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.

Association Between Use of Sodium-Glucose Cotransporter-2 Inhibitors or Angiotensin Receptor-Neprilysin Inhibitor and the Risk of Atherosclerotic Cardiovascular Disease With Coexisting Diabetes and Heart Failure.

PURPOSE: This study was to investigate the association between the use of Sodium-glucose Cotransporter-2 inhibitors (SGLT2i) or angiotensin receptor-neprilysin inhibitor (ARNI; ie, Sacubitril + valsartan, Product name ENTRESTO) and the risk of atherosclerotic cardiovascular disease (ASCVD) in patients with coexisting diabetes and heart failure. Specifically, the study compared outcomes between patients using SGLT2i or valsartan + sacubitril and those not using these medications. METHODS: This study utilized data from the National Health Insurance Research Database (NHIRD) from 2017 to 2018. The case group consisted of 8691 patients with coexisting diabetes and heart failure who did not use SGLT2i or Entresto, while the control group consisted of 8691 patients with coexisting diabetes and heart failure who used SGLT2i or Entresto. The primary outcome was ASCVD, including a composite of cardiovascular death and hospitalization for worsening heart failure. Secondary outcomes included all-cause death, cause of cardiovascular death, and recurrence of heart failure, non-fatal myocardial infarction, non-fatal stroke (including ischemic stroke and hemorrhagic stroke) and new renal replacement therapy. RESULTS: The study found that the use of SGLT2 inhibitors or ARNI was associated with a lower risk of ASCVD in patients with coexisting diabetes and heart failure. CONCLUSION: The study suggests that the use of SGLT2 inhibitors, alone or in combination with Entresto, may be effective in reducing the risk of ASCVD and its associated adverse outcomes in patients with diabetes and heart failure. This finding has important implications for the management of these conditions.

Decreased expression of the NLRP6 inflammasome is associated with increased intestinal permeability and inflammation in obesity with type 2 diabetes.

BACKGROUND: Obesity-associated dysfunctional intestinal permeability contributes to systemic chronic inflammation leading to the development of metabolic diseases. The inflammasomes constitute essential components in the regulation of intestinal homeostasis. We aimed to determine the impact of the inflammasomes in the regulation of gut barrier dysfunction and metabolic inflammation in the context of obesity and type 2 diabetes (T2D). METHODS: Blood samples obtained from 80 volunteers (n = 20 normal weight, n = 21 OB without T2D, n = 39 OB with T2D) and a subgroup of jejunum samples were used in a case-control study. Circulating levels of intestinal damage markers and expression levels of inflammasomes as well as their main effectors (IL-1ß and IL-18) and key inflammation-related genes were analyzed. The impact of inflammation-related factors, different metabolites and Akkermansia muciniphila in the regulation of inflammasomes and intestinal integrity genes was evaluated. The effect of blocking NLRP6 by using siRNA in inflammation was also studied. RESULTS: Increased circulating levels (P < 0.01) of the intestinal damage markers endotoxin, LBP, and zonulin in patients with obesity decreased (P < 0.05) after weight loss. Patients with obesity and T2D exhibited decreased (P < 0.05) jejunum gene expression levels of NLRP6 and its main effector IL18 together with increased (P < 0.05) mRNA levels of inflammatory markers. We further showed that while NLRP6 was primarily localized in goblet cells, NLRP3 was localized in the intestinal epithelial cells. Additionally, decreased (P < 0.05) mRNA levels of Nlrp1, Nlrp3 and Nlrp6 in the small intestinal tract obtained from rats with diet-induced obesity were found. NLRP6 expression was regulated by taurine, parthenolide and A. muciniphila in the human enterocyte cell line CCL-241. Finally, a significant decrease (P < 0.01) in the expression and release of MUC2 after the knockdown of NLRP6 was observed. CONCLUSIONS: The increased levels of intestinal damage markers together with the downregulation of NLRP6 and IL18 in the jejunum in obesity-associated T2D suggest a defective inflammasome sensing, driving to an impaired epithelial intestinal barrier that may regulate the progression of multiple obesity-associated comorbidities.

Angiotensin Receptor-Neprilysin Inhibition in Patients With STEMI vs NSTEMI.

BACKGROUND: Patients who sustain an acute myocardial infarction (AMI), including ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI), remain at high risk for heart failure (HF), coronary events, and death. Angiotensin-converting enzyme inhibitors have been shown to significantly decrease the risk for cardiovascular events in both STEMI and NSTEMI patients. OBJECTIVES: The objectives were to determine whether angiotensin-receptor blockade and neprilysin inhibition with sacubitril/valsartan, compared with ramipril, has impact on reducing cardiovascular events according to the type of AMI. METHODS: The PARADISE-MI (Prospective ARNI versus ACE inhibitor trial to DetermIne Superiority in reducing heart failure Events after Myocardial Infarction) trial enrolled patients with AMI complicated by left ventricular dysfunction and/or pulmonary congestion and at least 1 risk-enhancing factor. Patients were randomized to either sacubitril/valsartan or ramipril. The primary endpoint was death from cardiovascular causes or incident HF. In this prespecified analysis, we stratified patients according to AMI type. RESULTS: Of 5,661 enrolled patients, 4,291 (75.8%) had STEMI. These patients were younger and had fewer comorbidities and cardiovascular risk factors than NSTEMI patients. After adjustment for potential confounders, the risk for the primary outcome was marginally higher in NSTEMI vs STEMI patients (adjusted HR: 1.19; 95% CI: 1.00-1.41), with borderline statistical significance (P = 0.05). The primary composite outcome occurred at similar rates in patients randomized to sacubitril/valsartan vs ramipril in STEMI (10% vs 12%; HR: 0.87; 95% CI: 0.73-1.04; P = 0.13) and NSTEMI patients (17% vs 17%; HR: 0.97; 95% CI: 0.75-1.25; P = 0.80; P interaction = 0.53). CONCLUSIONS: Compared with ramipril, sacubitril/valsartan did not significantly decrease the risk for cardiovascular death and HF in patients with AMI complicated by left ventricular dysfunction, irrespective of the type of AMI. (Prospective ARNI vs ACE Inhibitor Trial to Determine Superiority in Reducing Heart Failure Events After MI; NCT02924727).

Association of Angiotensin II Receptor Type 1 and Endothelin-1 Receptor Type A Agonistic Autoantibodies With Adverse Remodeling and Cardiovascular Events After Acute Myocardial Infarction.

BACKGROUND: The left ventricular remodeling (LVR) process has limited the effectiveness of therapies after myocardial infarction. The relationship between autoantibodies activating AT1R-AAs (angiotensin II receptor type 1-AAs) and ETAR-AAs (autoantibodies activating endothelin-1 receptor type A) with myocardial infarction has been described. Among patients with ST-segment-elevation myocardial infarction, we investigated the relationship between these autoantibodies with LVR and subsequent major adverse cardiac events. METHODS AND RESULTS: In this prospective observational study, we included 131 patients with ST-segment-elevation myocardial infarction (61±11 years of age, 112 men) treated with primary percutaneous coronary intervention. Within 48 hours of admission, 2-dimensional transthoracic echocardiography was performed, and blood samples were obtained. The seropositive threshold for AT1R-AAs and ETAR-AAs was >10 U/mL. Patients were followed up at 6 months, when repeat transthoracic echocardiography was performed. The primary end points were LVR, defined as a 20% increase in left ventricular end-diastolic volume index, and major adverse cardiac event occurrence at follow-up, defined as cardiac death, nonfatal re-myocardial infarction, and hospitalization for heart failure. Forty-one (31%) patients experienced LVR. The prevalence of AT1R-AAs and ETAR-AAs seropositivity was higher in patients with versus without LVR (39% versus 11%, P<0.001 and 37% versus 12%, P=0.001, respectively). In multivariable analysis, AT1R-AAs seropositivity was significantly associated with LVR (odds ratio [OR], 4.66; P=0.002) and represented a risk factor for subsequent major adverse cardiac events (OR, 19.6; P=0.002). CONCLUSIONS: AT1R-AAs and ETAR-AAs are associated with LVR in patients with ST-segment-elevation myocardial infarction. AT1R-AAs are also significantly associated with recurrent major adverse cardiac events. These initial observations may set the stage for a better pathophysiological understanding of the mechanisms contributing to LVR and ST-segment-elevation myocardial infarction prognosis.

Angiotensin Receptor-Neprilysin Inhibition (Sacubitril/Valsartan) Reduces Structural Arterial Stiffness in Middle-Aged Mice.

BACKGROUND: Increasing arterial stiffness is a prominent feature of the aging cardiovascular system. Arterial stiffening leads to fundamental alterations in central hemodynamics with widespread detrimental implications for organ function resulting in significant morbidity and death, and specific therapies to address the underlying age-related structural arterial remodeling remain elusive. The present study investigates the potential of the recently clinically available dual angiotensin receptor-neprilysin inhibitor (ARNI) sacubitril/valsartan (LCZ696) to counteract age-related arterial fibrotic remodeling and stiffening in 1-year-old mice. METHODS AND RESULTS: Treatment of in 1-year-old mice with ARNI (sacubitril/valsartan), in contrast to angiotensin receptor blocker monotherapy (valsartan) and vehicle treatment (controls), significantly decreases structural aortic stiffness (as measured by in vivo pulse-wave velocity and ex vivo aortic pressure myography). This phenomenon appears, at least partly, independent of (indirect) blood pressure effects and may be related to a direct antifibrotic interference with aortic smooth muscle cell collagen production. Furthermore, we find aortic remodeling and destiffening due to ARNI treatment to be associated with improved parameters of cardiac diastolic function in aged mice. CONCLUSIONS: This study provides preclinical mechanistic evidence indicating that ARNI-based interventions may counteract age-related arterial stiffening and may therefore be further investigated as a promising strategy to improve cardiovascular outcomes in the elderly.

Estimating the clinical and budgetary impact of using angiotensin receptor neprilysin inhibitor as first line therapy in patients with HFrEF.

AIMS: Recent updates of international treatment guidelines for heart failure with reduced ejection fraction (HFrEF) differ regarding the use of angiotensin receptor neprilysin inhibitor (ARNI) as first-line treatment. The American Heart Association/American College of Cardiology/Heart Failure Society of America (AHA/ACC/HFSA) 2022 guidelines gives ARNI a Class IA recommendation for HFrEF patients while the European Society of Cardiology's guidelines are less clear when ARNI could be considered as first line treatment option in de novo patients. This study aimed to model the clinical and budgetary outcomes of implementing these guidelines, comparing conservative ARNI prescription patterns with less conservative in Sweden and in the United Kingdom. METHODS AND RESULTS: A health economic model was developed to compare different treatment patterns for HFrEF. Incident cohorts were included on an annual basis and followed over 10 years. The model included treatment specific all-cause mortality and hospitalization rates, as well as drug acquisition, monitoring, and hospitalization costs. Increasing the use of ARNI could lead to about 7000-12 300 life years gained and 2600-4600 hospitalizations prevented in Sweden. These health benefits come with an additional cost of 112-195 million euros. Similar results were estimated for the United Kingdom, albeit on a larger population. CONCLUSIONS: Increasing the proportion of patients receiving ARNI instead of angiotensin converting enzyme inhibitors as first-line treatment of HFrEF will lead to a considerable number of additional life years gained and prevented hospitalizations but with additional cost in terms of health care expenditure in Sweden and in the United Kingdom.

The antihypertensive action of C-phycocyanin is related to the prevention of angiotensin II-caused vascular dysfunction in chronic kidney disease.

C-phycocyanin (CPC) is a photosynthetic protein found in Arthrospira maxima with a nephroprotective and antihypertensive activity that can prevent the development of hemodynamic alterations caused by chronic kidney disease (CKD). However, the complete nutraceutical activities are still unknown. This study aims to determine if the antihypertensive effect of CPC is associated with preventing the impairment of hemodynamic variables through delaying vascular dysfunction. Twenty-four normotensive male Wistar rats were divided into four groups: (1) sham + 4 mL/kg/d vehicle (100 mM of phosphate buffer, PBS) administered by oral gavage (og), (2) sham + 100 mg/kg/d og of CPC, (3) CKD induced by 5/6 nephrectomy (CKD) + vehicle, (4) CKD + CPC. One week after surgery, the CPC treatment began and was administrated daily for four weeks. At the end treatment, animals were euthanized, and their thoracic aorta was used to determine the vascular function and expression of AT1, AT2, and Mas receptors. CKD-induced systemic arterial hypertension (SAH) and vascular dysfunction by reducing the vasorelaxant response of angiotensin 1-7 and increasing the contractile response to angiotensin II. Also, CKD increased the expression of the AT1 and AT2 receptors and reduced the Mas receptor expression. Remarkably, the treatment with CPC prevented SAH, renal function impairment, and vascular dysfunction in the angiotensin system. In conclusion, the antihypertensive activity of CPC is associated with avoiding changes in the expression of AT1, AT2, and Mas receptors, preventing vascular dysfunction development and SAH in rats with CKD.

Effect of hormone-induced plasma membrane phosphatidylinositol 4,5-bisphosphate depletion on receptor endocytosis suggests the importance of local regulation in phosphoinositide signaling.

Phosphatidylinositol 4,5-bisphosphate (PIP2) has been shown to be critical for the endocytosis of G protein-coupled receptors (GPCRs). We have previously demonstrated that depletion of PIP2 by chemically induced plasma membrane (PM) recruitment of a 5-phosphatase domain prevents the internalization of the ß2 adrenergic receptor (ß2AR) from the PM to early endosomes. In this study, we tested the effect of hormone-induced PM PIP2 depletion on ß2AR internalization using type-1 angiotensin receptor (AT1R) or M3 muscarinic acetylcholine receptor (M3R). We followed the endocytic route of ß2ARs in HEK 293T cells using bioluminescence resonance energy transfer between the receptor and endosome marker Rab5. To compare the effect of lipid depletion by different means, we created and tested an AT1R fusion protein that is capable of both recruitment-based and hormone-induced depletion methods. The rate of PM PIP2 depletion was measured using a biosensor based on the PH domain of phospholipase Cδ1. As expected, ß2AR internalization was inhibited when PIP2 depletion was evoked by recruiting 5-phosphatase to PM-anchored AT1R. A similar inhibition occurred when wild-type AT1R was activated by adding angiotensin II. However, stimulation of the desensitization/internalization-impaired mutant AT1R (TSTS/4A) caused very little inhibition of ß2AR internalization, despite the higher rate of measurable PIP2 depletion. Interestingly, inhibition of PIP2 resynthesis with the selective PI4KA inhibitor GSK-A1 had little effect on the change in PH-domain-measured PM PIP2 levels but did significantly decrease ß2AR internalization upon either AT1R or M3R activation, indicating the importance of a locally synthetized phosphoinositide pool in the regulation of this process.

Effect of angiotensin receptor neprilysin inhibitor on physical activity in patients with heart failure with reduced ejection fraction, monitored by implantable electronic device home monitoring.

AIMS: Angiotensin receptor neprilysin inhibitor (ARNI) therapy is a cornerstone in the treatment of heart failure with reduced ejection fraction (HFrEF), with significant improvement in mortality as well as morbidity and quality of life. However, maximal ARNI doses often result in hypotension. Recent studies with 'real world' experience suggest that lower doses of ARNI are as effective as higher doses.In order to evaluate the symptomatic effect of low-dose ARNI in HFrEF patients, we analyzed physical activity data obtained via home monitoring of patients with cardiac implantable electronic devices (CIEDs). METHODS: We retrospectively analyzed physical activity data obtained from HFrEF patients with CIED-active home monitoring during the years 2021-2022. Patients with ARNI therapy were further divided into subgroups according to the administered dose. Low-dose ARNI included doses of up to 24/26 mg sacubitril/valsartan daily. Intermediate dose and high dose included doses of 72/78-120/130 mg/day, and 144/156-194/206 mg/day, respectively. RESULTS: A total of 122 patients had home monitoring-compatible CIEDs and HFrEF during the study period. Sixty-four of these patients were treated with ARNI. Administration of low-dose ARNI resulted in a 20% increase in daily activity when compared with patients without ARNI treatment ( P  = 0.038). Change in physical activity of patients in the intermediate-dose and high-dose groups was not significant. Younger patients, patients with cardiac resynchronization therapy, and patients without diabetes mellitus were more physically active. CONCLUSION: Low-dose ARNI had a beneficial effect on physical activity in HFrEF patients. MH via CIED provided real-life objective data for patients' follow-up.

Interplay of Angiotensin Peptides, Vasopressin, and Insulin in the Heart: Experimental and Clinical Evidence of Altered Interactions in Obesity and Diabetes Mellitus.

The present review draws attention to the specific role of angiotensin peptides [angiotensin II (Ang II), angiotensin-(1-7) (Ang-(1-7)], vasopressin (AVP), and insulin in the regulation of the coronary blood flow and cardiac contractions. The interactions of angiotensin peptides, AVP, and insulin in the heart and in the brain are also discussed. The intracardiac production and the supply of angiotensin peptides and AVP from the systemic circulation enable their easy access to the coronary vessels and the cardiomyocytes. Coronary vessels and cardiomyocytes are furnished with AT1 receptors, AT2 receptors, Ang (1-7) receptors, vasopressin V1 receptors, and insulin receptor substrates. The presence of some of these molecules in the same cells creates good conditions for their interaction at the signaling level. The broad spectrum of actions allows for the engagement of angiotensin peptides, AVP, and insulin in the regulation of the most vital cardiac processes, including (1) cardiac tissue oxygenation, energy production, and metabolism; (2) the generation of the other cardiovascular compounds, such as nitric oxide, bradykinin (Bk), and endothelin; and (3) the regulation of cardiac work by the autonomic nervous system and the cardiovascular neurons of the brain. Multiple experimental studies and clinical observations show that the interactions of Ang II, Ang(1-7), AVP, and insulin in the heart and in the brain are markedly altered during heart failure, hypertension, obesity, and diabetes mellitus, especially when these diseases coexist. A survey of the literature presented in the review provides evidence for the belief that very individualized treatment, including interactions of angiotensins and vasopressin with insulin, should be applied in patients suffering from both the cardiovascular and metabolic diseases.

Pulmonary pressure-flow responses to exercise in heart failure treated with angiotensin receptor neprilysin inhibitor.

BACKGROUND: The role of the angiotensin receptor neprilysin inhibitor (ARNI) in cardiac function, particularly its impact on pulmonary circulation, remains underexplored. Recent studies have described abnormal mean pulmonary artery pressure (mPAP)-cardiac output (CO) responses as having the potential to assess the disease state. The aim of this study was to assess the effects of ARNI on pulmonary circulation in heart failure. We measured echocardiographic parameters post 6-min walk (6 MW) and compared the changes with baseline and follow-up. Our hypothesis was that pulmonary pressure-flow relationship of the pulmonary circulation obtained by 6 MW stress echocardiography would be improved with treatment. METHODS: We prospectively enrolled 39 heart failure patients and conducted the 6 MW test indoors. Post-6 MW echocardiography measured echocardiographic variables, and CO was derived from electric cardiometry. Individualized ARNI doses were optimized, with follow-up echocardiographic evaluations after 1 year. RESULTS: Left ventricular (LV) volume were significantly reduced (160.7 ± 49.6 mL vs 136.0 ± 54.3 mL, P < 0.001), and LV ejection fraction was significantly improved (37.6 ± 11.3% vs 44.9 ± 11.5%, P < 0.001). Among the 31 patients who underwent 6 MW stress echocardiographic study at baseline and 1 year later, 6 MW distance increased after treatment (380 m vs 430 m, P = 0.003). The ΔmPAP/ΔCO by 6 MW stress decreased with treatment (6.9 mmHg/L/min vs 2.8 mmHg/L/min, P = 0.002). The left atrial volume index was associated with the response group receiving ARNI treatment for pulmonary circulation. CONCLUSIONS: Initiation of ARNI was associated with improvement of left ventricular size and LVEF. Additionally, the 6 MW distance increased and the ΔmPAP/ΔCO was improved to within normal range with treatment.

Protective effect of novel angiotensin receptor neprilysin inhibitor S086 on target organ injury in spontaneously hypertensive rats.

BACKGROUND: Hypertension is a clinical syndrome characterized by elevated systemic arterial blood pressure associated with injury to the heart, kidney, brain, and other organs. Angiotensin receptor neprilysin inhibitors (ARNi), including angiotensin receptor blockers (ARBs) and neprilysin inhibitors (NEPi), have been shown to be safe and effective at reducing blood pressure and alleviating development of target organ injury. This study was used to develop S086 as a novel ARNi and conducted preclinical studies in animal models to evaluate the protective effects of S086 on target organs. METHODS: This study used a 14-month-old spontaneously hypertensive rat (SHR) model to evaluate the protective effects of S086 on the cardiovascular system and organs such as heart and kidney by blood pressure monitoring, urine and blood examination, pathological examination, and immunological index detection. RESULTS: After administering S086 orally to the SHR, their blood pressure and levels of renal injury indicators such as serum creatinine and urinary microalbumin were reduced, and myocardial cell necrosis and cardiac fibrosis of the heart were significantly improved. In addition, there were also significantly improvements in the histological lesions of blood vessels and the kidneys. CONCLUSIONS: The findings showed that S086 effectively reduced the blood pressure of SHR and had effects on alleviating development of heart, blood vessels and kidney.

Influence of angiotensin receptor and converting enzyme blockers therapy in the respiratory outcome of COVID-19 hospitalized patients.

OBJECTIVES: COVID-19, caused by SARS-CoV-2, has spread around the world since 2019. In severe cases, COVID-19 can lead to hospitalization and death. Systemic arterial hypertension and other comorbidities are associated with serious COVID-19 infection. Literature is unclear whether antihypertensive therapy with angiotensin receptor blockers (ARBs) and angiotensin converting enzyme (ACE) inhibitors affect COVID-19 outcomes. We aim to assess whether ACEI/ARB therapy is a risk factor for worse respiratory outcomes related to COVID-19 in hospitalized patients. METHODS: Retrospective study enrolling admitted COVID-19-diagnosed patients by RT-PCR at the Hospital Geral de Fortaleza, Brazil, during 2021. Patient medical records, sociodemographic, and clinical data were analyzed. Chest CT images were analyzed using CAD4COVID-CT/Thirona™ software. RESULTS: A total of 294 patients took part in the study. A cut-off point of 66% of pulmonary involvement was found by ROC curve, with patients having higher risk of death and intubation and lower 60-day survival. Advanced age (RR 1.025, P=0.001) and intubation (RR 16.747, P<0.001) were significantly associated with a higher risk of death. Advanced age (RR 1.023, P=0.001) and the use of noninvasive ventilation (RR 1.548, P=0.037) were associated with a higher risk of intubation. Lung involvement (>66%) increased the risk of death by almost 2.5-fold (RR 2.439, P<0.001) and by more than 2.3-fold the risk of intubation (RR 2.317, P<0.001). CONCLUSIONS: Altogether, our findings suggest that ACEI or ARB therapy does not affect the risk of death and disease course during hospitalization.

Adaptive and maladaptive roles of different angiotensin receptors in the development of cardiac hypertrophy and heart failure.

Angiotensin II (Ang II) is formed by the action of angiotensin-converting enzyme (ACE) in the renin-angiotensin system. This hormone is known to induce cardiac hypertrophy and heart failure and its actions are mediated by the interaction of both pro- and antihypertrophic Ang II receptors (AT1R and AT2R). Ang II is also metabolized by ACE 2 to Ang-(1-7), which elicits the activation of Mas receptors (MasR) for inducing antihypertrophic actions. Since heart failure under different pathophysiological situations is preceded by adaptive and maladaptive cardiac hypertrophy, we have reviewed the existing literature to gain some information regarding the roles of AT1R, AT2R, and MasR in both acute and chronic conditions of cardiac hypertrophy. It appears that the activation of AT1R may be involved in the development of adaptive and maladaptive cardiac hypertrophy as well as subsequent heart failure because both ACE inhibitors and AT1R antagonists exert beneficial effects. On the other hand, the activation of both AT2R and MasR may prevent the occurrence of maladaptive cardiac hypertrophy and delay the progression of heart failure, and thus therapy with different activators of these antihypertrophic receptors under chronic pathological stages may prove beneficial. Accordingly, it is suggested that a great deal of effort should be made to develop appropriate activators of both AT2R and MasR for the treatment of heart failure subjects.

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.

Evolving views on the first two ligands of the angiotensin II type 2 receptor. From putative antagonists to potential agonists?

The renin-angiotensin system is one of the most complex regulatory systems that controls multiple organ functions. One of its key components, angiotensin II (Ang II), stimulates two G-protein coupled class A receptors: the Ang II type 1 (AT1) receptor and the Ang II type 2 (AT2) receptor. While stimulation of the AT1 receptor causes G-protein-dependent signaling and arrestin recruitment, the AT2 receptor seems to have a constitutively active-like conformation and appears to act via G-protein-dependent and -independent pathways. Overstimulation of the AT1 receptor may lead to unwanted effects like inflammation and fibrosis. In contrast, stimulation of the AT2 receptor leads to opposite effects thus restoring the balance. However, the role of the AT2 receptor has become controversial due to beneficial effects of putative AT2 receptor antagonists. The two first synthetic AT2 receptor-selective ligands, peptide CGP42112 and small molecule PD123319, were initially both considered antagonists. CGP42112 was subsequently considered a partial agonist and it was recently demonstrated to be a full agonist. Based on the search-term PD123319 in Pubmed, 1652 studies have investigated putative AT2 receptor antagonist PD123319. Here, we put forward literature that shows beneficial effects of PD123319 alone, even at doses too low for antagonist efficacy. These beneficial effects appear compatible with agonist-like activity via the AT2 receptor. Taken together, a more consistent image of a therapeutic role of stimulated AT2 receptor emerges which may clarify current controversies.