Bridging to heart transplantation: prostaglandin E1 versus prostacyclin versus dobutamine

Ambulatory Inotrope Infusions in Advanced Heart Failure: A Systematic Review and Meta-Analysis

OBJECTIVES

This study sought to systematically review the available evidence of risks and benefits of ambulatory intravenous inotrope therapy in advanced heart failure (HF).

BACKGROUND

Ambulatory inotrope infusions are sometimes offered to patients with advanced Stage D HF; however, an understanding of the relative risks and benefits is lacking.

METHODS

On August 7, 2016, we searched SCOPUS, Web of Science, Ovid EMBASE, and Ovid MEDLINE for studies of long-term use of intravenous inotropes in outpatients with advanced HF. Meta-analysis was performed using random effects models.

RESULTS

A total of 66 studies (13 randomized controlled trials and 53 observational studies) met inclusion criteria. Most studies were small and at high risk for bias. Pooled rates of death (41 studies), all-cause hospitalization (15 studies), central line infection (13 studies), and implantable cardioverter-defibrillator shocks (3 studies) of inotropes were 4.2, 22.2, 3.6, and 2.4 per 100 person-months follow-up, respectively. Improvement in New York Heart Association (NYHA) functional class was greater in patients taking inotropes than in controls (mean difference of 0.60 NYHA functional classes; 95% confidence interval [CI]: 0.22 to 0.98; p = 0.001; 5 trials). There was no significant difference in mortality risk in those taking inotropes compared with controls (pooled risk ratio: 0.68; 95% CI: 0.40 to 1.17; p = 0.16; 9 trials). Data were too limited to pool for other outcomes or to stratify by indication (i.e., bridge-to-transplant or palliative).

CONCLUSIONS

High-quality evidence for the risks and benefits of ambulatory inotrope infusions in advanced HF is limited, particularly when used for palliation. Available data suggest that inotrope therapy improves NYHA functional class and does not impact survival.

Inotropic agents and vasodilator strategies for the treatment of cardiogenic shock or low cardiac output syndrome

BACKGROUND

Cardiogenic shock (CS) and low cardiac output syndrome (LCOS) as complications of acute myocardial infarction (AMI), heart failure (HF) or cardiac surgery are life-threatening conditions. While there is a broad body of evidence for the treatment of people with acute coronary syndrome under stable haemodynamic conditions, the treatment strategies for people who become haemodynamically unstable or develop CS remain less clear. We have therefore summarised here the evidence on the treatment of people with CS or LCOS with different inotropic agents and vasodilative drugs. This is the first update of a Cochrane review originally published in 2014.

OBJECTIVES

To assess efficacy and safety of cardiac care with positive inotropic agents and vasodilator strategies in people with CS or LCOS due to AMI, HF or cardiac surgery.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase and CPCI-S Web of Science in June 2017. We also searched four registers of ongoing trials and scanned reference lists and contacted experts in the field to obtain further information. No language restrictions were applied.

SELECTION CRITERIA

Randomised controlled trials in people with myocardial infarction, heart failure or cardiac surgery complicated by cardiogenic shock or LCOS.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We identified 13 eligible studies with 2001 participants (mean or median age range 58 to 73 years) and two ongoing studies. We categorised studies into eight comparisons, all against cardiac care and additional other active drugs or placebo. These comparisons investigated the efficacy of levosimendan versus dobutamine, enoximone or placebo, epinephrine versus norepinephrine-dobutamine, amrinone versus dobutamine, dopexamine versus dopamine, enoximone versus dopamine and nitric oxide versus placebo.All trials were published in peer-reviewed journals, and analysis was done by the intention-to-treat (ITT) principle. Twelve of 13 trials were small with few included participants. Acknowledgement of funding by the pharmaceutical industry or missing conflict of interest statements emerged in five of 13 trials. In general, confidence in the results of analysed studies was reduced due to serious study limitations, very serious imprecision or indirectness. Domains of concern, which show a high risk of more than 50%, include performance bias (blinding of participants and personnel) and bias affecting the quality of evidence on adverse events.Levosimendan may reduce short-term mortality compared to a therapy with dobutamine (RR 0.60, 95% CI 0.37 to 0.95; 6 studies; 1776 participants; low-quality evidence; NNT: 16 (patients with moderate risk), NNT: 5 (patients with CS)). This initial short-term survival benefit with levosimendan vs. dobutamine is not confirmed on long-term follow up. There is uncertainty (due to lack of statistical power) as to the effect of levosimendan compared to therapy with placebo (RR 0.48, 95% CI 0.12 to 1.94; 2 studies; 55 participants, very low-quality evidence) or enoximone (RR 0.50, 95% CI 0.22 to 1.14; 1 study; 32 participants, very low-quality evidence).All comparisons comparing other positive inotropic, inodilative or vasodilative drugs presented uncertainty on their effect on short-term mortality with very low-quality evidence and based on only one RCT. These single studies compared epinephrine with norepinephrine-dobutamine (RR 1.25, 95% CI 0.41 to 3.77; 30 participants), amrinone with dobutamine (RR 0.33, 95% CI 0.04 to 2.85; 30 participants), dopexamine with dopamine (no in-hospital deaths from 70 participants), enoximone with dobutamine (two deaths from 40 participants) and nitric oxide with placebo (one death from three participants).

AUTHORS' CONCLUSIONS

Apart from low quality of evidence data suggesting a short-term mortality benefit of levosimendan compared with dobutamine, at present there are no robust and convincing data to support a distinct inotropic or vasodilator drug-based therapy as a superior solution to reduce mortality in haemodynamically unstable people with cardiogenic shock or LCOS.Considering the limited evidence derived from the present data due to a generally high risk of bias and imprecision, it should be emphasised that there remains a great need for large, well-designed randomised trials on this topic to close the gap between daily practice in critical care medicine and the available evidence. It seems to be useful to apply the concept of 'early goal-directed therapy' in cardiogenic shock and LCOS with early haemodynamic stabilisation within predefined timelines. Future clinical trials should therefore investigate whether such a therapeutic concept would influence survival rates much more than looking for the 'best' drug for haemodynamic support.

Outcome of conservative management vs. assist device implantation in patients with advanced refractory heart failure

BACKGROUND

In patients with advanced refractory heart failure (HF) cardiac transplantation (HTX), conservative medical management and the implantation of a ventricular assist device (VAD) represent valuable options. The determination of the best therapeutic destination strategy for the individual patient remains a challenge. The aim of this study was to assess the clinical outcome in advanced refractory HF patients either managed conservatively receiving optimal contemporary medical therapy ('conservative'), or who who underwent pulsatile flow VAD ('pVAD') or continuous-flow VAD ('contVAD') implantation.

MATERIALS AND METHODS

A total of 118 patients with INTERMACS profile >1 at baseline, who died, or fully completed a 24-month follow-up free from HTX were included into this retrospective analysis. All-cause mortality at 24 months was assessed and compared between the three groups.

RESULTS

Fifty (42%) patients were managed conservatively, 25 (21%) received a pVAD and 43 (36%) a contVAD. NT-proBNP values were comparable between the three groups (median 4402 (IQR 2730-13390) pg/mL, 3580 (1602-6312) pg/mL and 3693 (2679-8065) pg/mL, P = 0·256). Mean survival was 18·6 (95% CI 16·2-21·0) months for patients managed conservatively, 7·0 (3·9-10·0) for pVAD and 20·5 (18·2-22·8) for contVAD (overall log-rank test P < 0·001). Conservatively managed patients spent a mean of 22·4 (95% CI 22·1-22·8), pVAD 17·7 (15·4-20·1) and contVAD 21·6 (21·2-22·1) months out of hospital (conservative vs. pVAD P < 0·001; conservative vs. contVAD P = 0·015; pVAD vs. contVAD P < 0·001).

CONCLUSIONS

In accordance with the literature, contVAD resulted in a significantly better clinical outcome than pVAD implantation. However, conservative management with current optimal medical therapy appears to remain a valuable option for patients with advanced HF.

Study of molecular mechanism of Prostaglandin E1 in inhibiting coronary heart disease

Prostaglandin E1 has been used clinically for improving heart diseases. In this study, we examined the effect of Prostaglandin E1 on blood lipid levels, heart protein and genes expression in coronary heart disease (CHD) rats. Female rats were fed either a control diet or hypercholesterolemic diet for 14 weeks. The feeding of a hypercholesterolemic diet (HCD) increased the serum TC, TG, and LDL-c levels, decreased the serum HDL-c, E2, P, FSH, LH and PRL levels in CHD rats. In addition, The feeding of a HCD diet markedly increased the content of serum TXA2, TXB2, and decreased the content of serum PGI2, and PGI2/TXA2, 6-Keto PGF1a. Furthermore, the feeding of a hypercholesterolemic diet markedly increased expression levels of myocardium Fas and Caspase-3 protein and mRNA levels, vascular endothelial growth factor and basic fibroblast growth factor mRNA, and decreased RyR2 mRNA in CHD rats. The feeding of Prostaglandin E1 for 14 weeks significantly reversed these abnormal biochemical indexes in rats. These findings suggest that Prostaglandin E1 play a obvious heart protective effect. The mechanisms may be related to restraining the excessive activation of Fas and Caspase-3 protein and modulating some gene expressions associated with CHD.

Continuous intravenous infusion of prostaglandin E1 improves myocardial perfusion reserve in patients with ischemic heart disease assessed by positron emission tomography: a pilot study

OBJECTIVE

Recent investigation has demonstrated that prostaglandin E(1) (PGE(1)) therapy increased capillary density in explanted hearts. Dynamic (13)N-ammonia positron emission tomography (PET) is reliable for non-invasive measurement of myocardial blood flow and myocardial perfusion reserve (MPR). The aim of this study was to investigate the effects of PGE(1) therapy during 4 weeks on reduction of myocardial perfusion abnormalities and increase of MPR in the patients with ischemic heart disease.

METHODS

In this double-blind, placebo-controlled trial, we randomly assigned 11 patients who had symptomatic heart failure and documented myocardial ischemia to 4 weeks intravenous infusion of PGE(1) (2.5 ng/kg/min; 8 patients, age 60 ± 13 years) or saline (3 patients, age 57 ± 13 years). Dynamic (13)N-ammonia PET scans at rest and during adenosine stress were obtained at baseline and 12 weeks after treatment completion. Quantitative size/severity of perfusion defects and MPR change from baseline to follow-up PET were determined using a 17-segment model.

RESULTS

Compared with the control group, baseline MPR in the PGE(1) group was significantly lower (1.96 ± 0.78 vs. 2.71 ± 0.73; P < 0.001). MPR significantly improved 12 weeks after completion of PGE(1) infusion (1.96 ± 0.78 to 2.16 ± 0.77; P < 0.001). In contrast, MPR declined significantly in the placebo group (2.71 ± 0.73 to 2.01 ± 0.58, P < 0.001).

CONCLUSION

Four weeks of PGE(1) infusion sustained MPR improvement in patients with ischemic heart disease. This may be an attractive therapeutic approach for no-option patients with severe ischemic cardiomyopathy.

Pulmonary hypertension in heart failure

BACKGROUND

Pulmonary hypertension occurs in 60% to 80% of patients with heart failure and is associated with high morbidity and mortality.

METHODS AND RESULTS

Pulmonary artery pressure correlates with increased left ventricular end-diastolic pressure. Therefore, pulmonary hypertension is a common feature of heart failure with preserved as well as reduced systolic function. Pulmonary hypertension is partially reversible with normalization of cardiac filling pressures. Pulmonary vasculature remodeling and vasoconstriction create a second component, which does not reverse immediately, but has been shown to improve with vasoactive drugs and especially with left ventricular assist devices.

CONCLUSION

Many drugs used for idiopathic pulmonary arterial hypertension are being considered as treatment options for heart failure-related pulmonary hypertension. This is of particular significance in the heart transplant population. Randomized clinical trials with interventions targeting heart failure patients with elevated pulmonary artery pressure would be justified.

Pulmonary hypertension in chronic heart failure

The presence of PH in patients who suffer from CHF is common and predicts a poor outcome. However, precise definitions for PH associated with left heart disease, or 'out-of-proportion' PH as well as standardised vasodilator testing protocols are lacking. Moreover, apart from single-centre observations no large-scale trial to date has demonstrated a long-term benefit from pulmonary vasoactive drugs. As a result, there are currently no consensus recommendations for the treatment of PH in the presence of CHF. Off-label use of specific vasodilators in this patient population is discouraged. In a majority of cases, treatment of the underlying left heart disease leads to a decrease in pulmonary pressures. In light of novel agents to treat PH, trials that specifically address 'out-of-proportion' PH in CHF patients are warranted.

Benefit of prostaglandin infusion in severe heart failure: preliminary clinical experience of repetitive administration

BACKGROUND

Prostaglandin E1 (PGE1) is a potent vasodilating drug, which has been used in treatment of primary pulmonary hypertension. However intravenous PGE1 infusion may be of benefit and also has been proposed as a therapeutic tool in patients with end-stage heart failure. The aim of this prospective not randomized study was to assess the clinical and instrumental effects of this agent in patients with severe heart failure and pulmonary hypertension.

METHODS

To investigate the effects of PGE1 in congestive heart failure we selected 22 consecutive patients (16 males, 6 females, mean age 63±2 years) in the mean NYHA class III, because they had pulmonary hypertension (PAPs>3 m/s and left ventricular ejection fraction (LVEF) ≤35% by echocardiography. A control group of 23 patients (19M, 4F mean age 62±5 years; 9 patients were in the NYHA class IV and 14 in the NYHA class III), with the same instrumental and clinical data, received an optimized oral treatment with beta-blockers, ACE-inhibitors, furosemide and digitalis. Right heart catheterization was performed to confirm and determine the type of pulmonary hypertension, before starting the PGE1 infusion. Clinical and echocardiography evaluation was performed during follow-up. PGE1 was infused at a mean dose of 10 ng/kg/min for a total of 24 h over three consecutive days every three months.

RESULTS

Right heart catheterization confirmed a high systolic pulmonary pressure in all patients; pre-capillary pulmonary hypertension (mean PAP>25 mm/Hg) was 25%. During a mean follow-up of 36±6 months, 16 patients died (10 in the control group and 6 in the PGE1 group). The Kaplan-Meier 3-years survival analysis was not statistically significant (Log-rank test), but at 2 months survival rates began to diverge; 36 months survival: 72.7% in the PGE1 group and 56% in the control group. The mean LVEF increased from 25.78% to 32.1% in the PGE1 group and from 23.38% to 26.15 in the control group (p<0.001); the NYHA mean class improved from 3.18 to 2.24 in the PGE1 group and from 3.46 to 3.38 in the control group (p<0.05). The PAP decreased from 57.65 to 40.82 mm/Hg (p<0.001). An AICD was implanted in 3 patients in the first group and in 5 patients in the control group. Two patients were added to the heart transplantation list.

CONCLUSION

These preliminary data suggest that intermittent PGE1 infusion in patients with advanced congestive heart failure and high pulmonary pressure is able to improve NYHA mean class (p<0.05), ventricular contractility (LVEF p<0.001), pulmonary pressure and clinical data. It hasn't been associated to morbid events or increased risk of death.

Levosimendan and prostaglandin E1 for uptitration of beta-blockade in patients with refractory, advanced chronic heart failure

BACKGROUND

In advanced chronic heart failure (CHF) 20% of patients do not tolerate beta-blockers and 50% do not reach target doses.

AIM

To test whether levosimendan or prostaglandin E1 (PGE1) can facilitate uptitration of beta-blockers in advanced CHF.

METHODS AND RESULTS

Seventy-five advanced CHF patients (LVEF<35%, NYHA class IIIb or IV) intolerant to beta-blocker uptitration to target doses (10 mg bisoprolol/day) were randomised to a monthly 24 h infusion with levosimendan (n=39) or a chronic infusion with PGE1 (n=36) for 3 months. Bisoprolol was uptitrated following predefined criteria. At 12 weeks, bisoprolol dose increased from 4 mg to 10 mg in both groups. Heart failure worsening occurred in 29 levosimendan patients (74%) versus 16 PGE1 patients (44%, p=0.008). Uptitration was impossible in 9 levosimendan patients (23%) versus 2 PGE1 patients (6%, p=0.03). The combined endpoint of death or urgent heart transplantation or implantation of a ventricular assist device was reached by 12 levosimendan patients (31%) versus 4 PGE1 patients (11%, p=0.04). After 1 year, LVEF increased from 23+/-7% to 28+/-11% (p=0.0004), and BNP decreased from 994+/-806 to 659+/-564 pg/ml (p=0.03).

CONCLUSION

Levosimendan and PGE1 facilitate uptitration of beta-blockers in previously intolerant CHF patients. PGE1 treatment allowed uptitration in more patients and resulted in a better clinical outcome compared to levosimendan. This approach increased LVEF and decreased BNP after 1 year.

Reversible pulmonary hypertension in heart transplant candidates: to transplant or not to transplant

BACKGROUND

Pulmonary hypertension (PHT), defined as a pulmonary vascular resistance (PVR) greater than 2.5 Wood units [WU] and(or) transpulmonary gradient (TPG) greater than 12 mm Hg, is a risk factor for mortality in cardiac transplantation due to elevated postoperative right heart failure. Orthotopic heart transplantation is possible if PVR could be reversed below 2.5 WU and TPG below 12 mm Hg. We show the Muenster experience from the last 10 years.

METHODS

From April 1996 to December 2005 all cardiac transplant recipients separated into patients with and without PHT were included. All patients with PHT had successful reduction (PVR < or = 2.5 WU and TPG < or = 12 mm Hg) using prostaglandin I2 or E1. Posttransplant early and late mortality and incidence of right heart failure were studied.

RESULTS

Two hundred seventeen patients were included in this study. Of these, 168 had normal pulmonary pressures (non-PHT group), 49 (22.6%) had reversible PHT (rev-PHT group). Mean PVR was 1.6 +/- 1.1 WU vs 2.1 +/- 1.1 WU (p < 0.01; non-PHT vs rev-PHT) and mean TPG 8.0 +/- 1.9 mm Hg vs 10.6 +/- 4.1 mm Hg (p = not significant [NS]). Thirty-day survival after orthotopic cardiac transplantation was 85% vs 78% (p = 0.150) and 10 year survival 63% vs 61% (p = NS). Right heart failure during the first 30 days after transplantation occurred in 27% in the non-PHT group and in 64% in the rev-PHT group (p = 0.035). However, in patients transplanted after 2001 it did not appear.

CONCLUSIONS

Cardiac transplant candidates with reversible PHT have still significantly elevated pulmonary pressures compared with patients without PHT. Despite a significantly higher risk of right heart failure, long-term survival after orthotopic cardiac transplantation was not affected.

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

BACKGROUND

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

AIMS

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

METHODS AND RESULTS

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

CONCLUSIONS

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

Revascularization of myocardial scar tissue following prostaglandin E1-therapy in patients with ischemic heart disease

Prostaglandin E1 (PGE-1) treatment has proved to stimulate angiogenesis in vital non-infarcted myocardium of patients with ischemic cardiomyopathy (ICMP). We investigated infarcted myocardial tissue for a possible angiogenic response to PGE-1. Neovascularization was investigated in infarcted areas of 12 hearts explanted from patients with ICMP who had been treated with PGE-1 before heart transplantation (HTX). In transmural sections containing myocardial scar tissue, CD34 and VEGF were immunohistochemically quantified to estimate capillary density and the extent of angiogenesis. To investigate a possible effect of PGE-1 on collagen turnover, the collagen content was determined in myocardial scar tissue by assessing the intensity of the area positively stained with sirius red. PGE-1-treated patients had significantly more CD34- and VEGF-positive cells in infarcted areas, and showed a significant reduction in collagen content as compared with the non-PGE-1 group (CD34: 120.3 +/- 6.1 vs. 47.7 +/- 6.1 capillary profiles/mm2; VEGF: 52.8 +/- 5.6 vs. 24.0 +/- 4.8 capillary profiles/mm2, and collagen content: 2.18 +/- 0.4 eU vs. 3.59 +/- 0.38 eU). Our data demonstrate that PGE-1 stimulates angiogenesis by upregulating VEGF expression, and reduces fibrosis in cardiac scar tissue of ischemic origin. The induction of therapeutic angiogenesis in vital and at sites of putative dead myocardial scar tissue, along with the hemodynamic improvement in patients with severe ICMP, might explain the favorable clinical outcome in PGE-1-treated patients before HTX.

Reversible pulmonary hypertension in heart transplant candidates-pretransplant evaluation and outcome after orthotopic heart transplantation

BACKGROUND

Heart transplantation is the most effective treatment for well-selected patients with endstage heart failure. Unfortunately, transplant candidates with pulmonary hypertension (PHT) are often not considered for heart transplantation. This study was performed to assess the value of prostaglandin E(1) (PG-E(1)) for reduction of PHT and to predict the postoperative outcome, compared to patients without PHT.

PATIENTS AND METHODS

We studied a group of 151 consecutive heart transplant candidates using right heart catheterization. In patients with PHT (pulmonary vascular resistance, PVR> or =2.5 Wood-Units (WU) and/or transpulmonary gradient (TPG)> or =12 mmHg) a short-term treatment protocol with PG-E(1) was performed, to achieve PVR<2.5 WU and TPG<12 mmHg.

RESULTS

61 patients (40%) had PHT according to our criteria. Reduction of PHT was successful in 71% of patients (n=43), of these, 18 patients underwent cardiac transplantation and the 1-year mortality rate was 22% (n=4). The 1-year mortality rate in transplanted patients without PHT was 14% (n=3). There was no statistical difference in survival between the PHT and the non-PHT group. Outcome in patients without heart transplantation was similar in both groups, except for patients with non-reducible PHT (1-year mortality 50%).

CONCLUSIONS

Our study demonstrates the efficacy and safety of PG-E(1) in lowering PHT in heart transplant candidates, as well as the need for aggressive evaluation and treatment in these patients. Patients with reversible PHT have comparable post-transplant outcomes and no tendency to higher acute right ventricular failure.

Sequential big endothelin plasma levels in heart transplant recipients during bridging therapy and after successful heart transplantation

BACKGROUND

The purpose of this study was to investigate the impact of successful heart transplantation in patients with refractory heart failure receiving bridging therapy on sequential plasma levels of big endothelin, norepinephrine, atrial natriuretic peptide and aldosterone.

METHODS

Fourteen patients (2 women, 12 men) accepted for heart transplantation were studied. All had severe chronic heart failure refractory to optimized oral therapy with angiotensin-converting enzyme inhibitors and furosemide, were in New York Heart Association functional Class IV, and had a left ventricular ejection fraction of <15%, Right heart catheterization was performed in all patients (cardiac index 1.9 +/- 0.1 liters/min. m(2), pulmonary capillary wedge pressure 30 +/- 2 mmHg, systemic vascular resistance index 2,827 +/- 253 dyn. s/cm(5). m(2)). As bridging therapy, patients received either prostaglandin E(1), prostaglandin E(1) and dobutamine or dobutamine alone as a continuous infusion. Neurohumoral variables were measured prior to bridging therapy and 3.5 months before and 7 and 10 months after successful heart transplantation.

RESULTS

Big endothelin, norepinephrine and atrial natriuretic peptide plasma levels decreased from 7.4 +/- 2.9 fmol/ml, 1112 +/- 686 pg/ml and 366 +/- 312 pg/ml to 6.0 +/- 4.5 fmol/ml, 720 +/- 503 pg/ml and 198 +/- 160 pg/ml, respectively, after bridging therapy, and further to 2.1 +/- 0.9 fmol/ml (p < 0.00001 vs baseline), 527 +/- 31 pg/ml (p < 0.02 vs baseline) and 115 +/- 70 pg/ml (p < 0.03 vs baseline), respectively, after cardiac transplantation. Aldosterone plasma levels decreased from 242 +/- 220 pg/ml to 183 +/- 142 pg/ml during bridging therapy and increased after heart transplantation to 252 +/- 189 pg/ml. Plasma creatinine levels increased from 1.2 +/- 0.4 mg/dl at baseline to 1.4 +/- 0.2 mg/dl after transplantation (NS).

CONCLUSIONS

The study suggests that excessive overproduction of big endothelin, atrial natriuretic peptide and norepinephrine is predominantly related to pump failure and, after cardiac transplantation, a moderate spillover of big endothelin persists. Its specific origin, however, remains to be elucidated. Furthermore, our data suggest a protective effect of prostaglandin E(1) on kidney function after heart transplantation.

Clinical benefit of prostaglandin E1-treatment of patients with ischemic heart disease: stimulation of therapeutic angiogenesis in vital and infarcted myocardium

New evidence suggests that Prostaglandin E1 (PGE-1) stimulates myocardial angiogenesis in human chronic ischemic myocardium. We sought to investigate whether PGE-1 may participate in the process of neoangiogenesis within the myocardial infarct scar. Neovascularization was investigated in 14 explanted hearts from patients with ischemic cardiomyopathy, who had been bridged to heart transplantation (HTX) with PGE-1 and compared with 14 hearts from patients who did not receive PGE-1 prior to HTX. In transmural sections obtained from the left ventricular wall and containing myocardial scar tissue, CD34 and vascular endothelial growth factor (VEGF) were quantified immunohistochemically to estimate capillary density and amount of angiogenesis. Additionally, to assess the hypoxic state of myocardium of the infarct border zone, hypoxia inducible factor 1-alpha (HIF-1alpha) was determined by immunohistochemistry and quantified by means of planimetric analysis. PGE-1-treated patients had significantly more CD34-and VEGF-positive cells in infarct areas as compared to nonPGE-1 group, respectively (CD34: 116.7 +/- 5.9 vs. 45.1 +/- 5.2 capillary profiles/mm(2), P < 0.001, and VEGF: 48.3 +/- 4.9 vs. 22.9 +/- 4.7 capillary profiles/mm(2)). HIF-1alpha enrichment (in %) as well as staining intensity (in estimated units (eU)) was significantly decreased in PGE-1-treated as compared to non-treated controls (enrichment: 11.3 +/- 2.5% vs. 19.4 +/- 4.36%; staining intensity: 0.95 +/- 0.3 vs. 1.97 +/- 0.44 eU). Our data demonstrate that PGE-1 stimulates neoangiogenesis in infarct areas adjacent to viable myocardium, via upregulation of VEGF expression. The induction of therapeutic angiogenesis along with the improved hypoxic state of chronic ischemic myocardial tissue might explain the favorable clinical outcome in PGE-1 treated patients.

Angiogenesis stimulation in explanted hearts from patients pre-treated with intravenous prostaglandin E(1)

BACKGROUND

Prostaglandin E(1) (PGE(1)) is a potent vasodilator and induces angiogenesis in animal tissues. Previous clinical studies demonstrated that PGE(1) improves hemodynamic parameters in patients with heart failure listed for heart transplantation (HTX). Therefore, we designed a retrospective immunohistochemistry study to investigate various markers of angiogenesis using hearts explanted from PGE(1)-treated patients with idiopathic dilated cardiomyopathy (IDCM).

METHODS AND RESULTS

We investigated neovascularization in 18 hearts explanted from patients with IDCM: 9 patients received treatment with chronic infusions of PGE(1) for end-stage heart failure before HTX, whereas the remaining patients with IDCM did not receive PGE(1) and served as controls. We used immunoreactivity against CD34, von Willebrand factor (vWf), vascular endothelial growth factor (VEGF), and MIB-1 (Ki-67) to quantify angiogenesis, and used sirius red staining to determine the degree of fibrosis. Compared with the control group, PGE(1)-treated patients had significantly more CD34-, vWf- and MIB-1-positive cells in the sub-endocardium, myocardium and sub-epicardium (p < 0.01). The degree of fibrosis in the hearts of PGE(1)-treated patients was significantly lower than in control patients (p < 0.05), but we did not see any difference in the percentage of muscle mass. Finally, throughout the ventricles, we found significantly more VEGF-positive capillaries in the PGE(1) group (p < 0.0001).

CONCLUSIONS

The data suggest that PGE(1) could be a potent inducer of angiogenesis and the angiogenic factor VEGF, and could cause reduced fibrosis in the failing human heart.

Response of right ventricular function to prostaglandin E1 infusion predicts outcome for severe chronic heart failure patients awaiting urgent transplantation

BACKGROUND

Selection of patients for urgent heart transplantation who have end-stage heart failure requires objective criteria to distinguish between subjects who may deteriorate clinically and those who can be stabilized. This population appears to differ in terms of right ventricular function, and right ventricular changes in loading may provide prognostic information. To investigate predictive parameters of patients admitted for urgent heart transplantation, we prospectively studied the mechanical performance of the right ventricle during acute afterload reduction.

PATIENTS AND METHODS

We studied 68 heart failure patients hospitalized for bridge-to-transplant. The patients underwent right heart catherization at baseline and during prostaglandin E1 infusion. We stratified patients according to clinical outcome: Group A comprised patients who could be weaned from bridging therapy or who were electively transplanted after at least 90 days, and Group B comprised patients who died or who remained unstable and required transplant under urgent conditions.

RESULTS

Right ventricular hemodynamics at baseline were comparable in both groups. However, during maximal vasodilatation, with prostaglandin E1 infusion, the right ventricular end-diastolic volume index (EDVI) was significantly reduced in Group A, (-23 ml/m(2) (p < 0.01) vs +12 ml/m(2) (p = n.s. DeltaEDVI in Group B. Reduction of EDVI by less than 10% during prostaglandin E1 infusion has a sensitivity of 89% and a specificity of 70% for clinical deterioration.

CONCLUSIONS

The response of right ventricular volumes to prostaglandin E1 may predict the outcome of patients with severe congestive heart failure listed for urgent heart transplantation.

Prognostic value of hemodynamic vs big endothelin measurements during long-term IV therapy in advanced heart failure patients

STUDY OBJECTIVE

To compare hemodynamics and plasma big endothelin levels in patients awaiting heart transplantation who are receiving continuous IV therapy, and to establish their respective potency for predicting future cardiac events.

DESIGN

A randomized, prospective trial of ambulatory continuous treatment with IV prostaglandin E(1) (PGE(1)) vs dobutamine. A subanalysis was conducted of all patients who completed 4 weeks of follow-up in regard to treatment effects on hemodynamics and big endothelin plasma levels.

PATIENTS

Thirty-two listed heart transplant candidates who were refractory to oral treatment, 21 patients who were receiving PGE(1), and 11 patients receiving dobutamine.

MEASUREMENTS AND RESULTS

Hemodynamics and plasma big endothelin levels were measured at baseline and after 4 weeks. The cardiac index increased significantly (PGE(1) group, 1.7 +/- 0.4 vs 2.5 +/- 0.6 L/min/m(2); dobutamine group, 1.8 +/- 0.3 vs 2.3 +/- 0.6 L/min/m(2); p < 0.05), whereas the systemic vascular resistance index (SVRI) decreased significantly only in the PGE(1) group (3,352 +/- 954 vs 2,178 +/- 519 dyne. s. cm(-5)/m(2); p < 0. 05). The plasma big endothelin level decreased significantly (PGE(1) group, 7.6 +/- 3.1 vs 4.7 +/- 2.6 fmol/mL; dobutamine group, 6.5 +/- 3.7 vs 5.0 +/- 2.6 fmol/mL; p < 0.01 for the time effect). Plasma big endothelin (beta = 0.393; chi(2) = 10.8; p = 0.001) and SVRI (beta = 0.003; chi(2) = 6.9; p < 0.01), both measured after 4 weeks of continuous treatment, were the only independent predictors of future outcome.

CONCLUSION

Continuous treatment over 4 weeks with either PGE(1) or dobutamine in patients awaiting heart transplantation yields an improved hemodynamic state accompanied by a reduction of increased big endothelin levels. Plasma big endothelin measured after 4 weeks of continuous therapy provides prognostic information about future outcome.

Intravenous therapy for advanced heart failure

Because of the standard use of oral neurohumoral antagonists, the role of intravenous agents for advanced heart failure patients has changed profoundly. Their current use as medical therapy is restricted to two indications: first, as short-term infusion (hours to days) in advanced heart failure patients who decompensate into a symptomatic New York Heart Association class IV condition and who are admitted for rapid hemodynamic support with intravenous vasodilators or inotropes; in these patients after hemodynamic and clinical stabilization, optimization of conventional heart failure therapy has to be reconsidered; second, as long-term application in heart transplantation candidates who are in a similar desperate condition although already receiving maximal oral heart failure therapy.

Optimising management of patients with advanced heart failure: the importance of preventing progression

Heart failure is a highly complex, progressive and deadly disease. When incorrectly treated, it results in irreversible structural damage to the myocardium and resists any conventional treatment. This stage has been arbitrarily termed refractory heart failure. However, with timely and sufficiently applied neurohumoral antagonists, progression can be prevented, or at least delayed. In contrast, as soon as heart failure has become moderate or severe due to advanced left ventricular dysfunction, polypharmacy is the rule. Physicians should make every effort to maintain or reconsider optimal neurohumoral antagonist therapy in such patients, even if symptomatic improvement from these agents may be slow. Proper use of diuretics is essential not only for symptom relief but also to achieve full benefit from angiotensin converting enzyme inhibitors and beta-blockers. Digitalis may be particularly indicated in severe heart failure, irrespective of rhythm. Adjunctive regimens can be helpful in specific patients, but evidence of their salutary effects to prolong life is lacking. In the decompensated state, tailoring intravenous therapy to haemodynamic goals followed by (re-)institution of optimal oral therapy is an option. Only if these strategies fail is heart transplantation justified. While waiting for a donor, patients have been bridged with various intravenous agents, most often inotropes, but symptom relief is associated with risk of increased mortality due to these drugs. New hope emerges from drugs interfering with endothelin and the cytokines, and from research into increasing contractility with calcium sensitising agents. Even though these developments follow established routes, they may enable a more effective approach to prevent worsening heart failure in every single patient.