Hemodynamic and clinical effects of tezosentan, an intravenous dual endothelin receptor antagonist, in patients hospitalized for acute decompensated heart failure

Vasodilators for Acute Heart Failure - A Systematic Review with Meta-Analysis

BACKGROUND

Acute heart failure is a public health concern. This study systematically reviewed randomized clinical trials (RCTs) to evaluate vasodilators in acute heart failure.

METHODS

The search was conducted across the databases of Medline, Embase, Latin American and the Caribbean Literature on Health Sciences, Web of Science, and the Cochrane Central Register of Controlled Trials. Inclusion criteria consisted of RCTs that compared vasodilators versus standard care, placebo, or cointerventions. The primary outcome was all-cause mortality; secondary outcomes were serious adverse events (SAEs), tracheal intubation, and length of hospital stay. Risk of bias was assessed in all trials.

RESULTS

The study included 46 RCTs that enrolled 28,374 patients with acute heart failure. Vasodilators did not reduce the risk of all-cause mortality (risk ratio, 0.95; 95% confidence interval [CI], 0.87 to 1.04; I2=9.51%; P=0.26). No evidence of a difference was seen in the risk of SAEs (risk ratio, 1.01; 95% CI, 0.97 to 1.05; I2=0.94%) or length of hospital stay (mean difference, -0.10; 95% CI, -0.28 to 0.08; I2=69.84%). Vasodilator use was associated with a lower risk of tracheal intubation (risk ratio, 0.54; 95% CI, 0.30 to 0.99; I2=51.96%) compared with no receipt of vasodilators.

CONCLUSIONS

In this systematic review with meta-analysis of patients with acute heart failure, vasodilators did not reduce all-cause mortality.

Efficacy of pharmacologic therapies in patients with acute heart failure: A network meta-analysis

Background: A network meta-analysis (NMA) of the current recommended drugs for the treatment of acute heart failure (AHF), was performed to compare the relative efficacy.

Methods: We used PubMed, EMBASE, Cochrane Clinical Trials Register, and Web of Science systems to search studies of randomized controlled trials (RCT) for the treatment of AHF recommended by the guidelines and expert consensus until 1 December 2020. The primary outcome was all-cause mortality within 30 days. The secondary outcomes included 30-days all-cause rehospitalization, rates of HF-related rehospitalization, rates of adverse events, and rates of serious adverse events. A Bayesian NMA based on random effects model was performed.

Results: After screening 14,888 citations, 23 RCTs (17,097 patients) were included, focusing on nesiritide, placebo, serelaxin, rhANP, omecamtiv mecarbil, tezosentan, KW-3902, conivaptan, tolvaptan, TRV027, chlorothiazide, metolazone, ularitide, relaxin, and rolofylline. Omecamtiv mecarbil had significantly lower all-cause mortality rates than the placebo (odds ratio 0.04, 0.01–0.22), rhANP (odds ratio 0.03, 0–0.40), serelaxin (odds ratio 0.05, 0.01–0.38), tezosentan (odds ratio 0.04, 0–0.22), tolvaptan (odds ratio 0.04, 0.01–0.30), and TRV027 (odds ratio 0.03, 0–0.36). No drug was superior to the other drugs for the secondary outcomes and safety outcomes.

Conclusion: No drug was superior to the other drugs for the secondary outcomes and safety outcomes. Current drugs for AHF show similar efficacy and safety.

Endothelin receptor antagonist improves donor lung function in an ex vivo perfusion system

BACKGROUND

A lung transplant is the last resort treatment for many patients with advanced lung disease. The majority of donated lungs come from donors following brain death (BD). The endothelin axis is upregulated in the blood and lung of the donor after BD resulting in systemic inflammation, lung damage and poor lung graft outcomes in the recipient. Tezosentan (endothelin receptor blocker) improves the pulmonary haemodynamic profile; however, it induces adverse effects on other organs at high doses. Application of ex vivo lung perfusion (EVLP) allows the development of organ-specific hormone resuscitation, to maximise and optimise the donor pool. Therefore, we investigate whether the combination of EVLP and tezosentan administration could improve the quality of donor lungs in a clinically relevant 6-h ovine model of brain stem death (BSD).

METHODS

After 6 h of BSD, lungs obtained from 12 sheep were divided into two groups, control and tezosentan-treated group, and cannulated for EVLP. The lungs were monitored for 6 h and lung perfusate and tissue samples were processed and analysed. Blood gas variables were measured in perfusate samples as well as total proteins and pro-inflammatory biomarkers, IL-6 and IL-8. Lung tissues were collected at the end of EVLP experiments for histology analysis and wet-dry weight ratio (a measure of oedema).

RESULTS

Our results showed a significant improvement in gas exchange [elevated partial pressure of oxygen (P = 0.02) and reduced partial pressure of carbon dioxide (P = 0.03)] in tezosentan-treated lungs compared to controls. However, the lungs hematoxylin-eosin staining histology results showed minimum lung injuries and there was no difference between both control and tezosentan-treated lungs. Similarly, IL-6 and IL-8 levels in lung perfusate showed no difference between control and tezosentan-treated lungs throughout the EVLP. Histological and tissue analysis showed a non-significant reduction in wet/dry weight ratio in tezosentan-treated lung tissues (P = 0.09) when compared to control.

CONCLUSIONS

These data indicate that administration of tezosentan could improve pulmonary gas exchange during EVLP.

Randomized double-blind clinical studies of ularitide and other vasoactive substances in acute decompensated heart failure: a systematic review and meta-analysis

AIMS

Acute decompensated heart failure (ADHF) has a poor prognosis and limited treatment options. No direct comparisons between ularitide-a synthetic natriuretic peptide being evaluated in ADHF-and other vasoactive substances are available. The aim of this meta-analysis was to determine haemodynamic effect sizes from randomized double-blind trials in ADHF.

METHODS AND RESULTS

Eligible studies enrolled patients with ADHF requiring hospitalization and haemodynamic monitoring. Patients received 24-48 h of infusion with a vasoactive substance or comparator. Primary outcome measure was pulmonary artery wedge pressure (PAWP). Treatment effects were quantified as changes from baseline using mean differences between study drug and comparator. Results were analysed using random-effects (primary analysis) and fixed-effects meta-analyses. Twelve randomized, double-blind studies were identified with data after 3, 6, and 24 h of treatment (n = 622, 644, and 644, respectively). At 6 h, significant PAWP benefits for ularitide over placebo were seen (Hedges' g effect size, -0.979; P < 0.0001). On meta-analysis, treatment difference between ularitide and pooled other agents was statistically significant (-0.501; P = 0.0303). Effect sizes were numerically higher with ularitide than other treatments at 3 and 24 h. After 6 h, a significant difference in effect size between ularitide and all other treatments was observed for right atrial pressure (Hedges' g, -0.797 for ularitide and -0.304 for other treatments; P = 0.0274).

CONCLUSIONS

After 6 h, ularitide demonstrated high effect sizes for PAWP and right atrial pressure. Improvements in these parameters were greater with ularitide vs. pooled data for other vasoactive drugs.

Pulmonary hypertension due to left heart disease causes intrapulmonary venous arterialization in rats

OBJECTIVE

A rat model of left atrial stenosis-associated pulmonary hypertension due to left heart diseases was prepared to elucidate its mechanism.

METHODS

Five-week-old Sprague-Dawley rats were randomly divided into 2 groups: left atrial stenosis and sham-operated control. Echocardiography was performed 2, 4, 6, and 10 weeks after surgery, and cardiac catheterization and organ excision were subsequently performed at 10 weeks after surgery.

RESULTS

Left ventricular inflow velocity, measured by echocardiography, significantly increased in the left atrial stenosis group compared with that in the sham-operated control group (2.2 m/s, interquartile range [IQR], 1.9-2.2 and 1.1 m/s, IQR, 1.1-1.2, P < .01), and the right ventricular pressure-to-left ventricular systolic pressure ratio significantly increased in the left atrial stenosis group compared with the sham-operated control group (0.52, IQR, 0.54-0.60 and 0.22, IQR, 0.15-0.27, P < .01). The right ventricular weight divided by body weight was significantly greater in the left atrial stenosis group than in the sham-operated control group (0.54 mg/g, IQR, 0.50-0.59 and 0.39 mg/g, IQR, 0.38-0.43, P < .01). Histologic examination revealed medial hypertrophy of the pulmonary vein was thickened by 1.6 times in the left atrial stenosis group compared with the sham-operated control group. DNA microarray analysis and real-time polymerase chain reaction revealed that transforming growth factor-β mRNA was significantly elevated in the left atrial stenosis group. The protein levels of transforming growth factor-β and endothelin-1 were increased in the lung of the left atrial stenosis group by Western blot analyses.

CONCLUSIONS

We successfully established a novel, feasible rat model of pulmonary hypertension due to left heart diseases by generating left atrial stenosis. Although pulmonary hypertension was moderate, the pulmonary hypertension due to left heart diseases model rats demonstrated characteristic intrapulmonary venous arterialization and should be used to further investigate the mechanism of pulmonary hypertension due to left heart diseases.

Clinical and Hemodynamic Effects of Endothelin Receptor Antagonists in Patients With Heart Failure

The clinical benefit of endothelin receptor antagonists (ERA) for the management of heart failure (HF) remains controversial. To examine this question, we performed a meta-analysis of randomized controlled trials (RCTs) to investigate the clinical and hemodynamic effects of ERA in HF patients.We searched the PubMed, Medline, Embase, and Cochrane Library from inception to March 20, 2016 to identify the pertinent studies. Risk ratio (RR) and weighted mean difference (WMD) were calculated using a fixed or random effect model.A total of 15 RCTs with 3,624 HF patients were included. Compared with control groups, ERA might not improve the mortality (RR 1.12, 95%CI 0.81 to 1.54, P = 0.51) or incidence of worsening HF or cardiovascular events (WHF/ CVE) (RR 1.06, 95%CI 0.94 to 1.19, P = 0.35) in HF patients. Subgroup analysis also suggested that neither nonselective nor selective ERAs had an impact on mortality and WHF/CVE. However, the hemodynamic variables of HF patients, including cardiac index (WMD 0.32, 95%CI 0.22 to 0.43, P < 0.01), pulmonary capillary wedge pressure (WMD -3.10, 95%CI -3.99 to -2.20, P < 0.01), mean pulmonary arterial pressure (WMD -4.42, 95%CI -5.50 to -3.33, P < 0.01), systemic vascular resistance (WMD -276.35, 95%CI -399.62 to -153.09, P < 0.01), and pulmonary vascular resistance (WMD -69.42, 95%CI -105.33 to -33.52, P < 0.01) were significantly improved by ERA.In conclusion, this meta-analysis suggests that ERA therapy could effectively improve cardiac output and pulmonary and systemic hemodynamics, but with less benefit to the clinical outcomes of HF patients.

Endothelin receptor antagonists for persistent pulmonary hypertension in term and late preterm infants

BACKGROUND

Endothelin, a powerful vasoconstrictor, is one of the mediators in the causation of persistent pulmonary hypertension of the newborn (PPHN). Theoretically, endothelin receptor antagonists (ETRA) have the potential to improve the outcomes of infants with PPHN.

OBJECTIVES

To assess the efficacy and safety of ETRA in the treatment of PPHN in full-term, post-term and late preterm infants.To assess the efficacy and safety of selective ETRAs (which block only the ETA receptors) and non-selective ETRAs (which block both ETA and ETB receptors) separately.

SEARCH METHODS

CENTRAL (Cochrane Central Register of Controlled Trials), MEDLINE, EMBASE and CINAHL databases were searched until December 2015.

SELECTION CRITERIA

Randomised, cluster-randomised or quasi-randomised controlled trials were eligible.

DATA COLLECTION AND ANALYSIS

Two review authors independently searched the literature, selected the studies, assessed the risk of bias and extracted the data. A fixed-effect model was used for meta-analysis. We used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to assess the quality of evidence.

MAIN RESULTS

Two randomised controlled trials of ETRA met the inclusion criteria. Both studies utilized oral Bosentan. The first study was done in a setting where inhaled nitric oxide (iNO) therapy was not available. Forty-seven infants (≥ 34 weeks' gestation) were randomised to receive either Bosentan or placebo. The second study was a multicentre study where iNO therapy was the standard of care for PPHN. Twenty-one infants were randomised to receive either 'iNO plus Bosentan' or 'iNO plus placebo'.In the first study, there was no significant difference in the incidence of death before hospital discharge between the Bosentan and placebo groups (1/23 vs 3/14; RR 0.20, 95% CI 0.02 to 1.77; RD -0.17, 95% CI -0.40 to 0.06). A higher proportion of infants in the Bosentan group showed improvement in oxygenation index (OI) at the end of therapy (21/24 vs 3/15; RR 4.38, 95% CI 1.57 to 12.17; RD 0.68, 95% CI 0.43 to 0.92; number needed to treat for a beneficial outcome (NNTB) 1.5). The duration of mechanical ventilation was lower in the Bosentan group (4.3 ± 0.9 vs 11.5 ± 0.6 days; MD -7.20, 95% CI -7.64 to -6.76). There was no significant difference in adverse neurological outcomes at six months (0/23 vs 4/14; RR 0.07, 95% CI 0.00 to 1.20; RD -0.29, 95% CI -0.52 to -0.05). The study suffered from a high risk of attrition bias since 8/23 infants in the placebo group were excluded from various analyses. Since the protocol for the study could not be accessed, the study suffered from unclear risk of reporting bias.In the second study, there was no significant difference in the incidence of treatment failure needing extracorporeal membrane oxygenation (ECMO) between the 'iNO plus Bosentan' vs 'iNO plus placebo' groups (1/13 vs 0/8; RR 1.93, 95% CI 0.09 to 42.35; RD 0.08, 95% CI -0.14 to 0.30). There was no significant difference in the median time to wean from iNO ('iNO plus Bosentan': 3.7 days (95% CI 1.17 to 6.95); 'iNO plus placebo': 2.9 days (95% CI 1.26 to 4.23); P = 0.34). There were no significant differences in the OI 0, 3, 5, 12, 24, 48 and 72 hours of treatment between the groups. There were no significant differences in the time to complete weaning from mechanical ventilation (median 10.8 days (CI 3.21 to 12.21) versus 8.6 days (CI 3.71 to 9.66); P = 0.24). The study had unequal distribution to the Bosentan group (N = 13) and the placebo group (N = 8). The methods used for generating random sequence numbers and allocation concealment were unclear, resulting in unclear risk of selection bias.Both studies reported that Bosentan was well tolerated and no major adverse effects were noted. Data from the two studies was not pooled given the heterogenous nature of the clinical settings and the modalities used for the treatment of PPHN.Overall, the quality of evidence was considered low, given the small sample size of the included studies, the numerical imbalance between the groups due to randomisation and attrition, and unclear risk of bias on some of the important domains.

AUTHORS' CONCLUSIONS

There is inadequate evidence to support the use of ETRAs either as stand-alone therapy or as adjuvant to inhaled nitric oxide in PPHN. Adequately powered RCTs are needed.

Similar hemodynamic decongestion with vasodilators and inotropes: systematic review, meta-analysis, and meta-regression of 35 studies on acute heart failure

BACKGROUND

Acute heart failure (AHF) with reduced left-ventricular ejection fraction (LVEF) is often a biventricular congested state. The comparative effect of vasodilators and inotropes on the right- and/or left-sided congestion is unknown.

METHODS AND RESULTS

A systematic review, meta-analysis, and meta-regression of AHF studies using pulmonary artery catheter were performed using PubMed, Embase, and Cochrane library. Data from 35 studies, including 3016 patients, were studied. Included patients had a weighted mean age of 60 years, left-ventricular ejection fraction (LVEF) of 24 %, and plasma B-type natriuretic peptide (BNP) of 892 pg/ml. Both the left- and right-ventricular filling pressures were elevated: weighted mean pulmonary artery wedge pressure (PAWP) was 25 mmHg (range 17-31 mmHg) and right atrial pressure (RAP) 12 mmHg (range 7-18 mmHg). Vasodilators and inotropes had similar beneficial effects on PAWP [-6.3 mmHg (95 % CI -7.4 to -5.2 mmHg) and -5.8 mmHg (95 % CI -7.6 to -4.0 mmHg), respectively] and RAP [-2.9 mmHg (95 % CI -3.8 to -2.1 mmHg) and -2.8 mmHg (95 % CI -3.8 to -1.7 mmHg), respectively]. Among inotropes, inodilators, such as levosimendan, have greater beneficial effect on the left-ventricular filling pressure than dobutamine. Drug-induced improvement of PAWP tightly paralleled that of RAP with all studied drugs (r ² = 0.90, p < 0.001). Vasodilators and inotropes had no short-term effect of renal function.

CONCLUSION

The left- and right-sided filling pressures are similarly improved by vasodilators or inotropes, in AHF with reduced LVEF.

Increased mortality with elevated plasma endothelin-1 in acute heart failure: an ASCEND-HF biomarker substudy

AIMS

Endothelin-1 (ET-1) is an endogenous vasoconstrictor implicated in pulmonary and systemic hypertension, as well as ventricular dysfunction, through effects on vascular smooth muscle, the kidneys, and cardiomyocytes. We aimed to determine the association between serial ET-1 levels and acute heart failure patient outcomes.

METHODS AND RESULTS

We measured plasma ET-1 at baseline, 48-72 h, and 30 days in a cohort of 872 patients hospitalized with acute heart failure from the ASCEND-HF trial (randomized to nesiritide vs. placebo), and its association with 30-day mortality, 180-day mortality, in-hospital death or worsening heart failure, and 30-day mortality or rehospitalization. Median ET-1 was 7.6 [interquartile range (IQR) 5.9-10] pg/mL at baseline, 6.3 (IQR 4.9-8.1) pg/mL at 48-72 h, and 5.9 (IQR 4.7-7.9) pg/mL at 30 days (P < 0.001). Baseline and 48-72 h ET-1 were found to be independently associated with 180-day mortality in a multivariable analysis [hazard ratio (HR) 1.6, 95% confidence interval (CI) 1.3-2.0, P < 0.001 and HR 1.5, 95% CI 1.2-1.9, P = 0.001, respectively, log-transformed]. ET-1 that was measured at 48-72 h was also independently associated with death or worsening heart failure prior to discharge [odds ratio (OR) 1.6, 95% CI 1.03-2.4, P = 0.03]. These independent associations remained significant after including NT-proBNP in the multivariable analysis.

CONCLUSIONS

We observed an independent association between elevated ET-1 and short-term in-hospital clinical outcomes and 180-day mortality in hospitalized patients with acute heart failure ET-1 provided additional prognostic information which was incremental to that yielded by NT-proBNP.

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.

Impact of the DASH diet on endothelial function, exercise capacity, and quality of life in patients with heart failure

Endothelial dysfunction has been recognized as a pathophysiologic mechanism in the progression of heart failure (HF). However, little attention has been given to the ability of dietary approaches to improve endothelial function. This study examined the effects of the Dietary Approaches to Stop Hypertension (DASH) diet on endothelial function, exercise capacity, and quality of life in patients with chronic symptomatic (stage C) HF. Forty-eight patients were randomized to follow the DASH diet (n = 24) or the general HF dietary recommendations (n = 24). Endothelial function was assessed by measuring large and small arterial elasticity (LAE and SAE) at rest. Exercise capacity (measured with the 6-minute walk test) and quality of life (measured with the Minnesota Living with Heart Failure Questionnaire) at baseline and 3 months were also evaluated. Patients were older adults with an average HF duration of 5 years. LAE at 1 month improved significantly in the DASH diet group (P < 0.01). Overall LAE and SAE scores at 3 months also improved; however, the net changes were not statistically significant. The DASH group had better exercise capacity (292 m vs 197 m; P = 0.018) and quality of life scores (21 vs 39; P = 0.006) over time, while sodium intake levels at 1, 2, and 3 months were comparable between the groups. Adhering to the DASH diet improved arterial compliance initially and improved exercise capacity and quality of life scores at 3 months. The DASH diet may be an important adjunctive therapy for patients with symptomatic HF.

Increased mortality after an acute heart failure episode: new pathophysiological insights from the RELAX-AHF study and beyond

Acute heart failure (AHF) is one of the most common causes of hospital admission. Despite the very high short-term morbidity and mortality and high costs associated with the condition, little progress has been made toward an understanding of the complex mechanisms of AHF, and particularly the spike in mortality after AHF admission. This manuscript addresses certain hypotheses for the pathophysiology of increased mortality after an AHF episode, specifically exploring the role of neurohormonal and inflammatory activation, congestion, and end-organ damage occurring during the first hours and days of an AHF episode. The results of the recently published RELAX-AHF (Relaxin in Acute Heart Failure) study may hold the key to understanding these intricate mechanisms. In the study, congestion and end-organ damage, which were strongly associated with increased 180-day mortality, were relieved by early administration of serelaxin, which was also associated with reduction in 180-day mortality. Hence, it is possible that early treatment of AHF, including decongestion and prevention of damage to end organs, including kidneys, heart, and liver, is critical to preventing mortality in AHF. This may require a change in our strategic approach to the management of patients admitted with AHF, setting them apart from patients with chronic heart failure (HF), and developing specific treatment strategies for AHF patients beyond simply implementing therapies proven to be effective in chronic HF.

Endothelin ETA receptor antagonism in cardiovascular disease

Since the discovery of the endothelin system in 1988, it has been implicated in numerous physiological and pathological phenomena. In the cardiovascular system, endothelin-1 (ET-1) acts through intracellular pathways of two endothelin receptors (ETA and ETB) located mainly on smooth muscle and endothelial cells to regulate vascular tone and provoke mitogenic and proinflammatory reactions. The endothelin ETA receptor is believed to play a pivotal role in the pathogenesis of several cardiovascular disease including systemic hypertension, pulmonary arterial hypertension (PAH), dilated cardiomyopathy, and diabetic microvascular dysfunction. Growing evidence from recent experimental and clinical studies indicates that the blockade of endothelin receptors, particularly the ETA subtype, grasps promise in the treatment of major cardiovascular pathologies. The simultaneous blockade of endothelin ETB receptors might not be advantageous, leading possibly to vasoconstriction and salt and water retentions. This review summarizes the role of ET-1 in cardiovascular modulation and the therapeutic potential of endothelin receptor antagonism.

[Endothelin: From discovery to pharmacotherapeutic innovations]

OBJECTIVES

Endothelin (ET) is a major therapeutic target in cardiopulmonary diseases. The purpose of this review is to present the main concepts concerning ET biology, its pathophysiological roles and the major pharmacological and medical advances recently developed around the concept of ET receptor blockade.

METHODS

Analysis of PubMed database (keywords: endothelin, endothelin receptor antagonists, pulmonary hypertension, etc.), and of abstract originating from recent international meetings.

RESULTS

ET is a peptide produced by vascular endothelial cells as well as by many other tissues. Both its production and its effects are activated in pathological situations associated with endothelial dysfunction. ET is characterized by a strong tropism toward tissues because of its polarized release, the strong tissue receptor density and high affinity of the receptors for the peptide. ET exerts several vascular effects, including vasoconstriction, proliferation and hypertrophy, as well as non-vascular effects, notably stimulation of cardiac hypertrophy, tissue fibrosis and inflammation. Both vascular and non-vascular effects depend on the stimulation of two receptor subtypes, ETA and ETB. ET receptor antagonists (ERA) demonstrated beneficial effects in many different pre-clinical models of cardiovascular and pulmonary diseases, and constitute a first-line treatment of patients with pulmonary arterial hypertension (PAH). Recently, the targeted search for a novel ERA led to the development of macitentan which, compared to existing ERA, show optimized tissue penetration, increased receptor affinity and in vivo pharmacological efficacy in pre-clinical models, associated with a favorable profile, in terms of hepatic safety and drug interactions. The clinical efficacy of macitentan in the treatment of PAH was recently demonstrated in the SERAPHIN trial, which contrasts with previous PAH trials because of its long duration, the high number of patients enrolled, and its primary endpoint evaluating morbidity/mortality. Results show a significant reduction of the primary composite morbidity/mortality endpoint (taking into account both progression of PAH and death) by 30 and 45% with macitentan 3 and 10mg, respectively, compared to placebo, and confirm on the large scale the favorable tolerance profile, especially at the hepatic level.

CONCLUSION

The extensive knowledge on the complexity of the ET system allowed the synthesis of a new antagonist optimized, in terms of pharmacological efficacy and safety, which also show promising therapeutic effects in PAH patients, with demonstrated results in a prospective study using a composite primary endpoint of morbidity-mortality.

Pulmonary hypertension due to left heart disease: updated Recommendations of the Cologne Consensus Conference 2011

The 2009 European Guidelines on Diagnosis and Treatment of Pulmonary Hypertension (PH) have been adopted for Germany. While the guidelines contain detailed recommendations regarding pulmonary arterial hypertension (PAH), they contain only a relatively short paragraph on other, much more frequent forms of PH including PH owing to left heart disease. The guidelines point out that the drugs currently used to treat patients with PAH (prostanoids, endothelin receptor antagonists and phosphodiesterase type 5 inhibitors) have not been sufficiently investigated in other forms of PH. However, despite the lack of respective efficacy data an uncritical use of targeted PAH drugs in patients with PH associated with left heart disease is currently observed at an increasing rate. This development is a matter of concern. On the other hand, PH is a frequent problem that is highly relevant for morbidity and mortality in patients with left heart disease. It that sense, the practical implementation of the European Guidelines in Germany requires the consideration of several specific issues and already existing novel data. This requires a detailed commentary to the guidelines, and in some aspects an update already appears necessary. In June 2010, a Consensus Conference organized by the PH working groups of the German Society of Cardiology (DGK), the German Society of Respiratory Medicine (DGP) and the German Society of Pediatric Cardiology (DGPK) was held in Cologne, Germany. This conference aimed to solve practical and controversial issues surrounding the implementation of the European Guidelines in Germany. To this end, a number of working groups was initiated, one of which was specifically dedicated to PH due to left heart disease. This commentary describes in detail the results and recommendations of the working group which were last updated in October 2011.

Pathophysiological roles of endothelin receptors in cardiovascular diseases

Endothelin (ET)-1 derived from endothelial cells has a much more important role in cardiovascular system regulation than the ET-2 and ET-3 isoforms. Numerous lines of evidence indicate that ET-1 possesses a number of biological activities leading to cardiovascular diseases (CVD) including hypertension and atherosclerosis. Physiological and pathophysiological responses to ET-1 in various tissues are mediated by interactions with ET(A)- and ET(B)-receptor subtypes. Both subtypes on vascular smooth muscle cells mediate vasoconstriction, whereas the ET(B)-receptor subtype on endothelial cells contributes to vasodilatation and ET-1 clearance. Although selective ET(A)- or nonselective ET(A)/ET(B)-receptor antagonisms have been assumed as potential strategies for the treatment of several CVD based on clinical and animal experiments, it remains unclear which antagonisms are suitable for individuals with CVD because upregulation of the nitric oxide system via the ET(B) receptor is responsible for vasoprotective effects such as vasodilatation and anti-cell proliferation. In this review, we have summarized the current understanding regarding the role of ET receptors, especially the ET(B) receptor, in CVD.

Cinaciguat, a soluble guanylate cyclase activator: results from the randomized, controlled, phase IIb COMPOSE programme in acute heart failure syndromes

AIMS

Cinaciguat (BAY 58-2667) is a soluble guanylate cyclase (sGC) activator that, in a previous study among patients with acute heart failure syndromes (AHFS), improved pulmonary capillary wedge pressure (PCWP) at the expense of significant hypotension at doses ≥200 µg/h. The aim of the COMPOSE programme was to investigate the safety and efficacy of fixed, low doses of intravenous cinaciguat (<200 µg/h for 24-48 h) as add-on to standard therapy in adults hospitalized with AHFS.

METHODS AND RESULTS

COMPOSE comprised three randomized, double-blind, placebo-controlled studies in patients with [COMPOSE 1 and 2 (NCT01065077 and NCT01067859)] or without [COMPOSE EARLY (NCT01064037)] a requirement for invasive haemodynamic monitoring. COMPOSE 1 and COMPOSE EARLY assessed the effects of cinaciguat (50, 100, and 150 µg/h) on haemodynamics and dyspnoea, respectively. COMPOSE 2 assessed the haemodynamic effects of 10 and 25 µg/h cinaciguat. COMPOSE was terminated early due to an excess of non-fatal hypotension and recruitment difficulties. In COMPOSE 1 (n = 12), cinaciguat reduced PCWP at 8 h compared with placebo, but there was no relevant change in cardiac index. In COMPOSE EARLY (n = 62), no meaningful difference in dyspnoea was shown between cinaciguat and placebo.

CONCLUSION

In this limited database, short-term use of intravenous cinaciguat decreased blood pressure without improving dyspnoea or cardiac index. Given the lack of effect on dyspnoea and cardiac index and the hypotensive effect seen even with low doses, it is doubtful that further studies with intravenous cinaciguat would prove beneficial in this patient population.

Acute heart failure: lessons learned so far

Acute heart failure (AHF) affects nearly every Canadian with heart failure (HF) at least once. Despite several attempts, no medical therapies have been shown to improve the natural history of AHF. In addition, the place of diagnosis of AHF is increasingly made in the outpatient setting. In this view, AHF is a moving target, and from recent registry data and from clinical trials, 5 critical lessons regarding the syndrome of AHF emerge: (1) The period of clinical instability preceding AHF may be much longer than previously thought. (2) Refinement of tools used to aid the early and accurate diagnosis of AHF will impact patient outcomes. (3) Standard supportive care of patients with AHF includes early use of diuretics with frequent reassessment in nearly all patients and supplemental vasodilators and oxygen therapy in selected cases. (4) Patients who survive presentation of AHF continue to suffer high rates of re-presentation, death, and rehospitalization following discharge from either hospital or emergency department. (5) Interventions shown to improve patient outcomes for AHF to date are related to process of care rather than new medications or devices. This report reviews the recent literature regarding the presentation, diagnosis, management, and prognosis of AHF. Areas of future research priority are indicated and guidelines for improving treatment are provided. AHF is an important clinical area that has not been as intensively studied as chronic HF; it presents both important needs and exciting opportunities for research and innovation.

Clinical development of pharmacologic agents for acute heart failure syndromes: a proposal for a mechanistic translational phase

Hospitalization for acute heart failure syndromes (AHFS) predicts a poor prognosis, with postdischarge mortality and rehospitalization rates reaching 45% within 60 to 90 days. Despite the use of evidence-based therapies and adherence to national process measures, these event rates have largely remained the same over the past decade. Given the current and growing burden of AHFS, there exists a substantial unmet need for novel therapies that improve outcomes. However, attempts to improve symptoms and/or reduce postdischarge events have failed to produce positive results, either because of safety and/or efficacy. These negative results may be related to the drug itself, the protocol in terms of patient selection and/or end points, and/or the trial execution. Although experts may not agree on the exact reasons to explain the lack of success to date of phase III trials in AHFS, there is agreement that clinical benefits observed in phase II trials were not reproduced in phase III trials. A different approach may be needed. In November of 2009, a meeting was held at the Food and Drug Administration with the primary purpose of identifying the reasons why benefits observed during phase II did not translate into benefits in phase III to improve future trial design. Although multiple domains of trial design were discussed, the participants identified a lack of in-depth understanding of novel molecules before pivotal trials in AHFS as a possible contributor to the disappointing results of recent large trials. In this brief report, we outline the T1 or translational phase of research for AHFS clinical development as an important first step toward greater success in AHFS clinical trials.

Endothelin

Endothelin-1 is the most potent vasoconstrictor agent currently identified, and it was originally isolated and characterized from the culture media of aortic endothelial cells. Two other isoforms, termed endothelin-2 and endothelin-3, were subsequently identified, along with structural homologues isolated from the venom of Actractapis engaddensis known as the sarafotoxins. In this review, we will discuss the basic science of endothelins, endothelin-converting enzymes, and endothelin receptors. Only concise background information pertinent to clinical physician is provided. Next we will describe the pathophysiological roles of endothelin-1 in pulmonary arterial hypertension, heart failure, systemic hypertension, and female malignancies, with emphasis on ovarian cancer. The potential intervention with pharmacological therapeutics will be succinctly summarized to highlight the exciting pre-clinical and clinical studies within the endothelin field. Of note is the rapid development of selective endothelin receptor antagonists, which has led to an explosion of research in the field.

A review of dyspnea in acute heart failure syndromes

In acute heart failure syndrome (AHFS), dyspnea is one of the most common but least understood presenting symptoms for hospitalization. For this reason, dyspnea relief is increasingly becoming a focus in the development of therapies for the treatment of AHFS, and currently stands as an acceptable primary end point for regulatory approval by governmental agencies. This raises the question of how best to measure such a subjective symptom. In this review, we will describe the basis for dyspnea, provide a detailed description of the strengths and weaknesses of the current best tools used to measure it, and describe future directions for future development of dyspnea measurement in AHFS.

The right heart and pulmonary circulation (III). The pulmonary circulation in heart failure

Pulmonary hypertension due to left heart disease is a pathophysiological and hemodynamic state which is present in a wide range of clinical conditions that affect left heart structures. Although the pulmonary circulation has traditionally received little attention, it is reasonable to say that today it is a fundamental part of cardiological evaluation. In patients with heart failure, the most important clinical factors are the presence of pulmonary hypertension and right ventricular function. These factors are also essential for determining prognosis and must be taken into account when making some of the most important therapeutic decisions. The pathophysiological process starts passively but later transforms into a reactive process. This latter process, in turn, has one component that can be reversed with vasodilators and another component that is fixed, in which the underlying mechanism is congestive vasculopathy (i.e. essentially medial hypertrophy and pulmonary arterial intimal fibrosis). Currently no specific therapy is available for this type of pulmonary hypertension and treatment is the same as for heart failure itself. The drugs that have been shown to be effective in pulmonary arterial hypertension have generally had a neutral effect in clinical trials. Nevertheless, we are involved in the clinical development of a number of groups of pharmacological compounds that will enable us to make progress in the near future.

Flash pulmonary edema

Flash pulmonary edema (FPE) is a general clinical term used to describe a particularly dramatic form of acute decompensated heart failure. Well-established risk factors for heart failure such as hypertension, coronary ischemia, valvular heart disease, and diastolic dysfunction are associated with acute decompensated heart failure as well as with FPE. However, endothelial dysfunction possibly secondary to an excessive activity of renin-angiotensin-aldosterone system, impaired nitric oxide synthesis, increased endothelin levels, and/or excessive circulating catecholamines may cause excessive pulmonary capillary permeability and facilitate FPE formation. Renal artery stenosis particularly when bilateral has been identified has a common cause of FPE. Lack of diurnal variation in blood pressure and a widened pulse pressure have been identified as risk factors for FPE. This review is an attempt to delineate clinical and pathophysiological mechanisms responsible for FPE and to distinguish pathophysiologic, clinical, and therapeutic aspects of FPE from those of acute decompensated heart failure.

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.

Early pharmacological treatment of acute heart failure syndromes: A systematic review of clinical trials

CONTEXT

Acute Heart Failure Syndromes (AHFS) is a common admission diagnosis associated with high mortality and hospital readmissions. Given the mixed results of recent clinical trials, the early management of AHFS remains controversial.

OBJECTIVE

To review the recent evidence regarding current and investigational therapies for the early management of AHFS.

DATA SOURCES

A systematic search of peer-reviewed publications was performed on MEDLINE and EMBASE from January 1990 to August 2006. The results of unpublished or ongoing trials were obtained from presentations at national and international meetings and pharmaceutical industry releases. Bibliographies from these references were also reviewed, as were additional articles identified by content experts.

STUDY SELECTION AND DATA EXTRACTION

Criteria used for study selection were controlled study design, relevance to clinicians and validity based on venue of publication and power analysis.

DATA SYNTHESIS

Although all current intravenous therapies for the early management of AHFS appear to improve hemodynamics, this may not always translate into short-term clinical benefit.

CONCLUSION

The results of the trials conducted to date in AHFS have generally been disappointing. There is, therefore, an unmet need for new therapeutic approaches for the early management of AHFS that may improve the short-term and long-term outcomes.

Special cases in acute heart failure syndromes: atrial fibrillation and wide complex tachycardia

Hospitalization for acute heart failure syndromes (AHFS) results in substantial in-hospital and postdischarge morbidity and mortality. Management of AHFS presents significant challenges, given the heterogeneity of the patient population and the differing etiologies underlying why patients present with acute decompensation. Arrhythmias in the setting of AHFS, such as atrial fibrillation and wide complex tachycardia, present additional challenges. Compounding this challenge is the paucity of evidence on which to base early management. General principles for the management of atrial fibrillation and wide complex tachycardia in the setting of emergency department AHFS are discussed.

Acute hemodynamic effects of tolvaptan, a vasopressin V2 receptor blocker, in patients with symptomatic heart failure and systolic dysfunction: an international, multicenter, randomized, placebo-controlled trial

OBJECTIVES

This study sought to assess the acute hemodynamic effect of vasopressin V(2) receptor antagonism.

BACKGROUND

In decompensated heart failure (HF), tolvaptan, a vasopressin V(2) receptor antagonist, has been shown to improve congestion. It has not yet been established whether these improvements may be associated with the hemodynamic effects of tolvaptan.

METHODS

A total of 181 patients with advanced HF on standard therapy were randomized to double-blind treatment with tolvaptan at a single oral dose (15, 30, or 60 mg) or placebo.

RESULTS

Tolvaptan at all doses significantly reduced pulmonary capillary wedge pressure (-6.4 +/- 4.1 mm Hg, -5.7 +/- 4.6 mm Hg, -5.7 +/- 4.3 mm Hg, and -4.2 +/- 4.6 mm Hg for the 15-mg, 30-mg, 60-mg, and placebo groups, respectively; p < 0.05 for all tolvaptan vs. placebo). Tolvaptan also reduced right atrial pressure (-4.4 +/- 6.9 mm Hg [p < 0.05], -4.3 +/- 4.0 mm Hg [p < 0.05], -3.5 +/- 3.6 mm Hg, and -3.0 +/- 3.0 mm Hg for the 15-mg, 30-mg, 60-mg, and placebo groups, respectively) and pulmonary artery pressure (-5.6 +/- 4.2 mm Hg, -5.5 +/- 4.1 mm Hg, -5.2 +/- 6.1 mm Hg, and -3.0 +/- 4.7 mm Hg for the 15-mg, 30-mg, 60-mg, and placebo groups, respectively; p < 0.05). Tolvaptan increased urine output by 3 h in a dose-dependent manner (p < 0.0001), without changes in renal function.

CONCLUSIONS

In patients with advanced HF, tolvaptan resulted in favorable but modest changes in filling pressures associated with a significant increase in urine output. These data provide mechanistic support for the symptomatic improvements noted with tolvaptan in patients with decompensated HF. (Heart Pressure Assessment Study With Tolvaptan to Treat Congestive Heart Failure; NCT00132886).

Current treatment options for early management in acute decompensated heart failure

Acute decompensated heart failure (ADHF) is a common syndrome that precedes over 100,000 hospitalizations in Canada per year (with length of stay in excess of six to eight days), making this the most costly disorder for patients older than 65 years of age. Over 85% of ADHF patients present with shortness of breath and exhibit evidence of volume overload. These findings may be variable in elderly patients, which complicates diagnosis. In fact, even in experienced centres, diagnostic accuracy is less than 80%. Despite advances in the treatment of chronic heart failure, meaningful improvements in outcomes associated with ADHF are very few. The basic assessment and treatments have not changed (early parenteral diuretics, electrocardiographic and oxygen saturation monitoring, supplemental oxygen administration). The introduction of measurement of natriuretic peptides in those in whom the diagnosis is uncertain may reduced the error rate by over 50%. The use of vasodilator therapy in the absence of cardiogenic shock can lead to earlier amelioration of symptoms, especially in those who do not respond to initial diuretics. Repeated monitoring of vital signs, body weight, electrolytes and creatinine levels is essential to minimize the risk of side effects of treatments. Noninvasive ventilation may reduce the need for endotracheal intubation in patients with severe ADHF and hypoxia at rest. Once the initial phase of heart failure treatment is completed, then the clinician should begin to focus on maximization of chronic heart failure therapy and discharge planning.

Assisting the failing heart

Anesthesiologists increasingly encounter patients who have a spectrum of heart failure ranging from stable chronic heart failure to acute heart failure to cardiogenic shock. Improved medical therapy has increased the survival of patients who have chronic heart failure but not of patients who have acute heart failure. New surgical techniques and mechanical devices may offer alternatives to certain patients who have refractory heart failure This article provides an overview of established and newer pharmacologic and nonpharmacologic therapies and surgical interventions to manage patients who have heart failure, including the perioperative management of heart transplantation and ventricular assist devices.

Overview of emerging pharmacologic agents for acute heart failure syndromes

BACKGROUND

Several therapies commonly used for the treatment of acute heart failure syndromes (AHFS) present some well-known limitations and have been associated with an early increase in the risk of death. There is, therefore, an unmet need for new pharmacologic agents for the early management of AHFS that may improve both short- and long-term outcomes.

AIM

To review the recent evidence on emerging pharmacologic therapies in AHFS.

METHODS

A systematic search of peer-reviewed publications was performed on MEDLINE, EMBASE and Clinical Trials.gov from January 1990 to August 2007. The results of unpublished or ongoing trials were obtained from presentations at national and international meetings and pharmaceutical industry releases. Bibliographies from these references were also reviewed, as were additional articles identified by content experts.

RESULTS

Cumulative data from large studies and randomised trials suggest that therapies with innovative mechanisms of action may safely and effectively reduce pulmonary congestion or improve cardiac performance in AHFS patients.

CONCLUSION

Some investigational agents for the management of AHFS are able to improve haemodynamics and/or clinical status. In spite of these promising findings, no new agent has demonstrated a clear benefit in terms of long-term clinical outcomes compared to placebo or conventional 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.

Lack of renal improvement with nonselective endothelin antagonism with tezosentan in type 2 hepatorenal syndrome

Renal vasoconstriction is a key factor in the development of hepatorenal syndrome (HRS) and may be secondary to increased activities of endothelin-1, a potent renal vasoconstrictor. To assess the effects of tezosentan, a nonselective endothelin receptor antagonist, on renal function in patients with type 2 HRS, six male patients, 56.3 +/- 2.5 years old, with cirrhosis and type 2 HRS were treated with tezosentan; ascending doses of 0.3, 1.0, and 3.0 mg/hour, each for 24 hours, were used for the initial 2 patients, but a constant dose of 0.3 mg/hour for up to 7 days was used for the remaining 4 patients. The glomerular filtration rate, renal plasma flow, 24-hour urinary volume, mean arterial pressure (MAP), heart rate, tezosentan levels, and vasoactive hormones were measured daily. Albumin was given as required. The study was stopped early because of concerns about the safety of tezosentan in type 2 HRS. Five patients discontinued the study early; one stopped within 4 hours because of systemic hypotension (MAP < 70 mm Hg), and 4 patients stopped at approximately 4 days because of concerns about worsening renal function (serum creatinine increased from 180 +/- 21 to 222 +/- 58 micromol/L, P > 0.05) and decreasing urine volume (P = 0.03) but without a significant change in MAP. The plasma tezosentan concentrations were 79 +/- 34 ng/mL at a steady state during infusion at 0.3 mg/hour. The plasma endothelin-1 concentrations increased from 2.7 +/- 0.3 pg/mL at the baseline to 19.1 +/- 7.3 pg/mL (P < 0.05).

CONCLUSION

An endothelin receptor blockade potentially can cause a deterioration in renal function in patients with cirrhosis and type 2 HRS. Caution should be taken in future studies using endothelin receptor antagonists in these patients.