Clinical benefit and approach of ultrafiltration in acute heart failure

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.

Extracorporeal Isolated Ultrafiltration for Management of Congestion in Heart Failure and Cardiorenal Syndrome

Acute decompensated heart failure has the highest rate of hospital readmission among all medical conditions and portends a significant financial burden on health care system. Congestion, the hallmark of acute decompensated heart failure, represents the primary reason for hospitalization and the driver of adverse outcomes in these patients. Although diuretic-based medical regimens remain the mainstay of management of acute decompensated heart failure, they often show suboptimal efficacy and safety profiles in this setting. Mechanical extraction of excess fluid through extracorporeal ultrafiltration therapy has been proposed as a mechanistically relevant option in this setting. The advent of simplified, portable, and user-friendly devices that are dedicated to ultrafiltration therapy for these patients has renewed the interest in this therapeutic modality. In this article, we provide a brief overview of the initial mechanistic studies followed by the key clinical findings of the most recent landmark trials. The shortcomings of these studies are discussed in detail because not only do they provide the appropriate context in which the results are to be interpreted, but more importantly they also highlight the existing knowledge gaps that need to be addressed in future studies. Finally, selected practical and conceptual considerations and controversies are reviewed with regard to evidence-based ultrafiltration therapy.

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.

Venous congestion, endothelial and neurohormonal activation in acute decompensated heart failure: cause or effect?

Venous congestion and endothelial and neurohormonal activation are known to occur in acute decompensated heart failure (ADHF), yet the temporal role of these processes in the pathophysiology of decompensation is not fully understood. Conventional wisdom presumes congestion to be a consequence of worsening cardiovascular function; however, the biomechanically driven effects of venous congestion are biologically plausible contributors to ADHF that remain largely unexplored in vivo. Recent experimental evidence from human models suggests that fluid accumulation and venous congestion are not simply consequences of poor cardiovascular function, but rather are fundamental pro-oxidant, pro-inflammatory, and hemodynamic stimuli that contribute to acute decompensation. The latest advances in the monitoring of volume status using implantable devices allow for the detection of venous congestion before symptoms arise. This may ultimately lead to improved treatment strategies including not only diuretics, but also specific, adjuvant interventions to counteract endothelial and neurohormonal activation during early preclinical decompensation.

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.

Efficacy and cardiovascular tolerability of continuous veno-venous hemodiafiltration in acute decompensated heart failure: a randomized comparative study

BACKGROUND AND OBJECTIVES

Recently, continuous veno-venous hemodiafiltration (CVVHDF) has received increased attention in the treatment of congestive heart failure (CHF). The aim of this study is to assess the safety and efficacy of CVVHDF compared with intravenous furosemide in patients with CHF.

METHODS

Forty patients having CHF were included in this prospective, randomized, comparative trial. We randomized patients to treatment for 72 hours with CVVHDF or intravenous furosemide. Outcomes assessed were weight loss, total fluid output, length of stay (LOS) in the intensive care unit (ICU), 30-day mortality, and cardiovascular stability.

RESULTS

Demographic data were comparable in both groups. Weight loss (P ≤ .05) and total fluid output (P ≤ .01) were greater in the CVVHDF group. Length of stay in the ICU was significantly reduced in the CVVHDF group (P ≤ .05). The mortality rates were comparable in both groups. The cardiac output and the stroke volume significantly increased, whereas the pulmonary capillary wedge pressure significantly decreased (P ≤ .05) in both groups compared with the baseline. A transient attack of hypotension occurred in 1 patient in the CVVHDF group.

CONCLUSION

In CHF, the use of CVVHDF effectively and safely produced greater weight and fluid loss and decreased LOS in the ICU more than the intravenous furosemide with no hemodynamic instability.

Effects of ULTRAfiltration vs. DIureticS on clinical, biohumoral and haemodynamic variables in patients with deCOmpensated heart failure: the ULTRADISCO study

AIMS

To evaluate the clinical, biohumoral, and haemodynamic effects of ultrafiltration vs. intravenous diuretics in patients with decompensated heart failure (HF). Signs and symptoms of volume overload are often present in these patients and standard therapy consists primarily of intravenous diuretics. Increasing evidence suggests that ultrafiltration can be an effective alternative treatment.

METHODS AND RESULTS

Thirty patients with decompensated HF were randomly assigned to diuretics or ultrafiltration. Haemodynamic variables, including several novel parameters indicating the overall performance of the cardiovascular system, were continuously assessed with the Pressure Recording Analytical Method before, during, at the end of treatment (EoT) and 36 h after completing treatment. Aldosterone and N-terminal pro-B-type natriuretic peptide (NT-proBNP) plasma levels were also measured. Patients treated with ultrafiltration had a more pronounced reduction in signs and symptoms of HF at EoT compared with baseline, and a significant decrease in plasma aldosterone (0.24 ± 0.25 vs. 0.86 ± 1.04 nmol/L; P < 0.001) and NT-proBNP levels (2823 ± 2474 vs. 5063 ± 3811 ng/L; P < 0.001) compared with the diuretic group. The ultrafiltration group showed a significant improvement (% of baseline) in a number of haemodynamic parameters, including stroke volume index (114.0 ± 11.7%; P < 0.001), cardiac index (123.0 ± 20.8%; P < 0.001), cardiac power output (114.0 ± 13.8%; P < 0.001), dP/dt(max) (129.5 ± 19.9%; P < 0.001), and cardiac cycle efficiency (0.24 ± 0.54 vs. -0.14 ± 0.50 units; P < 0.05), and a significant reduction in systemic vascular resistance 36 h after the treatment (88.0 ± 10.9%; P < 0.001), which was not observed in the diuretic group.

CONCLUSIONS

In patients with advanced HF, ultrafiltration facilitates a greater clinical improvement compared with diuretic infusion by ameliorating haemodynamics (assessed using a minimally invasive methodology) without a marked increase in aldosterone or NT-proBNP levels.

Ultrafiltration for congestive heart failure

Relief of congestive symptoms is a primary goal in treating heart failure. Ultrafiltration is a tool that can be used to safely remove sodium and water from whole blood at a controlled rate. Ultrafiltration decreases symptoms, relieves congestion, and improves hemodynamics, neurohormonal balance, and exercise capacity. This article describes the importance of congestion as a therapeutic target in heart failure and outlines the development of ultrafiltration as a treatment to address this important physiologic state.

Pharmacologic approaches for volume excess in acute kidney injury (AKI)

Volume management is an integral component of the care of patients with acute kidney injury (AKI). Considerable controversy exists regarding the use of pharmacological agents for volume management. Although overt fluid overload is often seen in AKI and may prompt attention for the use of diuretics, often these agents are used in the absence of fluid retention. Over the last decade several new agents have become available for volume removal. We reviewed the literature on this topic and addressed four key questions for the appropriate utilization of these agents. These include the drug targets and mechanism of action of available agents; clinical goals and criteria for timing of intervention; adaptation of therapy for specific clinical settings and measures required for monitoring effectiveness and patient safety. This report details our current knowledge in this area, provides evidence-based clinical practice recommendations where appropriate, and formulates a research agenda to address unanswered questions.

New therapies in acute decompensated heart failure

PURPOSE OF REVIEW

Hospitalization and mortality rates associated with heart failure are persistently high. This is due partly to aging of the population but mostly to delayed progress in the pharmacological treatment of decompensated heart failure. We will review the current recommendations and most recent advancement in the pharmacological treatment of acute decompensated heart failure while providing a systematic approach to the management of this prevalent condition.

RECENT FINDINGS

Loop diuretics, nitrates and inotropes such as dobutamine and milrinone are the current mainstay of acute heart failure management although their associated morbidity and possible mortality have raised serious concerns. Recent vasoactive agents such as Nesiritide, Tolvaptan and more recently the inotropic agent Levosimedan could offer improved hemodynamics and congestive relief to patients in acute pulmonary edema.

SUMMARY

Despite the promising results of these agents, further clinical trials are required prior to their international approval as first-line therapy. Although we can be optimistic that these vasoactive drugs might have favorable clinical outcomes and improve the intricate management of decompensated heart failure, their associated mortality benefit remains unclear and controversial.

Beyond pulmonary edema: diagnostic, risk stratification, and treatment challenges of acute heart failure management in the emergency department

The majority of heart failure hospitalizations in the United States originate in the emergency department (ED). Current strategies for acute heart failure syndromes have largely been tailored after chronic heart failure guidelines and care. Prospective ED-based acute heart failure syndrome trials are lacking, and current guidelines for disposition are based on either little or no evidence. As a result, the majority of ED acute heart failure syndrome patients are admitted to the hospital. Recent registry data suggest there is a significant amount of heterogeneity in acute heart failure syndrome ED presentations, and diagnostics and therapeutics may need to be individualized to the urgency of the presentation, underlying pathophysiology, and acute hemodynamic characteristics. A paradigm shift is necessary in acute heart failure syndrome guidelines and research: prospective trials need to focus on diagnostic, therapeutic, and risk-stratification algorithms that rely on readily available ED data, focusing on outcomes more proximate to the ED visit (5 days). Intermediate outcomes (30 days) are more dependent on inpatient and outpatient care and patient behavior than ED management decisions. Without these changes, the burden of acute heart failure syndrome care is unlikely to change. This article proposes such a paradigm shift in acute heart failure syndrome care and discusses areas of further research that are necessary to promote this change in approach.

Canadian Cardiovascular Society Consensus Conference recommendations on heart failure update 2007: Prevention, management during intercurrent illness or acute decompensation, and use of biomarkers

Heart failure is common, yet it is difficult to treat. It presents in many different guises and circumstances in which therapy needs to be individualized. The Canadian Cardiovascular Society published a comprehensive set of recommendations in January 2006 on the diagnosis and management of heart failure, and the present update builds on those core recommendations. Based on feedback obtained through a national program of heart failure workshops during 2006, several topics were identified as priorities because of the challenges they pose to health care professionals. New evidence-based recommendations were developed using the structured approach for the review and assessment of evidence adopted and previously described by the Society. Specific recommendations and practical tips were written for the prevention of heart failure, the management of heart failure during intercurrent illness, the treatment of acute heart failure, and the current and future roles of biomarkers in heart failure care. Specific clinical questions that are addressed include: which patients should be identified as being at high risk of developing heart failure and which interventions should be used? What complications can occur in heart failure patients during an intercurrent illness, how should these patients be monitored and which medications may require a dose adjustment or discontinuation? What are the best therapeutic, both drug and nondrug, strategies for patients with acute heart failure? How can new biomarkers help in the treatment of heart failure, and when and how should BNP be measured in heart failure patients? The goals of the present update are to translate best evidence into practice, to apply clinical wisdom where evidence for specific strategies is weaker, and to aid physicians and other health care providers to optimally treat heart failure patients to result in a measurable impact on patient health and clinical outcomes in Canada.

Ultrafiltration versus intravenous diuretics for patients hospitalized for acute decompensated heart failure

OBJECTIVES

This study was designed to compare the safety and efficacy of veno-venous ultrafiltration and standard intravenous diuretic therapy for hypervolemic heart failure (HF) patients.

BACKGROUND

Early ultrafiltration may be an alternative to intravenous diuretics in patients with decompensated HF and volume overload.

METHODS

Patients hospitalized for HF with > or =2 signs of hypervolemia were randomized to ultrafiltration or intravenous diuretics. Primary end points were weight loss and dyspnea assessment at 48 h after randomization. Secondary end points included net fluid loss at 48 h, functional capacity, HF rehospitalizations, and unscheduled visits in 90 days. Safety end points included changes in renal function, electrolytes, and blood pressure.

RESULTS

Two hundred patients (63 +/- 15 years, 69% men, 71% ejection fraction < or =40%) were randomized to ultrafiltration or intravenous diuretics. At 48 h, weight (5.0 +/- 3.1 kg vs. 3.1 +/- 3.5 kg; p = 0.001) and net fluid loss (4.6 vs. 3.3 l; p = 0.001) were greater in the ultrafiltration group. Dyspnea scores were similar. At 90 days, the ultrafiltration group had fewer patients rehospitalized for HF (16 of 89 [18%] vs. 28 of 87 [32%]; p = 0.037), HF rehospitalizations (0.22 +/- 0.54 vs. 0.46 +/- 0.76; p = 0.022), rehospitalization days (1.4 +/- 4.2 vs. 3.8 +/- 8.5; p = 0.022) per patient, and unscheduled visits (14 of 65 [21%] vs. 29 of 66 [44%]; p = 0.009). No serum creatinine differences occurred between groups. Nine deaths occurred in the ultrafiltration group and 11 in the diuretics group.

CONCLUSIONS

In decompensated HF, ultrafiltration safely produces greater weight and fluid loss than intravenous diuretics, reduces 90-day resource utilization for HF, and is an effective alternative therapy. (The UNLOAD trial; http://clinicaltrials.gov/ct/show/NCT00124137?order=1; NCT00124137).

Management of fluid overload in congestive heart failure: learning from a case report

A case of refractory fluid overload due to congestive heart failure and consequent renal insufficiency is reported. The case was approached multidisciplinarily, at the beginning with conservative and pharmacological therapy, subsequently with extracorporeal fluid removal in which a specific attention was payed to the maintenance of circulating blood volume and achievement of dry weight, and finally with chronic peritoneal dialysis as a maintenance therapy. The case seems to summarize the pathway of many patients seen initially in intensive care and cardiology departments and subsequently in nephrological wards.

Contemporary Issues in the Pharmacologic Management of Acute Heart Failure

Acute heart failure is an evolving syndrome that continues to be defined by ongoing studies and registries. It is associated with significant morbidity and mortality and places a huge economic burden on health care systems. Improved understanding of the underlying pathophysiologic processes has prompted interest into understanding the implications of current and future pharmacologic management strategies beyond hemodynamics. Diuretics, vasodilators, and inotropes remain the mainstays of therapy with several new classes of agents on the horizon. Clinicians should understand the rationale for use and limitations of each therapy to maximize benefit and cost-effectiveness, while minimizing the potential for adverse outcomes.

Ultrafiltration in decompensated heart failure

Fluid congestion is the hallmark of decompensated heart failure. As heart failure progresses, reduced response to diuretics is common. In these patients, ultrafiltration has been found to alleviate excess volume and improve diuretic sensitivity. Compared with diuretics, ultrafiltration provides a more predictable and safer way to achieve euvolemia with minimal electrolyte abnormalities and neurohormonal activation. The emerging familiarity and ease of use of ultrafiltration suggests that in the future this will be an important therapy for the treatment of acute and chronic volume overload associated with decompensated heart failure.

Ultrafiltration Versus Usual Care for Hospitalized Patients With Heart Failure

OBJECTIVES

The purpose of this research was to assess the safety and efficacy of ultrafiltration (UF) in patients admitted with decompensated congestive heart failure (CHF).

BACKGROUND

Ultrafiltration for CHF is usually reserved for patients with renal failure or those unresponsive to pharmacologic management. We performed a randomized trial of UF versus usual medical care using a simple UF device that does not require special monitoring or central intravenous access.

METHODS

Patients admitted for CHF with evidence of volume overload were randomized to a single, 8 h UF session in addition to usual care or usual care alone. The primary end point was weight loss 24 h after the time of enrollment.

RESULTS

Forty patients were enrolled (20 UF, 20 usual care). Ultrafiltration was successful in 18 of the 20 patients in the UF group. Fluid removal after 24 h was 4,650 ml and 2,838 ml in the UF and usual care groups, respectively (p = 0.001). Weight loss after 24 h, the primary end point, was 2.5 kg and 1.86 kg in the UF and usual care groups, respectively (p = 0.240). Patients tolerated UF well.

CONCLUSIONS

The early application of UF for patients with CHF was feasible, well-tolerated, and resulted in significant weight loss and fluid removal. A larger trial is underway to determine the relative efficacy of UF versus standard care in acute decompensated heart failure.

Continuous Renal Replacement Therapy for Management of Overhydration in Heart Failure

An estimated 4.8 million Americans are diagnosed with heart failure. Of those, 5% to 10% meet criteria for the refractory state of the disease. While therapeutic interventions continue to evolve with the changing conceptualization of heart failure pathophysiology, overhydration and its deleterious sequelae remain a problem for those in the refractory state. The incidence of heart failure continues to rise in older individuals. As baby-boomers age across America, greater focus on new, more effective therapies must be considered for treatment of this disease. Continuous renal replacement therapy (CRRT) is one such treatment. The gentle removal of fluid and metabolites while maintaining electrolyte balance helps reduce the effects of overhydration in patients with heart failure. Increasing use of the therapy in the refractory state of heart failure is generating support for early initiation as it continues to demonstrate positive effects. Reduction in edema, attenuation of the sympathoadrenal cascade, and improved respiratory status have all been documented using the therapy. The intent of this article is to provide information for advanced practice nurses and direct care providers regarding CRRT for the treatment of heart failure refractory to typical therapy.

New and emerging drug therapies for the management of acute heart failure

In recent times, there have been many developments in therapies for acute heart failure, in contrast to the preceding 20 years. These have been mainly fueled by new and expanding knowledge about the pathophysiology of heart failure, which has allowed for insight into potential therapeutic strategies. This review will examine the key emerging therapies for acute heart failure, in light of available pathophysiological and clinical evidence.

Nonpharmacologic care of heart failure: counseling, dietary restriction, rehabilitation, treatment of sleep apnea, and ultrafiltration

The prognosis of patients with chronic congestive heart failure (CHF) depends not only on pharmacologic therapy but also on nonpharmacologic aspects. A complete and ongoing education program for treating CHF includes an understanding of the causes of CHF, symptoms, diet, salt and fluid restriction, drug regimen, compliance, physical and work activities, lifestyle changes, and measures of self-control. Moreover, the nonpharmacologic treatment (dietary modifications, lifestyle, physical exercise, and health care education) must be inserted in a multidisciplinary program organized by the physician in conjunction with the health system, the nurses, and, especially, the patients themselves, who must understand their disease and the many therapeutic options. Cardiologists should treat patients in a clear and comprehensible way, and other specialists (dietitians, physiotherapists, psychologists, nurses, and social workers), together with the patient's family, should strive for the best living conditions for the patient. In this way, the treatment of CHF can improve the quantity and quality of life and save a significant amount in health care costs.

Protect the heart in the intensive care unit--but how?

The heart plays a pivotal role in determining the oxygen supply to the body. As a result of its high oxygen extraction ratio, the myocardium must function efficiently to supply itself with oxygen. In the context of the ICU, the efficient functioning of the myocardium is confounded by a number of pathologic processes that may interfere with its oxygen supply or increase its oxygen demand. Conventional drug treatment of acute myocardial decompensation tends to increase myocardial oxygen demand. The myocardium may potentially be "protected" by treatment modalities that favorably alter the oxygen supply to demand ratio. Newer methods of protecting the heart may involve improving the coordination of myocardial contraction, using novel inotropic agents, supporting the myocardium metabolically, administrating blood products more conservatively, favorably altering the immune response, and using mechanical support devices. Myocardial protection may be improved by better use and understanding of monitors of myocardial performance.

Continuous renal replacement therapy: opinions and evidence

Continuous arteriovenous haemofiltration (CAVH) is the first example of continuous renal replacement therapy (CRRT). CAVH was first applied for the treatment of diuretic unresponsive fluid overload. Subsequently, CRRT has undergone a remarkable growth, and it is now performed with pump technology (CVVH) and via double-lumen central venous catheters. In many intensive care units, especially in Australia and in Europe, CRRT has become the dominant, if not exclusive, form of artificial renal support. Continuous haemofiltration is now used beyond the original indications of blood purification, for the treatment of certain drug intoxications, for severe cardiac failure, for volume control during, after cardiopulmonary bypass, and to decrease the toxicity of chemotherapy. Furthermore, there is strong ongoing research into its role or that of derived techniques as possible adjuvant therapies during severe sepsis. Despite its large use, the current state of CRRT is surrounded by some controversies, and an effort should be made to give a dispassionate distillation of the literature for a final common definition of what is based on opinions and what carries sufficient evidence.