Serum to urinary sodium concentration ratio is an estimate of plasma renin activity in congestive heart failure

Fluid balance in heart failure

Fluid retention is a major determinant of symptoms in patients with heart failure (HF), and it is closely associated with prognosis. Hence, congestion represents a critical therapeutic target in this clinical setting. The first therapeutic strategy in HF patients with fluid overload is optimization of diuretic intervention to maximize water and sodium excretion. When diuretic therapy fails to relieve congestion, renal replacement therapy represents the only alternative option for fluid removal, as well as a way to restore diuretic responsiveness. On this background, the pathophysiology of fluid balance in HF is complex, with heart, kidney, and lung being deeply involved in volume regulation and management. Therefore, the interplay between these organs should be appreciated and considered when fluid overload in HF patients is targeted.

Natriuretic Response Is Highly Variable and Associated With 6-Month Survival: Insights From the ROSE-AHF Trial

OBJECTIVES

This study sought to describe sodium excretion in acute decompensated heart failure (ADHF) clearly and to evaluate the prognostic ability of urinary sodium and fluid-based metrics.

BACKGROUND

Sodium retention drives volume overload, with fluid retention largely a passive, secondary phenomenon. However, parameters (urine output, body weight) used to monitor therapy in ADHF measure fluid rather than sodium balance. Thus, the accuracy of fluid-based metrics hinges on the contested assumption that urinary sodium content is consistent.

METHODS

Patients enrolled in the ROSE-AHF (Renal Optimization Strategies Evaluation-Acute Heart Failure) trial with 24-h sodium excretion available were studied (n = 316). Patients received protocol-driven high-dose loop diuretic therapy.

RESULTS

Sodium excretion through the first 24 h was highly variable (range 0.12 to 19.8 g; median 3.63 g, interquartile range: 1.85 to 6.02 g) and was not correlated with diuretic agent dose (r = 0.06; p = 0.27). Greater sodium excretion was associated with reduced mortality in a univariate model (hazard ratio: 0.80 per doubling of sodium excretion; 95% confidence interval: 0.66 to 0.95; p = 0.01), whereas gross urine output (p = 0.43), net fluid balance (p = 0.87), and weight change (p = 0.11) were not. Sodium excretion of less than the prescribed dietary sodium intake (2 g), even in the setting of a negative net fluid balance, portended a worse prognosis (hazard ratio: 2.02; 95% confidence interval: 1.17 to 3.46; p = 0.01).

CONCLUSIONS

In patients hospitalized with ADHF who were receiving high-dose loop diuretic agents, sodium concentration and excretion were highly variable. Sodium excretion was strongly associated with 6-month mortality, whereas traditional fluid-based metrics were not. Poor sodium excretion, even in the context of fluid loss, portends a worse prognosis.

Effects of empagliflozin on cardiorespiratory fitness and significant interaction of loop diuretics

The effects of empagliflozin on cardiorespiratory fitness in patients with type 2 diabetes mellitus (T2DM) and heart failure with reduced ejection fraction (HFrEF) are unknown. In this pilot study we determined the effects of empagliflozin 10 mg/d for 4 weeks on peak oxygen consumption (VO2 ) in 15 patients with T2DM and HFrEF. As an exploratory analysis, we assessed whether there was an interaction of the effects of empagliflozin on peak VO2 of loop diuretics. Empagliflozin reduced body weight (-1.7 kg; P = .031), but did not change peak VO2 (from 14.5 mL kg-1 min-1 [12.6-17.8] to 15.8 [12.5-17.4] mL kg-1 min-1 ; P = .95). However, patients using loop diuretics (N = 9) demonstrated an improvement, whereas those without loop diuretics (N = 6) experienced a decrease in peak VO2 (+0.9 [0.1-1.4] vs -0.9 [-2.1 to -0.3] mL kg-1 min-1 ; P = .001), and peak VO2 changes correlated with the baseline daily dose of diuretics (R = +0.83; P < .001). Empagliflozin did not improve peak VO2 in patients with T2DM and HFrEF. However, as a result of exploratory analysis, patients concomitantly treated with loop diuretics experienced a significant improvement in peak VO2 .

Vasopressin Receptor Antagonists for the Correction of Hyponatremia in Chronic Heart Failure: An Underutilized Therapeutic Option in Current Clinical Practice?

In the congestive heart failure (CHF) setting, chronic hyponatremia is very common. The present review aims at addressing topics relevant to the pathophysiology of hyponatremia in the course of CHF as well as its optimal treatment, including the main advantages and the limitations resulting from the use of the available dietary and pharmacological measures approved for the treatment of this electrolytic trouble. A narrative review is carried out in order to represent the main modalities of therapy for chronic hyponatremia that frequently complicates CHF. The limits of usual therapies implemented for CHF-related chronic hyponatremia are outlined, while an original analysis of the main advancements achieved with the use of vasopressin receptor antagonists (VRAs) is also executed. The European regulatory restrictions that currently limit the use of VRAs in the management of CHF are substantially caused by financial concerns, i.e., the high costs of VRA therapy. A thoughtful reworking of current restrictions would be warranted in order to enable VRAs to be usefully associated to loop diuretics for decongestive treatment of CHF patients with hyponatremia.

Vasopressin receptor antagonists in patients with chronic heart failure

In this brief review, the pathophysiology of hyponatremia and its clinical significance in the course of chronic heart failure (CHF) are illustrated. Moreover, issues concerning the optimal treatment for hyponatremia during CHF are addressed and discussed. In addition, advantages and limitations resulting from the use of vasopressin receptor antagonists, drugs that have recently emerged as the best available resource against hyponatremia, are highlighted.

Diagnostic value of plasma and urinary 2-hydroxyglutarate to identify patients with isocitrate dehydrogenase-mutated glioma

BACKGROUND

Mutant isocitrate dehydrogenase (IDH) 1/2 enzymes can convert α-ketoglutarate into 2-hydroxyglutarate (2HG). The aim of the present study was to explore whether 2HG in plasma and urine could predict the presence of IDH1/2 mutations in patients with glioma.

MATERIALS AND METHODS

All patients had histological confirmation of glioma and a recent brain magnetic resonance imaging scan showing the neoplastic lesion. Plasma and urine samples were taken from all patients, and the 2HG concentrations were determined using liquid chromatography tandem mass spectrometry.

RESULTS

A total of 84 patients were enrolled: 38 with R132H-IDH1 mutated and 46 with wild type. Among the 38 patients with mutant IDH1, 21 had high-grade glioma and 17 had low-grade glioma. Among the 46 patients with IDH1 wild-type glioma, 35 and 11 had high- and low-grade glioma, respectively. In all patients, we analyzed the mean 2HG concentration in the plasma, urine, and plasma/urine ratio (Ratio_2HG). We found a significant difference in the Ratio_2HG between patients with and without an IDH1 mutation (22.2 ± 8.7 vs. 15.6 ± 6.8; p < .0001). The optimal cutoff value for Ratio_2HG to identify IDH1 mutation was 19 (sensitivity, 63%; specificity, 76%; accuracy, 70%). In the patients with high-grade glioma only, the optimal cutoff value was 20 (sensitivity, 76%; specificity, 89%; accuracy, 84%; positive predictive value, 80%; negative predictive value, 86%). In 7 of 7 patients with high-grade glioma, we found a correlation between the Ratio_2HG value and the response to treatment.

CONCLUSION

Ratio_2HG might be a predictor of the presence of IDH1 mutation. The measurement of 2HG could be useful for disease monitoring and also to assess the treatment effects in these patients.

Intravenous salt supplementation with low-dose furosemide for treatment of acute decompensated heart failure

BACKGROUND

Theoretically, salt supplementation should promote diuresis through increasing the glomerular filtration rate (GFR) during treatment of acute decompensated heart failure (ADHF) even with low-dose furosemide; however, there is little evidence to support this idea.

METHODS AND RESULTS

This was a prospective, randomized, open-label, controlled trial that compared the diuretic effectiveness of salt infusion with that of glucose infusion supplemented with low-dose furosemide in 44 consecutive patients with ADHF. Patients were randomly administered 1.7% hypertonic saline solution supplemented with 40 mg furosemide (salt infusion group) or glucose supplemented with 40 mg furosemide (glucose infusion group). Our major end points were 24-hour urinary volume and GFR. Urinary volume was greater in the salt infusion group than in the glucose infusion group (2,701 ± 920 vs 1,777 ± 797 mL; P < .001). There was no significant difference in the estimated GFR at baseline. Creatinine clearance for 24 h was greater in the salt infusion group than in the glucose infusion group (63.5 ± 52.6 vs 39.0 ± 26.3 mL min(-1) 1.73 m(-2); P = .048).

CONCLUSIONS

Salt supplementation rather than salt restriction evoked favorable diuresis through increasing GFR. The findings support an efficacious novel approach of the treatment of ADHF.