Renal effects and associated outcomes during angiotensin-neprilysin inhibition in heart failure

Objectives: The purpose of this study was to evaluate the renal effects of sacubitril/valsartan in patients with heart failure and reduced ejection fraction. Background: Renal function is frequently impaired in patients with heart failure with reduced ejection fraction and may deteriorate further after blockade of the renin–angiotensin system. Methods: In the PARADIGM-HF (Prospective Comparison of ARNI with ACE inhibition to Determine Impact on Global Mortality and Morbidity in Heart Failure) trial, 8,399 patients with heart failure with reduced ejection fraction were randomized to treatment with sacubitril/valsartan or enalapril. The estimated glomerular filtration rate (eGFR) was available for all patients, and the urinary albumin/creatinine ratio (UACR) was available in 1872 patients, at screening, randomization, and at fixed time intervals during follow-up. We evaluated the effect of study treatment on change in eGFR and UACR, and on renal and cardiovascular outcomes, according to eGFR and UACR. Results: At screening, the eGFR was 70 ± 20 ml/min/1.73 m2 and 2,745 patients (33%) had chronic kidney disease; the median UACR was 1.0 mg/mmol (interquartile range: 0.4 to 3.2 mg/mmol) and 24% had an increased UACR. The decrease in eGFR during follow-up was less with sacubitril/valsartan compared with enalapril (−1.61 ml/min/1.73 m2/year; [95% confidence interval: −1.77 to −1.44 ml/min/1.73 m2/year] vs. −2.04 ml/min/1.73 m2/year [95% CI: −2.21 to −1.88 ml/min/1.73 m2/year ]; p < 0.001) despite a greater increase in UACR with sacubitril/valsartan than with enalapril (1.20 mg/mmol [95% CI: 1.04 to 1.36 mg/mmol] vs. 0.90 mg/mmol [95% CI: 0.77 to 1.03 mg/mmol]; p < 0.001). The effect of sacubitril/valsartan on cardiovascular death or heart failure hospitalization was not modified by eGFR, UACR (p interaction = 0.70 and 0.34, respectively), or by change in UACR (p interaction = 0.38). Conclusions: Compared with enalapril, sacubitril/valsartan led to a slower rate of decrease in the eGFR and improved cardiovascular outcomes, even in patients with chronic kidney disease, despite causing a modest increase in UACR

Effects of sacubitril/valsartan on biomarkers of extracellular matrix regulation in patients with HFrEF

Background: Myocardial fibrosis is an important pathophysiological mechanism underlying the development of heart failure (HF). Given the biochemical targets of sacubitril/valsartan, we hypothesized that circulating biomarkers reflecting the mechanisms that determine extracellular matrix (ECM) homeostasis, including collagen synthesis, processing, and degradation, are altered by sacubitril/valsartan in comparison to enalapril. Objectives: The purpose of this study was to examine the effects of sacubitril/valsartan on biomarkers of ECM homeostasis and the association between the rate of primary composite outcome (cardiovascular death or HF hospitalization) and these biomarkers. Methods: Biomarkers at baseline (n = 2,067) and both baseline and 8 months after randomization (n = 1,776) included aldosterone, soluble ST2 (sST2), tissue inhibitor of matrix metalloproteinase (TIMP)-1, matrix metalloproteinase (MMP)-2, MMP-9, Galectin-3 (Gal-3), N-terminal propeptide of collagen I (PINP), and N-terminal propeptide of collagen III (PIIINP). The effects of sacubitril/valsartan on biomarkers were compared with enalapril. Baseline biomarker values and changes from baseline to 8 months were related to primary outcome. Results: At baseline, the profibrotic biomarkers aldosterone, sST2, TIMP-1, Gal-3, PINP, and PIIINP were higher, and biomarkers associated with collagen degradation, MMP-2 and -9, were lower than published referent control values. Eight months after randomization, aldosterone, sST2, TIMP-1, MMP-9, PINP, and PIIINP had decreased more in the sacubitril/valsartan than enalapril group. At baseline, higher values of sST-2, TIMP-1, and PIIINP were associated with higher primary outcome rates. Changes from baseline to 8 months in sST-2 and TIMP-1 were associated with change in outcomes. Conclusions: Biomarkers associated with profibrotic signaling are altered in HF with reduced ejection fraction, sacubitril/valsartan significantly decreased many of these biomarkers, and these biomarkers have important prognostic value. These findings suggest that sacubitril/valsartan may reduce profibrotic signaling, which may contribute to the improved outcomes. (This Study Will Evaluate the Efficacy and Safety of LCZ696 Compared to Enalapril on Morbidity and Mortality of Patients With Chronic Heart Failure [PARADIGM-HF]; NCT01035255

Prognostic implications of congestion on physical examination among contemporary patients with heart failure and reduced ejection fraction: PARADIGM-HF

Background: The contemporary prognostic value of the physical examination— beyond traditional risk factors including natriuretic peptides, risk scores, and symptoms—in heart failure (HF) with reduced ejection fraction is unknown. We aimed to determine the association between physical signs of congestion at baseline and during study follow-up with quality of life and clinical outcomes and to assess the treatment effects of sacubitril/valsartan on congestion. Methods: We analyzed participants from PARADIGM-HF (Prospective Comparison of Angiotensin Receptor-Neprilysin Inhibitor With Angiotensin Converting Enzyme Inhibitor to Determine Impact on Global Mortality and Morbidity in HF) with an available physical examination at baseline. We examined the association of the number of signs of congestion (jugular venous distention, edema, rales, and third heart sound) with the primary outcome (cardiovascular death or HF hospitalization), its individual components, and all-cause mortality using time-updated, multivariable-adjusted Cox regression. We further evaluated whether sacubitril/valsartan reduced congestion during follow-up and whether improvement in congestion is related to changes in clinical outcomes and quality of life, assessed by Kansas City Cardiomyopathy Questionnaire overall summary scores. Results: Among 8380 participants, 0, 1, 2, and 3+ signs of congestion were present in 70%, 21%, 7%, and 2% of patients, respectively. Patients with baseline congestion were older, more often female, had higher MAGGIC risk scores (Meta-Analysis Global Group in Chronic Heart Failure) and lower Kansas City Cardiomyopathy Questionnaire overall summary scores (P<0.05). After adjusting for baseline natriuretic peptides, time-updated Meta-Analysis Global Group in Chronic Heart Failure score, and time-updated New York Heart Association class, increasing time-updated congestion was associated with all outcomes (P<0.001). Sacubitril/valsartan reduced the risk of the primary outcome irrespective of clinical signs of congestion at baseline (P=0.16 for interaction), and treatment with the drug improved congestion to a greater extent than did enalapril (P=0.011). Each 1-sign reduction was independently associated with a 5.1 (95% CI, 4.7–5.5) point improvement in Kansas City Cardiomyopathy Questionnaire overall summary scores. Change in congestion strongly predicted outcomes even after adjusting for baseline congestion (P<0.001). Conclusions: In HF with reduced ejection fraction, the physical exam continues to provide significant independent prognostic value even beyond symptoms, natriuretic peptides, and Meta-Analysis Global Group in Chronic Heart Failure risk score. Sacubitril/valsartan improved congestion to a greater extent than did enalapril. Reducing congestion in the outpatient setting is independently associated with improved quality of life and reduced cardiovascular events, including mortality

Conformation Guides Molecular Efficacy in Docking Screens of Activated β-2 Adrenergic G Protein Coupled Receptor

A prospective, large library virtual screen against an activated β2-adrenergic receptor (β2AR) structure returned potent agonists to the exclusion of inverse-agonists, providing the first complement to the previous virtual screening campaigns against inverse-agonist-bound G protein coupled receptor (GPCR) structures, which predicted only inverse-agonists. In addition, two hits recapitulated the signaling profile of the co-crystal ligand with respect to the G protein and arrestin mediated signaling. This functional fidelity has important implications in drug design, as the ability to predict ligands with predefined signaling properties is highly desirable. However, the agonist-bound state provides an uncertain template for modeling the activated conformation of other GPCRs, as a dopamine D2 receptor (DRD2) activated model templated on the activated β2AR structure returned few hits of only marginal potency

Effects of sacubitril/valsartan on N-terminal pro-B-type natriuretic peptide in heart failure with preserved ejection fraction

Objectives: The authors sought to evaluate the prognostic significance of baseline N-terminal pro–B-type natriuretic peptide (NT-proBNP), whether NT-proBNP modified the treatment response to sacubitril/valsartan, and the treatment effect of sacubitril/valsartan on NT-proBNP overall and in key subgroups. Background: Sacubitril/valsartan reduces NT-proBNP in heart failure (HF) with both reduced and preserved ejection fraction (EF), but did not significantly reduce total HF hospitalizations and cardiovascular death compared with valsartan in patients with HF with preserved EF (HFpEF). Methods: In the PARAGON-HF (Efficacy and Safety of LCZ696 Compared to Valsartan, on Morbidity and Mortality in Heart Failure Patients With Preserved Ejection Fraction) trial, 4,796 patients with HFpEF and elevated NT-proBNP were randomized to sacubitril/valsartan or valsartan. NT-proBNP was measured at screening in all patients and at 5 subsequent times in >2,700 patients: before, between, and after sequential valsartan and sacubitril/valsartan run-in periods, and 16 and 48 weeks post-randomization. Results: Median NT-proBNP was 911 pg/ml (interquartile range: 464 to 1,613 pg/ml) at screening. Screening NT-proBNP was strongly associated with the primary endpoint, total HF hospitalizations and cardiovascular death (rate ratio [RR]: 1.68 per log increase in NT-proBNP, 95% confidence interval [CI]: 1.53 to 1.85; p < 0.001). This relationship was stronger in patients with atrial fibrillation (adjusted RR: 2.33 [95% CI: 1.89 to 2.87] vs. 1.58 [95% CI: 1.42 to 1.75] in patients without atrial fibrillation; p interaction <0.001) and weaker in obese patients (adjusted RR: 1.50 [95% CI: 1.31 to 1.71] vs. 1.92 [95% CI: 1.70 to 2.17] in nonobese patients; p interaction <0.001). Screening NT-proBNP did not modify the treatment effect of sacubitril/valsartan compared with valsartan (p interaction = 0.96). Sacubitril/valsartan reduced NT-proBNP by 19% (95% CI: 14% to 23%; p < 0.001) compared with valsartan 16 weeks post-randomization, with similar reductions in men (20%) and women (18%), and in patients with left ventricular EF ≤57% (20%) and >57% (18%). Decreases in NT-proBNP predicted lower subsequent risk of the primary endpoint. Conclusions: Baseline NT-proBNP predicted HF events but did not modify the sacubitril/valsartan treatment effect in patients with HFpEF. Sacubitril/valsartan reduced NT-proBNP consistently in men and women, and in patients with lower or higher EF. (Efficacy and Safety of LCZ696 Compared to Valsartan, on Morbidity and Mortality in Heart Failure Patients With Preserved Ejection Fraction [PARAGON-HF]; NCT01920711

Angiotensin-Neprilysin Inhibition in Heart Failure with Preserved Ejection Fraction

Background The angiotensin receptor-neprilysin inhibitor sacubitril-valsartan led to a reduced risk of hospitalization for heart failure or death from cardiovascular causes among patients with heart failure and reduced ejection fraction. The effect of angiotensin receptor-neprilysin inhibition in patients with heart failure with preserved ejection fraction is unclear. Methods We randomly assigned 4822 patients with New York Heart Association (NYHA) class II to IV heart failure, ejection fraction of 45% or higher, elevated level of natriuretic peptides, and structural heart disease to receive sacubitril-valsartan (target dose, 97 mg of sacubitril with 103 mg of valsartan twice daily) or valsartan (target dose, 160 mg twice daily). The primary outcome was a composite of total hospitalizations for heart failure and death from cardiovascular causes. Primary outcome components, secondary outcomes (including NYHA class change, worsening renal function, and change in Kansas City Cardiomyopathy Questionnaire [KCCQ] clinical summary score [scale, 0 to 100, with higher scores indicating fewer symptoms and physical limitations]), and safety were also assessed. Results There were 894 primary events in 526 patients in the sacubitril-valsartan group and 1009 primary events in 557 patients in the valsartan group (rate ratio, 0.87; 95% confidence interval [CI], 0.75 to 1.01; P=0.06). The incidence of death from cardiovascular causes was 8.5% in the sacubitril-valsartan group and 8.9% in the valsartan group (hazard ratio, 0.95; 95% CI, 0.79 to 1.16); there were 690 and 797 total hospitalizations for heart failure, respectively (rate ratio, 0.85; 95% CI, 0.72 to 1.00). NYHA class improved in 15.0% of the patients in the sacubitril-valsartan group and in 12.6% of those in the valsartan group (odds ratio, 1.45; 95% CI, 1.13 to 1.86); renal function worsened in 1.4% and 2.7%, respectively (hazard ratio, 0.50; 95% CI, 0.33 to 0.77). The mean change in the KCCQ clinical summary score at 8 months was 1.0 point (95% CI, 0.0 to 2.1) higher in the sacubitril-valsartan group. Patients in the sacubitril-valsartan group had a higher incidence of hypotension and angioedema and a lower incidence of hyperkalemia. Among 12 prespecified subgroups, there was suggestion of heterogeneity with possible benefit with sacubitril-valsartan in patients with lower ejection fraction and in women. Conclusions Sacubitril-valsartan did not result in a significantly lower rate of total hospitalizations for heart failure and death from cardiovascular causes among patients with heart failure and an ejection fraction of 45% or higher. (Funded by Novartis; PARAGON-HF ClinicalTrials.gov number, NCT01920711.

Novel Bradykinin Analogues Modified in the N-Terminal Part of the Molecule with a Variety of Acyl Substituents

In the current work we present some pharmacological characteristics of ten new analogues of bradykinin (Arg–Pro–Pro–Gly–Phe–Ser–Pro–Phe–Arg) modified in the N-terminal part of the molecule with a variety of acyl substituents. Of the many acylating agents used previously with B2 receptor antagonists, the following residues were chosen: 1-adamantaneacetic acid (Aaa), 1-adamantanecarboxylic acid (Aca), 4-tert-butylbenzoic acid (t-Bba), 4-aminobenzoic acid (Aba), 12-aminododecanoic acid (Adc), succinic acid (Sua), 4-hydroxybenzoic acid, 4-hydroxy-3-methoxybenzoic acid, 3-(4-hydroxyphenyl)propionic acid and 6-hydroxy-2-naphthoic acid. Biological activity of the compounds was assessed in the in vivo rat blood pressure test and the in vitro rat uterus test. Surprisingly, N-terminal substitution of the bradykinin peptide chain itself with aforementioned groups resulted in antagonists of bradykinin in the pressor test and suppressed agonistic potency in the uterotonic test. These interesting findings need further studies as they can be helpful for designing more potent B2 receptor blockers

Prevalent and incident anemia in PARADIGM-HF and the effect of sacubitril/valsartan

Background: Anemia is common in patients with heart failure with reduced ejection fraction and is associated with poor clinical outcomes. Renin-angiotensin system blockers lower hemoglobin and may induce anemia. Objectives: The authors investigated whether concomitant neprilysin inhibition might ameliorate this effect of renin-angiotensin system blockers in PARADIGM-HF (Prospective comparison of ARNI with ACEI to Determine Impact on Global Mortality and morbidity in Heart Failure). Methods: Anemia was defined as hemoglobin <120 g/L in women and <130 g/L in men at screening. The authors investigated the effect of randomized treatment on clinical outcomes according to anemia status, change in hemoglobin from baseline, and the incidence of anemia. Results: Of 8,239 participants with a baseline hemoglobin measurement, 1,677 (20.4%) were anemic. Patients with anemia had a more severe heart failure profile, worse kidney function, greater neurohormonal derangement, and worse clinical outcomes. Sacubitril/valsartan, compared with enalapril, decreased the risk of cardiovascular death or heart failure hospitalization similarly in patients with (HR: 0.84; 95% CI: 0.71-1.00) and without anemia (HR: 0.78 [95% CI: 0.71-0.87]; P value for interaction = 0.478). Between baseline and 12 months, hemoglobin decreased by 1.5 g/L (95% CI: 1.2-1.7 g/L) with sacubitril/valsartan compared with 2.3 g/L (95% CI: 2.0-2.6 g/L) with enalapril: mean difference 0.8 g/L (95% CI: 0.5-1.2 g/L; P < 0.001). Patients assigned to sacubitril/valsartan were less likely to develop anemia at 12 months (321 of 2,806 [11.4%]) compared with patients randomized to enalapril (440 of 2,824 [15.6%]) (odds ratio [OR]: 0.70 [95% CI: 0.60-0.81]; P < 0.001). These findings were similar in PARAGON-HF (Prospective Comparison of ARNI with ARB Global Outcomes in HF with Preserved Ejection Fraction) (sacubitril/valsartan vs valsartan). There was biomarker evidence of increased iron utilization with sacubitril/valsartan. Conclusions: Irrespective of anemia status, sacubitril/valsartan compared with enalapril, decreased mortality and hospitalization. Hemoglobin decreased less with sacubitril/valsartan and the incidence of new anemia was lower with sacubitril/valsartan. (This study will evaluate the Prospective comparison of ARNI with ACEI to Determine Impact on Global Mortality and morbidity in Heart Failure [PARADIGM-HF] trial; NCT01035255)

Comparative Analysis of the Heptahelical Transmembrane Bundles of G Protein-Coupled Receptors

Background: G protein-coupled receptors represent a large family of eukaryotic membrane proteins, and are involved in almost all physiological processes in humans. Recent advances in the crystallographic study of these receptors enable a detailed comparative analysis of the commonly shared heptahelical transmembrane bundle. Systematic comparison of the bundles from a variety of receptors is indispensable for understanding not only of the structural diversification optimized for the binding of respective ligands but also of the structural conservation required for the common mechanism of activation accompanying the interaction changes among the seven helices. Methodology/Principal Findings: We have examined the bundles of 94 polypeptide chains from almost all available structures of 11 receptors, which we classified into either inactivated chain or activated chain, based on the type of bound ligand. For the inactivated chains, superposition of 200 residue bundles by secondary structure matching demonstrated that the bound ligands share a laterally limited cavity in the extracellular section of the bundle. Furthermore, a distinct feature was found for helix III of bovine rhodopsin, which might have evolved to lower its activity in the presence of 11-cis-retinal, to a level that other receptors could hardly achieve with any currently available ligands. Conclusions/Significance: Systematic analysis described here would be valuable for understanding of the rearrangement o