Albuminuria and cardiovascular risk

Cardiovascular risk (CVR) estimation is a fundamental tool for guiding therapy. Albuminuria indicates target organ damage in an accessible, economic and non-invasive manner. Improves high-risk patient identification, especially in chronic kidney disease (CKD) and diabetes mellitus (DM). In addition, anti-albuminuric treatments may improve CVR. This would position albuminuria as a guide and therapeutic objective. Although the capacity of albuminuria as an epidemiological CVR marker in specific populations (hypertension, CKD, DM) is accepted, its profile as a risk marker in the general population and as a therapeutic target is controversial. There is ambiguous evidence regarding its predictive capacity, added to the fact that treatments such as SLGT2 blockers reduce CVR events regardless of albuminuria presence or magnitude. This review analyzes the available evidence on albuminuria as a CVR marker, a treatment goal and therapeutic guide.

It is strongly recommended to not conduct, fund, or publish research studies that use spot urine samples with estimating equations to assess individuals' sodium (salt) intake in association with health outcomes: a policy statement of the World Hypertension League, International Society of Hypertension and Resolve to Save Lives

Spot urine samples with estimating equations have been used to assess individuals' sodium (salt) intake in association with health outcomes. There is large random and systematic error in estimating sodium intake using this method and spurious health outcome associations. Substantial controversy has resulted from false claims the method is valid. Hence, the World Hypertension League, International Society of Hypertension and Resolve to Save Lives, supported by 21 other health organizations, have issued this policy statement that strongly recommends that research using spot urine samples with estimating equations to assess individuals' sodium (salt) intake in association with health outcomes should not be conducted, funded or published. Literature reviews on the health impacts of reducing dietary sodium that include studies that have used spot and short duration timed urine samples with estimating equations need to explicitly acknowledge that the method is not recommended to be used and is associated with spurious health outcome associations.

Personalised recommendations for hospitalised patients with Acute Kidney Injury using a Kidney Action Team (KAT-AKI): protocol and early data of a randomised controlled trial

INTRODUCTION

Although studies have examined the utility of clinical decision support tools in improving acute kidney injury (AKI) outcomes, no study has evaluated the effect of real-time, personalised AKI recommendations. This study aims to assess the impact of individualised AKI-specific recommendations delivered by trained clinicians and pharmacists immediately after AKI detection in hospitalised patients.

METHODS AND ANALYSIS

KAT-AKI is a multicentre randomised investigator-blinded trial being conducted across eight hospitals at two major US hospital systems planning to enrol 4000 patients over 3 years (between 1 November 2021 and 1 November 2024). A real-time electronic AKI alert system informs a dedicated team composed of a physician and pharmacist who independently review the chart in real time, screen for eligibility and provide combined recommendations across the following domains: diagnostics, volume, potassium, acid-base and medications. Recommendations are delivered to the primary team in the alert arm or logged for future analysis in the usual care arm. The planned primary outcome is a composite of AKI progression, dialysis and mortality within 14 days from randomisation. A key secondary outcome is the percentage of recommendations implemented by the primary team within 24 hours from randomisation. The study has enrolled 500 individuals over 8.5 months. Two-thirds were on a medical floor at the time of the alert and 17.8% were in an intensive care unit. Virtually all participants were recommended for at least one diagnostic intervention. More than half (51.6%) had recommendations to discontinue or dose-adjust a medication. The median time from AKI alert to randomisation was 28 (IQR 15.8-51.5) min.

ETHICS AND DISSEMINATION

The study was approved by the ethics committee of each study site (Yale University and Johns Hopkins institutional review board (IRB) and a central IRB (BRANY, Biomedical Research Alliance of New York). We are committed to open dissemination of the data through clinicaltrials.gov and sharing of data on an open repository as well as publication in a peer-reviewed journal on completion.

TRIAL REGISTRATION NUMBER

NCT04040296.

Results from part A of the multi-center, double-blind, randomized, placebo-controlled NefIgArd trial, which evaluated targeted-release formulation of budesonide for the treatment of primary immunoglobulin A nephropathy

The therapeutic potential of a novel, targeted-release formulation of oral budesonide (Nefecon) for the treatment of IgA nephropathy (IgAN) was first demonstrated by the phase 2b NEFIGAN trial. To verify these findings, the phase 3 NefigArd trial tested the efficacy and safety of nine months of treatment with Nefecon (16 mg/d) versus placebo in adult patients with primary IgAN at risk of progressing to kidney failure (ClinicalTrials.gov: NCT03643965). NefIgArd was a multicenter, randomized, double-blind, placebo-controlled two-part trial. In Part A, 199 patients with IgAN were treated with Nefecon or placebo for nine months and observed for an additional three months. The primary endpoint for Part A was 24-hour urine protein-to-creatinine ratio (UPCR) after nine months. Secondary efficacy outcomes evaluated included estimated glomerular filtration rate (eGFR) at nine and 12 months and the UPCR at 12 months. At nine months, UPCR was 27% lower in the Nefecon group compared with placebo, along with a benefit in eGFR preservation corresponding to a 3.87 ml/min/1.73 m2 difference versus placebo (both significant). Nefecon was well-tolerated, and treatment-emergent adverse events were mostly mild to moderate in severity and reversible. Part B is ongoing and will be reported on later. Thus, NefIgArd is the first phase 3 IgA nephropathy trial to show clinically important improvements in UPCR and eGFR and confirms the findings from the phase 2b NEFIGAN study.

[Implementation of the HEARTS Initiative in Argentina: initial resultsImplementação da Iniciativa HEARTS na Argentina: primeiros resultados]

Las enfermedades cardiovasculares son la principal causa de morbimortalidad, y la hipertensión es su principal factor de riesgo. En 2018, Argentina comenzó a implementar la Iniciativa HEARTS en 5 centros de atención primaria de salud a través del Plan Nacional de Prevención y Control de la Hipertensión Arterial. En este estudio se presenta el impacto de su implementación en los indicadores de cobertura efectiva, tratamiento, tratamiento combinado y control. La Iniciativa HEARTS incluye múltiples componentes; entre ellos se destacan la capacitación de los equipos de salud, la reorganización de las tareas basada en la transferencia de competencias clínicas, la provisión de dispositivos de medición de la presión arterial automáticos y clínicamente validados, y la utilización de un único protocolo de tratamiento estandarizado. Se utilizó un modelo de datos longitudinales del tipo ecuación de estimación generalizada, y se agrupó la información de los 5 centros de salud mediante promedios ponderados según el tamaño de la población bajo cobertura. El análisis de los resultados fue estratificado en dos períodos de tiempo delimitados por la irrupción de las restricciones debidas al COVID-19. Durante el primer período de 18 meses se observó una mejoría significativa en el tratamiento (5,9%; p<0,01) y el tratamiento combinado (13,4%; p<0,01), sin cambios significativos en la cobertura (8,4%; p=0,87) y con un descenso paradojal en el control (−3,3%; p=0,02). Durante las restricciones y respecto del período previo, se constató una reducción generalizada en todos los indicadores, principalmente en la cobertura (−23,6%; p<0,01) y el control (−12,5%; p<0,01). Sin embargo, los niveles de tratamiento y tratamiento combinado persistieron por encima de los valores basales (1,7%; p<0,01 y 5,4%; p<0,01, respectivamente).

Three Times Weekly Dosing of Daprodustat versus Conventional Epoetin for Treatment of Anemia in Hemodialysis Patients: ASCEND-TD: A Phase 3 Randomized, Double-Blind, Noninferiority Trial

BACKGROUND AND OBJECTIVES

Daprodustat is a hypoxia-inducible factor prolyl hydroxylase inhibitor (HIF-PHI) being investigated for the treatment of anemia of CKD. In this noninferiority trial, we compared daprodustat administered three times weekly with epoetin alfa (epoetin) in patients on prevalent hemodialysis switching from a prior erythropoiesis-stimulating agent (ESA).

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Patients on hemodialysis with a baseline hemoglobin of 8-11.5 g/dl receiving an ESA were randomized 2:1 to daprodustat three times weekly (n=270) or conventional epoetin (n=137) for 52 weeks. Dosing algorithms aimed to maintain hemoglobin between 10 and 11 g/dl. The primary end point was mean change in hemoglobin from baseline to the average during the evaluation period (weeks 28-52). The principal secondary end point was average monthly intravenous iron dose. Other secondary end points included BP and hemoglobin variability.

RESULTS

Daprodustat three times weekly was noninferior to epoetin for mean change in hemoglobin (model-adjusted mean treatment difference [daprodustat-epoetin], -0.05; 95% confidence interval, -0.21 to 0.10). During the evaluation period, mean (SD) hemoglobin values were 10.45 (0.55) and 10.51 (0.85) g/dl for daprodustat and epoetin groups, respectively. Responders (defined as mean hemoglobin during the evaluation period in the analysis range of 10 to 11.5 g/dl) were 80% in the daprodustat group versus 64% in the epoetin group. Proportionately fewer participants in the daprodustat group versus the epoetin group had hemoglobin values either below 10 g/dl or above 11.5 g/dl during the evaluation period. Mean monthly intravenous iron use was not significantly lower with daprodustat versus epoetin. The effect on BP was similar between groups. The percentage of treatment-emergent adverse events was similar between daprodustat (75%) and epoetin (79%).

CONCLUSIONS

Daprodustat was noninferior to epoetin in hemoglobin response and was generally well tolerated.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

Anemia Studies in Chronic Kidney Disease: Erythropoiesis via a Novel Prolyl Hydroxylase Inhibitor Daprodustat-Three Times Weekly Dosing in Dialysis (ASCEND-TD), NCT03400033.

Is Isolated Diastolic Hypertension an Important Phenotype?

PURPOSE OF REVIEW

Isolated diastolic hypertension (IDH) is a frequent hypertension phenotype. We review IDH pathophysiology, risk stratification, and therapeutic decisions.

RECENT FINDINGS

Recent guidelines lowering blood pressure cutoff levels have increased IDH prevalence and likely decreased associated cardiovascular risk. Long-term cardiovascular risk and pharmacological intervention in IDH are controversial. Narrow pulse pressure and other physiological and epidemiological characteristics are shared with a systodiastolic hypertension (SDH) subgroup. We propose that IDH be incorporated into a broader category, predominantly diastolic hypertension (PDH), defined by pulse pressure ≤ 45 mmHg and includes IDH and SDH with a narrow pulse pressure. IDH-PDH is associated with cardiovascular risk in the long term, especially in young patients. Standardization of the IDH definition and population may contribute to future research to understand genetics, pathophysiology, and eventually therapy in this important subgroup of hypertensive patients.

Standardized treatment to improve hypertension control in primary health care: The HEARTS in the Americas Initiative

Hypertension is the leading risk factor for cardiovascular disease (CVD) worldwide. Despite the availability of effective antihypertensive medications, the control of hypertension at a global level is dismal, and consequently, the CVD burden continues to increase. In response, countries in Latin America and the Caribbean are implementing the HEARTS in the Americas, a community-based program that focuses on increasing hypertension control and CVD secondary prevention through risk factor mitigation. One key pillar is the implementation of a standardized hypertension treatment protocol supported by a small, high-quality formulary. This manuscript describes the methodology used by the HEARTS in the Americas program to implement a population-based standardized hypertension treatment protocol. It is rooted in a seamless transition from existing treatment practices to best practice using pharmacologic protocols built around a core set of ideal antihypertensive medications. In alignment with recent major hypertension guidelines, the HEARTS in the Americas protocols call for the rapid control of blood pressure, through the use of two antihypertensive medications, preferably in the form of a single pill, fixed-dose combination, in the initial treatment of hypertension. To date, the HEARTS in the Americas program has seen the improvement in antihypertensive medication formularies and the establishment of pharmacologic treatment protocols tailored to individual participating countries. This has translated to significant increases in hypertension control rates post-program implementation in these jurisdictions. Thus, the HEARTS in the Americas program could serve as a model, for not only the Americas Region but globally, and ultimately decrease the burden of CVD.

Implementing standardized performance indicators to improve hypertension control at both the population and healthcare organization levels

The ability to reliably evaluate the impact of interventions and changes in hypertension prevalence and control is critical if the burden of hypertension-related disease is to be reduced. Previously, a World Hypertension League Expert Committee made recommendations to standardize the reporting of population blood pressure surveys. We have added to those recommendations and also provide modified recommendations from a Pan American Health Organization expert meeting for "performance indicators" to be used to evaluate clinical practices. Core indicators for population surveys are recommended to include: (1) mean systolic blood pressure and (2) mean diastolic blood pressure, and the prevalences of: (3) hypertension, (4) awareness of hypertension, (5) drug-treated hypertension, and (6) drug-treated and controlled hypertension. Core indicators for clinical registries are recommended to include: (1) the prevalence of diagnosed hypertension and (2) the ratio of diagnosed hypertension to that expected by population surveys, and the prevalences of: (3) controlled hypertension, (4) lack of blood pressure measurement within a year in people diagnosed with hypertension, and (5) missed visits by people with hypertension. Definitions and additional indicators are provided. Widespread adoption of standardized population and clinical hypertension performance indicators could represent a major step forward in the effort to control hypertension.

Novel RAAS agonists and antagonists: clinical applications and controversies

The renin-angiotensin-aldosterone system (RAAS) regulates blood pressure homeostasis and vascular injury and repair responses. The RAAS was originally thought to be an endocrine system critically important in regulating blood pressure homeostasis. Yet, important local forms of the RAAS have been described in many tissues, which are mostly independent of the systemic RAAS. These systems have been associated with diverse physiological functions, but also with inflammation, fibrosis and target-organ damage. Pharmacological modulation of the RAAS has brought about important advances in preventing morbidity and mortality associated with cardiovascular disease. Yet, traditional RAAS blockers such as angiotensin converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) only reduce the risk of disease progression in patients with established cardiovascular or renal disease by ∼20% compared with other therapies. As more components of the RAAS are described, other potential therapeutic targets emerge, which could provide improved cardiovascular and renal protection beyond that provided by an ACE inhibitor or ARB. This Review summarizes the present and future pharmacological manipulation of this important system.

Preemptive kidney transplantation: experience in two centers

INTRODUCTION

End-stage renal disease (ESRD) is a prevalent, important cause of death. Transplantation increases survival and improves the quality of life of patients with ESRD while long-term dialysis is related to poor outcomes even among patients who undergo subsequent transplantations.

OBJECTIVES

To compare the advantages of preemptive procedures with kidney transplants among patients on renal replacement therapy.

METHODS

This retrospective study was performed in two Córdoba city transplantation centers. Patients were divided into three groups: preemptive kidney transplant (PKT), patients on hemodialysis who received living donor kidney transplants (LDT), and subjects who received grafts from deceased donors (DDT). Serum creatinine, delayed graft function (DGF), subclinical rejection, and interstitial fibrosis/tubular atrophy (IF/TA) were evaluated at 6 months.

RESULTS

Eighty patients were included: PKT (n = 28), LDT (n = 27), DDT (n = 25) mean age 29, 30, and 35 years, respectively. Women predominated among PKT and men in the other groups. In all groups, cyclosporine was the calcineurin inhibitor mostly used. Creatinine at 6 months was lower in the living donor groups (1.26 mg/dL PKT and 1.32 mg/dL LDT; P = NS) in relation to the deceased donor group (1.96 mg/dL; P < .05). DDT had the highest rate of DGF: 44% DDT versus 11.5% LDT vs 0% PKT (P < .05). Subclinical rejection was significantly lower among preemptive transplantations: PKT 7.6% versus LDT 18.5% versus DDT 24% (P < .05). IF/TA was higher in transplants from deceased donors: PKT 11.1%; LDT 11.5%; DDT 32%.

CONCLUSIONS

Preemptive kidney transplantation offered the advantages of a lower creatinine, no DGF, as well as a reduced incidence of subclinical rejection and chronic allograft nephropathy at 6 months posttransplantation.

Hypothesis: it is time to reconsider phenotypes in hypertension

The study of genes and mechanisms associated with hypertension is hampered by the heterogeneity of hypertensive patients. Refining the definition of hypertension is a potential means of improving the clarity of mechanistic studies, but the lack of intermediate phenotypes hinders the assessment of causal relationships. Looking at younger individuals and hemodynamic subsets of hypertension is one such refinement. The authors argue that the separate analysis of patients with isolated diastolic hypertension, predominantly diastolic hypertension, and isolated systolic hypertension in the young in combination with common biomarkers may be an initial step to decrease heterogeneity within patient subsets, thus providing new avenues for genetic and pathophysiological studies.

Emergence of interventional nephrology at the international level

The development of nephrology has been greatly influenced by the performance of procedures. For example, kidney biopsies have elicited substantial knowledge, thereby linking kidney afflictions with their respective histopathologies, which consequently governed the course of therapy. Further, the growth of nephrology has been marked by the implementations of advanced forms of renal replacement therapy. Moreover, there is now the acute acknowledgement that the success of any modality of renal replacement therapy is contingent upon the integrity of its associated peritoneal or vascular access. Consequently, the concept of nephrologist as interventionalist has garnered broad appeal. In fact, the American Society of Diagnostic and Interventional Nephrology and the International Society of Nephrology promote this concept. Notably, these groups have already demonstrated successful outreach programs that have been replicated at local, regional, and national levels throughout the globe.

Reproducibility of ambulatory blood pressure monitoring in hemodialysis patients

Ambulatory blood pressure monitoring (ABPM) has been increasingly used in hemodialysis (HD) practice and research; however, no study has evaluated the reproducibility of ABPM in this population. To address this question, we performed 48-hour interdialytic ABPM on 21 HD patients (mean age, 53 +/- 16 years; 7 women) on two different occasions 68 +/- 34 days (range, 30 to 154 days) apart. To qualify for the protocol, patients had to be at the same dry weight and on the same vasoactive drug regimen at both monitoring periods. BP was analyzed according to three different methods: isolated pre-HD and post-HD values, average pre-HD and post-HD values for the five HD sessions surrounding each monitoring period, and 48-hour interdialytic ABPM. Reproducibility was determined by analysis of the SD of the differences (SDD) between the two monitoring periods and the coefficient of variation of each method of BP determination. Our results show better reproducibility of ABPM (SDD, 10.6/6.6 mm Hg; coefficient of variation, 7.5%/8.1%) compared with isolated pre-HD BP (SDD, 24.4/11.3 mm Hg; coefficient of variation, 16.7%/14.1%) or post-HD BP (SDD, 16.8/14.5 mm Hg; coefficient of variation, 11.7%/17.8%), and averaged pre-HD BP (SDD, 14.7/7.2 mm Hg; coefficient of variation, 10.1%/9.1%) or post-HD BP (SDD, 12.4/8.7 mm Hg; coefficient of variation, 8.9%/11.1%). The reproducibility of the decrease in BP during sleep was poor, with up to 43% of the subjects changing dipping category within or between interdialytic periods. We conclude that ABPM is the most accurate method to study BP in HD patients over time. However, variability is significant, and there is poor reproducibility of the nocturnal decline in BP.

Extreme hyperphosphatemia and acute renal failure after a phosphorus-containing bowel regimen

Phosphate intoxication, manifested by hypocalcemic tetany and acute renal failure, may complicate bowel-cleansing preparations which contain phosphate. These preparations are commonly used to prepare patients for various gastrointestinal procedures. Often, patients who receive these regimens are at increased risk of phosphate intoxication from diseases which slow gastrointestinal transit or decrease renal excretion (renal insufficiency). We present a patient who developed oliguric acute renal failure from severe phosphate intoxication associated with a phosphate-containing bowel-cleansing regimen.

KCNA10: a novel ion channel functionally related to both voltage-gated potassium and CNG cation channels

Our laboratory previously cloned a novel rabbit gene (Kcn1), expressed in kidney, heart, and aorta, and predicted to encode a protein with 58% amino acid identity with the K channel Shaker Kv1.3 (Yao X et al. Proc Natl Acad Sci USA 92: 11711-11715, 1995). Because Kcn1 did not express well (peak current in Xenopus laevis oocytes of 0.3 microA at +60 mV), the human homolog (KCNA10) was isolated, and its expression was optimized in oocytes. KCNA10 mediates voltage-gated K(+) currents that exhibit minimal steady-state inactivation. Ensemble currents of 5-10 microA at +40 mV were consistently recorded from injected oocytes. Channels are closed at the holding potential of -80 mV but are progressively activated by depolarizations more positive than -30 mV, with half-activation at +3.5 +/- 2.5 mV. The channel displays an unusual inhibitor profile because, in addition to being blocked by classical K channel blockers (barium tetraethylammonium and 4-aminopyridine), it is also sensitive to inhibitors of cyclic nucleotide-gated (CNG) cation channels (verapamil and pimozide). Tail-current analysis shows a reversal potential shift of 47 mV/decade change in K concentration, indicating a K-to-Na selectivity ratio of at least 15:1. The phorbol ester phorbol 12-myristate 13-acetate, an activator of protein kinase C, inhibited whole cell current by 42%. Analysis of single-channel currents reveals a conductance of approximately 11 pS. We conclude KCNA10 is a novel human voltage-gated K channel with features common to both K-selective and CNG cation channels. Given its distribution in renal blood vessels and heart, we speculate that KCNA10 may be involved in regulating the tone of renal vascular smooth muscle and may also participate in the cardiac action potential.

[Blood pressure regulation by potassium channels]

Potassium channels are transmembrane proteins that allow this ion to diffuse through the plasma membrane. By participating in the generation of membrane potential they regulate intracellular calcium levels and vascular smooth muscle contraction. Voltage-gated and ATP-gated potassium channels have been described in vessel smooth muscle. Minoxidil and diazoxide vasodilate by opening ATP-gated potassium channels. Soon other K-ATP channel openers will be available. It has been suggested that hypoxic vasodilatation and shock are due to excessive activation of potassium channels. Mutations in potassium channels have been implied in the pathogenesis of essential hypertension.

Cloning and localization of a double-pore K channel, KCNK1: exclusive expression in distal nephron segments

The K-selective channel, TOK1, recently identified in yeast, displays the unusual structural feature of having two putative pore regions, in contrast to all previously cloned K channels. Using the TOK1 pore regions as probes, we identified a human kidney cDNA encoding a 337-amino acid protein (hKCNK1) with four transmembrane segments and two pore regions containing the signature sequence of K channels. Amino acid identity to TOK1 is only 15% overall but 40% at the pores. Northern analysis indicates high expression of a 1.9-kb message in brain > kidney >> heart. Nephron segment localization, carried out in rabbit by reverse transcription-polymerase chain reaction, reveals that KCNK1 is expressed in cortical thick ascending limb, connecting tubule, and cortical collecting duct. It was not detected in the proximal tubule, medullary thick ascending limb, distal convoluted tubule, and glomerulus. We conclude that KCNK1 is a unique, double-pore, mammalian K channel, distantly related to the yeast channel TOK1, that is expressed in distal tubule and is a candidate to participate in renal K homeostasis.

Genomic localization of the human gene for KCNA10, a cGMP-activated K channel

Potassium (K) channels are important components of virtually all cells, and they play critical roles in many cellular functions. KCNA10 represents a new class of K channel specifically regulated by cGMP and postulated to mediate the effects of substances that increase intracellular cGMP. Since KCNA10 has the potential to be useful in candidate gene analysis of inherited diseases, the human gene for KCNA10 was characterized. Fluorescence in situ hybridization indicates that human KCNA10 maps to chromosome 1 at p13.1-->p22.1. Finer mapping of the gene was achieved by PCR of a set of CEPH YAC clones that spanned the region of interest. We found that YAC 818b9 contains human KCNA10. These data indicate human KCNA10 maps to 1p13.1 and resides within the genetic interval defined by microsatellite loci D1S2809 and D1S2726. That region of chromosome 1 contains another K channel gene, KCNA3.