Circulatory response to fluid overload removal by extracorporeal ultrafiltration in refractory congestive heart failure

Acute right ventricular failure: pathophysiology, aetiology, assessment, and management

Acute right ventricular failure is a complex and rapidly progressive clinical syndrome, whereby the right ventricle fails to provide adequate left ventricular preload, dilates, and causes systemic venous congestion. Previous research in acute heart failure has primarily focused on the left ventricle. Yet, the need for a better understanding of right ventricular anatomy, physiology, and pathophysiology, as well as of the diagnosis and management of its acute failure is crucial. Diagnosis mandates a high degree of clinical suspicion, as the majority of signs and symptoms are nonspecific. An accurate and prompt identification of the underlying causes, including pulmonary embolism, right ventricular myocardial infarction, acute respiratory distress syndrome, post-cardiac surgery, and decompensated chronic pulmonary hypertension, is therefore essential. This review provides insights into right ventricular anatomy and functioning and discusses the pathophysiology of acute right ventricular failure, its differential aetiologies, clinical presentation, diagnosis, and treatment.

Development of a new miniaturized system for ultrafiltration

Acute decompensated heart failure and fluid overload are the most common causes of hospitalization in heart failure patients, and often, they contribute to disease progression. Initial treatment encompasses intravenous diuretics although there might be a percentual of patients refractory to this pharmacological approach. New technologies have been developed to perform extracorporeal ultrafiltration in fluid overloaded patients. Current equipment allows to perform ultrafiltration in most hospital and acute care settings. Extracorporeal ultrafiltration is then prescribed and conducted by specialized teams, and fluid removal is planned to restore a status of hydration close to normal. Recent clinical trials and European and North American practice guidelines suggest that ultrafiltration is indicated for patients with refractory congestion not responding to medical therapy. Close interaction between nephrologists and cardiologists may be the key to a collaborative therapeutic effort in heart failure patients. Further studies are today suggesting that wearable technologies might become available soon to treat patients in ambulatory and de-hospitalized settings. These new technologies may help to cope with the increasing demand for the care of chronic heart failure patients. Herein, we provide a state-of-the-art review on extracorporeal ultrafiltration and describe the steps in the development of a new miniaturized system for ultrafiltration, called AD1 (Artificial Diuresis).

Novel Medical Treatments and Devices for the Management of Heart Failure with Reduced Ejection Fraction

Heart failure (HF) is a growing issue in developed countries; it is often the result of underlying processes such as ischemia, hypertension, infiltrative diseases or even genetic abnormalities. The great majority of the affected patients present a reduced ejection fraction (≤40%), thereby falling under the name of "heart failure with reduced ejection fraction" (HFrEF). This condition represents a major threat for patients: it significantly affects life quality and carries an enormous burden on the whole healthcare system due to its high management costs. In the last decade, new medical treatments and devices have been developed in order to reduce HF hospitalizations and improve prognosis while reducing the overall mortality rate. Pharmacological therapy has significantly changed our perspective of this disease thanks to its ability of restoring ventricular function and reducing symptom severity, even in some dramatic contexts with an extensively diseased myocardium. Notably, medical therapy can sometimes be ineffective, and a tailored integration with device technologies is of pivotal importance. Not by chance, in recent years, cardiac implantable devices witnessed a significant improvement, thereby providing an irreplaceable resource for the management of HF. Some devices have the ability of assessing (CardioMEMS) or treating (ultrafiltration) fluid retention, while others recognize and treat life-threatening arrhythmias, even for a limited time frame (wearable cardioverter defibrillator). The present review article gives a comprehensive overview of the most recent and important findings that need to be considered in patients affected by HFrEF. Both novel medical treatments and devices are presented and discussed.

Contemporary Decongestive Strategies in Acute Heart Failure

Congestion is the primary driver of hospital admissions in patients with heart failure and the key determinant of their outcome. Although intravenous loop diuretics remain the predominant agents used in the setting of acute heart failure, the therapeutic response is known to be variable, with a significant subset of patients discharged from the hospital with residual hypervolemia. In this context, urinary sodium excretion has gained attention both as a marker of response to loop diuretics and as a marker of prognosis that may be a useful clinical tool to guide therapy. Several decongestive strategies have been explored to improve diuretic responsiveness and removal of excess fluid. Sequential nephron blockade through combination diuretic therapy is one of the most used methods to enhance natriuresis and counter diuretic resistance. In this article, I provide an overview of the contemporary decongestive approaches and discuss the clinical data on the use of add-on diuretic therapy. I also discuss mechanical removal of excess fluid through extracorporeal ultrafiltration with a brief review of the results of landmark studies. Finally, I provide a short overview of the strategies that are currently under investigation and may prove helpful in this setting.

Diuretics or ultrafiltration in the treatment of acute decompensated heart failure: An updated systematic review and meta-analysis

INTRODUCTION

Hospitalization for decompensated heart failure is a major public health issue.

METHODS

We performed a meta-analysis to summarize and analyze if there is a benefit in using ultrafiltration over diuretics in terms of reducing mortality or hospital readmissions, primarily and identified 10 randomized controlled trials (RCTs) including 941 patients.

RESULTS

Compared to diuretics, treatment with ultrafiltration was associated with a significant reduction in heart failure hospitalizations (risk ratio [RR]: 0.72; 95% confidence interval [CI]: 0.55-0.96, p = 0.02) and significant increase in weight and net fluid loss (mean difference [MD]: -1.55, CI: -2.36 to -0.74, p = 0.0002) and (MD: -2.10, CI: -3.32 to -0.89, p = 0.0007), respectively. There was no significant difference among treatments regarding the duration of hospitalization, the increase in serum creatinine levels, and mortality.

CONCLUSION

Among patients with decompensated heart failure, compared to diuretics, ultrafiltration is associated with reduced rehospitalizations and increased weight/net fluid loss.

Emerging Individualized Approaches in the Management of Acute Cardiorenal Syndrome With Renal Assist Devices

Growing insights into the pathophysiology of acute cardiorenal syndrome (CRS) in acute decompensated heart failure have indicated that not every rise in creatinine is associated with adverse outcomes. Detection of persistent volume overload and diuretic resistance associated with creatinine rise may identify patients with true acute CRS. More in-depth phenotyping is needed to identify pathologic processes in renal arterial perfusion, venous outflow, and microcirculatory-interstitial-lymphatic axis alterations that can contribute to acute CRS. Recently, various novel device-based interventions designed to target different pathophysiologic components of acute CRS are in early feasibility and proof-of-concept studies. However, appropriate trial endpoints that reflect improvement in cardiorenal trajectories remain elusive and highly debated. In this review the authors describe the variety of physiological derangements leading to acute CRS and the opportunity to individualize the management of acute CRS with novel renal assist devices that can target specific components of these alterations.

Cardiovascular Consequences of Acute Kidney Injury: Treatment Options

Soon after haemodialysis was introduced into clinical practice, a high risk of cardiac death was noted in end-stage renal disease. However, only in the last decade has it become clear that any renal injury, acute or chronic, is associated with high overall and cardiovascular lethality. The need for early recognition of kidney damage in cardiovascular pathology to assess risk and develop tactics for patient management contributed to the emergence of the concept of the "cardiorenal syndrome" (CRS). CRS is a pathophysiological disorder of the heart and kidneys in which acute or chronic dysfunction of one of these organs leads to acute or chronic dysfunction of the other. The beneficial effect of ultrafiltration as a component of renal replacement therapy (RRT) is due to the elimination of hyperhydration, which ultimately affects the improvement in cardiac contractile function. This review considers the theoretical background, current status of CRS, and future potential of RRT, focusing on the benefits of ultrafiltration as a therapeutic option.

Cardiac dysfunction in severe pediatric acute respiratory distress syndrome: the right ventricle in search of the right therapy

Severe acute respiratory distress syndrome in children, or PARDS, carries a high risk of morbidity and mortality that is not fully explained by PARDS severity alone. Right ventricular (RV) dysfunction can be an insidious and often under-recognized complication of severe PARDS that may contribute to its untoward outcomes. Indeed, recent evidence suggest significantly worse outcomes in children who develop RV failure in their course of PARDS. However, in this narrative review, we highlight the dearth of evidence regarding the incidence of and risk factors for PARDS-associated RV dysfunction. While we wish to draw attention to the absence of available evidence that would inform recommendations around surveillance and treatment of RV dysfunction during severe PARDS, we leverage available evidence to glean insights into potentially helpful surveillance strategies and therapeutic approaches.

Tricuspid Regurgitation Management for Heart Failure

There is growing evidence that severe tricuspid regurgitation (TR) impacts clinical outcomes in a variety of cardiovascular disease states. The late presentation of patients with advanced TR highlights the underappreciation of the disease, as well as the pitfalls of current guideline-directed medical management. Given the high in-hospital mortality associated with isolated tricuspid valve surgery, transcatheter options continue to be explored with the hope of improved survival and reduced heart failure hospitalizations. In this review, we explore the physiology of TR, discuss the etiologic classes of TR, and explore the transcatheter options for treatment and who might benefit from device therapy.

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

Background

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

Methods

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

Results

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

Conclusions

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

Pressure Overload and Right Ventricular Failure: From Pathophysiology to Treatment

Right ventricular failure (RVF) is often caused by increased afterload and disrupted coupling between the right ventricle (RV) and the pulmonary arteries (PAs). After a phase of adaptive hypertrophy, pressure-overloaded RVs evolve towards maladaptive hypertrophy and finally ventricular dilatation, with reduced stroke volume and systemic congestion. In this article, we review the concept of RV-PA coupling, which depicts the interaction between RV contractility and afterload, as well as the invasive and non-invasive techniques for its assessment. The current principles of RVF management based on pathophysiology and underlying etiology are subsequently discussed. Treatment strategies remain a challenge and range from fluid management and afterload reduction in moderate RVF to vasopressor therapy, inotropic support and, occasionally, mechanical circulatory support in severe RVF.

Safety and efficacy of perioperative continuous renal replacement therapy for percutaneous coronary intervention in severe acute myocardial infarction patients

This retrospective study aimed to evaluate the safety and efficacy of continuous renal replacement therapy (CRRT) during percutaneous coronary intervention (PCI) in patients with severe acute myocardial infarction (AMI). The study analyzed data from 945 AMI patients hospitalized between January 2016 and December 2017, out of which 21 patients underwent perioperative CRRT for PCI. We assessed the baseline characteristics of severe AMI patients before and after CRRT and examined the effect of CRRT on cardiac, renal, and liver function, as well as other indicators. The heart rate of patients undergoing CRRT was significantly lower at 24 h and 48 h after CRRT than before CRRT (p=0.038). There was a moderate but not significant decrease in the mean systolic blood pressure or diastolic blood pressure (p>0.05). Importantly, we found that significantly more patients showed Killip class I-II and significantly improved cardiac function after CRRT (23.8% vs. 57.1%, p=0.001). The levels of urea nitrogen, creatinine, aspartate aminotransferase, glutamic pyruvic transaminase, and total bilirubin were significantly lowered after CRRT treatment (p<0.05). Perioperative management of CRRT was safe and effective for severe AMI patients.

Artificial Diuresis: Animal Studies on Efficacy and Safety of a New Miniaturized Device for Extracorporeal Ultrafiltration

INTRODUCTION

We have recently developed a new miniaturized device for extracorporeal ultrafiltration (UF) to be used in patients with fluid overload: Artificial Diuresis-1 (AD1) (Medica S.p.A., Medolla, Italy). The device has a reduced priming volume, operates at very low pressures and flow regimes, and is designed to perform extracorporeal UF at bedside. After accurate experiments were carried out in vitro, we report in this paper the results of in vivo UF sessions carried out in selected animals according to veterinary best practice.

MATERIALS AND METHODS

The AD1 kit is pre-filled with sterile isotonic solution and operates with a polysulfone mini-filter, MediSulfone (polysulfone at 50,000 Dalton). A collection bag with a volumetric scale is connected to the UF line, and the ultrafiltrate is obtained by gravity based on the height at which the ultrafiltrate collection bag is placed. Animals were prepared and anesthetized. The jugular vein was cannulated with a double-lumen catheter. Three 6-h sessions of UF were scheduled with a target fluid removal of 1,500 mL. Heparin was used as anticoagulant.

RESULTS

In all treatments, the target value of UF was obtained in the absence of major clinical or technical problems with a maximum deviation from the scheduled UF rate lower than 10%. The device resulted to be safe, reliable, accurate, and easily usable thanks to a user-friendly interface and its very small dimensions.

CONCLUSIONS

This study opens the way for clinical trials in different settings including departments with low intensity of care and even in ambulatory centers or patient's home.

New Insight in Cardiorenal Syndrome: From Biomarkers to Therapy

Cardiorenal syndrome consists in the coexistence of acute or chronic dysfunction of heart and kidneys resulting in a cascade of feedback mechanisms and causing damage to both organs associated with high morbidity and mortality. In the last few years, different biomarkers have been investigated with the aim to achieve an early and accurate diagnosis of cardiorenal syndrome, to provide a prognostic role and to guide the development of targeted pharmacological and non-pharmacological therapies. In such a context, sodium-glucose cotransporter 2 (SGLT2) inhibitors, recommended as the first-line choice in the management of heart failure, might represent a promising strategy in the management of cardiorenal syndrome due to their efficacy in reducing both cardiac and renal outcomes. In this review, we will discuss the current knowledge on the pathophysiology of cardiorenal syndrome in adults, as well as the utility of biomarkers in cardiac and kidney dysfunction and potential insights into novel therapeutics.

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.

Right heart failure after left ventricular assist device: From mechanisms to treatments

Left ventricular assist device (LVAD) therapy is a lifesaving option for patients with medical therapy-refractory advanced heart failure. Depending on the definition, 5-44% of people supported with an LVAD develop right heart failure (RHF), which is associated with worse outcomes. The mechanisms related to RHF include patient, surgical, and hemodynamic factors. Despite significant progress in understanding the roles of these factors and improvements in surgical techniques and LVAD technology, this complication is still a substantial cause of morbidity and mortality among LVAD patients. Additionally, specific medical therapies for this complication still are lacking, leaving cardiac transplantation or supportive management as the only options for LVAD patients who develop RHF. While significant effort has been made to create algorithms aimed at stratifying risk for RHF in patients undergoing LVAD implantation, the predictive value of these algorithms has been limited, especially when attempts at external validation have been undertaken. Perhaps one of the reasons for poor performance in external validation is related to differing definitions of RHF in external cohorts. Additionally, most research in this field has focused on RHF occurring in the early phase (i.e., ≤1 month) post LVAD implantation. However, there is emerging recognition of late-onset RHF (i.e., > 1 month post-surgery) as a significant cause of morbidity and mortality. Late-onset RHF, which likely has a unique physiology and pathogenic mechanisms, remains poorly characterized. In this review of the literature, we will describe the unique right ventricular physiology and changes elicited by LVADs that might cause both early- and late-onset RHF. Finally, we will analyze the currently available treatments for RHF, including mechanical circulatory support options and medical therapies.

Right heart failure: A narrative review for emergency clinicians

INTRODUCTION

Right heart failure (RHF) is a clinical syndrome with impaired right ventricular cardiac output due to a variety of etiologies including ischemia, elevated pulmonary arterial pressure, or volume overload. Emergency department (ED) patients with an acute RHF exacerbation can be diagnostically and therapeutically challenging to manage.

OBJECTIVE

This narrative review describes the pathophysiology of right ventricular dysfunction and pulmonary hypertension, the methods to diagnose RHF in the ED, and management strategies.

DISCUSSION

Right ventricular contraction normally occurs against a low pressure, highly compliant pulmonary vascular system. This physiology makes the right ventricle susceptible to acute changes in afterload, which can lead to RHF. Patients with acute RHF may present with an acute illness and have underlying chronic pulmonary hypertension due to left ventricular failure, pulmonary arterial hypertension, chronic lung conditions, thromboemboli, or idiopathic conditions. Patients can present with a variety of symptoms resulting from systemic edema and hemodynamic compromise. Evaluation with electrocardiogram, laboratory analysis, and imaging is necessary to evaluate cardiac function and end organ injury. Management focuses on treating the underlying condition, optimizing oxygenation and ventilation, treating arrhythmias, and understanding the patient's hemodynamics with bedside ultrasound. As RHF patients are preload dependent they may require fluid resuscitation or diuresis. Hypotension should be rapidly addressed with vasopressors. Cardiac contractility can be augmented with inotropes. Efforts should be made to support oxygenation while trying to avoid intubation if possible.

CONCLUSIONS

Emergency clinician understanding of this condition is important to diagnose and treat this life-threatening cardiopulmonary disorder.

Ultrafiltration for acute heart failure

BACKGROUND

Pharmacotherapies such as loop diuretics are the cornerstone treatment for acute heart failure (AHF), but resistance and poor response can occur. Ultrafiltration (UF) is an alternative therapy to reduce congestion, however its benefits, efficacy and safety are unclear.

OBJECTIVES

To assess the effects of UF compared to diuretic therapy on clinical outcomes such as mortality and rehospitalisation rates.

SEARCH METHODS

We undertook a systematic search in June 2021 of the following databases: CENTRAL, MEDLINE, Embase, Web of Science CPCI-S and ClinicalTrials.gov. We also searched the WHO ICTRP platform in October 2020.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared UF to diuretics in adults with AHF.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. We contacted study authors for any further information, and language interpreters to translate texts. We assessed risk of bias in included studies using Risk of Bias 2 (RoB2) tool and assessed the certainty of the evidence using GRADE.

MAIN RESULTS

We included 14 trials involving 1190 people. We included people who had clinical signs of acute hypervolaemia. We excluded critically unwell people such as those with ischaemia or haemodynamic instability. Mean age ranged from 57.5 to 75 years, and the setting was a mix of single and multi-centre. Two trials researched UF as a complimentary therapy to diuretics, while the remaining trials withheld diuretic use during UF. There was high risk of bias in some studies, particularly with deviations from the intended protocols from high cross-overs as well as missing outcome data for long-term follow-up.  We are uncertain about the effect of UF on all-cause mortality at 30 days or less (risk ratio (RR) 0.61, 95% confidence interval (CI) 0.13 to 2.85; 3 studies, 286 participants; very low-certainty evidence). UF may have little to no effect on all-cause mortality at the longest available follow-up (RR 1.00, 95% CI 0.73 to 1.36; 9 studies, 987 participants; low-certainty evidence). UF may reduce all-cause rehospitalisation at 30 days or less (RR 0.76, 95% CI 0.53 to 1.09; 3 studies, 337 participants; low-certainty evidence). UF may slightly reduce all-cause rehospitalisation at longest available follow-up (RR 0.91, 95% CI 0.79 to 1.05; 6 studies, 612 participants; low-certainty evidence). UF may reduce heart failure-related rehospitalisation at 30 days or less (RR 0.62, 95% CI 0.37 to 1.04; 2 studies, 395 participants; low-certainty evidence). UF probably reduces heart failure-related rehospitalisation at longest available follow-up, with a number needed to treat for an additional beneficial effect (NNTB) of 10 (RR 0.69, 95% CI 0.53 to 0.90; 4 studies, 636 participants; moderate-certainty evidence).  No studies measured need for mechanical ventilation.  UF may have little or no effect on serum creatinine change at 30 days since discharge (mean difference (MD) 14%, 95% CI -12% to 40%; 1 study, 221 participants; low-certainty evidence). UF may increase the risk of new initiation of renal replacement therapy at longest available follow-up (RR 1.42, 95% CI 0.42 to 4.75; 4 studies, 332 participants; low-certainty evidence).  There is an uncertain effect of UF on the risk of complications from central line insertion in hospital (RR 4.16, 95% CI 1.30 to 13.30; 6 studies, 779 participants; very low-certainty evidence).  AUTHORS' CONCLUSIONS: This review summarises the latest evidence on UF in AHF. Moderate-certainty evidence shows UF probably reduces heart failure-related rehospitalisation in the long term, with an NNTB of 10. UF may reduce all-cause rehospitalisation at 30 days or less and at longest available follow-up. The effect of UF on all-cause mortality at 30 days or less is unclear, and it may have little effect on all-cause mortality in the long-term.  While UF may have little or no effect on serum creatinine change at 30 days, it may increase the risk of new initiation of renal replacement therapy in the long term. The effect on complications from central line insertion is unclear.  There is insufficient evidence to determine the true impact of UF on AHF. Future research should evaluate UF as an adjunct therapy, focusing on outcomes such as heart failure-related rehospitalisation, cardiac mortality and renal outcomes at medium- to long-term follow-up.

Inferior Vena Cava Collapsibility Index: Clinical Validation and Application for Assessment of Relative Intravascular Volume

Accurate assessment of relative intravascular volume is critical to guide volume management of patients with acute or chronic kidney disorders, particularly those with complex comorbidities requiring hospitalization or intensive care. Inferior vena cava (IVC) diameter variability with respiration measured by ultrasound provides a dynamic noninvasive point-of-care estimate of relative intravascular volume. We present details of image acquisition, interpretation, and clinical scenarios to which IVC ultrasound can be applied. The variation in IVC diameter over the respiratory or ventilatory cycle is greater in patients who are volume responsive than those who are not volume responsive. When 2 recent prospective studies of spontaneously breathing patients (n = 214) are added to a prior meta-analysis of 181 patients, for a total of 7 studies of 395 spontaneously breathing patients, IVC collapsibility index (CI) had a pooled sensitivity of 71% and specificity of 81% for predicting volume responsiveness, which is similar to a pooled sensitivity of 75% and specificity of 82% for 9 studies of 284 mechanically ventilated patients. IVC maximum diameter <2.1 cm, that collapses >50% with or without a sniff is inconsistent with intravascular volume overload and suggests normal right atrial pressure (0-5 mmHg). Inferior vena cava collapsibility (IVC CI) < 20% with no sniff suggests increased right atrial pressure and is inconsistent with overt hypovolemia in spontaneously breathing or ventilated patients. These IVC CI cutoffs do not appear to vary greatly depending on whether patients are breathing spontaneously or are mechanically ventilated. Patients with lower IVC CI are more likely to tolerate ultrafiltration with hemodialysis or improve cardiac output with ultrafiltration. Our goal for IVC CI generally ranges from 20% to 50%, respecting potential biases to interpretation and overriding clinical considerations. IVC ultrasound may be limited by factors that affect IVC diameter or collapsibility, clinical interpretation, or optimal visualization, and must be interpreted in the context of the entire clinical situation.

Renal dysfunction in cardiovascular diseases and its consequences

It is well known that the heart and kidney and their synergy is essential for hemodynamic homeostasis. Since the early XIX century it has been recognized that cardiovascular and renal diseases frequently coexist. In the nephrological field, while it is well accepted that renal diseases favor the occurrence of cardiovascular diseases, it is not always realized that cardiovascular diseases induce or aggravate renal dysfunctions, in this way further deteriorating cardiac function and creating a vicious circle. In the same clinical field, the role of venous congestion in the pathogenesis of renal dysfunction is at times overlooked. This review carefully quantifies the prevalence of chronic and acute kidney abnormalities in cardiovascular diseases, mainly heart failure, regardless of ejection fraction, and the consequences of renal abnormalities on both organs, making cardiovascular diseases a major risk factor for kidney diseases. In addition, with regard to pathophysiological aspects, we attempt to substantiate the major role of fluid overload and venous congestion, including renal venous hypertension, in the pathogenesis of acute and chronic renal dysfunction occurring in heart failure. Furthermore, we describe therapeutic principles to counteract the major pathophysiological abnormalities in heart failure complicated by renal dysfunction. Finally, we underline that the mild transient worsening of renal function after decongestive therapy is not usually associated with adverse prognosis. Accordingly, the coexistence of cardiovascular and renal diseases inevitably means mediating between preserving renal function and improving cardiac activity to reach a better outcome.

Effects of modified ultrafiltration and conventional ultrafiltration combination on perioperative clinical outcomes in pediatric cardiac surgery: A meta-analysis

BACKGROUND

This meta-analysis was performed to review the effects of the addition of modified ultrafiltration (MUF) and conventional ultrafiltration (CUF) to CUF alone on postoperative hemoglobin, surgical and ultrafiltration data, and postoperative clinical outcomes in pediatric patients undergoing cardiac surgery.

METHODS

A systematic search was performed to identify randomized controlled clinical trials that compared MUF and CUF combination with CUF alone in pediatric cardiac surgery undergoing cardiopulmonary bypass (CPB) in PubMed, Embase, Cochrane Library, and Web of Science without any language or date limitation in February 2020. For each included trial, the primary outcomes including post-CPB and postoperative hematocrit, surgical and ultrafiltration data, postoperative clinical outcomes including volume of chest tube drainage within 48 hours after surgery and perioperative blood requirement, ventilation support duration, and length of stay day in the intensive care unit (ICU) and hospital were collected and analyzed. The analysis was conducted using STATA version 12.0.

RESULTS

A total of 8 trials encompassing 405 patients were included in this analysis. Analysis indicated that MUF + CUF increased the post-CPB hematocrit (Standard mean difference, SMD = 1.85, 95% confidence interval, 95% CI 0.91-2.79). Meanwhile, ultrafiltration volume was higher in CUF+MUF infants than CUF-alone infants (SMD = 1.46, 95% CI 0.51-2.41, P = .003). The clinical outcomes, including postoperative hemodynamic changes, prime volume, blood requirement, chest tube drainage volume, mechanical ventilation duration, and ICU duration, were unclear because of the unstable sensitivity analyses.

CONCLUSIONS

Beneficial effects of using MUF and CUF for pediatric cardiac surgery, including increase post-CPB hematocrit and ultrafiltration volume when compared with CUF alone. Meanwhile, MUF and CUF did not significantly influence the postoperative hospital stay duration, CPB, and aortic occlusion duration.

Estimated plasma volume status in heart failure: clinical implications and future directions

Congestion is one of the main predictors of poor outcome in patients with heart failure (HF). Assessing and monitoring congestion is essential for optimizing HF therapy. Among the various available methods, serial measurements of estimated plasma volume (ePVS) using routine blood count and/or body weight (e.g., the Strauss, Duarte, Hakim formulas) may be useful in HF management. Further prospective study is warranted to determine whether ePVS can help optimize decongestion therapy (loop diuretics, mineralocorticoid receptor antagonists, SGLT2i) in various HF settings. This narrative review summarizes the recent evidence supporting the association of ePVS with clinical congestion and outcome(s) and discusses future directions for monitoring ePVS in HF.

Changes in cardiac output with hemodialysis relate to net volume balance and to inferior vena cava ultrasound collapsibility in critically ill patients

Cardiac output may increase after volume administration with relative intravascular volume depletion, or after ultrafiltration (UF) with relative intravascular volume overload. Assessing relative intravascular volume using respiratory/ventilatory changes in inferior vena cava (IVC) diameters may guide volume management to optimize cardiac output in critically ill patients requiring hemodialysis (HD) and/or UF.We retrospectively studied 22 critically ill patients having relative intravascular volume assessed by IVC Collapsibility Index (IVC CI) = (IVCmax-IVCmin)/IVCmax*100%, within 24 h of cardiac output measurement, during 37 intermittent and 21 continuous HD encounters. Cardiac output increase >10% was considered significant. Net volume changes between cardiac outputs were estimated from "isonatremic volume equivalent" (0.9% saline) gains and losses.Cardiac output increased >10% in 15 of 42 encounters with IVC CI <20% after net volume removal, and in 1 of 16 encounters with IVC CI ≥20% after net volume administration (p = 0.0136). All intermittent and continuous HD encounters resulted in intradialytic hypotension. Net volume changes between cardiac output measurements were significantly less (median +1.0 mL/kg) with intractable hypotension or vasopressor initiation, and net volume removal was larger (median -22.9 mL/kg) with less severe intradialytic hypotension (p < 0.001). Cardiac output increased >10% more frequently with least severe intradialytic hypotension and decreased with most severe intradialytic hypotension (p = 0.047).In summary, cardiac output may increase with net volume removal by ultrafiltration in some critically ill patients with relative intravascular volume overload assessed by IVC collapsibility. Severe intradialytic hypotension may limit volume removal with ultrafiltration, rather than larger volume removal causing severe intradialytic hypotension.

Prophylactic hemodialysis following coronary angiography and one-year outcomes in non-dialysis patients with chronic kidney disease: A propensity-matched study

BACKGROUND/PURPOSE

Prophylactic hemodialysis after coronary angiography in patients with chronic kidney disease (CKD) prevents contrast nephropathy; however, the one-year outcomes are unclear. This study aimed to investigate the one-year outcomes of prophylactic hemodialysis against standard treatment in patients with CKD who underwent coronary angiography.

METHODS

A cohort study of 359 patients with CKD, coronary artery disease (CAD), and serum creatinine levels of 176.8-530.4 μmol/L, who were referred for elective coronary angiography was conducted. Propensity score matching identified 118 patient pairs for outcome comparisons. The hemodialysis group underwent prophylactic hemodialysis after coronary angiography, whereas the control group received standard treatment. The study's primary outcome was free from dialysis was considered the primary outcome, whereas the secondary outcome was overall survival. Unadjusted estimates of the probability of free from dialysis and overall survival were computed using Kaplan-Meier survival curves and log-rank tests. Cox proportional-hazards regression models were used in determining the risk factors associated with ESRD and mortality.

RESULTS

During a mean 9.3 months follow-up duration, the hemodialysis group had significantly better free from dialysis (85.6% vs. 64.4%; P = 0.002) and overall survival (85.4% vs. 78.5%; P = 0.008) rates than the control group. Cox proportional-hazards regression analyses of the propensity score-matched patients showed that the hemodialysis group had reduced risks for ESRD and mortality (hazard ratios, 0.32 and 0.48, respectively).

CONCLUSION

Prophylactic Hemodialysis following coronary angiography was associated with reduced ESRD and mortality risks in CKD patients with CAD, who did not routinely undergo dialysis.

Cardiorenal Syndrome: Classification, Pathophysiology, Diagnosis, and Treatment Strategies: A Scientific Statement From the American Heart Association

Cardiorenal syndrome encompasses a spectrum of disorders involving both the heart and kidneys in which acute or chronic dysfunction in 1 organ may induce acute or chronic dysfunction in the other organ. It represents the confluence of heart-kidney interactions across several interfaces. These include the hemodynamic cross-talk between the failing heart and the response of the kidneys and vice versa, as well as alterations in neurohormonal markers and inflammatory molecular signatures characteristic of its clinical phenotypes. The mission of this scientific statement is to describe the epidemiology and pathogenesis of cardiorenal syndrome in the context of the continuously evolving nature of its clinicopathological description over the past decade. It also describes diagnostic and therapeutic strategies applicable to cardiorenal syndrome, summarizes cardiac-kidney interactions in special populations such as patients with diabetes mellitus and kidney transplant recipients, and emphasizes the role of palliative care in patients with cardiorenal syndrome. Finally, it outlines the need for a cardiorenal education track that will guide future cardiorenal trials and integrate the clinical and research needs of this important field in the future.

Estimated plasma volume and mortality: analysis from NHANES 1999-2014

BACKGROUND

While estimated plasma volume (ePV) has been studied in some diseases, such as heart failure, the relationship between ePV and all-cause or cause-specific mortality remains unexplored. Therefore, we investigated the association between ePV and all-cause, cardiovascular (CV), and cancer-related mortality among adults in the US.

METHOD

We used the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2014 and included participants older than 18 years. Mortality data were obtained from the National Death Index and matched to the NHANES participants. ePV was derived using Strauss formula. Cox proportional hazard models were fit to estimate hazard ratios for all-cause and cause-specific mortality without and with adjustment for potential confounders.

RESULTS

Of the 42,705 participants, 5194 died (1121 CV deaths) during mean follow-up of 8.0 (range 0-16.7) years. Mean ± SD age and ePV of the participants were 47.2 ± 19.4 years and 4.2 ± 0.84, respectively. In unadjusted models, 1 unit increase in ePV was associated with 29%, 32%, and 16% increased risk in all-cause (HR 1.29; 95% CI 1.24, 1.35), CV (HR 1.32; 95% CI 1.22, 1.43), and cancer-related (HR 1.16; 95% CI 1.05, 1.27) mortality. Risk remained high in adjusted models (all-cause HR 1.24; 95% CI 1.18, 1.30; CV HR 1.22; 95% CI 1.11, 1.34; cancer-specific HR 1.24; 95% CI 1.10, 1.39). When comparing the highest and lowest ePV quartiles, similar results were noted (adjusted all-cause HR 1.64; 95% CI 1.45, 1.86; CV HR 1.52; 95% CI 1.19, 1.93; cancer HR 1.85; 95% CI 1.38, 2.49).

CONCLUSION

An increase in ePV was associated with increased all-cause and cause-specific mortality. Further studies are needed to explore the mechanism of this relationship and translation into a better outcome.

Long-term Prognostic Value of Estimated Plasma Volume in Heart Failure with Preserved Ejection Fraction

Plasma volume, estimated by several indirect methods, has been viewed as a biological surrogate for intravascular fluid status. The clinical implication of estimated plasma volume status (ePVS) for long term outcomes in heart failure with preserved ejection fraction (HFpEF) remains unclear. We investigate the prognostic value of ePVS calculated by Strauss formula and its association with cardiovascular events and mortality in a prospective HFpEF cohort. There were 449 individuals met the inclusion criteria of our cohort. Estimated plasma volume variation (ΔePVS) and its instantaneous derivatives were calculated by the Strauss formula. Our study endpoints were events of heart failure hospitalization and mortality. Kaplan–Meier estimates and Cox regression analysis were applied to determine the power of ΔePVS and baseline ePVS in predicting long term cardiovascular outcomes. Both baseline ePVS and ΔePVS were independent predictors of heart failure hospitalization and mortality. Kaplan-Meier estimates of these outcomes stratified by optimal cut-off value showed that HFpEF individuals with higher baseline ePVS and ΔePVS were associated with elevated risk of composite endpoint of heart failure hospitalization and mortality. This study demonstrated the prognostic value of a novel biological surrogate, instantaneous derivatives ePVS, in predicting long term cardiovascular outcomes in HFpEF population. Monitoring instantaneous plasma volume may assist in identifying patients at high risk for future cardiovascular events. Further prospective studies validating the role of ePVS in predicting long-term prognosis in patients with HFpEF are warranted.

Limited agreement between two noninvasive measurements of blood volume during fluid removal: ultrasound of inferior vena cava and finger-clip spectrophotometry of hemoglobin concentration

OBJECTIVE

Plots of blood volume measurements over time (profiles) may identify euvolemia during fluid removal for acute heart failure. We assessed agreement between two noninvasive measurements of blood volume profiles during mechanical fluid removal, which exemplifies the interstitial fluid shifts that occur during diuretic-induced fluid removal.

APPROACH

During hemodialysis we compared change in maximum diameter of the inferior vena cava by ultrasound ([Formula: see text]) to change in relative blood volume derived from capillary hemoglobin concentration from finger-clip spectrophotometry (RBV_SpHb). We grouped profiles of these measurements into three distinct shapes using an unbiased, data-driven modeling technique.

METHODS

Fifty patients who were not in acute heart failure underwent a mean of five paired measurements while an average of 1.3 liters of fluid was removed over 2 h during single hemodialysis sessions. [Formula: see text] changed  -1.0 mm (95% CI  -1.9 to  -0.2 mm) and the RBV_SpHb changed  -1.1% (95% CI  -2.7 to  +0.5%), but these changes were not correlated (r  -0.04, 95% CI  -0.32 to  +0.24). Nor was there agreement between categorization of profiles of change in the two measurements (kappa  -0.1, 95% CI  -0.3 to  +0.1).

SIGNIFICANCE

[Formula: see text] and RBV_SpHb estimates of blood volume do not agree during mechanical fluid removal, likely because regional changes in blood flow and pressure modify IVC dimensions as well as changes total blood volume.

Ultrafiltration in Acute Heart Failure

Congestion is the predominant cause of more than 1 million annual heart failure hospitalisations and recurrent fluid overload predicts poor outcomes. Unresolved congestion trumps serum creatinine increases in predicting adverse heart failure outcomes. No pharmacological approach for acute heart failure has reduced these deleterious consequences. Simplified ultrafiltration devices permit fluid removal in lower acuity hospital settings, but results regarding safety and efficacy have been variable. However, adjustment of ultrafiltration rates to patients’ vital signs and renal function has been associated with more effective decongestion and fewer heart failure events. Many aspects of ultrafiltration, including patient selection, fluid removal rates, venous access, prevention of therapy-related complications and costs, require further investigation.

Edema of Advanced Cancer: Prevalence, Etiology, and Conservative Management-A Single Hospice Cross-Sectional Study

CONTEXT

Edema of advanced cancer, seldom recognized in the literature, significantly impairs patient quality of life.

OBJECTIVES

The purpose was to assess edema frequency, etiology, and impact on common symptoms and present its conservative management.

METHODS

A prospective analysis of 784 patients admitted to a hospice was performed, of whom 119 were diagnosed with edema. For 18 patients with short life prognosis, an individually tailored physiotherapy (limb elevation, bandaging, manual lymphatic drainage, and Kinesio Taping) or subcutaneous needle drainage was administered. Forty-six patients with longer prognosis were treated by standardized limb bandaging (5-7 days) and re-evaluated, 28 of them with venous congestion resistant to enteral diuretics received supplementary furosemide infusion.

RESULTS

Among those admitted with edema (96.6% with advanced cancer), 81.5% had bilateral and 10.9% generalized edema, 10.9% had lymphorrhea, 5.9% skin ulcerations, and in 27.7% edema was the main problem. The high mean comorbidity C3-index score (2.97) was observed. The main precipitating factors of the edema were chronic immobilization (79.8%) medications (58.8%), and congestive heart failure (28.6%). Before admission, 47.9% had received diuretics for edema and only 4.2% had physiotherapy. Among those re-evaluated (46 patients [84 limbs]), the mean reduction of limb volume (1.18L; 16.6%; P < 0.001) was accompanied by a decrease of edema symptoms/signs intensity and ESAS-Core by median 1 point (P < 0.002).

CONCLUSION

Limb edema of advanced cancer occasionally treated by physical therapy concerns patients with numerous comorbidities and precipitating factors. It can be managed sufficiently with decongestive or supportive physiotherapy, depending on patients' life prognosis, symptom burden, edema stage, and progression.

Ultrafiltration for the Treatment of Acute Heart Failure

Ultrafiltration (UF) mechanically removes excess fluid volume through an extracorporeal circuit and has been applied to clinical situations in which volume removal is the mainstay of therapy. Because of this ability, UF serves as an enticing method to treat acute heart failure (AHF) in which most symptoms are driven by congestion due to excess volume. Additional physiologic properties of UF and the biochemical composition of the extracted fluid confer additional theoretic benefits in the treatment of AHF. Herein the concepts underlying UF, clinical evidence evaluating its efficacy, and ongoing challenges understanding the role of UF are reviewed.

Renal replacement therapy in patients with acute respiratory distress syndrome: a single-center retrospective study

Background

Patients with acute respiratory distress syndrome (ARDS) who develop acute kidney injury have increased mortality and frequently require renal replacement therapy (RRT). The optimal timing for initiation of RRT after onset of ARDS to improve survival is not known.

Methods

We retrospectively reviewed clinical data on patients admitted to our health system over a 2-year period. Individual charts were carefully reviewed to ascertain that patients met the Berlin criteria for ARDS and to categorize RRT utilization. The Kaplan–Meier analysis was conducted to compare early (£48 hours postintubation) versus late (>48 hours postintubation) initiation of RRT. Associations between RRT initiation and mortality were evaluated using Cox proportional hazards regression.

Results

A total of 75 patients were identified with ARDS, 95% of whom received RRT. Mortality of patients who required RRT was 56%. The main indications for RRT initiation were fluid overload (75%), metabolic acidosis (64%), and hyperkalemia (33%). The Kaplan–Meier analysis comparing early initiation of RRT to late initiation of RRT showed no survival benefit. Cox proportional hazard models testing the association between timing of RRT initiation with survival and adjusting for sex, race, ethnicity, and Acute Physiology and Chronic Health Evaluation II score did not reach statistical significance (HR=0.94, 95% CI=0.48–1.86).

Conclusion

Timing of RRT initiation was not associated with a survival benefit. Prospective study in the utilization and outcomes of RRT in ARDS could assist in optimizing its usage in this population.

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.

Evaluation and Management of Right-Sided Heart Failure: A Scientific Statement From the American Heart Association

Background and Purpose:

The diverse causes of right-sided heart failure (RHF) include, among others, primary cardiomyopathies with right ventricular (RV) involvement, RV ischemia and infarction, volume loading caused by cardiac lesions associated with congenital heart disease and valvular pathologies, and pressure loading resulting from pulmonic stenosis or pulmonary hypertension from a variety of causes, including left-sided heart disease. Progressive RV dysfunction in these disease states is associated with increased morbidity and mortality. The purpose of this scientific statement is to provide guidance on the assessment and management of RHF.

Methods:

The writing group used systematic literature reviews, published translational and clinical studies, clinical practice guidelines, and expert opinion/statements to summarize existing evidence and to identify areas of inadequacy requiring future research. The panel reviewed the most relevant adult medical literature excluding routine laboratory tests using MEDLINE, EMBASE, and Web of Science through September 2017. The document is organized and classified according to the American Heart Association to provide specific suggestions, considerations, or reference to contemporary clinical practice recommendations.

Results:

Chronic RHF is associated with decreased exercise tolerance, poor functional capacity, decreased cardiac output and progressive end-organ damage (caused by a combination of end-organ venous congestion and underperfusion), and cachexia resulting from poor absorption of nutrients, as well as a systemic proinflammatory state. It is the principal cause of death in patients with pulmonary arterial hypertension. Similarly, acute RHF is associated with hemodynamic instability and is the primary cause of death in patients presenting with massive pulmonary embolism, RV myocardial infarction, and postcardiotomy shock associated with cardiac surgery. Functional assessment of the right side of the heart can be hindered by its complex geometry. Multiple hemodynamic and biochemical markers are associated with worsening RHF and can serve to guide clinical assessment and therapeutic decision making. Pharmacological and mechanical interventions targeting isolated acute and chronic RHF have not been well investigated. Specific therapies promoting stabilization and recovery of RV function are lacking.

Conclusions:

RHF is a complex syndrome including diverse causes, pathways, and pathological processes. In this scientific statement, we review the causes and epidemiology of RV dysfunction and the pathophysiology of acute and chronic RHF and provide guidance for the management of the associated conditions leading to and caused by RHF.

Negative Fluid Balance in Sepsis: When and How?

Fluid resuscitation plays a fundamental role in the treatment of septic shock. Administration of inappropriately large quantities of fluid may lead to volume overload, which is increasingly recognized as an independent risk factor for morbidity and mortality in critical illness. In the early treatment of sepsis, timely fluid challenges should be given to optimize organ perfusion, but continuous positive fluid balance is discouraged. In fact, achievement of a negative fluid balance during treatment of sepsis is associated with better outcomes. This review will discuss the relationship between fluid overload and unfavorable outcomes in sepsis, and how fluid overload can be prevented and managed.

Hemofiltration in Heart Failure

In patients with severe congestive heart failure (CHF), removal of edema by hemofiltration is associated with significant clinical and hemodynamic improvement, correction of hyponatremia, restoration of urine output and diuretic responsiveness, and with a striking fall in neurohormonal activation. Through these effects, hemofiltration is able to interrupt the progression of CHF toward refractoriness, and to revert the clinical condition of CHF patients to a lower functional class.

Fluid refilling from the overhydrated interstitium is the major compensatory mechanism in the prevention of hypovolemia during hemofiltration.

Hemofiltration can also be beneficial in patients who have only moderate cardiac insufficiency (NYHA classes II and III) and in whom over-hydration is restricted to the pulmonary district significantly contributing to limiting patients functional capacity. In this setting, hemofiltration, differently from diuretics, is able to remove the increased lung water content and to improve clinical condition, exercise capacity and lung function.

Extracorporeal Ultrafiltration for Acute Exacerbations of Chronic Heart Failure: Report from the Acute Dialysis Quality Initiative

This report from a work group affiliated with the Acute Dialysis Quality Initiative is a critical assessment of the use of extracorporeal ultrafiltration (UF) in the management of acutely decompensated heart failure (HF). In addition to assessing UF in this setting, the report also provides background information on HF, including classification, pathophysiology, and the importance of concomitant renal failure. A summary of important results from clinical trials in this area is provided, along with a discussion of technical considerations. Finally, specific recommendations for future clinical evaluations are given.

Extracorporeal ultrafiltration for acute heart failure: patient selection and perspectives

Most patients presenting with acute heart failure (AHF) show signs and symptoms of fluid overload, which are closely associated with short-term and long-term outcomes. Ultrafiltration is an extremely appealing strategy for patients with AHF and concomitant overt fluid overload not fully responsive to diuretic therapy. However, although there are several theoretical beneficial effects associated with ultrafiltration, published reports have shown controversial findings. Differences in selection of the study population and in ultrafiltration indications and protocols, and high variability in the pharmacologic therapy used for the control group could explain some of these conflicting results. Here, we aimed to provide an overview on the current medical evidence supporting the use of ultrafiltration in AHF, with a special focus on the identification of potential candidates who may benefit the most from this therapeutic option.

Extracorporeal Ultrafiltration for Fluid Overload in Heart Failure: Current Status and Prospects for Further Research

More than 1 million heart failure hospitalizations occur annually, and congestion is the predominant cause. Rehospitalizations for recurrent congestion portend poor outcomes independently of age and renal function. Persistent congestion trumps serum creatinine increases in predicting adverse heart failure outcomes. No decongestive pharmacological therapy has reduced these harmful consequences. Simplified ultrafiltration devices permit fluid removal in lower-acuity hospital settings, but with conflicting results regarding safety and efficacy. Ultrafiltration performed at fixed rates after onset of therapy-induced increased serum creatinine was not superior to standard care and resulted in more complications. In contrast, compared with diuretic agents, some data suggest that adjustment of ultrafiltration rates to patients’ vital signs and renal function may be associated with more effective decongestion and fewer heart failure events. Essential aspects of ultrafiltration remain poorly defined. Further research is urgently needed, given the burden of congestion and data suggesting sustained benefits of early and adjustable ultrafiltration.

Ultrafiltration versus intravenous loop diuretics in patients with acute decompensated heart failure: a meta-analysis of clinical trials

Background Intravenous loop diuretics are the first-line therapy for acute decompensated heart failure (ADHF) but many patients are discharged with unresolved congestion resulting in higher re-hospitalization and mortality rates. Ultrafiltration (UF) is a promising intervention for ADHF. However, studies comparing UF to diuretics have been inconsistent in their clinical outcomes. Methods A comprehensive literature search was performed. Trials were included if they met the following criteria: (1) randomization with a control group, (2) comparison of UF with a loop diuretic, and (3) a diagnosis of ADHF. Results When compared to diuretics, UF was associated with a reduced risk of clinical worsening (odds ratio (OR) 0.57, 95% CI: 0.38-0.86, P-value 0.007), increased likelihood for clinical decongestion (OR 2.32, 95% CI: 1.09-4.91, P-value 0.03) with greater weight (0.97 Kg, 95% CI: 0.52-1.42, P-value <0.0001) and volume reduction (1.11 L, 95% CI: 0.68-1.54, P-value <0.0001). The overall risk of re-hospitalization (OR 0.92, 95% CI: 0.62-1.38, P-value 0.70), return to emergency department (OR 0.69, 95% CI: 0.44-1.08, P-value 0.10) and mortality (OR 0.99, 95% CI: 0.60-1.62, P-value 0.97) were not significantly improved by UF treatment. Conclusions UF is associated with significant improvements in clinical decongestion but not in rates of re-hospitalization or mortality.

Focused Real-Time Ultrasonography for Nephrologists

We propose that renal consults are enhanced by incorporating a nephrology-focused ultrasound protocol including ultrasound evaluation of cardiac contractility, the presence or absence of pericardial effusion, inferior vena cava size and collapsibility to guide volume management, bladder volume to assess for obstruction or retention, and kidney size and structure to potentially gauge chronicity of renal disease or identify other structural abnormalities. The benefits of immediate and ongoing assessment of cardiac function and intravascular volume status (prerenal), possible urinary obstruction or retention (postrenal), and potential etiologies of acute kidney injury or chronic kidney disease far outweigh the limitations of bedside ultrasonography performed by nephrologists. The alternative is reliance on formal ultrasonography, which creates a disconnect between those who order, perform, and interpret studies, creates delays between when clinical questions are asked and answered, and may increase expense. Ultrasound-enhanced physical examination provides immediate information about our patients, which frequently alters our assessments and management plans.

The effect of combined conventional and modified ultrafiltration on mechanical ventilation and hemodynamic changes in congenital heart surgery

Background:

Cardiopulmonary bypass is associated with increased fluid accumulation around the heart which influences pulmonary and cardiac diastolic function. The aim of this study was to compare the effects of modified ultrafiltration (MUF) versus conventional ultrafiltration (CUF) on duration of mechanical ventilation and hemodynamic status in children undergoing congenital heart surgery.

Materials and Methods:

A randomized clinical trial was conducted on 46 pediatric patients undergoing cardiopulmonary bypass throughout their congenital heart surgery. Arteriovenous MUF plus CUF was performed in 23 patients (intervention group) and sole CUF was performed for other 23 patients (control group). In MUF group, arterial cannula was linked to the filter inlet through the arterial line, and for 10 min, 10 ml/kg/min of blood was filtered and returned via cardioplegia line to the right atrium. Different parameters including hemodynamic variables, length of mechanical ventilation, Intensive Care Unit (ICU) stay, and inotrope requirement were compared between the two groups.

Results:

At immediate post-MUF phase, there was a statistically significant increase in the mean arterial pressure, systolic blood pressure, and diastolic blood pressure (P < 0.05) only in the study group. Furthermore, there was a significant difference in time of mechanical ventilation (P = 0.004) and ICU stay (P = 0.007) between the two groups. Inotropes including milrinone (P = 0.04), epinephrine (P = 0.001), and dobutamine (P = 0.002) were used significantly less frequently for patients in the intervention than the control group.

Conclusion:

Administration of MUF following surgery improves hemodynamic status of patients and also significantly decreases the duration of mechanical ventilation and inotrope requirement within 48 h after surgery.

Role of isolated ultrafiltration in the management of chronic refractory and acute decompensated heart failure

Chronic congestive heart failure (CHF) and acute decompensated heart failure (ADHF) refractory to medical therapy represent therapeutic challenges. In such patients, attempts to reduce pulmonary and systemic congestion frequently produce deterioration of renal function. In studies of patients with chronic severe CHF refractory to medical therapy (including loop diuretics), isolated ultrafiltration was frequently able to relieve congestive symptoms by precise removal of extracellular water and sodium, and in some cases was able to restore responsiveness to loop diuretics. Randomized controlled trials comparing isolated ultrafiltration and medical therapy (mainly loop diuretics) in patients with ADHF failed to demonstrate the superiority of isolated ultrafiltration over diuretic therapy with respect to renal function and mortality. Isolated ultrafiltration reduced length of hospital stay in several studies. At this time, there is insufficient evidence to support the use of isolated ultrafiltration as initial therapy of ADHF.

Acute Decompensated Heart Failure

Heart failure (HF) is a societal burden due to its high prevalence, frequent admissions for acute decompensated heart failure (ADHF), and the economic impact of direct and indirect costs associated with HF and ADHF. Common etiologies of ADHF include medication and diet noncompliance, arrhythmias, deterioration in renal function, poorly controlled hypertension, myocardial infarction, and infections. Appropriate medical management of ADHF in patients is guided by the identification of signs and symptoms of fluid overload or low cardiac output and utilization of evidence-based practices. In patients with fluid overload, various strategies for diuresis or ultrafiltration may be considered. Depending on hemodynamics and patient characteristics, vasodilator, inotropic, or vasopressor therapies may be of benefit. Upon ADHF resolution, patients should be medically optimized, have lifestyle modifications discussed and implemented, and medication concierge service considered. After discharge, a multidisciplinary HF team should follow up with the patient to ensure a safe transition of care. This review article evaluates the management options and considerations when treating a patient with ADHF.

[Congestive heart failure: Treatment with ultrafiltration]

INTRODUCTION

The prevalence rate of congestive heart failure is approximately 2% in high-income countries. The aim of this study was to assess the overall benefit of ultrafiltration therapy in patients with acute or persistent congestive heart failure.

METHODS

We conducted a health technology assessment following the EUnetHTA guidelines, with systematic literature review from bibliographic medical databases, independent experts and manufacturer interviews.

RESULTS

Thirteen clinical trials and five meta-analyses were examined. In the most recent one, 608 patients were included, of which 304 received ultrafiltration therapy and 304 received intravenous loop diuretics. Ultrafiltration therapy seems to be more beneficial regarding the fluid removal and the body weight reduction, (mean difference respectively 1.44kg, IC95% [0.29; 2.59], P-value=0.01 and 1.28L [0.43; 2.12], P-value=0.003). No difference has been showed in overall mortality, renal function, hospital readmission or safety. Medico-economic studies are incomplete and contradictory.

CONCLUSION

Ultrafiltration therapy seems to be effective, most likely for patients ineligible or resistant to intravenous diuretics. But most topics remain uncertain, mainly impact on overall mortality, safety and cost-effectiveness. Given these knowledge-gaps, the generalization of ultrafiltration therapy should be examined cautiously, and conditional upon a large-scale systematic evaluation.

Ultrafiltration Therapy for Heart Failure: Balancing Likely Benefits against Possible Risks

Heart failure remains a major public health concern because of its high prevalence, morbidity, mortality, and financial burden. The poor clinical outcomes associated with acute decompensated heart failure, suboptimal efficacy and safety profile of conventional treatment regimens, and unsatisfactory experiences with the newer classes of pharmacologic therapy underlie the interest in the use of extracorporeal isolated ultrafiltration in this setting. In this article, selected mechanistic aspects of ultrafiltration therapy are briefly reviewed followed by a critical overview of the largest trials in this field. I will discuss the clinical relevance of renal dysfunction and decongestion as two commonly used end points of safety and efficacy in the ultrafiltration trials, with emphasis on the emerging pertinent notions that could challenge our conventional thinking. Finally, a number of practical recommendations (e.g., customization of ultrafiltration rates) are provided for ultrafiltration therapy in the setting of acute decompensated heart failure. Because of a paucity of evidence, universally accepted consensus guidelines cannot yet be generated. As such, when considering ultrafiltration therapy for acute decompensated heart failure, the likely benefits should be carefully balanced against the potential risks for an individual patient. A conceivable implication of the ultrafiltration trials is that collaborative heart failure programs benefiting from nephrology expertise and resources could improve the outcomes and reduce the cost.