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The development of the promising agent sacubitril/valsartan, known as an angiotensin receptor blocker-neprilysin inhibitor ( ARNI), to improve heart failure ( HF) management, may benefit morbidity, mortality, and readmission rates in patients with HF. The PARADIGM- HF trial demonstrated that the ARNI can reduce morbidity and mortality in patients with heart failure with reduced ejection fraction ( HFr EF), while ongoing PARAMOUNT and PARAGON- HF trials determined whether the ARNI has morbidity and mortality benefits in patients with heart failure with preserved ejection fraction ( HFp EF). However, the risk of long-term side effects of the ARNI such as cognitive dysfunction or Alzheimer's disease ( AD) remains unknown. In fact, neprilysin ( NEP), encoded by NEP or MME gene, is a principal peptidase involved in the degradation of β-amyloid (Aβ) protein. Several studies have demonstrated that polymorphisms of the NEP gene may be associated with AD and cerebral amyloid angiopathy ( CAA). Pharmacogenomics, the study of variability in drug response due to genetic polymorphisms, can potentially explain the variability in the effect of the ARNI and their side effects. Therefore, we have attempted to highlight pharmacogenomic factors and potential long-term side effects of the ARNI. Physicians should carefully monitor elderly patients with genetic risk factors for AD and CAA. In the future, genetic testing and genomic testing for NEP polymorphisms may play an important role in monitoring long-term side effects in ARNI-treated HF patients. [ABSTRACT FROM AUTHOR]

The renin-angiotensin-aldosterone system (RAAS) is an important pathway that contributes to the pathophysiology of acute liver injury due to paracetamol toxicity. Omapatrilat, a RAAS-acting agent, inhibits both angiotensin converting enzyme (ACE) and neprilysin/neutral endopeptidase (NEP). The aim of the present study was to investigate the hepatoprotective effects of omapatrilat and examine the role of ACE/NEP pathway on the physiopathology of paracetamol toxicity. A total of 56 BALB/c mice were separated into seven groups: Control, 40 mg/kg omapatrilat only, 400 mg/kg paracetamol only, paracetamol and 140 mg/kg N-acetylcysteine and three groups with paracetamol and 10-40 mg/kg omapatrilat. Blood and liver tissue samples were studied through histopathological imaging, alanine transaminase (ALT) and aspartate transaminase (AST) liver function tests and oxidant/antioxidant biomarker measurements including superoxide dismutase (SOD), glutathione (GSH) and malondialdehyde (MDA). ACE and NEP activities were also measured. Histopathological analysis revealed that paracetamol toxicity resulted in a number of apoptotic and necrotic cells in liver tissue samples. By contrast, with 40 mg/kg omapatrilat administration in toxicity-induced mice, hepatocytes were significantly improved and exhibited similar appearance to the control group. Biochemical measurements also supported these histopathological results. Omapatrilat pretreatment provided a dose-dependent reduction in oxidative stress and reversed paracetamol toxicity indications by reducing ALT and AST activities, increasing SOD activity and GSH levels and reducing MDA levels. Dose-dependent increase of ACE and NEP enzymes in omapatrilat groups was also observed. The results demonstrated promotion of antioxidant activity by omapatrilat and suppression of oxidative stress associated with acute liver injury. These findings revealed the potential role of ACE/NEP pathway in paracetamol toxicity and hepatoprotective effects of omapatrilat against oxidative stress. [ABSTRACT FROM AUTHOR]

What is known and objective: Heart failure remains a leading cause of morbidity and mortality worldwide. Advanced therapies have prolonged survival in patients with advanced heart failure, but pharmacotherapeutic optimization remains the mainstay of treatment. It has been over 10 years since the last mortality-reducing medication has been approved by the Food and Drug Administration. This article reviews the background, current knowledge and data supporting the use of sacubitril/valsartan (Entresto®), the newly FDA-approved medication that dually inhibits angiotensin and neprilysin, in the treatment of heart failure. Methods: A literature search was performed (January 1980 to August 2015) using PubMed and the search terms were as follows: neprilysin inhibitor, heart failure, endopeptidase, natriuretic peptides, angiotensin, omapatrilat, LCZ696, valsartan and sacubitril. Peer-reviewed, published clinical trials, review articles, relevant treatment guidelines and prescribing information documents were identified and reviewed for relevance. Additionally, reference citations from publications identified were reviewed. Results and discussion: The inhibition of endopeptidases has been an area of extensive study for the treatment of heart failure. Previously published literature with the endopeptidase inhibitor omapatrilat failed to demonstrate a sufficient balance between clinical efficacy and safety to justify its approval. Omapatrilat blocked three pathways that break down bradykinin, leading to high rates of angioedema. Sacubitril, on the other hand, is metabolized to a form that is highly selective for neprilysin without possessing activity for the other two peptidases, ACE and APP. The combination of sacubitril with valsartan in a single formulation offers the benefit of concurrent blockade of the renin angiotensin aldosterone system and the inhibition of neprilysin while minimizing angioedema risk. When compared to ACE inhibitor therapy in systolic heart failure patients, sacubitril/valsartan demonstrated reductions in all-cause mortality and hospitalization due to heart failure while maintaining a similar safety profile. What is new and conclusion: A formulation that contains both sacubitril and valsartan was manufactured and approved by the FDA in July 2015 for the reduction of mortality and hospitalization in systolic heart failure patients. The new medication offers a potentially superior alternative to ACE inhibitor therapy in the management of systolic heart failure. The effects of treatment with sacubitril/valsartan in the setting of diastolic heart failure are currently under investigation in clinical trials. [ABSTRACT FROM AUTHOR]

Purpose New compounds with neprilysin or neutral endopeptidase (NEP) inhibiting activity are under clinical investigation in heart failure and hypertension. We investigated the effect of NEP inhibition on the functional vasomotor responses to a range of vasoactive peptides in human blood vessels. Methods Small human resistance arteries from patients with coronary artery disease and preserved left ventricular systolic function were studied. Thiorphan (a NEP inhibitor) was compared with captopril (an ACE inhibitor) and omapatrilat (a dual NEP-ACE inhibitor) with regard to their effects on the response of human arteries to key vasoactive peptides. Results As expected, both captopril and omapatrilat (but not thiorphan) inhibited the vasoconstrictor effect of angiotensin I (maximal response [SEM]: 27 ± 8% vehicle, 6 ± 2% captopril, 39 ± 10% thiorphan, 8 ± 7% omapatrilat, P < 0.05). Thiorphan, captopril, and omapatrilat all enhanced the vasodilator response to bradykinin (all P < 0.01). Omapatrilat markedly augmented the vasodilator action of adrenomedullin ( P < 0.05), whilst thiorphan and captopril did not. None of the three inhibitors studied affected the vasodilator action of c-type natriuretic peptide, calcitonin gene-related peptide, vasoactive intestinal polypeptide or substance P. Conclusions NEP inhibition with thiorphan modestly augmented the vasodilator action of bradykinin, but did not potentiate the response to adrenomedullin; dual ACE and NEP inhibition with omapatrilat, as expected, markedly augmented the response to bradykinin and also potentiated the effect of adrenomedullin. Thiorphan weakly enhanced the vasoconstrictor response to angiotensin I. Neither omapatrilat nor thiorphan had any effect on the action of a range of other vasoactive peptides including CNP. [ABSTRACT FROM AUTHOR]

Background and Purpose: Inhibition of bradykinin metabolizing enzymes (BMEs) can cause acute angioedema, as demonstrated in a recent clinical trial in patients administered the antihypertensive, omapatrilat. However, the relative contribution of specific BMEs to this effect is unclear and confounded by the lack of a predictive pre-clinical model of angioedema.Experimental Approach: Rats were instrumented to record blood pressure and heart rate; inhibitors were infused for 35 min and bradykinin was infused during the last 5 min to elicit hypotension, as a functional marker of circulating bradykinin and relative angioedema risk.Key Results: In the presence of omapatrilat bradykinin produced dose-dependent hypotension, an effect abolished by B(2) blockade. In the presence of lisinopril (ACE inhibitor), but not candoxatril (NEP inhibitor) or apstatin (APP inhibitor), bradykinin also elicited hypotension. Lisinopril-mediated hypotension was unchanged with concomitant blockade of NEP or NEP/DPPIV (candoxatril+A-899301). However, hypotension was enhanced upon concomitant blockade of APP and further intensified in the presence of NEP inhibition to values not different from omapatrilat alone.Conclusions and Implications: We demonstrated that bradykinin is degraded in vivo with an enzyme rank-efficacy of ACE>APP>>NEP or DPPIV. These results suggest the effects of omapatrilat are mediated by inhibition of three BMEs, ACE/APP/NEP. However, dual inhibition of ACE/NEP or ACE/NEP/DPPIV elicits no increased risk of angioedema compared to ACE inhibition alone. Thus, novel BME inhibitors must display no activity against APP to avoid angioedema risk due to high prevalence of ACE inhibitor therapy in patients with diabetes and cardiovascular disease. [ABSTRACT FROM AUTHOR]

Abstract: The purpose of this study was to identify the mechanism(s) of omapatrilat degradation observed during dissolution from modified release (MR) tablet formulations containing colorants. The tablets were manufactured by a dry granulation process employing roller compaction. The colorants were added intragranularly and included red and yellow iron oxides and FD&C Blue No. 2 lake and dye. Dissolution studies in pH 6 or 6.8 media do not indicate any omapatrilat degradation in the absence of colorants. In the presence of colorants the degradation rate of omapatrilat in pH 6.8 media was in the following order: blue lake>blue lake+yellow iron oxide>yellow and red iron oxides. Higher degradation was observed with MR tablets formulated with indigo carmine (dye) as opposed to tablets formulated with aluminum oxide or aluminum hydroxide (dye substrate portion of lake). The inclusion of tartaric acid and the photostabilizer, uric acid, in omapatrilat MR tablets containing the blue lake reduced the degradation significantly. The dissolution instability observed at pH 6.8 in the MR tablet formulated with FD&C Blue No. 2 Lake was attributed to the dye component of the lake. The instability was more pronounced at higher pH and in the absence of a photostabilizer. [Copyright &y& Elsevier]

Abstract: The objective of this study was to determine whether adrenomedullin, a vasodilator peptide, modulates the process of cell death in cardiomyocytes and whether its effect would be enhanced by the endopeptidase inhibitor omapatrilat, which reduces adrenomedullin degradation. Further, we sought to determine whether the effect of adrenomedullin involved an action to preserve mitochondrial transmembrane potential (ΔΨ m). Cardiomyocytes in culture were treated with agents that interrupted the mitochondrial electron transport chain, inhibiting glycolysis and oxidative phosphorylation. Cell death was evaluated by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay and ΔΨ m was assessed by fluorescent microscopy. Cytochrome c loss from mitochondria and appearance in cytosol was determined by Western blotting. Potassium cyanide (KCN) plus deoxyglucose or antimycin A, for 24 h, produced significant (p <0.01) concentration-dependent reductions in cell viability or increases in cell death. Adrenomedullin reduced cell death produced in this manner and the effect of adrenomedullin was enhanced by treatment with omapatrilat. In contrast, there was no additional reduction in cell death by lisinopril treatment. Omapatrilat plus adrenomedullin reduced the KCN plus deoxyglucose-induced increase in cytosolic cytochrome c. A likely mechanism centers on the ability of adrenomedullin plus omapatrilat to prevent the decline in mitochondrial ΔΨ m produced by KCN plus deoxyglucose treatment. In summary, adrenomedullin plus omapatrilat limited the decline in mitochondrial ΔΨ m that accompanies interruption of mitochondrial metabolism and limited the extent of cell death in cardiomyocytes treated with KCN plus deoxyglucose or antimycin. Adrenomedullin plus the endopeptidase inhibitor omapatrilat may be a useful strategy to protect cardiomyocytes from cell death, in conditions associated with impairment of mitochondrial function. [Copyright &y& Elsevier]

Omapatrilat, a vasopeptidase inhibitor, inhibits both neutral endopeptidase and angiotensin-converting enzyme with similar potency. The aim of this study was to investigate whether omapatrilat prevents or reverses cardiovascular remodeling and hypertension in deoxycorticosterone acetate (DOCA)-salt rats. Male Wistar rats (313 ± 2 g, n=114) were uninephrectomized (UNX) with or without further treatment with DOCA and 1% NaCl in the drinking water. Compared with UNX control rats, DOCA-salt rats developed hypertension, cardiovascular hypertrophy, perivascular and interstitial cardiac fibrosis and inflammation, endothelial dysfunction, and the prolongation of ventricular action potential duration within four weeks. The administration of omapatrilat (40 mg/kg/day po) for two weeks commencing two weeks after surgery attenuated the development of cardiovascular hypertrophy, inflammation, fibrosis, and ventricular action potential prolongation. In contrast, omapatrilat treatment did not lower systolic blood pressure nor improve endothelial dysfunction. This study concludes that the renin-angiotensin-aldosterone, natriuretic peptide, and bradykinin systems are directly involved in the pathogenesis of cardiovascular remodeling in the DOCA-salt model of hypertension in rats, which may be independent of their effects on blood pressure. [ABSTRACT FROM AUTHOR]

The objective of the present study was to assess the cardioprotective effect of dual NEP–ACE inhibition in relation to endogenous cardiac bradykinin (BK), its active metabolite des-Arg9-BK, endogenous brain natriuretic peptides (BNP), and cGMP. Rats were treated with the dual metallopeptidase inhibitor, omapatrilat, or the ACE inhibitor, ramipril, for 7 d (1 mg·kg–1·d–1). Hearts were then isolated and subjected to a zero-flow ischemia and reperfusion (except controls), in the absence or presence of either a B2-receptor antagonist (Hoe-140), a B1-receptor antagonist (Lys-Leu8-des-Arg9-BK), or the GC-A/GC-B-receptor antagonist (HS-142-1). Chronic omapatrilat and ramipril increased the amount of endogenous BK collected upon reperfusion, but only ramipril increased that of des-Arg9-BK. Only omapatrilat increased both peak BNP and peak cGMP upon reperfusion, those increases being blocked by Hoe-140. Chronic omapatrilat (but not ramipril) decreased the total noradrenaline and lactate dehydrogenase release during the reperfusion period. Importantly, only omapatrilat improved the functional recovery of the ischemic reperfused heart, with a reduced left ventricular end-diastolic pressure, and improved developed left ventricular pressure. All cardio protective effects of omapatrilat were blocked by Hoe-140 and by HS-142-1, but not by the B1-receptor antagonist. In conclusion, a chronic treatment with a dual metallopeptidase inhibitor demonstrated a cardioprotective action not observed with an ACE inhibitor in a context of severe ischemia in rat isolated hearts, which was mediated by both endogenous BK and BNP. [ABSTRACT FROM AUTHOR]

Omapatrilat inhibits neutral endopeptidase (NEP) and angiotensin-converting enzyme (ACE). We compared the effects of omapatrilat (40 mg/kg/day, p.o.) to fosinopril (40 mg/kg/day, p.o.) on flow-induced vascular remodeling in New Zealand genetically hypertensive (GH) rats. Both drugs equally reduced blood pressure (BP) initially, but systolic BP and pulse pressure were reduced more by omapatrilat after 1 week. Carotid remodeling was induced by partial ligation of the left common carotid artery (LCA). There was little remodeling in untreated GH rats – measured as outer diameter to body weight (OD/BW vs. before ligation): 97 ± 1% of initial LCA (low flow) and 107 ± 3% of initial right common carotid artery (RCA, high flow). In contrast, OD/BW increased to 118 ± 5% (p < 0.05) of initial RCA after omapatrilat versus 108 ± 2% (p = 0.96) after fosinopril. The major change was increased RCA lumen area which was significantly larger in omapatrilat-treated animals (127% vs. control) than fosinopril-treated animals (103% vs. control). The increase in outward remodeling after omapatrilat treatment correlated weakly with vascular cGMP levels and decreased systolic BP. The results suggest that dual inhibition of NEP/ACE may have greater effects than ACE inhibition alone on vessel remodeling in hypertension. Copyright © 2004 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Vasopeptidase inhibitors simultaneously inhibit both angiotensin-converting enzyme (ACE) and neutral endopeptidase (NEP). The aim of this study was to determine the cardiorenal effects of the vasopeptidase inhibitor omapatrilat in the transgenic m(Ren-2)27 rat which exhibits fulminant hypertension and severe organ pathology. At 6 weeks of age, male Ren-2 rats were randomized to receive no treatment (N = 10), the ACE inhibitor fosinopril 10 mg/kg/day (N = 10), or omapatrilat 10 mg/kg/day (N = 10) or 40 mg/kg/day (N = 10) by daily gavage for 24 weeks. Various cardiorenal functional and structural parameters were assessed. Compared to controls, all treatment groups reduced hypertension in control Ren-2 rats, with both doses of omapatrilat reducing systolic blood pressure significantly more than fosinopril (control, 178 ± 3 mmHg; fosinopril 10 mg/kg/day, 130 ± 4 mmHg; omapatrilat 10 mg/kg/day, 110 ± 3 mmHg; omapatrilat 40 mg/kg/day, 91 ± 3 mmHg). Omapatrilat dose-dependently reduced cardiac hypertrophy, caused a greater inhibition of renal ACE than fosinopril, and was the only treatment to inhibit renal NEP. Attenuation of albuminuria, glomerulosclerosis and cardiorenal fibrosis occurred to a similar degree with omapatrilat and fosinopril. Omapatrilat confers cardiorenal protection in the hypertensive Ren-2 rat. Although inhibition of tissue NEP may contribute to the superior blood pressure reduction by omapatrilat, overall, the results are consistent with the central role that angiotensin II plays in renal and cardiac fibrosis in this model of hypertension. [ABSTRACT FROM AUTHOR]

Omapatrilat inhibits both angiotensin-converting enzyme (ACE) and neutral endopeptidase (NEP). ACE inhibitors have been shown to inhibit atherosclerosis in apoE-deficient mice and in several other animal models but failed in low-density lipoprotein (LDL) receptor-deficient mice despite effective inhibition of the renin-angiotensin-aldosterone system. The aim of the present study was to examine the effect of omapatrilat on atherogenesis in diabetic and nondiabetic LDL receptor-deficient mice. LDL receptor-deficient male mice were randomly divided into 4 groups (n = 11 each). Diabetes was induced in 2 groups by low-dose STZ, the other 2 groups served as nondiabetic controls. Omapatrilat (70 mg/kg/day) was administered to one of the diabetic and to one of the nondiabetic groups. The diabetic and the nondiabetic mice were sacrificed after 3 and 5 weeks, respectively. The aortae were examined and the atherosclerotic plaque area was measured. The atherosclerotic plaque area was significantly smaller in the omapatrilat-treated mice, both diabetic and nondiabetic, as compared to nontreated controls. The mean plaque area of omapatrilat-treated nondiabetic mice was 9357 ± 7293 μm 2 , versus 71977 ± 34610 μm 2 in the nontreated mice ( P = .002). In the diabetic animals, the plaque area was 8887 ± 5386 μm 2 and 23220 ± 10400 μm 2 , respectively for treated and nontreated mice ( P = .001). Plasma lipids were increased by omapatrilat: Mean plasma cholesterol in treated mice, diabetic and nondiabetic combined, was 39.31 ± 6.00 mmol/L, versus 33.12 ± 7.64 mmol/L in the nontreated animals ( P = .008). The corresponding combined mean values of triglycerides were 4.83 ± 1.93 versus 3.00 ± 1.26 mmol/L ( P = .02). Omapatrilat treatment did not affect weight or plasma glucose levels. Treatment with omapatrilat inhibits atherogenesis in diabetic as well as nondiabetic LDL receptor-deficient mice despite an increase in plasma lipids, suggesting a direct effect on the arterial wall. [ABSTRACT FROM AUTHOR]

At the American College of Cardiology in March two major trials were presented. The publicity surrounding the two could not have been more different. The LIFE demonstrated clear superiority of losartan-based therapy over atenolol-based therapy for the treatment of hypertension. It was published the same week in the Lancet and received major press coverage all over the world.The OVERTURE (Omapatrilat Versus Enalapril Randomized Trial of Utility in Reducing Events) study in contrast received a subdued reception, very little publicity and is yet to be published. 5770 NYHA class II–IV heart failure patients (LVEF≤30%, recent heart failure hospital admission) were randomised and uptitrated to either 10 mg BD of Enalapril or 40 mg once a day Omapatrilat. The primary end-point of all cause mortality or heart failure related hospitalisation did not differ significantly: 914/2884 for Enalapril and 914/2886 for Omapatrilat (hazard ratio 0.94, CI’s 0.86–1.03, P=0.187) . Mortality was also similar: 509 for Enalapril and 477 for Omapatrilat (hazard ratio 0.94, CI’s 0.83–1.07, P=0.339). Omapatrilat was as good as Enalapril but not better. The worrying trend was however, that angioedema was more common with Omapatrilat; 24 (0.8%) versus 14 cases (0.5%).The OCTAVE (Omapatrilat Cardiovascular Treatment Assessment Versus Enalapril) study was also presented at this time. 25,267 hypertensives were randomised to Omapatrilat or enalapril and a difference of approximately 3 mmHg in favour of Omapatrilat was seen. Significantly more cases of angioedema were seen with Omapatrilat, 274 (2.17%) compared to 86 (0.68%) with enalapril. Overall death rates were similar, 0.18% for enalapril and 0.15% for Omapatrilat. All adverse events were similar, 51.0% for Omapatrilat and 50.4% for enalapril. The rates of angioedema were much higher in blacks, 5.54% for Ompatrilat and 1.62% for enalapril and for smokers, 3.93% for Omapatrilat and 0.81% for enalapril. We were left with a drug that was, for heart failure, not superior to an ACE inhibitor already off patent, and, as an anti-hypertensive, with an angioedema rate more than double that of an ACE inhibitor in a large head to head comparison. The medical community will be watching to make sure these data are published in full in the medical literature in a timely fashion, in the order of end-points specified in the protocol and with appropriate emphasis on the logical points of presentation. [ABSTRACT FROM AUTHOR]

Background: Omapatrilat, a new vasopeptidase inhibitor, inhibits the activity of angiotensin-converting enzyme (ACE) and neutral endopeptidase 24.11 (NEP). Because these two enzymes participate in the degradation of the vasodilator and natriuretic peptide, angiotensin-(1-7) [Ang-(1-7)], we assessed whether omapatrilat treatment is associated with changes in the plasma and urinary excretion rates of the angiotensins.Methods: We investigated in spontaneously hypertensive rats (SHR) (0.24 kg body weight) the effect of omapatrilat on plasma and urinary concentrations of angiotensin (Ang) I, Ang II and Ang-(1-7) during 17 days of administration of either the drug (N = 15, 100 micromol/kg/day) or vehicle (N = 14) in the drinking water. Hemodynamic and renal excretory function studies were associated with histological examination of the expression of Ang-(1-7) in the kidneys of both vehicle and omapatrilat-treated SHRs.Results: Omapatrilat induced a sustained lowering of systolic blood pressure (-68 mm Hg) without changes in cardiac rate. The mild positive water balance produced by omapatrilat did not cause natriuresis or kaliuresis, although it was associated with a significant decrease in urine osmolality. Blood pressure normalization was accompanied by increases in plasma Ang I (2969%), Ang II (57%), and Ang-(1-7) (163%) levels, paralleling pronounced increases in urinary excretion rates of Ang I and Ang-(1-7) but not Ang II. Detection of Ang-(1-7) immunostaining in the kidneys of five other SHR exposed either to vehicle (N = 3) or omapatrilat (N = 2) ascertained the source of the Ang-(1-7) found in the urine. Intense Ang-(1-7) staining, more pronounced in omapatrilat-treated SHR, was found in renal proximal tubules throughout the outer and inner regions of the renal cortex and the thick ascending loop of Henle, whereas no Ang-(1-7)-positive immunostaining was found in glomeruli and distal tubules.Conclusions: Omapatrilat antihypertensive effects caused significant activation of the renin-angiotensin system associated with increases in urinary excretion rates of Ang I and Ang-(1-7). Combined studies of Ang-(1-7) metabolism in urine and immunohistochemical studies in the kidney revealed the existence of an intrarenal source, which may account for the pronounced increase in the excretion rate of the vasodilator heptapeptide. These findings provide further evidence for a contribution of Ang-(1-7) to the regulation of renal function and blood pressure. [ABSTRACT FROM AUTHOR]

Objective: To assess the effects of omapatrilat, fosinopril and placebo on blood pressure, plasma insulin, glucose and triglycerides concentrations in Zucker rats, a model for insulin resistance. Design: Double blind, parallel, prospective trial. Methods: Forty-two male obese Zucker ( fa / fa ) rats (aged 13-18 week) initially weighing 400-600 g were used for the experiments. Omapatrilat ( n = 14), placebo ( n = 14) or fosinopril ( n = 14) were administrated once daily at 10 µmol/kg oral for 15 days. At baseline and at the end of the study, a tail-cuff blood pressure measurement was performed; an oral glucose tolerance test was done at the end of the study. Results: Omapatrilat and fosinopril resulted in significant lower systolic blood pressure compared to the placebo group ( p < 0.001). This parameter was significantly lower in the omapatrilat group compared with fosinopril-treated rats (116 ±9 vs 125 ±4 mmHg, p < 0.05). After an overnight fast, there was no difference in the fasting glucose concentrations among treatment groups. The basal and post-glucose challenge insulin concentrations were lower in the omapatrilat group compared to the placebo group. No difference was observed in the fasting triglycerides concentrations between the treatment groups. Conclusions: Compared to placebo and fosinopril treatment, omapatrilat results in lower arterial blood pressure in an animal model of insulin resistance. The results suggest that omapatrilat may have a positive effect on insulin sensitivity. [ABSTRACT FROM AUTHOR]

This is a summary of reports of presentation made at the American College of Cardiology 49th Scientific Sessions, Anaheim, 12–15 March 2000. Studies with a particular interest for heart failure physicians have been reviewed. OPTIME-CHF: Outcomes of a Prospective Trial of Intravenous Milrinone for Exacerbations of Chronic Heart Failure. OPTIME-CHF was a randomised-controlled trial comparing a 48-h infusion of Milrinone or standard therapy in 951 patients recruited over a 2-year period. Patients were excluded if the investigator believed their clinical condition mandated inotropic therapy. Patients were randomised within 48 h of admission for an acute exacerbation of chronic heart failure to receive Milrinone or placebo infision for 48 h. Of the patients 43% were diabetics, 70% were receiving an angiotensin converting enzyme inhibitor, 25% were already on a beta-Blocker, and 34% had atrial fibrillation. There was no significant difference between the two groups in length of hospital stay during the index admission, subsequent readmissions and days in hospital over the following 60 days. Subjective clinical assessment scores were also no different. There was an average admission rate over the next year of one per patient in both groups. However, there was a significant increase in the incidence of sustained hypotension in the Milrinone group, which accounted for all of the increased adverse event rates for the active therapy. The 60-day mortality was 10% in both groups. This and previous trials of the oral formulation of Milrinone have now clearly demonstrated a lack of benefit with Milrinone in either during acute exacerbations of or in stable severe chronic heart failure [Packer M, Carver JR, Rodeheffer RJ et al. Effect of oral Milrinone on mortality in severe chronic heart failure. N Engl J Med 1991;325:1468–1475.]. Medium sized studies of Milrinone in patients with milder severities of heart failure also suggested an adverse impact on prognosis in the presence or absence of digoxin [DiBianco R, Shabetai R, Kostuk W, Moran J, Schlant RC, Wright R. A comparison of oral Milrinone, digoxin, and their combination in the treatment of patients with chronic heart failure. N Engl J Med 1989;320:677–683.]. Whether Milrinone even has a role for the management of a haemodyamic crisis requiring inotropic therapy must also be questioned. [ABSTRACT FROM PUBLISHER]

Omapatrilat is an antagonist of angiotensin-converting (ACE) and neprilysin-neuropeptidase (NEP) enzymes. The aim of our study is to show that omapatrilat may have beneficial effects as a treatment for polymicrobial sepsis. A cecal ligation and puncture (CLP) sepsis model was used to evaluate 10 and 20 mg/kg doses of omapatrilat in mice (n = 30) fasted for 12 h. The lungs were removed 12 h after CLP, and lung levels of cytokines (tumor necrosis factor-alpha [TNF-α], interleukin-6 [IL-6], NF-κB), iNOS and eNOS mRNA expression, GSH and MDA levels, and ACE and NEP activities were determined. Histopathological examinations were also performed. Omapatrilat treatment provided a dose-dependent reduction in oxidative stress and inflammatory parameters in lung tissues. Omapatrilat administration decreased lung iNOS and eNOS mRNA levels at 20 mg/kg dose. Histopathological analysis revealed a decline in the thickening and edema areas in the alveolar septa in the Sepsis+OMA20 group. Omapatrilat, a dual ACE and NEP inhibitor, protected lung tissue from sepsis damage by reducing ACE and NEP activities, by decreasing the mRNA expression levels of pro-inflammatory cytokines (TNF-α, IL-6, and NF-κB), by suppressing leukocyte infiltration and edema, by restoring iNOS and eNOS levels, and by restoring SOD activity and GSH and MDA levels, thereby reducing oxidative stress. [ABSTRACT FROM AUTHOR]