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Aims: Regulation of the renin-angiotensin system (RAS) in heart failure (HF) with reduced ejection fraction (HFrEF) still raises questions, as a large proportion of patients show normal renin levels despite manifest disease. Experimental venous congestion results in reduced renal perfusion pressure and stimulates renin secretion. We hypothesized that excess renin levels are mainly a result of right ventricular failure as a sequalae of left ventricular dysfunction. The study aimed to link right ventricular function (RVF) with renin levels and to investigate further contributors to excess RAS activation., Methods and Results: Three hundred thirty-two chronic HFrEF patients undergoing routine ambulatory care were consecutively enrolled in a prospective, registry-based, observational study. Laboratory parameters, including cardiac-specific markers renin, aldosterone, and N-terminal pro-brain natriuretic peptide (NT-proBNP), echocardiographic examination (n = 247), and right heart catheterization (n = 85), were documented. The relationship between renin and its respective parameters was analysed. Renin concentration was not associated with the New York Heart Association class or NT-proBNP. Systolic blood pressure, systemic vascular resistance, serum sodium, aldosterone, and lactate dehydrogenase were associated with increased renin levels (P < 0.035 for all). Renin levels similarly increased with worsening of RVF parameters such as fractional area change, tricuspid annular plane systolic excursion, tissue Doppler imaging, and inferior vena cava diameter (P < 0.011 for all), but not with pulmonary pressure. Excess renin levels were observed when worsening RVF was combined with reduced renal perfusion {625 μIU/mL [interquartile range (IQR): 182-1761] vs. 67 μIU/mL [IQR: 16-231], P < 0.001}, which was associated with worse survival., Conclusions: While unrelated to classical indices of HF severity, circulating renin levels increase with the worsening of RVF, especially in the combined presence of forward and backward failure. This might explain normal renin levels in HFrEF patients but also excess renin levels in poor haemodynamic conditions., (© 2024 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of European Society of Cardiology.)

Renin-angiotensin-aldosterone system (RAAS) inhibitors are standard care in patients with hypertension, heart failure or chronic kidney disease (CKD). Although we have studied the RAAS for decades, there are still circumstances that remain unclear. In this review, we describe the evolution of the RAAS and pose the question of whether this survival trait is still necessary to humankind in the present age. We elucidate the benefits on cardiovascular health and kidney disease of RAAS inhibition and present promising novel medications. Furthermore, we address why more studies are needed to establish a new standard of care away from generally prescribing ACEi or ARB toward an improved approach to combine drugs tailored to the needs of individual patients.

This study investigated whether sacubitril/valsartan or valsartan are able to prevent left ventricular (LV) fibrotic remodelling and dysfunction in two experimental models of pre-hypertension induced by continuous light (24 hours/day) exposure or by chronic lactacystin treatment, and how this potential protection interferes with the renin-angiotensin-aldosterone system (RAAS). Nine groups of three-month-old male Wistar rats were treated for six weeks as follows: untreated controls (C), sacubitril/valsartan (ARNI), valsartan (Val), continuous light (24), continuous light plus sacubitril/valsartan (24+ARNI) or valsartan (24+Val), lactacystin (Lact), lactacystin plus sacubitil/valsartan (Lact+ARNI) or plus valsartan (Lact+Val). Both the 24 and Lact groups developed a mild but significant systolic blood pressure (SBP) increase, LV hypertrophy and fibrosis, as well as LV systolic and diastolic dysfunction. Yet, no changes in serum renin-angiotensin were observed either in the 24 or Lact groups, though aldosterone was increased in the Lact group compared to the controls. In both models, sacubitril/valsartan and valsartan reduced elevated SBP, LV hypertrophy and fibrosis and attenuated LV systolic and diastolic dysfunction. Sacubitril/valsartan and valsartan increased the serum levels of angiotensin (Ang) II, Ang III, Ang IV, Ang 1-5, Ang 1-7 in the 24 and Lact groups and reduced aldosterone in the Lact group. We conclude that both continuous light exposure and lactacystin treatment induced normal-to-low serum renin-angiotensin models of pre-hypertension, whereas aldosterone was increased in lactacystin-induced pre-hypertension. The protection by ARNI or valsartan in the hypertensive heart in either model was related to the Ang II blockade and the protective Ang 1-7, while in lactacystin-induced pre-hypertension this protection seems to be additionally related to the reduced aldosterone level., Competing Interests: Declaration of Competing Interest The authors have no relevant financial or non-financial interests to disclose., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Guideline-directed medical therapy (GDMT) has improved outcomes in patients with heart failure, including the use of renin-angiotensin-aldosterone system inhibitors, which can hinder the excretion of potassium, resulting in hyperkalaemia. New potassium binders (NPBs) can prevent this adverse effect; however, the efficacy and safety of NPB for this indication have not been fully established. We conducted a systematic review and meta-analysis synthesizing randomized controlled trials (RCTs), which were retrieved by systematically searching PubMed, Web of Science, Scopus, and Cochrane through 26 April 2023. The risk of bias assessment was conducted, following Cochrane's updated Risk of Bias 2 assessment tool. We used the fixed-effects model to pool dichotomous data using risk ratio (RR) and continuous data using mean difference (MD), with a 95% confidence interval (CI) (PROSPERO ID: CRD42023426113). We included six RCTs with a total of 1432 patients. NPB was significantly associated with successful mineralocorticoid receptor antagonist (MRA) optimization [RR: 1.13 with 95% CI (1.02-1.25), P = 0.02], decreased patients with MRA at less than the target dose [RR: 0.72 with 95% CI (0.57-0.90), P = 0.004], and decreased hyperkalaemic episodes [RR: 0.42 with 95% CI (0.24-0.72), P = 0.002]. However, there was no difference between NPB and placebo regarding angiotensin-converting enzyme inhibitor (ACEi)/angiotensin receptor blocker (ARB)/angiotensin receptor/neprilysin inhibitor (ANRi) optimization [RR: 1.02 with 95% CI (0.89-1.17), P = 0.76] and serum potassium change [MD: -0.31 with 95% CI (-0.61 to 0.00), P = 0.05], with an acceptable safety profile except for the increased incidence of hypokalaemia with NPB [RR: 1.57 with 95% CI (1.12-2.21), P = 0.009]. NPB has been shown to improve GDMT outcomes by enhancing MRA optimization and reducing hyperkalaemic episodes. However, there are limited data on the effects of NPB on ACEi/ARB/ANRi optimization. Future RCTs should investigate ACEi/ARB/ANRi optimization and conduct head-to-head comparisons of NPB (patiromer and sodium zirconium cyclosilicate)., (© 2023 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of European Society of Cardiology.)

Epidemiological evidence of increased risks of cancer in heart failure (HF) patients and HF in cancer patients has suggested close relationships between the pathogenesis of both diseases. Indeed, HF and cancer share common risk factors, including aging and unhealthy lifestyles, and underlying mechanisms, including activation of the sympathetic nervous system and renin-angiotensin-aldosterone system, chronic inflammation, and clonal hematopoiesis of indeterminate potential. Mechanistically, HF accelerates cancer development and progression via secreted factors, so-called cardiokines, and epigenetic remodeling of bone marrow cells into an immunosuppressive phenotype. Reciprocally, cancer promotes HF via cachexia-related wasting and metabolic remodeling in the heart, and possibly via cancer-derived extracellular vesicles influencing myocardial structure and function. The novel concept of the "heart-cancer axis" will help in our understanding of the shared and reciprocal relationships between HF and cancer, and provide innovative diagnostic and therapeutic approaches for both diseases.

The advantage of angiotensin converting enzyme inhibitor (ACEI) and angiotensin receptor blocker (ARB) in patients with preserved LV systolic function is uncertain. We aimed to investigate the effects of ACEI/ARB in high atherosclerotic risk patients without overt heart failure (HF) on long-term major cardiovascular outcomes (MACEs). The Cohort Of patients with high Risk for cardiovascular Events (CORE-Thailand) registry is a prospective, multicenter, observational, longitudinal study of Thai patients with high atherosclerotic risk. The patients with ejection fraction < 50% were excluded. Among 8513 recruited patients, there were 4246 patients included into final analysis after propensity score matching. At 5-years follow-up, Cox regression analysis showed that ACEI/ARB was significantly associated with reduced risk of all-cause mortality or non-fatal myocardial infarction, non-fatal stroke and HF hospitalization (HR 0.82, 95% CI 0.70-0.96, P = 0.011). The benefit was driven by the reduced all-cause mortality and HF. Subgroup analysis demonstrated that ACEI/ARB decreased risk of long-term MACEs in patients with diabetes (HR 0.77, 95% CI 0.63-0.94, P = 0.011) and patients not taking statin (HR 0.57, 95% CI 0.40-0.82, P = 0.002). We demonstrated that the use of ACEI/ARB was associated with reduced risk of long-term MACEs in a large cohort of high atherosclerotic risk patients. Reduction of all-cause mortality and HF were likely the main contributors to the benefit of ACEI/ARB., (© 2023. The Author(s).)

Background: The renin-angiotensin system (RAS) activation is a proposed mechanism of muscle wasting (MW i.e., reduction in muscle mass). Although we reported that RAS inhibitors (RASIs) were associated with lower prevalence of MW in heart failure (HF) patients, the relationship between mineralocorticoid receptor (MR) signaling and MW has not been analyzed.Methods and Results: We analyzed data from 320 consecutive Japanese HF patients who underwent dual-energy X-ray absorptiometry scanning for assessment of appendicular skeletal muscle mass index (ASMI). In multiple linear regression analyses, plasma renin activity (PRA) was negatively correlated with ASMI in patients not receiving RASIs, indicating an untoward role of the RAS in MW. Results of analysis of covariance in which risk factors of MW served as covariates showed that use of MR antagonists (MRAs) was associated with lower ASMI and higher PRA in the non-RASIs group. The close relationship between use of MRAs and lower ASMI or higher PRA in the non-RASIs group was confirmed in analyses in which the differences in baseline characteristics between users and non-users of MRAs were minimized by using an inverse probability of treatment weighting., Conclusions: Increased PRA by MR inhibition without concurrent RAS inhibition, possibly contributing to upregulation of angiotensin II signaling, may be associated with reduction in muscle mass.

Background: Plasma renin activity (PRA) has gained relevance as prognostic marker in adults with heart failure. The use of PRA as a clinically meaningful parameter in children and children with heart failure requires a thorough knowledge of the factors that influence PRA to correctly assess PRA levels. We aim to evaluate the influence of age, heart failure and angiotensin-converting enzyme inhibitor (ACEi) on PRA levels in children., Methods: We conducted a systematic literature search to identify studies on PRA levels in healthy children and in children with heart failure. In addition, we analysed PRA data measured before (n = 35, aged 25 days-2.1 years), 4 hours after (n = 34) and within the first 8 days of enalapril treatment (n = 29) in children with heart failure from the European project Labeling of Enalapril from Neonates up to Adolescents (LENA)., Results: Age has a profound effect on PRA levels in healthy children, as PRA levels in the literature are up to about 7 times higher in neonates than in older children. Children with heart failure younger than 6 months showed 3-4 times higher PRA levels than healthy peers in both the literature and the LENA studies. In the LENA studies, the ACEi enalapril significantly increased median predose PRA by a factor of 4.5 in children with heart failure after 4.7 ± 1.6 days of treatment (n = 29, p < 0.01). Prior to treatment with enalapril, LENA subjects with symptomatic heart failure (Ross score ≥3) had a significantly higher PRA than LENA subjects with asymptomatic heart failure of comparable age (Ross score ≤2, p < 0.05)., Conclusions: Age, heart failure and ACEi treatment have a notable influence on PRA and must be considered when assessing PRA as a clinically meaningful parameter., Clinical Trial Registration: The trials are registered on the EU Clinical Trials Register (https://www.clinicaltrialsregister.eu)., Trial Registration Numbers: EudraCT 2015-002335-17, EudraCT 2015-002396-18., Competing Interests: The authors declare no conflict of interest., (© 2023 The Author(s). Published by IMR Press.)

Aims: Sex-specific differences in acute heart failure (AHF) are both relevant and underappreciated. Therefore, it is crucial to evaluate the risk/benefit ratio and the implementation of novel AHF therapies in women and men separately., Methods and Results: We performed a pre-defined sex-specific analysis in AHF patients randomized to a strategy of early intensive and sustained vasodilatation versus usual care in an international, multicentre, open-label, blinded endpoint trial. Inclusion criteria were AHF with increased plasma concentrations of natriuretic peptides, systolic blood pressure ≥100 mmHg, and plan for treatment in a general ward. Among 781 eligible patients, 288 (37%) were women. Women were older (median 83 vs. 76 years), had a lower body weight (median 64.5 vs. 77.6 kg) and lower estimated glomerular filtration rate (median 48 vs. 54 ml/min/1.73 m 2 ). The primary endpoint, a composite of all-cause mortality or rehospitalization for AHF at 180 days, showed a significant interaction of treatment strategy and sex (p for interaction = 0.03; hazard ratio adjusted for female sex 1.62, 95% confidence interval 1.05-2.50; p = 0.03). The combined endpoint occurred in 53 women (38%) in the intervention group and in 35 (24%) in the usual care group. The implementation of rapid up-titration of renin-angiotensin-aldosterone system (RAAS) inhibitors was less successful in women versus men in the overall cohort and in patients with heart failure with reduced ejection fraction (median discharge % target dose in patients randomized to intervention: 50% in women vs. 75% in men)., Conclusion: Rapid up-titration of RAAS inhibitors was less successfully implemented in women possibly explaining their higher rate of all-cause mortality and rehospitalization for AHF., Clinical Trial Registration: ClinicalTrials.gov, unique identifier NCT00512759., (© 2023 European Society of Cardiology.)

Background: Although doxorubicin (DOX) is a commonly used potent chemotherapeutic agent in patients with breast cancer, its cardiotoxic effect is a concern, particularly in patients with hypertension. Antihypertensive renin-angiotensin system (RAS) inhibitors may potentially play a role in preventing overt heart failure (HF) due to DOX toxicity. This study aimed to evaluate whether the use of RAS inhibitors improves clinical outcomes in patients with hypertension and breast cancer undergoing DOX-containing chemotherapy., Methods: A total of 54,344 female patients who were first diagnosed with breast cancer and initiated into DOX therapy between 2008 and 2015 were recruited from a nationwide Korean cohort. Patients were divided into two groups: with and without hypertension (HT, n = 10,789; non-HT, n = 43,555), and the RAS inhibitor group (n = 1,728) was sub-classified from the HT group. Two propensity score-matched cohorts were constructed to compare the clinical outcomes between non-HT and HT groups and between non-HT and RAS inhibitor groups. The primary outcome was the composite of HF and death., Results: After propensity score matching, the HT group had a higher risk for HF (adjusted hazard ratio [HR] = 1.30, 95% confidence intervals [95% CI] = 1.09-1.55) compared to the non-HT group, but there was no significant difference in primary outcome between the two groups. The RAS inhibitor group had a lower risk for primary outcome (adjusted HR = 0.78, 95% CI = 0.65-0.94) and death (adjusted HR = 0.81, 95% CI = 0.66-0.99) compared to the non-HT group., Conclusions: Hypertension is a risk factor for HF in patients with breast cancer undergoing DOX chemotherapy. However, the RAS inhibitors used to treat hypertension may contribute to decreased mortality and improved clinical outcomes., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Hwang, Lee. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

In patients with heart failure (HF), the neuroendocrine systems of the sympathetic nervous system (SNS), the renin-angiotensin-aldosterone system (RAAS) and the arginine vasopressin (AVP) system, are activated to various degrees producing often-observed tachycardia and concomitant increased systemic vascular resistance. Furthermore, sustained neurohormonal activation plays a key role in the progression of HF and may be responsible for the pathogenetic mechanisms leading to the perpetuation of the pathophysiology and worsening of the HF signs and symptoms. There are biomarkers of activation of these neurohormonal pathways, such as the natriuretic peptides, catecholamine levels and neprilysin and various newer ones, which may be employed to better understand the mechanisms of HF drugs and also aid in defining the subgroups of patients who might benefit from specific therapies, irrespective of the degree of left ventricular dysfunction. These therapies are directed against these neurohumoral systems (neurohumoral antagonists) and classically comprise beta blockers, angiotensin-converting enzyme (ACE) inhibitors/angiotensin receptor blockers and vaptans. Recently, the RAAS blockade has been refined by the introduction of the angiotensin receptor-neprilysin inhibitor (ARNI) sacubitril/valsartan, which combines the RAAS inhibition and neprilysin blocking, enhancing the actions of natriuretic peptides. All these issues relating to the neurohumoral activation in HF are herein reviewed, and the underlying mechanisms are pictorially illustrated.

Congestive heart failure (CHF) is often associated with impaired kidney function. Over- activation of the renin-angiotensin-aldosterone system (RAAS) contributes to avid salt/water retention and cardiac hypertrophy in CHF. While the deleterious effects of angiotensin II (Ang II) in CHF are well established, the biological actions of angiotensin 1-7 (Ang 1-7) are not fully characterized. In this study, we assessed the acute effects of Ang 1-7 (0.3, 3, 30 and 300 ng/kg/min, IV) on urinary flow (UF), urinary Na + excretion (UNaV), glomerular filtration rate (GFR) and renal plasma flow )RPF) in rats with CHF induced by the placement of aortocaval fistula. Additionally, the chronic effects of Ang 1-7 (24 µg/kg/h, via intra-peritoneally implanted osmotic minipumps) on kidney function, cardiac hypertrophy and neurohormonal status were studied. Acute infusion of either Ang 1-7 or its agonist, AVE 0991, into sham controls, but not CHF rats, increased UF, UNaV, GFR, RPF and urinary cGMP. In the chronic protocols, untreated CHF rats displayed lower cumulative UF and UNaV than their sham controls. Chronic administration of Ang 1-7 and AVE 0991 exerted significant diuretic, natriuretic and kaliuretic effects in CHF rats, but not in sham controls. Serum creatinine and aldosterone levels were significantly higher in vehicle-treated CHF rats as compared with controls. Treatment with Ang 1-7 and AVE 0991 reduced these parameters to comparable levels observed in sham controls. Notably, chronic administration of Ang 1-7 to CHF rats reduced cardiac hypertrophy. In conclusion, Ang 1-7 exerts beneficial renal and cardiac effects in rats with CHF. Thus, we postulate that ACE2/Ang 1-7 axis represents a compensatory response to over-activity of ACE/AngII/AT1R system characterizing CHF and suggest that Ang 1-7 may be a potential therapeutic agent in this disease state.

The role of taurine in the treatment of congestive heart failure (CHF) in dogs without systemic deficiency is unexplored. Taurine might have beneficial cardiac effects aside from deficit replacement. We hypothesized that oral taurine supplementation administered to dogs with naturally-occurring CHF would suppress the renin-angiotensin aldosterone system (RAAS). Oral taurine was administered to 14 dogs with stable CHF. Serum biochemical variables, blood taurine concentrations, and comprehensive analysis of RAAS variables were compared before and 2 weeks after taurine supplementation added to background furosemide and pimobendan therapy for CHF. Whole blood taurine concentrations increased after supplementation (median 408 nMol/mL, range 248-608 before and median 493 nMol/mL, range 396-690 after; P = .006). Aldosterone to angiotensin II ratio (AA2) was significantly decreased after taurine supplementation (median 1.00, range 0.03-7.05 before and median 0.65, range 0.01-3.63 after; P = .009), but no other RAAS components significantly differed between timepoints. A subset of dogs showed marked decreases in RAAS metabolites after supplementation and these dogs were more likely to have been recently hospitalized for CHF treatment than dogs that did not show marked decreases in classical RAAS metabolites. Overall, taurine only lowered AA2 in this group of dogs, however, response heterogeneity was noted, with some dogs showing RAAS suppression., (© 2023. The Author(s).)

Background: Activation of the reninangi otens in-aldosterone system has an important role in the pathophysiology of heart failure with reduced ejection fraction. While the effects of systemic reninangi otens in-aldosterone system activation on heart failure with reduced ejection fraction are well known, the impact of the local reninangi otens in-aldosterone system on heart failure with reduced ejection fraction is not fully understood because of limited clinical research. This study aimed to investigate the effect of urinary angiotensinogen level, an accepted indicator of local reninangi otens in-aldosterone system activation, on all-cause mortality in patients with heart failure with reduced ejection fraction., Methods: This retrospective, single-center study included 60 patients with baseline urinary angiotensinogen data and survival/mortality data at 4 years. Urinary angiotensinogen values were standardized to the urinary creatinine value measured from the same urine sample. The median urinary angio tensi nogen /urin ary creatinine value among all patients (114 μg/g) was used as a cutoff to divide the patients into 2 groups. Mortality data were obtained from the national registry systems or by telephone., Results: Comparison of all-cause mortality in the 2 groups showed that 22 deaths (71%) occurred in the group with a urinary angio tensinogen/urinary creatinine ratio above the median and 10 deaths (35.5%) occurred in the group of patients with urinary angio tensinogen/urinary creatinine equal to or below the median value (P =.005)., Conclusion: Our study suggests that urinary angiotensinogen can be used as a new biomarker in the prognosis and follow-up of heart failure patients.

Aims: Large outcome studies demonstrated a reduction of heart failure hospitalization or cardiovascular death in patients with chronic heart failure (CHF). The renin-angiotensin system (RAS) is a key player in fluid and sodium regulation. The classic angiotensin-converting enzyme-angiotensin II-angiotensin-1 receptor axis (Ang I-ACE-Ang II receptor axis) is predominantly angiotensin II (Ang-II) induced and promotes vasoconstriction. In contrast, the angiotensin-converting-enzyme-2-angiotensin-(1-7)-Mas axis (Mas-axis) is mediated by the metabolites angiotensin-1-7 (Ang-(1-7)) and angtiotensin-1-5 (Ang-(1-5)) and exerts cardioprotective effects., Methods: We previously investigated the effect of empagliflozin on the systemic haemodynamic in patients with stable CHF (NYHA II-III) in a randomized placebo-controlled clinical trial 'Analysing the Effect of Empagliflozin on Reduction of Tissue Sodium Content in Patients With Chronic Heart Failure (ELSI)'. In a post hoc analysis, we now analysed whether empagliflozin has an effect on the RAS by measuring detailed RAS profiles (LC-MS/MS-based approach) in 72 patients from ELSI. We compared RAS parameters after 1-month and 3-months treatment with empagliflozin or placebo to baseline. The secondary goal was to analyse whether the effect of empagliflozin on RAS parameters was dependent on angiotensin-receptor-blocking (ARB) or angiotensin-converting-enzyme-inhibitor (ACEI) co-medication., Results: Empagliflozin medication induced a significant rise in Ang-II [68.5 pmol/L (21.3-324.2) vs. 131.5 pmol/L (34.9-564.0), P = 0.001], angiotensin-I (Ang-I) [78.7 pmol/L (21.5-236.6) vs. 125.9 pmol/L (52.6-512.9), P < 0.001], Ang-(1-7) [3.0 pmol/L (3.0-15.0) vs. 10.1 pmol/L (3.0-31.3), P = 0.006], and Ang-(1-5) [5.4 pmol/L (2.0-22.9) vs. 9.9 pmol/L (2.8-36.4), P = 0.004], which was not observed in the placebo group (baseline to 3-months treatment). A significant rise in Ang-II (206.4 pmol/L (64.2-750.6) vs. 568.2 pmol/L (164.7-1616.4), P = 0.001), Ang-(1-7) (3.0 pmol/L (3.0-14.1) vs. 15.0 pmol/L (3.0-31.3), P = 0.017), and Ang-(1-5) [12.2 pmol/L (3.8-46.6) vs. 36.4 pmol/L (11.1-90.7), P = 0.001] under empagliflozin treatment was only seen in the subgroup of patients with ARB co-medication, whereas no change of Ang-II (16.7 pmol/L (2.0-60.8) vs. 26.4 pmol/L (10.7-63.4), P = 0.469), Ang-(1-7) (6.6 pmol/L (3.0-20.7) vs. 10.5 pmol/L (3.0-50.5), P = 0.221), and Ang-(1-5) (2.7 pmol/L (2.0-8.4) vs. 2.8 pmol/L (2.0-6.9), P = 0.851) was observed in patients with empagliflozin that were on ACEI co-medication (baseline to 3-months treatment)., Conclusions: Our data indicate that empagliflozin might lead to an activation of both the Ang I-ACE-Ang II receptor axis and the Mas-axis pathway. Activation of the Ang I-ACE-Ang II receptor axis and the protective Mas-axis pathway after initiating treatment with empagliflozin was only seen in patients with ARB co-medication, in contrast to co-medication with ACEI., (© 2023 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of European Society of Cardiology.)

Renin-angiotensin-aldosterone system inhibitors (RAASi) and mineralocorticoid receptor antagonists (MRAs) are important interventions to improve outcomes in patients with chronic kidney disease and heart failure, but their use is limited in some patients by the development of hyperkalemia. The risk of hyperkalemia may differ between agents, with one trial showing lower risk of hyperkalemia with the novel non-steroidal MRA finerenone compared with steroidal MRA spironolactone. Novel potassium binders, including patiromer and sodium zirconium cyclosilicate, are available interventions to manage hyperkalemia and enable continuation of RAASi and MRAs in patients who could benefit from these treatments. These agents bind free potassium ions in the lumen of the gastrointestinal tract to prevent the absorption of dietary potassium and increase potassium secretion. Several studies showed that potassium binders are effective compared with placebo for preventing hyperkalemia or steroidal MRA discontinuation, but none has evaluated whether this strategy impacts clinically important endpoints such as cardiovascular events. Due to this and other limitations related to cost, clinical availability, pill burden and patient selection, alternative potential strategies to mitigate hyperkalemia may be more practical. Conservative strategies include increased monitoring and use of loop or thiazide diuretics to increase urinary potassium excretion. Non-steroidal MRAs may have a lower risk of hyperkalemia than steroidal MRAs and have stronger anti-inflammatory and anti-fibrotic effects with resultant reduced risk of kidney disease progression. Sodium-glucose cotransporter-2 inhibitors also decrease hyperkalemia risk in patients on MRAs and decrease cardiovascular events and kidney disease progression. These may be better first-line interventions to obviate the need for potassium binders and offer additional benefits., (© The Author(s) 2022. Published by Oxford University Press on behalf of the ERA.)

Background: The evidence supporting the use of renin-angiotensin-aldosterone system (RAAS) inhibitors and beta-blockers for the prevention of anthracycline-induced cardiomyopathy is controversial., Objective: We performed a meta-analysis to assess the effectiveness of these drugs in preventing cardiotoxicity., Methods: The meta-analysis included prospective, randomized studies in adults receiving anthracycline chemotherapy and compared the use of RAAS inhibitors or beta-blockers versus placebo with a follow-up of 6 to 18 months. The primary outcome was change in left ventricular ejection fraction (LVEF) during chemotherapy. Secondary outcomes were the incidence of heart failure, all-cause mortality, and changes in end-diastolic measurement. Heterogeneity was assessed by stratification and meta-regression. A significance level of p < 0.05 was adopted., Results: The search resulted in 17 studies, totaling 1,530 patients. The variation (delta) in LVEF was evaluated in 14 studies. Neurohormonal therapy was associated with a lower delta in pre- versus post-therapy LVEF (weighted mean difference 4.42 [95% confidence interval 2.3 to 6.6]) and higher final LVEF (p < 0.001). Treatment resulted in a lower incidence of heart failure (risk ratio 0.45 [95% confidence interval 0.3 to 0.7]). There was no effect on mortality (p = 0.3). For analysis of LVEF, substantial heterogeneity was documented, which was not explained by the variables explored in the study., Conclusion: The use of RAAS inhibitors and beta-blockers to prevent anthracycline-induced cardiotoxicity was associated with less pronounced reduction in LVEF, higher final LVEF, and lower incidence of heart failure. No changes in mortality were observed. (CRD PROSPERO 42019133615).

Background: Chronic kidney disease (CKD) patients with and without heart failure (HF) often present with hyperkalaemia (HK) leading to increased risk of hospitalisations, cardiovascular related events and cardiovascular-related mortality. Renin-angiotensin-aldosterone system inhibitor (RAASi) therapy, the mainstay treatment in CKD management, provides significant cardiovascular and renal protection. Nevertheless, its use in the clinic is often suboptimal and treatment is frequently discontinued due to its association with HK. We evaluated the cost-effectiveness of patiromer, a treatment known to reduce potassium levels and increase cardiorenal protection in patients receiving RAASi, in the UK healthcare setting., Methods: A Markov cohort model was generated to assess the pharmacoeconomic impact of patiromer treatment in regulating HK in patients with advanced CKD with and without HF. The model was generated to predict the natural history of both CKD and HF and quantify the costs and clinical benefits associated with the use of patiromer for HK management from a healthcare payer's perspective in the UK., Results: Economic evaluation of patiromer use compared to standard of care (SoC) resulted in increased discounted life years (8.93 versus 8.67) and increased discounted quality-adjusted life years (QALYs) (6.36 versus 6.16). Furthermore, patiromer use resulted in incremental discounted cost of £2,973 per patient and an incremental cost-effectiveness ratio (ICER) of £14,816 per QALY gained. On average, patients remained on patiromer therapy for 7.7 months, and treatment associated with a decrease in overall clinical event incidence and delayed CKD progression. Compared to SoC, patiromer use resulted in 218 fewer HK events per 1,000 patients, when evaluating potassium levels at the 5.5-6 mmol/l; 165 fewer RAASi discontinuation episodes; and 64 fewer RAASi down-titration episodes. In the UK, patiromer treatment was predicted to have a 94.5% and 100% chance of cost-effectiveness at willingness-to-pay thresholds (WTP) of £20,000/QALY and £30,000/QALY, respectively., Conclusion: This study highlights the value of both HK normalisation and RAASi maintenance in CKD patients with and without HF. Results support the guidelines which recommend HK treatment, e.g., patiromer, as a strategy to enable the continuation of RAASi therapy and improve clinical outcomes in CKD patients with and without HF., (© 2023. The Author(s).)

Prognostic effect of discontinuing renin-angiotensin-aldosterone-system-inhibitor (RAASi) for patients with heart failure (HF) after acute myocardial infarction (AMI) whose left ventricular (LV) systolic function was restored during follow-up is unknown. To investigate the outcome after discontinuing RAASi in post-AMI HF patients with restored LV ejection fraction (EF). Of 13,104 consecutive patients from the nationwide, multicenter, and prospective Korea Acute Myocardial Infarction-National Institutes of Health (KAMIR-NIH) registry, HF patients with baseline LVEF < 50% that was restored to ≥ 50% at 12-month follow-up were selected. Primary outcome was a composite of all-cause death, spontaneous MI, or rehospitalization for HF at 36-month after index procedure. Of 726 post-AMI HF patients with restored LVEF, 544 maintained RAASi (Maintain-RAASi) beyond 12-month, 108 stopped RAASi (Stop-RAASi), and 74 did not use RAASi (RAASi-Not-Used) at baseline and follow-up. Systemic hemodynamics and cardiac workloads were similar among groups at baseline and during follow-up. Stop-RAASi group showed elevated NT-proBNP than Maintain-RAASi group at 36-month. Stop-RAASi group showed significantly higher risk of primary outcome than Maintain-RAASi group (11.4% vs. 5.4%; adjusted hazard ratio [HR adjust ] 2.20, 95% confidence interval [CI] 1.09-4.46, P = 0.028), mainly driven by increased risk of all-cause death. The rate of primary outcome was similar between Stop-RAASi and RAASi-Not-Used group (11.4% vs. 12.1%; HR adjust 1.18 [0.47-2.99], P = 0.725). In post-AMI HF patients with restored LV systolic function, RAASi discontinuation was associated with significantly increased risk of all-cause death, MI, or rehospitalization for HF. Maintaining RAASi will be necessary for post-AMI HF patients, even after LVEF is restored., (© 2023. The Author(s).)

The renin-angiotensin-aldosterone-systems (RAAS) play a central role in the pathophysiology of congestive heart failure (CHF), justifying the use of angiotensin converting enzyme inhibitors (ACEi) in dogs and humans with cardiac diseases. Seminal studies in canine CHF had suggested that the pharmacological action of benazepril was relatively independent of doses greater than 0.25 mg/kg P.O, thereby providing a rationale for the European labeled dose of benazepril in dogs with CHF. However, most of these earlier studies relied on measures of ACE activity, a sub-optimal endpoint to characterize the effect of ACEi on the RAAS. The objectives of this study were (i) to expand on previous mathematical modeling efforts of the dose-exposure-response relationship of benazepril on biomarkers of the RAAS which are relevant to CHF pathophysiology and disease prognosis; and (ii) to develop a software implementation capable of simulating clinical trials in benazepril in dogs bedside dose optimization. Our results suggest that 0.5 mg/kg PO q12h of benazepril produces the most robust reduction in angiotensin II and upregulation of RAAS alternative pathway biomarkers. This model will eventually be expanded to include relevant clinical endpoints, which will be evaluated in an upcoming prospective trial in canine patients with CHF., (© 2023. The Author(s).)

Background: Association of congestive heart failure (CHF) and chronic kidney disease (CKD) worsens the patient's prognosis and results in poor survival rate. The aim of this study was to examine if addition of endothelin type A (ET A ) receptor antagonist to the angiotensin-converting enzyme inhibitor (ACEi) will bring additional beneficial effects in experimental rats., Methods: CKD was induced by 5/6 renal mass reduction (5/6 NX) and CHF was elicited by volume overload achieved by creation of aorto-caval fistula (ACF). The follow-up was 24 weeks after the first intervention (5/6 NX). The treatment regimens were initiated 6 weeks after 5/6 NX and 2 weeks after ACF creation., Results: The final survival in untreated group was 15%. The treatment with ET A receptor antagonist alone or ACEi alone and the combined treatment improved the survival rate to 64%, 71% and 75%, respectively, however, the difference between the combination and either single treatment regimen was not significant. The combined treatment exerted best renoprotection, causing additional reduction in albuminuria and reducing renal glomerular and tubulointerstitial injury as compared with ACE inhibition alone., Conclusions: Our results show that treatment with ET A receptor antagonist attenuates the CKD- and CHF-related mortality, and addition of ET A receptor antagonist to the standard blockade of RAS by ACEi exhibits additional renoprotective actions., Competing Interests: Declaration of Competing Interest The authors of this manuscript have nothing to declare., (Copyright © 2022 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Background: Hyperkalemia (HK) is a barrier to optimization of renin-angiotensin-aldosterone system inhibitor (RAASi) therapy in heart failure (HF) and chronic kidney disease (CKD). We investigated cardiorenal risk associated with changes in RAASi regimen after an episode of HK in patients with HF and/or CKD., Methods: This observational study utilized data from hospital records, claims, and health registers from the US (Optum's de-identified Market Clarity Data) and Japan (Medical Data Vision). Included patients had an index episode of HK between July 2019 and September 2021 (US), or May 2020 and September 2021 (Japan), with prior diagnosis of HF or CKD (stage 3 or 4), and RAASi use. Risk of a cardiorenal composite outcome (HF emergency visit, HF hospitalization, or progression to end-stage kidney disease) was determined in patients who discontinued RAASi, down-titrated their dose by > 25%, or maintained or up-titrated their dose following the HK episode., Results: A total of 15,488 and 6020 patients were included from the US and Japan, respectively. Prior to the episode of HK, 59% (US) and 27% (Japan) of patients had achieved > 50% target RAASi dose. Following the episode of HK, 33% (US) and 32% (Japan) of patients did not fill a new RAASi prescription. Risk of the cardiorenal outcome at 6 months was higher in patients who discontinued or down-titrated versus maintained or up-titrated RAASi treatment both in the US (17.5, 18.3, and 10.6%; p <  0.001) and in Japan (19.7, 20.0, and 15.1%; p <  0.001)., Conclusion: HK-related RAASi discontinuation or down-titration was associated with higher risk of cardiorenal events versus maintained or up-titrated RAASi., (© 2023. The Author(s).)

Heart failure (HF) and atrial fibrillation (AF) are two cardiovascular (CV) entities that affect millions of individuals worldwide and their prevalence is translated into a significant impact on health care systems. The common pathophysiological pathways that these two share have created an important clinical interrelation, as the coexistence of HF and AF is associated with worse prognosis and treatment challenges. Renin-angiotensin-aldosterone system (RAAS), a critical mechanism in blood pressure (BP) control, was proved to be involved in the pathogenesis of both conditions contributing to their further coexistence. Successful control of BP is of great importance to the management of HF, crucial for the prevention of arrhythmiogenic substrates, while RAAS antagonists may possibly affect the development of new-onset AF as well. There are numerous studies that evaluated the effectiveness of RAAS blockade in AF/HF population and despite comparable or modest results, there is a well-established suggestion that RAAS blockers may contribute to a reduction of HF, CV events and recurrence of AF, along with their potential effective role in the new-onset AF prophylaxis. Angiotensin receptor blockers, according to the evidence, are more effective in that direction, followed by angiotensin converting enzyme inhibitors, whereas the data on aldosterone antagonists are not encouraging, yet do have the potential of significant CV disease modificators regardless of their effects on BP.

Aging is an important risk factor for the development of heart failure (HF) and half of patients with HF have preserved ejection fraction (HFpEF) which is more common in elderly women. In general, sex differences that lead to discrepancies in risk factors and to the development of cardiovascular disease (CVD) have been attributed to the reduced level of circulating estrogen during menopause. Estrogen receptors adaptively modulate fibrotic, apoptotic, inflammatory processes and calcium homeostasis, factors that are directly involved in the HFpEF. Therefore, during menopause, estrogen depletion reduces the cardioprotection. Preclinical menopause models demonstrated that several signaling pathways and organ systems are closely involved in the development of HFpEF, including dysregulation of the renin-angiotensin system (RAS), chronic inflammatory process and alteration in the sympathetic nervous system. Thus, this review explores thealterations observed in the condition of HFpEF induced by menopause and the therapeutic targets with potential to interfere with the disease progress.

Hyperkalemia is associated with increased risks of mortality and adverse clinical outcomes. The treatment of hyperkalemia often leads to the discontinuation or restriction of beneficial but potassium-increasing therapy such as renin-angiotensin-aldosterone inhibitors (RAASi) and high-potassium diet including fruits and vegetables. To date, limited evidence is available for personalized risk evaluation in this heterogeneous and multifactorial pathophysiological condition. We developed risk prediction models using extreme gradient boosting (XGB), multiple logistic regression (LR), and deep neural network. Models were derived from a retrospective cohort of hyperkalemic patients with either heart failure or chronic kidney disease stage ≥3a from a Japanese nationwide database (1 April 2008−30 September 2018). Studied outcomes included all-cause death, renal replacement therapy introduction (RRT), hospitalization for heart failure (HHF), and cardiovascular events within three years after hyperkalemic episodes. The best performing model was further validated using an external cohort. A total of 24,949 adult hyperkalemic patients were selected for model derivation and internal validation. A total of 1452 deaths (16.6%), 887 RRT (10.1%), 1,345 HHF (15.4%), and 621 cardiovascular events (7.1%) were observed. XGB outperformed other models. The area under receiver operator characteristic curves (AUROCs) of XGB vs. LR (95% CIs) for death, RRT, HHF, and cardiovascular events were 0.823 (0.805−0.841) vs. 0.809 (0.791−0.828), 0.957 (0.947−0.967) vs. 0.947 (0.936−0.959), 0.863 (0.846−0.880) vs. 0.838 (0.820−0.856), and 0.809 (0.784−0.834) vs. 0.798 (0.772−0.823), respectively. In the external dataset including 86,279 patients, AUROCs (95% CIs) for XGB were: death, 0.747 (0.742−0.753); RRT, 0.888 (0.882−0.894); HHF, 0.673 (0.666−0.679); and cardiovascular events, 0.585 (0.578−0.591). Kaplan−Meier curves of the high-risk predicted group showed a statistically significant difference from that of the low-risk predicted groups for all outcomes (p < 0.005; log-rank test). These findings suggest possible use of machine learning models for real-world risk assessment as a guide for observation and/or treatment decision making that may potentially lead to improved outcomes in hyperkalemic patients while retaining the benefit of life-saving therapies.

Aims: To investigate the impact of patiromer on the serum potassium level and its ability to enable specified target doses of renin-angiotensin-aldosterone system inhibitor (RAASi) use in patients with heart failure and reduced ejection fraction (HFrEF)., Methods and Results: A total of 1642 patients with HFrEF and current or a history of RAASi-related hyperkalemia were screened and 1195 were enrolled in the run-in phase with patiromer and optimization of the RAASi therapy [≥50% recommended dose of angiotensin-converting enzyme inhibitor/angiotensin receptor blocker/angiotensin receptor-neprilysin inhibitor, and 50 mg of mineralocorticoid receptor antagonist (MRA) spironolactone or eplerenone]. Specified target doses of the RAASi therapy were achieved in 878 (84.6%) patients; 439 were randomized to patiromer and 439 to placebo. All patients, physicians, and outcome assessors were blinded to treatment assignment. The primary endpoint was between-group difference in the adjusted mean change in serum potassium. Five hierarchical secondary endpoints were assessed. At the end of treatment, the median (interquartile range) duration of follow-up was 27 (13-43) weeks, the adjusted mean change in potassium was +0.03 mmol/l in the patiromer group and +0.13 mmol/l in the placebo group [difference in the adjusted mean change between patiromer and placebo: -0.10 mmol/l (95% confidence interval, CI -0.13, 0.07); P < 0.001]. Risk of hyperkalemia >5.5 mmol/l [hazard ratio (HR) 0.63; 95% CI 0.45, 0.87; P = 0.006), reduction of MRA dose (HR 0.62; 95% CI 0.45, 0.87; P = 0.006), and total adjusted hyperkalemia events/100 person-years (77.7 vs. 118.2; HR 0.66; 95% CI 0.53, 0.81; P < 0.001) were lower with patiromer. Hyperkalemia-related morbidity-adjusted events (win ratio 1.53, P < 0.001) and total RAASi use score (win ratio 1.25, P = 0.048) favored the patiromer arm. Adverse events were similar between groups., Conclusion: Concurrent use of patiromer and high-dose MRAs reduces the risk of recurrent hyperkalemia (ClinicalTrials.gov: NCT03888066)., Competing Interests: Conflict of interest: All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. T.F. reported consulting fees from Vifor Pharma, Bayer, Biosense Webster, CSL Behring, Galapagos, Minoryx, Novartis, LivaNova, Janssen, Roche, and honoraria from Fresenius Kabi. J.B. reported consulting fees from Abbott, Adrenomed, Amgen, Applied Therapeutics, Array, AstraZeneca, Bayer, Boehringer Ingelheim, CVRx, G3 Pharma, Impulse Dynamics, Innolife, Janssen, LivaNova, Luitpold, Medtronic, Merck, Novartis, Novo Nordisk, Relypsa, Sequana Medical, and Vifor Pharma. G.F. reported honoraria from Bayer and Boehringer Ingelheim, committee membership for Medtronic, Vifor Pharma, Amgen, Servier, and Novartis, and grants from the European Commission. M.R.W. reported consulting fees from Vifor Pharma and AstraZeneca, and honoraria from Vifor Pharma. P.V.d.M. reported grants from Vifor Pharma, Pfizer, AstraZeneca, and Ionis, consulting fees from Vifor Pharma, Novartis and AstraZeneca, and honoraria from Vifor Pharma and Pharmacosmos. L.H.L. reported grants from AstraZeneca, Vifor, Boston Scientific, Boehringer Ingelheim, and Novartis, consulting fees from Merck, Vifor Pharma, AstraZeneca, Bayer, Pharmacosmos, MedScape, Sanofi, Lexicon, Myokardia, Boehringer Ingelheim, and Servier, honoraria from Abbott, MedScape, Radcliffe, AstraZeneca, and Novartis, and stock options and patents with AnaCardio. F.D. reported support and stock options from Vifor Pharma as a Vifor employee. F.P. reported consulting fees from Vifor Pharma and Novo Nordisk, honoraria from Servier, Pfizer, Novartis, and Boehringer Ingelheim, and presidency (unpaid) of the World Heart Federation. S.D.A. reports consulting fees from Abbott, Bayer, Boehringer Ingelheim, Cardiac Dimension, Cordio, Impulse Dynamics, Novartis, Occlutech, Servier, and Vifor Pharma, and grant support from Abbott and Vifor Pharma. M.M. reported consulting fees from Actelion, Amgen, AstraZeneca, Abbott Vascular, Bayer, Servier, Edwards Therapeutics, Livanova, Vifor Pharma, and WindTree Therapeutics. UMG reports grants, support and stock options from Vifor Pharma. M.K. reported consulting fees from Amgen, Applied Therapeutics, AstraZeneca, Bayer, Boehringer Ingelheim, Eli Lilly, Esperion Therapeutics, Janssen, Merck, Novo Nordisk, Sanofi, and Vifor Pharma, grants from AstraZeneca and Boehringer Ingelheim, and grant support from Abbott and Vifor Pharma, and honoraria from AstraZeneca, Boehringer Ingelheim, and Novo Nordisk. A.C. reported honoraria from AstraZeneca, Bayer, Boehringer Ingelheim, Menarini, Novartis, Nutricia, Servier, Vifor, Abbott, Actimed, Arena, Cardiac Dimensions, Corvia, CVRx, Enopace, ESN Cleer, Faraday, Gore, Impulse Dynamics, Respicardia, and Viatris. P.R. reported grants from AstraZeneca, Bayer, Fresenius, Novartis, Vifor Fresenius Medical Care Renal Pharma, Relypsa, and Vifor, consulting fees from Bayer, Idorsia, G3P, KBP, and Sanofi, honoraria from Sequana medical, AstraZeneca, Bayer, Fresenius, Novartis, Grünenthal, Stealth Peptides, Vifor Fresenius Medical Care Renal, Novo Nordisk, Ablative Solutions, Corvidia, Relypsa, and Vifor CardioRenal, and non-financial support from Servier, Fresenius, and G3P. I.L.P. serves on an advisory board for Vifor Pharma Ltd and on the Steering Committee of the DIAMOND clinical trial. B.P. reported consulting fees from AstraZeneca, Boehringer Ingelheim/Lilly, Sanofi/Lexicon, SCPharmaceuticals, SQinnovations, G3 Pharmaceuticals, Sarfez, KBP biosciences, Cereno scientific, Phase bio, Proton Intel, and Vifor Pharma, stock options from SCPharmaceuticals, SQinnovations, G3 Pharmaceuticals, Sarfez, Cereno scientific, KBP biosciences, Proton Intel, and Vifor Pharma, US Patent 9931412- site specific delivery of eplerenone to the myocardium, and US Patent pending 63/045,783—Histone-modulating agents for the treatment and prevention of organ damage. No other authors reported disclosures., (© The Author(s) 2022. Published by Oxford University Press on behalf of European Society of Cardiology.)

In the era of the initial optimal interventional and medical therapy for acute myocardial infarction (AMI), a number of patients with mildly reduced left ventricular ejection fraction (EF) (41%-49%) have been increasing. This observational study aimed to investigate the association between the medical therapy with oral beta-blockers or inhibitors of renin-angiotensin system (RAS) and 2-year clinical outcomes in patients with mildly reduced EF after AMI. Among patients enrolled in the Korea Acute Myocardial Infarction Registry-National Institute of Health, propensity-score matched patients who survived the initial attack and had mildly reduced EF were selected according to beta-blocker or RAS inhibitor therapy at discharge. Beta-blocker therapy at discharge was associated with lower 2-year major adverse cardiac events which was a composite of cardiac death, myocardial infarction, revascularization and re-hospitalization due to heart failure (8.7 vs 12.8/100 patient-years; hazard ratio [HR] 0.68; 95% confidence interval [CI] 0.50-0.93; P = .015), and no significant interaction between EF ≤ 45% and > 45% was observed (Pinteraction = 0.354). This association was mainly driven by lower myocardial infarction in patients with beta-blockers (HR 0.50; 95% CI 0.26-0.95; P = .035). Inhibitors of RAS at discharge were associated with lower re-hospitalization due to heart failure (1.8 vs 3.5/100 patient-years; HR 0.53; 95% CI 0.33-0.86; P = .010) without a significant interaction between EF ≤ 45% and > 45% (Pinteraction = 0.333). In patients with mildly reduced EF after AMI, the medical therapy with beta-blockers or RAS inhibitors at discharge was associated with better 2-year clinical outcomes., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2022 the Author(s). Published by Wolters Kluwer Health, Inc.)

The renin-angiotensin-aldosterone system (RAAS) is a well-defined pathway playing a key role in maintaining circulatory homeostasis. Abnormal activation of RAAS contributes to development of cardiovascular disease, including heart failure, cardiac hypertrophy, hypertension, and atherosclerosis. Although several key RAAS enzymes and peptide hormones have been thoroughly investigated, the role of angiotensinogen-the precursor substrate of the RAAS pathway-remains less understood. The study of angiotensinogen single-nucleotide polymorphisms (SNPs) has provided insight into associations between angiotensinogen and hypertension, congestive heart failure, and atherosclerotic cardiovascular disease. Targeted drug therapy of RAAS has dramatically improved clinical outcomes for patients with heart failure, myocardial infarction, and hypertension. However, all such therapeutics block RAAS components downstream of angiotensinogen and elicit compensatory pathways that limit their therapeutic efficacy as monotherapy. Upstream RAAS targeting by an angiotensinogen inhibitor has the potential to be more efficacious in patients with suboptimal RAAS inhibition and has a better safety profile than multiagent RAAS blockade. Newly developed therapeutics that target angiotensinogen through antisense oligonucleotides or silencer RNA technologies are providing a novel perspective into the pathobiology of angiotensinogen and show promise as the next frontier in the treatment of cardiovascular disease., Competing Interests: Funding Support and Author Disclosures The authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2022 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Aims: Hospitalization for heart failure treatment (HHF) is an incisive event in the course of HF. Today, the large majority of HHF patients is ≥ 65 years and discharge HF drugs are most often not applied at dose levels acknowledged to provide prognostic benefit. This study therefore aims to investigate the treatment effect size of discharge HF drugs in old HHF patients., Methods: Drugs are analyzed according to pharmacological class. Individual discharge HF drug dose is reported as percentage of guidelines-recommended target dose. Primary endpoint was 1-year all-cause mortality (ACM) after discharge; the secondary endpoint combined 1-year ACM and first cardiovascular hospitalization within 1 year after discharge. Comparison between 65-80 years and > 80 years old study participants tested the relative treatment effect size as a function of respective age group., Results: The 875 consecutive HHF patients had a median age of 82 years [76-87 years]; 48.6 % were females. Betablocker and diuretic treatment did not change the incidence of endpoints. Inhibition of the renin-angiotensin system (RASi), when compared to no treatment, decreased the incidence of endpoints both at the 1-25 % and the > 25 % target dose level. Antagonists of the mineralocorticoid receptor (MRA), when compared to no treatment, decreased the secondary endpoint at the 1-25 % target dose level but not at the > 25 % target dose level. The relative treatment effect size of RASi or MRA corresponded between the age strata for both endpoints., Conclusion: Low-dose RASi and MRA had beneficial effects in these old HHF patients., Competing Interests: Disclosure No disclosures., (Copyright © 2022 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

(1) Background: Heart failure (HF) is a complex disease and one of the major causes of morbidity and mortality in the world. The renin-angiotensin system (RAS) may contribute to the pathogenesis of HF. (2) Aim: To investigate the association of RAS key genetic variants, rs5051 (A-6G) in the gene encoding angiotensinogen ( AGT ), rs4646994 (I/D) in the gene for angiotensin I converting enzyme ( ACE ), and rs5186 (A1166C) in the gene encoding type 1 receptor for angiotensin II ( AGTR1 ), with the HF risk in the cohort of Polish patients. (3) Methods: The study group consisted of 415 patients that were diagnosed with HF, while the control group comprised of 152 healthy individuals. Genomic DNA were extracted from blood and genotyping was carried out using either PCR or PCR-RFLP for ACE or AGT and AGTR1 variants, respectively. (4) Results: No association has been found between the I/D ACE and heart failure. The HF risk was significantly higher for AG AGT heterozygotes (overdominance: AG versus AA + GG) and for carriers of the G AGT allele in codominant and dominant modes of inheritance. However, the risk of HF was significantly lower in the carriers of at least one C AGTR1 allele (AC or CC genotypes) or in AC AGTR1 heterozygotes (overdominant mode). There was a significant relationship for AGT and HF patients in NYHA Class I-II for whom the risk was higher for the carriers of the G allele, and for the AG heterozygotes. There was also a significant interaction between heterozygote advantage of AGT and BMI increasing the risk for HF. (5) Conclusion: Our results suggest that the A(-6)G AGT polymorphism may be associated with HF in the Polish population and the HF risk seems to be modulated by the A1166C AGTR1 polymorphism.

Background: Heterogeneity of heart failure (HF) with preserved ejection fraction (HFpEF) would contribute to the difficulty in identifying effective treatments, and interest in the phenogrouping of HFpEF as a potential means for predicting patients who respond to cardioprotective drugs has been increasing., Methods: We studied 468 first-hospitalized HFpEF patients among 1971 acute-hospitalized HF patients from KUNIUMI Registry Acute Cohort. The primary endpoint was defined as HF-rehospitalization and cardiovascular death over a median follow-up period of 508 days., Results: In HFpEF patients with left ventricular hypertrophy (LVH), patients prescribed renin-angiotensin-aldosterone-system (RAAS) inhibitors had similar outcomes compared to those without (HR, 0.77; 95% CI 0.51-1.16; p = 0.21), and the outcome was also similar between patients with and without RAAS inhibitors' prescription in HFpEF patients without LVH. Moreover, in HFpEF patients with LVH and mild-moderate chronic kidney disease (CKD), which was determined as an estimated glomerular filtration rate (eGFR) of 30-60 mL/min/1.73 m 2 , patients prescribed RAAS inhibitors had significantly favorable outcomes compared to those without (HR 0.39; 95% CI 0.19-0.80; p = 0.01). In HFpEF patients with LVH and severe CKD, which was defined as eGFR <30 mL/min/1.73 m 2 , the outcome was similar between patients with and without RAAS inhibitor prescription. Multivariable Cox regression analysis showed that the prescription of RAAS inhibitors was the only independent predictor of outcome in HFpEF patients with LVH and mild-moderate CKD (HR 0.49; 95% CI 0.25-0.94; p = 0.03)., Conclusions: Our findings showed the importance of HFpEF phenogrouping for identifying effective pharmacological treatments., Competing Interests: Declaration of Competing Interest H.T. is a consultant for AstraZeneca plc and Ono Pharmaceutical Company, Limited. K.H. has received research funding from Daiichi Sankyo Company, Limited, Actelion Pharmaceuticals Japan, Terumo Corporation, Abbott Vascular Japan, Otsuka Pharmaceutical Company, Limited, Kowa Company, Limited, Takeda Pharmaceutical Company Limited, Nihon Medi-Physics Company Limited, Novartis Pharma Company Limited, Bayer Company Limited, Biotronic Japan Company Limited, FUJIFILM Toyama Chemical Company Limited, Medtronic Japan Company Limited, Sysmex Company Limited. The remaining authors have no conflicts of interest to declare., (Copyright © 2021. Published by Elsevier Ltd.)

Objective: To describe the clinical outcomes of COVID-19 in a racially diverse sample from the US Southeast and examine the association of renin-angiotensin-aldosterone system (RAAS) inhibitor use with COVID-19 outcome., Design, Setting, Participants: This study is a retrospective cohort of 1024 patients with reverse-transcriptase PCR-confirmed COVID-19 infection, admitted to a 1242-bed teaching hospital in Alabama. Data on RAAS inhibitors use, demographics and comorbidities were extracted from hospital medical records., Primary Outcomes: In-hospital mortality, a need of intensive care unit, respiratory failure, defined as invasive mechanical ventilation (iMV) and 90-day same-hospital readmissions., Results: Among 1024 patients (mean (SD) age, 57 (18.8) years), 532 (52.0%) were African Americans, 514 (50.2%) male, 493 (48.1%) had hypertension, 365 (36%) were taking RAAS inhibitors. During index hospitalisation (median length of stay of 7 (IQR (4-15) days) 137 (13.4%) patients died; 170 (19.2%) of survivors were readmitted. RAAS inhibitor use was associated with lower in-hospital mortality (adjusted HR, 95% CI (0.56, (0.36 to 0.88), p=0.01) and no effect modification by race was observed (p for interaction=0.81). Among patients with hypertension, baseline RAAS use was associated with reduced risk of iMV, adjusted OR, 95% CI (aOR 0.58, 95% CI 0.36 to 0.95, p=0.03). Patients with heart failure were twice as likely to die from COVID-19, compared with patients without heart failure., Conclusions: In a retrospespective study of racially diverse patients, hospitalised with COVID-19, prehospitalisation use of RAAS inhibitors was associated with 40% reduction in mortality irrespective of race., Competing Interests: Competing interests: ALC reports serving as a consultant for Bayer. EAJ reports research funding from NIH, and Amgen; editorial board membership: Circulation: Cardiovascular Quality and Outcomes; consulting: American College of Cardiology and McKesson; Expert witness for DeBlase Brown Everly.; and royalties for UpToDate. MMS reports research funding from Amgen. SO reports research funding from Bayer, CinCor Pharma, George Medicine and Idorsia Pharmaceuticals. Other authors report no conflict of interest, (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Cardiorenal syndrome (CRS), a clinical syndrome involving multiple pathological mechanisms, exhibits high morbidity and mortality. According to the primary activity of the disease, CRS can be divided into cardiorenal syndrome (type I and type II), renal heart syndrome (type III and type IV), and secondary heart and kidney disease (type V). The renin-angiotensin-aldosterone system (RAAS) is an important humoral regulatory system of the body that exists widely in various tissues and organs. As a compensatory mechanism, the RAAS is typically activated to participate in the regulation of target organ function. RAAS activation plays a key role in the pathogenesis of CRS. The RAAS induces the onset and development of CRS by mediating oxidative stress, uremic toxin overload, and asymmetric dimethylarginine production. Research on the mechanism of RAAS-induced CRS can provide multiple intervention methods that are of great significance for reducing end-stage organ damage and further improving the quality of life of patients with CRS., Competing Interests: There is no conflict of interest in the article., (Copyright © 2022 Kexin Ma et al.)

Despite advances in the management of iron deficiency in heart failure (HF), the mechanisms underlying the effects of treatment remain to be established. Iron distribution and metabolism in HF pathogenesis need to be clarified. We used a porcine tachycardia-induced cardiomyopathy model to find out how HF development influences hepatic and myocardial iron storing, focusing on ferritin, the main iron storage protein. We found that cumulative liver congestion (due to the decrease of heart function) overwhelms its capacity to recycle iron from erythrocytes. As a consequence, iron is trapped in the liver as poorly mobilized hemosiderin. What is more, the ferritin-bound Fe 3+ (reflecting bioavailable iron stores), and assembled ferritin (reflecting ability to store iron) are decreased in HF progression in the liver. We demonstrate that while HF pigs show iron deficiency indices, erythropoiesis is enhanced. Renin-angiotensin-aldosterone system activation and hepatic hepcidin suppression might indicate stress erythropoiesisinduced in HF. Furthermore, assembled ferritin increases but ferritin-bound Fe 3+ is reduced in myocardium, indicating that a failing heart increases the iron storage reserve but iron deficiency leads to a drop in myocardial iron stores. Together, HF in pigs leads to down-regulated iron bioavailability and reduced hepatic iron storage making iron unavailable for systemic/cardiac needs.

Aims: In patients with current or a history of hyperkalaemia, treatment with renin-angiotensin-aldosterone system inhibitors (RAASi) is often compromised. Patiromer, a novel potassium (K + ) binder, may improve serum K + levels and adherence to RAASi., Methods: The DIAMOND trial will enroll ∼820 patients with heart failure with reduced ejection fraction (HFrEF; ejection fraction ≤40%). Patients meeting the screening criteria will enter a single-blinded run-in phase where they will be started or continued on a mineralocorticoid receptor antagonist (MRA) titrated to 50 mg/day and other RAASi therapy to ≥50% target dose, and patiromer. Patiromer will be titrated up to a maximum three packs/day (8.4 g/pack) to achieve optimal doses of RAASi without hyperkalaemia. The run-in phase will last up to 12 weeks, following which patients will undergo double-blind randomization in a 1:1 ratio to receive either continued patiromer or placebo (patiromer withdrawal). The primary endpoint is the mean difference in serum K + from randomization between patiromer and placebo arms. Secondary endpoints will include hyperkalaemia events with K + value >5.5 mEq/L, durable enablement of MRA at target dose, investigator-reported adverse events of hyperkalaemia, hyperkalaemia-related clinical endpoints and an overall RAASi use score (using a 0-8-point scale) comprising all-cause death, occurrence of cardiovascular hospitalization or usage of comprehensive heart failure medication., Conclusion: The DIAMOND trial is designed to determine if patiromer can favourably impact K + control in patients with HFrEF with hyperkalaemia or a history of hyperkalaemia leading to RAASi therapy compromise, and in turn improve RAASi use., (© 2021 The Authors. European Journal of Heart Failure published by John Wiley & Sons Ltd on behalf of European Society of Cardiology.)

Introduction: The present study examined the possible estimation of plasma renin activity (PRA) by serum and urinary concentrations of chloride versus sodium in acute and chronic heart failure (HF)., Methods: Data from 29 patients with acute HF (48% men; 80.3 ± 12 years) and 26 patients with recovery of HF after decongestive therapy (50% men; 81.2 ± 12 years) were analyzed. Blood and urine samples were obtained immediately before decongestive therapy in acute HF patients. Clinical tests included peripheral blood tests, serum and spot urinary electrolytes, and plasma neurohormones. Sodium- or chloride-related indices included serum ([sNa+] or [sCl-]) and urinary ([uNa+] or [uCl-]) concentrations, their differences, and their ratio. Linear regression analysis was used for correlation coefficients., Results: PRA levels higher than the normal range were detected in only 5 (17%) of 29 patients with acute HF, but in as many as 11 (42%) of 26 patients with chronic HF. In the 29 patients with acute HF, all the chloride- and sodium-related indices except for [sNa+] were correlated with PRA: the [sCl-]/[uCl-] ratio was best correlated with PRA (R2 = 0.84, p < 0.0001) followed by the [sNa+]/[uNa+] ratio (R2 = 0.64, p < 0.0001). In the 26 patients with chronic HF, however, both the [sCl-] (R2 = 0.36, p = 0.001) and [sNa+] (R2 = 0.22, p = 0.016) were only weakly correlated with PRA., Conclusion: In acute HF, chloride-related indices derived from serum and urinary concentrations were firmly associated with PRA or better than sodium-related indices. In chronic HF, either chloride- or sodium-related indices were not firmly associated with PRA, presumably due to influence of cardiovascular medication., (© 2022 The Author(s). Published by S. Karger AG, Basel.)

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Background: Renin-angiotensin-aldosterone system inhibitors (RAASi) improve prognosis in patients with heart failure with reduced ejection fraction (HFrEF), but suboptimal dosing or discontinuation of these medications often occurs due to RAASi-associated hyperkalaemia. We established a nephrology-led hyperkalaemia clinic to oversee prescribing of patiromer, an oral potassium binder, to facilitate RAASi optimization., Methods: The clinic was established in July 2019 at a nephrology tertiary centre in the UK. Patients with HFrEF who were unable to increase RAASi dosage due to hyperkalaemia were referred to the clinic, where all patients commenced patiromer 8.4 g daily. RAASi adjustments were deferred to the referring teams. Study outcomes included the percentage of patients who achieved a RAASi dose increase and the proportion of patients with normokalaemia at follow-up. Outcomes were evaluated until 1 May 2021., Results: A total of 34 patients were reviewed in the clinic between July 2019 and December 2020. Mean age was 71.6 years (±10.6 years), 56% had diabetes, and 71% had chronic kidney disease stages 3a-5; mean estimated glomerular filtration rate was 56 mL/min/1.73 m2 (±21 mL/min/1.73 m2). During follow-up, 13 patients discontinued patiromer (6 of whom did so due to gastrointestinal side effects) and were discharged; 2 patients died from non-hyperkalaemia-related illness; one switched to an alternative potassium binder. Over a mean follow-up of 13.4 months (±5.8 months), 17 of the 20 patients (85%) who continued with a potassium binder achieved a RAASi dose increase, with 4 patients (20%) receiving maximal dosages. This was attained by achieving normokalaemia during follow-up. No patients required magnesium supplementation. Of the 19 patients on patiromer, 12 continued this therapy for more than 12 months and 4 received it safely for 20 months., Discussion/conclusion: Patiromer prescribing in a nephrology-led hyperkalaemia clinic facilitated RAASi up-titration in patients with HFrEF by controlling potassium levels., (© 2022 The Author(s). Published by S. Karger AG, Basel.)

Aims: Rheumatic heart disease (RHD) remains a major global health problem. Renin-angiotensin-aldosterone system inhibitors (RAASi) are commonly administered in the treatment of cardiovascular disease, but its role in RHD patients is still limited. We performed a retrospective study to determine the effect of RAASi on long-term outcomes for RHD patients., Methods and Results: A 1:1 propensity score matching was implemented to balance baseline characteristics between groups RAASi and non-RAASi. Cox proportional hazards regression model was used to investigate the associations of RAASi with the risks of all-cause mortality, cardiovascular death (CVD), and cerebrovascular death. Binary logistic regression analysis was used to evaluate the associations of RAASi with the risks of 1, 3, and 5 year heart failure (HF) rehospitalization, new-onset atrial fibrillation (AF), and new-onset stroke. A total of 734 RHD patients were enrolled as study participants; nearly half of these participants had combined valve damage (54.4%), worse New York Heart Association functional class status (III and IV, 55.2%), surgical treatment (54.2%), and AF (65.0%). After propensity score matching, 514 RHD patients were finally analysed. RAASi treatment was associated with decreased risks of all-cause mortality [adjusted hazard ratio (HR) = 0.52, 95% confidence interval (CI): 0.37-0.73, P < 0.001], CVD (adjusted HR = 0.48, 95% CI: 0.30-0.76, P = 0.002), and cerebrovascular death (adjusted HR = 0.22, 95% CI: 0.08-0.60, P = 0.003). Further subgroup analysis showed that RAASi treatment was associated with decreased risks of all-cause mortality (adjusted HR = 0.50, 95% CI: 0.31-0.79, P = 0.004), CVD (adjusted HR = 0.48, 95% CI: 0.25-0.91, P = 0.025), and cerebrovascular death (adjusted HR = 0.19, 95% CI: 0.05-0.65, P = 0.008) in RHD patients without surgical treatment, and better effect was observed in RHD patients with surgical treatment on the risks of all-cause mortality (adjusted HR = 0.47, 95% CI: 0.26-0.85, P = 0.012) and CVD (adjusted HR = 0.43, 95% CI: 0.21-0.90, P = 0.024) except cerebrovascular death (adjusted HR = 0.52, 95% CI: 0.08-3.36, P = 0.491). RAASi treatment was associated with decreased HF rehospitalization risk of 1 year [adjusted odds ratio (OR) = 0.38, 95% CI: 0.23-0.61, P < 0.001], 3 year (adjusted OR = 0.43, 95% CI: 0.28-0.68, P < 0.001), and 5 year (adjusted OR = 0.48, 95% CI: 0.30-0.77, P = 0.002) as well as new-onset AF risk (adjusted OR = 0.38, 95% CI: 0.21-0.68, P = 0.001). RAASi treatment had nothing to do with new-onset stroke risk (adjusted OR = 0.80, 95% CI: 0.47-1.38, P = 0.428)., Conclusion: Renin-angiotensin-aldosterone system inhibitor treatment was significantly associated with decreased risks of mortality, HF rehospitalization, and new-onset AF in RHD patients in median 5.9 year follow-up., (© 2021 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of European Society of Cardiology.)

Background Sacubitril/valsartan, a first-in-class angiotensin receptor neprilysin inhibitor, received US Food and Drug Administration approval in 2015 for heart failure with reduced ejection fraction (HFrEF). Our objective was to describe the sacubitril/valsartan initiation rate, associated characteristics, and 6-month follow-up dosing among veterans with HFrEF who are renin-angiotensin-aldosterone system inhibitor (RAASi) naïve. Methods and Results Retrospective cohort study of veterans with HFrEF who are RAASi naïve defined as left ventricular ejection fraction (LVEF) ≤40%; ≥1 in/outpatient heart failure visit, first RAASi (sacubitril/valsartan, angiotensin-converting enzyme inhibitor [ACEI]), or angiotensin-II receptor blocker [ARB]) fill from July 2015 to June 2019. Characteristics associated with sacubitril/valsartan initiation were identified using Poisson regression models. From July 2015 to June 2019, we identified 3458 sacubitril/valsartan and 29 367 ACEI or ARB initiators among veterans with HFrEF who are RAASi naïve. Sacubitril/valsartan initiation increased from 0% to 26.5%. Sacubitril/valsartan (versus ACEI or ARB) initiators were less likely to have histories of stroke, myocardial infarction, or hypertension and more likely to be older and have diabetes mellitus and lower LVEF. At 6-month follow-up, the prevalence of ≥50% target daily dose for sacubitril/valsartan, ACEI, and ARB initiators was 23.5%, 43.2%, and 47.1%, respectively. Conclusions Sacubitril/valsartan initiation for HFrEF in the Veterans Administration increased in the 4 years immediately following Food and Drug Administration approval. Sacubitril/valsartan (versus ACEI or ARB) initiators had fewer baseline cardiovascular comorbidities and the lowest proportion on ≥50% target daily dose at 6-month follow-up. Identifying the reasons for lower follow-up dosing of sacubitril/valsartan could support guideline recommendations and quality improvement strategies for patients with HFrEF.

Objective: The effect of renin-angiotensin system inhibitors (RASIs) in patients with heart failure (HF) and atrial fibrillation (AF) remains unclear. This study aimed to investigate associations between RASI use and all-cause mortality and cardiovascular outcomes in patients with AF and HF., Methods: Using data from the China Atrial Fibrillation Registry study, we included 938 patients with AF and HF with a left ventricular ejection fraction <50%. Cox regression models for RASIs vs. non-RASIs with all-cause mortality as the primary outcome were fitted in a 1:1 propensity score-matched cohort. A sensitivity analysis was performed by using a multivariable time-dependent Cox regression model. As an internal control, we assessed the relation between β-blocker use and all-cause mortality., Results: During a mean follow-up of 35 months, the risk of all-cause mortality was similar in RASI users compared with non-users (hazard ratio: 0.92; 95% confidence interval: 0.67-1.26). Similar results were obtained in the sensitivity analysis. In contrast, β-blocker use was associated with significantly lower all-cause mortality in the same population., Conclusions: RASI use was not associated with better outcomes in patients with AF and HF in this prospective cohort, which raises questions about their value in this specific subset.Trail Registration: ChiCTR-OCH-13003729.

Aims: Results of experimental studies have indicated the possibility of muscle and bone mass being negatively regulated by renin-angiotensin system (RAS) activation, but that possibility has not been analysed in patients with heart failure (HF)., Methods and Results: Data for HF patients who received a dual-energy X-ray absorptiometry scan in our hospital were reviewed. Propensity scores for the use of RAS inhibitors (RASIs) were calculated using a multivariate logistic regression model to minimize selection bias. One hundred sixty pairs of patients were extracted. Plasma aldosterone concentration was significantly lower in the RASIs group than in the no-RASIs group (119 [IQR 71-185] vs. 94 [IQR 60-131] pg/mL, P = 0.003), confirming RAS inhibition in the RASIs group. Skeletal muscle mass index tended to be higher in the RASIs group than in the non-RASIs group (15.6 [IQR 14.0-17.2] vs. 15.0 [IQR 13.3-16.6] pg/mL, P = 0.065). The proportion of patients with muscle wasting, defined as appendicular skeletal muscle mass indexes of <7.00 and <5.40 kg/m 2 for males and females, respectively, was significantly lower in the RASIs group than in the non-RASIs group (53% vs. 64%, P = 0.041). Multivariate logistic regression analysis showed that the no use of RASIs was associated with presence of muscle wasting independently of age, presence of diabetes, renal function, and severity of HF. Bone mineral densities and proportions of patients with osteoporosis were similar in the two groups., Conclusions: Renin-angiotensin system inhibition is associated with a lower prevalence of muscle wasting in HF patients independently of established risk factors., (© 2021 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of European Society of Cardiology.)

Aims: Recently, dipeptidyl peptidase 3 (DPP3) has been discovered as the peptidase responsible for cleavage of angiotensin (1-7) [Ang (1-7)]. Ang (1-7) is part of the angiotensin-converting enzyme-Ang (1-7)-Mas pathway which is considered to antagonize the renin-angiotensin-aldosterone system (RAAS). Since DPP3 inhibits the counteracting pathway of the RAAS, we hypothesize that DPP3 might be deleterious in the setting of heart failure. However, no data are available on DPP3 in chronic heart failure. We therefore investigated the clinical characteristics and outcome related to elevated DPP3 concentrations in patients with worsening heart failure., Methods and Results: Dipeptidyl peptidase 3 was measured in 2156 serum samples of patients with worsening heart failure using luminometric immunoassay (DPP3-LIA) by 4TEEN4 Pharmaceuticals GmbH, Hennigsdorf, Germany. Predictors of DPP3 levels were selected using multiple linear regression with stepwise backward selection. Median DPP3 concentration was 11.45 ng/mL with a range from 2.8 to 84.9 ng/mL. Patients with higher DPP3 concentrations had higher renin [78.3 (interquartile range, IQR 26.3-227.7) vs. 120.7 IU/mL (IQR 34.74-338.9), P < 0.001, for Q1-3 vs. Q4] and aldosterone [88 (IQR 44-179) vs. 116 IU/mL (IQR 46-241), P < 0.001, for Q1-3 vs. Q4] concentrations. The strongest independent predictors for higher concentration of DPP3 were log-alanine aminotransferase, log-total bilirubin, the absence of diabetes, higher osteopontin, fibroblast growth factor-23 and N-terminal pro-B-type natriuretic peptide concentrations (all P < 0.001). In univariable survival analysis, DPP3 was associated with mortality and the combined endpoint of death or heart failure hospitalization (P < 0.001 for both). After adjustment for confounders, this association was no longer significant., Conclusions: In patients with worsening heart failure, DPP3 is a marker of more severe disease with higher RAAS activity. It may be deleterious in heart failure by counteracting the Mas receptor pathway. Procizumab, a specific antibody against DPP3, might be a potential future treatment option for patients with heart failure., (© 2021 The Authors. European Journal of Heart Failure published by John Wiley & Sons Ltd on behalf of European Society of Cardiology.)

Sodium restriction is often recommended in heart failure (HF) to block symptomatic edema, despite limited evidence for benefit. However, a low-sodium diet (LSD) activates the classical renin-angiotensin-aldosterone system (RAAS), which may adversely affect HF progression and mortality in patients with dilated cardiomyopathy (DCM). We performed a randomized, blinded pre-clinical trial to compare the effects of a normal (human-equivalent) sodium diet and a LSD on HF progression in a normotensive model of DCM in mice that has translational relevance to human HF. The LSD reduced HF progression by suppressing the development of pleural effusions ( p < 0.01), blocking pathological increases in systemic extracellular water ( p < 0.001) and prolonging median survival (15%, p < 0.01). The LSD activated the classical RAAS by increasing plasma renin activity, angiotensin II and aldosterone levels. However, the LSD also significantly up-elevated the counter-regulatory RAAS by boosting plasma angiotensin converting enzyme 2 (ACE2) and angiotensin (1-7) levels, promoting nitric oxide bioavailability and stimulating 3'-5'-cyclic guanosine monophosphate (cGMP) production. Plasma HF biomarkers associated with poor outcomes, such as B-type natriuretic peptide and neprilysin were decreased by a LSD. Cardiac systolic function, blood pressure and renal function were not affected. Although a LSD activates the classical RAAS system, we conclude that the LSD delayed HF progression and mortality in experimental DCM, in part through protective stimulation of the counter-regulatory RAAS to increase plasma ACE2 and angiotensin (1-7) levels, nitric oxide bioavailability and cGMP production.

Background: The myocardium exhibits an adaptive tissue-specific renin-angiotensin system (RAS), and local dysbalance may circumvent the desired effects of pharmacologic RAS inhibition, a mainstay of heart failure with reduced ejection fraction (HFrEF) therapy., Objectives: This study sought to investigate human myocardial tissue RAS regulation of the failing heart in the light of current therapy., Methods: Fifty-two end-stage HFrEF patients undergoing heart transplantation (no RAS inhibitor: n = 9; angiotensin-converting enzyme [ACE] inhibitor: n = 28; angiotensin receptor blocker [ARB]: n = 8; angiotensin receptor neprilysin-inhibitor [ARNi]: n = 7) were enrolled. Myocardial angiotensin metabolites and enzymatic activities involved in the metabolism of the key angiotensin peptides angiotensin 1-8 (AngII) and Ang1-7 were determined in left ventricular samples by mass spectrometry. Circulating angiotensin concentrations were assessed for a subgroup of patients., Results: AngII and Ang2-8 (AngIII) were the dominant peptides in the failing heart, while other metabolites, especially Ang1-7, were below the detection limit. Patients receiving an ARB component (i.e., ARB or ARNi) had significantly higher levels of cardiac AngII and AngIII (AngII: 242 [interquartile range (IQR): 145.7 to 409.9] fmol/g vs 63.0 [IQR: 19.9 to 124.1] fmol/g; p < 0.001; and AngIII: 87.4 [IQR: 46.5 to 165.3] fmol/g vs 23.0 [IQR: <5.0 to 59.3] fmol/g; p = 0.002). Myocardial AngII concentrations were strongly related to circulating AngII levels. Myocardial RAS enzyme regulation was independent from the class of RAS inhibitor used, particularly, a comparable myocardial neprilysin activity was observed for patients with or without ARNi. Tissue chymase, but not ACE, is the main enzyme for cardiac AngII generation, whereas AngII is metabolized to Ang1-7 by prolyl carboxypeptidase but not to ACE2. There was no trace of cardiac ACE2 activity., Conclusions: The failing heart contains considerable levels of classical RAS metabolites, whereas AngIII might be an unrecognized mediator of detrimental effects on cardiovascular structure. The results underline the importance of pharmacologic interventions reducing circulating AngII actions, yet offer room for cardiac tissue-specific RAS drugs aiming to limit myocardial AngII/AngIII peptide accumulation and actions., Competing Interests: Funding Support and Author Disclosures This project has been funded by the Anniversary Fund of the Österreichische Nationalbank (OeNB). Drs. Poglitsch and Domenig are employed by Attoquant Diagnostics, a company that received payments for RAS Fingerprint and enzyme activity measurements. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2021 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)