Fluid loss, venous congestion, and worsening renal function in acute decompensated heart failure

Congestion/decongestion in heart failure: what does it mean, how do we assess it, and what are we missing?-is there utility in measuring volume?

Clinical congestion remains a major cause of hospitalization and re-hospitalizations in patients with chronic heart failure (HF). Despite the high prevalence of this issue and clinical concern in HF practice, there is limited understanding of the complex pathophysiology relating to the "congestion" of congestive HF. There is no unifying definition or clear consensus on what is meant or implied by the term "congestion." Further, the discordance in study findings relating congestion to physical signs and symptoms of HF, cardiac hemodynamics, or metrics of weight change or fluid loss with diuretic therapy has not added clarity. In this review, these factors will be discussed to add perspective to this issue and consider the factors driving "congestion." There remains a need to better understand the roles of fluid retention promoting intravascular and interstitial compartment expansions, blood volume redistribution from venous reservoirs, altered venous structure and capacity, elevated cardiac filling pressure hemodynamics, and heterogeneous intravascular volume profiles (plasma volume and red blood cell mass) with a goal to help demystify "congestion" in HF. Further, this includes highlighting the importance of recognizing that congestion is not the result of a single pathway but a complex of responses some of which produce symptoms while others do not; yet, we confine these varied responses to the single and somewhat vague term "congestion."

Acute Kidney Injury in Patients Undergoing Both Right and Left Heart Catheterization with Coronary Angiography Vs Right Heart Catheterization Only

BACKGROUND

Recent studies have challenged the reported causal association between acute kidney injury and iodinated contrast administration, ascribing some cases to changes in renal function that are independent of contrast administration.

METHODS

We studied 1779 consecutive patients undergoing right heart catheterization (RHC) at a Veterans Administration Medical Center. We compared the incidence of acute kidney injury and of nephropathy at 3 months in veterans undergoing right and left heart catheterization and coronary angiography (R&LHC) to the incidence of acute kidney injury and of nephropathy at 3 months in patients undergoing RHC only.

RESULTS

The incidence of acute kidney injury at 3 days was 47 (9.7%) in the R&LHC group and 58 (9.6%) in the RHC group (P = .99). The incidence of nephropathy at 3 months was 115 (17%) in the L&RHC group and 141 (19.2%) in the RHC group (P = 0.31). In a propensity score-paired analysis of 782 patients and after adjustment for baseline characteristics, the odds ratio for acute kidney injury at 3 days among patients undergoing R&LHC was 1.25 (95% confidence interval, 0.65-2.42; P = .50), and the odds ratio for nephropathy at 3 months was 0.69 (95% confidence interval, 0.46-1.04; P = .08).

CONCLUSION

The incidence of changes in creatinine consistent with acute kidney injury at 3 days and of nephropathy at 3 months was not significantly different in patients undergoing R&LHC compared with patients undergoing RHC only. This supports the thesis that not all changes in creatinine after procedures involving administration of contrast are caused by the contrast.

The Association Between Intra-abdominal Pressure and Diuretic Response in Heart Failure

PURPOSE OF THE REVIEW

An efficient diuretic response is vital during cardiac decompensation in heart failure (HF) patients. The increase in intra-abdominal pressure (IAP) could be one of the keys for understanding cardiorenal syndrome and guiding diuretic treatment during hospitalization. In this review, we analyze the relationship between IAP and diuretic response in HF patients.

RECENT FINDINGS

Increased IAP is associated with worsening renal function (WRF) in patients with advanced HF. Furthermore, the persistence of a rise in IAP after the first 72 h of intravenous diuretic treatment has been correlated with a worse diuretic response, a higher degree of congestion, and an impaired prognosis. The rise in IAP in HF patients has been associated with impaired renal function and a lower diuretic response. Nonetheless, more studies are needed to elucidate the actual role of IAP in congestive nephropathy and whether it may help guide diuretic therapy during acute decompensations.

An Individual Patient-Level Meta-Analysis of Ischemic Versus Nonischemic Cardiomyopathy and Trajectory of Decongestion in Patients With Acute Decompensated Heart Failure

Data are limited regarding the impact of ischemic cardiomyopathy (ICM) or non-ICM (NICM) on the trajectory of in-hospital decongestion among patients with acute decompensated heart failure (ADHF). Therefore, we aimed to assess the course of decongestion among patients admitted for ADHF by history of ICM and NICM. Patients included in the DOSE (Diuretic strategies in patients with acute decompensated heart failure), ROSE (ROSE acute heart failure randomized trial), and Ultrafiltration in decompensated heart failure with cardiorenal syndrome (CARRESS-HF) trials of patients with ADHF were categorized into ICM and NICM based on history. Among 762 patients included in our meta-analysis, 433 (56.8%) had a history of ICM. Patients with ICM were older (70.8 vs 63.9 years; p ≤0.001) and had higher rates of co-morbidities. After covariate adjustment, there was no significant differences between NICM and ICM regarding net fluid loss (4,952 vs 4,384 ml, p = 0.81) or mean change in serum N-terminal pro-brain natriuretic peptide (-2,162 vs -1,809 pg/ml, p = 0.092). Mean change in weight showed modest improvement in favor of patients with NICM, but this did not meet statistical significance (-8.24 vs -7.70 pounds, p = 0.068). After adjustment, there was no significant difference in the risk of 60-day composite all-cause mortality or hospitalization for HF among those with ICM versus NICM. Among patients with left ventricular ejection fraction <40%, NICM was associated with higher scoring on global sense of well-being (global visual analog scale; +25.5 vs +19.1, p = 0.023) and improvement in serum creatinine (-0.031 mg/100 ml vs +0.042 mg/100 ml, p = 0.009) at 72 hours. Among patients with left ventricular ejection fraction >40%, NICM was associated with decreased scoring on global visual analog scale at 72 hours (+15.7 vs +21.2, p = 0.049). In conclusion, more than half of the patients admitted for ADHF had ICM. History of ICM was not independently associated with a difference in course of decongestion, self-assessment of well-being and dyspnea, or short-term clinical outcomes.

Cardiorenal Syndrome in the Hospital

The cardiorenal syndrome refers to a group of complex, bidirectional pathophysiological pathways involving dysfunction in both the heart and kidney. Upward of 60% of patients admitted for acute decompensated heart failure have CKD, as defined by an eGFR of <60 ml/min per 1.73 m 2 . CKD, in turn, is one of the strongest risk factors for mortality and cardiovascular events in acute decompensated heart failure. Although not well understood, the mechanisms in the cardiorenal syndrome include venous congestion, arterial underfilling, neurohormonal activation, inflammation, and endothelial dysfunction. Arterial underfilling may lead to activation of the renin-angiotensin-aldosterone system and sympathetic nervous system, leading to sodium reabsorption and vasoconstriction. Venous congestion likely also mediates and perpetuates these maladaptive pathways. To rule out intrinsic kidney disease that is distinct from the cardiorenal syndrome, one should obtain a careful history, review longitudinal eGFR trends, assess albuminuria and proteinuria, and review the urine sediment and kidney imaging. The hallmark of the cardiorenal syndrome is intense sodium avidity and diuretic resistance, often requiring a combination of diuretics with varying pharmacological targets, and monitoring of urinary response to guide escalations in therapy. Invasive means of decongestion may be required including ultrafiltration or KRT such as peritoneal dialysis, which is often better tolerated from a hemodynamic perspective than intermittent hemodialysis. Strategies for increasing forward perfusion in states of low cardiac output and cardiogenic shock may include afterload reduction and inotropes and, in the most severe cases, mechanical circulatory support devices, many of which have kidney-specific considerations.

Measurement of Blood Volume in Patients with Heart Failure: Clinical Relevance, Surrogates, Historical Background and Contemporary Methodology

The development of clinical congestion resulting from volume overload, either by renal fluid retention or redistribution of blood volume from venous reservoirs, is a recurrent scenario in patients with chronic heart failure (HF). As a result, the treatment of congestion, most commonly by initiating aggressive diuretic therapy, is a front-line issue in the management of patients with HF. However, the association of clinical congestion and volume overload with physical signs and symptoms, as well as other surrogates of volume assessment, has limitations in accuracy and, therefore, reliability to direct appropriate interventions. The ability to quantitate intravascular volume and identify the variability in volume profiles among patients with HF can uniquely inform individualized volume management and aid in risk stratification. This tool is provided by contemporary nuclear medicine-based BVA-100 methodology, which uses the well-established indicator-dilution principle and is a requested topic for discussion in this review.

Association of serum N-terminal pro-brain natriuretic peptide levels with survival and renal outcomes among elderly patients with acute kidney injury in chronic heart failure

Background

Elderly patients exhibit a higher incidence of chronic heart failure (CHF). Patients with CHF can develop acute kidney injury (AKI) during follow-up, which can result in poor prognosis. This relationship between kidney dysfunction and levels of N-terminal pro-brain natriuretic peptides (NT-proBNP), with regard to prognosis, is complicated and has rarely been analyzed in elderly patients with CHF.

Method

We conducted a retrospective cohort study involving patients with a CHF history aged ≥ 65 years, who experienced an episode of AKI. Kaplan-Meier curves and Cox or logistic proportional hazards regression models were used to evaluate the association between serum NT-proBNP concentrations and mortality or renal recovery by day 90.

Results

A total of 1,160 eligible patients with AKI were available for the study. Of this sample, 41.5% of patients died within 90 days of the onset of AKI. Patients with a decreased change in NT-proBNP accompanying the episode of AKI had a lower risk (adjusted OR = 0.56, 95% CI = 0.34-0.91) of more severe AKI (stage 2 and 3 vs. stage 1). The more severe AKI were associated with higher mortality and non-recovery of renal function in elderly patients with CHF, independent of NT-proBNP levels. Elevated levels of baseline lnNT-proBNP (adjusted HR = 1.27, 95% CI = 1.17-1.38) predicted mortality in elderly patients with CHF within 90 days of AKI onset. Patients with a decrease in NT-proBNP accompanying AKI had a lower risk of mortality (adjusted HR = 0.62, 95% CI = 0.48-0.79). However, a decrease in NT-proBNP is a risk factor (adjusted OR = 1.59, 95% CI = 1.02-2.48) for the non-recovery of renal function following AKI-especially in elderly survivors with low baseline NT-proBNP levels.

Conclusion

A decreased change in NT-proBNP maybe protective for elderly patients with CHF by improving survival outcomes and preventing severe AKI. However, an excessive decrease in NT-proBNP is a risk factor for the non-recovery of renal function following AKI. Avoiding excessive changes in NT-proBNP may be protective for survival and renal injury prognosis.

Body fluid regulation via chronic inhibition of sodium-glucose cotransporter-2 in patients with heart failure: a post hoc analysis of the CANDLE trial

BACKGROUND

In patients with chronic heart failure (CHF) and type 2 diabetes (T2D), sodium-glucose cotransporter-2 (SGLT2) inhibition improves cardiorenal outcomes, but details of the effects on distinct subsets of body fluid volume remain incomplete.

METHODS

This was a post hoc analysis of patients with CHF and T2D in the CANDLE trial (UMIN000017669), an investigator-initiated, multi-center, randomized open-label trial that compared the effect of canagliflozin (100 mg, n = 113) with glimepiride (starting dose: 0.5 mg, n = 120) on changes in N-terminal pro-brain natriuretic peptide. The estimated plasma volume (ePV, calculated with the Straus formula) and estimated extracellular volume (eEV, determined by the body surface area) were compared between treatment groups at weeks 4, 12, and 24.

RESULTS

Among 233 patients analyzed, 166 (71.2%) had an ejection fraction (EF) > 50%. Reductions in ePV and eEV were observed only in the canagliflozin group until week 12 (change from baseline at week 12, ePV; - 7.63%; 95% confidence interval [CI], - 10.71 to - 4.55%, p < 0.001, eEV; - 123.15 mL; 95% CI, - 190.38 to - 55.92 mL, p < 0.001). While ePV stopped falling after week 12, eEV continued to fall until week 24 ([change from baseline at week 24] - [change from baseline at week 12], ePV; 1.01%; 95%CI, - 2.30-4.32%, p = 0.549, eEV; - 125.15 mL; 95% CI, - 184.35 to - 65.95 mL, p < 0.001).

CONCLUSIONS

Maintenance of a modest reduction in ePV and continuous removal of eEV via chronic SGLT2 inhibition suggests that favorable body fluid regulation contributes to the cardiorenal benefits of SGLT2 inhibitors in patients with CHF, irrespective of EF.

TRIAL REGISTRATION

UMIN000017669.

Doppler study of portal vein and renal venous velocity predict the appropriate fluid response to diuretic in ICU: a prospective observational echocardiographic evaluation

BACKGROUND

Fluid overload and venous congestion are associated with morbi-mortality in the ICU (intensive care unit). Administration of diuretics to correct the fluid balance is common, although there is no strong relationship between the consequent fluid loss and clinical improvement. The aim of the study was to evaluate the ability of the portal pulsatility index, the renal venous impedance index, and the VEXUS score (venous ultrasound congestion score) to predict appropriate diuretic-induced fluid depletion.

METHODS

The study had a prospective, observational, single-center observational design and was conducted in a university-affiliated medico-surgical ICU. Adult patients for whom the clinician decided to introduce loop diuretic treatment were included. Hemodynamic and ultrasound measurements (including the portal pulsatility index, renal venous impedance index and VEXUS score) were performed at inclusion and 2 hours after the initiation of the diuretics. The patients' characteristics were noted at inclusion, 24 h later, and at ICU discharge. The appropriate diuretic-induced fluid depletion was defined by a congestive score lower than 3 after diuretic fluid depletion. The congestive score included clinical and biological parameters of congestion.

RESULTS

Eighty-one patients were included, and 43 (53%) patients presented with clinically significant congestion score at inclusion. Thirty-four patients (42%) had an appropriate response to diuretic-induced fluid depletion. None of the left- and right-sided echocardiographic parameters differed between the two groups. The baseline portal pulsatility index was the best predictor of appropriate response to diuretic-induced fluid depletion (AUC = 0.80, CI_95%:0.70-0.92, p = 0.001), followed by the renal venous impedance index (AUC = 0.72, CI_95% 0.61-0.84, p = 0.001). The baseline VEXUS score (AUC of 0.66 CI_95% 0.53-0.79, p = 0.012) was poorly predictive of appropriate response to diuretic-induced fluid depletion.

CONCLUSION

The portal pulsatility index and the renal venous impedance index were predictive of the appropriate response to diuretic-induced fluid depletion in ICU patients. The portal pulsatility index should be evaluated in future randomized studies.

Edema formation in congestive heart failure and the underlying mechanisms

Congestive heart failure (HF) is a complex disease state characterized by impaired ventricular function and insufficient peripheral blood supply. The resultant reduced blood flow characterizing HF promotes activation of neurohormonal systems which leads to fluid retention, often exhibited as pulmonary congestion, peripheral edema, dyspnea, and fatigue. Despite intensive research, the exact mechanisms underlying edema formation in HF are poorly characterized. However, the unique relationship between the heart and the kidneys plays a central role in this phenomenon. Specifically, the interplay between the heart and the kidneys in HF involves multiple interdependent mechanisms, including hemodynamic alterations resulting in insufficient peripheral and renal perfusion which can lead to renal tubule hypoxia. Furthermore, HF is characterized by activation of neurohormonal factors including renin-angiotensin-aldosterone system (RAAS), sympathetic nervous system (SNS), endothelin-1 (ET-1), and anti-diuretic hormone (ADH) due to reduced cardiac output (CO) and renal perfusion. Persistent activation of these systems results in deleterious effects on both the kidneys and the heart, including sodium and water retention, vasoconstriction, increased central venous pressure (CVP), which is associated with renal venous hypertension/congestion along with increased intra-abdominal pressure (IAP). The latter was shown to reduce renal blood flow (RBF), leading to a decline in the glomerular filtration rate (GFR). Besides the activation of the above-mentioned vasoconstrictor/anti-natriuretic neurohormonal systems, HF is associated with exceptionally elevated levels of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP). However, the supremacy of the deleterious neurohormonal systems over the beneficial natriuretic peptides (NP) in HF is evident by persistent sodium and water retention and cardiac remodeling. Many mechanisms have been suggested to explain this phenomenon which seems to be multifactorial and play a major role in the development of renal hyporesponsiveness to NPs and cardiac remodeling. This review focuses on the mechanisms underlying the development of edema in HF with reduced ejection fraction and refers to the therapeutic maneuvers applied today to overcome abnormal salt/water balance characterizing HF.

Fluid Volume Homeostasis in Heart Failure: A Tale of 2 Circulations

Fluid volume homeostasis in health and heart failure (HF) requires a complex interaction of 2 systems, the intravascular and interstitial-lymphatic circulations. With the development of HF both the intravascular and interstitial compartments undergo variable degrees of volume remodeling which can include significant expansion. This reflects the impact of multiple pathophysiologic mechanisms on both fluid compartments which initially play a compensatory role to stabilize intravascular circulatory integrity but with progression in HF can evolve to produce the various manifestations of volume overload and clinical HF congestion. The intent of this review is to help enhance recognition of the pathophysiologic and clinical importance of the interlinked roles of these 2 circulatory systems in volume regulation and chronic HF. It would also be hoped that a better understanding of the interacting functions of the intravascular and interstitial-lymphatic fluid compartments can potentially aid development of novel management strategies particularly addressing the generally undertargeted interstitial-lymphatic system and help bring such approaches forward through a more integrated view of these 2 circulatory systems.

Predictors of Exercise Capacity in Dilated Cardiomyopathy with Focus on Pulmonary Venous Flow Recorded with Transesophageal Eco-Doppler

The aim of this study was to clarify the relative contribution of elevated left ventricle (LV) filling pressure (FP) estimated by pulmonary venous (PV) and mitral flow, transesophageal Doppler recording (TEE), and other extracardiac factors like obesity and renal insufficiency (KI) to exercise capacity (ExC) evaluated by cardiopulmonary exercise testing (CPX) in patients with dilated cardiomyopathy (DCM). During the CPX test, 119 patients (pts) with DCM underwent both peak VO₂ consumption and then TEE with color-guided pulsed-wave Doppler recording of PVF and transmitral flow. In 78 patients (65%), peak VO₂ was normal or mildly reduced (>14 mL/kg/min) (group 1) while it was markedly reduced (≤14 mL/kg/min) in 41 (group 2). In univariate analysis, systolic fraction (S Fract), a predictor of elevated pre-a LV diastolic FP, appeared to be the best diastolic parameter predicting a significantly reduced peak VO₂. Logistic regression analysis identified five parameters yielding a unique, statistically significant contribution in predicting reduced ExC: creatinine clearance < 52 mL/min (odds ratio (OR) = 7.4, p = 0.007); female gender (OR = 7.1, p = 0.004); BMI > 28 (OR = 5.8, p = 0.029), age > 62 years (OR = 5.5, p = 0.03), S Fract < 59% (OR = 4.9, p = 0.02). Conclusion: KI was the strongest predictor of reduced ExC. The other modifiable factors were obesity and severe LV diastolic dysfunction expressed by blunted systolic venous flow. Contrarily, LV ejection fraction was not predictive, confirming other previous studies. This has important clinical implications.

Variability in estimated glomerular filtration rate and patients' outcomes in a real-world heart failure population

Aims

The prognostic significance of renal function variability has not been fully elucidated in heart failure (HF). This multicentre, prospective cohort study aimed to evaluate the usefulness of visit‐to‐visit variability in estimated glomerular filtration rate (eGFR) for predicting patients' outcomes in a real‐world HF population.

Methods

A total of 564 patients who had survived HF hospitalization were randomly assigned with a 2:1 ratio to derivation and validation cohorts, and they were then followed after discharge. Using the data for 6 months after discharge, each patient's visit‐to‐visit eGFR variability (EGV) was estimated. In the derivation cohort, Cox regression analyses were performed to assess the association of EGV with a subsequent composite event (death and HF hospitalization). In the validation cohort, the predictive performance was compared among Cox regression models with EGV, those with B‐type natriuretic peptide (BNP) and those with eGFR.

Results

In the derivation cohort (376 patients), median age, left ventricular ejection fraction (LVEF), BNP and eGFR at discharge were 72 years, 53.3%, 134.8 pg/mL and 58.7 mL/min/1.73 m², respectively. During a median follow‐up of 2.2 years, higher EGV was associated with an increased risk of the composite event (adjusted hazard ratio [per standard deviation increase in log‐transformed EGV], 1.5; 95% confidence interval, 1.1–2.0). A similar finding was observed in a stratified analysis by LVEF. In the validation cohort (188 patients), better model fit, discrimination, reclassification and calibration were observed for EGV than for 6‐month averaged BNP or eGFR for predicting the composite event when added to HF risk prediction models. Adding EGV to models with BNP or eGFR improved model discrimination and reclassification.

Conclusions

EGV predicts HF outcomes regardless of LVEF. Risk prediction models with EGV have good performance in real‐world HF patients. The study findings highlight the clinical importance of observing visit‐to‐visit fluctuations in renal function in this population.

Arginine Vasopressin as an Important Mediator of Fluctuations in the Serum Creatinine Concentration Under Decongestion Treatment in Heart Failure Patients

Background: The mechanism underlying serum creatinine (SCr) fluctuations in heart failure (HF) patients remains unclear. This study examined mediators of SCr fluctuations under diuretic treatment in HF patients.

Methods and Results: Data from 26 HF patients were analyzed. Clinical tests included measurement of peripheral blood, blood urea nitrogen, SCr, serum and urinary electrolytes, B-type natriuretic peptide (BNP), and plasma neurohormones. Among the 26 patients recovering from worsening HF, changes in SCr were negatively correlated with changes in serum Cl, and positively correlated with changes in plasma arginine vasopressin (AVP). According to the median change in SCr, patients were divided into high (range 0.16–0.79 mg/dL; n=13) and low (range −0.35 to 0.14 mg/dL; n=13) change groups. Plasma AVP concentrations after treatment decreased in the low SCr change group and increased in the high SCr change group (−1.28±2.8 vs. 2.14±4.4 pg/mL, respectively; P=0.027). In both groups, there was no change in plasma volume, plasma BNP and norepinephrine concentrations decreased, and plasma renin activity increased after treatment. Multivariate logistic regression analysis showed a tendency towards an independent association between an increase in SCr and an increase or no change in the plasma AVP after decongestion (odds ratio 4.44; 95% confidence interval 0.81–24.3; P=0.086).

Conclusions: Plasma AVP appears to be a physiologically important mediator of SCr fluctuations under decongestion treatment in HF patients.

Decongestion discriminates risk for one-year mortality in patients with improving renal function in acute heart failure

AIMS

Improving renal function (IRF) is paradoxically associated with worse outcomes in acute heart failure (AHF), but outcomes may differ based on response to decongestion. We explored if the relationship of IRF with mortality in hospitalized AHF patients differs based on successful decongestion.

METHODS AND RESULTS

We evaluated 760 AHF patients from AKINESIS for the relationship between IRF, change in B-type natriuretic peptide (BNP), and 1-year mortality. IRF was defined as a ≥20% increase in estimated glomerular filtration rate (eGFR) relative to admission. Adequate decongestion was defined as a ≥40% decrease in last measured BNP relative to admission. IRF occurred in 22% of patients who had a mean age of 69 years, 58% were men, 72% were white, and median admission eGFR was 49 mL/min/1.73 m² . IRF patients had more severe heart failure reflected by lower admission eGFR, higher blood urea nitrogen, lower systolic blood pressure, lower sodium, and higher use of inotropes. IRF patients had higher 1-year mortality (25%) than non-IRF patients (15%) (P < 0.01). However, this relationship differed by BNP trajectory (P-interaction = 0.03). When stratified by BNP change, non-IRF patients and IRF patients with decreasing BNP had lower 1-year mortality than either non-IRF and IRF patients without decreasing BNP. However, in multivariate analysis, IRF was not associated with mortality [adjusted hazard ratio (HR) 1.0, 95% confidence interval (CI) 0.7-1.5] while BNP was (adjusted HR 0.5, 95% CI 0.3-0.7). When IRF was evaluated as transiently occurring or persisting at discharge, again only BNP change was significantly associated with mortality.

CONCLUSION

Improving renal function is associated with mortality in AHF but not independent of other variables and congestion status. Achieving adequate decongestion, as reflected by lower BNP, in AHF is more strongly associated with mortality than IRF.

Diuresis-Related Weight Loss Reflects Interstitial Compartment Decongestion with Minimal Impact on Intravascular Volume Expansion or Outcomes in Post-Acute Heart Failure: Metrics of Decongestion and Volume Status

BACKGROUND

Findings from heart failure (HF) studies linking diuresis-related weight loss to clinical decongestion and outcomes are mixed. Differential responses of interstitial and intravascular volume compartments to diuretic therapy and heterogeneity in volume profiles may confound the clinical interpretation of weight loss in patients with HF.

METHODS AND RESULTS

Data were prospectively collected in hospitalized patients requiring diuresis. Plasma volume (PV) was measured using I-131-labelled albumin indicator-dilution methodology. The cohort was stratified by tertiles of weight loss and analyzed for interstitial fluid loss relative to changes in PV and HF-related morality or first rehospitalization. Among 92 patients, the admission PV was expanded +42% (4.7 ± 1.2 L) above normal with significant variability (14% normal PV, 18% mild-moderate expansion, and 68% with large PV expansion [>+25% above normal]). With diuresis there were proportional decreases in interstitial volume (-6.5 ± 4.4%) and PV (-7.5 ± 11%); however, absolute decreases in the PV (-254 mL, interquartile range -11 to -583 mL) were less than 10% of interstitial volume loss (-5040 mL, interquartile range -2800 to -7989 mL); greater interstitial fluid loss did not translate into better outcomes (log-rank P = .430).

CONCLUSIONS

Diuresis-related decreases in weight reflect fluid loss from the interstitial compartment with only minor changes in the PV and without an impact on outcomes. Further, the degree of PV expansion at hospital admission does not drive the magnitude of the diuresis response, even with a wide spectrum of body weights; interstitial fluid overload is preferentially targeted and PV relatively preserved. Therefore, greater interstitial fluid loss reflects clinical decongestion, but not better outcomes, and a limited association with intravascular volume profiles potentially confounding weight loss as a prognostic metric in HF.

Prognostic significance of acute kidney injury and small increases in creatinine concentration during acute decompensation of heart failure

BACKGROUND

Diagnosis of acute kidney injury (AKI) during acute decompensations of heart failure (ADHF) remain challenging. We analysed the incidence and prognosis of AKI, and the significance of small increases of creatinine, during ADHF and after stabilization.

PATIENTS AND METHODS

Patients admitted for ADHF were prospectively included. Creatinine was measured at admission, 48h thereafter and 24h before discharge. AKI was diagnosed when creatinine increased≥50% in 7 days (RIFLE criteria) or≥0.3mg/dL in 48h (AKIN criteria) during admission. Changes between baseline creatinine (measured within 3-month before admission) and one month after discharge were assessed, to seek for residual impairment of renal function and its significance.

RESULTS

Two hundred and four patients were included. Incidence of AKI was 28.4% (n=58). Creatinine peaked by day 5 in patients with AKI vs. non-AKI (1.9 vs. 1.1mg/dL; P<.000) and remained significantly higher among patients with AKI 3 months after discharge (increase of 20 vs. 4%; P=.013). Twelve-months mortality was associated with increases in cystatin C, NT-proBNP and AKI (15.5 vs. 44.8%, P<.000), being the latter the most powerful independent predictor of death ?Exp(B)=5.34; P=.009?. Minor increases in creatinine (20% or 0.2mg/dL) during admission associated lesser 12-months survival (P=.033 and P=.019, respectively). Increases in creatinine≥10% between baseline and one month after discharge are associated with higher mortality (12.6 vs. 22.5%, P=.044).

CONCLUSIONS

AKI is a strong predictor of mortality after ADHF. Minor increments in creatinine concentrations, below the accepted threshold for AKI definition, are prognostically meaningful.

Congestion and Diuretic Resistance in Acute or Worsening Heart Failure

Hospitalisation for acute heart failure (AHF) is associated with high mortality and high rehospitalisation rates. In the absence of evidence-based therapy, treatment is aimed at stabilisation and symptom relief. The majority of AHF patients have signs and symptoms of fluid overload, and, therefore, decongestion is the number one treatment goal. Diuretics are the cornerstone of therapy in AHF, but the treatment effect is challenged by diuretic resistance and poor diuretic response throughout the spectrum of chronic to worsening to acute to post-worsening HF. Adequate dosing and monitoring and evaluation of diuretic effect are important for treatment success. Residual congestion at discharge is a strong predictor of worse outcomes. Therefore, achieving euvolaemia is crucial despite transient worsening renal function.

Acute Kidney Function Declines in the Context of Decongestion in Acute Decompensated Heart Failure

OBJECTIVES

This study aimed to examine whether incorporation of a comprehensive set of measures of decongestion modifies the association of acute declines in kidney function with outcomes.

BACKGROUND

In-hospital acute declines in kidney function occur in approximately 20% to 30% of patients admitted with acute decompensated heart failure (ADHF) and may be associated with adverse outcomes.

METHODS

Using data from EVEREST (Efficacy of Vasopressin Antagonism in Heart Failure Outcome Study With Tolvaptan), we used multivariable Cox regression models to evaluate the association between in-hospital changes in estimated glomerular filtration rate (eGFR) with death and a composite outcome of cardiovascular death and hospitalization for heart failure. We evaluated eGFR declines within the context of changes in markers of volume overload including b-type natriuretic peptide (BNP), N-terminal prohormone of B-type natriuretic peptide (NT-proBNP), and weight, as well as changes in measures of hemoconcentration including hematocrit, albumin, and total protein.

RESULTS

Among 3,715 patients over a median follow-up of 9.9 months, every 30% decline in eGFR was associated with higher risk of both death (hazard ratio [HR]: 1.19; 95% confidence interval [CI]: 1.07 to 1.31) and the composite outcome (HR: 1.09; 95% CI: 1.01 to 1.18) in adjusted models. The acute decline in eGFR was no longer associated with higher risk of either outcome as long as there was evidence of decongestion, either by declines in BNP, NT-proBNP, or weight or by increases in hematocrit, albumin or total protein. Interaction testing between decline in eGFR and changes in hematocrit, albumin, and total protein was statistically significant (p interaction of <0.01 for death and p interaction of ≤0.01 for composite for all 3 biomarkers). Interaction between change in eGFR and changes in BNP (p interaction = 0.07 for death; p interaction = 0.08 for composite), NT-proBNP (p interaction = 0.15 for death; p interaction = 0.18 for composite) and weight (p interaction = 0.13 for death; p interaction = 0.19 for composite) did not meet statistical significance.

CONCLUSIONS

Overall, acute declines in eGFR are associated with adverse outcomes, with evidence of modification by changes in markers of decongestion, suggesting that they are no longer associated with adverse outcomes if these markers are concomitantly improving.

Incorporation of renal function in mortality risk assessment for pulmonary arterial hypertension

BACKGROUND

Risk assessment is important for prognostication and individualized treatment decisions for patients with pulmonary arterial hypertension (PAH). The purpose was (1) to compare contemporary risk assessment tools and (2) to determine the prognostic significance of risk parameters of kidney function and whether they can further improve risk prediction for patients with PAH.

METHODS

We identified a cohort of treatment-naive patients (n = 211) who received an incident diagnosis of PAH at the University of Ottawa Heart Institute. Using demographics, disease characteristics, and hemodynamic data at diagnosis, we categorized patients as low, intermediate, or high risk according to current European guidelines (European Society of Cardiology [ESC]) and registry to evaluate early and long-term pulmonary arterial hypertension disease management (REVEAL) risk scores. The primary end-point was transplant-free survival (TFS).

RESULTS

Patients were predominantly women (64.6%) with World Health Organization function Class III symptoms (66.5%). The median TFS was 7.09 years. There was little agreement between ESC- and REVEAL-based risk estimates (weighted kappa = 0.21-0.34). Although both the ESC (log-rank, p = 0.0002) and REVEAL algorithms stratified TFS risk (p < 0.0001), the REVEAL score provided superior discrimination (C-statistic = 0.70 vs 0.59, p = 0.004). Renal function at diagnosis (p < 0.0001) and Δ renal function at 6 months (p < 0.0001) were identified as novel risk parameters and served to reclassify some patients in the intermediate-risk category to a lower or higher risk stratum (p < 0.0001).

CONCLUSION

REVEAL-based strategies provide superior TFS risk discrimination to ESC/European Respiratory Society-based approaches. However, the classification of intermediate-risk patients varied significantly across tools. We demonstrate the importance of renal function, which further improved the stratification of risk in patients with PAH, particularly in patients who are considered intermediate risk.

Improved cardiac and venous pressures during hospital stay in patients with acute heart failure: an echocardiography and biomarkers study

Aims

Changes in echocardiographic parameters and biomarkers of cardiac and venous pressures or estimated plasma volume during hospitalization associated with decongestive treatments in acute heart failure (AHF) patients with either preserved left ventricular ejection fraction (LVEF) (HFPEF) or reduced LVEF (HFREF) are poorly assessed.

Methods and results

From the metabolic road to diastolic heart failure: diastolic heart failure (MEDIA‐DHF) study, 111 patients were included in this substudy: 77 AHF (43 HFPEF and 34 HFREF) and 34 non‐cardiac dyspnea patients. Echocardiographic measurements and blood samples were obtained within 4 h of presentation at the emergency department and before hospital discharge. In AHF patients, echocardiographic indices of cardiac and venous pressures, including inferior vena cava diameter [from 22 (16–24) mm to 13 (11–18) mm, P = 0.009], its respiratory variability [from 32 (8–44) % to 43 (29–70) %, P = 0.04], medial E/e' [from 21.1 (15.8–29.6) to 16.6 (11.7–24.3), P = 0.004], and E wave deceleration time [from 129 (105–156) ms to 166 (128–203) ms, P = 0.003], improved during hospitalization, similarly in HFPEF and HFREF patients. By contrast, no changes were seen in non‐cardiac dyspnea patients. In AHF patients, all plasma biomarkers of cardiac and venous pressures, namely B‐type natriuretic peptide [from 935 (514–2037) pg/mL to 308 (183–609) pg/mL, P < 0.001], mid‐regional pro‐atrial natriuretic peptide [from 449 (274–653) pmol/L to 366 (242–549) pmol/L, P < 0.001], and soluble CD‐146 levels [from 528 (406–654) ng/mL to 450 (374–529) ng/mL, P = 0.003], significantly decreased during hospitalization, similarly in HFPEF and HFREF patients. Echocardiographic parameters of cardiac chamber dimensions [left ventricular end‐diastolic volume: from 120 (76–140) mL to 118 (95–176) mL, P = 0.23] and cardiac index [from 2.1 (1.6–2.6) mL/min/m² to 1.9 (1.4–2.4) mL/min/m², P = 0.55] were unchanged in AHF patients, except tricuspid annular plane systolic excursion (TAPSE) that improved during hospitalization [from 16 (15–19) mm to 19 (17–21) mm, P = 0.04]. Estimated plasma volume increased in both AHF [from 4.8 (4.2–5.6) to 5.1 (4.4–5.8), P = 0.03] and non‐cardiac dyspnea patients (P = 0.01). Serum creatinine [from 1.18 (0.90–1.53) to 1.19 (0.86–1.70) mg/dL, P = 0.89] and creatinine‐based estimated glomerular filtration rate [from 59 (40–75) mL/min/1.73m² to 56 (38–73) mL/min/1.73m², P = 0.09] were similar, while plasma cystatin C [from 1.50 (1.20–2.27) mg/L to 1.78 (1.33–2.59) mg/L, P < 0.001] and neutrophil gelatinase associated lipocalin (NGAL) [from 127 (95–260) ng/mL to 167 (104–263) ng/mL, P = 0.004] increased during hospitalization in AHF.

Conclusions

Echocardiographic parameters and plasma biomarkers of cardiac and venous pressures improved during AHF hospitalization in both acute HFPEF and HFREF patients, while cardiac chamber dimensions, cardiac output, and estimated plasma volume showed minimal changes.

B-type natriuretic peptide trend predicts clinical significance of worsening renal function in acute heart failure

AIMS

In acute heart failure (AHF), relationships between changes in B-type natriuretic peptide (BNP) and worsening renal function (WRF) and its prognostic implications have not been fully determined. We investigated the relationship between WRF and a decrease in BNP with in-hospital and 1-year mortality in AHF.

METHODS AND RESULTS

The Acute Kidney Injury NGAL Evaluation of Symptomatic heart faIlure Study (AKINESIS) was a prospective, international, multicentre study of AHF patients. Severe WRF (sWRF) was a sustained increase of ≥44.2 μmol/L (0.5 mg/dL) or ≥50% in creatinine, non-severe WRF (nsWRF) was a non-sustained increase of ≥26.5 μmol/L (0.3 mg/dL) or ≥50% in creatinine, and WRF with clinical deterioration was nsWRF with renal replacement therapy, inotrope use, or mechanical ventilation. Decreased BNP was defined as a ≥30% reduction in the last measured BNP compared to admission BNP. Among 814 patients, the incidence of WRF was not different between patients with or without decreased BNP (nsWRF: 33% vs. 31%, P = 0.549; sWRF: 11% vs. 9%, P = 0.551; WRF with clinical deterioration: 8% vs. 10%, P = 0.425). Decreased BNP was associated with better in-hospital and 1-year mortality regardless of WRF, while WRF was associated with worse outcomes only in patients without decreased BNP. In multivariate Cox regression analysis, decreased BNP, sWRF, and WRF with clinical deterioration were significantly associated with 1-year mortality.

CONCLUSIONS

Decreased BNP was associated with better in-hospital and long-term outcomes. WRF was only associated with adverse outcomes in patients without decreased BNP.

Predictors of responders for low-dose carperitide monotherapy in patients with acute heart failure

Human atrial natriuretic peptide, known as carperitide, is approved for early relief of dyspnea in patients with acute heart failure (AHF). However, the diuretic effect of carperitide is sometimes insufficient for controlling volume overload. We investigated predictors for the carperitide response in patients with AHF. Forty-seven patients (age: 74 ± 10 years; left ventricular ejection fraction: 42.0% ± 15.9%) with AHF were enrolled and treated with carperitide monotherapy at a dose of 0.0125 μg/kg/min. Patients without sufficient diuresis (< 60 ml/h) or improvement of symptoms by 4 h after carperitide administration, despite increasing to twice the dose of carperitide and adding another agent, were defined as non-responders. Twenty-four (51%) patients were defined as responders and treated with low-dose carperitide monotherapy on the first day. Multiple logistic regression analysis showed that the response to carperitide monotherapy was independently predicted by serum creatinine levels and systolic blood pressure (SBP) on admission. The area under the receiver-operating characteristic curve for predicting the response to carperitide by SBP was 0.808 (95% confidence interval [0.686-0.930], sensitivity: 83.3%, specificity: 65.2%, cutoff value: 135 mmHg). Four (8.5%) patients developed asymptomatic transient hypotension. Worsening renal function occurred within 3 days of admission in three (6.4%) patients who received low-dose carperitide therapy. SBP and serum creatinine levels on admission might be useful for predicting the diuretic response to low-dose carperitide monotherapy in patients with AHF. Initial use of low-dose carperitide therapy does not have adverse effects on renal function.

Impact of renal dysfunction on the management and outcome of acute heart failure: results from the French prospective, multicentre, DeFSSICA survey

OBJECTIVES

Cardiorenal syndrome (CRS) is the combination of acute heart failure syndrome (AHF) and renal dysfunction (creatinine clearance (CrCl) ≤60 mL/min). Real-life data were used to compare the management and outcome of AHF with and without renal dysfunction.

DESIGN

Prospective, multicentre.

SETTING

Twenty-six academic, community and regional hospitals in France.

PARTICIPANTS

507 patients with AHF were assessed in two groups according to renal function: group 1 (patients with CRS (CrCl ≤60 mL/min): n=335) and group 2 (patients with AHF with normal renal function (CrCl >60 mL/min): n=172).

RESULTS

Differences were observed (group 1 vs group 2) at admission for the incidence of chronic heart failure (56.42% vs 47.67%), use of furosemide (60.9% vs 52.91%), insulin (15.52% vs 9.3%) and amiodarone (14.33% vs 4.65%); additionally, more patients in group 1 carried a defibrillator (4.78% vs 0%), had ≥2 hospitalisations in the last year (15.52% vs 5.81%) and were under the care of a cardiologist (72.24% vs 61.63%). Clinical signs were broadly similar in each group. Brain-type natriuretic peptide (BNP) and BNP prohormone were higher in group 1 than group 2 (1157.5 vs 534 ng/L and 5120 vs 2513 ng/mL), and more patients in group 1 were positive for troponin (58.2% vs 44.19%), had cardiomegaly (51.04% vs 37.21%) and interstitial opacities (60.3% vs 47.67%). The only difference in emergency treatment was the use of nitrates, (higher in group 1 (21.9% vs 12.21%)). In-hospital mortality and the percentage of patients still hospitalised after 30 days were similar between groups, but the median stay was longer in group 1 (8 days vs 6 days).

CONCLUSIONS

Renal impairment in AHF should not limit the use of loop diuretics and/or vasodilators, but early assessment of pulmonary congestion and close monitoring of the efficacy of conventional therapies is encouraged to allow rapid and appropriate implementation of alternative therapies if necessary.

Utility of Novel Cardiorenal Biomarkers in the Prediction and Early Detection of Congestive Kidney Injury Following Cardiac Surgery

Acute Kidney Injury (AKI) in the context of right ventricular failure (RVF) is thought to be largely congestive in nature. This study assessed the utility of biomarkers high sensitivity cardiac troponin T (hs-cTnT), N-Terminal Pro-B-Type Natriuretic Peptide (NT-proBNP), and neutrophil gelatinase-associated lipocalin (NGAL) for prediction and early detection of congestive AKI (c-AKI) following cardiac surgery. This prospective nested case-control study recruited 350 consecutive patients undergoing elective cardiac surgery requiring cardiopulmonary bypass. Cases were patients who developed (1) AKI (2) new or worsening RVF, or (3) c-AKI. Controls were patients free of these complications. Biomarker levels were measured at baseline after anesthesia induction and immediately postoperatively. Patients with c-AKI had increased mean duration of mechanical ventilation and length of stay in hospital and in the intensive care unit (p < 0.01). For prediction of c-AKI, baseline NT-proBNP yielded an area under the curve (AUC) of 0.74 (95% CI, 0.60–0.89). For early detection of c-AKI, postoperative NT-proBNP yielded an AUC of 0.78 (0.66–0.91), postoperative hs-cTnT yielded an AUC of 0.75 (0.58–0.92), and ∆hs-cTnT yielded an AUC of 0.80 (0.64–0.96). The addition of baseline creatinine to ∆hs-cTnT improved the AUC to 0.87 (0.76–0.99), and addition of diabetes improved the AUC to 0.93 (0.88–0.99). Δhs-cTnT alone, or in combination with baseline creatinine or diabetes, detects c-AKI with high accuracy following cardiac surgery.

Practical management of concomitant acute heart failure and worsening renal function in the emergency department

Worsening renal function (i.e. any increase in creatinine or decrease in the estimated glomerular filtration rate) is common in patients admitted for acute heart failure in the emergency department. Although worsening renal function (WRF) has been associated with the occurrence of dismal outcomes, this only appears to be the case when associated with clinical deterioration. However, if the clinical status of the patient is improving, a certain increase in serum creatinine may be acceptable. This WRF, which is not associated with clinical deterioration or adverse outcomes (e.g. during treatment up-titration), has been referred to as 'pseudo-WRF' and should not detract clinicians from targeting 'guideline-recommended' therapies. This is an important message for emergency physicians to pursue diuretics as long as signs of pulmonary congestion persist to improve the clinical status of the patient. In the present review, we aim to provide clinicians in acute settings with an integrative and comprehensive approach to cardiorenal interactions in acute heart failure.

Readmission rate after ultrafiltration in acute decompensated heart failure: a systematic review and meta-analysis

Significance of ultrafiltration in acute decompensated heart failure remains unclear. We performed meta-analysis to determine its role in reducing readmissions after acute decompensated heart failure. MEDLINE was searched using PUBMED from inception to March 22, 2017 for prospective randomized control trials comparing ultrafiltration to diuretics in acute decompensated heart failure. Five hundred ninety studies were found; nine studies with 820 patients were included. Studies with renal replacement therapy bar ultrafiltration, chronic decompensated heart failure, and non-English language were excluded. RevMan Version 5.3 was used for analysis. The primary outcomes analyzed were cumulative and 90 days readmissions secondary to heart failure and all-cause readmissions. Baseline characteristics were similar. One hundred eighty-eight patients were readmitted with heart failure, 77 vs 111 favoring ultrafiltration; risk ratio (RR) = 0.71 (95% confidence interval (CI), 0.49-1.02, p = 0.07, I ²  = 47%). Ninety days readmissions were 43 vs 67 favoring ultrafiltration; RR = 0.65 (95%CI, 0.47-0.90, p = 0.01, I ²  = 0%). Ultrafiltration showed significantly higher fluid removal and weight loss. Hypotension was common in ultrafiltration (24 vs 13, OR = 2.06, 95%CI = 0.98-4.32, p = 0.06, I ²  = 0%). Ultrafiltration showed reduced 90 days heart failure readmissions and trend towards reduced cumulative hospital readmissions. Renal and cardiovascular outcomes and hospital stay were similar.

Effects of early diuretic response to carperitide in acute decompensated heart failure treatment: A single-center retrospective study

Background

Diuretic response is a strong predictor of outcome for admitted patients of acute decompensated heart failure (ADHF). However, little is known about the effects of early diuretic response to carperitide.

Methods

We retrospectively analyzed records of 85 patients hospitalized for ADHF who received carperitide as initial treatment and <40 mg furosemide during the early period. The eligible patients were divided into good diuretic responder (GR) group and poor diuretic responder (PR) group on the basis of median urinary volume.

Results

The PR group demonstrated older age, lower body mass index (BMI), lower estimated glomerular filtration rate, and higher blood urea nitrogen (BUN) level, left ventricular ejection fraction, and β-blockers prescribed at baseline than the GR group. The incidence of worsening renal function (WRF) was significantly higher in the PR group than in the GR group. There was no correlation between early intravenous furosemide dose and urinary volume (Spearman correlation, ρ = 0.111, p = 0.312). Multivariate analysis showed that the statistically significant independent factors associated with poor diuretic response to carperitide were BMI (Odds ratio (OR) = 0.82, 95% confidence interval (CI) 0.68–0.94, p = 0.004) and BUN (OR = 1.07, 95%CI 1.01–1.15, p = 0.018). Kaplan–Meier analysis indicated a lower event-free rate in the PR group than in the GR group (log-rank, p = 0.007).

Conclusions

BMI and BUN levels on admission were significant determinants of early poor diuretic response to carperitide. Early poor diuretic response to carperitide was associated with future poor outcomes.

Pulmonary Catherization Data Correlate Poorly with Renal Function in Heart Failure

BACKGROUND

The mechanisms of renal dysfunction in heart failure are poorly understood. We chose to explore the relationship of cardiac filling pressures and cardiac index (CI) in relation to renal dysfunction in advanced heart failure.

OBJECTIVES

To determine the relationship between renal function and cardiac filling pressures using the United Network of Organ Sharing (UNOS) pulmonary artery catherization registry.

METHODS

Patients over the age of 18 years who were listed for single-organ heart transplantation were included. Exclusion criteria included a history of mechanical circulatory support, previous transplantation, any use of renal replacement therapy, prior history of malignancy, and cardiac surgery, amongst others. Correlations between serum creatinine (SCr) and CI, pulmonary capillary wedge pressure (PCWP), pulmonary artery systolic pressure (PASP), and pulmonary artery diastolic pressure (PADP) were assessed by Pearson correlation coefficients and simple linear regression coefficients.

RESULTS

Pearson correlation coefficients between SCr and PCWP, PASP, and PADP were near zero with values of 0.1, 0.07, and 0.08, respectively (p < 0.0001). A weak negative correlation coefficient between SCr and CI was found (correlation coefficient, -0.045, p = 0.027). In a subgroup of young patients unlikely to have noncardiac etiologies, no significant correlations between these values were identified.

CONCLUSION

These findings suggest that, as assessed by pulmonary artery catherization, none of the factors - PCWP, PASP, PADP, or CI - play a prominent role in cardiorenal syndromes.

The Patterns, Risk Factors, and Prediction of Progression in Chronic Kidney Disease: A Narrative Review

Chronic kidney disease (CKD) is a global public health problem that is associated with excess morbidity, mortality, and health resource utilization. The progression of CKD is defined by a decrease in glomerular filtration rate and leads to a variety of metabolic abnormalities including acidosis, hypertension, anemia, and mineral bone disorder. Lower glomerular filtration rate also bears a strong relationship with an increased risk of cardiovascular events, end-stage renal disease, and death. Patterns of CKD progression include linear and nonlinear trajectories, but kidney function can remain stable for years in some individuals. Addressing modifiable risk factors for the progression of CKD is needed to attenuate its associated morbidity and mortality. Developing effective risk prediction models for CKD progression is critical to identify patients who are more likely to benefit from interventions and more intensive monitoring. Accurate risk-prediction algorithms permit systems to best align health care resources with risk to maximize their effects and efficiency while guiding overall decision making.

Pathophysiology of cardiorenal syndrome in patients with heart failure: potential therapeutic targets

Despite the development of pharmacological inventions and new nonpharmacological techniques to prevent and treat heart failure (HF), the mortality rate in patients with symptomatic HF remains high. To conquer these difficulties, the pathophysiology of HF should be considered within a wide range of views. Given the diverse mechanisms of HF pathophysiology, renal and cardiac functions have close and complementary interconnections. Recent studies have suggested that communication between the kidney and heart through bidirectional pathways causes significant pathological changes. This review summarizes the pathophysiology of cardiorenal syndrome (CRS) from three different viewpoints, namely, underlying chronic kidney disease, worsening renal function during hospitalization due to HF, and resistance to diuretics. We also summarize the presently available data on the pathophysiology of CRS, identify the challenges associated with some clinical approaches, and explore the potential therapeutic target for CRS.

Usefulness of the Combination of In-Hospital Poor Diuretic Response and Systemic Congestion to Predict Future Cardiac Events in Patients With Acute Decompensated Heart Failure

We aimed to (1) investigate the relation between diuretic response (DR) with or without systemic congestion and prognosis and (2) explore the potential predictors of poor DR for risk stratification in patients with acute decompensated heart failure (ADHF). We enrolled 186 consecutive patients hospitalized for ADHF. The DR was defined as (body weight at discharge - body weight at admission)/40 mg furosemide or equivalent loop diuretic dose. Systemic congestion on admission was simply evaluated by the presence of leg edema or jugular venous distention. All patients were divided into 4 groups based on the median of DR (-0.50 kg/40 mg) and the status of systemic congestion; GR/C (good DR with systemic congestion, n = 66), GR/N (good DR without systemic congestion, n = 27), PR/C (poor DR with systemic congestion, n = 48); and PR/N (poor DR without systemic congestion, n = 45). The composite outcome was defined as cardiac death and rehospitalization for worsening heart failure. In survival analysis, the cardiac event-free rate in PR/C was significantly lower than that in any other groups (log-rank, p <0.001), and PR/C was an independent predictor of cardiac events (hazard ratio 2.17, p = 0.016). In conclusion, the combination of in-hospital poor DR, characterized by previous ischemic heart disease, and prehospital dose of daily loop diuretics, and systemic congestion provides a risk stratification for future cardiac events in patients with ADHF.

Renal function assessment in heart failure

Renal function is one of the most consistent prognostic determinants in heart failure. The prognostic information it provides is independent of the ejection fraction and functional status. This article reviews the various renal function assessment measures, with special emphasis on the fact that the patient's clinical situation and response to the heart failure treatment should be considered for the correct interpretation of the results. Finally, we review the literature on the performance of tubular damage biomarkers.

Progression of Renal Impairment and Chronic Kidney Disease in Chronic Heart Failure: An Analysis From GISSI-HF

BACKGROUND

Data on the natural change in renal function in patients with chronic heart failure (HF) are limited.

METHODS AND RESULTS

Estimated glomerular filtration rate (eGFR) was assessed over 36 months in 6934 patients included in the GISSI-HF study. Associations from baseline, changes in renal function, and occurrence of cardiovascular death or HF hospitalization were assessed. Mean age was 67 years, mainly men (78%), and mean eGFR was 68 mL • min^-1 • 1.73 m^-2. Change in eGFR in the 1st year was -1.5 ± 16 mL • min^-1 • 1.73 m^-2, and over 36 months it was -3.7 ± 18 mL • min^-1 • 1.73 m^-2. Over the latter period, only 25% deteriorated ≥1 Kidney Disease Outcomes Quality Initiatives (KDOQI) class of chronic kidney disease (CKD). Fifteen percent of patients had >15 mL • min^-1 • 1.73 m^-2 decrease in eGFR in the 1st 12 months. Lower eGFR was associated with outcome: hazard ratio (HR) 1.10, 95% confidence interval (CI) 1.08-1.10 (P < .001) per 10 mL • min^-1 • 1.73 m^-2 decrease, as well as every 10 mL • min^-1 • 1.73 m^-2 decrease over the 1st year (HR 1.10, 95% CI 1.04-1.17; P < .001). A deterioration in eGFR >15 mL • min^-1 • 1.73 m^-2 in the 1st year showed the highest risk of events (HR 1.22, 95% CI 1.10-1.36; P < .001).

CONCLUSIONS

Mean decrease in renal function over time in patients with chronic HF was modest. Only 25% deteriorated ≥1 KDOQI class of CKD after 3 years. Any decrease in eGFR over time was associated with strongly increased event rates.

Hemodynamic and neurochemical determinates of renal function in chronic heart failure

Abnormal renal function is common in acute and chronic congestive heart failure (CHF) and is related to the severity of congestion. However, treatment of congestion often leads to worsening renal function. Our objective was to explore basal determinants of renal function and their response to hemodynamic interventions. Thirty-seven patients without CHF and 59 patients with chronic CHF (ejection fraction; 23 ± 8%) underwent right heart catheterization, measurements of glomerular filtration rate (GFR; inulin) and renal plasma flow (RPF; para-aminohippurate), and radiotracer estimates of renal sympathetic activity. A subset (26 without, 36 with CHF) underwent acute pharmacological intervention with dobutamine or nitroprusside. We explored the relationship between baseline and drug-induced hemodynamic changes and changes in renal function. In CHF, there was an inverse relationship among right atrial mean pressure (RAM) pressure, RPF, and GFR. By contrast, mean arterial pressure (MAP), cardiac index (CI), and measures of renal sympathetic activity were not significant predictors. In those with CHF there was also an inverse relationship among the drug-induced changes in RAM as well as pulmonary artery mean pressure and the change in GFR. Changes in MAP and CI did not predict the change in GFR in those with CHF. Baseline values and changes in RAM pressure did not correlate with GFR in those without CHF. In the CHF group there was a positive correlation between RAM pressure and renal sympathetic activity. There was also an inverse relationship among RAM pressure, GFR, and RPF in patients with chronic CHF. The observation that acute reductions in RAM pressure is associated with an increase in GFR in patients with CHF has important clinical implications.

Intensification of Medication Therapy for Cardiorenal Syndrome in Acute Decompensated Heart Failure

BACKGROUND

Worsening renal function in heart failure may be related to increased venous congestion, decreased cardiac output, or both. Diuretics are universally used in acute decompensated heart failure, but they may be ineffective and may lead to azotemia. We aimed to compare the decongestive properties of a urine output-guided diuretic adjustment and standard therapy for the management of cardiorenal syndrome in acute decompensated heart failure.

METHODS AND RESULTS

Data were pooled from subjects randomized to the stepwise pharmacologic care algorithm (SPCA) in the CARRESS-HF trial and those who developed cardiorenal syndrome (rise in creatinine >0.3 mg/dL) in the DOSE-AHF and ROSE-AHF trials. Patients treated with SPCA (n = 94) were compared with patients treated with standard decongestive therapy (SDT) that included intravenous loop diuretic use (DOSE-AHF and ROSE-AHF; n = 107) at the time of cardiorenal syndrome and followed for net fluid balance, weight loss, and changing renal function. The SPCA group had higher degrees of jugular venous pressure (P < .0001) at the time of cardiorenal syndrome. The group that received SPCA had more weight change (-3.4 ± 5.2 lb) and more net fluid loss (1.705 ± 1.417 L) after 24 hours than the SDT group (-0.8 ± 3.4 lb and 0.892 ± 1.395 L, respectively; P < .001 for both) with a slight improvement in renal function (creatinine change -0.1 ± 0.3 vs 0.0 ± 0.3 mg/dL, respectively; P = .03).

CONCLUSIONS

Compared with SDT, patients who received an intensification of medication therapy for treating persisting congestion had greater net fluid and weight loss without being associated with renal compromise.

Long-term remote organ consequences following acute kidney injury

Acute kidney injury (AKI) has been a global health epidemic problem with soaring incidence, increased long-term risks for multiple comorbidities and mortality, as well as elevated medical costs. Despite the improvement of patient outcomes following the advancements in preventive and therapeutic strategies, the mortality rates among critically ill patients with AKI remain as high as 40–60 %. The distant organ injury, a direct consequence of deleterious systemic effects, following AKI is an important explanation for this phenomenon. To date, most evidence of remote organ injury in AKI is obtained from animal models. Whereas the observations in humans are from a limited number of participants in a relatively short follow-up period, or just focusing on the cytokine levels rather than clinical solid outcomes. The remote organ injury is caused with four underlying mechanisms: (1) “classical” pattern of acute uremic state; (2) inflammatory nature of the injured kidneys; (3) modulating effect of AKI of the underlying disease process; and (4) healthcare dilemma. While cytokines/chemokines, leukocyte extravasation, oxidative stress, and certain channel dysregulation are the pathways involving in the remote organ damage. In the current review, we summarized the data from experimental studies to clinical outcome studies in the field of organ crosstalk following AKI. Further, the long-term consequences of distant organ-system, including liver, heart, brain, lung, gut, bone, immune system, and malignancy following AKI with temporary dialysis were reviewed and discussed.

Influence of Titration of Neurohormonal Antagonists and Blood Pressure Reduction on Renal Function and Decongestion in Decompensated Heart Failure

BACKGROUND

Reduction in systolic blood pressure (SBP reduction) during the treatment of acute decompensated heart failure is strongly and independently associated with worsening renal function. Our objective was to determine whether SBP reduction or titration of oral neurohormonal antagonists during acute decompensated heart failure treatment negatively influences diuresis and decongestion.

METHODS AND RESULTS

SBP reduction was evaluated from admission to discharge in consecutive acute decompensated heart failure admissions (n=656). Diuresis and decongestion were examined across a range of parameters, such as diuretic efficiency, fluid output, hemoconcentration, and diuretic dose. The average reduction in SBP was 14.4 ± 19.4 mm Hg, and 77.6% of the population had discharge SBP lower than admission. SBP reduction was strongly associated with worsening renal function (odds ratio, 1.9; 95% confidence interval, 1.2-2.9; P=0.004), a finding that persisted after adjusting for parameters of diuresis and decongestion (odds ratio, 2.0; 95% confidence interval, 1.3-3.2; P=0.002). However, SBP reduction did not negatively affect diuresis or decongestion (P ≥ 0.25 for all parameters). Uptitration of neurohormonal antagonists occurred in >50% of admissions and was associated with a modest additional reduction in blood pressure (≤ 5.6 mm Hg). Notably, worsening renal function was not increased, and diuretic efficiency was significantly improved with the uptitration of neurohormonal antagonists.

CONCLUSIONS

Despite a higher rate of worsening renal function, blood pressure reduction was not associated with worsening of diuresis or decongestion. Furthermore, titration of oral neurohormonal antagonists was actually associated with improved diuresis in this cohort. These results provide reassurance that the guideline-recommended titration of chronic oral medication during acute decompensated heart failure hospitalization may not be antagonistic to the short-term goal of decongestion.

Focus on renal congestion in heart failure

Hospitalizations due to heart failure are increasing steadily despite advances in medicine. Patients hospitalized for worsening heart failure have high mortality in hospital and within the months following discharge. Kidney dysfunction is associated with adverse outcomes in heart failure patients. Recent evidence suggests that both deterioration in kidney function and renal congestion are important prognostic factors in heart failure. Kidney congestion in heart failure results from low cardiac output (forward failure), tubuloglomerular feedback, increased intra-abdominal pressure or increased venous pressure. Regardless of the cause, renal congestion is associated with increased morbidity and mortality in heart failure. The impact on outcomes of renal decongestion strategies that do not compromise renal function should be explored in heart failure. These studies require novel diagnostic markers that identify early renal damage and renal congestion and allow monitoring of treatment responses in order to avoid severe worsening of renal function. In addition, there is an unmet need regarding evidence-based therapeutic management of renal congestion and worsening renal function. In the present review, we summarize the mechanisms, diagnosis, outcomes, prognostic markers and treatment options of renal congestion in heart failure.

Pathophysiology of acute heart failure: a world to know

Our understanding of the pathophysiological mechanisms of heart failure (HF) has changed considerably in recent years, progressing from a merely haemodynamic viewpoint to a concept of systemic and multifactorial involvement in which numerous mechanisms interact and concatenate. The effects of these mechanisms go beyond the heart itself, to other organs of vital importance such as the kidneys, liver and lungs. Despite this, the pathophysiology of acute HF still has aspects that elude our deeper understanding. Haemodynamic overload, venous congestion, neurohormonal systems, natriuretic peptides, inflammation, oxidative stress and its repercussion on cardiac and vascular remodelling are currently considered the main players in acute HF. Starting with the concept of acute HF, this review provides updates on the various mechanisms involved in this disease.