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

Review of current and investigational pharmacologic agents for acute heart failure syndromes

Acute heart failure syndromes (AHFS) are a major public health problem and present a therapeutic challenge to clinicians. Commonly used agents in the treatment of AHFS include diuretics, vasodilators (eg, nitroglycerin, nitroprusside, nesiritide), and inotropes (eg, dobutamine, dopamine, milrinone). Patients admitted to hospital with AHFS and low cardiac output state (AHFS/LO) represent a subgroup with very high inhospital and postdischarge mortality rates. Most of these patients require intravenous inotropic therapy. However, the use of current intravenous inotropes has been associated with risk for hypotension, atrial and ventricular arrhythmias, and possibly increased postdischarge mortality, particularly in those with coronary artery disease. Consequently, there is an unmet need for new agents to safely improve cardiac performance (contractility and/or active relaxation) in this patient population. This article reviews a selection of current and investigational agents for the treatment of AHFS, with a main focus on the high-risk patient population with AHFS/LO.

A phase 1-2 dose-escalating study evaluating the safety and tolerability of istaroxime and specific effects on electrocardiographic and hemodynamic parameters in patients with chronic heart failure with reduced systolic function

Istaroxime (PST2744) is a luso-inotrope that stimulates the sarcoplasmic reticulum calcium adenosine triphosphatase isoform 2a without chronotropic effects. Additionally, it has beneficial effects on myocardial energetics. This phase 1-2 clinical trial in patients with chronic stable heart failure (HF) is the first evaluation of istaroxime in humans. Three cohorts of 6 patients each were exposed to 4 sequentially increasing 1-hour infusions with a random placebo. Doses were 0.005-5.0 micro/kg per min. Safety and hemodynamics were evaluated by impedance cardiography, digital Holter recorder, and electrocardiography. Pharmacokinetic data were obtained for 1 hour during treatment and for 6 hours after dosing. The mean age was 53+/-7 years, and the mean left ventricular ejection fraction was 0.27+/-0.08. Impedance cardiography demonstrated enhanced contractility as measured by the acceleration index, left cardiac work index, cardiac index, and pulse pressure at doses>or=1 micro/kg per min, with evidence of activity at doses of 0.5 micro/kg per min. Istaroxime shortened QTc. After infusion, the hemodynamic effect rapidly dissipated over 1-2 hours. Istaroxime was pharmacologically active and well tolerated at doses up to 3.33 micro/kg per min. Side effects were related to gastrointestinal symptoms and injection site pain at higher doses, which dissipated within minutes after the infusion ended. Ventricular ectopy was not altered. This study suggests that istaroxime is potentially useful in the treatment of HF and may offer a unique treatment for systolic and/or diastolic dysfunction. Additional studies are under way to further define its utility in acute HF.

Use and impact of inotropes and vasodilator therapy in hospitalized patients with severe heart failure

BACKGROUND

Treatment of decompensated heart failure often includes the use of intravenous vasoactive medications, but the effect on outcome has not been clearly defined.

METHODS

Data from 433 patients enrolled in the ESCAPE trial were analyzed to determine 6-month risks of all-cause mortality and all-cause mortality plus rehospitalization associated with the use of vasodilators, inotropes, and their combination. Patients had a mean left ventricular ejection fraction of 19%, 6-minute walk distance of 414 ft, and systolic blood pressure of 106 mm Hg. The main outcome measure was multivariable risk-adjusted 6-month hazard ratios (HRs).

RESULTS

Overall 6-month mortality was 19%. Risk-adjusted HRs were not statistically significant for vasodilators (1.39, 95% CI 0.64-3.00), but were significant for inotropes (2.14, 95% CI 1.10-4.15) and the combination (4.81, 95% CI 2.34-9.90). Risk-adjusted 6-month mortality plus rehospitalization HRs were not significant for vasodilators (1.20, 95% CI 0.81-1.78, P = .37), but were significant for inotropes (1.96, 95% CI 1.37-2.82, P < .001) and their combination (2.90, 95% CI 1.88-4.48, P = .001). The decision to use vasodilators or inotropes was determined by hemodynamic parameters and renal function, but the main factor was treatment site.

CONCLUSIONS

In ESCAPE, the choice of medications was mainly determined by the treatment site. Use of inotropic agents was associated with adverse outcomes, whereas the use of vasodilators was not. Inotropes in combination with vasodilators identified a group with the highest mortality. Prospective studies are needed to establish the appropriate use of vasoactive medications in this population.

Persistently Increased Serum Concentrations of Cardiac Troponin in Patients With Acutely Decompensated Heart Failure are Predictive of Adverse Outcomes

BACKGROUND

Persistently increased serum concentrations of cardiac troponin (cTn) are a prognostic marker in patients suffering from chronic congestive heart failure (CHF), but the significance in acute cardiac decompensation is unclear.

METHODS AND RESULTS

Serial blood samples were collected from 52 patients presenting with acute cardiac decompensation in the absence of an acute coronary event. Serial serum concentrations of cTnI, creatine kinase (CK)-MB, and brain natriuretic peptide (BNP) were measured by rapid assay. BNP and CK-MB steadily decreased from 902+/-529 pg/ml and 2.3+/-1.6 ng/ml at baseline to 453+/-427 pg/ml and 1.2+/-1.6 ng/ml on day 7, respectively, (p<0.0001 for both comparisons). In contrast, cTnI did not decrease significantly and, in 17 patients (35%), increased from 0.063+/-0.047 ng/ml at baseline to 0.167+/-0.181 ng/ml on day 1 (p<0.05). By single variable regression analysis, systolic blood pressure (SBP), use of inotropes or inodilators, vasodilators, and an initially elevated cTnI were predictors of elevated cTnI on day 1. By multiple variable analysis, an elevated SBP (as a mitigating factor) (odds ratios (OR) 0.12; 95% confidence intervals (CI): 0.02-0.76; p=0.0248), and high baseline cTnI (OR 13.85; 95%CI: 1.97-97.54; p=0.0083) were significant predictors of an elevated cTnI on day 1. Patients with elevated cTnI on day 1 had higher rates of worsening CHF and death from CHF than patients without such an increase (p<0.05).

CONCLUSIONS

Persistently increased serum concentrations of cTn in patients with acutely decompensated heart failure are predictive of adverse outcomes.

Racial Differences in the Characteristics of Patients Admitted for Acute Decompensated Heart Failure and Their Relation to Outcomes: Results From the OPTIME-CHF Trial

BACKGROUND

Recent data suggest that differences in response to therapy and survival exist between African Americans and Caucasians with heart failure. Whether these differences exist in acute decompensated heart failure (ADHF) is uncertain.

METHODS AND RESULTS

We analyzed data from the OPTIME-CHF (Outcomes of a Prospective Trial of Intravenous Milrinone for Exacerbations of Chronic Heart Failure) study, a randomized trial of intravenous milrinone versus placebo in 949 patients hospitalized with ADHF. We evaluated differences in clinical characteristics, outcomes, and response to milrinone therapy in African American patients compared with Caucasians. The primary end point of OPTIME-CHF was days hospitalized for cardiovascular causes or death within 60 days of randomization. Thirty-three percent (n = 310) of patients were African American. African American patients were younger (57 vs. 70 years, P < .0001) and more likely to have non-ischemic cardiomyopathy (74% vs. 36%, P < .0001). In unadjusted analysis, African American patients had a lower 60-day mortality (5% vs. 12%, P = .0004) and tended to have better overall clinical outcomes. After adjustment for baseline differences, however, these differences were no longer significant. We found no differential effect of milrinone therapy by race.

CONCLUSION

African American patients with acute decompensated heart failure present with a different clinical profile than Caucasian patients. Although unadjusted clinical outcomes are better for African Americans presenting with ADHF, these differences diminished after adjustment for baseline characteristics.

The Vasodilatory Effects of Levosimendan on the Human Internal Mammary Artery

BACKGROUND

Levosimendan, an inotropic drug that enhances myocardial contractility through myofilment calcium sensitazion, induces peripheral vasodilation via opening ATP-dependent K(+) channels. It is unknown whether this drug can be used for the treatment of perioperative vasospasm of arterial conduits used for coronary artery bypass grafting.

METHODS

We investigated the effects of levosimendan on human internal mammary artery (IMA) specimens taken from patients undergoing coronary artery bypass surgery. The rings were carefully prepared and placed between two wire hooks in organ bath chambers and then constricted submaximally with norepinephrine and thromboxane A(2) analog (U46619). Nitroglycerin, milrinone, and levosimendan were separately added in a cumulative fashion and concentration response curves for relaxation were constructed. In parallel experiments, the response to levosimendan was evaluated on rings with and without functional endothelium. Levosimendan prevention of norepinephrine-induced contraction was also estimated.

RESULTS

Nitroglycerin, milrinone, and levosimendan completely reversed the contraction of the IMA segments induced by U46619 and norepinephrine. Levosimendan produced a potent, concentration-dependent preventive effect on the norepinephrine-induced contraction of IMA. The responses to levosimendan were similar in preparations with or without endothelium.

Predictors of Clinical Outcome in Advanced Heart Failure Patients on Continuous Intravenous Milrinone Therapy

Home-based milrinone therapy (HMT) is used as a bridge to cardiac transplant (CT). The safety, efficacy, and predictors of success of HMT were assessed. Forty-five patients with heart failure, referred for CT, were prospectively studied. After initial assessment, low-dose milrinone was titrated based on clinical response. Hemodynamic status was then reevaluated. Thirty-nine patients were discharged on HMT. Patients needing a left ventricular assist device (LVAD) despite milrinone (group I) and those not requiring LVAD (group II) were compared. Six of the 45 patients were ineligible for CT; 16 of 39 required LVAD as a bridge to CT despite milrinone (group I); 23 were stable on milrinone and did not require LVAD (group II). Group I was younger than group II (mean age 38.4 +/- 14.5 years vs. 57.3 +/- 5.9 years, p < 0.001). Initial acute response to intravenous milrinone [e.g., fall in the PCWP (-10.7 +/- 9.5 vs. -2.7 +/- 10.4, p = 0.02), rise in pulmonary artery oxygen saturations (16.5 +/- 8.7 vs. 7.3 +/- 10.9, p = 0.05)] was significantly better in group II than in group I. Acute hemodynamic response to milrinone predicts success of HMT as a bridge to CT.

Outpatient continuous inotrope infusion as an adjunct to heart failure therapy in Duchenne muscular dystrophy

We report the use of continuous intravenous inotrope infusion as a palliative management strategy for the treatment of symptomatic, refractory, end stage cardiac dysfunction in patients with Duchenne muscular dystrophy. Milrinone and/or dobutamine administered by continuous intravenous infusion provided symptomatic and objective cardiovascular improvement up to 30 months in 3 individuals with Duchenne muscular dystrophy and severe dilated cardiomyopathy. Continuous inotrope infusion should be considered a practical treatment strategy for end stage cardiac dysfunction in Duchenne muscular dystrophy patients when cardiac transplantation is not a viable option.

Acute heart failure: inotropic agents and their clinical uses

Inotropic agents are indispensable for the improvement of cardiac contractile dysfunction in acute or decompensated heart failure. Clinically available agents, including sympathomimetic amines (dopamine, dobutamine, noradrenaline) and selective phosphodiesterase-3 inhibitors (amrinone, milrinone, olprinone and enoximone) act via cAMP/protein kinase A (PKA)-mediated facilitation of intracellular Ca2+ mobilisation. Phosphodiesterase-3 inhibitors also have a vasodilatory action, which plays a role in improving haemodynamic parameters in certain patients, and are termed inodilators. The available inotropic agents suffer from risks of Ca2+ overload leading to arrhythmias, myocardial cell injury and ultimately, cell death. In addition, they are energetically disadvantageous because of an increase in activation energy and cellular metabolism. Furthermore, they lose their effectiveness under pathophysiological conditions, such as acidosis, stunned myocardium and heart failure. Pimobendan and levosimendan (that act by a combination of an increase in Ca2+ sensitivity and phosphodiesterase-3 inhibition) appear to be more beneficial among existing agents. Novel Ca2+ sensitisers that are under basic research warrant clinical trials to replace available inotropic agents.

Acute perioperative heart failure

PURPOSE OF REVIEW

Changes in epidemiology and advances in the treatment of coronary artery disease, hypertension and diabetes mellitus have increased the prevalence of heart failure in the general population, and also the number of patients with heart failure presenting for surgery. Particularly in the perioperative period, patients with chronic heart failure are faced with numerous triggers of acute decompensation that can partly be avoided or treated. Patients without preexisting myocardial contractile dysfunction may sustain severe perioperative complications, e.g. myocardial infarction, with subsequent acute heart failure as a consequence. Approaches for diagnosis and treatment in these situations may vary considerably.

RECENT FINDINGS

Patients with preexisting heart failure undergoing non-cardiac surgery suffer substantial morbidity and mortality despite advances in perioperative care. The importance of heart failure as an independent risk factor is underlined by the fact that patients with coronary artery disease but without heart failure have a similar 30-day mortality rate to the general population. B-type natriuretic peptide testing is an attractive and non-invasive tool in non-surgical patients for the diagnosis of heart failure, but its role in the perioperative period for the diagnosis of myocardial contractile dysfunction is less clear. For inotropic support, levosimendan, a myofilament calcium sensitizer, has become available in several European countries, and encouraging positive reports have recently been published in this area.

SUMMARY

The role of B-type natriuretic peptide testing in the perioperative period is confounded by several variables that limit its use in that setting. New developments in positive inotropic therapy are challenging older and potentially harmful treatment strategies.

The long-term survival benefit conferred by intermittent dobutamine infusions and oral amiodarone is greater in patients with idiopathic dilated cardiomyopathy than with ischemic heart disease

BACKGROUND

Intermittent dobutamine infusions (IDI) combined with oral amiodarone improve the survival of patients with end-stage congestive heart failure (CHF). The purpose of the present study was to evaluate whether the response to long-term treatment with IDI+amiodarone is different in patients with ischemic heart disease (IHD) versus idiopathic dilated cardiomyopathy (IDC).

METHODS

The prospective study population consisted of 21 patients with IHD (the IHD Group) and 16 patients with IDC (the IDC Group) who presented with decompensated CHF despite optimal medical therapy, and were successfully weaned from an initial 72-h infusion of dobutamine. They were placed on a regimen of oral amiodarone, 400 mg/day and weekly IDI, 10 microg/kg/min, for 8 h.

RESULTS

There were no differences in baseline clinical and hemodynamic characteristics between the 2 groups. The probability of 2-year survival was 44% in the IDC Group versus 5% in the IHD Group (long-rank, P=0.004). Patients with IDC had a 77% relative risk reduction in death from all causes compared to patients with IHD (odd ratio 0.27, 95% confidence interval 0.13 to 0.70, P=0.007). In contrast, no underlying disease-related difference in outcomes was observed in a retrospectively analyzed historical Comparison Group of 29 patients with end stage CHF treated by standard methods.

CONCLUSIONS

Patients with end stage CHF due to IDC derived a greater survival benefit from IDI and oral amiodarone than patients with IHD.

Clinical profile, contemporary management and one-year mortality in patients with severe acute heart failure syndromes: The EFICA study

BACKGROUND

Little is known about the epidemiology of acute decompensated heart failure (ADHF) in patients admitted to intensive and coronary care units (ICU/CCU). Observational data may improve disease management and guide the design of clinical trials.

AIMS

EFICA is an observational study of the clinical profile, management and survival of ADHF patients admitted to ICU/CCU.

METHODS

The study included 599 patients admitted to 60 ICU/CCUs across France. Relevant data was recorded during hospitalisation. Survival was assessed at 4 weeks and 1 year.

RESULTS

The main cause of ADHF was ischaemic heart disease (61%); 29% of patients had cardiogenic shock. Mortality was 27.4% at 4 weeks and 46.5% at 1 year, increasing to 43.2% and 62.5%, respectively, when including pre-admission deaths. Shock patients had the highest [57.8% vs. 15.2% without shock (p < 0.001)] and patients with hypertension and pulmonary oedema had the lowest 4-week mortality: (7%). Pre-admission NYHA class III-IV heart failure, not initial clinical presentation, influenced 1-year mortality.

CONCLUSION

ADHF is a heterogeneous syndrome. Based on initial clinical presentation, three entities with distinct features and outcome may be described: cardiogenic shock, pulmonary oedema with hypertension, and 'decompensated' chronic heart failure. This should be taken into account in future observational studies, guidelines and clinical trials.

Short-term effects of levosimendan and prostaglandin E1 on hemodynamic parameters and B-type natriuretic peptide levels in patients with decompensated chronic heart failure

BACKGROUND

Both levosimendan and prostaglandin E1 (PGE1) have beneficial effects on hemodynamic parameters and outcome compared to dobutamine in decompensated chronic heart failure (CHF).

AIMS

We compared short-term effects of levosimendan versus PGE1 on hemodynamic parameters and B-type natriuretic peptide levels (BNP) in patients with decompensated CHF.

METHODS AND RESULTS

73 patients (cardiac index < 2.5 L/min/m2, pulmonary capillary wedge pressure (PCP) >15 mmHg) with decompensated CHF were randomised to treatment with either a 24 h-infusion of levosimendan (n=38) or a chronic infusion of PGE1 (n = 35). Hemodynamic parameters and BNP were measured at baseline, 24 and 48 h, BNP levels were also measured after 1 week. Baseline characteristics including concomitant medication were similar in both groups. Levosimendan and PGE1 increased cardiac output (CO) after 24 and 48 h. Levosimendan increased CO twice as much as PGE1 (24 h: Levosimendan +1.1 +/- 0.1 L/min, PGE1 +0.6 +/- 0.1 L/min, p < 0.001). Both drugs produced a comparable reduction in PCP and pulmonary artery pressure after 24 and 48 h. Levosimendan decreased BNP by 28% after 24 h and 22% after 48 h, but effects disappeared after 1 week. In contrast, PGE1 decreased BNP by 15% after 48 h (no change at 24 h), but a decrease of 20% was sustained at 1 week.

CONCLUSIONS

The differential beneficial effects of levosimendan (greater increase in CO) and PGE1 (sustained decrease in BNP) may have a potential impact on clinical outcome.

Calcium sensitizer agents: a new class of inotropic agents in the treatment of decompensated heart failure

The clinician's primary objective in treating a patient with decompensated heart failure is rapid and effective stabilization. This goal often is achieved through the use of inotropic support. Classic inotropic agents (beta-adrenergic agonists and phosphodiesterase III inhibitors) can provide short-term hemodynamic benefits, but their long-term use has been correlated with poor survival rates. Calcium sensitizers comprise a new drug class that offers hemodynamic and symptomatic improvements without increasing cAMP and intracellular calcium concentrations. These agents enhance contractility without a concurrent increase in the risk of cardiac events and thus represent a significant improvement over classic positive inotropic agents. Levosimendan is the most potent calcium sensitizer to date, exhibiting a unique dual mechanism of action that combines a positive inotropic action mediated via calcium sensitization and a vasodilator property via ATP-dependent potassium channels. Available clinical data suggest that calcium sensitizer agents represent a promising class of inotropic agents in a field that has seen few advances in recent decades.

New Directions in the Medical Management of Heart Failure

Like the introduction of digitalis more than 200 years ago, novel medical therapies today have the potential to significantly alter the course of heart failure (HF) and save thousands of lives. This review outlines new directions in HF medical management beyond the foundation of neurohormonal blockade. Furthermore, the role of novel risk factors in HF such as chronic renal insufficiency, anemia, and sleep apnea present tantalizing therapeutic targets to extend the morbidity and mortality benefits of current therapies. The course of time will tell which of these risk factors and therapies can hold promise, given the recent litany of negative trials in the HF arena. Advancements in molecular and genetic techniques have allowed us to begin to consider patient specific therapies and lay the groundwork for even further improvements in treatment of symptomatic HF. Finally, advances in telemedicine and device technology will allow the clinician to remotely monitor useful clinical parameters such as heart rate variability and pulmonary filling pressures to make more informed clinical decision-making and improve outcomes.

Molecular signature analysis: the potential of gene-expression analysis in cardiomyopathy

Despite the expanding knowledge base of the molecular and cellular pathophysiology and management of cardiomyopathy, it still remains difficult to accurately distinguish between patients who will someday develop circulatory collapse and require cardiac transplantation from those with excellent long-term prognosis. Of equal importance, current medical practice does not include strategies to tailor therapies to patients most likely to benefit, while at the same time seeking predictors of poor or adverse responsiveness. Gene-expression analysis using microarray technology, by providing a phenotypic resolution not possible with standard clinical criteria, has enormous potential to provide better information regarding prognosis and response to therapy in heart-failure patients. Emerging data demonstrate that a molecular signature can accurately identify etiology in cardiomyopathy, supporting ongoing efforts to identify expression profiling-based biomarkers, although microarray research in cardiomyopathy is still in its earliest stages. The ultimate potential application of transcriptome-based molecular signature analysis is individualization of the management of heart-failure patients, whereby a patient with a newly diagnosed cardiomyopathy could, through molecular signature analysis, be offered an accurate assessment of prognosis, and how individualized medical therapy could affect his or her outcome.

The Pilot Randomized Study of Nesiritide Versus Dobutamine in Heart Failure (PRESERVD-HF)

Acute heart failure syndromes (AHFS) are related to several diseases affecting not only the heart but also the kidneys and blood vessels. Emerging evidence indicates that myocardial injury may also play a role in the pathophysiology of AHFS, as suggested by increased levels of markers of injury, such as cardiac troponin (cTn). Although cTn is a known prognostic marker, the release of cTn during hospitalization has not been evaluated prospectively with serial measures. We prospectively evaluated patterns of cTn release by conducting serial measures of cTnI and cTnT in patients hospitalized for AHFS. This study enrolled 51 patients with AHFS who were admitted with worsening heart failure (HF) and a history of coronary artery disease (CAD) in whom an acute coronary event was not suspected. Levels of cTnI and cTnT were measured at 8, 32, 56, and 80 hours after study entry. At baseline, 73.9% of patients had detectable cTnI, and 43.5% had detectable cTnT levels. The median concentrations of cTnI and cTnT were unchanged from 0 to 32 hours, increased from 32 to 56 hours, then either plateaued (cTnT) or decreased to baseline (cTnI). Of the 26 patients who had no detectable cTn levels at baseline, 2 (7.7%) developed detectable cTnT and 5 (41.7%) developed detectable cTnI release during hospitalization. Detectable levels of cTn at baseline were related to short-term clinical events. In this study of patients with CAD in whom an acute coronary event was not suspected, most had detectable levels of cTn present at admission, and some patients developed cTn release during hospitalization. Because cTn release may be a marker for myocardial injury, this study raises the possibility that injury occurred in most patients admitted with AHFS. Therefore, the goal of therapy for AHFS should be not only to improve symptoms and hemodynamics but also to salvage myocardium. Accordingly, therapies for AHFS that are aimed at improving hemodynamics may affect long-term prognosis by either injuring or salvaging myocardium.

Reassessment of dobutamine, dopamine, and milrinone in the management of acute heart failure syndromes

The appropriate role of intravenous inodilator therapy (inotropic agents with vasodilator properties) in the management of acute heart failure syndromes (AHFS) has long been a subject of controversy, mainly because of the lack of prospective, placebo-controlled trials and a lack of alternative therapies. The use of intravenous inodilator infusions, however, remains common, but highly variable. As new options emerge for the treatment of AHFS, the available information should be reviewed to determine which approaches are supported by evidence, which are used empirically without evidence, and which should be considered inappropriate. For these purposes, we reviewed data available from randomized controlled trials on short-term, intermittent, and long-term use of intravenous inodilator agents (dobutamine, dopamine, and milrinone) in AHFS. Randomized controlled trials failed to show benefits with current medications and suggested that acute, intermittent, or continuous use of inodilator infusions may increase morbidity and mortality in patients with AHFS. Their use should be restricted to patients who are hypotensive as a result of low cardiac output despite a high left ventricular filling pressure.

Overview of randomized clinical trials in acute heart failure syndromes

Acute heart failure syndromes (AHFS) are among the most frequent causes of hospitalizations in the United States and Europe. Despite current therapies, patients with AHFS have high readmission and mortality rates. The randomized, controlled clinical trial is the standard by which contemporary therapies are evaluated, yet this tool of clinical science only recently has been rigorously applied to the development of novel therapies for patients with AHFS. This review briefly discusses some of the challenges presented in designing a clinical trial of therapies for AHFS and to describe some of the recent trials with respect to these issues in established drugs (such as milrinone, dobutamine, nitroglycerin, nitroprusside, and nesiritide) that have been approved by the US Food and Drug Administration (FDA). Recent trials of current investigational agents, such as levosimendan (the Randomized Multicenter Evaluation of Intravenous Levosimendan Efficacy Versus Placebo in the Short-Term Treatment of Decompensated Heart Failure [REVIVE], the Calcium Sensitizer or Inotrope or None in Low-Output Heart Failure [CASINO] study, and the Survival of Patients with Acute Heart Failure in Need of Intravenous Inotropic Support [SURVIVE] trial), tezosentan (the Randomized Intravenous Tezosentan [RITZ] study and the Value of Endothelin Receptor Inhibition with Tezosentan in Acute Heart Failure Studies [VERITAS]), and tolvaptan (the Acute and Chronic Therapeutic Impact of a Vasopressin Antagonist in Congestive Heart Failure [ACTIV-CHF] study), are also discussed.

A comparative study of discriminating human heart failure etiology using gene expression profiles

Background

Human heart failure is a complex disease that manifests from multiple genetic and environmental factors. Although ischemic and non-ischemic heart disease present clinically with many similar decreases in ventricular function, emerging work suggests that they are distinct diseases with different responses to therapy. The ability to distinguish between ischemic and non-ischemic heart failure may be essential to guide appropriate therapy and determine prognosis for successful treatment. In this paper we consider discriminating the etiologies of heart failure using gene expression libraries from two separate institutions.

Results

We apply five new statistical methods, including partial least squares, penalized partial least squares, LASSO, nearest shrunken centroids and random forest, to two real datasets and compare their performance for multiclass classification. It is found that the five statistical methods perform similarly on each of the two datasets: it is difficult to correctly distinguish the etiologies of heart failure in one dataset whereas it is easy for the other one. In a simulation study, it is confirmed that the five methods tend to have close performance, though the random forest seems to have a slight edge.

Conclusions

For some gene expression data, several recently developed discriminant methods may perform similarly. More importantly, one must remain cautious when assessing the discriminating performance using gene expression profiles based on a small dataset; our analysis suggests the importance of utilizing multiple or larger datasets.

Heart failure observation units: optimizing care

Heart failure causes substantial morbidity and mortality in the United States and accounts for a higher proportion of Medicare costs than any other disease. Most of these costs result from the high rate of hospital admissions and protracted length of stay associated with episodes of acute decompensation of heart failure. Thus, effective clinical strategies to obviate hospitalization and readmission can result in substantial savings. A specialized heart failure observation unit, in which patients receive rapid, goal-directed emergency care for heart failure symptoms, can be a critical component in this effort, providing intensive therapeutic monitoring and education. In institutions with specialized heart failure observation units, patients are triaged to this setting shortly after presentation to the emergency department (ED), and clinic referrals can be directed to this unit after minimal ED evaluation. Aggressive follow-up is also arranged at discharge. Recent additions to the therapeutic armamentarium and future advances in diagnostics and monitoring will continue to improve patient care and prevent avoidable hospitalizations.

In-hospital mortality in patients with acute decompensated heart failure requiring intravenous vasoactive medications: an analysis from the Acute Decompensated Heart Failure National Registry (ADHERE)

OBJECTIVES

We sought to compare the in-hospital mortality of patients with acute decompensated heart failure (ADHF) who were receiving parenteral treatment with one of four intravenous vasoactive medications.

BACKGROUND

There are limited data regarding the effects of the choice of intravenous vasoactive medication on in-hospital mortality in patients hospitalized with ADHF.

METHODS

This was a retrospective analysis of observational patient data from the Acute Decompensated Heart Failure National Registry (ADHERE), a multicenter registry designed to prospectively collect data on each episode of hospitalization for ADHF and its clinical outcomes. Data from the first 65,180 patient episodes (October 2001 to July 2003) were included in this analysis. Cases in which patients received nitroglycerin, nesiritide, milrinone, or dobutamine were identified and reviewed (n = 15,230). Risk factor and propensity score-adjusted odds ratios (ORs) for in-hospital mortality were calculated.

RESULTS

Patients who received intravenous nitroglycerin or nesiritide had lower in-hospital mortality than those treated with dobutamine or milrinone. The risk factor and propensity score-adjusted ORs for nitroglycerin were 0.69 (95% confidence interval [CI] 0.53 to 0.89, p < or = 0.005) and 0.46 (94% CI 0.37 to 0.57, p < or = 0.005) compared with milrinone and dobutamine, respectively. The corresponding values for nesiritide compared with milrinone and dobutamine were 0.59 (95% CI 0.48 to 0.73, p < or = 0.005) and 0.47 (95% CI 0.39 to 0.56, p < or = 0.005), respectively. The adjusted OR for nesiritide compared with nitroglycerin was 0.94 (95% CI 0.77 to 1.16, p = 0.58).

CONCLUSIONS

Therapy with either a natriuretic peptide or vasodilator was associated with significantly lower in-hospital mortality than positive inotropic therapy in patients hospitalized with ADHF. The risk of in-hospital mortality was similar for nesiritide and nitroglycerin.

Tezosentan in patients with acute heart failure: design of the Value of Endothelin Receptor Inhibition with Tezosentan in Acute heart failure Study (VERITAS)

BACKGROUND

Endothelin 1 is a potent endogenous vasoconstrictor neurohormone, and endothelin 1 plasma concentrations predict adverse outcomes in patients with acute heart failure (AHF). Tezosentan, an intravenous endothelin receptor antagonist, improved hemodynamics in patients with AHF; however, its effects on morbidity and mortality have not been evaluated.

METHODS

The VERITAS program consists of 2 identical, double-blind, randomized, placebo-controlled, concurrently conducted trials (VERITAS-1 and VERITAS-2), performed in 150 centers in Europe, Israel, Australia, and North America. The program is designed to enroll at least 1760 patients hospitalized with dyspnea at rest because of AHF requiring intravenous therapy. In addition to conventional therapy, patients are randomized to receive tezosentan (5 mg/h for 30 minutes, then 1 mg/h for 24-72 hours) or matching placebo. The 2 prespecified primary end points are the incidence of death or worsening heart failure at 7 days in the combined studies and the change from baseline in dyspnea over the first 24 hours of treatment, measured using a visual analog scale in VERITAS-1 and VERITAS-2, individually.

RESULTS

Enrollment started in April 2003, and the program was discontinued in November 2005 because of the low probability of achieving a significant treatment effect.

CONCLUSIONS

No currently available agents have been shown in a prospective, randomized, clinical trial to improve outcomes in patients with AHF. Thus, the VERITAS program will provide valuable insights into the effect of tezosentan on clinical outcomes in patients with AHF, as well as hemodynamics and clinical symptoms.

Gene expression analysis of ischemic and nonischemic cardiomyopathy: shared and distinct genes in the development of heart failure

Cardiomyopathy can be initiated by many factors, but the pathways from unique inciting mechanisms to the common end point of ventricular dilation and reduced cardiac output are unclear. We previously described a microarray-based prediction algorithm differentiating nonischemic (NICM) from ischemic cardiomyopathy (ICM) using nearest shrunken centroids. Accordingly, we tested the hypothesis that NICM and ICM would have both shared and distinct differentially expressed genes relative to normal hearts and compared gene expression of 21 NICM and 10 ICM samples with that of 6 nonfailing (NF) hearts using Affymetrix U133A GeneChips and significance analysis of microarrays. Compared with NF, 257 genes were differentially expressed in NICM and 72 genes in ICM. Only 41 genes were shared between the two comparisons, mainly involved in cell growth and signal transduction. Those uniquely expressed in NICM were frequently involved in metabolism, and those in ICM more often had catalytic activity. Novel genes included angiotensin-converting enzyme-2 (ACE2), which was upregulated in NICM but not ICM, suggesting that ACE2 may offer differential therapeutic efficacy in NICM and ICM. In addition, a tumor necrosis factor receptor was downregulated in both NICM and ICM, demonstrating the different signaling pathways involved in heart failure pathophysiology. These results offer novel insight into unique disease-specific gene expression that exists between end-stage cardiomyopathy of different etiologies. This analysis demonstrates that transcriptome analysis offers insight into pathogenesis-based therapies in heart failure management and complements studies using expression-based profiling to diagnose heart failure of different etiologies.

The Role of Hospitalists in the Management of Acute Decompensated Heart Failure

Heart failure and episodes of acute decompensated heart failure have an important effect on the US health care system, especially the elderly Medicare population. Efforts to improve the quality of care for patients hospitalized with acute decompensated heart failure have focused on creating standardized treatment guidelines based on substantial clinical evidence, but inadequate implementation of these guidelines continues to result in excess morbidity and mortality from heart failure. Hospitalists specializing in inpatient treatment strategies may play an important role in implementing clinical guidelines because their main commitment is to overall clinical treatment of inpatients. This review focuses on current recommended guidelines for diagnosis, treatment, and long-term management of patients with acute decompensated heart failure and the hospitalist's role in providing the oversight needed to adhere to these guidelines and manage this complex disease state.

The hemodynamic and neurohormonal effects of low doses of tezosentan (an endothelin A/B receptor antagonist) in patients with acute heart failure

BACKGROUND

In previous studies (the RITZ project), tezosentan, an intravenous (i.v.)-balanced dual endothelin (ET-A/B) antagonist, in doses of 50 and 100 mg/h, improved the hemodynamics but not the clinical outcome of patients with acute heart failure (AHF).

OBJECTIVE

To evaluate the effect of lower doses of tezosentan in patients with AHF.

SUBJECTS AND METHODS

Included were 130 patients hospitalized due to AHF with dyspnea at rest, despite initial treatment, and were in need of hemodynamic monitoring with cardiac index (CI)<2.5 l/min/m(2) and wedge pressure > or = 20 mm Hg. Patients were randomized in a double-blind fashion to receive placebo or tezosentan: 0.2, 1, 5, or 25 mg/h for 24 h.

RESULTS

The primary endpoint of the study, CI increase at 6 h of treatment, was significant in the 5 and 25 mg/h groups. Tezosentan induced a dose-dependent increase in CI and a decrease in wedge pressure, peaking after 3 h in the 5 and 25 mg/h groups. In the 1 mg/h group, this effect was smaller during the first 6 h and increased gradually, becoming significant at 24 h and beyond treatment discontinuation. There was no hemodynamic effect in the 0.2 mg/h arm. Type-B natriuretic peptide (BNP) decreased in the 1, 5, and 25 mg/h groups but not on placebo. Endothelin levels were significantly increased by the 5 and 25 mg/h groups but not in the lower (< or = 1 mg/h) tezosentan doses. Urine output decreased on the 25 mg/h dose. There was a trend towards improvement in patients' subjective dyspnea score and worsening heart failure events, mainly in the 1 mg/h group.

CONCLUSIONS

In patients admitted with AHF, tezosentan doses of 1-25 mg/h are efficacious in improving the hemodynamics and reducing BNP. Tezosentan doses beyond 1 mg/h increased plasma endothelin levels and reduced urine output, probably limiting their clinical efficacy, as compared to tezosentan 1 mg/h.

Significance of predischarge BNP on one-year outcome in decompensated heart failure—comparative study with echo-Doppler indexes

BACKGROUND

Cardiac natriuretic peptides and echo-Doppler indexes are important as prognostic indicators of congestive heart failure (CHF). However, differences between etiologies have not been fully investigated. This study aimed to assess the prognostic value of transmitral flow (TMF) and B-type natriuretic peptide (BNP) on admission or predischarge in patients with acutely decompensated CHF of ischemic and nonischemic etiologies.

METHODS AND RESULTS

We studied 52 patients with chronic CHF, 31 with old myocardial infarction (OMI), and 21 with idiopathic dilated cardiomyopathy (DCM), admitted for emergency acute decompensation. Patients underwent echo-Doppler study and measurement of plasma BNP on admission and predischarge. The combined index of BNP with echo-Doppler indexes were calculated. Pulmonary capillary wedge pressure (PCWP) and cardiac index were measured on admission. All were followed for 1 year, and those rehospitalized (R group) were compared with those with a stable clinical course (S group). TMF and BNP on admission were similar between DCM and OMI groups. During follow up, 9 with OMI and 10 with DCM were rehospitalized. There were no statistical differences in TMF or BNP levels on admission between the R and S groups. However, the predischarge BNP level was significantly higher in the R group than in the S. Kaplan-Meier curves revealed the influence of predischarge BNP on prognosis.

CONCLUSION

Predischarge BNP, not BNP on admission, levels are considered predictive of rehospitalization for decompensation within a year. There were no differences between BNP and echo-Doppler indexes with regard to the CHF etiology.

Identification of a gene expression profile that differentiates between ischemic and nonischemic cardiomyopathy

BACKGROUND

Gene expression profiling refines diagnostic and prognostic assessment in oncology but has not yet been applied to myocardial diseases. We hypothesized that gene expression differentiates ischemic and nonischemic cardiomyopathy, demonstrating that gene expression profiling by clinical parameters is feasible in cardiology.

METHODS AND RESULTS

Affymetrix U133A microarrays of 48 myocardial samples from Johns Hopkins Hospital (JHH) and the University of Minnesota (UM) obtained (1) at transplantation or left ventricular assist device (LVAD) placement (end-stage; n=25), (2) after LVAD support (post-LVAD; n=16), and (3) from newly diagnosed patients (biopsy; n=7) were analyzed with prediction analysis of microarrays. A training set was used to develop the profile and test sets to validate the accuracy of the profile. An etiology prediction profile developed in end-stage JHH samples was tested in independent samples from both JHH and UM with 100% sensitivity and 100% specificity in end-stage samples and 33% sensitivity and 100% specificity in both post-LVAD and biopsy samples. The overall sensitivity was 89% (95% CI 75% to 100%), and specificity was 89% (95% CI 60% to 100%) over 210 random partitions of end-stage samples into training and test sets. Age, gender, and hemodynamic differences did not affect the profile's accuracy in stratified analyses. Select gene expression was confirmed with quantitative polymerase chain reaction.

CONCLUSIONS

Gene expression profiling accurately predicts cardiomyopathy etiology, is generalizable to samples from separate institutions, is specific to disease stage, and is unaffected by differences in clinical characteristics. This strongly supports ongoing efforts to incorporate expression profiling-based biomarkers in determining prognosis and response to therapy in heart failure.

The use of recombinant human B-type natriuretic peptide (nesiritide) in the management of acute decompensated heart failure

Nesiritide is a synthetic human B-type natriuretic factor that has a balanced arterial and venous dilator effect, with natriuretic, diuretic, anti-aldosterone and antisympathetic action. It was launched in the US for the treatment of acute decompensated heart failure (ADHF) in August 2001 and, recently, in Switzerland and Israel. It has been demonstrated to provide more rapid and sustained haemodynamic stabilisation than glyceryl trinitrate and significant symptomatic improvement vs. placebo at 3 h, and to be safer than dobutamine. The main side effects associated with nesiritide therapy are asymptomatic and symptomatic hypotension, which are treated with dose reduction. When compared to dobutamine, the increased acquisition costs of nesiritide are completely offset by reduced intensity of hospital admissions and reduced readmission rate at 3 weeks.

The trefoil protein TFF1 is bound to MUC5AC in human gastric mucosa

The trefoil protein TFF1 is expressed principally in the superficial cells of the gastric mucosa. It is a small protein and forms homo- and hetero-dimers via a disulphide bond through Cys58 which is located three amino acids from the C terminus. TFF1 is co-expressed with the secreted mucin MUC5AC in superficial cells of the gastric mucosa suggesting that it could be involved in the packaging or function of gastric mucus. We have previously shown that TFF1 co-sediments with mucin glycoproteins on caesium chloride gradients. To extend this observation we have now used gel filtration under physiological conditions, immunoprecipitation and Western transfer analysis to characterise the interaction of TFF1 with gastric mucin glycoproteins. We show that TFF1 co-elutes with MUC5AC but not MUC6 on gel filtration and that immunoprecipitation and Western transfer analysis confirms that TFF1 interacts with MUC5AC. We also demonstrate that the TFF1 dimer is the predominant molecular form bound to MUC5AC. Salt and chelators of divalent cations such as EDTA and EGTA disrupted the TFF1- MUC5AC interaction and increased the degradation of MUC5AC, whereas calcium increased the amount of TFF1 bound to MUC5AC. These data support the contention that TFF1 is pivotal in the packaging and function of human gastric mucosa.

B-type natriuretic peptide: the level and the drug--partners in the diagnosis of congestive heart failure

Over the past 100 years, cardiovascular disease has become a leading cause of morbidity and mortality worldwide. A tremendous increase in incidence and prevalence of heart failure has been observed in the United States. The cost of managing heart failure itself is $56 billion a year, 70% of which is due to hospitalization. Although we have made tremendous advances in our understanding of the pathophysiology and treatment of congestive heart failure, the diagnosis of the disease still remains difficult. Unfortunately, the signs and symptoms of congestive heart failure are nonspecific. The recognition of the role of B-type natriuretic peptide as an objective marker for the diagnosis, severity, and prognosis of acute coronary syndromes and congestive heart failure was truly a breakthrough for clinicians and patients faced with cardiovascular disease. Also, the high levels of endogenous B-type natriuretic peptide may be released as a "distress hormone"; that is, these levels are no longer effective in maintaining the balance of vasoconstriction and vasodilation. Hence it makes intuitive and practical sense that giving back B-type natriuretic peptide in the form of exogenous nesiritide might restore neurohormonal homeostasis. Therefore, lately there has been a lot of interest shown in the use of recombinant B-type natriuretic peptide as a drug. This article reviews the literature concerning the use of these peptides in a variety of clinical scenarios and the use of recombinant B-type natriuretic peptide in decompensated heart failure.

Platelets, atherosclerosis and the endothelium: new therapeutic targets?

One of the major causes of morbidity and mortality in the developed world is atherosclerosis. Recent research has suggested that the interaction of platelets with the endothelium is important in both the progression of atherosclerosis and the development of the acute complications of the disease. Both of these cells secrete various signalling molecules and express adhesion molecules, which can influence the development of pathological states. Certainly, there may be a vicious cycle in which platelet activation promotes atherosclerosis; a process involving inflammation and the activation of many other cell types (for example, leukocytes and smooth muscle cells), which causes further platelet activation. Therefore, intense effort has been made to develop therapeutic agents that can modulate the function of these cells, with the ultimate aim to retard (or even reverse) the progression of atheroma growth.