Severe Hypotension With Concomitant Sodium-Glucose Co-Transporter-2 Inhibitor and Angiotensin Receptor-Neprilysin Inhibitor Therapy in a Patient With Heart Failure Reduced Ejection Fraction: A Case Report

Background: Large cardiovascular outcomes trials in individuals with heart failure, with and without diabetes, have demonstrated a significant risk reduction in the composite outcome of cardiovascular death or hospitalizations for heart failure with SGLT2 inhibitor therapy. These positive outcomes have led to the recommendation that SGLT2 inhibitors serve as backbone therapy in patients with heart failure reduced ejection fraction (HFrEF). To date, there has not been enough participants in clinical trials on concomitant SGLT2 inhibitor and angiotensin receptor-neprilysin inhibitor therapy to evaluate the benefits and risks of combination therapy with these two agents outside of smaller subgroup analyses. Case Summary: This case describes a Black female with diabetes meeting her glycemic targets and concomitant stable NYHA FC II HFrEF on guideline-directed medical therapy (GDMT) with sacubitril/valsartan, spironolactone and metoprolol succinate who developed severe hypotension and dehydration requiring hospitalization after initiation of SGLT2 inhibitor therapy. Practice Implications: This case report raises the question of whether those with type 2 diabetes, and/or those on background angiotensin receptor-neprilysin inhibitor therapy, who are euvolemic or sensitive to diuretic therapy should be started on lower dose dapagliflozin and titrated to 10 mg daily based on response. It also raises awareness to the potential increased diuretic effect produced with concomitant use of sacubitril/valsartan and dapagliflozin. Caution and education to mitigate the risk for volume depletion should be provided to those patients who are euvolemic and initiated on a SGLT2 inhibitor, regardless of their background diuretic and GDMT. Conclusion: Future research should focus on the benefits and safety considerations and provide education on how to best initiate and adjust SGLT2 inhibitors in the setting of sacubitril/valsartan use in diverse heart failure patient populations.

Use of Sodium-Glucose Cotransporter-2 Inhibitors and Angiotensin Receptor-Neprilysin Inhibitors in Patients With Atrial Fibrillation and Heart Failure From 2021 to 2022: An Analysis of Real-World Data

BACKGROUND

Contemporary use of sodium-glucose cotransporter-2 inhibitors (SGLT2i) and angiotensin receptor-neprilysin inhibitors (ARNi) in patients with atrial fibrillation (AF) and heart failure (HF) has not been described.

METHODS AND RESULTS

We analyzed the MarketScan databases for the period January 1, 2021 to July 30, 2022. Validated algorithms were used to identify patients with AF and HF, and to classify patients into HF with reduced ejection fraction (HFrEF) or HF with preserved ejection fraction (HFpEF). We assessed the prevalence of SGLT2i and ARNi use overall and by HF type. Additionally, we explored correlates of lower use, including demographics and comorbidities. The study population included 60 927 patients (mean age, 75 years; 43% women) diagnosed with AF and HF (85% with HFpEF, 15% with HFrEF). Prevalence of ARNi use was 11% overall (30% in HFrEF, 8% in HFpEF), whereas the corresponding figure was 6% for SGLT2i (13% in HFrEF, 5% in HFpEF). Use of both medications increased over the study period: ARNi from 9% to 12% (22%-29% in HFrEF, 6%-8% in HFpEF), and SGLT2i from 3% to 9% (6%-16% in HFrEF, 2%-7% in HFpEF). Female sex, older age, and specific comorbidities were associated with lower use of these 2 medication types overall and by HF type.

CONCLUSIONS

Use of ARNi and SGLT2i in patients with AF and HF is suboptimal, particularly among women and older individuals, though use is increasing. These results underscore the need for understanding reasons for these disparities and developing interventions to improve adoption of evidence-based therapies among patients with comorbid AF and HF.

Angiotensin-Neprilysin inhibition in heart failure with preserved ejection fraction: A meta-analysis of randomized controlled trials

BACKGROUND

The effect of sacubitril/valsartan on patients with heart failure (HF) with preserved ejection fraction (HFpEF) is a topic of ongoing debate.

METHODS

Medline was queried from inception through the last week of May 2023 for randomized studies assessing the effects of sacubitril/valsartan in patients with HFpEF. For continuous outcomes, we pooled either the geometric mean ratios (gMR) or weighted mean difference (WMD) with 95% confidence intervals (CI). For dichotomous outcomes, we pooled Risk ratios (RR) with 95% CI.

RESULTS

Four trials were included (N=8,129). Compared to the control, sacubitril/valsartan was associated with a reduction in NT-proBNP levels (gMR: 0.84, 95% CI 0.80, 0.88) and improvement in KCCQ score (WMD: 0.85, 95% CI: 0.02, 1.67). We observed no differences for HF hospitalization (RR: 0.90, 95% CI: 0.79, 1.01), cardiovascular mortality (RR: 0.83, 95% CI: 0.52, 1.32), all-cause mortality (RR: 0.99, 95% CI: 0.86-1.13) and improvement (RR: 1.15, 95% CI: 0.93, 1.42) or worsening (RR: 0.92, 95% CI: 0.78, 1.09) of NYHA class between the sacubitril/valsartan and comparator group. Sacubitril/valsartan was generally safe, and patients were less likely to have a ≥50% decline in eGFR compared to control (RR: 0.60, 95% CI: 0.39, 0.92).

CONCLUSION

Pooled analysis suggests that sacubitril/valsartan reduces natriuretic peptide levels and improves the quality of life in patients with HFpEF, which may translate into better clinical outcomes as observed by a numerical trend towards improvement in major HF outcomes with sacubitril/valsartan therapy.

Knowledge domain and emerging trends in sacubitril/valsartan study from 2008 to 2023 - a visualized conclusive analysis based on novel scientometric tools

OBJECTIVE

This study aimed to determine the evolution of sacubitril-valsartan research and analyze the publications quantitatively and qualitatively.

MATERIALS AND METHODS

We used the bibliometric method and a combination of CiteSpace_6.1.6 and VOSviewer_1.6.18 to identify top authors, countries, institutions, co-cited articles, co-cited journals, keywords, and trends. This study prioritized key aspects in the existing global research on Entresto (Sacubitril/Valsartan) to assess our depth of knowledge in this field and identify potential insights. The objective was to generate a reference for the utilization of the "angiotensin receptor-neprilysin inhibitor" (ARNI).

RESULTS

From 2008 to 2022, citations of sacubitril-valsartan showed an upward trend. VOSviewer keyword analysis of 3,408 publications identified 624 keywords and divided them into seven different clusters. The clustered network was constructed based on 1,191 references cited by 3,408 publications that met the terms, where the clustered network of sacubitril-valsartan was presented. These publications can be regarded as fundamental to Entresto's research. Analysis of co-cited reference clusters showed that other than Entresto's novel application in other diseases, the new combination with other medication or mechanical assistance therapies against heart failure was Entresto's latest focus. Analysis of citation bursts showed that the rank of the top 25 keywords, according to the chronological sequence, marked Entresto's research entering a new era of exploring the extended application in other diseases and novel combinations with other diverse therapies.

CONCLUSIONS

We found that emerging new mechanisms in sacubitril-valsartan therapy intended for more targets in the pathogenesis of specific diseases will be the focus of further studies.

Patient-Centered Heart Failure Therapy

Simultaneous initiation of quadruple therapy with angiotensin receptor-neprilysin inhibitor, beta-adrenergic receptor blocker, mineralocorticoid receptor antagonist, and sodium glucose cotransporter 2 inhibitor aims at prompt improvement and prevention of readmission in patients hospitalized for heart failure with reduced ejection fraction. However, titration of quadruple therapy is time consuming. Lengthy up-titration of quadruple therapy may negate the benefit of early initiation. Quadruple therapy should start with a sodium glucose cotransporter 2 inhibition and a mineralocorticoid antagonist, as both enable safe decongestion and require minimal or no titration. Depending on the level of decongestion and clinical characteristics, patients receive an angiotensin receptor-neprilysin inhibitor or a beta-adrenergic receptor blocker to be titrated after hospital discharge. Outpatient addition of an angiotensin receptor-neprilysin inhibitor to a beta-adrenergic receptor blocker or vice versa completes the quadruple therapy scheme. By focusing on decongestion and matching intervention to patients' profile, the present therapeutic sequence allows rapid implementation of quadruple therapy at fully recommended doses.

Evaluation of the clinical efficacy of racecadotril in the treatment of neonatal calves with infectious diarrhea

Racecadotril, used as an antidiarrheal drug in humans and some animals such as the dog, inhibits peripheral enkephalinase, which degrades enkephalins and enkephalinase inhibition induces a selective increase in chloride absorption from the intestines. The study material consisted of 46 calves with infectious diarrhea and 14 healthy calves in the age 2-20 days. The calves were divided into eight groups; healthy calves (HG), healthy calves administered racecadotril (HRG), calves with E.coli-associated diarrhea (ECG), calves with E.coli-associated diarrhea administered racecadotril (ECRG), calves with bovine Rotavirus/Coronavirus-associated diarrhea (VG), calves with bovine Rotavirus/Coronavirus-associated diarrhea administered racecadotril (VRG), calves with C. parvum-associated diarrhea (CG) and calves with C. parvum-associated diarrhea administered racecadotril (CRG). Calves in the racecadotril groups received oral racecadotril at a dose of 2.5 mg/kg twice a day for 3 days. A routine clinical examination of all calves was performed. Hemogram and blood gas measurements were made from the blood samples. Standard diarrhea treatment was applied to the HG, ECG, CG, and VG groups. Clinical score parameters such as appetite, feces quality, dehydration, standing and death and some blood gas and hemogram parameters were evaluated to determine the clinical efficacy of racecadotril. Clinical score parameters were determined observationally. Blood gas measurements were performed using a blood gas analyzer. The hemogram was performed using an automated hematologic analyzer. Statistically significant differences were determined in the blood pH, bicarbonate, base deficit, lactate, and total leukocyte count in calves with diarrhea compared to healthy calves. After the treatments, these parameters were found to be within normal limits. At the end of treatment, 42 of the 46 diarrheal calves recovered, while 4 died. We found that racecadotril was effective in improving both clinical recovery and feces consistency in neonatal calves with diarrhea caused by E. coli. As a result, it can be stated that racecadotril, which has an antisecretory effect, is beneficial in the treatment of bacterial diarrhea caused by such as E. coli.

Comparison of the effects of angiotensin receptor-neprilysin inhibitors and thiazide diuretic/renin-angiotensin system inhibitor combination therapy in hypertensive patients: a retrospective cohort study

Angiotensin receptor-neprilysin inhibitors (ARNIs) have been approved as antihypertensive agents in Japan, and thiazide diuretics (TZDs) are widely used concomitantly with renin-angiotensin system inhibitors (RASIs) for hypertension. This retrospective study included patients with hypertension who switched from RASI to ARNI therapy (ARNI group) and those who were prescribed TZDs with RASIs (TZD/RASI group). Drug-related changes in the estimated glomerular filtration rate (eGFR), blood pressure (BP), body weight (BW), serum electrolytes, uric acid (UA), and triglyceride levels were compared between the two groups. Overall, 70 participants (31 and 39 in the ARNI and TZD/RASI groups, respectively) were enrolled and observed for a median of 2 months. According to linear mixed models, compared with the TZD/RASI group, the ARNI group exhibited a significant change in mean eGFR of 3.71 mL/min/1.73 m2 [95% confidence interval (CI), 0.57-6.84; P = 0.02] from the time of switching drug to the next outpatient visit. Further, compared with the TZD/RASI group, the ARNI group exhibited significant changes in mean serum UA (-1.27; 95% CI, -1.66 to -0.88), sodium (1.22; 95% CI, 0.12 to -2.32), chloride (2.14; 95% CI, 0.75-3.52), and triglyceride (-52.1; 95% CI, -100.9 to -3.29) levels. Conversely, serum potassium levels, BW, and systolic and diastolic BP did not differ significantly between the two groups (P = 0.69, 0.44, 0.49, and 0.66, respectively). Compared with the combination therapy of TZD and RASI, ARNI therapy causes less renal dysfunction, hyperuricemia, and hypertriglyceridemia with fewer electrolyte abnormalities and no significant difference in antihypertensive effects.

Health and Economic Evaluation of Sacubitril-Valsartan for Heart Failure Management

Importance

The US Food and Drug Administration expanded labeling of sacubitril-valsartan from the treatment of patients with chronic heart failure (HF) with reduced ejection fraction (EF) to all patients with HF, noting the greatest benefits in those with below-normal EF. However, the upper bound of below normal is not clearly defined, and value determinations across a broader EF range are unknown.

Objective

To estimate the cost-effectiveness of sacubitril-valsartan vs renin-angiotensin system inhibitors (RASis) across various upper-level cutoffs of EF.

Design, Setting, and Participants

This economic evaluation included participant-level data from the PARADIGM-HF (Prospective Comparison of ARNI With ACEI to Determine Impact on Global Mortality and Morbidity in Heart Failure) and the PARAGON-HF (Prospective Comparison of ARNi with ARB Global Outcomes in HF With Preserved Ejection Fraction) trials. PARADIGM-HF was conducted between 2009 and 2014, PARAGON-HF was conducted between 2014 and 2019, and this analysis was conducted between 2021 and 2023.

Main Outcomes and Measures

A 5-state Markov model used risk reductions for all-cause mortality and HF hospitalization from PARADIGM-HF and PARAGON-HF. Quality-of-life differences were estimated from EuroQol-5D scores. Hospitalization and medication costs were obtained from published national sources; the wholesale acquisition cost of sacubitril-valsartan was $7092 per year. Risk estimates and treatment effects were generated in consecutive 5% EF increments up to 60% and applied to an EF distribution of US patients with HF from the Get With the Guidelines-Heart Failure registry. The base case included a lifetime horizon from a health care sector perspective. Incremental cost-effectiveness ratios (ICERs) were estimated at EFs of 60% or less (base case) and at various upper-level EF cutoffs.

Results

Among 13 264 total patients whose data were analyzed, for those with EFs of 60% or less, sacubitril-valsartan was projected to add 0.53 quality-adjusted life-years (QALYs) at an incremental lifetime cost of $40 892 compared with RASi, yielding an ICER of $76 852 per QALY. In a probabilistic sensitivity analysis, 95% of the values of the ICER occurred between $71 516 and $82 970 per QALY. Among patients with chronic HF and an EF of 60% or less, treatment with sacubitril-valsartan vs RASis would be at least of economic intermediate value (ICER <$180 000 per QALY) at a sacubitril-valsartan cost of $10 242 or less per year, of high economic value (ICER <$60 000 per QALY) at a cost of $3673 or less per year, and cost-saving at a cost of $338 or less per year. The ICERs were $67 331 per QALY, $59 614 per QALY, and $56 786 per QALY at EFs of 55% or less, 50% or less, and 45% or less, respectively. Treatment with sacubitril-valsartan in only those with EFs of 45% or greater (up to ≤60%) yielded an ICER of $127 172 per QALY gained; treatment was more cost-effective in those at the lower end of this range (ICER of $100 388 per QALY gained for those with EFs of 45%-55%; ICER of $84 291 per QALY gained for those with EFs of 45%-50%).

Conclusions and Relevance

Cost-effectiveness modeling provided an ICER for treatment with sacubitril-valsartan vs RASis consistent with high economic value for patients with reduced and mildly reduced EFs (≤50%) and at least intermediate value at the current undiscounted wholesale acquisition cost price at an EF of 60% or less. Treatment was more cost-effective at lower EF ranges. These findings may have implications for coverage decisions and value assessments in contemporary clinical practice guidelines.

Frailty and uptake of angiotensin receptor neprilysin inhibitor for heart failure with reduced ejection fraction

BACKGROUND

Frail older adults may be less likely to receive guideline-directed medical therapy (GDMT)-renin-angiotensin blockers, beta-blockers, and mineralocorticoid receptor antagonists-for heart failure with reduced ejection fraction (HFrEF). We aimed to examine the uptake of angiotensin receptor neprilysin inhibitor (ARNI) and GDMT in frail older adults with HFrEF.

METHODS

Using 2015-2019 Medicare data, we estimated the proportion of beneficiaries with HFrEF receiving ARNI and GDMT each year by frailty status, defined by a claims-based frailty index. Logistic regression was used to identify clinical characteristics associated with ARNI initiation. Cox proportional hazards regression was used to examine the association of GDMT use in 2015 and death or heart failure hospitalization in 2016-2019.

RESULTS

Among 147,506-180,386 beneficiaries with HFrEF (mean age: 77 years; 27% women; 42.6-49.1% frail) in 2015-2019, the proportion of patients receiving ARNI increased in both non-frail (0.4%-16.4%) and frail (0.3%-13.7%) patients (p for yearly-trend-by-frailty = 0.970). Among those not receiving a renin-angiotensin system blocker, patients with age ≥ 85 years (odds ratio [95% CI], 0.89 [0.80-0.99]), dementia (0.88 [0.81-0.96]), and frailty (0.87 [0.81-0.94]) were less likely to initiate ARNI. The proportion of patients receiving all 3 GDMT classes increased in non-frail patients (22.0%-27.0%) but changed minimally in frail patients (19.6%-21.8%). Regardless of frailty status, treatment with at least 1 class of GDMT was associated with lower death or heart failure hospitalization than no GDMT medications (hazard ratio [95% CI], 0.94 [0.91-0.97], 0.92 [0.89-0.94], 0.94 [0.91-0.97] for 1, 2, and 3 classes, respectively).

CONCLUSIONS

Our results suggest an evidence-practice gap in the use of ARNI and GDMT in Medicare beneficiaries with HFrEF, particularly those with frailty. Efforts to narrow this gap are needed to reduce the burden of HFrEF in older adults.

Co-administration of dl-3-n-butylphthalide and neprilysin is neuroprotective in Alzheimer disease associated with mild traumatic brain injury

dl-3-n-Butylphthalide is a potent synthetic Chinese celery extract that is highly efficient in inducing neuroprotection in concussive head injury (CHI), Parkinson's disease, Alzheimer's disease, stroke as well as depression, dementia, anxiety and other neurological diseases. Thus, there are reasons to believe that dl-3-n-butylphthalide could effectively prevent Alzheimer's disease brain pathology. Military personnel during combat operation or veterans are often the victims of brain injury that is a major risk factor for developing Alzheimer's disease in their later lives. In our laboratory we have shown that CHI exacerbates Alzheimer's disease brain pathology and reduces the amyloid beta peptide (AβP) inactivating enzyme neprilysin. We have used TiO2 nanowired-dl-3-n-butylphthalide in attenuating Parkinson's disease brain pathology exacerbated by CHI. Nanodelivery of dl-3-n-butylphthalide appears to be more potent as compared to the conventional delivery of the compound. Thus, it would be interesting to examine the effects of nanowired dl-3-n-butylphthalide together with nanowired delivery of neprilysin in Alzheimer's disease model on brain pathology. In this investigation we found that nanowired delivery of dl-3-n-butylphthalide together with nanowired neprilysin significantly attenuated brain pathology in Alzheimer's disease model with CHI, not reported earlier. The possible mechanism and clinical significance is discussed based on the current literature.

Angiotensin-Neprilysin Inhibition in Patients With Mildly Reduced or Preserved Ejection Fraction and Worsening Heart Failure

BACKGROUND

U.S. guidelines recommend consideration of sacubitril/valsartan in chronic heart failure (HF) and mildly reduced or preserved ejection fraction (EF). Whether initiation is safe and effective in EF >40% after a worsening heart failure (WHF) event is unknown.

OBJECTIVES

PARAGLIDE-HF (Prospective comparison of ARNI with ARB Given following stabiLization In DEcompensated HFpEF) assessed sacubitril/valsartan vs valsartan in EF >40% following a recent WHF event.

METHODS

PARAGLIDE-HF is a double-blind, randomized controlled trial of sacubitril/valsartan vs valsartan in patients with EF >40% enrolled within 30 days of a WHF event. The primary endpoint was time-averaged proportional change in amino terminal pro-B-type natriuretic peptide (NT-proBNP) from baseline through Weeks 4 and 8. A secondary hierarchical outcome (win ratio) consisted of: 1) cardiovascular death; 2) HF hospitalizations; 3) urgent HF visits; and 4) change in NT-proBNP.

RESULTS

In 466 patients (233 sacubitril/valsartan; 233 valsartan), time-averaged reduction in the NT-proBNP was greater with sacubitril/valsartan (ratio of change: 0.85; 95% CI: 0.73-0.999; P = 0.049). The hierarchical outcome favored sacubitril/valsartan but was not significant (unmatched win ratio: 1.19; 95% CI: 0.93-1.52; P = 0.16). Sacubitril/valsartan reduced worsening renal function (OR: 0.61; 95% CI: 0.40-0.93) but increased symptomatic hypotension (OR: 1.73; 95% CI: 1.09-2.76). There was evidence of a larger treatment effect in the subgroup with EF ≤60% for NT-proBNP change (0.78; 95% CI: 0.61-0.98) and the hierarchical outcome (win ratio: 1.46; 95% CI: 1.09-1.95).

CONCLUSIONS

Among patients with EF >40% stabilized after WHF, sacubitril/valsartan led to greater reduction in plasma NT-proBNP levels and was associated with clinical benefit compared with valsartan alone, despite more symptomatic hypotension. (Prospective comparison of ARNI with ARB Given following stabiLization In DEcompensated HFpEF; NCT03988634).

Optimal Pharmacologic Treatment of Heart Failure With Preserved and Mildly Reduced Ejection Fraction: A Meta-analysis

IMPORTANCE

In recent years, significant progress has been made in the pharmacologic treatment of heart failure (HF) with reduced ejection fraction (HFrEF), but there is still insufficient evidence for drug therapy for HF with preserved ejection fraction (HFpEF) and mildly reduced ejection fraction (HFmrEF).

OBJECTIVE

To compare the outcomes associated with different drug combinations for the treatment of HFpEF and HFmrEF.

DATA SOURCES

A search of the PubMed, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) databases was conducted for studies published from inception to October 9, 2021.

STUDY SELECTION

Randomized clinical trials on the use of angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), angiotensin receptor-neprilysin inhibitors (ARNIs), mineralocorticoid receptor antagonists (MRAs), β-blockers, and sodium-glucose cotransporter 2 (SGLT2) inhibitors for patients with HFpEF or HFmrEF.

DATA EXTRACTION AND SYNTHESIS

Data extraction and bias assessment were independently performed by 2 reviewers following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guideline. All data for 3 outcomes were pooled with a fixed-effect model.

MAIN OUTCOMES AND MEASURES

The main outcomes were first hospitalization for HF, all-cause mortality, and cardiovascular mortality. Hazard ratios (HRs) and 95% credible intervals (CrIs) were evaluated using a bayesian network meta-analysis model.

RESULTS

In this analysis, 19 randomized clinical trials, including 20 633 patients with HF and an ejection fraction of 40% or more, without a remarkable risk of bias were included. Compared with placebo, no treatments were associated with a significant reduction in the risk of all-cause death or cardiovascular death. SGLT2 inhibitors, ARNIs, and MRAs were associated with a significant decrease in the risk of HF hospitalization compared with placebo (SGLT2 inhibitors: HR, 0.71 [95% CrI, 0.60-0.83]; ARNIs: HR, 0.76 [95% CrI, 0.61-0.95]; MRAs: HR, 0.83 [95% CrI, 0.69-0.99]), and SGLT2 inhibitors were the optimal drug class in terms of reducing the risk for HF admission. Sensitivity analysis results demonstrated a progressive decrease in the risk of HF admission and an advance in mean rank associated with the increasing use of drug classes.

CONCLUSIONS AND RELEVANCE

The findings of this study suggest that SGLT2 inhibitors were the optimal drug class for HFpEF and HFmrEF, consistent with the most recent guideline recommendation. The incremental use of combinations of SGLT2 inhibitors, ACE inhibitors or ARBs, and β-blockers may be associated with accumulative benefits in HF hospitalization rather than all-cause death among patients with HFpEF and HFmrEF.

Valsartan and sacubitril combination treatment enhances collagen production in older adult human skin cells

Collagen is a major component of the skin's support system, allowing for its firmness, elasticity, and mechanical strength. Skin collagen production decreases as we age and is associated with increased sagging, wrinkling, and thinning. The Renin-Angiotensin System (RAS) is a key hormonal system that changes with age and affects multiple organ systems. The primary health benefits of Angiotensin (Ang) receptor type1 (AT1R) blockers are believed to arise from systemic effects on blood pressure. However, there is also a skin-specific RAS, though this system has been less well characterized. There are eight FDA-approved angiotensin receptor blockers (ARBs) on the market, although the impact of topical ARBs on aging skin is unknown. Here, we evaluated the topical penetration of gel formulations of eight ARBs using human cadaver skin. Our results show that valsartan achieved the highest skin penetration compared to other ARBs. We then treated human skin fibroblasts from 2-year-old and 57-year-old individuals with valsartan alone or in combination with the neprilysin inhibitor sacubitril. Sacubitril works synergistically with valsartan by inhibiting the degradation of angiotensin II, thereby increasing its bioavailability. Treatment of young and older adult human skin cells with valsartan and sacubitril led to a five-fold increase in collagen type-1 production in the young cells and a four-fold increase in collagen type-1 in older adult cells. This study demonstrates a potential novel application for the widely prescribed drug combination sacubitril-valsartan as a topical agent in aged skin.

Renin-angiotensin-aldosterone system inhibition in patients affected by heart failure: efficacy, mechanistic effects and practical use of sacubitril/valsartan. Position Paper of the Italian Society of Cardiology

Renin-angiotensin-aldosterone system (RAAS) inhibition is a mainstay of the pharmacological treatment of heart failure with reduced ejection fraction (HFrEF). In the last years RAAS blockade has been improved by the introduction of the Angiotensin Receptor-Neprilysin Inhibitor (ARNI) sacubitril/valsartan, that combines RAAS inhibition with the block of neprilysin, boosting the positive effects of natriuretic peptides. The PARADIGM-HF trial demonstrated a significant advantage of sacubitril/valsartan over enalapril on the reduction of cardiovascular (CV) mortality and heart failure hospitalizations rates. Then, several randomized clinical trials and observational studies investigated its role in different clinical settings and its efficacy has been fully recognized in the most recent HFrEF European and USA guidelines. The effects of sacubitril/valsartan on major CV outcomes are associated with reduction of NT-proBNP levels and reverse cardiac remodeling and mitral regurgitation, recognized as one of the mechanistic effects of the drug explaining the favorable prognostic effects. A careful evaluation of patients' clinical profile is relevant to implement the use of ARNI in the clinical practice and to obtain the maximal treatment efficacy. The present Position Paper reports the opinion of the Italian Society of Cardiology on the optimal blockade of the RAAS system in HF patients with the aim of fostering widespread implementation of scientific evidence and practice guidelines in the medical community.

Pharmacological Anti-Remodelling Effects of Disease-Modifying Drugs in Heart Failure with Reduced Ejection Fraction

Cardiac remodelling is an adverse phenomenon linked to heart failure progression and an important contributor to heart failure severity. Cardiac remodelling could represent the real therapeutic goal in the treatment of patients with heart failure with reduced ejection fraction, being potentially reversed through different pharmacotherapies. Currently, there are well-established drugs such as angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers and β-blockers with anti-remodelling effects; recently, angiotensin receptor neprilysin inhibitor effects on inhibiting cardiac remodelling (improving N-terminal pro-B-type natriuretic peptide levels, echocardiographic parameters of reverse cardiac remodelling and right ventricular function in patients with heart failure with reduced ejection fraction) were demonstrated. More recently, hemodynamic consequences of gliflozins, reduced cardiac hydrostatic pressure as a possible cause of ventricular remodelling and hypertrophy were proposed to explain potential anti-remodelling effects of gliflozins. Gliflozins exert their cardioprotective effects by attenuating myofibroblast activity and collagen-mediated remodelling. Another postulated mechanism is represented by the reduction in sympathetic activity, through the reduction in renal afferent nervous activity and the suppression of central reflex mechanisms. Benefits of gliflozins on left ventricular hypertrophy, dilation, and systolic and diastolic function were also described. In this review, we aimed to provide a wide overview on cardiac remodelling with a particular focus on possible anti-remodelling effects of angiotensin receptor neprilysin inhibitors and gliflozins.

[Angiotensine Receptor-Neprilysin Inhibitor combination is not the preferred medication for patients after acute myocardial infarction]

The PARADISE-MI study compared standard treatment with an ACE inhibitor (ramipril) after an acute myocardial infarction with the newer sacubitril/ valsartan combination (so-called ARNI) medication in 5661 patients. Most patients had a reduced cardiac function (40% ejection fraction or less) and in about 50% of patients it was accompanied by complaints of congestion. The expected 15% reduction in primary endpoint cardiovascular death or rehospitalization or extra visits for heart failure was not met after 22 months. The study is characterized by an increased incidence of symptomatic hypotension of 28,3% in the group treated with the ARNI, compared to an incidence of 21,9% in the group treated with the ACE inhibitor. The interpretation of the trial is hampered by the mixed design of prevention and treatment trial for heart failure. A continuing careful approach is advised with ACE inhibitors as first choice in the first week(s) after myocardial infarction.

Acute Tubular Necrosis Associated with Angiotensin Receptor-neprilysin Inhibitor

Sacubitril/valsartan, an angiotensin receptor-neprilysin inhibitor (ARNI), significantly reduces mortality and morbidity in patients with chronic heart failure with a reduced ejection fraction (HFrEF). However, a considerable number of patients treated with sacubitril/valsartan experience hypotension, oliguria, progressive azotemia, and renal failure as adverse events. These issues have been linked to significant gaps in the usage and dosing of guideline-directed medical therapy with ARNI in patients with HFrEF. We herein report a relevant case of pathologically proven acute tubular necrosis after the first dose of sacubitril/valsartan, highlighting the importance of optimizing the medical therapy in an outpatient with HFrEF.

Treatment with angiotensin receptor neprilysin inhibitor for Taiwan heart failure patients: Rationale and baseline characteristics of the TAROT-HF study

BACKGROUND

This study used a real-world database to investigate the prescription patterns of sacubitril/valsartan (Sac/Val) among Taiwanese patients with heart failure with reduced ejection fraction (HFrEF).

METHODS

The Treatment with Angiotensin Receptor neprilysin inhibitor fOr Taiwan Heart Failure patients (TAROT-HF) study is a principal investigator-initiated, multicenter, observational, retrospective study on Taiwanese HFrEF patients. A total of 1772 patients with HFrEF (mean age 62.5 years, 75.3% male, mean left ventricular ejection fraction [LVEF] 29.3%) who received Sac/Val at 10 hospitals between 2017 and 2018 were enrolled at the date of Sac/Val initiation. Among these patients, 585 (33%) initially received Sac/Val during acute decompensated heart failure (HF) hospitalization (TAROT-AHF arm), whereas 1187 (67%) initially received the same at the outpatient clinic (TAROT-CHF arm).

RESULTS

A total of 1343 (75.8%) patients received an initial dose of 50 mg twice daily or fewer, whereas 422 (23.8%) received the standard initiation dose (100 mg twice daily). During outpatient Sac/Val initiation, the mean dosages were significantly higher than that following hospitalization (117 ± 55 mg vs 109 ± 57 mg; p = 0.014). Multivariate analysis identified younger age, higher systolic blood pressure, higher LVEF, prior use of renin-angiotensin system inhibitors, use of ivabradine, and a history of diabetes mellitus as independent factors for initiating a standard Sac/Val dose. Over a follow-up period of 18 months, incidences of cardiovascular death or first unplanned HF hospitalization were 18.69 and 33.11 per 100-person years for the TAROT-CHF and TAROT-AHF arms, respectively.

CONCLUSION

The TAROT-HF study provided an opportunity to describe the clinical features of patients with HFrEF who received Sac/Val, assess the real-world utilization and efficacy of Sac/Val, and compare these patients with those included in prior registries.

Sacubitril/Valsartan: Neprilysin Inhibition 5 Years After PARADIGM-HF

Sacubitril/valsartan, an angiotensin receptor-neprilysin inhibitor (ARNI), has been shown to reduce the risk of cardiovascular death or heart failure hospitalization and improve symptoms among patients with chronic heart failure with reduced ejection fraction compared to enalapril, the gold standard angiotensin-converting enzyme inhibitor. In the 5 years since the publication of the results of PARADIGM-HF, further insight has been gained into integrating a neprilysin inhibitor into a comprehensive multidrug regimen, including a renin-angiotensin aldosterone system (RAS) blocker. This paper reviews the current understanding of the effects of sacubitril/valsartan and highlights expected developments over the next 5 years, including potential new indications for use. Additionally, a practical, evidence-based approach is provided to the clinical integration of sacubitril/valsartan among patients with heart failure with reduced ejection fraction.

Comparison of Hydralazine/Nitrate and Angiotensin Receptor Neprilysin Inhibitor Use Among Black Versus Nonblack Americans With Heart Failure and Reduced Ejection Fraction (from CHAMP-HF)

Underuse of hydralazine/nitrate (HYD/NIT) in black patients with heart failure and reduced ejection fraction (HFrEF) has been previously described, but whether this important treatment gap persists in contemporary practice is unknown. Sacubitril/valsartan has become a part of guideline-directed medical therapy for HFrEF but data on utilization of this therapy in black patients is lacking. This study addressed these issues by assessing the frequency of HYD/NIT and sacubitril/valsartan use in black patients with HFrEF in the Change the Management of Patients with Heart Failure Registry, a multicenter cohort study. The association of race with utilization rates of these agents was also evaluated. Clinical and medication data at baseline and during 12 months of follow-up from black and nonblack registry patients without documented contraindications or intolerance to the medications of interest were analyzed. Data were available from December 2015 to October 2017, in 4,848 HFrEF patients, of whom 853 were black (18%) and 3995 were nonblack. Black patients were younger, more likely to be female, and had lower ejection fractions compared with nonblacks. Only 11% of black patients were receiving HYD/NIT therapy at baseline and 13% at 1 year. The percentage of black patients treated at baseline with sacubitril/valsartan was also low at 18% and remained unchanged at 1 year. After adjustment for covariates, race was independently associated with HYD/NIT use (odds ratio 8.32; 95% confidence interval 6.12 to 11.3; p < 0.0001), but not for sacubitril/valsartan. In conclusion, study findings demonstrate a marked persistent treatment gap for HYD/NIT and similar poor utilization of sacubitril/valsartan in black patients with HFrEF despite current guideline recommendations.

The effects of adding angiotensin receptor neprilysin inhibitors to usual care in patients with heart failure: a protocol for a systematic review of randomised clinical trials with meta-analysis and trial sequential analysis

BACKGROUND

Heart failure is a highly prevalent disease with a global prevalence of 37 million, and the prevalence is increasing. Patients with heart failure are at an increased risk of death and morbidity. Traditionally, patients with heart failure have been treated with a beta-blocker in addition to an inhibitor of the renin-angiotensin-aldosterone system. However, new drugs are currently being added to the recommended guideline therapy. The latest drug to be added combines inhibition of the renin-angiotensin-aldosterone system pathway with inhibiting the neprilysin enzyme and is therefore classified as an ARNI. Our objective is to identify the beneficial and harmful effects of ARNIs in the treatment of patient with heart failure.

METHODS

This protocol for a systematic review was undertaken using the recommendations of the Cochrane, the Preferred Report Items of Systematic reviews with Meta-Analysis Protocols, and the eight-step assessment procedure suggested by Jakobsen and colleagues. We plan to include all relevant randomised clinical trials assessing the use of ARNIs in the treatment of patients with heart failure. We will search the Cochrane Central Register of Controlled Trials (CENTRAL), Medical Literature Analysis and Retrieval System Online (MEDLINE), Excerpta Medica database (EMBASE), Latin American and Caribbean Health Sciences Literature (LILACS), Science Citation Index Expanded on Web of Science, Chinese Biomedical Literature Database (CBM), China National Knowledge Infrastructure (CNKI), Chinese Science Journal Database (VIP), and BIOSIS to identify relevant trials. We will also search for grey literature and unpublished trials. Extracted data will be analysed using Review Manager 5, STATA 5, and Trial Sequential Analysis. Our primary outcomes will be all-cause mortality and serious adverse events. We will create a 'Summary of Findings' table in which we will present our primary and secondary outcomes, and we will assess the quality of evidence using the GRADE assessment.

DISCUSSION

The present systematic review will have the potential to aid clinicians in decision-making and thereby, benefit patients with heart failure.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019129336.

Hormone treatments in congestive heart failure

The common ultimate pathological feature for all cardiovascular diseases, congestive heart failure (CHF), is now considered as one of the main public health burdens that is associated with grave implications. Neurohormonal systems play a critical role in cardiovascular homeostasis, pathophysiology, and cardiovascular diseases. Hormone treatments such as the newly invented dual-acting drug valsartan/sacubitril are promising candidates for CHF, in addition to the conventional medications encompassing beta receptor blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and mineralocorticoid receptor antagonists. Clinical trials also indicate that in CHF patients with low insulin-like growth factor-1 or low thyroid hormone levels, supplemental treatment with growth hormone or thyroid hormone seems to be cardioprotective; and in CHF patients with volume overload the vasopressin antagonists can relieve the symptoms superior to loop diuretics. Furthermore, a combination of selective glucocorticoid receptor agonist and mineralocorticoid receptor antagonist may be used in patients with diuretic resistance. Finally, the potential cardiovascular efficacy and safety of incretin-based therapies, testosterone or estrogen supplementation needs to be prudently evaluated in large-scale clinical studies. In this review, we briefly discuss the therapeutic effects of several key hormones in CHF.

Pro-dopamine regulator, KB220Z, attenuates hoarding and shopping behavior in a female, diagnosed with SUD and ADHD

Background Addictive-like behaviors (e.g., hoarding and shopping) may be the result of the cumulative effects of dopaminergic and other neurotransmitter genetic variants as well as elevated stress levels. We, therefore, propose that dopamine homeostasis may be the preferred goal in combating such challenging and unwanted behaviors, when simple dopaminergic activation through potent agonists may not provide any resolution. Case presentation C.J. is a 38-year-old, single, female, living with her mother. She has a history of substance use disorder as well as attention deficit hyperactivity disorder, inattentive type. She had been stable on buprenorphine/naloxone combination and amphetamine, dextroamphetamine mixed salts for many years when unexpectedly she lost her job for oversleeping and not calling into work. KB200z (a pro-dopamine compound) was added to her regimen for complaints of low drive and motivation. After taking this nutraceutical for 4 weeks, she noticed a marked improvement in her mental status and many behaviors. She noted that her shopping and hoarding addictions had appreciably decreased. Furthermore, her lifelong history of terrifying lucid dreams was eliminated. Finally, she felt more in control; her locus of control shifted from external to more internal. Discussion The hypothesis is that C.J.'s reported, behavioral, and psychological benefits resulted from the pro-dopamine-regulating effect of KB220Z across the brain reward system. Conclusions This effect, we surmise, could be the result of a new dopamine balance, across C.J.'s brain reward system. Dopamine homeostasis is an effect of KB220Z seen in both animal and human placebo-controlled fMRI experiments.

[A Breakthrough in the Treatment of Patients With Heart Failure With Reduced Ejection Fraction: the Clinical Significance of the PARADIGM HF-Trial]

The implementation into clinical practice of new therapeutic strategies that could improve the prognosis of patients with heart failure (HF) with reduced ejection fraction (HFrEF) remains relevant. Innovative approach is to restore imbalances of neurohumoral systems by inhibiting angiotensin II receptor and neprilysin. The review presents the role of the natriuretic peptides system in the HFrEF pathophysiology, historical approaches to neurohormonal modulation, clinical pharmacology of the first in the class of angiotensin receptor and neprilysin inhibitor sakubitril/valsartan. The results of the study PARADIGM-HF, in which sakubitril/valsartan therapy in patients with HFrEF compared with the recommended doses of enalapril was associated with the decrease of the of cardiovascular death and hospitalizations for HF by 20%, the risk of death from any cause by 16%, improvement of symptoms and exercise tolerance. Sakubitril/valsartan tolerated better than enalapril, rarely causes a cough, hyperkalemia or renal dysfunction. There was no increase in the risk of angioedema. Based on the results of the study PARADIGM-HF sakubitril/valsartan was included in the national and international guidelines for HF.

Peripheral delivery of a CNS targeted, metalo-protease reduces aβ toxicity in a mouse model of Alzheimer's disease

Alzheimer's disease (AD), an incurable, progressive neurodegenerative disorder, is the most common form of dementia. Therapeutic options have been elusive due to the inability to deliver proteins across the blood-brain barrier (BBB). In order to improve the therapeutic potential for AD, we utilized a promising new approach for delivery of proteins across the BBB. We generated a lentivirus vector expressing the amyloid β-degrading enzyme, neprilysin, fused to the ApoB transport domain and delivered this by intra-peritoneal injection to amyloid protein precursor (APP) transgenic model of AD. Treated mice had reduced levels of Aβ, reduced plaques and increased synaptic density in the CNS. Furthermore, mice treated with the neprilysin targeting the CNS had a reversal of memory deficits. Thus, the addition of the ApoB transport domain to the secreted neprilysin generated a non-invasive therapeutic approach that may be a potential treatment in patients with AD.

Lentiviral vector neutral endopeptidase gene transfer suppresses prostate cancer tumor growth

Neprilysin (neutral endopeptidase, NEP) is a cell surface peptidase whose expression is lost in approximately 50% of prostate cancers (PC). NEP normally functions to inactivate peptides such as bombesin and endothelin-1, and potentiates the effects of the PTEN tumor suppressor via a direct protein-protein interaction. NEP loss contributes to PC progression. We investigated the therapeutic efficacy of using a lentiviral vector system to restore NEP expression in PC cells. Third-generation lentiviral vectors encoding wild-type NEP (L-NEP) or green fluorescent protein (L-GFP) were introduced into NEP-deficient 22RV1 PC cells. Cells infected with L-NEP or L-GFP at a multiplicity of infection of 10 demonstrated NEP enzyme activity of 1171.2+/-4.9 and 17.2+/-5.3 pmol/microg/min (P<0.0001), respectively. Cell viability, proliferation and invasion were each significantly inhibited in 22RV1 cells expressing NEP compared with control cells infected with L-GFP (P<0.01). Analysis of known downstream effects of NEP showed NEP-expressing cells exhibiting decreased Akt and focal adhesion kinase phosphorylation and increased PTEN protein expression. Finally, injection of L-NEP into established 22RV1 xenograft tumors significantly inhibited tumor growth (P<0.01). These experiments demonstrate that lentiviral NEP gene transfer is a novel targeted strategy for the treatment of NEP-deficient PC.

Targeting amyloid-degrading enzymes as therapeutic strategies in neurodegeneration

The levels of amyloid beta-peptides (Abeta) in the brain represent a dynamic equilibrium state as a result of their biosynthesis from the amyloid precursor protein (APP) by beta- and gamma-secretases, their degradation by a team of amyloid-degrading enzymes, their subsequent oligomerization, and deposition into senile plaques. While most therapeutic attention has focused on developing inhibitors of secretases to prevent Abeta formation, enhancing the rate of Abeta degradation represents an alternative and viable strategy. Current evidence both in vivo and in vitro suggests that there are three major players in amyloid turnover: neprilysin, endothelin converting enzyme(s), and insulin-degrading enzyme, all of which are zinc metallopeptidases. Other proteases have also been implicated in amyloid metabolism, including angiotensin-converting enzyme, and plasmin but for these the evidence is less compelling. Neprilysin and endothelin converting enzyme(s) are homologous membrane proteins of the M13 peptidase family, which normally play roles in the biosynthesis and/or metabolism of regulatory peptides. Insulin-degrading enzyme is structurally and mechanistically distinct. The regional, cellular, and subcellular localizations of these enzymes differ, providing an efficient and diverse mechanism for protecting the brain against the normal accumulation of toxic Abeta peptides. Reduction in expression levels of some of these proteases following insults (e.g., hypoxia and ischemia) or aging might predispose to the development of Alzheimer's disease. Conversely, enhancement of their levels by gene delivery or pharmacological means could be neuroprotective. Even a relatively small enhancement of Abeta metabolism could slow the inexorable progression of the disease. The relative merits of targeting these enzymes for the treatment of Alzheimer's disease will be reviewed and possible side-effects of enhancing their activity evaluated.

Dual angiotensin-converting enzyme/neutral endopeptidase inhibition on cardiac and renal fibrosis and inflammation in DOCA-salt hypertensive rats

OBJECTIVES

The relative roles of angiotensin-converting enzyme (ACE) and neutral endopeptidase (NEP) inhibition on cardiac and renal fibrosis in deoxycorticosterone acetate (DOCA)-salt hypertensive rats were studied.

METHODS

The ACE/NEP inhibitor omapatrilat (40 mg/kg per day), the ACE inhibitor enalapril (10 mg/kg per day) and the NEP inhibitor CGS 25462(100 mg/kg per day) were administrated for 3 weeks to DOCA rats. Collagen was stained with Sirius red, and mediators of inflammation were identified by immunolabeling (vascular cell adhesion molecule, nuclear factor-kappaB, infiltrating ED-1-positive macrophages and monocyte chemotactic protein-1) or by western blot (platelet-endothelial cell adhesion molecule-1).

RESULTS

Elevated systolic blood pressure of DOCA rats was significantly reduced (P < 0.05) by omapatrilat and CGS 25462. Omapatrilat and CGS 25462 significantly (P < 0.05) decreased interstitial collagen density in the left ventricle of DOCA rats compared with untreated DOCA rats. Enalapril only decreased the subepicardial collagen of DOCA rats. Omapatrilat significantly (P < 0.05) decreased renal mesangial collagen deposition in DOCA rats. Cardiac and renal expression of surface adhesion molecules, nuclear factor-kappaB, monocyte chemotactic protein and ED-1-positive cells were decreased in omapatrilat-treated DOCA rats compared with untreated DOCA rats. Enalapril and CGS 25462 did not alter mesangial collagen of DOCA rats.

CONCLUSIONS

Dual ACE/NEP inhibition was more effective than ACE or NEP inhibition in decreasing inflammatory mediators, and improving cardiac and renal fibrosis. This suggests a role for NEP inhibition added to blockade of the renin-angiotensin system that may explain the greater efficacy of omapatrilat.

[Vasopeptidases and their inhibitors]

The term vasopeptidase means any peptidase able to generate or to inactivate a vasoactive peptide. This term got a more definitive meaning when a new class of drugs, the vasopeptidase inhibitors, was introduced. These drugs are especially represented by the inhibitors of angiotensin-converting enzyme (ACE) and neutral endopeptidase (NEP). ACE is now primarily considered a kininase rather than an angiotensinase and ACE-inhibitors have been used successfully in the treatment of many cardiovascular diseases, including hypertension and heart failure. Preliminary results suggest that the use of NEP inhibitors could also contribute to improve prognosis of cardiovascular diseases. Vasopeptidase inhibitors simultaneously inhibiting both NEP and ACE have shown to be more effective than currently available ACE inhibitors. (Omapatrilat is at present the most clinically advanced in these drugs). However, many side-effects of vasopeptidase inhibitors have been reported, but the most dangerous is angioedema which is potentially life threatening. Since this complication is mediated by bradykinin, and both inhibition of ACE and NEP can produce bradykinin increasing, it has been suggested that the incidence of angioedema due to vasopeptidase inhibitors could be higher compared with that related to ACE-inhibitors. The FDA raised concern about this adverse effect, and the manufacturer decided to withdraw the application temporarily. In order to identify patients at risk of angioedema we have recently shown that low plasma levels of aminopeptidase P, another enzyme which cabolises bradykinin, could indicate a predisposition for development of angioedema in some patients treated with vasoinhibitor drugs.

Emerging concepts of neurohumoral modulation in the treatment of congestive heart failure

The angiotensin converting enzyme (ACE), endothelin (ET) converting enzyme (ECE) and neutral endopeptidase (NEP) are all zinc-metallopeptidases expressed in almost all the organs, such as heart, vessels and kidneys. While ACE and ECE are respectively involved in the transformation of angiotensin I and Big-ET into angiotensin II and ET-1 respectively, which possess vasoconstrictor and mitogenic properties, NEP is involved in the degradation of atrial natriuric factor (ANF), which possesses vasorelaxant, diuretic/natriuretic and antihypertrophic properties. These three systems are activated in heart failure and modulate the progression of heart failure. This article will discuss preliminary date concerning simultaneous inhibition of ACE, ECE and/or NEP and their therapeutic potential interest in the treatment of heart failure.

Novel targets for the control of secretory diarrhoea

Secretory diarrhoea continues to be a major clinical problem worldwide. It is now recognised that the enteric nervous system plays an important role in the pathogenesis of enterotoxin mediated intestinal secretion, which has resulted in the identification of novel therapeutic targets for the treatment of acute watery diarrhoea.

Effects of recombinant neutral endopeptidase (EC 3.4.24.11) on the growth of lung cancer cell lines in vitro and in vivo

Many lung cancers are stimulated by an autocrine/paracrine system of neuroendocrine peptide hormones. Attempts to block this autocrine growth pathway by interactions with specific ligand-receptor binding using monoclonal antibodies and peptide-specific antagonists have been largely unsuccessful because of the heterogeneity of hormone production and receptor expression. In the normal lung, neutral endopeptidase (NEP; CD10, CALLA, enkephalinase, and EC 3.4.24.11) plays a physiological role in degrading biologically active peptides, including all peptides implicated in autocrine growth stimulation of lung cancer. Cigarette smoke decreases the activity of NEP, indicating that the lack of NEP contributes to the dysregulation of the peptide autocrine system. The cloning of the human NEP gene allowed for production of sufficient quantities of recombinant NEP (rNEP) to evaluate its role in inhibiting the growth of lung cancer cells. In this study, we evaluated the ability of rNEP to inactivate the peptides involved in lung cancer signal transduction and to inhibit the growth of lung cancer cells as well as normal lung cells in vitro and in vivo in athymic nude mice. We showed that the growth inhibition of lung cancer cells by rNEP was related to the dose and schedule. Continuous exposure to high doses was required for growth inhibition. These studies confirm the importance of NEP in this autocrine pathway.

Recombinant neutral endopeptidase decreases oedema in the skin of burned guinea-pigs

Oedema, due to increased vascular leakage postburn, cases significant problems for burn patients. The purpose of this study was to determine if local application of a recombinant neutral endopeptidase (rNEP) would reduce the increased vascular permeability caused by a burn. In a guinea-pig model, a single treatment of rNEP given immediately postburn significantly decreased burn-induced plasma extravasation. This rNEP effect was dependent upon both the dosage of the peptidase and its enzymatic activity. Additional experiments were consistent with the rNEP acting partly by degrading bradykinin, a mediator of increased vascular permeability postburn. These findings suggest that further study of rNEP as a possible treatment for oedema is warranted.

[Treatment of acute chemically induced diarrhea by inhibition of enkephalinase. Results of a pilot study]

BACKGROUND AND OBJECTIVES

Acute chemotherapy-induced diarrhoea may require reducing or even stopping subsequent therapy. Antidiarrhoeal drug efficiency has not been extensively studied and the effects of the new antisecretory compound acetorphan--a potent enkephalinase inhibitor active in acute diarrhoea--are unknown. The aim of this study was to investigate the possible effects of acetorphan on 5 FU-induced diarrhoea in man.

MATERIAL AND METHODS

Fifteen patients reporting acute diarrhoea following chemotherapy were included in this study. They presented with metastatic colo-rectal cancer (n = 14) or pancreatic carcinoma (n = 1) and were treated, once weekly, by an 8-hour IV infusion of folinic acid 200 mg/m2 and 5 FU 1,800 to 3,000 mg/m2. In each patient, number and consistency of stools were assessed every day during the week following chemotherapy, once without (control period) and once with acetorphan p.o. 300 mg/d/7d.

RESULTS

During the control period, 3 out of 15 patients did not have significant diarrhoea, but 2 out of 3 patients had abdominal pain which was relieved by acetorphan without appearance of constipation. Twelve out of 15 patients presented with diarrhoea (> 3 stools/day for > 2 days: WHO grades 2 and 3); with acetorphan, the number of stools per day was reduced in all cases from 6.3 (range: 3-10.6) to 4.9 (range: 2.6-8.9) (P < 0.002), and the number of days with liquid stools dropped from 4.7 (range: 2-7) to 2.4 (range: 0-7) (P < 0.02). In addition, during treatment with acetorphan, there was a close positive linear relationship between the percent reduction in the number of stools and the number of stools during control period up to a 8 stools/day level (8 patients) above which efficiency decreased (4 patients).

CONCLUSION

These results suggest the efficacy of acetorphan on chemotherapy-induced diarrhoea and urgent need for a randomized controlled trial.