Ultrafiltration for heart failure: how fast should we move?

Extracorporeal shock wave treatment attenuated left ventricular dysfunction and remodeling in mini-pig with cardiorenal syndrome

This study tested the hypothesis that extracorporeal shock wave (ECSW) treatment can improve ischemia-induced left ventricular (LV) dysfunction in mini-pig with co-existing chronic kidney disease (CKD). LV ischemia in mini-pigs was induced by applying an ameroid constrictor over mid-left anterior descending artery (LAD), while model of CKD was established by right nephrectomy with partial ligation of left renal arterioles 2 weeks before LAD constriction. Thirty mini-pigs were randomly divided into group 1 (sham-control), group 2 (LV-ischemia), group 3 (LV-ischemia + CKD), Group 4 [LV-ischemia + ECSW (applied 1200 shots at 0.1 mJ/m²/equally to 4-ischemic regions by day-90 after LAD constriction], and group 5 (LV-ischemia-CKD + ECSW). By day-180 after CKD induction, echocardiography showed that LV ejection fraction (LVEF) was highest in group 1, lowest in group 3, significantly lower in group 2 than that in groups 4 and 5, and significantly lower in group 5 than that in group 4, whereas LV-end systolic and diastolic dimensions displayed an opposite pattern (all p<0.001). Protein expressions of oxidative-stress (NOX-1/NOX-2/oxidized protein), apoptotic (cleaved-caspase-3/cleaved-PARP/mitochondrial-Bax), fibrotic (TGF-β/Smad3), pressure/volume-overload (BNP/β-MHC), endothelial (CD31/vWF) and mitochondrial-integrity (PGC-1/mitochondrial-cytochrome-C) biomarkers exhibited a pattern identical to that of LVEF, whereas angiogenesis factors (VEGF/CXCR4/SDF-1α) showed significant progressive increase among all groups (all p<0.0001). Microscopic findings of CD31+cells/vWF+cells/small-vessel density/sarcomere-length showed an identical pattern, whereas collagen-deposition area/fibrotic area/apoptotic nuclei expressed an opposite pattern compared to that of LVEF among all groups (all p<0.0001). In conclusion, CKD aggravated ischemia-induced LV dysfunction and remodeling and molecular-cellular perturbations that were reversed by ECSW treatment.

The cardioprotective effect of melatonin and exendin-4 treatment in a rat model of cardiorenal syndrome

We investigated the cardioprotective effect of melatonin (Mel) and exendin-4 (Ex4) treatment in a rat model of cardiorenal syndrome (CRS). Adult male SD rats (n=48) were randomly and equally divided into sham control (SC), dilated cardiomyopathy (DCM) (doxorubicin 7 mg/kg i.p. every five days/4 doses), CRS (defined as DCM+CKD) only, CRS-Mel (20 mg/kg/d), CRS-Ex4 (10 μg/kg/d), and CRS-Mel-Ex4 groups. In vitro results showed protein expressions of oxidative stress (NOX-1/NOX-2/oxidized protein), DNA/mitochondrial damage (γ-H2AX/cytosolic cytochrome c), apoptosis (cleaved caspase-3/PARP), and senescence (β-galactosidase cells) biomarkers were upregulated, whereas mitochondrial ATP level was decreased in doxorubicin/p-cresol-treated H9c2 cells that were revised by Mel and Ex4 treatments (all P<.001). By day 60, LVEF was highest in the SC and lowest in the CRS, significantly lower in the DCM than in other treatment groups, lower in the CRS-Mel and CRS-Ex4 than in the CRS-Mel-Ex4, and lower in the CRS-Mel than in the CRS-Ex4, whereas LV chamber size and histopathology score showed a pattern opposite to that of LVEF among all groups (all P<.001). Plasma creatinine level was highest in the CRS and lowest in the SC and progressively decreased from the CRS-Mel, CRS-Ex4, CRS-Mel-Ex4 to DCM (P<.0001). Protein expressions of inflammation (TNF-α/NF-κB/MMP-2/MMP-9/IL-1β), apoptosis/DNA damage (Bax/c-caspase-3/c-PARP/γ-H2AX), fibrosis (Smad3/TGF-β), oxidative stress (NOX-1/NOX-2/NOX-4/oxidized protein), cardiac hypertrophy/pressure overload (BNP/β-MHC), and cardiac integrity (Cx43/α-MHC) biomarkers in LV myocardium showed an opposite pattern compared to that of LVEF among all groups (all P<.001). Fibrotic area, DNA damage (γ-H2AX⁺ /53BP1⁺ CD90⁺ /XRCC1⁺ CD90⁺ ), and inflammation (CD14⁺ /CD68⁺ ) biomarkers in LV myocardium displayed a pattern opposite to that of LVEF among all groups (all P<.001). Combined melatonin and exendin-4 treatment suppressed CRS-induced deterioration of LVEF and LV remodeling.

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.

Cardiorenal syndrome: ultrafiltration therapy for heart failure--trials and tribulations

Heart failure remains the leading cause of hospitalization in older patients and is considered a growing public health problem with a significant financial burden on the health care system. The suboptimal efficacy and safety profile of diuretic-based therapeutic regimens coupled with unsatisfactory results of the studies on novel pharmacologic agents have positioned ultrafiltration on the forefront as an appealing therapeutic option for patients with acute decompensated heart failure (ADHF). In recent years, substantial interest in the use of ultrafiltration has been generated due to the advent of dedicated portable devices and promising results of trials focusing both on mechanistic and clinical aspects of this therapeutic modality. This article briefly reviews the proposed benefits of ultrafiltration therapy in the setting of ADHF and summarizes the major findings of the currently available studies in this field. The results of more recent trials on cardiorenal syndrome that present a counterpoint to previous observations and highlight certain limitations of ultrafiltration therapy are then discussed, followed by identification of major challenges and unanswered questions that could potentially hinder its more widespread use. Future studies are warranted to shed light on less well characterized aspects of ultrafiltration therapy and to further define its role in ADHF and cardiorenal syndrome.

Extracorporeal versus peritoneal ultrafiltration in diuretic-resistant congestive heart failure--a review

Diuretic-resistant congestive heart failure in the form of type 2 cardiorenal syndrome is a problem of growing significance in everyday clinical practice because of high morbidity and mortality. There has been scant progress in the treatment of overhydration, the main cause of symptoms in this group of patients. The aim of our review is to present recent advances in the ultrafiltration therapy of congestive heart failure, with special attention to the new dedicated device for extracorporeal isolated ultrafiltration, as well as modifications of peritoneal dialysis in the form of peritoneal ultrafiltration with icodextrin solution and incremental peritoneal dialysis. Technical and clinical features, costs and potential risks of available devices for isolated ultrafiltration are presented. This method should be reserved for patients with true diuretic resistance as part of a more complex strategy aiming at the adequate control of fluid retention. Peritoneal ultrafiltration is presented as a viable alternative to extracorporeal ultrafiltration because of medical and psychosocial benefits of home-based therapy, lower costs and more effective daily ultrafiltration. In conclusion, large, properly randomized and controlled clinical trials with long-term follow-up will be essential in assessing the logistics and cost-effectiveness of both methods. Most importantly, however, they should be able to evaluate the impact of both methods on preservation of renal function and delaying the progression of heart failure by interrupting the vicious circle of cardiorenal syndrome. Our review is supplemented with the case report of the use of peritoneal ultrafiltration with a single 12-hour nighttime icodextrin exchange as a life-saving procedure in a patient with congestive heart failure resistant to pharmacological treatment.<br />

Decongestive treatment of acute decompensated heart failure: cardiorenal implications of ultrafiltration and diuretics

In patients with acute decompensated heart failure (ADHF), treatment aimed at adequate decongestion of the volume overloaded state is essential. Despite diuretic therapy, many patients remain volume overloaded and symptomatic. In addition, adverse effects related to diuretic treatment are common, including worsening kidney function and electrolyte disturbances. The development of decreased kidney function during treatment affects the response to diuretic therapy and is associated with important clinical outcomes, including mortality. The occurrence of diuretic resistance and the morbidity and mortality associated with diuretic therapy has stimulated interest to develop effective and safe treatment strategies that maximize decongestion and minimize decreased kidney function. During the last few decades, extracorporeal ultrafiltration has been used to remove fluid from diuretic-refractory hypervolemic patients. Recent clinical studies using user-friendly machines have suggested that ultrafiltration may be highly effective for decongesting patients with ADHF. Many questions remain regarding the comparative impact of diuretics and ultrafiltration on important clinical outcomes and adverse effects, including decreased kidney function. This article serves as a summary of key clinical studies addressing these points. The overall goal is to assist practicing clinicians who are contemplating the use of ultrafiltration for a patient with ADHF.

Ultrafiltration in heart failure

Fluid overload is a key pathophysiologic mechanism underlying both the acute decompensation episodes of heart failure and the progression of the syndrome. Moreover, it represents the most important factor responsible for the high readmission rates observed in these patients and is often associated with renal function worsening, which by itself increases mortality risk. In this clinical context, ultrafiltration (UF) has been proposed as an alternative to diuretics to obtain a quicker relief of pulmonary/systemic congestion. This review illustrates technical issues, mechanisms, efficacy, safety, costs, and indications of UF in heart failure. The available evidence does not support the widespread use of UF as a substitute for diuretic therapy. Owing to its operative characteristics, UF cannot be expected to directly influence serum electrolyte levels, azotemia, and acid-base balance, or to remove high-molecular-weight substances (eg, cytokines) in clinically relevant amounts. Ultrafiltration should be used neither as a quicker way to achieve a sort of mechanical diuresis nor as a remedy for an inadequately prescribed and administered diuretic therapy. Instead, it should be reserved to selected patients with advanced heart failure and true diuretic resistance, as part of a more complex strategy aiming at an adequate control of fluid retention.

Ultrafiltration in the management of acute decompensated heart failure

PURPOSE OF REVIEW

Admissions to hospital for acute decompensated heart failure continue to increase and represent a significant burden on both patients' and healthcare resources. The majority of these admissions are for the control of volume overload; however, standard treatment with intravenous diuretics is not always effective and can lead to increased renal morbidity. One alternative to standard therapy is mechanical fluid removal with ultrafiltration, this review will highlight the current evidence and efficacy regarding ultrafiltration use in acute heart failure.

RECENT FINDINGS

Multiple recent clinical trials have demonstrated the safety and feasibility of ultrafiltration in the management of acute heart failure. Ultrafiltration may be more effective at removing fluid than standard diuretic therapy and has been associated with beneficial long-term results. However, it remains to be determined whether ultrafiltration is truly nephroprotective and when and how this therapy is best utilized.

SUMMARY

Ultrafiltration is an attractive alternative to standard diuretic therapy in the management of volume overload from acute heart failure. Further research is needed to confirm the cost-effectiveness and to determine long-term impacts on morbidity and mortality.

The role of ultrafiltration in patients with decompensated heart failure

Congestion, due in large part to hypervolemia, is the primary driver of heart failure (HF) admissions. Relief of congestion has been traditionally achieved through the use of loop diuretics, but there is increasing concern that these agents, particularly at high doses, may be deleterious in the inpatient setting. In addition, patients with HF and the cardiorenal syndrome (CRS) have diminished response to loop diuretics, making these agents less effective at relieving congestion. Ultrafiltration, a mechanical volume removal strategy, has demonstrated promise in achieving safe and effective volume removal in patients with cardiorenal syndrome and diuretic refractoriness. This paper outlines the rationale for ultrafiltration in CRS and the available evidence regarding its use in patients with HF. At present, the utility of ultrafiltration is restricted to selected populations, but a greater understanding of how this technology impacts HF and CRS may expand its use.

Utility of daily diuretic orders for identifying acute decompensated heart failure patients for quality improvement

INTRODUCTION

Many studies have demonstrated gaps in adherence to American College of Cardiology (ACC)/American Heart Association (AHA) guidelines among patients with acute decompensated heart failure (ADHF). Quality improvement initiatives can improve compliance with guideline-recommended therapy yet a major challenge to such programs is identifying heart failure patients across the many wards and services of the complex hospital environment.

METHODS AND RESULTS

Using our hospital's electronic order-entry system, we generated a daily list of all hospitalized patients receiving a loop diuretic. Over a 3-month period, each patient on this list was screened through chart review for a diagnosis of ADHF. For those patients with ADHF, a clinical reminder about ACC/AHA recommended therapies was placed in the chart. Patient outcomes were followed using the Get With The Guidelines heart failure database.During the study period, 98.6% of patients with ADHF were identified by the diuretics list. The diuretics list had a sensitivity of 98.6% and specificity of 92.2%. The diuretic list captured more ADHF patients than alternative methods such as chest x-ray and brain natriuretic peptide level. Use of the daily diuretic list and targeted reminders to clinicians was associated with an improvement in recommended therapies including smoking-cessation education and heart failure teaching.

CONCLUSIONS

A daily list of inpatients receiving diuretics allowed real-time identification of most hospitalized heart failure patients at our institution. Targeted reminders to clinicians regarding ACC/AHA-recommended therapies for heart failure were associated with improvements in guideline adherence.

Need for a unified decision-making tool for ultrafiltration therapy in heart failure; call for action

Although ultrafiltration portends several theoretical advantages over the standard therapy for acute decompensated heart failure, it might not be the optimal treatment for all patients presenting with an episode of decompensation. It is not yet clear how to prospectively identify the subset of patients that would benefit from this therapeutic modality. Based on the pathophysiologic mechanisms underlying acute decompensated heart failure, early ultrafiltration therapy can be an appropriate initial management strategy for those patients with diuretic resistance whose associated renal dysfunction is related to hemodynamic changes rather than a structural abnormality. In the absence of widely accepted consensus guidelines, ultrafiltration use is currently subject to considerable variations among physicians. A clinical tool (eg, a scoring system) that is based on the individual patient's characteristics is therefore needed to prospectively identify the appropriate candidates for this therapy. Using this system is likely to portend better outcomes while helping to avoid unnecessary exposure to potential risks of extracorporeal therapies.

Ultrafiltration does not affect certain predictors of outcome in heart failure

Ultrafiltration as a therapeutic option for heart failure has been of more recent interest due to a proposed physiologic basis for its mechanism of action and the development of newer technology. Several studies have so far demonstrated its efficacy in rapid removal of fluid and improvement in congestive symptoms. However, there is currently no data on its impact on long-term outcomes of patients with heart failure. Moreover, evidence extracted from available studies does not support any beneficial impact on established predictors of mortality in this setting (i.e. blood urea nitrogen and serum sodium levels). This observation coupled with previous data indicating lack of expected beneficial effect on renal function highlights the emergent need for robust long-term outcome studies prior to expansion of the implementation of this complicated and costly therapy.