Serial direct sodium removal in patients with heart failure and diuretic resistance.

AIMS: Loop diuretics may exacerbate cardiorenal syndrome (CRS) in heart failure (HF). Direct sodium removal (DSR) using the peritoneal membrane, in conjunction with complete diuretic withdrawal, may improve CRS and diuretic resistance. METHODS AND RESULTS: Patients with HF requiring high-dose loop diuretics were enrolled in two prospective, single-arm studies: RED DESERT (n = 8 euvolaemic patients), and SAHARA (n = 10 hypervolaemic patients). Loop diuretics were withdrawn, and serial DSR was utilized to achieve and maintain euvolaemia. At baseline, participants required a median 240 mg (interquartile range [IQR] 200-400) oral furosemide equivalents/day, which was withdrawn in all participants during DSR (median time of DSR 4 weeks [IQR 4-6]). Diuretic response (queried by formal 40 mg intravenous furosemide challenge and 6 h urine sodium quantification) increased substantially from baseline (81 ± 37 mmol) to end of DSR (223 ± 71 mmol, p < 0.001). Median time to re-initiate diuretics was 87 days, and the median re-initiation dose was 8% (IQR 6-10%) of baseline. At 1 year, diuretic dose remained substantially below baseline (30 [IQR 7.5-40] mg furosemide equivalents/day). Multiple dimensions of kidney function such as filtration, uraemic toxin excretion, kidney injury, and electrolyte handling improved (p < 0.05 for all). HF-related biomarkers including N-terminal pro-B-type natriuretic peptide, carbohydrate antigen-125, soluble ST2, interleukin-6, and growth differentiation factor-15 (p < 0.003 for all) also improved. CONCLUSIONS: In patients with HF and diuretic resistance, serial DSR therapy with loop diuretic withdrawal was feasible and associated with substantial and persistent improvement in diuretic resistance and several cardiorenal parameters. If replicated in randomized controlled studies, DSR may represent a novel therapy for diuretic resistance and CRS. CLINICAL TRIAL REGISTRATION: RED DESERT (NCT04116034), SAHARA (NCT04882358).

Clinical practice guidelines for diagnostic and treatment of the chronic heart failure.

Chronic heart failure continues to be one of the main causes of impairment in the functioning and quality of life of people who suffer from it, as well as one of the main causes of mortality in our country and around the world. Mexico has a high prevalence of risk factors for developing heart failure, such as high blood pressure, diabetes, and obesity, which makes it essential to have an evidence-based document that provides recommendations to health professionals involved in the diagnosis and treatment of these patients. This document establishes the clinical practice guide (CPG) prepared at the initiative of the Mexican Society of Cardiology (SMC) in collaboration with the Iberic American Agency for the Development and Evaluation of Health Technologies, with the purpose of establishing recommendations based on the best available evidence and agreed upon by an interdisciplinary group of experts. This document complies with international quality standards, such as those described by the US Institute of Medicine (IOM), the National Institute of Clinical Excellence (NICE), the Intercollegiate Network for Scottish Guideline Development (SIGN) and the Guidelines International Network (G-I-N). The Guideline Development Group was integrated in a multi-collaborative and interdisciplinary manner with the support of methodologists with experience in systematic literature reviews and the development of CPG. A modified Delphi panel methodology was developed and conducted to achieve an adequate level of consensus in each of the recommendations contained in this CPG. We hope that this document contributes to better clinical decision making and becomes a reference point for clinicians who manage patients with chronic heart failure in all their clinical stages and in this way, we improve the quality of clinical care, improve their quality of life and reducing its complications.

La insuficiencia cardiaca crónica sigue siendo unas de las principales causas de afectación en el funcionamiento y en la calidad de vida de las personas que la presentan, así como una de las primeras causas de mortalidad en nuestro país y en todo el mundo. México tiene una alta prevalencia de factores de riesgo para desarrollar insuficiencia cardiaca, tales como hipertensión arterial, diabetes y obesidad, lo que hace imprescindible contar con un documento basado en la evidencia que brinde recomendaciones a los profesionales de la salud involucrados en el diagnóstico y el tratamiento de estos pacientes. Este documento establece la guía de práctica clínica (GPC) elaborada por iniciativa de la Sociedad Mexicana de Cardiología (SMC) en colaboración con la Agencia Iberoamericana de Desarrollo y Evaluación de Tecnologías en Salud, con la finalidad de establecer recomendaciones basadas en la mejor evidencia disponible y consensuadas por un grupo interdisciplinario y multicolaborativo de expertos. Cumple con estándares internacionales de calidad, como los descritos por el Institute of Medicine de los Estados Unidos de América (IOM), el National Institute of Clinical Excellence (NICE) del Reino Unido, la Intercollegiate Network for Scottish Guideline Development (SIGN) de Escocia y la Guidelines International Network (G-I-N). El grupo de desarrollo de la guía se integró de manera interdisciplinaria con el apoyo de metodólogos con experiencia en revisiones sistemáticas de la literatura y en el desarrollo de GPC. Se llevó a cabo y se condujo metodología de panel Delphi modificado para lograr un nivel de consenso adecuado en cada una de las recomendaciones contenidas en esta GPC. Esperamos que este documento contribuya para la mejor toma de decisiones clínicas y se convierta en un punto de referencia para los clínicos que manejan pacientes con insuficiencia cardiaca crónica en todas sus etapas clínicas, y de esta manera logremos mejorar la calidad en la atención clínica, aumentar la calidad de vida de los pacientes y disminuir las complicaciones de la enfermedad.

Empagliflozin in Heart Failure: Regional Nephron Sodium Handling Effects.

SIGNIFICANCE STATEMENT: The effect of sodium-glucose cotransporter-2 inhibitors (SGLT2i) on regional tubular sodium handling is poorly understood in humans. In this study, empagliflozin substantially decreased lithium reabsorption in the proximal tubule (PT) (a marker of proximal tubular sodium reabsorption), a magnitude out of proportion to that expected with only inhibition of sodium-glucose cotransporter-2. This finding was not driven by an "osmotic diuretic" effect; however, several parameters changed in a manner consistent with inhibition of the sodium-hydrogen exchanger 3. The large changes in proximal tubular handling were acutely buffered by increased reabsorption in both the loop of Henle and the distal nephron, resulting in the observed modest acute natriuresis with these agents. After 14 days of empagliflozin, natriuresis waned due to increased reabsorption in the PT and/or loop of Henle. These findings confirm in humans that SGLT2i have complex and important effects on renal tubular solute handling. BACKGROUND: The effect of SGLT2i on regional tubular sodium handling is poorly understood in humans but may be important for the cardiorenal benefits. METHODS: This study used a previously reported randomized, placebo-controlled crossover study of empagliflozin 10 mg daily in patients with diabetes and heart failure. Sodium handling in the PT, loop of Henle (loop), and distal nephron was assessed at baseline and day 14 using fractional excretion of lithium (FELi), capturing PT/loop sodium reabsorption. Assessments were made with and without antagonism of sodium reabsorption through the loop using bumetanide. RESULTS: Empagliflozin resulted in a large decrease in sodium reabsorption in the PT (increase in FELi=7.5%±10.6%, P = 0.001), with several observations suggesting inhibition of PT sodium hydrogen exchanger 3. In the absence of renal compensation, this would be expected to result in approximately 40 g of sodium excretion/24 hours with normal kidney function. However, rapid tubular compensation occurred with increased sodium reabsorption both in the loop ( P < 0.001) and distal nephron ( P < 0.001). Inhibition of sodium-glucose cotransporter-2 did not attenuate over 14 days of empagliflozin ( P = 0.14). However, there were significant reductions in FELi ( P = 0.009), fractional excretion of sodium ( P = 0.004), and absolute fractional distal sodium reabsorption ( P = 0.036), indicating that chronic adaptation to SGLT2i results primarily from increased reabsorption in the loop and/or PT. CONCLUSIONS: Empagliflozin caused substantial redistribution of intrarenal sodium delivery and reabsorption, providing mechanistic substrate to explain some of the benefits of this class. Importantly, the large increase in sodium exit from the PT was balanced by distal compensation, consistent with SGLT2i excellent safety profile. CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER: ClinicalTrials.gov ( NCT03027960 ).

Effect on Kidney Function Recovery Guiding Decongestion with VExUS in Patients with Cardiorenal Syndrome 1: A Randomized Control Trial.

INTRODUCTION: In cardiorenal syndrome type 1 (CRS1), vascular congestion is central to the pathophysiology of heart failure and thus a key target for management. The venous evaluation by ultrasound (VExUS) system could guide decongestion effectively and thereby improve outcomes. METHODS: In this randomized clinical trial, patients with CRS1 (i.e., increase in creatinine ≥0.3 mg/dL) were randomized to guide decongestion with VExUS compared to usual clinical evaluation. The primary endpoint was to assess kidney function recovery (KFR), and the key secondary endpoint was decongestion evaluated by physical examination and changes in brain natriuretic peptide (BNP) and CA-125. Exploratory endpoints included days of hospitalization and mortality. RESULTS: From March 2022 to February 2023, a total of 140 patients were randomized 1:1 (70 in the VExUS and 70 in the control group). KFR was not statistically different between groups. However, VExUS improved more than twice the odds to achieve decongestion (odds ratio [OR]: 2.6, 95% CI: 1.9-3.0, p = 0.01) and the odds to reach a decrease of BNP >30% (OR: 2.4, 95% CI: 1.3-4.1, p = 0.01). The survival at 90 days, recongestion, and CA-125 were similar between groups. CONCLUSION: In patients with CRS1, we observed that VExUS-guided decongestion did not improve the probability of KFR but improved the odds to achieve decongestion.

Association of Urine Galectin-3 With Cardiorenal Outcomes in Patients With Heart Failure.

BACKGROUND AND OBJECTIVES: Approaches to distinguishing pathological cardiorenal dysfunction in heart failure (HF) from functional/hemodynamically mediated changes in serum creatinine are needed. We investigated urine galectin-3 as a candidate biomarker of renal fibrosis and a prognostic indicator of cardiorenal dysfunction phenotypes. METHODS: We measured urine galectin-3 in 2 contemporary HF cohorts: the Yale Transitional Care Clinic (YTCC) cohort (n = 132) and the Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist (TOPCAT) trial (n = 434). We assessed the association of urine galectin-3 with all-cause mortality in both cohorts and the association with an established marker of renal tissue fibrosis, urinary amino-terminal propeptide of type III procollagen (PIIINP) in TOPCAT. RESULTS: In the YTCC cohort, there was significant effect modification between higher urine galectin-3 and lower estimated glomerular filtration rates (eGFRs) (Pinteraction = 0.046), such that low eGFR levels had minimal prognostic importance if urine galectin-3 levels were low, but they were important and indicated high risk if urine galectin-3 levels were high. Similar observations were noted in the TOPCAT study (Pinteraction = 0.002). In TOPCAT, urine galectin-3 also positively correlated with urine PIIINP at both baseline (r = 0.43; P < 0.001) and at 12 months (r = 0.42; P < 0.001). CONCLUSIONS: Urine galectin-3 levels correlated with an established biomarker of renal fibrosis in 2 cohorts and was able to differentiate high- vs low-risk phenotypes of chronic kidney disease in HF. These proof-of-concept results indicate that additional biomarker research to differentiate cardiorenal phenotypes is warranted.

Randomized controlled trial of urinE chemiStry guided aCute heArt faiLure treATmEnt (ESCALATE): Rationale and design.

Diuresis to achieve decongestion is a central aim of therapy in patients hospitalized for acute decompensated heart failure (ADHF). While multiple clinical trials have investigated initial diuretic strategies for a designated period of time, there is a paucity of evidence to guide diuretic titration strategies continued until decongestion is achieved. The use of urine chemistries (urine sodium and creatinine) in a natriuretic response prediction equation accurately estimates natriuresis in response to diuretic dosing, but a randomized clinical trial is needed to compare a urine chemistry-guided diuresis strategy with a strategy of usual care. The urinE chemiStry guided aCute heArt faiLure treATmEnt (ESCALATE) trial is designed to test the hypothesis that protocolized diuretic therapy guided by spot urine chemistry through completion of intravenous diuresis will be superior to usual care and improve outcomes over the 14 days following randomization. ESCALATE will randomize and obtain complete data on 450 patients with acute heart failure to a diuretic strategy guided by urine chemistry or a usual care strategy. Key inclusion criteria include an objective measure of hypervolemia with at least 10 pounds of estimated excess volume, and key exclusion criteria include significant valvular stenosis, hypotension, and a chronic need for dialysis. Our primary outcome is days of benefit over the 14 days after randomization. Days of benefit combines patient symptoms captured by global clinical status with clinical state quantifying the need for hospitalization and intravenous diuresis. CLINICAL TRIAL REGISTRATION: NCT04481919.

The importance of forward flow and venous congestion in diuretic response in acute heart failure: Insights from the ESCAPE trial.

AIMS: Previous studies have suggested venous congestion as a stronger mediator of negative cardio-renal interactions than low cardiac output, with neither factor having a dominant role. While the influence of these parameters on glomerular filtration have been described, the impact on diuretic responsiveness is unclear. The goal of this analysis was to understand the hemodynamic correlates of diuretic response in hospitalized patients with heart failure. METHODS AND RESULTS: We analyzed patients from the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness (ESCAPE) dataset. Diuretic efficiency (DE) was defined as the average daily net fluid output per doubling of the peak loop diuretic dose. We evaluated a pulmonary artery catheter hemodynamic-guided cohort (n = 190) and a transthoracic echocardiogram (TTE) cohort (n = 324) where DE was evaluated with hemodynamic and TTE parameters. Metrics of "forward flow" such as cardiac index, mean arterial pressure and left ventricular ejection fraction were not associated with DE (p > 0.2 for all). Worse baseline venous congestion was paradoxically associated with better DE as assessed by right atrial pressure (RAP), right atrial area (RAA), and right ventricular systolic and diastolic area (p < 0.05 for all). Renal perfusion pressure (capturing both congestion and forward flow) was not associated with diuretic response (p = 0.84). CONCLUSIONS: Worse venous congestion was weakly associated with better loop diuretic response. Metrics of "forward flow" did not demonstrate any correlation with diuretic response. These observations raise questions about the concept of central hemodynamic perturbations as the primary drivers of diuretic resistance on a population level in HF.

In-Hospital Observation on Oral Diuretics After Treatment for Acute Decompensated Heart Failure: Evaluating the Utility.

BACKGROUND: Following treatment for acute decompensated heart failure, in-hospital observation on oral diuretics (OOD) is recommended, assuming it provides actionable information on discharge diuretic dosing and thus reduces readmissions. METHODS: In the Mechanisms of Diuretic Resistance (MDR) cohort, we analyzed in-hospital measures of diuretic response, provider's decisions, and diuretic response ≈30 days postdischarge. In a Yale multicenter cohort, we assessed if in-hospital OOD was associated with 30-day readmission risk. The main objective of this study was to evaluate the utility of in-hospital OOD. RESULTS: Of the 468 patients in the MDR cohort, 57% (N=265) underwent in-hospital OOD. During the OOD, weight change and net fluid balance correlated poorly with each other (r=0.36). Discharge diuretic dosing was similar between patients who had increased, stable, or decreased weight (decreased discharge dose from OOD dose in 77% versus 72% versus 70%, respectively), net fluid status (decreased discharge dose from OOD dose in 100% versus 69% versus 74%, respectively), and urine output (decreased discharge dose from OOD dose in 69% versus 79% versus 72%, respectively) during the 24-hour OOD period (P>0.27 for all). In participants returning at 30 days for formal quantification of outpatient diuretic response (n=98), outpatient and inpatient OOD natriuresis was poorly correlated (r=0.26). In the Yale multicenter cohort (n=18 454 hospitalizations), OOD occurred in 55% and was not associated with 30-day hospital readmission (hazard ratio, 0.98 [95% CI, 0.93-1.05]; P=0.51). CONCLUSIONS: In-hospital OOD did not provide actionable information on diuretic response, was not associated with outpatient dose selection, did not predict subsequent outpatient diuretic response, and was not associated with lower readmission rate. Additional research is needed to replicate these findings and understand if these resources could be better allocated elsewhere. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT02546583.

Improvement in Renal Function During the Treatment of Acute Decompensated Heart Failure: Relationship With Markers of Renal Tubular Injury and Prognostic Importance.

BACKGROUND: Improvement in renal function (IRF) in acute decompensated heart failure is associated with adverse outcomes. The mechanisms driving this paradox remain undefined. METHODS: Using the ROSE-AHF study (Renal Optimization Strategies Evaluation-Acute Heart Failure), 277 patients were grouped according to renal function, with IRF defined by a ≥20% increase (N=75), worsening renal function by a ≥20% decline (N=53), and stable renal function (SRF) by a <20% change (N=149) in estimated glomerular filtration rate between baseline and 72 hours. Three well-validated renal tubular injury markers, NGAL (neutrophil gelatinase-associated lipocalin), NAG (N-acetyl-ß-d-glucosaminidase), and KIM-1 (kidney injury molecule 1), were evaluated at baseline and 72 hours. Patients were also classified by the pattern of change in these markers. RESULTS: Patients with IRF had the lowest admission estimated glomerular filtration rate (IRF, 37 [28 to 51] mL/min per 1.73 m2; worsening renal function, 43 [35 to 55] mL/min per 1.73 m2; and SRF, 43 [32 to 55] mL/min per 1.73 m2; Ptrend=0.032) but greater cumulative urine output (IRF, 8780 [7025 to 11 208] mL; worsening renal function, 7860 [5555 to 9765] mL; and SRF, 8150 [6325 to 10 456] mL; Ptrend=0.024) and weight loss (IRF, -9.0 [-12.4 to -5.3] lb; worsening renal function, -5.1 [-8.1 to -1.3] lb; and SRF, -7.1 [-11.9 to -3.2] lb; Ptrend<0.001) despite similar diuretic doses (Ptrend=0.16). There were no differences in the relative change in NGAL, NAG, or KIM-1 between renal function groups (Ptrend>0.19 for all). Patients with IRF had worse survival than patients with SRF (27% versus 54%; hazard ratio, 1.98 [1.10-3.58]; P=0.024). CONCLUSIONS: IRF during decongestive therapy for acute decompensated heart failure was not associated with improved markers of renal tubular injury and was associated with worsened survival, likely driven by the presence of greater underlying cardiorenal dysfunction and more severe congestion.

Changes in the Inferior Vena Cava Are More Sensitive Than Venous Pressure During Fluid Removal: A Proof-of-Concept Study.

BACKGROUND: Congestion is central to the pathophysiology of heart failure (HF); thus, tracking congestion is crucial for the management of patients with HF. In this study we aimed to compare changes in inferior vena cava diameter (IVCD) with venous pressure following manipulation of volume status during ultrafiltration in patients with cardiac dysfunction. METHODS AND RESULTS: Patients with stable hemodialysis and with systolic or diastolic dysfunction were studied. Central venous pressure (CVP) and peripheral venous pressure (PVP) were measured before and after hemodialysis. IVCD and PVP were measured simultaneously just before dialysis, 3 times during dialysis and immediately after dialysis. Changes in IVCD and PVP were compared at each timepoint with ultrafiltration volumes. We analyzed 30 hemodialysis sessions from 20 patients. PVP was validated as a surrogate for CVP. Mean ultrafiltration volume was 2102 ± 667 mL. IVCD discriminated better ultrafiltration volumes ≤ 500 mL or ≤ 750 mL than PVP (AUC 0.80 vs 0.62, and 0.80 vs 0.56, respectively; both P< 0.01). IVCD appeared to track better ultrafiltration volume (P< 0.01) and hemoconcentration (P< 0.05) than PVP. Changes in IVCD were of greater magnitude than those of PVP (average change from predialysis: -58 ± 30% vs -28 ± 21%; P< 0.001). CONCLUSIONS: In patients undergoing ultrafiltration, changes in IVCD tracked changes in volume status better than venous pressure.

Sodium restriction in patients with chronic heart failure and reduced ejection fraction: A randomized controlled trial.

BACKGROUND: Sodium restriction is recommended for patients with heart failure (HF) despite the lack of solid clinical evidence from randomized controlled trials. Whether or not sodium restrictions provide beneficial cardiac effects is not known. METHODS: The present study is a randomized, double-blind, controlled trial of stable HF patients with ejection fraction ≤ 40%. Patients were allocated to sodium restriction (2 g of sodium/day) vs. control (3 g of sodium/day). The primary outcome was change in N-terminal pro-B-type natriuretic peptide (NT-proBNP) at 20 weeks. Secondary outcomes included quality of life and adverse safety events (HF readmission, blood pressure or electrolyte abnormalities). RESULTS: Seventy patients were enrolled. Median baseline sodium consumption was 3268 (2225-4537) mg/day. Adherence to the intervention based on 24-hour urinary sodium was 32%. NT-proBNP and quality of life did not significantly change between groups (p > 0.05 for both). Adverse safety events were not significantly different between the arms (p > 0.6 for all). In the per protocol analysis, patients who achieved a sodium intake < 2500 mg/day at the intervention conclusion showed improvements in NT-proBNP levels (between-group difference: -55%, 95% confidence interval -27 to -73%; p = 0.002) and quality of life (between-group difference: -11 ± 5 points; p = 0.04). Blood pressure decreased in patients with lower sodium intake (between-group difference: -9 ± 5 mmHg; p = 0.05) without significant differences in symptomatic hypotension or other safety events (p > 0.3 for all). CONCLUSIONS: Adherence assessed by 24-hour natriuresis and by the nutritionist was poor. The group allocated to sodium restriction did not show improvement in NT-proBNP. However, patients who achieved a sodium intake < 2500 mg/day appeared to have improvements in NT-proBNP and quality of life without any adverse safety signals. CLINICALTRIALS: gov Identifier: NCT03351283.

Risk stratification of patients listed for heart transplantation while supported with extracorporeal membrane oxygenation.

OBJECTIVES: Extracorporeal membrane oxygenation (ECMO) is used to support patients in severe cardiogenic shock. In the absence of recovery, these patients may need to be listed for heart transplant (HT), which offers the best long-term prognosis. However, posttransplantation mortality is significantly elevated in patients who receive ECMO. The objective of the present study was to describe and risk-stratify different profiles of patients listed for HT supported by ECMO. METHODS: Patients listed for HT in the United Network for Organ Sharing database were analyzed. The primary outcome was 1-year survival and was assessed in patients bridged to transplant with ECMO (ECMOBTT) and patients who were previously supported on ECMO but had it removed before HT (ECMOREMOVED). RESULTS: Among 65,636 adult candidates listed for HT (between 2001 and 2017), 712 were supported on ECMO, 292 of whom (41%) underwent HT (ECMOBTT, n = 202; ECMOREMOVED, n = 90). Most of the patients with ECMOREMOVED were transplanted with a ventricular assist device. In ECMOBTT, recipient age (each 10-year increase), time on the waitlist (both defined as minor risk factors), need for dialysis, and need for mechanical ventilation (both defined as major risk factors) were independent predictors of mortality. ECMOREMOVED and ECMOBTT with no risk factors showed 1-year survival comparable to that in patients who were never supported on ECMO. Compared with patients who were never on ECMO, patients in ECMOBTT group with minor risk factors, 1 major risk factor, and 2 major risk factors had ~2-, ~5-, and >10-fold greater 1-year mortality, respectively (P < .05). CONCLUSIONS: The HT recipients in the ECMOREMOVED and ECMOBTT groups with no risk factors showed similar survival as the HT recipients who were never supported on ECMO. In the ECMOBTT group, posttransplantation mortality increased significantly with increasing risk factors.

Hemoconcentration of Creatinine Minimally Contributes to Changes in Creatinine during the Treatment of Decompensated Heart Failure.

Background: Worsening serum creatinine is common during treatment of acute decompensated heart failure (ADHF). A possible contributor to creatinine increase is diuresis-induced changes in volume of distribution (VD) of creatinine as total body water (TBW) contracts around a fixed mass of creatinine. Our objective was to better understand the filtration and nonfiltration factors driving change in creatinine during ADHF. Methods: Participants in the ROSE-AHF trial with baseline to 72-hour serum creatinine; net fluid output; and urinary KIM-1, NGAL, and NAG were included (n=270). Changes in VD were calculated by accounting for measured input and outputs from weight-based calculated TBW. Changes in observed creatinine (Crobserved) were compared with predicted changes in creatinine after accounting for alterations in VD and non-steady state conditions using a kinetic GFR equation (Cr72HR Kinetic). Results: When considering only change in VD, the median diuresis to elicit a ≥0.3 mg/dl rise in creatinine was -7526 ml (IQR, -5932 to -9149). After accounting for stable creatinine filtration during diuresis, a change in VD alone was insufficient to elicit a ≥0.3 mg/dl rise in creatinine. Larger estimated decreases in VD were paradoxically associated with improvement in Crobserved (r=-0.18, P=0.003). Overall, -3% of the change in eCr72HR Kinetic was attributable to the change in VD. A ≥0.3 mg/dl rise in eCr72HR Kinetic was not associated with worsening of KIM-1, NGAL, NAG, or postdischarge survival (P>0.05 for all). Conclusions: During ADHF therapy, increases in serum creatinine are driven predominantly by changes in filtration, with minimal contribution from change in VD.

Renin-Angiotensin-Aldosterone System Activation and Diuretic Response in Ambulatory Patients With Heart Failure.

Rationale & Objective: Heart failure treatment relies on loop diuretics to induce natriuresis and decongestion, but the therapy is often limited by diuretic resistance. We explored the association of renin-angiotensin-aldosterone system (RAAS) activation with diuretic response. Study Design: Observational cohort. Setting & Population: Euvolemic ambulatory adults with chronic heart failure were administered torsemide in a monitored environment. Predictors: Plasma total renin, active renin, angiotensinogen, and aldosterone levels. Urine total renin and angiotensinogen levels. Outcomes: Sodium output per doubling of diuretic dose and fractional excretion of sodium per doubling of diuretic dose. Analytical Approach: Robust linear regression models estimated the associations of each RAAS intermediate with outcomes. Results: The analysis included 56 participants, and the median age was 65 years; 50% were women, and 41% were Black. The median home diuretic dose was 80-mg furosemide equivalents. In unadjusted and multivariable-adjusted models, higher levels of RAAS measures were generally associated with lower diuretic efficiency. Higher plasma total renin remained significantly associated with lower sodium output per doubling of diuretic dose (ß = -0.41 [-0.76, -0.059] per SD change) with adjustment; higher plasma total and active renin were significantly associated with lower fractional excretion of sodium per doubling of diuretic dose (ß = -0.48 [-0.83, -0.14] and ß = -0.51 [-0.95, -0.08], respectively) in adjusted models. Stratification by RAAS inhibitor use did not substantially alter these associations. Limitations: Small sample size; highly selected participants; associations may not be causal. Conclusions: Among multiple measures of RAAS activation, higher plasma total and active renin levels were consistently associated with lower diuretic response. These findings highlight the potential drivers of diuretic resistance and underscore the need for high-quality trials of decongestive therapy enhanced by RAAS blockade.

Tricuspid and mitral remodelling in atrial fibrillation: a three-dimensional echocardiographic study.

AIMS: Atrial fibrillation (AF) is associated with atrial enlargement, mitral annulus (MA) and tricuspid annulus (TA) dilation, and atrial functional regurgitation (AFR). However, less is known about the impact of AF on both atrioventricular valves in those with normal and abnormal ventricular function. We aimed to compare the remodelling of the TA and MA in patients with non-valvular AF without significant AFR. METHODS AND RESULTS: Ninety-two patients referred for transoesophageal echocardiography were included and categorized into three groups: (i) AF with normal left ventricular (LV) function (Normal LV-AF), n = 36; (ii) AF with LV systolic dysfunction (LVSD-AF), n = 29; and (iii) Controls in sinus rhythm, n = 27. Three-dimensional MA and TA geometry were analysed using automated software. In patients with AF regardless of LV function, the MA and TA areas were larger compared with controls (LVSD-AF vs. Normal LV-AF vs. Controls, end-systolic MA: 5.2 ± 1.1 vs. 4.5 ± 0.7 vs. 3.9 ± 0.7 cm2/m2; end-systolic TA: 5.6 ± 1.3 vs. 5.3 ± 1.3 vs. 4.1 ± 0.7 cm2/m2; P < 0.05 for each comparison with Controls). TA and MA areas were not statistically different between the two AF groups. The TA increase over controls was greater than that of the MA in the Normal LV-AF group (27.7% vs. 15.6%, P = 0.041). Conversely, in the LVSD-AF group, MA and TA increased similarly (35.9% vs. 32.4%, P = 0.660). CONCLUSION: Patients with AF showed dilation of both TA and MA compared with patients in sinus rhythm. In patients with normal LV function, AF was associated with greater TA dilation than MA dilation whereas in patients with LVSD the TA and MA were equally dilated.

Changes in inferior vena cava area represent a more sensitive metric than changes in filling pressures during experimental manipulation of intravascular volume and tone.

AIMS: Remote monitoring of pulmonary artery pressure has reduced heart failure (HF) hospitalizations in chronic HF as elevation of pulmonary artery pressure provides information that can guide treatment. The venous system is characterized by high capacitance, thus substantial increases in intravascular volume can occur before filling pressures increase. The inferior vena cava (IVC) is a highly compliant venous conduit and thus a candidate for early detection of change in intravascular volume. We aimed to compare IVC cross-sectional area using a novel sensor with cardiac filling pressures during experimental manipulation of volume status, vascular tone, and cardiac function. METHODS AND RESULTS: Experiments were conducted in sheep to manipulate volume status (colloid infusion), vascular tone (nitroglycerin infusion) and cardiac function (rapid cardiac pacing). A wireless implantable IVC sensor was validated ex-vivo and in-vivo, and then used to measure the cross-sectional area of the IVC. Right- and left-sided cardiac filling pressures were obtained via right heart catheterization. The IVC sensor provided highly accurate and precise measurements of cross-sectional area in ex-vivo and in-vivo validation. IVC area changes were more sensitive than the corresponding changes in cardiac filling pressures during colloid infusion (p < 0.001), vasodilatation (p < 0.001) and cardiac dysfunction induced by rapid pacing (p ≤ 0.02). CONCLUSIONS: Inferior vena cava area can be remotely and accurately measured in real time with a wireless implantable sensor. Changes in IVC area are more sensitive than corresponding changes in filling pressures following experimental volume loading and fluid redistribution. Additional research is warranted to understand if remote monitoring of the IVC may have advantages over pressure-based monitors in HF.

How to interpret serum creatinine increases during decongestion.

During decongestion in acute decompensated heart failure (ADHF), it is common to observe elevations in serum creatinine (sCr) values due to vascular congestion, a mechanism that involves increased central venous pressure that has a negative impact on the nephron, promoting greater absorption of water and sodium, increased interstitial pressure in an encapsulated organ developing "renal tamponade" which is one of main physiopathological mechanism associated with impaired kidney function. For the treatment of this syndrome, it is recommended to use diuretics that generate a high urinary output and natriuresis to decongest the venous system, during this process the sCr values can rise, a phenomenon that may bother some cardiologist and nephrologist, since raise the suspicion of kidney damage that could worsen the prognosis of these patients. It is recommended that increases of up to 0.5 mg/dL from baseline are acceptable, but some patients have higher increases, and we believe that an arbitrary number would be impractical for everyone. These increases in sCr may be related to changes in glomerular hemodynamics and true hypovolemia associated with decongestion, but it is unlikely that they are due to structural injury or truly hypoperfusion and may even have a positive connotation if accompanied by an effective decongestion and be associated with a better prognosis in the medium to long term with fewer major cardiovascular and renal events. In this review, we give a comprehensive point of view on the interpretation of creatinine elevation during decongestion in patients with ADHF.

FGF-23 (Fibroblast Growth Factor-23) and Cardiorenal Interactions.

BACKGROUND: Animal models implicate FGF-23 (fibroblast growth factor-23) as a direct contributor to adverse cardiorenal interactions such as sodium avidity, diuretic resistance, and neurohormonal activation, but this has not been conclusively demonstrated in humans. Therefore, we aimed to evaluate whether FGF-23 is associated with parameters of cardiorenal dysfunction in humans with heart failure, independent of confounding factors. METHODS: One hundred ninety-nine outpatients with heart failure undergoing diuretic treatment at the Yale Transitional Care Center were enrolled and underwent blood collection, and urine sampling before and after diuretics. RESULTS: FGF-23 was associated with several metrics of disease severity such as higher home loop diuretic dose and NT-proBNP (N-terminal pro-B-type natriuretic peptide), and lower estimated glomerular filtration rate, serum chloride, and serum albumin. Multivariable analysis demonstrated no statistically significant association between FGF-23 and sodium avidity measured by fractional excretion of sodium, or proximal or distal tubular sodium reabsorption, either before diuretic administration or at peak diuresis (P≥0.11 for all). Likewise, FGF-23 was not independently associated with parameters of diuretic resistance (diuretic excretion, cumulative urine and sodium output, and loop diuretic efficiency [P≥0.33 for all]) or neurohormonal activation (plasma or urine renin [P≥0.36 for all]). Moreover, the upper boundary of the 95% CI of all the partial correlations were ≤0.30, supporting the lack of meaningful correlations. FGF-23 was not associated with mortality in multivariable analysis (P=0.44). CONCLUSIONS: FGF-23 was not meaningfully associated with any cardiorenal parameter in patients with heart failure. While our methods cannot rule out a small effect, FGF-23 is unlikely to be a primary driver of cardiorenal interactions.

Compensatory post-diuretic renal sodium reabsorption is not a dominant mechanism of diuretic resistance in acute heart failure.

AIMS: In healthy volunteers, the kidney deploys compensatory post-diuretic sodium reabsorption (CPDSR) following loop diuretic-induced natriuresis, minimizing sodium excretion and producing a neutral sodium balance. CPDSR is extrapolated to non-euvolemic populations as a diuretic resistance mechanism; however, its importance in acute decompensated heart failure (ADHF) is unknown. METHODS AND RESULTS: Patients with ADHF in the Mechanisms of Diuretic Resistance cohort receiving intravenous loop diuretics (462 administrations in 285 patients) underwent supervised urine collections entailing an immediate pre-diuretic spot urine sample, then 6-h (diuretic-induced natriuresis period) and 18-h (post-diuretic period) urine collections. The average spot urine sodium concentration immediately prior to diuretic administration [median 15 h (13-17) after last diuretic] was 64 ± 33 mmol/L with only 4% of patients having low (<20 mmol/L) urine sodium consistent with CPDSR. Paradoxically, greater 6-h diuretic-induced natriuresis was associated with larger 18-h post-diuretic spontaneous natriuresis (r = 0.7, P < 0.001). Higher pre-diuretic urine sodium to creatinine ratio (r = 0.37, P < 0.001) was the strongest predictor of post-diuretic spontaneous natriuresis. In a subgroup of patients (n = 43) randomized to protocol-driven intensified diuretic therapies, the mean diuretic-induced natriuresis increased three-fold. In contrast to the substantial decrease in spontaneous natriuresis predicted by CPDSR, no change in post-diuretic spontaneous natriuresis was observed (P = 0.47). CONCLUSION: On a population level, CPDSR was not an important driver of diuretic resistance in hypervolemic ADHF. Contrary to CPDSR, a greater diuretic-induced natriuresis predicted a larger post-diuretic spontaneous natriuresis. Basal sodium avidity, rather than diuretic-induced CPDSR, appears to be the predominant determinate of both diuretic-induced and post-diuretic natriuresis in hypervolemic ADHF.