Effect on Survival of Concurrent Hemoconcentration and Increase in Creatinine During Treatment of Acute Decompensated Heart Failure

Identification of three mechanistic pathways for iron-deficient heart failure

Current understanding of iron-deficient heart failure is based on blood tests that are thought to reflect systemic iron stores, but the available evidence suggests greater complexity. The entry and egress of circulating iron is controlled by erythroblasts, which (in severe iron deficiency) will sacrifice erythropoiesis to supply iron to other organs, e.g. the heart. Marked hypoferraemia (typically with anaemia) can drive the depletion of cardiomyocyte iron, impairing contractile performance and explaining why a transferrin saturation < ≈15%-16% predicts the ability of intravenous iron to reduce the risk of major heart failure events in long-term trials (Type 1 iron-deficient heart failure). However, heart failure may be accompanied by intracellular iron depletion within skeletal muscle and cardiomyocytes, which is disproportionate to the findings of systemic iron biomarkers. Inflammation- and deconditioning-mediated skeletal muscle dysfunction-a primary cause of dyspnoea and exercise intolerance in patients with heart failure-is accompanied by intracellular skeletal myocyte iron depletion, which can be exacerbated by even mild hypoferraemia, explaining why symptoms and functional capacity improve following intravenous iron, regardless of baseline haemoglobin or changes in haemoglobin (Type 2 iron-deficient heart failure). Additionally, patients with advanced heart failure show myocardial iron depletion due to both diminished entry into and enhanced egress of iron from the myocardium; the changes in iron proteins in the cardiomyocytes of these patients are opposite to those expected from systemic iron deficiency. Nevertheless, iron supplementation can prevent ventricular remodelling and cardiomyopathy produced by experimental injury in the absence of systemic iron deficiency (Type 3 iron-deficient heart failure). These observations, taken collectively, support the possibility of three different mechanistic pathways for the development of iron-deficient heart failure: one that is driven through systemic iron depletion and impaired erythropoiesis and two that are characterized by disproportionate depletion of intracellular iron in skeletal and cardiac muscle. These mechanisms are not mutually exclusive, and all pathways may be operative at the same time or may occur sequentially in the same patients.

Long-term outcomes of acute kidney injury in acute decompensated heart failure: identifying true cardiorenal syndrome and unveiling prognostic significance

BACKGROUND

Cardiorenal syndrome (CRS) type 1 defined as acute kidney injury (AKI) in acute decompensated heart failure (ADHF), is complicated due to diverse definitions. Recently, a more precise CRS type 1 definition was proposed, mandating concurrent AKI and signs of unimproved heart failure (HF). Our study explores the incidence, predictors, and long-term outcomes of AKI in ADHF under this new definition.

METHODS

A prospective observation study of ADHF patients categorized into the CRS type 1, pseudo-CRS, and non-AKI groups, followed for 12 months. CRS type 1 involved AKI with clinical congestion, while pseudo-CRS included AKI with clinical decongestion (clinical congestion score <2). The primary outcome was a 1-year composite of mortality or HF rehospitalization.

RESULTS

Among 250 consecutive ADHF patients, 46.0% developed CRS type 1; chronic kidney disease (CKD) and blood urea nitrogen were significant risk factors (odds ratios, 1.37; p = 0.002 and OR, 1.05; p < 0.001, respectively). The CRS type 1 group exhibited shorter times to AKI development and peak serum creatinine than the pseudo-CRS group (1 day vs. 4 days and 2 days vs. 4 days, respectively). At 12 months, composite outcomes of mortality or HF rehospitalization and CKD progression were significantly higher in the CRS type 1 group than in the pseudo-CRS and non-AKI groups (63.5% vs. 31.7% vs. 36.1%, p < 0.001; 28.1% vs. 16.2% vs. 11.4%, p = 0.024, respectively).

CONCLUSION

Distinguishing between CRS type 1 and pseudo-CRS is vital, highlighting significant disparities in short-term and longterm outcomes. Notably, pseudo-CRS exhibits comparable long-term cardiovascular and renal outcomes to those without AKI.

Impact of mitral regurgitation in patients with acute heart failure: insights from the RELAX-AHF-2 trial

AIMS

The impact of mitral regurgitation (MR) in patients hospitalized for acute heart failure (AHF) is not well established. We assessed the role of MR in patients enrolled in the Relaxin in Acute Heart Failure 2 (RELAX-AHF-2) trial.

METHODS AND RESULTS

Patients enrolled in RELAX-AHF-2 with available data regarding MR status were included in this analysis. Baseline characteristics, in-hospital data, and clinical outcomes through 180-day follow-up were evaluated. The impact of moderate/severe MR was assessed. Among 6420 AHF patients with known MR status, 1810 patients (28.2%) had moderate/severe MR. Compared to patients with no/mild MR, those with moderate/severe MR were more likely to have history of heart failure (HF), prior HF hospitalization, more comorbidities, symptoms/signs of HF, lower left ventricular ejection fraction and higher N-terminal pro-B-type natriuretic peptide levels. Moderate/severe MR was associated with longer length of hospital stay, higher rates of residual dyspnoea, increased jugular venous pressure through the index hospitalization and a higher unadjusted risk of the composite of cardiovascular (CV) death or rehospitalization for HF/renal failure (RF) through 180 days (crude hazard ratio [HR] 1.15, 95% confidence interval [CI] 1.03-1.27, p = 0.01). The association between moderate/severe MR and poorer outcomes was not maintained in a multivariable model including several covariates of interest (adjusted HR 1.03, 95% CI 0.91-1.17, p = 0.65). Similar findings were observed for HF/RF rehospitalization alone.

CONCLUSIONS

In patients with AHF, moderate/severe MR was associated with a worse clinical profile but did not have an independent prognostic impact on clinical outcomes.

Relationship between BUN/Cr and Prognosis of HF Across the Full Spectrum of Ejection Fraction

BACKGROUND

In patients with heart failure (HF), due to the relative deficiency of blood volume, neurohormone system activation leads to renal vasoconstriction, which affects the content of blood urea nitrogen (BUN) and creatinine (Cr) in the body, while BUN and Cr are easily affected by other factors. Therefore, BUN/Cr can be used as another marker for the prognosis of HF.

OBJECTIVE

Explore the prognosis of adverse outcome of HF in the high BUN/Cr group compared with the low BUN/Cr group across the full spectrum of ejection fraction.

METHODS

From 2014 to 2016, symptomatic hospitalized HF patients were recruited and followed up to observe adverse cardiovascular outcomes. Logistic analysis and COX analysis were performed to determine significance. p-values <0.05 were considered statistically significant.

RESULTS

In the univariate logistic regression analysis, the high BUN/Cr group had a higher risk of adverse outcome in heart failure with reduced ejection fraction (HFrEF) and heart failure with preserved ejection fraction (HFpEF). Multivariate logistic regression analysis showed that the risk of cardiac death in the HFrEF group was higher than that in the low BUN/Cr group, while the risk of all-cause death was significant only in 3 months (p<0.05) (Central Illustration). The risk of all-cause death in the high BUN/Cr in the HFpEF group was significantly higher than that in the low BUN/Cr group at two years.

CONCLUSION

The high BUN/Cr group is related to the risk of poor prognosis of HFpEF, and is not lower than the predictive value of left ventricular ejection fraction (LVEF).

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.

Rates of Reversal of Volume Overload in Hospitalized Acute Heart Failure: Association With Long-term Kidney Function

RATIONALE & OBJECTIVE

Achievement of decongestion in acute heart failure (AHF) is associated with improved survival and cardiovascular outcomes but can be associated with acute declines in estimated glomerular filtration rate (eGFR). We examined whether the rate of in-hospital decongestion is associated with longer term kidney function decline.

STUDY DESIGN

Post hoc analysis of trial data.

SETTINGS & PARTICIPANTS

Patients with ≥2 measures of kidney function (n = 3,500) from the Efficacy of Vasopressin Antagonism in Heart Failure Outcome Study With Tolvaptan (EVEREST) trial.

EXPOSURE

In-hospital rate of change in assessments of volume overload, including B-type natriuretic peptide (BNP), N-terminal pro-B-type natriuretic peptide (NT-proBNP), and clinical congestion score (0-12); and rate of change in hemoconcentration including measures of hematocrit, albumin, and total protein.

OUTCOME

Incident chronic kidney disease GFR category 4 or worse (chronic kidney disease [CKD] categories G4-G5; defined by a new eGFR of <30 mL/min/1.73 m²) and eGFR decline of >40%.

ANALYTICAL APPROACH

Multivariable cause-specific hazards models.

RESULTS

Over median 10-month follow-up period, faster decreases in volume overload and more rapid increases in hemoconcentration were associated with a decreased risk of incident CKD G4-G5 and eGFR decline of >40%. In adjusted analyses, for every 6% faster decline in BNP per week, there was a 32% lower risk of both incident CKD G4-G5 (HR, 0.68 [95% CI, 0.58-0.79]) and eGFR decline of >40% (HR, 0.68 [95% CI, 0.57-0.80]). For every 1% faster increase per week in absolute hematocrit, there was a lower risk for both incident CKD G4-G5 (HR, 0.73 [95% CI, 0.64-0.84]) and eGFR decline of >40% (HR, 0.82 [95% CI, 0.71-0.95]), with results consistent for other biomarkers.

LIMITATIONS

Possibility of residual confounding.

CONCLUSIONS

These results provide reassurance that more rapid decongestion in patients with AHF does not increase the risk of adverse kidney outcomes in patients with heart failure.

Inferior Vena Cava Diameter Measurement Provides Distinct and Complimentary Information to Right Atrial Pressure in Acute Decompensated Heart Failure

BACKGROUND

Inferior vena cava (IVC) measurements only correlate modestly with right atrial pressure (RAP). Part of this inaccuracy is due to the high compliance of the venous system where a large change in blood volume may result in only a small change in pressure. As such, the information provided by the IVC may be different rather than redundant.

METHODS AND RESULTS

We analyzed patients in the ESCAPE trial who had both pulmonary artery catheter and IVC measurements at baseline (n =108). There was only a modest correlation between baseline RAP and IVC diameter (r =0.41, p<0.001). Hemoconcentration, defined as an increase in hemoglobin from admission to discharge, was correlated with decrease in IVC diameter (r =0.35, p =0.02), but not with a decrease in RAP (r =0.01, p =0.95). When patients had both IVC and RAP measurements below the median, survival was superior to those who had only one below the median, and both above the median fared the worst (p=0.002).

CONCLUSION

IVC and RAP have limited correlation with one another, and changes in intravascular volume appear to correlate better with IVC diameter rather than RAP. Furthermore, there is complimentary information provided by pressure and volume assessments in ADHF.

The Effect in Renal Function and Vascular Decongestion in Type 1 Cardiorenal Syndrome Treated with Two Strategies of Diuretics, a Pilot Randomized Trial

Aim

The main treatment strategy in type 1 cardiorenal syndrome (CRS1) is vascular decongestion. It is probable that sequential blockage of the renal tubule with combined diuretics (CD) will obtain similar benefits compared with stepped-dose furosemide (SF).

Methods

In a pilot double-blind randomized controlled trial of CRS1 patients were allocated in a 1:1 fashion to SF or CD. The SF group received a continuous infusion of furosemide 100 mg during the first day, with daily incremental doses to 200 mg, 300 mg and 400 mg. The CD group received a combination of diuretics, including 4 consecutive days of oral chlorthalidone 50 mg, spironolactone 50 mg and infusion of furosemide 100 mg. The objectives were to assess renal function recovery and variables associated with vascular decongestion.

Results

From July 2017 to February 2020, 80 patients were randomized, 40 to the SF and 40 to the CD group. Groups were similar at baseline and had several very high-risk features. Their mean age was 59 ± 14.5 years, there were 37 men (46.2%). The primary endpoint occurred in 20% of the SF group and 15.2% of the DC group (p = 0.49). All secondary and exploratory endpoints were similar between groups. Adverse events occurred frequently (85%) with no differences between groups (p = 0.53).

Conclusion

In patients with CRS1 and a high risk of resistance to diuretics, the use of CD compared to SF offers the same results in renal recovery, diuresis, vascular decongestion and adverse events, and it can be considered an alternative treatment. ClinicalTrials.gov with number NCT04393493 on 19/05/2020 retrospectively registered.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-021-02637-y.

Tricuspid regurgitation pressure gradient identifies prognostically relevant worsening renal function in acute heart failure

AIMS

Not all worsening renal function (WRF) during heart failure treatment is associated with a poor prognosis. However, a metric capable providing a prognosis of relevant WRF has not been developed. Our aim was to evaluate if a change in tricuspid regurgitation pressure gradient (TRPG) could discriminate prognostically relevant and not relevant WRF in patients with acute heart failure (AHF).

METHODS AND RESULTS

We examined 809 consecutive hospitalized patients with heart failure (78 ± 12 years, 54% male). WRF was defined as an increase in creatinine >0.3 mg and ≥25% from admission to discharge. TRPG was measured at admission and before discharge using echocardiography. The primary outcome was all-cause death within 1-year after discharge. Patients were classified as follows for analysis: no WRF and no TRPG increase (n = 523); no WRF and TRPG increase (no WRF with iTRPG, n = 170); WRF and no TRPG increase (WRF without iTRPG, n = 90); and WRF and TRPG increase (WRF with iTRPG, n = 26). A change in TRPG weakly but significantly correlated to a change in haemoglobin and haematocrit, a percent decrease in brain natriuretic peptide, and body weight reduction during the index period of hospitalization. All-cause mortality within 1 year was higher in patients with WRF and iTRPG, compared to the other three groups (P = 0.026). On Cox regression analysis, only WRF with iTRPG was associated with higher mortality (hazard ratio 4.24, P = 0.001), even after adjustment for other confounders.

CONCLUSION

An increase in TRPG may provide a marker to identify prognostically relevant WRF in patients with AHF.

Serum creatinine and cystatin C-based estimates of glomerular filtration rate are misleading in acute heart failure

AIMS

We aimed to test whether the endogenous filtration markers serum creatinine or cystatin C and equation-based estimates of glomerular filtration rate (GFR) based on these markers appropriately reflect changes of measured GFR in patients with acute heart failure.

METHODS

In this prospective cohort study of 50 hospitalized acute heart failure patients undergoing decongestive therapy, we applied an intravenous visible fluorescent injectate (VFI), consisting of a low molecular weight component to measure GFR and a high molecular weight component to correct for measured plasma volume. Thirty-eight patients had two sequential GFR measurements 48 h apart. The co-primary endpoints of the study were safety of VFI and plasma stability of the high molecular weight component. A key secondary endpoint was to compare changes in measured GFR (mGFR) to changes of serum creatinine, cystatin C and estimated GFR.

RESULTS

VFI-based GFR measurements were safe and consistent with plasma stability of the high molecular weight component and glomerular filtration of the low molecular weight component. Filtration marker-based point estimates of GFR, when compared with mGFR, provided only moderate correlation (Pearson's r, range 0.80-0.88, depending on equation used), precision (r2 , range 0.65-0.78) and accuracy (56%-74% of estimates scored within 30% of mGFR). Correlations of 48-h changes GFR estimates and changes of mGFR were significant (P < 0.05) but weak (Pearson's r, range 0.35-0.39). Observed decreases of eGFR by more than 15% had a low sensitivity (range 38%-46%, depending on equation used) in detecting true worsening mGFR, defined by a >15% decrease in mGFR.

CONCLUSIONS

In patients hospitalized for acute heart failure, serum creatinine- and cystatin C-based predictions performed poorly in detecting actual changes of GFR. These data challenge current clinical strategies to evaluate dynamics of kidney function in acute heart failure.

Empagliflozin in Heart Failure: Diuretic and Cardiorenal Effects

BACKGROUND

Sodium-glucose cotransporter-2 inhibitors improve heart failure-related outcomes. The mechanisms underlying these benefits are not well understood, but diuretic properties may contribute. Traditional diuretics such as furosemide induce substantial neurohormonal activation, contributing to the limited improvement in intravascular volume often seen with these agents. However, the proximal tubular site of action of the sodium-glucose cotransporter-2 inhibitors may help circumvent these limitations.

METHODS

Twenty patients with type 2 diabetes mellitus and chronic, stable heart failure completed a randomized, placebo-controlled crossover study of empagliflozin 10 mg daily versus placebo. Patients underwent an intensive 6-hour biospecimen collection and cardiorenal phenotyping at baseline and again after 14 days of study drug. After a 2-week washout, patients crossed over to the alternate therapy with the above protocol repeated.

RESULTS

Oral empagliflozin was rapidly absorbed as evidenced by a 27-fold increase in urinary glucose excretion by 3 hours (P<0.0001). Fractional excretion of sodium increased significantly with empagliflozin monotherapy versus placebo (fractional excretion of sodium, 1.2±0.7% versus 0.7±0.4%; P=0.001), and there was a synergistic effect in combination with bumetanide (fractional excretion of sodium, 5.8±2.5% versus 3.9±1.9%; P=0.001). At 14 days, the natriuretic effect of empagliflozin persisted, resulting in a reduction in blood volume (-208 mL [interquartile range, -536 to 153 mL] versus -14 mL [interquartile range, -282 to 335 mL]; P=0.035) and plasma volume (-138 mL, interquartile range, -379 to 154±453 mL; P=0.04). This natriuresis was not, however, associated with evidence of neurohormonal activation because the change in norepinephrine was superior (P=0.02) and all other neurohormones were similar (P<0.34) during the empagliflozin versus placebo period. Furthermore, there was no evidence of potassium wasting (P=0.20) or renal dysfunction (P>0.11 for all biomarkers), whereas both serum magnesium (P<0.001) and uric acid levels (P=0.008) improved.

CONCLUSIONS

Empagliflozin causes significant natriuresis, particularly when combined with loop diuretics, resulting in an improvement in blood volume. However, off-target electrolyte wasting, renal dysfunction, and neurohormonal activation were not observed. This favorable diuretic profile may offer significant advantage in the management of volume status in patients with heart failure and may represent a mechanism contributing to the superior long-term heart failure outcomes observed with these agents. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03027960.