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

Could Endothelin-1 Be a Promising Neurohormonal Biomarker in Acute Heart Failure?

Acute heart failure (AHF) is a life-threatening condition with high morbidity and mortality. Even though this pathology has been extensively researched, there are still challenges in establishing an accurate and early diagnosis, determining the long- and short-term prognosis and choosing a targeted therapeutic strategy. The use of reliable biomarkers to support clinical judgment has been shown to improve the management of AHF patients. Despite a large pool of interesting candidate biomarkers, endothelin-1 (ET-1) appears to be involved in multiple aspects of AHF pathogenesis that include neurohormonal activation, cardiac remodeling, endothelial dysfunction, inflammation, atherosclerosis and alteration of the renal function. Since its discovery, numerous studies have shown that the level of ET-1 is associated with the severity of symptoms and cardiac dysfunction in this pathology. The purpose of this paper is to review the existing information on ET-1 and answer the question of whether this neurohormone could be a promising biomarker in AHF.

Early drop in systolic blood pressure is associated with poor diuretic response and prognosis in patients with acute heart failure

AIMS

Although an excessive drop in systolic blood pressure (SBP) during acute heart failure (AHF) negatively impacts prognosis, the association between changes in SBP and the diuretic response (DR) is unclear. We aimed to clarify the association between an early drop in SBP and DR/prognosis in patients with AHF.

METHODS AND RESULTS

This was a sub-analysis of the REALITY-AHF study, which registered patients with AHF admitted through emergency departments (EDs). An early SBP drop was defined as the difference between baseline SBP and the lowest value during the first 48 h of hospitalization. DR was defined as the urine output achieved per 40 mg of intravenous furosemide administered. SBP was measured on admission, at 90 min, and 6, 24, and 48 h after admission. Patients were divided into four groups according to their median SBP drop and DR: greater SBP drop/poor DR (n = 322), smaller SBP drop/poor DR (n = 409), greater SBP drop/good DR (n = 419), and smaller SBP drop/good DR (n = 314). The study included 1,464 patients. A greater SBP drop/poor DR was associated with higher baseline SBP and vasodilator use. Multivariable linear regression analysis showed that a greater drop in SBP was associated with poorer DR following adjustment for potential covariates. Cox proportional hazards analysis demonstrated that a greater SBP drop/poor DR was independently associated with 1-year mortality. Both SBP and DR changes were independently associated with prognosis.

CONCLUSION

An early drop in SBP during the first 48 h of hospitalization was associated with poor DR and 1-year mortality in patients with AHF.

CLINICAL TRIAL REGISTRATION

URL: http://www.umin.ac.jp/ctr/Unique identifier: UMIN000014105.

Prognostic role of albumin level in heart failure: A systematic review and meta-analysis

BACKGROUND

Hypoalbuminemia (HA) is common in HF, however, its pathophysiology and clinical implications are poorly understood. While multiple studies have been published in the past decade investigating the role of serum albumin in HF, there is still no consensus on the prognostic value of this widely available measure. The objective of this study is to assess the prognostic role of albumin in heart failure (HF) patient.

METHODS

Unrestricted searches of MEDLINE, EMBASE, Cochrane databases were performed. The results were screened for relevance and eligibility criteria. Relevant data were extracted and analyzed using Comprehensive Meta-Analysis software. The Begg and Mazumdar rank correlation test was utilized to evaluate for publication bias.

RESULTS

A total of 48 studies examining 44,048 patients with HF were analyzed. HA was found in 32% (95% confidence interval [CI] 28.4%-37.4%) HF patients with marked heterogeneity (I2 = 98%). In 10 studies evaluating acute HF, in-hospital mortality was almost 4 times more likely in HA with an odds ratios (OR) of 3.77 (95% CI 1.96-7.23). HA was also associated with a significant increase in long-term mortality (OR: 1.5; 95% CI: 1.36-1.64) especially at 1-year post-discharge (OR: 2.44; 95% CI: 2.05-2.91; I2 = 11%). Pooled area under the curve (AUC 0.73; 95% CI 0.67-0.78) was comparable to serum brain natriuretic peptide (BNP) in predicting mortality in HF patients.

CONCLUSION

Our results suggest that HA is associated with significantly higher in-hospital mortality as well as long-term mortality with a predictive accuracy comparable to that reported for serum BNP. These findings suggest that serum albumin may be useful in determining high-risk patients.

Pharmacological interventions for heart failure in people with chronic kidney disease

BACKGROUND

Approximately half of people with heart failure have chronic kidney disease (CKD). Pharmacological interventions for heart failure in people with CKD have the potential to reduce death (any cause) or hospitalisations for decompensated heart failure. However, these interventions are of uncertain benefit and may increase the risk of harm, such as hypotension and electrolyte abnormalities, in those with CKD.

OBJECTIVES

This review aims to look at the benefits and harms of pharmacological interventions for HF (i.e., antihypertensive agents, inotropes, and agents that may improve the heart performance indirectly) in people with HF and CKD.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies through 12 September 2019 in consultation with an Information Specialist and using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

We included randomised controlled trials of any pharmacological intervention for acute or chronic heart failure, among people of any age with chronic kidney disease of at least three months duration.

DATA COLLECTION AND ANALYSIS

Two authors independently screened the records to identify eligible studies and extracted data on the following dichotomous outcomes: death, hospitalisations, worsening heart failure, worsening kidney function, hyperkalaemia, and hypotension. We used random effects meta-analysis to estimate treatment effects, which we expressed as a risk ratio (RR) with 95% confidence intervals (CI). We assessed the risk of bias using the Cochrane tool. We applied the GRADE methodology to rate the certainty of evidence.

MAIN RESULTS

One hundred and twelve studies met our selection criteria: 15 were studies of adults with CKD; 16 studies were conducted in the general population but provided subgroup data for people with CKD; and 81 studies included individuals with CKD, however, data for this subgroup were not provided. The risk of bias in all 112 studies was frequently high or unclear. Of the 31 studies (23,762 participants) with data on CKD patients, follow-up ranged from three months to five years, and study size ranged from 16 to 2916 participants. In total, 26 studies (19,612 participants) reported disaggregated and extractable data on at least one outcome of interest for our review and were included in our meta-analyses. In acute heart failure, the effects of adenosine A1-receptor antagonists, dopamine, nesiritide, or serelaxin on death, hospitalisations, worsening heart failure or kidney function, hyperkalaemia, hypotension or quality of life were uncertain due to sparse data or were not reported. In chronic heart failure, the effects of angiotensin-converting enzyme inhibitors (ACEi) or angiotensin receptor blockers (ARB) (4 studies, 5003 participants: RR 0.85, 95% CI 0.70 to 1.02; I² = 78%; low certainty evidence), aldosterone antagonists (2 studies, 34 participants: RR 0.61 95% CI 0.06 to 6.59; very low certainty evidence), and vasopressin receptor antagonists (RR 1.26, 95% CI 0.55 to 2.89; 2 studies, 1840 participants; low certainty evidence) on death (any cause) were uncertain. Treatment with beta-blockers may reduce the risk of death (any cause) (4 studies, 3136 participants: RR 0.69, 95% CI 0.60 to 0.79; I² = 0%; moderate certainty evidence). Treatment with ACEi or ARB (2 studies, 1368 participants: RR 0.90, 95% CI 0.43 to 1.90; I² = 97%; very low certainty evidence) had uncertain effects on hospitalisation for heart failure, as treatment estimates were consistent with either benefit or harm. Treatment with beta-blockers may decrease hospitalisation for heart failure (3 studies, 2287 participants: RR 0.67, 95% CI 0.43 to 1.05; I² = 87%; low certainty evidence). Aldosterone antagonists may increase the risk of hyperkalaemia compared to placebo or no treatment (3 studies, 826 participants: RR 2.91, 95% CI 2.03 to 4.17; I² = 0%; low certainty evidence). Renin inhibitors had uncertain risks of hyperkalaemia (2 studies, 142 participants: RR 0.86, 95% CI 0.49 to 1.49; I² = 0%; very low certainty). We were unable to estimate whether treatment with sinus node inhibitors affects the risk of hyperkalaemia, as there were few studies and meta-analysis was not possible. Hyperkalaemia was not reported for the CKD subgroup in studies investigating other therapies. The effects of ACEi or ARB, or aldosterone antagonists on worsening heart failure or kidney function, hypotension, or quality of life were uncertain due to sparse data or were not reported. Effects of anti-arrhythmic agents, digoxin, phosphodiesterase inhibitors, renin inhibitors, sinus node inhibitors, vasodilators, and vasopressin receptor antagonists were very uncertain due to the paucity of studies.

AUTHORS' CONCLUSIONS

The effects of pharmacological interventions for heart failure in people with CKD are uncertain and there is insufficient evidence to inform clinical practice. Study data for treatment outcomes in patients with heart failure and CKD are sparse despite the potential impact of kidney impairment on the benefits and harms of treatment. Future research aimed at analysing existing data in general population HF studies to explore the effect in subgroups of patients with CKD, considering stage of disease, may yield valuable insights for the management of people with HF and CKD.

Optimizing Hypertensive Acute Heart Failure Management with Afterload Reduction

PURPOSE OF REVIEW

In spite of advances in our understanding of acute heart failure (AHF) and its different phenotypic expressions, AHF management is still centered on volume removal with intravenous diuretics. This narrative review describes the pathophysiology underlying hypertensive AHF and appraises therapies targeting these mechanisms.

RECENT FINDINGS

Vascular redistribution rather than volume overload may be the primary determinant of elevated cardiac filling pressures and subsequent pulmonary congestion in patients with hypertensive AHF; in these patients, vasodilators should be the predominant treatment. Additional therapy with diuretics in hypertensive AHF should be relegated to the treatment of overt volume overload or persistent congestion in spite of optimized hemodynamics. Intravenous nitroglycerin at high doses can rapidly achieve pulmonary decongestion and reduce downstream critical care needs in these patients. The therapeutic role for synthetic peptides with vasodilator properties has yet to be defined. Evidence supporting both old and new vasodilator therapies is limited by a paucity of well-designed studies and failure to demonstrate improvement in long-term outcomes. Targeted study of this phenotype of AHF is needed before vasodilator therapies become incorporated into treatment guidelines.

Systolic blood pressure reduction during the first 24 h in acute heart failure admission: friend or foe?

AIMS

Changes in systolic blood pressure (SBP) during an admission for acute heart failure (AHF), especially those leading to hypotension, have been suggested to increase the risk for adverse outcomes.

METHODS AND RESULTS

We analysed associations of SBP decrease during the first 24 h from randomization with serum creatinine changes at the last time-point available (72 h), using linear regression, and with 30- and 180-day outcomes, using Cox regression, in 1257 patients in the VERITAS study. After multivariable adjustment for baseline SBP, greater SBP decrease at 24 h from randomization was associated with greater creatinine increase at 72 h and greater risk for 30-day all-cause death, worsening heart failure (HF) or HF readmission. The hazard ratio (HR) for each 1 mmHg decrease in SBP at 24 h for 30-day death, worsening HF or HF rehospitalization was 1.01 [95% confidence interval (CI) 1.00-1.02; P = 0.021]. Similarly, the HR for each 1 mmHg decrease in SBP at 24 h for 180-day all-cause mortality was 1.01 (95% CI 1.00-1.03; P = 0.038). The associations between SBP decrease and outcomes did not differ by tezosentan treatment group, although tezosentan treatment was associated with a greater SBP decrease at 24 h.

CONCLUSIONS

In the current post hoc analysis, SBP decrease during the first 24 h was associated with increased renal impairment and adverse outcomes at 30 and 180 days. Caution, with special attention to blood pressure monitoring, should be exercised when vasodilating agents are given to AHF patients.

Systolic Blood Pressure on Admission and Mortality in Patients Hospitalized With Acute Heart Failure: Observations From the Gulf Acute Heart Failure Registry

We investigated the role of systolic blood pressure (SBP) in relation to in-hospital and postdischarge mortality in patients admitted with acute heart failure (AHF). The SBP of 4848 patients aged ≥18 years admitted with AHF was categorized into 5 groups: ≤90, 91 to 119, 120 to 139, 140 to 161, and >161 mm Hg. After adjusting for several confounders, multivariate logistic regression models showed that admission SBP was a significant predictor of mortality among both patients with preserved left ventricular function (defined as left ventricular ejection fraction [LVEF] ≥40%) and patients with left ventricular dysfunction (LVEF <40%). The adjusted odds ratios of in-hospital, 3-month, and 1-year mortality in the lowest SBP groups were 7.06 (95% confidence interval [CI]: 3.28-15.20; P < .001), 2.59 (95% CI: 1.35-4.96; P = .004), and 3.10 (95% CI: 2.04-4.72; P < .001) times the odds in the highest admission group (SBP > 161 mm Hg), respectively. We conclude that low admission SBP is an independent predictor of mortality in patients with AHF. The higher the admission SBP, the better the prognosis, regardless of age or LVEF.

Development and validation of a risk model for in-hospital worsening heart failure from the Acute Decompensated Heart Failure National Registry (ADHERE)

BACKGROUND

A subset of patients hospitalized with acute heart failure experiences in-hospital worsening heart failure, defined as persistent or worsening signs or symptoms requiring an escalation of therapy.

METHODS

We analyzed data from the Acute Decompensated Heart Failure National Registry (ADHERE) linked to Medicare claims to develop and validate a risk model for in-hospital worsening heart failure. Our definition of in-hospital worsening heart failure included events such as escalation of medical therapy (eg, inotropic medications) >12hours after admission. We considered candidate risk prediction variables routinely assessed at admission, including age, medical history, biomarkers, and renal function. We used logistic regression with robust standard errors to generate a risk model in a 66% random derivation sample; we validated the model in the remaining 34%. We evaluated the calibration and discrimination of the model in both samples.

RESULTS

We evaluated 23,696 patients hospitalized with acute heart failure. Baseline characteristics were well matched in the derivation and validation samples, and the occurrence of in-hospital worsening heart failure was similar in both samples (15.4% and 15.6%, respectively). In the multivariable model, the strongest predictors of in-hospital worsening heart failure were increased troponin and creatinine. The model was well calibrated and had good discrimination in the derivation sample (c statistic, 0.74) and validation sample (c statistic, 0.72).

CONCLUSIONS

The ADHERE worsening heart failure risk model is a clinical tool with good discrimination for use in patients hospitalized with acute heart failure to identify those at increased risk for in-hospital worsening heart failure. This tool may be useful to target treatment strategies for patients at high risk for in-hospital worsening heart failure.

Clinical and Research Considerations for Patients With Hypertensive Acute Heart Failure: A Consensus Statement from the Society for Academic Emergency Medicine and the Heart Failure Society of America Acute Heart Failure Working Group

Management approaches for patients in the emergency department (ED) who present with acute heart failure (AHF) have largely focused on intravenous diuretics. Yet, the primary pathophysiologic derangement underlying AHF in many patients is not solely volume overload. Patients with hypertensive AHF (H-AHF) represent a clinical phenotype with distinct pathophysiologic mechanisms that result in elevated ventricular filling pressures. To optimize treatment response and minimize adverse events in this subgroup, we propose that clinical management be tailored to a conceptual model of disease that is based on these mechanisms. This consensus statement reviews the relevant pathophysiology, clinical characteristics, approach to therapy, and considerations for clinical trials in ED patients with H-AHF.

Worsening Heart Failure Following Admission for Acute Heart Failure: A Pooled Analysis of the PROTECT and RELAX-AHF Studies

OBJECTIVES

These studies conducted analyses to examine patient characteristics and outcomes associated with worsening heart failure (WHF).

BACKGROUND

WHF during an admission for acute heart failure (AHF) represents treatment failure and is a potential therapeutic target for clinical trials of AHF.

METHODS

Individual patient data from the PROTECT (Placebo-Controlled Randomized Study of the Selective A1 Adenosine Receptor Antagonist Rolofylline for Patients Hospitalized with Acute Decompensated Heart Failure and Volume Overload to Assess Treatment Effect on Congestion and Renal Function) and RELAX-AHF (Relaxin in Acute Heart Failure) phase II and III studies were pooled for analysis.

RESULTS

Of 3,691 patients, death or WHF through day 5 occurred in 12.4%, ranging from 9.5% to 14.5% among studies. A multivariable model provided modest discrimination between patients who did or did not develop WHF (C-index = 0.68). After multivariable adjustment, WHF was associated with a mean increase in length of stay of 5.2 days (95% confidence interval [CI]: 4.6 to 5.8 days) and increased risks of 60-day HF or renal failure readmission or cardiovascular death (hazard ratio [HR]: 1.64, 95% CI: 1.34 to 2.01) and 180-day mortality (HR: 1.93, 95% CI: 1.55 to 2.41) (all p < 0.001). The risk of mortality was higher in patients whose WHF required intravenous inotropes or mechanical therapy (HR: 3.03, 95% CI: 2.11 to 4.36) compared with patients whose WHF was treated with intravenous loop diuretic alone (HR: 1.80, 95% CI: 1.36 to 2.36) (both p < 0.001). WHF was associated with larger increases in markers of renal and hepatic dysfunction during the first days of admission, but remained significantly associated with adverse outcomes after adjustment for these changes.

CONCLUSIONS

WHF during the first 5 days of admission for AHF occurred in approximately 10% to 15% of patients and was associated with longer length of stay and higher risk for readmission and death.

Rationale and Design of the "Safety and Efficacy of the Combination of Loop with Thiazide-type Diuretics in Patients with Decompensated Heart Failure (CLOROTIC) Trial:" A Double-Blind, Randomized, Placebo-Controlled Study to Determine the Effect of Combined Diuretic Therapy (Loop Diuretics With Thiazide-Type Diuretics) Among Patients With Decompensated Heart Failure

BACKGROUND

Fluid overload refractory to loop diuretic therapy can complicate acute or chronic heart failure (HF) management. The Safety and Efficacy of the Combination of Loop with Thiazide-type Diuretics in Patients with Decompensated Heart Failure (CLOROTIC) trial (Clinicaltrials.gov identifier NCT01647932) will test the hypothesis that blocking distal tubule sodium reabsorption with hydrochlorothiazide can antagonize the renal adaptation to chronic loop diuretic therapy and improve diuretic resistance.

METHODS

CLOROTIC is a randomized, placebo-controlled, double-blind, multicenter study. Three hundred and four patients with decompensated HF will be randomly assigned to receive hydrochlorothiazide or placebo in addition to a furosemide regimen. The main inclusion criteria are: age ≥18 years, history of chronic HF (irrespective of etiology and/or ejection fraction), admission for acute decompensation, and previous treatment with an oral loop diuretic for at least 1 month before randomization. The 2 coprimary endpoints are changes in body weight and changes in patient-reported dyspnea during hospital admission. Morbidity, mortality, and safety aspects will also be addressed.

CONCLUSIONS

CLOROTIC is the first large-scale trial to evaluate whether the addition of a thiazide diuretic (hydrochlorothiazide) to a loop diuretic (furosemide) is a safe and effective strategy for improving congestive symptoms resulting from HF. This trial will provide important information and will therefore have a major impact on treatment strategies and future trials in these patients.

The Impact of Worsening Heart Failure in the United States

In-hospital worsening heart failure represents a clinical scenario wherein a patient hospitalized for acute heart failure experiences a worsening of their condition, requiring escalation of therapy. Worsening heart failure is associated with worse in-hospital and postdischarge outcomes. Worsening heart failure is increasingly being used as an endpoint or combined endpoint in clinical trials, as it is unique to episodes of acute heart failure and captures an important event during the inpatient course. While prediction models have been developed to identify worsening heart failure, there are no known FDA-approved medications associated with decreased worsening heart failure. Continued study is warranted.

Predictors of clinical outcomes in acute decompensated heart failure: Acute Study of Clinical Effectiveness of Nesiritide in Decompensated Heart Failure outcome models

BACKGROUND

Patients hospitalized for acute decompensated heart failure (ADHF) are at high risk for early mortality and rehospitalization. Risk stratification of ADHF using clinically available data on admission is increasingly important to integrate with clinical pathways. Our goal was to create a simple method of screening patients upon admission to identify those with increased risk of future adverse events.

METHODS

Using ASCEND-HF, a pragmatic clinical trial conducted in 398 sites globally, we developed and validated logistic regression risk models for (a) 30-day mortality/HF rehospitalization, (b) 30-day mortality/all-cause rehospitalization, (c) 30-day all-cause mortality, and (d) 180-day all-cause mortality. Fifty-one candidate variables were evaluated based on prior publications and clinical review. Final models were selected based on stepwise selection with entry and a staying criterion of P < .01. The 30-day mortality model was externally validated, and coefficients were converted to an additive risk score.

RESULTS

Among 7,141 patients, the median age was 67 years, 34% were female, and 80% had a left ventricular ejection fraction <40%. The models had between 5 and 12 risk factors with c-indices ranging from 0.68 to 0.75. A simplified score, including age, systolic blood pressure, sodium, blood urea nitrogen, and dyspnea at rest, discriminated 30-day mortality risk from 0.5% (score 0) to 53% (score 10).

CONCLUSIONS

Commonly available clinical variables provide simple risk stratification for clinical outcomes among patients with ADHF, and these models may be considered for integration into routine clinical care.

Assessment and prevalence of pulmonary oedema in contemporary acute heart failure trials: a systematic review

AIMS

Pulmonary oedema is a common and important finding in acute heart failure (AHF). We conducted a systematic review to describe the methods used to assess pulmonary oedema in recent randomized AHF trials and report its prevalence in these trials.

METHODS AND RESULTS

Of 23 AHF trials published between 2002 and 2013, six were excluded because they were very small or not randomized, or missing full-length publications. Of the remaining 17 (n = 200-7141) trials, six enrolled patients with HF and reduced ejection fraction (HF-REF) and 11, patients with both HF-REF and HF with preserved ejection fraction (HF-PEF). Pulmonary oedema was an essential inclusion criterion, in most trials, based upon findings on physical examination ('rales'), radiographic criteria ('signs of congestion'), or both. The prevalence of pulmonary oedema in HF-REF trials ranged from 75% to 83% and in combined HF-REF and HF-PEF trials from 51% to 100%. Five trials did not report the prevalence or extent of pulmonary oedema assessed by either clinical examination or chest x-ray. Improvement of pulmonary congestion with treatment was inconsistently reported and commonly grouped with other signs of congestion into a score. One trial suggested that patients with rales over >2/3 of the lung fields on admission were at higher risk of adverse outcomes than those without.

CONCLUSION

Although pulmonary oedema is a common finding in AHF, represents a therapeutic target, and may be of prognostic importance, recent trials used inconsistent criteria to define it, and did not consistently report its severity at baseline or its response to treatment. Consistent and ideally quantitative, methods for the assessment of pulmonary oedema in AHF trials are needed.

Agents with vasodilator properties in acute heart failure: how to design successful trials

Agents with vasodilator properties (AVDs) are frequently used in the treatment of acute heart failure (AHF). AVDs rapidly reduce preload and afterload, improve left ventricle to aorta and right ventricle to pulmonary artery coupling, and may improve symptoms. Early biomarker changes after AVD administration have suggested potentially beneficial effects on cardiac stretch, vascular tone, and renal function. AVDs that reduce haemodynamic congestion without causing hypoperfusion might be effective in preventing worsening organ dysfunction. Existing AVDs have been associated with different results on outcomes in randomized clinical trials, and observational studies have suggested that AVDs may be associated with a clinical outcome benefit. Lessons have been learned from past AVD trials in AHF regarding preventing hypotension, selecting the optimal endpoint, refining dyspnoea measurements, and achieving early randomization and treatment initiation. These lessons have been applied to the design of ongoing pivotal clinical trials, which aim to ascertain if AVDs improve clinical outcomes. The developing body of evidence suggests that AVDs may be a clinically effective therapy to reduce symptoms, but more importantly to prevent end-organ damage and improve clinical outcomes for specific patients with AHF. The results of ongoing trials will provide more clarity on the role of AVDs in the treatment of AHF.

Acute heart failure in the elderly: differences in clinical characteristics, outcomes, and prognostic factors in the VERITAS Study

BACKGROUND

Acute heart failure (HF) is common in the elderly, but the association of age with clinical outcomes and prognostic factors has not been examined thoroughly.

METHODS AND RESULTS

We analyzed the clinical and laboratory characteristics and the outcomes of 1,347 patients with acute HF enrolled in the VERITAS trial. Subjects were subdivided based on their median age of 72 years. Older patients had a higher prevalence of comorbidities and a higher prevalence of hypertension and atrial fibrillation. During a mean follow-up of 149 ± 61 days, 432 patients (32.1%) reached the composite end point of death, in-hospital worsening HF, or HF rehospitalization by 30 days, and 135 patients (10.4%) died by 90 days, with a worse outcome in elderly patients in both cases. At multivariable analysis, different variables were related with each of these outcomes in elderly compared with younger patients. Regarding deaths at 90 days, plasma urea nitrogen and hemoglobin levels were predictive only in the younger patients, whereas respiratory rate and albumin levels were associated with mortality only in the older patients.

CONCLUSIONS

Elderly patients with acute HF have different clinical characteristics and poorer outcomes. Prognostic variables differ in elderly compared with younger patients.

In-hospital worsening heart failure and associations with mortality, readmission, and healthcare utilization

BACKGROUND

A subset of patients hospitalized with acute heart failure experiences worsening clinical status and requires escalation of therapy. Worsening heart failure is an end point in many clinical trials, but little is known about its prevalence in clinical practice and its associated outcomes.

METHODS AND RESULTS

We analyzed inpatient data from the Acute Decompensated Heart Failure National Registry linked to Medicare claims to examine the prevalence and outcomes of patients with worsening heart failure, defined as the need for escalation of therapy at least 12 hours after hospital presentation. We compared patients with worsening heart failure to patients with an uncomplicated hospital course and patients with a complicated presentation. Of 63 727 patients hospitalized with acute heart failure, 11% developed worsening heart failure. These patients had the highest observed rates of mortality, all-cause readmission, and Medicare payments at 30 days and 1 year after hospitalization (P < 0.001 for all comparisons). The adjusted hazards of 30-day mortality were 2.56 (99% CI, 2.34 to 2.80) compared with an uncomplicated course and 1.29 (99% CI, 1.17 to 1.42) compared with a complicated presentation. The adjusted cost ratios for postdischarge Medicare payments at 30 days were 1.35 (99% CI, 1.24 to 1.46) compared with an uncomplicated course and 1.11 (99% CI, 1.02 to 1.22) compared with a complicated presentation.

CONCLUSIONS

In-hospital worsening heart failure was common and was associated with higher rates of mortality, all-cause readmission, and postdischarge Medicare payments. Prevention and treatment of in-hospital worsening heart failure represents an important goal for patients hospitalized with acute heart failure.

High prevalence of occult pulmonary venous hypertension revealed by fluid challenge in pulmonary hypertension

BACKGROUND

Determining the cause for pulmonary hypertension is difficult in many patients. Pulmonary arterial hypertension (PAH) is differentiated from pulmonary venous hypertension (PVH) by a wedge pressure (PWP)>15 mm Hg in PVH. Patients undergoing right heart catheterization for evaluation of pulmonary hypertension may be dehydrated and have reduced intravascular volume, potentially leading to a falsely low measurement of PWP and an erroneous diagnosis of PAH. We hypothesized that a fluid challenge during right heart catheterization would identify occult pulmonary venous hypertension (OPVH).

METHODS AND RESULTS

We reviewed the results of patients undergoing fluid challenge in our pulmonary hypertension database from 2004 to 2011. Baseline hemodynamics were obtained and repeated after infusion of 0.5 L of normal saline for 5 to 10 minutes. Patients were categorized as OPVH if PWP increased to >15 mm Hg after fluid challenge. Baseline hemodynamics in 207 patients met criteria for PAH. After fluid challenge, 46 patients (22.2%) developed a PWP>15 mm Hg and were reclassified as OPVH. Patients with OPVH had a greater increase in PWP compared with patients with PAH, P<0.001, and their demographics and comorbid illnesses were similar to patients with PVH. There were no adverse events related to fluid challenge.

CONCLUSIONS

Fluid challenge at the time of right heart catheterization is easily performed, safe, and identifies a large group of patients diagnosed initially with PAH, but for whom OPVH contributes to pulmonary hypertension. These results have implications for therapeutic trials in PAH and support the routine use of fluid challenge during right heart catheterization in patients with risk factors for PVH.

Evaluating Treatment Efficacy by Multiple End Points in Phase II Acute Heart Failure Clinical Trials

Background—

To assess concomitant simultaneous effects on multiple end points using global statistical methods in phase II acute heart failure studies.

Methods and Results—

Using simulations we have assessed different statistical methods to evaluate concomitant effects of a new intervention on dyspnea relief (using 2 measures), length of hospital stay, worsening heart failure to 5 days, mortality, and heart failure readmission to 30 days. Treatment effect scenarios included large (20% to 28% relative improvements) and very large (30% to 43% relative improvements) effects among others. Placebo responses and correlations among end points typical in recent acute heart failure clinical trials were used. Powers for the average Z score exceeded 70% with ≥75 patients per group for 35% relative improvement across all 6 end points. Assessing dyspnea alone generally provides lower power than the average Z score approach, with power deducted ≈50% under most of scenarios. Other approaches generally provide lower power than the average Z score method.

Conclusions—

Assessing the effects of new therapies on multiple clinical end points using the average Z score enables detection of therapeutic efficacy using sample sizes of 100 to 150 patients per group, approximately double the power achievable assessing the effects on dyspnea alone.

Contemporary management and research directions in advanced heart failure: where are we going?

Advanced heart failure (AHF) is not a uniform disorder, but is rather a heterogeneous group of patients with varying clinical presentations and definitions. It is growing in magnitude and represents a major public health problem. Herein we describe contemporary care of the patient with AHF, novel medical therapies, and mechanical circulatory assist devices. We speculate where progress has been made and where the major gaps in knowledge remain. Clearly, there is ample opportunity for research and discovery to further advance the care of these very sick patients.

A general inefficacy interim monitoring rule for randomized clinical trials

Background The ultimate goal of a phase III randomized clinical trial designed to demonstrate superiority of a new versus standard therapy is to provide sufficiently compelling evidence to affect clinical practice. To balance patient interests against the need for acquiring evidence it is desirable to stop a study for inefficacy as soon as convincing evidence that the new therapy is not beneficial becomes available.

Purpose To discuss potential deficiencies in some commonly used inefficacy monitoring rules and to propose a comprehensive inefficacy monitoring procedure.

Methods The proposed approach is developed using clinical, logistical, and statistical considerations. The new approach is compared to the commonly used inefficacy rules in a simulation study.

Results Some of the commonly used inefficacy rules are suboptimal with respect to the strength of evidence required for stopping throughout the trial: too conservative in the middle and/or too aggressive at the end. Our approach allows timely stopping (a) if the new therapy is harmful, and (b) if the interim data provides convincing evidence that the new therapy has no tangible benefit. Relative to common inefficacy rules, our procedure is shown to result in potentially fewer treated patients and shorter study duration under the null hypothesis with only a minor loss of power under the alternative hypothesis.

Limitations The proposed procedure is applicable to superiority designs with well-defined clinical objectives.

Conclusions The proposed inefficacy approach is attractive from statistical, clinical, and logistical standpoints. By decreasing average stopping times relative to the commonly used boundaries, our rule lessens patient exposure to inactive treatments, improves resource utilization, and accelerates dissemination of important clinical information. At the same time, the proposed rule provides a clear benchmark for providing compelling evidence that the new therapy is not beneficial. Clinical Trials 2010; 7: 197—208. http://ctj.sagepub.com

Early vasoactive drugs improve heart failure outcomes

Vasoactive therapy is often used to treat acute decompensated heart failure (ADHF). The authors sought to determine whether clinical outcomes are temporally associated with time to vasoactive therapy (vasoactive time) in ADHF. Using the Acute Decompensated Heart Failure (ADHERE) Registry, the authors examined the relationship between vasoactive time and inpatient mortality within 48 hours of hospitalization. Vasoactive agents were used early (defined as <6 hours) in 22,788 (63.8%) patients and late in 12,912 (36.2%). Median vasoactive time was 1.7 and 14.7 hours in the early and late groups, respectively. In-hospital mortality was significantly lower in the early group (odds ratio, 0.87; 95% confidence interval, 0.79-0.96; P=.006), and the adjusted odds of death increased 6.8% for every 6 hours of treatment delay (95% confidence interval, 4.2-9.6; P<.0001). Early vasoactive initiation is associated with improved outcomes in patients hospitalized for ADHF.

Myocardial protective effect of tezosentan, an endothelin receptor antagonist, for ischemia-reperfusion injury in experimental heart failure models

The myocardial protective effects of endothelin antagonist in ischemic cardiomyopathy (ICMP), doxorubicin-induced cardiomyopathy (DOX) and pressure-overload hypertrophy by transverse aortic constriction (TAC) models have been predicted to be different. The objective of this experiment, therefore, is to evaluate the myocardial protective effect of tezosentan, an endothelin receptor antagonist, in various experimental heart failure models. Sprague-Dawley rats (6-8 weeks old, 200-300 g) were randomized to three experimental groups (n=30 each): ICMP; DOX; and TAC group. Each of these groups was randomly assigned further to the following subgroups (n=10 each): sham-operated ischemia-reperfusion subgroup (SHAM); tezosentan treated ischemia-reperfusion subgroup (Tezo); and tezosentan non-treated ischemia-reperfusion subgroup (N-Tezo). Total circulatory arrest was induced for 1 hr, followed by 2 hr of reperfusion. The left ventricular developed pressure, peak positive and negative first derivatives, and coronary blood flow were significantly different (P<0.05) among the SHAM, Tezo, and N-Tezo subgroups of the ICMP group at 30 min of reperfusion, but there were no statistically significant differences among the subgroups of the DOX and TAC groups. In conclusion, tezosentan, an endothelin receptor antagonist, showed myocardial protection effects only on the ischemic cardiomyopathy rat model, but not in the non-ischemic heart failure rat models.

Vasodilators in the treatment of acute heart failure: what we know, what we don't

Although we have recently witnessed substantial progress in management and outcome of patients with chronic heart failure, acute heart failure (AHF) management and outcome have not changed over almost a generation. Vasodilators are one of the cornerstones of AHF management; however, to a large extent, none of those currently used has been examined by large, placebo-controlled, non-hemodynamic monitored, prospective randomized studies powered to assess the effects on outcomes, in addition to symptoms. In this article, we will discuss the role of vasodilators in AHF trying to point out which are the potentially best indications to their administration and which are the pitfalls which may be associated with their use. Unfortunately, most of this discussion is only partially evidence based due to lack of appropriate clinical trials. In general, we believe that vasodilators should be administered early to AHF patients with normal or high blood pressure (BP) at presentation. They should not be administered to patients with low BP since they may cause hypotension and hypoperfusion of vital organs, leading to renal and/or myocardial damage which may further worsen patients' outcome. It is not clear whether vasodilators have a role in either patients with borderline BP at presentation (i.e., low-normal) or beyond the first 1-2 days from presentation. Given the limitations of the currently available clinical trial data, we cannot recommend any specific agent as first line therapy, although nitrates in different formulations are still the most widely used in clinical practice.

Improvements in signs and symptoms during hospitalization for acute heart failure follow different patterns and depend on the measurement scales used: an international, prospective registry to evaluate the evolution of measures of disease severity in acute heart failure (MEASURE-AHF)

BACKGROUND

The natural evolution of signs and symptoms during acute heart failure (AHF) is poorly characterized.

METHODS AND RESULTS

We followed a prospective international cohort of 182 patients hospitalized with AHF. Patient-reported dyspnea and general well-being (GWB) were measured daily using 7-tier Likert (-3 to +3) and visual analog scales (VAS, 0-100). Physician assessments were also recorded daily. Mean age was 69 years and 68% had ejection fraction <40%. Likert measures of dyspnea initially improved rapidly (day 1, 0.22; day 2, 1.31; P <.001) with no significant improvement thereafter (day 7, 1.51; day 2 versus 7 P = .16). In contrast, VAS measure of dyspnea improved throughout hospitalization (day 1, 50.1; day 2, 64.7; day 7, 83.2; day 1 versus 2 P < .001, day 2 versus 7 P < .001). Symptoms of dyspnea and GWB tracked closely (correlation r = .813, P < .001). Physical signs resolved more completely than did symptoms (eg, from day 1 to discharge/day 7, absence of edema increased from 33% to 72% of patients, whereas significant improvements in dyspnea increased from 27% to 52% of patients; P < .001).

CONCLUSIONS

Changes in patient-reported symptoms and physician-assessed signs followed different patterns during an AHF episode and are influenced by the measurement scales used. Multiple clinical measures should be considered in discharge decisions and evaluation of AHF therapies.

New pharmacologic therapies for acute heart failure

Given the limitations of high-dose diuretics and vasodilators and the increasing literature showing that inotropes, regardless of the dose used, have a detrimental effect on mortality, a variety of new agents are under investigation for the treatment of pulmonary and systemic congestion and restoration of cardiac output in the setting of acute heart failure syndromes. The new therapeutic approach is based on two goals: short-term improvement in symptoms together with long-term improvement of cardiac function. This review describes new agents that are in preclinical and in clinical phases with realistic prospects: anti-endothelin, natriuretic peptides, istaroxime, levosimendan, myosin activators, and vasopressin antagonists. Those new therapeutic strategies aim to act at the cellular level to improve vessel and heart functions, with minimal side effects, together with improved sodium and water balance.

Reversal of isoproterenol-induced downregulation of phospholamban and FKBP12.6 by CPU0213-mediated antagonism of endothelin receptors

AIM

The downregulation of phospholamban (PLB) and FKBP12.6 as a result of beta- receptor activation is involved in the pathway(s) of congestive heart failure. We hypothesized that the endothelin (ET)-1 system may link to downregulated PLB and FKBP12.6.

METHODS

Rats were subjected to ischemia/reperfusion (I/R) to cause heart failure (HF). 1 mg/kg isoproterenol (ISO) was injected subcutaneously (sc) for 10 d to worsen HF. 30 mg/kg CPU0213 (sc), a dual ET receptor (ETAR/ETBR) antagonist was given from d 6 to d 10. On d 11, cardiac function was assessed together with the determination of mRNA levels of ryanodine receptor 2, calstabin-2 (FKBP12.6), PLB, and sarcoplasmic reticulum Ca2+-ATPase. Isolated adult rat ventricular myocytes were incubated with ISO at 1X10(-6) mol/L to set up an in vitro model of HF. Propranolol (PRO), CPU0213, and darusentan (DAR, an ETAR antagonist) were incubated with cardiomyocytes at 1X10(-5) mol/L or 1X10(-6) mol/L in the presence of ISO (1X10(-6) mol/L). Immunocytochemistry and Western blotting were applied for measuring the protein levels of PLB and FKBP12.6.

RESULTS

The worsened hemodynamics produced by I/R were exacerbated by ISO pretreatment. The significant downregulation of the gene expression of PLB and FKBP12.6 and worsened cardiac function by ISO were reversed by CPU0213. In vitro ISO 1X10(-6) mol/L produced a sharp decline of PLB and FKBP12.6 proteins relative to the control. The downregulation of the protein expression was significantly reversed by the ET receptor antagonist CPU0213 or DAR, comparable to that achieved by PRO.

CONCLUSION

This study demonstrates a role of ET in mediating the downregulation of the cardiac Ca2+-handling protein by ISO.

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.

Cardiac Transplantation: Any Role Left?

The authors analyze the question of whether heart transplantation still has a role in the current era of complex technologies. To achieve this objective, the authors first discuss the known benefits of different therapeutic modalities currently available for patients who have end-stage heart failure, including pharmacologic management, electrophysiologic therapies, high-risk surgical strategies, implantation of mechanical circulatory support device therapy, and heart transplantation. The authors then evaluate the current developments and future perspectives in the field that may influence the likelihood of heart transplantation to remain the therapeutic modality of choice for end-stage heart failure.

Selective Endothelin-A Receptor Inhibition After Cardiac Surgery: A Safety and Feasibility Study

BACKGROUND

Increased synthesis and release of the bioactive peptide endothelin has been shown to change hemodynamics and postoperative recovery after cardiac surgery. However, the clinical effects of selective interruption of endothelin signaling have not been studied. Because the endothelin-A (ET-A) receptor subtype is the primary cardiovascular effector for endothelin, this study used the ET-A receptor antagonist sitaxsentan sodium (TBC11251Na) to evaluate: (1) dose-dependent changes in pulmonary artery pressure (PAP) and pulmonary (PVRI) and systemic (SVRI) vascular resistance index in patients undergoing on-pump coronary revascularization; and (2) whether ET-RA administration was associated with increased adverse events.

METHODS

Patients (n = 44, age, 62 +/- 1 years) were randomized to receive vehicle (n = 9) or different bolus infusions of ET-A receptor antagonist: 0.1 (n = 9), 0.5 (n = 9) 1.0 (n = 9), and 2.0 mg/kg (n = 8) at separation from cardiopulmonary bypass (CPB). Adverse events were tabulated until hospital discharge. Results were expressed as changes from a composite baseline value, or from time 0 due to a high degree of intrapatient measurement variability in the postoperative period.

RESULTS

PAP increased by 27% +/- 13% from baseline (19 +/- 1 mm Hg) in the vehicle group at 6 hours post-CPB (p < 0.05). PAP fell from this post-CPB vehicle value in a dose-dependent manner with the ET-A receptor antagonist; with a significant reduction observed at 2 mg/kg (7% +/- 8% increase from baseline, p < 0.05). PVRI was reduced by 28.6% +/- 16% from baseline (249 +/- 22 dyn x s x cm(-5) x m(-2)) in the 2 mg/kg ET-A receptor antagonist group at 30 minutes post-CPB and remained reduced up to 6 hours post-CPB (p < 0.05). SVRI was reduced from baseline (2770 +/- 106 dyn x s x cm(-5) x m(-2)) by 51% +/- 6% in the 2.0 mg/kg ET-A receptor antagonist group at 30 minutes post-CPB (p < 0.05) and remained reduced up to 6 hours post-CPB. A total of 203 adverse events were tabulated in the postoperative period and were equally distributed across the five treatment groups, with no direct attributions to ET-A receptor antagonist treatment.

CONCLUSIONS

This unique study demonstrates that heightened endothelin-A receptor activation contributes to hemodynamic changes in patients after CPB. Selective inhibition of the endothelin receptor system can be successfully and safely performed in patients undergoing cardiac surgery and thereby reveals a potential, and clinically relevant therapeutic target.

Contrasting actions of endothelin ET(A) and ET(B) receptors in cardiovascular disease

First identified as a powerful vasoconstrictor, endothelin has an extremely diverse set of actions that influence homeostatic mechanisms throughout the body. Two receptor subtypes, ET(A) and ET(B), which usually have opposing actions, mediate the actions of endothelin. ET(A) receptors function to promote vasoconstriction, growth, and inflammation, whereas ET(B) receptors produce vasodilation, increases in sodium excretion, and inhibit growth and inflammation. Potent and selective receptor antagonists have been developed and have shown promising results in the treatment of cardiovascular diseases such as pulmonary arterial hypertension, acute and chronic heart failure, hypertension, renal failure, and atherosclerosis. However, results are often contradictory and complicated because of the tissue-specific vasoconstrictor actions of ET(B) receptors and the fact that endothelin is an autocrine and paracrine factor whose activity is difficult to measure in vivo. Considerable questions remain regarding whether ET(A)-selective or nonselective ET(A)/ET(B) receptor antagonists would be useful in a range of clinical settings.

Contrasting actions of endothelin ET(A) and ET(B) receptors in cardiovascular disease

First identified as a powerful vasoconstrictor, endothelin has an extremely diverse set of actions that influence homeostatic mechanisms throughout the body. Two receptor subtypes, ET(A) and ET(B), which usually have opposing actions, mediate the actions of endothelin. ET(A) receptors function to promote vasoconstriction, growth, and inflammation, whereas ET(B) receptors produce vasodilation, increases in sodium excretion, and inhibit growth and inflammation. Potent and selective receptor antagonists have been developed and have shown promising results in the treatment of cardiovascular diseases such as pulmonary arterial hypertension, acute and chronic heart failure, hypertension, renal failure, and atherosclerosis. However, results are often contradictory and complicated because of the tissue-specific vasoconstrictor actions of ET(B) receptors and the fact that endothelin is an autocrine and paracrine factor whose activity is difficult to measure in vivo. Considerable questions remain regarding whether ET(A)-selective or nonselective ET(A)/ET(B) receptor antagonists would be useful in a range of clinical settings.

Management of acute decompensated heart failure

Acute decompensated heart failure represents a heterogeneous group of disorders that typically present as dyspnea, edema and fatigue. Despite the high prevalence of this condition and its associated major morbidity and mortality, diagnosis can be difficult, and optimal treatment remains poorly defined. Identification of the acute triggers for the decompensation as well as noninvasive characterization of cardiac filling pressures and output is central to management. Diuretics, vasodilators, continuous positive airway pressure and inotropes can be used to alleviate symptoms. However, few agents currently available for the treatment of acute decompensated heart failure have been definitively shown in large prospective randomized clinical trials to provide meaningful improvements in intermediate-term clinical outcomes. Multiple novel therapies are being developed, but previous treatment failures indicate that progress in the management of acute decompensated heart failure is likely to be slow.

Canadian Cardiovascular Society Consensus Conference recommendations on heart failure update 2007: Prevention, management during intercurrent illness or acute decompensation, and use of biomarkers

Heart failure is common, yet it is difficult to treat. It presents in many different guises and circumstances in which therapy needs to be individualized. The Canadian Cardiovascular Society published a comprehensive set of recommendations in January 2006 on the diagnosis and management of heart failure, and the present update builds on those core recommendations. Based on feedback obtained through a national program of heart failure workshops during 2006, several topics were identified as priorities because of the challenges they pose to health care professionals. New evidence-based recommendations were developed using the structured approach for the review and assessment of evidence adopted and previously described by the Society. Specific recommendations and practical tips were written for the prevention of heart failure, the management of heart failure during intercurrent illness, the treatment of acute heart failure, and the current and future roles of biomarkers in heart failure care. Specific clinical questions that are addressed include: which patients should be identified as being at high risk of developing heart failure and which interventions should be used? What complications can occur in heart failure patients during an intercurrent illness, how should these patients be monitored and which medications may require a dose adjustment or discontinuation? What are the best therapeutic, both drug and nondrug, strategies for patients with acute heart failure? How can new biomarkers help in the treatment of heart failure, and when and how should BNP be measured in heart failure patients? The goals of the present update are to translate best evidence into practice, to apply clinical wisdom where evidence for specific strategies is weaker, and to aid physicians and other health care providers to optimally treat heart failure patients to result in a measurable impact on patient health and clinical outcomes in Canada.

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.

Ambrisentan, a Non-peptide Endothelin Receptor Antagonist

Increasing numbers of experimental investigations and recently also of clinical trials strongly suggest an integral involvement of the endothelin (ET)-system in the pathophysiology of a variety of disease states, mainly of the cardiovascular system. Ambrisentan (LU 208075), a selective ET(A)-receptor antagonist, is an orally active diphenyl propionic acid derivative. It has been shown to have a very promising efficacy to safety ratio in the initial clinical trials. Phase II and Phase III trials with ambrisentan in pulmonary arterial hypertension have been performed. The pharmacological properties and data from the experimental investigations suggest additional possible uses of ambrisentan in the prevention of reperfusion injury after organ transplantation and in restenosis following coronary artery dilatation. Furthermore, the pharmacological profile of ambrisentan indicates that this drug may also be suitable in the treatment of cerebrovascular disorders. In the present article basic investigations, animal studies and clinical trials with ambrisentan are reviewed. This review may help to define pathophysiological conditions, in which ambrisentan could be indicated and further evaluated in appropriate preclinical and clinical trials.

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.