Discordance between estimated and measured changes in plasma volume among patients with acute heart failure

Contemporary Perspectives on Congestion in Heart Failure: Bridging Classic Signs with Evolving Diagnostic and Therapeutic Strategies

Congestion represents a defining hallmark of heart failure (HF) leading to increased morbidity and mortality in HF patients. While it was traditionally viewed as a simple and uniform state of volume overload, contemporary understanding has emphasized its complexity, distinguishing between intravascular, interstitial, and tissue congestion. Congestion contributes to overt clinical manifestation of HF. However, subclinical congestion often goes undetected, increasing the risk of adverse outcomes. Residual congestion, in particular, remains a frequent and challenging issue, with its persistence at discharge being strongly linked to rehospitalization and poor prognosis. Clinical evaluation often fails to reliably identify the resolution of congestion, highlighting the need for supplementary diagnostic methods. Improvement in imaging modalities, including lung ultrasound, venous Doppler, and echocardiography, have significantly enhanced the detection of congestion. Moreover, biomarkers such as natriuretic peptides, bioactive adrenomedullin, soluble CD146, and carbohydrate antigen 125 offer valuable, complementary insights into fluid distribution and the severity of HF congestion. Therefore, a comprehensive, multimodal strategy that integrates clinical evaluation with imaging and biomarker data is crucial for optimizing the management of congestion in HF. Future approaches should prioritize personalized decongestive therapy, addressing both intravascular and tissue congestion, while aiming to preserve renal function and limit neurohormonal activation. Refinement of these strategies holds promise for improving long-term outcomes, reducing rehospitalizations, and enhancing overall patient prognosis.

The Role of the Estimated Plasma Volume Variation in Assessing Decongestion in Patients with Acute Decompensated Heart Failure

INTRODUCTION AND AIM

Assessing decongestion in patients with acute decompensated heart failure (ADHF) is challenging, requiring multiple parameters and often remaining imprecise. The study aimed to investigate the utility of indirectly estimating plasma variation (∆ePVS) for evaluating decongestion in ADHF patients in relation to natriuretic peptides.

MATERIALS AND METHODS

This prospective, observational, single-center study included 111 patients (mean age 74 years, 40% female) hospitalized with ADHF and treated with intravenous diuretics along with optimized medical therapy. Patients were clinically and echocardiographically evaluated at admission, with blood tests performed at both admission and discharge. A decrease of ≥30% in NT-proBNP at discharge was considered a marker of decongestion. ∆ePVS was calculated using the Strauss formula: ∆ePVS (%) = 100 × [(Hb admission/Hb discharge) × (1 - Hct discharge)/(1 - Hct admission)] - 100. A negative ∆ePVS (<0%) at discharge was considered a marker of hemoconcentration. Patients were divided into two groups: G1 (∆ePVS < 0%, 81 patients) and G2 (∆ePVS ≥ 0%, 30 patients).

RESULTS

Both groups had similar left ventricular ejection fraction (LVEF) values of 46%, mean hemoglobin (Hb) (12 g/dL), and creatinine (1.16 ± 0.65 mg/dL). NT-proBNP decreased in 88% patients in G1 and in 26% patients in G2 (p < 0.001). During hospitalization, five patients from G2 died. At 6 months, rehospitalization occurred in 35% of G2 and 21% of G1 (p = 0.04), with mortality rates of 37% in G2 and 11% in G1 (p = 0.012). Multivariate regression identified ∆ePVS as the only significant predictor of NT-proBNP decrease (OR 0.11, 95% CI 0.04-0.33, p < 0.001).

CONCLUSIONS

Indirect estimation of plasma volume and its variation are valuable, accessible, and cost-effective parameters for assessing decongestive treatment in ADHF patients, complementing natriuretic peptides.

Optimization of Kidney Health in Liver Transplant Candidates: Pretransplant Considerations and Modalities

Patients with decompensated end-stage liver disease (ESLD) are at increased risk for mortality, and only liver transplantation (LT) offers meaningful hope for survival. These patients are at risk for kidney dysfunction through the continuum of care for ESLD including LT. We discuss the role of accurate estimation and measurement of baseline glomerular filtration rate in assessment of kidney dysfunction among those with ESLD. Optimizing kidney function is a vital goal in the management of these patients before LT. In this review, we summarize salient aspects of assessing and optimizing kidney function in this patient population. Precipitating factors and different causes of acute kidney injury are discussed, including hepatorenal syndrome. We further review treatment options for acute kidney injury including volume management. The role of vasopressor therapy, renal replacement therapy, and transjugular intrahepatic portosystemic shunting are discussed.

Relative Blood Volume Profiles Hours After Loop Diuretic Administration: A Systematic Review and Meta-analysis

Background

Plasma refill rates can be estimated by combining measurements of urine output with relative blood volume profiles. Change in plasma refill rates could guide decongestive loop diuretic therapy in acute heart failure. The objective of the study was to assess average relative blood volume profiles generated from 2 or 3 follow-up measurements obtained hours after loop diuretic administration in subjects with vs without baseline congestion.

Methods

A systematic review was conducted of articles written in English, French, Spanish, and German, using MEDLINE (1964 to 2019), Cochrane Reviews (1996 to 2019), and Embase (1974 to 2019). Search terms included the following: diuretics, hemoconcentration, plasma volume, and blood volume. We included studies of adults given a loop diuretic with at least one baseline and one follow-up measurement. A single author extracted subject- or group-level blood volume measurements, aggregated them when needed, and converted them to relative changes.

Results

Across all 16 studies that met the prespecified inclusion criteria, relative blood volume maximally decreased 9.2% (6.6% to 12.0%) and returned to baseline after 3 or more hours. Compared to subjects without congestion, those with congestion experienced smaller decreases in relative blood volume across all follow-up periods (P = 0.001) and returned to baseline within the final follow-up period.

Conclusions

Single doses of loop diuretics produce measurable changes in relative blood volume that follow distinct profiles for subjects with vs without congestion. Measured alongside urine output, these profiles may be used to estimate plasma refill rates-potential patient-specific targets for decongestive therapy across serial diuretic doses.

Critical Analysis of the Effects of SGLT2 Inhibitors on Renal Tubular Sodium, Water and Chloride Homeostasis and Their Role in Influencing Heart Failure Outcomes

SGLT2 (sodium-glucose cotransporter 2) inhibitors interfere with the reabsorption of glucose and sodium in the early proximal renal tubule, but the magnitude and duration of any ensuing natriuretic or diuretic effect are the result of an interplay between the degree of upregulation of SGLT2 and sodium-hydrogen exchanger 3, the extent to which downstream compensatory tubular mechanisms are activated, and (potentially) the volume set point in individual patients. A comprehensive review and synthesis of available studies reveals several renal response patterns with substantial variation across studies and clinical settings. However, the common observation is an absence of a large acute or chronic diuresis or natriuresis with these agents, either when given alone or combined with other diuretics. This limited response results from the fact that renal compensation to these drugs is rapid and nearly complete within a few days or weeks, preventing progressive volume losses. Nevertheless, the finding that fractional excretion of glucose and lithium (the latter being a marker of proximal sodium reabsorption) persists during long-term treatment with SGLT2 inhibitors indicates that pharmacological tolerance to the effects of these drugs at the level of the proximal tubule does not meaningfully occur. This persistent proximal tubular effect of SGLT2 inhibitors can be hypothesized to produce a durable improvement in the internal set point for volume homeostasis, which may become clinically important during times of fluid expansion. However, it is difficult to know whether a treatment-related change in the volume set point actually occurs or contributes to the effect of these drugs to reduce the risk of major heart failure events. SGLT2 inhibitors exert cardioprotective effects by a direct effect on cardiomyocytes that is independent of the presence of or binding to SGLT2 or the actions of these drugs on the proximal renal tubule. Nevertheless, changes in the volume set point mediated by SGLT2 inhibitors might potentially act cooperatively with the direct favorable molecular and cellular effects of these drugs on cardiomyocytes to mediate their benefits on the development and clinical course of heart failure.