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The authors investigated the antihypertensive effect of sacubitril/valsartan (Sac/Val) when switching from other drugs and assessed whether brain natriuretic peptide (BNP) or plasma renin activity (PRA) before drug switching was a predictor of blood pressure lowering after switching to Sac/Val. In 92 patients with treated hypertension, clinic blood pressure, plasma BNP, and PRA were examined before and after switching to Sac/Val. Clinic systolic and diastolic blood pressures significantly decreased after drug switching to Sac/Val (p < .0001, respectively). The level before drug switching of BNP had no correlation with the change in systolic blood pressure (Δ-SBP) before and after switching to Sac/Val, but that of PRA was significantly correlated with Δ-SBP (r = .3807, p = .0002). A multiple regression analysis revealed that PRA before drug switching was an independent determinant of Δ-SBP. Our findings suggest that low PRA may become a useful marker to predict the antihypertensive effect of switching to Sac/Val in treated hypertensive patients., (© 2024 The Author(s). The Journal of Clinical Hypertension published by Wiley Periodicals LLC.)

Background: In many practices, the screening for primary aldosteronism relies on a single-blood draw for plasma aldosterone concentration (PAC) and plasma renin activity (PRA) to establish an aldosterone-to-renin ratio (ARR). ARR levels vary between expert centers and repeated assays in the same individual, emphasizing the potential variability of this screening approach. A suppressed PRA to <1 ng/mL per h has been proposed as an alternative test to the ARR., Methods: We compared 2 potential screening approaches to identify probable primary aldosteronism (ARR≥30 or ARR≥20 versus PRA suppressed below 1 ng/mL per h) in a cohort of 94 829 paired PRA and PAC samples submitted by clinicians to evaluate the presence of primary aldosteronism., Results: Of 94 829 patients, 20.3% tested positive based on ARR≥20 (95% CI, 20.0%-20.5%), 13.9% based on ARR≥30 (95% CI, 13.6%-14.1%), versus 45.9% based on suppressed PRA (<1 ng/mL per minute [95% CI, 45.5%-46.2%]). In the PRA group, a range of aldosterone levels was observed: 5.5% had PAC >15 ng/dL, 25.2% had PAC 5 to 15 ng/dL, and 15.2% had PAC <5 ng/dL, compared with 6%, 12.7%, and 1.6% in the ARR≥20 group and 4.7%, 8.5%, and 0.7% in the ARR≥30 group., Conclusions: In this cohort of individuals being screened for primary aldosteronism, substantially more individuals were identified using criteria focused on suppression of renin activity compared with using the aldosterone renin ratio as a screening tool., Competing Interests: M. Marcelli, C. Bi, and M.J. McPhaul are employed by Quest Diagnostics.

Primary aldosteronism (PA) is the most common cause of endocrine arterial hypertension, and the suggested screening test for case detection is the aldosterone-to-renin ratio (ARR) or aldosterone-to-direct renin ratio (ADRR) based on radio-immunoassay (RIA) and chemiluminescence assay (CLIA), respectively. The objective of our study was to evaluate the reliability of CLIA for aldosterone and renin measurement and the diagnostic performance of ADRR. A prospective cohort of 1110 patients referred to a single laboratory medicine center underwent measurement of aldosterone and direct renin concentration (DRC) by CLIA and measurement of aldosterone and plasma renin activity (PRA) by RIA. Of 1110 patients, 640 obtained a final diagnosis of hypertension, and 90 of these patients were diagnosed with PA. Overall, between-method correlation was highly significant for aldosterone concentrations ( R = 0.945, p < 0.001) and less strong but significant for DRC/PRA ( R = 0.422, p < 0.001). Among hypertensive patients, in PA cases, the areas under the receiver operator characteristics (ROC) curves were 0.928 (95% confidence interval 0.904-0.954) for ADRR and 0.943 (95% confidence interval 0.920-0.966) for ARR and were comparable and not significantly different. The highest accuracy was obtained with an ADRR cut-off of 25 (ng/L)/(mIU/L), displaying a sensitivity of 91% and a specificity of 85%. The chemiluminescence assay for aldosterone and DRC is a reliable method for PA diagnosis compared to the classical RIA method.

Introduction: Low-renin hypertension (LRH) accounts for approximately one-third of patients with hypertension and are more prevalent in women and the older adult population. Previous study has found a link between the renin-angiotensin-aldosterone system (RAAS) and sex hormones. However, there are insufficient data on the relationship between LRH and metabolic or musculoskeletal outcomes in older adults., Methods and Materials: Among the 343 participants from a population-based cohort study conducted between May 2018 and August 2019, a total of 256 (86 men older than 50 years and 170 postmenopausal women) were included. The presence of LRH was defined as plasma renin activity (PRA) <1 ng/mL/h and systolic blood pressure (BP) ≥130 or diastolic BP ≥80 mmHg based on the 2017 ACC/AHA guidelines. Individuals with missing data, and those who had used medications that could affect PRA within the past six months were excluded. Bone mineral density (BMD), trabecular bone score (TBS), and appendicular lean mass (ALM) index were assessed using dual-energy X-ray absorptiometry; degraded TBS was defined as partially degraded to degraded levels (≤1.350). Muscle function was assessed according to the Asian Working Group for Sarcopenia guidelines. PRA was measured using radioimmunoassay., Results: The median age was 66 [61-72] years, and the body mass index (BMI) was 24.7 [23.0-26.4] kg/m 2 . Individuals with LRH, accounting for 34.8%, had lower diabetes mellitus; more dyslipidemia; and poorer muscle function, BMD, and TBS than those in the non-LRH group. In addition, PRA was positively correlated with C-peptide, HOMA-IR, TBS, and ALM index. After adjusting for covariates including age and BMI, LRH was negatively associated with femur neck T-score (adjusted β = -0.30, 95% CI [-0.55 to -0.05], p  = 0.021) and the presence of LRH was significantly associated with degraded TBS in women (adjusted odds ratio = 3.00, 95% CI [1.36-6.58], p  = 0.006)., Conclusion: Our findings suggest that LRH can influence clinical features and metabolic risk in older adults. Notably, LRH in postmenopausal women was linked to lower femur neck T-scores and degraded TBS, indicating sex-specific effects of LRH on bone health. Larger prospective studies are required to elucidate how changes in the RAAS affect metabolic and musculoskeletal outcomes in older adults., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Lee, Chang, Park, Koh, Kim and Lim.)

Introduction: Heart failure (HF) progression according to changes in the serum chloride concentration ([sCl-]) was recently proposed as the "chloride (Cl) theory" for HF pathophysiology. The present study examined the association of neurohormones and renal Cl avidity to determine their contribution to acute HF and their involvement to the "Cl theory.", Methods: Data from 29 patients with acute HF (48% men; 80.3 ± 12 years) were analyzed. Blood and urine samples were obtained before decongestive therapy. Clinical tests included peripheral blood, serum and spot urinary electrolytes, b-type natriuretic peptide (BNP), and plasma neurohormones., Results: In the 29 patients, urinary Cl concentrations ([uCl-]) inversely correlated with log (plasma renin activity [PRA]) (r = -0.64, p = 0.0002) and log (plasma aldosterone concentration) (r = -0.50, p = 0.006). The [sCl-]‒[uCl-] difference positively correlated with log PRA (r = 0.63, p = 0.0002) and log (plasma aldosterone concentration) (r = 0.49, p = 0.008). Patients were divided into 2 groups according to the [sCl-]‒[uCl-] difference, an excretion (low renal Cl avidity) group and an absorption (high renal Cl avidity) group. Compared with the excretion group (-77 to ‒5 mEq/L; n = 14), the absorption group (1-84 mEq/L; n = 15) exhibited greater renal impairment (serum creatinine; 1.45 ± 0.63 vs. 1.00 ± 0.38 mg/d, p = 0.029) and cardiac burden (log BNP; 2.99 ± 0.3 vs. 2.66 ± 0.32 pg/mL, p = 0.008), higher log PRA (0.20 ± 0.58 vs. -0.25 ± 0.35 ng/mL/h, p = 0.018), and lower fractional urinary Cl excretion (1.34 ± 1.3 vs. 5.33 ± 4.1%, p &lt; 0.001)., Conclusion: Renal Cl avidity differs in acute HF, i.e., excretion (low renal Cl avidity) versus absorption (high renal Cl avidity) types, involving renin-aldosterone-angiotensin activity as the underlying mechanism, which provides the neurohormonal background for the "Cl theory." A version of this study was presented in part at the annual international scientific assembly (ACC.23) of the American College of Cardiology, March 4-6, 2023., (© 2024 The Author(s). Published by S. Karger AG, Basel.)

Since the 1970s, when the initial reports of neonatal hypertension related to renal artery thromboembolism were published, other secondary causes of neonatal hypertension have been reported. Those infants with no identifiable cause of hypertension were labeled with a variety of terms. Herein, we describe such infants as having idiopathic neonatal hypertension (INH). Most, but not all, of these hypertensive infants were noted to have bronchopulmonary dysplasia (BPD). More recently, reports described common clinical characteristics seen in INH patients, whether or not they had BPD. This phenotype includes low plasma renin activity, presentation near 40 weeks postmenstrual age, and a favorable response to treatment with spironolactone. A small prospective study in INH patents showed evidence of mineralocorticoid receptor activation due to inhibition of 11β-HSD2, the enzyme that converts cortisol to the less potent mineralocorticoid-cortisone. Meanwhile, phthalate metabolites have been shown to inhibit 11β-HSD2 in human microsomes. Premature infants can come in contact with exceptionally large phthalate exposures, especially those infants with BPD. This work describes a common low-renin phenotype, commonly seen in patients categorized as having INH. Further, we review the evidence that hypertension in INH patients with the low-renin phenotype may be mediated by phthalate-associated inhibition of 11β-HSD2. Lastly, we review the implications of these findings regarding identification, treatment, and prevention of the low-renin hypertension phenotype seen in premature infants categorized as having INH., (© 2022. The Author(s), under exclusive licence to International Pediatric Nephrology Association.)

Despite extensive studies on blood pressure, its genetic risk factors remain uncertain. Even one of the most researched blood pressure-related traits - renin - is not fully understood genetically. Here, we determine the genetic relationship and associated predisposition between blood pressure and baseline renin. In 8840 Korean individuals, we observed a strong negative genome-wide genetic correlation (r g  = -0.484) between systolic blood pressure (SBP) and plasma renin activity (PRA), suggesting that antagonistic genetic signals explain the variance in the two traits. We found 51 significant pleiotropic SNPs affecting the two traits, which could contribute to the Renin-Angiotensin-Aldosterone System (RAAS). Our findings provide insight into studies on RAAS by identifying the genome-wide relationship and susceptibility loci of SBP and PRA., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest., (Copyright © 2022. Published by Elsevier Inc.)

Accurate determination of plasma renin activity (PRA) is essential for the development and maintenance of an effective screening program for primary aldosteronism (PA). PRA measurement can also be useful in the investigation of renal artery stenosis, syndrome of mineralocorticoid excess, Addison's disease, congenital adrenal hyperplasia, Bartters and Gitelman syndromes, and for inherited defects in the renin angiotensin aldosterone system (RAAS). We describe a semiautomated and simple method for the accurate and precise measurement of PRA from 500 μL of plasma (250 μL if blank subtraction is omitted, as discussed) using a liquid chromatography and tandem mass spectrometry (LC-MS/MS) method for angiotensin I (AngI) in 96-well format. After a 3 h AngI generation step at 37 °C in buffering conditions at pH 6, the reaction is quenched with 10% formic acid containing AngI internal standard. Sample preparation then proceeds with offline solid phase extraction, two wash steps, and methanol elution followed by injection into the LC-MS/MS system. Quantitation is performed against a 7-point calibration linear curve prepared in buffer. The assay calibration range is 0.34-30.0 ng/mL, which corresponds to PRA values of 0.11-10.0 ng/mL/h: much wider than was possible using traditional competitive antibody-based methods. Total precision in clinical production has been observed to be 5.8-5.0% for BioRad Hypertension Control materials having nominal PRA values ranging from 1.73 to 12.43 ng/mL/h. At AngI concentrations of 0.06 ng/L (corresponding to a PRA of 0.02 ng/mL/h), signal-to-noise ratio is 50:1, indicating that the limit of quantitation is well below the level required for clinical use., (© 2022. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: The renin-angiotensin-aldosterone system plays a key role in blood pressure (BP) regulation and is the target of several antihypertensive medications. Renal denervation (RDN) is thought to interrupt the sympathetic-mediated neurohormonal pathway as part of its mechanism of action to reduce BP., Objectives: The purpose of this study was to evaluate plasma renin activity (PRA) and aldosterone before and after RDN and to assess whether these baseline neuroendocrine markers predict response to RDN., Methods: Analyses were conducted in patients with confirmed absence of antihypertensive medication. Aldosterone and PRA levels were compared at baseline and 3 months post-procedure for RDN and sham control groups. Patients in the SPYRAL HTN-OFF MED Pivotal trial were separated into 2 groups, those with baseline PRA ≥0.65 ng/ml/h (n = 110) versus <0.65 ng/ml/h (n = 116). Follow-up treatment differences between RDN and sham control groups were adjusted for baseline values using multivariable linear regression models., Results: Baseline PRA was similar between RDN and control groups (1.0 ± 1.1 ng/ml/h vs. 1.1 ± 1.1 ng/ml/h; p = 0.37). Change in PRA at 3 months from baseline was significantly greater for RDN compared with control subjects (-0.2 ± 1.0 ng/ml/h; p = 0.019 vs. 0.1 ± 0.9 ng/ml/h; p = 0.14), p = 0.001 for RDN versus control subjects, and similar differences were seen for aldosterone: RDN compared with control subjects (-1.2 ± 6.4 ng/dl; p = 0.04 vs. 0.4 ± 5.4 ng/dl; p = 0.40), p = 0.011. Treatment differences at 3 months in 24-h and office systolic blood pressure (SBP) for RDN versus control patients were significantly greater for patients with baseline PRA ≥0.65 ng/ml/h versus <0.65 ng/ml/h, despite similar baseline BP. Differences in office SBP changes according to baseline PRA were also observed earlier at 2 weeks post-RDN., Conclusions: Plasma renin activity and aldosterone levels for RDN patients were significantly reduced at 3 months when compared with baseline as well as when compared with sham control. Higher baseline PRA levels were associated with a significantly greater reduction in office and 24-h SBP. (SPYRAL PIVOTAL - SPYRAL HTN-OFF MED Study; NCT02439749)., Competing Interests: Funding Support and Author Disclosures The SPYRAL HTN-OFF MED Pivotal trial was sponsored by Medtronic. Profs. Mahfoud and Böhm are supported by Deutsche Forschungsgemeinschaft (SFB TRR219). Prof. Mahfoud is supported by Deutsche Gesellschaft für Kardiologie; and has received scientific support and speaker honoraria from Bayer, Boehringer Ingelheim, Medtronic, and ReCor Medical. Prof. Townsend has received consultant fees from Medtronic, Axio, and Regeneron. Dr. Kandzari has received institutional research/grant support from Medtronic CardioVascular and Ablative Solutions; and has received personal consulting honoraria from Medtronic CardioVascular. Prof. Kario has received scientific support and speaker honoraria from Daichi-Sankyo, Sanwa Chemical, Boehringer Ingelheim, Omron Healthcare, A&D Inc., Fukudadenshi Inc., Medtronic, and ReCor Medical. Prof. Schmieder has received consultant fees from Medtronic and Recor; and has received grant support from Medtronic, Recor, and Ablative Solutions. Dr. Tsioufis has received honoraria for advisory boards and lectures from Medtronic, Servier, Bayer, Menarini, Novartis, AstraZeneca, Boehringer Inc., Pfizer, Pythagoras, Sanofi, and Amgen. Dr. Pocock has received consultant fees from Medtronic. Dr. Walton has served as a proctor for Medtronic and Abbott; has served on the medical advisory board for Medtronic; and has received grant support from Medtronic, Abbott, and Edwards. Prof. T. Weber has received scientific support from I.E.M. GmbH. Dr. Cohen and Mr. Fahy are employees and shareholders for Medtronic. Prof. Böhm has received consulting fees from Abbott Vascular, Bayer AG, Amgen, AstraZeneca, Servier, Medtronic, Vifor, and Boehringer Ingelheim. Prof. M. Weber has received consulting fees from Medtronic, ReCor, and Ablative Solutions. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Aims: Plasma renin activity (PRA) is regarded as a marker of sodium and fluid homeostasis in patients with primary hypertension. Whether effects of diuretics on PRA differ according to class of diuretic, whether diuretics lead to a sustained increase in PRA, and whether changes in PRA relate to those in blood pressure (BP) is unknown. We performed a systematic review and meta-analysis of trials investigating the antihypertensive effects of diuretic therapy in which PRA and/or other biomarkers of fluid homeostasis were measured before and after treatment., Methods: Three databases were searched: MEDLINE, EMBASE and The Cochrane Central Register of Controlled Trials. Titles were firstly screened by title and abstract for relevancy before full-text articles were assessed for eligibility according to a predefined inclusion/exclusion criteria., Results: A total of 1684 articles were retrieved of which 61 met the prespecified inclusion/exclusion criteria. PRA was measured in 30/61 studies. Diuretics led to a sustained increase in PRA which was similar for different classes of diuretic (standardised mean difference [95% confidence interval] 0.481 [0.362, 0.601], 0.729 [0.181, 1.28], 0.541 [0.253, 0.830] and 0.548 [0.159, 0.937] for thiazide, loop, mineralocorticoid receptor antagonists/potassium-sparing and combination diuretics respectively, Q = 0.897, P = .826), and did not relate to the average decrease in blood pressure., Conclusion: In antihypertensive drug trials, diuretics lead to a sustained increase in average PRA, which is similar across different classes of diuretic and unrelated to the average reduction in blood pressure., (© 2020 The Authors. British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.)

Background: Plasma renin activity (PRA) has been related to all-cause mortality and cardiovascular events in patients with cardiovascular disease. However, data from patients with acute coronary syndromes (ACS) are sparse., Methods: Determination of PRA was made in 550 patients with ACS, including a subgroup of 287 patients not on treatment with angiotensin converting enzyme inhibitors, angiotensin receptor blockers or diuretics, and without heart failure. We evaluated the relations between PRA and all-cause mortality after three years and long-term, and to cardiovascular events after median 8.7 years. Adjustments were made for variables that influenced the hazard ratio (HR) > 5% for the relation between PRA and outcome., Results: Baseline PRA was associated with all-cause mortality during three-years (unadjusted HR 1.74 per 1 SD increase in logarithmically transformed PRA; 95% confidence interval (CI) 1.39-2.16, p < 0.0001) and long-term (HR 1.12, CI 1.00-1.25, p = 0.046). After adjustments, only the three-year association remained significant. In unadjusted analyses, PRA was associated with cardiovascular death, but not with nonfatal cardiovascular events. In the subgroup there was an inverse relation between PRA and long-term all-cause mortality., Conclusion: Higher PRA was a significant independent predictor of all-cause mortality after three years, but not at long-term follow-up and not significantly associated with cardiovascular incidence. The renin-angiotensin-system pathophysiology is of great interest, not least due to its association with the COVID-19 pandemic. Our findings indicate a need for further research on the prognostic/predictive aspects of the renin-angiotensin-system in ACS., Competing Interests: Declaration of Competing Interest None., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)

Sodium-glucose cotransporter-2 inhibitors (SGLT2Is) are reported to prevent cardiovascular events by a mechanism possibly including diuresis and sodium excretion. In this respect, diuresis-induced compensatory upregulation of the renin-angiotensin-aldosterone (RAA) system should be clarified and we performed a randomized controlled trial using dapagliflozin, an SGLT2I. Hypertensive diabetic patients taking angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers were randomly assigned to a dapagliflozin group (DAPA) or a control group (CTRL) with the difference in the changes in plasma renin activity (PRA) after 24 weeks of the treatment as the primary outcome. PRA, plasma aldosterone concentration (PAC), age, sex, BMI, blood pressure, pulse rate, eGFRcys, and HbA1c were not different between the groups at baseline. After 24 weeks, the changes in the PRA from the baseline of the DAPA (n = 44) and CTRL (n = 39) groups were 6.30 ± 15.55 and 1.42 ± 11.43 ng/mL/h, respectively (p = 0.11) although the power of detection was too small. However, post hoc nonparametric analyses revealed that there was a definite increase in the PRA and PAC in the DAPA group (p < 0.0001 and p = 0.00025, respectively) but not in the CTRL group. The PRA in the DAPA group after 24 weeks treatment was significantly elevated compared to the CTRL group (p = 0.013) but not for the PAC. Accordingly, it would be suggested that dapagliflozin may not induce a profound increase, if any, in PAC after 24 weeks of treatment in hypertensive type 2 diabetic patients under RAA suppression.

Background: To study the genetic forms and pathophysiology of arterial hypertension by evaluating plasma renin activity in the Shors, minor indigenous peoples inhabiting the south of Western Siberia., Methods: A single-stage study of indigenous (the Shors) and non-indigenous peoples living in the villages of Gornaya Shoria of the Kemerovo region in the south of Western Siberia was conducted in the period from 2013 to 2017. One thousand four hundred nine adults (901 Shors and 508 non-indigenous inhabitants) were recruited in the study using a continuous sampling plan. Arterial blood pressure was measured according to 2018 ESC/ESH guidelines for the management of arterial hypertension. All the respondents underwent clinical and instrumental examination. Plasma renin activity was determined by enzyme-linked immunoassay with the BRG kits (Germany). Polymorphisms of ACE (I/D, rs 4340), АGT (c.803 T > C, rs699), AGTR1 (А1166С, rs5186), ADRB1 (с.145A > G, Ser49Gly, rs1801252) and ADRA2B (I/D, rs 28,365,031) genes were tested using polymerase chain reaction., Results: Renin-dependent hypertensive patients prevailed in both ethnic groups (65.6% in the indigenous group vs. 89.8% in the non-indigenous group, p = 0.001). Prevalence of a volume-dependent AH was low in both groups (34.4% in the indigenous group vs. 10.2% in the non-indigenous group, р = 0.001). The D/D and Т/Т genotypes of the АСЕ [OR = 6.97; 95% CI (1.07-55.58)] and AGT [OR = 3.53; 95% CI (1.02-12.91)] genes were associated with the renin-dependent AH in the Shors. The C/C genotype of AGTR1 gene was found to predispose to the volume-dependent AH [OR = 5.25; 95% CI (1.03-27.89)]. The C/C genotype of AGTR1 gene was associated with moderate or high renin levels suggesting essential AH in the non-indigenous group [OR = 5.00; 95% CI (1.21-22.30), р = 0.029]., Conclusion: An in-depth understanding of AH pathophysiology and its genetic forms ensures the optimal choice of blood pressure-lowering treatment and optimizes AH control.

While the role of plasma renin activity (PRA) in heart failure has been widely studied in adults, comprehensive data on pediatric heart failure remain lacking. This drawback is increasingly being addressed by academic research. Nevertheless, such pediatric investigations are commonly conducted only once due to ethical constraints. Therefore, the quality of bioanalytical data must be ensured to acquire meaningful insights into maturing humoral parameters. However, appropriate post-validation assessment of bioanalytical runs is currently underrepresented by regulatory guidance. Thus, for applications in an academic environment, an easy-to-handle six-step bioanalytical quality control system was designed based on regulatory guidelines (e.g. U.S. Food and Drug Administration) combined with international recommendations (e.g. Clinical and Laboratory Standards Institute) and current scientific discussion. Its applicability to an enzyme-linked immunosorbent assay for determination of PRA was investigated within three pediatric trials of the EU-funded "Labeling of Enalapril in Neonates up to Adolescents" project. This quality control system identified 15 % bioanalytical runs as non-compliant to the predefined specifications and ensured the reliable quantification of 940 pharmacodynamic samples. The inter-run assessment of quality controls was able to demonstrate the comparability of the study results. Furthermore, 86 % of incurred sample reanalysis pairs complied with regulatory requirements (>67 %), thus underlining the long-term reproducibility of the utilized ligand-binding assay. Successful participation in interlaboratory testing confirmed the accuracy of the applied method throughout the entire study period. Further investigations showed no notable differences between the five applied lots of the PRA assay. The applicability of this quality control system was proven in an academic environment and ensured reliable results for PRA over the entire 24-month study period., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Aims: Neurohormonal activation characterizes chronic heart failure (HF) and is a well-established therapeutic target. Neurohormonal activation may also play a key role in acute HF (AHF). We aim to describe the association between plasma renin activity (PRA) and three AHF outcomes: (i) worsening HF or death through day 5 of hospitalization; (ii) HF rehospitalization or death through day 30; and (iii) all-cause death through day 30., Methods and Results: A secondary analysis of the BLAST-AHF trial was performed. Eligible patients had a history of HF, elevated natriuretic peptides, signs and symptoms of HF, systolic blood pressure >120 mmHg, and an estimated glomerular filtration rate between 20-75 mL/min/1.73 m 2 . The primary trial was neutral, with no differential effect of study drug by PRA levels. Baseline PRA levels were grouped into tertiles. Adjusted Cox proportional hazard model determined the association of PRA levels with outcomes (α set at P < 0.05). Of 618 randomized patients, 578 (93.5%) had a baseline PRA. PRA was modestly, but significantly, associated with each outcome without adjustment [worsening HF or death through day 5: hazard ratio (HR) 1.11, 95% confidence interval (CI) 1.01-1.23, P = 0.04; HF rehospitalization or death through day 30: HR 1.13, 95% CI 1.02-1.26, P = 0.02; all-cause death through day 30: HR 1.18, 95% CI 1.02-1.37, P = 0.03]. After multivariable adjustment, PRA was only significantly associated with HF rehospitalization or death through day 30 (HR 1.15, 95% CI 1.01-1.32, P = 0.04)., Conclusion: Baseline PRA levels are associated with increased risk for the composite of 30-day HF rehospitalization or death in patients with AHF., (© 2019 The Authors. European Journal of Heart Failure © 2019 European Society of Cardiology.)

During the malignant phase of hypertension in patients with primary aldosteronism complicated with severe renal failure, the plasma renin activity may markedly increase with a false negative screening result for primary aldosteronism, thus potentially leading to a missed diagnosis of primary aldosteronism. We herein report the case of 37-year-old man who presented with accelerated-malignant hypertension complicated with severe renal insufficiency. The plasma renin activity was markedly increased in the malignant phase of hypertension, which were atypical results for primary aldosteronism. However, a plain abdominal computed tomography scan revealed a left adrenal nodule, which was diagnosed as aldosterone-producing adenoma by adrenal venous sampling.

Heart failure (HF) patients frequently have elevated plasma renin activity. We examined the significance of elevated plasma renin activity in a translationally-relevant model of dilated cardiomyopathy (DCM), which replicates the progressive stages (A-D) of human HF. Female mice with DCM and elevated plasma renin activity concentrations were treated with a direct renin inhibitor (aliskiren) in a randomized, blinded fashion beginning at Stage B HF. By comparison to controls, aliskiren treatment normalized pathologically elevated plasma renin activity ( p < 0.001) and neprilysin levels ( p < 0.001), but did not significantly alter pathological changes in plasma aldosterone, angiotensin II, atrial natriuretic peptide, or corin levels. Aliskiren improved cardiac systolic function (ejection fraction, p < 0.05; cardiac output, p < 0.01) and significantly reduced the longitudinal development of edema (extracellular water, p < 0.0001), retarding the transition from Stage B to Stage C HF. The normalization of elevated plasma renin activity reduced the loss of body fat and lean mass (cachexia/sarcopenia), p < 0.001) and prolonged survival ( p < 0.05). In summary, the normalization of plasma renin activity retards the progression of experimental HF by improving cardiac systolic function, reducing the development of systemic edema, cachexia/sarcopenia, and mortality. These data suggest that targeting pathologically elevated plasma renin activity may be beneficial in appropriately selected HF patients.

Regardless of the cause, symptomatic heart failure (HF) with reduced ejection fraction (rEF) is characterized by pathological activation of the renin-angiotensin-aldosterone system (RAAS) with sodium retention and extracellular fluid expansion (edema). Here, we review the role of active renin, a crucial, upstream enzymatic regulator of the RAAS, as a prognostic and diagnostic plasma biomarker of heart failure with reduced ejection fraction (HFrEF) progression; we also discuss its potential as a pharmacological bio-target in HF therapy. Clinical and experimental studies indicate that plasma renin activity is elevated with symptomatic HFrEF with edema in patients, as well as in companion animals and experimental models of HF. Plasma renin activity levels are also reported to be elevated in patients and animals with rEF before the development of symptomatic HF. Modulation of renin activity in experimental HF significantly reduces edema formation and the progression of systolic dysfunction and improves survival. Thus, specific assessment and targeting of elevated renin activity may enhance diagnostic and therapeutic precision to improve outcomes in appropriate patients with HFrEF.

Background: Interindividual variability in blood pressure (BP) response to antihypertensives has been reported. Although plasma renin activity (PRA) is a potential biomarker for personalizing antihypertensive therapy in European American (EA) and African American (AA) hypertensives, clinical utility of PRA-guided prescribing is incompletely understood., Methods: Using systematic-phased approach, PRA's clinical utility was assessed. After categorizing by baseline PRA, clinic systolic BP (SBP) responses to metoprolol and chlorthalidone were compared in 134 EAs and 102 AAs enrolled in the Pharmacogenomics Evaluation of Antihypertensive Responses-2 (PEAR-2) trial. Receiver operating characteristic (ROC) analysis was conducted in EAs. Data from PEAR-2 AAs were used to estimate an optimal PRA cut point using multivariable linear regression models. The derived cut point in AAs was tested in a meta-analysis of 2 independent AA cohorts, and its sensitivity and specificity were assessed., Results: EAs with PRA < 0.65 ng/ml/hour had a greater decrease in SBP to chlorthalidone than metoprolol (by -15.9 mm Hg, adjusted P < 0.0001), whereas those with PRA ≥ 0.65 ng/ml/hour had a greater decrease in SBP to metoprolol than chlorthalidone (by 3.3 mm Hg, adjusted P = 0.04). Area under ROC curve (0.69, P = 0.0001) showed that PRA can predict SBP response among EAs. However, we observed no association between PRA and SBP response in PEAR-2 AAs. Among independent AA cohorts, those with PRA ≥ 1.3 ng/ml/hour (PEAR-2-derived cut point) responded better to atenolol/candesartan than hydrochlorothiazide (meta-analysis P = 0.01). However, sensitivity of the derived cut point was 10%., Conclusions: PRA at the previously established 0.60-0.65 ng/ml/hour cut point is an effective predictive biomarker of BP response in EAs. However, we were unable to identify PRA cut point that could be used to guide antihypertensive selection in AAs., Trial Registration: NCT01203852, NCT00246519, NCT00005520., (© American Journal of Hypertension, Ltd 2019. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Background: Plasma renin activity (PRA) is associated with cardiovascular events in patients with heart failure (HF), but its prognostic role in acute myocardial infarction (AMI) is unclear.Methods and Results:A total of 878 patients with information on baseline PRA on admission were selected from 1,055 AMI patients who underwent emergency coronary angiography between 2007 and 2016. The patients were divided into 2 groups according to their median PRA (2.0 ng/mL/h). The primary endpoint was major adverse cardiac events (MACE), defined as a composite of cardiovascular death and hospitalization because of HF. During follow-up (median 4.5±3.1 years), MACE occurred in 108 patients. Kaplan-Meier analysis showed that the high PRA group had significantly lower MACE-free survival than the low PRA group (log-rank P=0.0009). By multivariate analysis, high PRA was an independent predictor of MACE (hazard ratio (HR) 1.573; 95% confidence interval (CI) 1.049-2.396, P=0.0282). Similarly, among 580 patients who had not been previously treated with renin-angiotensin system inhibitors or β-blockers on admission, high PRA was an independent predictor of MACE (HR 1.732; 95% CI 1.010-3.047, P=0.0460)., Conclusions: In the studied AMI patients, elevated levels of PRA were independently associated with poor prognosis.

Introduction:: The aim of the study was to evaluate clinical and biochemical differences between patients with low-renin and high-renin primary arterial hypertension (AH), mainly in reference to serum lipids, and to identify factors determining lipid concentrations., Materials and Methods:: In untreated patients with AH stage 1 we measured plasma renin activity (PRA) and subdivided the group into low-renin (PRA < 0.65 ng/mL/h) and high-renin (PRA ⩾ 0.65 ng/mL/h) AH. We compared office and 24-h ambulatory blood pressure, serum aldosterone, lipids and selected biochemical parameters between subgroups. Factors determining lipid concentration in both subgroups were assessed in regression analysis., Results:: Patients with high-renin hypertension ( N = 58) were characterized by higher heart rate ( p = 0.04), lower serum sodium ( p < 0.01) and aldosterone-to-renin ratio ( p < 0.01), and significantly higher serum aldosterone ( p = 0.03), albumin ( p < 0.01), total protein ( p < 0.01), total cholesterol ( p = 0.01) and low-density lipoprotein cholesterol (LDL-C) ( p = 0.04) than low-renin subjects ( N = 39). In univariate linear regression, only PRA in the low-renin group was in a positive relationship with LDL-C ( R 2 = 0.15, β = 1.53 and p = 0.013); this association remained significant after adjustment for age, sex, and serum albumin and aldosterone concentrations., Conclusions:: Higher serum levels of total and LDL-C characterized high-renin subjects, but the association between LDL-C level and PRA existed only in low-renin primary AH.

Renin-angiotensin-aldosterone system (RAAS) plays a crucial role in maintaining water and electrolytes homoeostasis, and its deregulation contributes to the development of arterial hypertension. Since the historical description of the "classical" RAAS, a dramatic increase in our understanding of the molecular mechanisms underlying the development of both essential and secondary hypertension has occurred. Approximatively 25% of the patients affected by arterial hypertension display low-renin levels, a definition that is largely arbitrary and depends on the investigated population and the specific characteristics of the assay. Most often, low-renin levels are expression of a physiological response to sodium-volume overload, but also a significant number of secondary hereditary or acquired conditions falls within this category. In a context of suppressed renin status, the concomitant examination of plasma aldosterone levels (which can be inappropriately elevated, within the normal range or suppressed) and plasma potassium are essential to formulate a differential diagnosis. To distinguish between the different forms of low-renin hypertension is of fundamental importance to address the patient to the proper clinical management, as each subtype requires a specific and targeted therapy. The present review will discuss the differential diagnosis of the most common medical conditions manifesting with a clinical phenotype of low-renin hypertension, enlightening the novelties in genetics of the familial forms., (© 2018 John Wiley & Sons Ltd.)

Background: The aldosterone/renin ratio (ARR) is recommended to screen for primary aldosteronism (PA) in hypertension. We estimated fully automated chemiluminescence immunoassays (CLIA) for plasma aldosterone concentrations (PAC) and plasma direct renin concentrations (PRC) and investigated their reference intervals in Chinese Han population., Methods: PAC and PRC were measured on a fully automated analyzer (LIAISON XL, DiaSorin, Italy). Performance characteristics were estimated according to CLSI approved guidelines. 328 healthy individuals were selected for reference intervals investigation. Results simultaneously tested by CLIA and radioimmunoassays were reviewed from 123 patients with hypertension and/or adrenal space-occupying lesion. PAC/PRC ratio (ARR prc ) was compared to PAC/plasma renin activity (PRA) ratio (ARR pra )., Results: Within-laboratory imprecision was 5.6%-6.7% for PAC and 3.0%-3.3% for PRC. The LoQ was 72.2 pmol/L for PAC and 1.27 mIU/L for PRC. Linearity was excellent in the range of concentrations between 94 and 2708 pmol/L for PAC and 1.3-461.8 mIU/L for PRC. Interferences of hemoglobin, unconjugated bilirubin and lipaemia could be acceptable, but not of conjugated-bilirubin when renin and aldosterone at low concentrations. The central 95% reference intervals for males: PAC: 76-722 pmol/L, PRC: 3.3-92.7 mIU/L, ARR: 2.2-46.0 pmol/mIU; for females: PAC: 85-1010 pmol/L, PRC: 3.7-99.8 mIU/L, ARR: 3.6-68.4 pmol/mIU. Upper reference limits for ARR of younger and older men were lower than women. ARR prc and ARR pra showed almost perfect agreement (kappa = 0.815) for screening PA., Conclusion: The DiaSorin tests are valuable analytical options for PAC and PRC measurements. We recommend sex-specific and age-specific reference intervals of these items should be estimated., (Copyright © 2018 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.)

Objectives: This study examined the association of aldosterone and plasma renin activity (PRA) with incident cardiovascular disease (CVD), using a composite endpoint of coronary heart disease, stroke, and/or heart failure and mortality among African Americans in the Jackson Heart Study., Background: There is a paucity of data for the association of aldosterone and PRA with incident CVD or all-cause mortality among community-dwelling African Americans., Methods: A total of 4,985 African American adults, 21 to 94 years of age, were followed for 12 years. Aldosterone, PRA, and cardiovascular risk factors were collected at baseline (from 2000 to 2004). Incident events included coronary heart disease and stroke (assessed from 2000 to 2011) and heart failure (assessed from 2005 to 2011). Cox models were used to estimate hazard ratios (HRs) for incident CVD and mortality, adjusting for age, sex, education, occupation, current smoking, physical activity, dietary intake, and body mass index., Results: Among 4,160 participants without prevalent CVD over a median follow-up of 7 years, there were 322 incident CVD cases. In adjusted analyses, each 1-U SD increase in log-aldosterone and log-PRA were associated with HR of 1.26 (95% confidence intervals [CI]: 1.14 to 1.40) and 1.16 (95% CI: 1.02 to 1.33) for incident CVD, respectively. Over a median of 8 years, 513 deaths occurred among 4,985 participants. In adjusted analyses, each 1-U SD increase in log-aldosterone and log-PRA were associated with HRs of 1.13 (95% CI: 1.04 to 1.23) and 1.12 (95% CI: 1.01 to 1.24) for mortality, respectively., Conclusions: Elevated aldosterone and PRA may play a significant role in the development of CVD and all-cause mortality among African Americans., (Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background and Aims: In experimental investigations conducted in rats, raising serum uric acid (SUA) levels resulted in the stimulation of intrarenal renin expression. Studies in humans exploring the association of SUA with plasma renin activity (PRA) yielded conflicting results. Moreover, little is known about the relationship of SUA with plasma aldosterone concentration (PAC). The study aimed to assess the relationship between SUA levels, PRA, and PAC and the influence of age, gender, body mass index (BMI), and hyperuricemia on these relationships in subjects with essential hypertension (EH)., Methods and Results: We enrolled 372 hypertensive patients (mean age 45 ± 12 years, men 67%) with uncomplicated EH that was not pharmacologically treated. The study population was divided in tertiles according to SUA levels. While PRA did not differ significantly across the three tertiles, PAC was higher in subjects belonging to the uppermost tertile of SUA than those in the lower ones (p = 0.0429); however, this difference lost statistical significance after adjustment for age, sex, BMI, and serum creatinine. Univariate correlation analyses showed significant associations of SUA with PRA (r = 0.137; p = 0.008) and PAC (r = 0.179; p < 0.001). However, these relationships were not significant after correcting for confounding factors in multiple linear regression analyses. We did not observe statistically significant effect modification by gender, age, BMI, and hyperuricemia., Conclusion: SUA levels are weakly associated with PRA and PAC in adults with untreated EH. These relationships were lost after adjustment for age, sex, BMI, and serum creatinine., (Copyright © 2016 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.)

Low birth weight and prematurity are risk factors for hypertension in adulthood. Few studies in preterm or full-term born children reported on plasma renin activity (PRA). We tested the hypothesis that renin might modulate the incidence of hypertension associated with prematurity. We enrolled 93 prematurely born children with birth weight <1000 g and 87 healthy controls born at term, who were all examined at ≈11 years. Renal length and glomerular filtration rate derived from serum cystatin C were 0.28 cm (95% confidence interval, 0.09-0.47) and 11.5 mL/min per 1.73 m 2 (6.4-16.6) lower in cases, whereas their systolic/diastolic blood pressure (BP) was 7.5 mm Hg (4.8-10.3)/4.0 mm Hg (2.1-5.8) higher ( P <0.001 for all). The odds of having systolic prehypertension or systolic hypertension associated with extreme low birth weight were 6.43 (2.52-16.4; P <0.001) and 10.9 (2.46-48.4; P =0.002). Twenty-four hours of urinary sodium excretion was similar in cases and controls (102.1 versus 106.8 mmol; P =0.47). Sodium load per nephron was estimated as sodium excretion divided by kidney length (mmol/cm). PRA was 0.54 ng/mL per hour (0.23-0.85; P =0.001) lower in cases. PRA, systolic BP, and sodium load were available in 43 cases and 56 controls. PRA decreased with systolic BP (slope -0.022 ng/mL per hour/ - mm Hg ; P =0.048), but was unrelated to sodium load (slope +0.13 mmol/cm - mm Hg =0.17) in cases and controls. In conclusion, extremely low birth weight predisposes young adolescents to low-renin hypertension, but does not affect the inverse association between PRA and BP.P =0.54). The slope of PRA on systolic BP was similar ( P =0.17) in cases and controls. In conclusion, extremely low birth weight predisposes young adolescents to low-renin hypertension, but does not affect the inverse association between PRA and BP., Clinical Trial Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02147457., (© 2017 American Heart Association, Inc.)

Patients with nondipper hypertension are known to carry a high risk of cardiovascular complications. Vitamin D deficiency is associated with hypertension. Because vitamin D deficiency activates the renin-angiotensin-aldosterone system (RAAS), we hypothesized that this vitamin would interact with the RAAS to influence blood pressure (BP) in nondipper hypertensive patients. We performed a cross-sectional analysis of 1,007 outpatients with hypertension (HTN). Dipper and nondipper patterns were detected, and the two groups were matched for clinical, laboratory, 25-hydroxyvitamin D (25OHD) levels, and ambulatory blood pressure recording. Plasma renin activity (PRA), angiotensin II, and plasma aldosterone concentration (PAC) were assessed in 174 patients treated with calcium channel blockers or no medication. The mean 25OHD concentration in the entire study population was 12.3ng/dL, and the prevalence of vitamin D deficiency was 87.0%. Dipper and nondipper HTN were noted in 187 patients (24.6%) and 573 patients (75.4%). 25OHD levels were similar between nondipper and dipper HTN groups. Forward stepwise logistic regression analysis showed that BMI and age were independent predictors of nondipper HTN. Neither 25OHD levels nor RAAS components were included in the model. In correlation analyses, nocturnal decline of diastolic BP was positively associated with 25OHD levels and standing PRA (r = 0.152 p = 0.045, r = 0.165 p = 0.038, respectively). The present study showed that vitamin D deficiency was astonishingly prevalent in hypertensive subjects residing in Xinjiang, China. There may be a weakly association of nocturnal DBP decline with 25OHD levels and standing PRA levels. We found no association between vitamin D deficiency and nondipper HTN.

Background: Several approaches to initiation of antihypertensive therapy have been suggested. These include thiazide diuretics (TDs) as the first drug in all patients, initial drug selection based on age and race criteria, or therapy selection based on measures of plasma renin activity (PRA). It is uncertain which of these strategies achieves the highest control rate with monotherapy in Stage-I hypertension. We sought to compare control rates among these strategies., Methods: We used data from the Pharmacogenomic Evaluation of Antihypertensive Responses study (PEAR) to estimate control rates for each strategy: (i) TD for all, (ii) age- and race-based strategy: Hydrochlorothiazide (HCTZ) for all blacks and for whites ≥50 years and a renin-angiotensin system inhibitor (atenolol) for whites <50 years) or (iii) a PRA based strategy: HCTZ for suppressed PRA (<0.6ng/ml/h) and atenolol for non-suppressed PRA (≥0.6ng/ml/h) despite age or race. Hypertension was confirmed prior to treatment with HCTZ (148 blacks and 218 whites) or with atenolol (146 blacks and 221 whites)., Results: In the overall sample, using clinic blood pressure (BP) response, the renin-based strategy was associated with the greatest control rate (48.9% vs. 40.8% with the age and race-based strategy (P = 0.0004) and 31.7% with the TD for all strategy (P < 0.0001)). The findings were similar using home or by 24-hour ambulatory BP responses and within each racial subgroup., Conclusions: A strategy for selection of initial antihypertensive drug therapy based on PRA was associated with greater BP control rates compared to a thiazide-for-all or an age and race-based strategy., (© American Journal of Hypertension, Ltd 2016. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Propose: To evaluate relationships between optic nerve head (ONH) circulation by laser speckle flowgraphy (LSFG), and secretion levels of plasma norepinephrine (NE), plasma renin activity (PRA), plasma aldosterone concentration (PAC), and plasma cortisol., Method: Forty subjects were included in the study. The mean blur rates (MBR) throughout the ONH (MBR-all), in the tissue (MBR-tissue), and in vessels (MBR-vessel) were analyzed. In 29 subjects the following parameters were evaluated: plasma NE and ONH circulation in the evening and morning (Δ plasma NE, Δ MBR-all, -tissue, -vessel, and Δ area ratio of blood stream)., Results: Plasma NE was significantly correlated with MBR-all (r = 0.39, P = 0.01) and MBR-vessel (r = 0.51, P = 0.0008). Plasma cortisol was significantly correlated with MBR-vessel (r =0.35, P = 0.03). The PRA (r = 0.31, P = 0.05) and PAC (r = 0.31, P = 0.05) tended to correlate with MBR-vessel. The multiple regression analysis revealed that plasma NE, PAC, and ocular perfusion pressure (OPP) were identified as factors contributing independently to the MBR-vessel (plasma NE: standard regression = 0.48, t-value = 3.12, P = 0.004; PAC: 0.43, 3.10, 0.04; OPP: 0.58, 2.34, 0.03, r = 0.71). Positive correlations between Δ plasma NE and Δ MBR-all (r = 0.46, P = 0.01), Δ MBR-tissue (0.38, 0.04), Δ MBR-vessel (0.41, 0.03), and Δ area ratio of blood stream (0.38, 0.04) were observed., Conclusion: Our results clarified that the measurements of ONH circulation by LSFG is reflecting the plasma secretion levels of vasoactive mediators.

Accurate determination of plasma renin activity (PRA) is essential for the development and maintenance of an effective screening program for primary aldosteronism (PA). PRA measurement can also be useful in the investigation of renal artery stenosis, syndrome of mineralocorticoid excess, Addison's disease, congenital adrenal hyperplasia, Bartter and Gitelman syndromes, and for inherited defects in the renin angiotensin aldosterone system (RAAS). We describe a semi-automated and simple method for the accurate and precise measurement of PRA from 500 μL of plasma (250 μL if blank subtraction is omitted, as discussed) using a liquid chromatography and tandem mass spectrometry (LC-MS/MS) method for angiotensin I (AngI) in 96-well format. After a 3 h AngI generation step at 37 °C in buffering conditions at pH 6, the reaction is quenched with 10 % formic acid containing AngI internal standard. Sample preparation then proceeds with offline solid phase extraction, two wash steps, and methanol elution followed by injection into the LC-MS/MS system. Quantitation is performed against a 7-point calibration linear curve prepared in buffer. The assay calibration range is 0.34-30.0 ng/mL which corresponds to PRA values of 0.11-10.0 ng/mL/h: much wider than was possible using traditional competitive antibody-based methods. Total precision in clinical production has been observed to be 5.8 to 5.0 % for Bio-Rad Hypertension Control materials having nominal PRA values ranging from 1.73 to 12.43 ng/mL/h. At AngI concentrations of 0.06 ng/L (corresponding to a PRA of 0.02 ng/mL/h), signal to noise ratios are 50:1 indicating that the limit of quantitation is well below the level required for clinical use.

Primary aldosteronism (PA) is estimated to occur in 5-12% of patients with hypertension. Assessment of aldosterone / plasma renin activity (PRA) ratio (ARR) has been used as a screening test in patients suspected of PA. Direct determination of renin (DRC) and calculation of aldosterone / direct renin concentration ratio (ADRR) could be similarly useful for screening patients suspected of PA. The study included 62 patients with indication for evaluation of the renin-angiotensin-aldosterone system and 35 healthy volunteers. In all participants we measured concentrations of serum aldosterone, plasma direct renin, and PRA after a night's rest and again after walking for two hours. The concentrations of aldosterone, direct renin, and PRA were measured by isotopic methods (radioimmunoassay (RIA) / immunoradiometric assay (IRMA)). Correlations of ARR with ADRR in the supine position were r = 0.9162, r(2) = 0.8165 (p < 0.01); and in the up-right position were r = 0.7765, r(2) = 0.9153 (p < 0.01). The cut-off values of ARR and ADRR ≥ 100 presented highest specificity (99%) for the diagnosis of PA; however, quite acceptable specificity and sensitivity (> 80% and 100%, respectively) appeared for the ratios ≥ 30. We suggest that for practical and economic reasons ARR can be replaced by ADRR., (© The Author(s) 2014.)

Introduction: Performing measurements of plasma renin activity (PRA) or direct renin concentration (DRC) and aldosterone concentration, we should be well informed about requirements concerning blood sample processing., Material and Methods: Forty-seven patients had blood collected in the supine and upright positions. Blood was withdrawn into two EDTA2K tubes and one with clot activator. One EDTA2K tube was cooled at +4 °C and centrifuged at +4 °C whereas the other was prepared at room temperature. PRA and DRC were measured by radioimmunoassay (RIA) and radioimmunometry (IRMA), respectively, in both cooled and not cooled plasma samples, and aldosterone was measured by RIA in not cooled plasma and in serum., Results: In all the groups, with low, medium, and high values of PRA and direct renin, the temperature of sample processing within 30 minutes had no marked influence on the final result (correlation coefficient for renin was 0.9994, and for PRA, 0.8297). The measured concentrations of aldosterone also showed high correlation (r = 0.9790) but were markedly higher in plasma., Conclusion: The measurements of DRC, and to a lesser extent PRA, were similar regardless of temperature condition during the 20-30 minutes necessary for blood sample processing. Aldosterone concentrations in plasma vs serum samples appeared to be markedly higher., (© The Author(s) 2013.)

Purpose: We tested five different angiotensin converting enzyme inhibitors (ACEI) as mitigators of experimental radiation nephropathy at drug doses calibrated to the plasma renin activity (PRA). This was done to determine whether all ACEI had the same efficacy as mitigators of radiation nephropathy when used at drug doses that gave equivalent suppression of the renin angiotensin system., Method: 10 Gy total body irradiation with bone marrow transplantation was used to cause radiation nephropathy in barrier-maintained rats. Equivalent ACEI doses were determined based on their effect to inhibit angiotensin converting enzyme (ACE) and raise the PRA in unirradiated animals., Results: PRA-equivalent doses were found for captopril, lisinopril, enalapril, ramipril and fosinopril. These doses overlap the human doses of these drugs on a body surface area basis. All ACE inhibitors, except fosinopril, mitigated radiation nephropathy; captopril was a somewhat better mitigator than lisinopril, enalapril or ramipril., Conclusions: Most, but not all, ACEI mitigate radiation nephropathy at doses that overlap their clinically-used doses (on a body surface area basis). Fosinopril is known to be an ineffective mitigator of radiation pneumonitis, and it also does not mitigate radiation nephropathy. These pre-clinical data are critical in planning human studies of the mitigation of normal tissue radiation injury.

Background: Aldosterone to renin ratio (ARR) is used in screening for primary aldosteronism (PA). However, there are only few studies on the influence of assay methods on ARR and its cut-off limits., Methods: Plasma direct renin immunoreactivity by chemiluminescence immunoassay (DR) was compared to renin activity assay (PRA), and a specific liquid chromatography-mass spectrometric method (LC-MS/MS) to radioimmunoassay (RIA) for plasma aldosterone. There were 75 samples for renin assays, and 42 samples of 39 patients for both renin and aldosterone assays. PA screening was considered positive if ARR by the aldosterone RIA:PRA was ≥800pmol/L:μg/L/h or by LC-MS/MS:DR≥44pmol/L:ng/L., Results: The correlation between the DR and PRA methods (n=75, r(2)=0.845) and between LC-MS/MS and RIA (n=42, r(2)=0.973) was high in general, but low between the renin methods (n=49, r(2)=0.435) at low PRA values. When ARR was used in screening for PA, there were three divergent cases (positive only by alternative methods), but when applied in combination with criteria for elevated aldosterone, the methods showed good agreement, resulting in eight positive and 31 negative screening results., Conclusions: The automated DR assay combined with LC-MS/MS method for aldosterone provides a rapid, reliable, and specific method for screening of PA., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Objective: To report a case of difficult-to-treat hypertension ultimately managed with triple antirenin (anti-R) therapy using plasma renin activity (PRA) to guide medication selection., Case Summary: A 66-year-old white man was referred to the cardiology pharmacotherapy clinic for difficult-to-treat hypertension. His initial office blood pressure (BP) was 152/71 mm Hg on diltiazem and chlorthalidone. After a series of medication adjustments based on serial PRA measurements, the patient achieved his target BP with a regimen that included 3 anti-R angiotensin system medications: carvedilol, valsartan, and aliskiren., Discussion: Despite continued progress in the understanding and advances in pharmacological therapy for hypertension, uncontrolled hypertension remains a major problem. The most common strategy to control hypertension is the stepped-care approach with progressive addition of medications to eventually reach BP goal. An alternative approach includes the use of PRA measurements to guide both the addition and removal of drugs in an attempt to effectively control BP. At times, this has the potential to result in a drug regimen that is incongruous with current guidelines and practice recommendations. However, if this results in more effective BP control with the same, or fewer, number of medications, it may represent a reasonable alternative., Conclusion: This case report illustrates a real-world application of PRA-guided therapeutics in a patient with difficult-to-treat hypertension. It highlights how a personalized approach can lead to BP control with a more streamlined regimen than would likely result if a stepped-care approach was used.

Morning blood pressure (BP) surge (MS) has been known to be a predictor of cardiovascular events. Currently, few studies have evaluated the underlying mechanism underlying MS, which may include neurohormonal factors and the renin-angiotensin-aldosterone system (RAAS). This study aimed to examine plasma aldosterone concentration (PAC) and plasma renin activity (PRA) and BP parameters with or without MS in never-treated subjects with essential hypertension. This cross-sectional study included a total of 261 patients (mean age: 48.8 years; 60.5% male) with never-treated essential hypertension who were registered in a working group at The Catholic University of Korea. The patients were divided into the MS group, which was defined as having the highest quartile of morning BP increase from sleep (>31 mmHg; n = 66) and the non-MS group (≤31 mmHg; n = 195). We collected 24-h ambulatory BP, pulse wave velocity, ankle brachial index, PAC and PRA from all patients. The measured PAC and PRA were lower in the MS group than in the non-MS group (PAC: 9.0 ± 5.4 ng/dl versus 12.2 ± 8.7 ng/dl, p < 0.001; PRA: 1.7 ± 1.3 ng/ml/h versus 2.6 ± 3.6 ng/ml/h, p = 0.002). The MS group had greater variations in daytime, nighttime and 24-h systolic blood pressure (SBPs) than the non-MS group (24-h SBP: 15.6 ± 4.4 mm Hg for the non-MS group and 18.9 ± 4.9 mmHg for the MS group; p < 0.001 for each). It is generally accepted that the sympathetic nervous system plays a major role in the regulation of BP variability. Therefore, further studies on sympathetic nervous system activation in hypertensives with extreme MS are needed. MS in enrolled patients who were at relatively low risk in this study may be less affected by the RAAS.

Objective: To report a case of difficult-to-treat hypertension ultimately managed with triple antirenin (anti-R) therapy using plasma renin activity (PRA) to guide medication selection., Case Summary: A 66-year-old white man was referred to the cardiology pharmacotherapy clinic for difficult-to-treat hypertension. His initial office blood pressure (BP) was 152/71 mm Hg on diltiazem and chlorthalidone. After a series of medication adjustments based on serial PRA measurements, the patient achieved his target BP with a regimen that included 3 anti-R angiotensin system medications: carvedilol, valsartan, and aliskiren., Discussion: Despite continued progress in the understanding and pharmacological therapy for hypertension, uncontrolled hypertension remains a major problem. The most common strategy to control hypertension is the stepped-care approach, with progressive addition of medications to eventually reach the BP goal. An alternative approach includes the use of PRA measurements to guide both the addition and removal of drugs in an attempt to effectively control BP. At times, this has the potential to result in a drug regimen that is incongruous with current guidelines and practice recommendations. However, if this results in more effective BP control with the same, or fewer, number of medications, it may represent a reasonable alternative., Conclusion: This case report illustrates a real-world application of PRA-guided therapeutics in a patient with difficult-to-treat hypertension. It highlights how a personalized approach can lead to BP control with a more streamlined regimen than would likely result if a stepped-care approach was used.

Background: A plasma renin activity (PRA)-guided strategy is more effective than standard care in treating hypertension (HTN). However, its clinical implementation has been slow, presumably due in part to economic concerns. We estimated the cost effectiveness of a PRA-guided treatment strategy compared with standard care in a treated but uncontrolled HTN population., Methods: We estimated costs, quality-adjusted life years (QALYs), and the incremental cost-effectiveness ratio (ICER) of PRA-guided therapy compared to standard care using a state-transition simulation model with alternate patient characteristic scenarios and sensitivity analyses. Patient-specific inputs for the base case scenario, males average age 63 years, reflected best available data from a recent clinical trial of PRA-guided therapy. Transition probabilities were estimated using Framingham risk equations or derived from the literature; costs and utilities were derived from the literature., Results: In the base case scenario for males, the lifetime discounted costs and QALYs were $23,648 and 12.727 for PRA-guided therapy and $22,077 and 12.618 for standard care, respectively. The base case ICER was $14,497/QALY gained. In alternative scenario analyses varying patient input parameters, the results were sensitive to age, gender, baseline systolic blood pressure, and the addition of cardiovascular risk factors. Univariate sensitivity analyses demonstrated that results were most sensitive to varying the treatment effect of PRA-guided therapy and the cost of the PRA test., Conclusions: Our results suggest that PRA-guided therapy compared with standard care increases QALYs and medical costs in most scenarios. PRA-guided therapy appears to be most cost effective in younger persons and those with more cardiovascular risk factors., (© American Journal of Hypertension, Ltd 2013. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Background: Impairment of kidney function is frequently observed in chronic heart failure (CHF). It correlates with clinical and neurohormonal status, and affects prognosis. We aimed to identify the prognostic impact of plasma renin activity (PRA) in patients affected by CHF with chronic kidney disease (CKD)., Methods: We enrolled 996 consecutive CHF patients (age 65 ± 13 years, mean ± SD, left ventricular ejection fraction, LVEF, 33 ± 10%), who underwent a complete clinical and neurohormonal characterization and were then followed-up (median 36 months) for the end point of cardiac death., Results: A stage ≥ 3 CKD (estimated glomerular filtration rate <60 mL/min/1.73 m(2)) was found in 437 patients. Impaired renal function was associated with worse symptoms, lower LVEF, higher plasma norepinephrine, NT-proBNP and PRA (all p<0.001). As compared to patients with preserved renal function, those with CKD had higher cardiac mortality [106 (24%) vs 53 (9.5%), p<0.001]. In CKD patients, at Cox multivariate analysis, only ejection fraction (HR 0.91, 95% CI 0.84-0.97, p=0.008), NT-proBNP (2.53, 1.45-4.41, p=0.001) and PRA (1.73, 1.16-2.58, p=0.007) were independent predictors of cardiac death. ROC analysis identified a cut-off value for PRA of 3.29 ng/mL/h that predicted prognosis with the greatest accuracy. Finally, the elevation of both NT-proBNP and PRA identified a subset of patients with the highest risk of cardiac death., Conclusions: PRA has an independent prognostic value in CHF patients with CKD comorbidity. The combination of PRA and NT-proBNP identifies a group of high risk patients, who might benefit of a more intensive care, targeted to enhance renin-angiotensin system antagonism., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

An association has been shown between plasma renin activity (PRA) and the risk of cardiovascular disease. There is also evidence that angiotensin II exerts detrimental effects on progression and instabilization of atherosclerotic plaque. The renin-angiotensin system (RAS) can be inhibited through inhibition of angiotensin I (Ang I) generation from angiotensinogen by direct renin inhibitors, inhibition of angiotensin II (Ang II) generation from angiotensin I by angiotensin-converting enzyme inhibitors and finally by direct inhibition of the action of Ang II receptor level. Aliskiren, the first direct renin inhibitor to reach the market, is a low-molecular-weight, orally active, hydrophilic nonpeptide. Aliskiren blocks Ang I generation, while plasma renin concentration increases because the drugs blocks the negative feed-back exerted by Ang II on renin synthesis. Because of its long pharmacological half-life, aliskiren is suitable for once-daily administration. Its through-to-peak ratio approximates 98% for the 300 mg/day dose. Because of its mechanism of action, aliskiren might offer the additional opportunity to inhibit progression of atherosclerosis at tissue level. Hypertension is an approved indication for this drug, which is also promising for the treatment of heart failure. The efficacy of this drug in reducing major clinical events is being tested in large ongoing clinical trials.

Background: It is well-accepted that antihypertensive therapy is the cornerstone of treatment for abdominal aortic aneurysm (AAA) patients with hypertension. Direct-acting vasodilators were used in the treatment of hypertension by directly relaxing vascular smooth muscle but may have destructive effects on the aortic wall by activating the renin-angiotensin system axis. Their roles in AAA disease remain to be elucidated. In this study, we used hydralazine and minoxidil, two classical direct-acting vasodilators, to investigate their influence and potential mechanisms on AAA disease. Methods and results: In this study, we investigated the plasma renin level and plasma renin activity in AAA patients. Simultaneously, age and gender ratiomatched patients diagnosed with peripheral artery disease and varicose veins were selected as the control group using a ratio of 1:1:1. Our regression analysis suggested both the plasma renin level and plasma renin activity are positively associated with AAA development. In view of the well-established relationship between direct-acting vasodilators and increased plasma renin concentration, we established a porcine pancreatic elastase-infused AAA mouse model, followed by oral administration of hydralazine (250 mg/L) and minoxidil (120 mg/L) to investigate effects of direct-acting vasodilators on AAA disease. Our results suggested both hydralazine and minoxidil promoted the progression of AAA with increased aortic degeneration. Mechanistically, the vasodilators aggravated aortic inflammation by increased leukocyte infiltration and inflammatory cytokine secretion. Conclusion and relevance: The plasma renin level and plasma renin activity are positively associated with AAA development. Direct vasodilators aggravated experimental AAA progression, which raised cautionary concerns about their applications in AAA disease. [ABSTRACT FROM AUTHOR]

Background: Renal dynamic scans (RDS) despite being considered the gold standard for the diagnosis of pelvic ureteric junction obstruction (PUJO), fail to help resolve the dilemma about management issues in many patients. Multiple invasive and noninvasive methods are being studied to help the decision-making in these patients. We did this study to find correlation of plasma renin activity (PRA) values and resistive index (RI) on Doppler ultrasound with findings of RDS in patients with the Society for Fetal Urology (SFU) Grades 3 and 4 unilateral hydronephrosis (HDN) and also to determine the cut-off values of PRA and RI that could categorically acknowledge the success of pyeloplasty. Methodology: Twenty patients with SFU Grades 3 and 4 unilateral HDN due to PUJO were enrolled. Demographic details were recorded. All underwent Anderson-Hynes dismembered pyeloplasty. Based on the follow-up RDS scans, these patients could fall into one of three categories- improved (successful), status quo, or deteriorated (unsuccessful). Outcomes were compared based on RDS (split renal function [SRF]), ultrasonography, and Doppler findings were done at 3 months of postoperative period. Results: Follow up period was 3 months after Pyeloplasty. Seventeen patients had successful outcomes based on RDS findings, 12 had improvement in SRF (>5%), and 6 had normal drainage curves (t-t1/2 <10 min). Three patients had indeterminate curves (t-t1/2 between 10 to 20 min). Four had improvement on both the criteria, i.e., SRF and drainage curves. Among the three patients who showed no improvement in RDS, two were in "status quo" category and one patient showed deterioration. Seventeen patients also showed improvement in PRA and RI. No significant correlation between PRA and RI with SRF could be established. However, PRA was found to have good concordance with RDS (90%). Conclusion: No significant correlation could be demonstrated between SRF and the respective values of PRA and RI. However, PRA could act as an adjunct to predict the early success of pyeloplasty in view of good concordance with RDS. A larger trial with bigger cohort of patients is required to confirm our contention. [ABSTRACT FROM AUTHOR]

Background: Reninoma is a rare, benign renal neoplasm. Typical clinical features include severe hypertension, secondary hyperaldosteronism, hypokalaemia and metabolic alkalosis caused by the overproduction of renin. Case presentation: A 25-year-old lean Chinese woman with no family history of hypertension was hospitalized for stage 1 hypertension that gradually developed over two years. Endocrine investigation showed hyperreninemia without hyperaldosteronism and hypokalaemia. Interestingly, although the patient had an elevated plasma renin concentration (PRC), her plasma renin activity (PRA) was in the normal range. Abdominal contrast-enhanced computed tomography (CT) scanning revealed a solid, low-density, renal cortical mass with delayed enhancement. Selective renal vein sampling (SRVS) was performed, and a lateralization of the renin secretion from the left kidney was found. Enucleation of the tumour led to a rapid remission of hypertension and hyperreninemia. Based on pathological findings, the patient was diagnosed with reninoma. Immunohistochemical staining of the tumour was positive for Renin, CD34, Vimentin, and synaptophysin (Syn) and negative for somatostatin receptor 2 (SSTR2) and chromogranin A (CgA). Conclusions: Reninoma can present as mild hypertension without hyperaldosteronism and hypokalaemia. The clinical features of reninoma may depend on the degree of activation of the renin-angiotensin-aldosterone system (RAAS). PRC should be incorporated in the differential diagnosis of secondary hypertension. [ABSTRACT FROM AUTHOR]

Introduction: The aim of this study was to assess the relations between plasma renin activity (PRA), serum aldosterone concentration (ALDO) and selected asymptomatic organ damage (AOD) indices in mild primary arterial hypertension (AH).Material and Methods: We measured PRA, ALDO, and selected AOD indices (carotid-femoral pulse wave velocity (cfPWV), central aortic pulse pressure (cPP), estimated glomerular filtration rate (eGFR)) in 122 patients with untreated AH.Results: Patients with high PRA (≥ 0.65 ng/ml/h) were characterized by lower plasma sodium and aldosterone to renin ratio (ARR), higher ALDO, but a similar level of AOD indices compared to patients with low PRA. cfPWV (p = 0.04) and cPP (p = 0.019) increased with ARR, while eGFR decreased with ALDO (p = 0.008). Only eGFR was independently correlated with ALDO. In subjects with simultaneously high PRA and ARR values, we found significantly higher cfPWV (p = 0.02) and cPP (p = 0.04) and lower eGFR (p = 0.02) than in those with high PRA but low ARR values.Conclusions: Assessment of the influence of the renin-angiotensin-aldosterone system (RAAS) on AOD should include the relationship between renin and aldosterone. The PRA itself has no predictive value for AOD. More advanced arterial stiffness and renal impairment are associated with increased PRA and ARR. The RAAS activity might be useful in AOD prediction and hypertension severity assessment. [ABSTRACT FROM AUTHOR]

Background: To update information about the internationally accepted standards and clinical recommendations for the detection and diagnosis of primary aldosteronism (PA).Methods: The Taiwan Society of Aldosteronism (TSA) Task Force reviewed the latest literature and reached a consensus after group meetings. The nine critical issues were recognized to provide updated information and internationally acceptable protocols.Results: When screening for PA by using the plasma aldosterone concentration (PAC) to plasma renin activity (PRA) ratio (ARR), withdrawal or adjustment of antihypertensive medication is not always necessary on the first patient visit. Hypokalemia should be corrected before ARR screening. In spontaneous hypokalemia, plasma renin below detection levels, and PAC higher than 20 ng/dL (550 pmol/L), further confirmatory testing is unnecessary for PA diagnosis. Direct renin concentration (DRC) could be used for PA diagnosis if PRA is unavailable. Although additional confirmatory tests are suggested, the result of a single test is still reliable. For patient safety, discontinuation or adjustment of antihypertensive medications is indicated before adrenal venous sampling (AVS). ACTH could be beneficial for successful adrenal vein cannulation but is not necessary for determining lateralization in AVS. Simultaneous technique is preferred for AVS. Adrenal NP-59 scintigraphy integrated with SPECT/CT could guide PA management.Conclusion: With introduction of these new concepts to the clinicians, we expect better identification, management and treatment of PA patients. [ABSTRACT FROM AUTHOR]

BackgroundAlthough higher plasma renin activity (PRA) is associated with poor clinical outcomes including higher death and cardiovascular events, its association with prevalence of chronic kidney disease (CKD) is not clear. We hypothesized that higher levels of PRA and lower levels of aldosterone-to-PRA ratios (ARRs) are associated with greater CKD prevalence in a large and ethnically diverse population of southern California who underwent uniform healthcare.MethodsDuring the period 1 January 1998 to 31 October 2009, the adult population who was under the care of Kaiser Permanente Southern California with documented outpatient values of PRA and minimum of 6 months continuous enrollment were examined. CKD defined by an estimated glomerular filtration rate (eGFR) less than 60 ml/min per 1.73 m2. PRA levels and ARR were categorized into quartiles. Multivariate logistic regressions were used to calculate odds ratios for CKD based on PRA controlling for age, sex, black race, diabetes status, hypertension, and type of medication use.ResultsWe identified 9495 individuals including 7887 with hypertension. Study population included 60% women, 35% whites, 20% blacks, 20% Hispanics, and 26% diabetic patients. Adjusted odds ratios (95% confidence interval) for CKD across second, third, and fourth quartiles of PRA quartile (reference: first quartile) were 1.5 (1.2-1.7), 1.5 (1.3-1.8), and 2.2 (1.9-2.6), respectively. Each 10-unit increase in PRA was associated with odds ratio for CKD of 1.3 (1.2-1.4). ARR showed a similar but inverse trend with CKD.ConclusionHigher levels of PRA are associated with greater rates of CKD in our large ethnically diverse population of primarily hypertensive patients. Whether modulation of PRA can mitigate prevalence of CKD needs to be studied in interventional trials.

Background: Despite advances in non‐invasive vascular imaging, detection of renal artery stenosis via catheter angiography is the criterion standard for the diagnosis of renovascular hypertension (RVH). However, because of lack of evidence, the utility of various blood tests and imaging modalities remains unclear. Methods: We retrospectively analyzed the utility of blood tests (plasma renin activity [PRA], aldosterone, and renal vein renin [RVR] values) and imaging studies (computed tomography angiography [CTA], kidney ultrasonography [US]) by comparing them with catheter angiography. Ten pediatric patients with RVH at two institutions from January 2008 to December 2017 were recruited. The sensitivities for diagnosing RVH via imaging and blood tests (kidney [US], PRA, and aldosterone) were derived by examining patient records. Furthermore, the sensitivity and specificity of CT angiography were calculated by considering both the affected and non‐affected renal arteries of the patients. Results: A high sensitivity for diagnosing RVH via kidney US (89%) and PRA (80%) was observed. The sensitivity and specificity of CTA were 100%, each. RVR sampling did not aid in the diagnosis of RVH; only two of six patients with unilateral RVH showed significant laterality of RVR boundary ratios. Renal scintigraphy facilitated detection of a non‐functional kidney (split renal function <5%). Conclusions: RVH in children could be diagnosed utilizing non‐invasive blood and imaging tests, without catheter angiography. We recommend kidney length measurement along with measurement of PRA level, as a simple and highly useful screening test, followed by CTA as a diagnostic test. [ABSTRACT FROM AUTHOR]

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