hospitalised for renal failure. Two patients died post admission. CONCLUSION: Outpatient IV diuretic administration for ADHF is safe, cost effective and reduces hospitalisations. This service may expand the potential of a disease management programme to manage ADHF out of hospital and thereby reduce the hospital dependency of this condition.     

How to use diuretics in heart failure

Systemic and pulmonary congestion is a central aspect of both acute and chronic heart failure and directly leads to many of the clinical manifestations of these syndromes. Therefore, diuretic therapy to treat congestion plays a fundamental role in heart failure management. However, although diuretics are the most common drugs prescribed for heart failure, there is limited quality evidence to guide their use. Unlike other components of the heart failure armamentarium, such as β-blockers and angiotensin-converting enzyme inhibitors, diuretics (with the exception of aldosterone antagonists) have not been shown to decrease heart failure progression or improve mortality. Additionally, some observational data suggest that diuretics may actually be harmful in heart failure, contributing to neurohormonal activation, renal dysfunction, and potentially mortality. Despite these concerns, diuretics remain ubiquitous in heart failure management because of the need to address symptoms of congestion and the lack of alternative strategies. Recently, the development of a variety of potential adjuncts or alternatives to diuretic therapy has suggested the need for an active reappraisal of diuretic therapy for heart failure. The main classes of diuretics are the loop diuretics, potassium-sparing diuretics, and thiazides. Loop diuretics, the mainstay of acute and chronic therapy for heart failure, are “threshold drugs”; therefore, an adequate dose to achieve a pharmacodynamic effect (ie, to increase urine output) must be prescribed for effective therapy. The minimum dose to achieve diuresis and manage congestion should be used to minimize adverse effects. For patients refractory to initial dosing of intravenous diuretics, options include dose escalation, use of continuous infusion rather than intermittent boluses, or combination therapy with the addition of a thiazide or thiazide-like diuretic (eg, metolazone). Management of chronic heart failure often includes patient-directed titration of diuretics based on changes in symptoms or body weight in an attempt to decrease hospitalizations, although the efficacy of this strategy has not been tested in well-designed trials. Aldosterone antagonists, which are used primarily as neurohormonal agents rather than for their diuretic effects, are indicated for patients with systolic failure and moderate to severe symptoms, as long as renal function and serum potassium are stable and monitored closely. All diuretic therapy requires careful monitoring of electrolytes and renal function. Whether newer modalities for managing congestion (vasopressin antagonists, adenosine A1 antagonists, and ultrafiltration therapy) will be an improvement over diuretic therapy will be determined by the results of multiple ongoing clinical trials.     

Potential of endothelin-1 and vasopressin antagonists for the treatment of congestive heart failure

It is now becoming clear that two major systems namely the sympathetic nervous system and the renin-angiotensin system are activated in response to ischemic injury; these result in the elevation of plasma catecholamines and angiotensin II during the development of myocardial infarction as well as congestive heart failure. Although plasma levels of several other hormones including aldosterone, endothelin, vasopressin, natriuretic peptides, growth factors and inflammatory cytokines are also increased in heart failure, their relationship with changes in catecholamine and/or angiotensin levels as well as their significance for the induction of congestive heart failure are poorly understood. In this article we have examined the evidence regarding the role of endothelin and vasopressin in the pathogenesis of cardiac hypertrophy and congestive heart failure in addition to evaluating the significance of their antagonism by using their receptor blockade for treatment of congestive heart failure. Endothelin appears to maintain blood pressure by its vasoconstricting action whereas vasopressin primarily produces similar effect by retention of body fluid. Myocardium is also known to express both ET-A and ET-B receptors in addition to V₁ and V₂ receptors for vasopressin, which have been shown to induce cardiac remodeling. Out of various ET-1 receptor antagonists, which are available, a non-selective endothelin receptor antagonist, bosentan, as well as an ET-A receptor antagonist, BQ-123, seem most promising for the treatment of congestive heart failure. Likewise, vasopressin antagonists such as a non-selective antagonist, conivaptan, as well as V₂ selective antagonist, tolvaptan, may prove highly valuable for the therapy of this condition. Since most of the existing interventions are helpful in treating patients with congestive heart failure only partially, there appears to be a real challenge for developing some combination therapy for the treatment of congestive heart failure.     

Management of acute decompensated heart failure

Acute decompensated heart failure is the most common cause for hospitalization among patients over 65 years of age. It may result from new onset of ventricular dysfunction or, more typically, exacerbation of chronic heart failure symptoms. In-hospital mortality remains high for both systolic and diastolic forms of the disease. Therapy is largely empirical as few randomized, controlled trials have focused on this population and consensus practice guidelines are just beginning to be formulated. Treatment should be focused upon correction of volume overload, identifying potential precipitating causes, and optimizing vasodilator and beta-adrenergic blocker therapy. The majority of patients (>90%) will improve without the use of positive inotropic agents, which should be reserved for patients with refractory hypotension, cardiogenic shock, end-organ dysfunction, or failure to respond to conventional oral and/or intravenous diuretics and vasodilators. The role of aldosterone antagonists, biventricular pacing, and novel pharmacological agents including vasopressin antagonists, endothelin blockers, and calcium-sensitizing agents is also reviewed.