Slow continuous ultrafiltration: a means of unmasking myocardial functional reserve in end-stage cardiac disease

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.

The challenge of treating congestion in advanced heart failure

Volume overload is a common manifestation of heart failure decompensation. Interaction between impaired renal and heart function constitutes an important pathophysiologic mechanism that leads to congestion. In addition to improving symptoms and volume status, reduction of rehospitalization rates, maintenance of renal function and improvement of survival are all important goals of every therapeutic strategy. Currently, the use of diuretics, vasodilators, inotropes and ultrafiltration, together with investigational agents such as oral vasopressin antagonists and adenosine A1-receptor antagonists, constitute the main therapeutic options for the congested heart failure patient.

Efficacy and safety of continuous hemodiafiltration for acute decompensated heart failure

The mortality of heart failure patients with renal insufficiency is high, and these patients tend to develop diuretic resistance. Under these conditions, continuous hemodiafiltration (CHDF) is a possible alternative volume reduction therapy to diuretics. However, its efficacy and safety are not clear. Between April 2005 and March 2008, 248 patients with acute decompensated heart failure were admitted to the CCU of Kyoto City Hospital. Of those patients, 31 (20 volume overloaded heart failure, 11 cardiogenic shock) received CHDF therapy, and their weight loss, acute hemodynamic changes, and clinical outcome were assessed to evaluate the efficacy and safety of CHDF therapy. CHDF was performed for 6.5 +/- 6.5 days. There was no significant change in acute hemodynamics after CHDF initiation. In the volume overloaded heart failure (VH) group, significant weight loss was observed at 24 hours and 48 hours after CHDF initiation (P < 0.001). In-hospital mortality of the VH group and cardiogenic shock (CS) group were 10.0% and 54.5%, respectively. CHDF for acute decompensated heart failure (ADHF) is a safe, effective, and reliable volume reduction therapy for volume overloaded heart failure. Further investigation is required to assess the effectiveness of CHDF for cardiogenic shock.

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.

Ultrafiltration in the management of heart failure

PURPOSE OF REVIEW

Congestion causes the majority of hospitalizations for heart failure and contributes to heart failure progression and mortality. Intravenous loop diuretics reduce the signs and symptoms of congestion. Loop diuretics, however, may be associated with increased morbidity and mortality because of deleterious effects on neurohormonal activation, electrolyte balance, and cardiac and renal function. Ultrafiltration, an alternative method of sodium and water removal, safely improves hemodynamics in heart failure patients.

RECENT FINDINGS

The Ultrafiltration versus Intravenous Diuretics for Patients Hospitalized for Acute Decompensated Heart Failure trial has recently shown that among 200 volume overloaded heart failure patients randomized to ultrafiltration or intravenous diuretics, 48 h weight (P = 0.001) and net fluid loss (P = 0.001) were greater in the ultrafiltration group. Dyspnea scores were similar. At 90 days, the ultrafiltration group had fewer heart failure rehospitalizations/patient (P = 0.022) and patients presenting for unscheduled visits (21 vs. 44%; P = 0.009). No serum creatinine differences occurred between the groups.

SUMMARY

In decompensated heart failure, ultrafiltration safely produces greater weight and fluid loss than intravenous diuretics, reduces rehospitalization rates for heart failure and is an effective alternative therapy.

The role of ultrafiltration in the management of heart failure

In the United States, 90% of one million annual hospitalizations for heart failure are due to symptoms of volume overload. Hypervolemia contributes to heart failure progression and mortality. Treatment guidelines recommend that therapy for patients with heart failure be aimed at achieving euvolemia. Intravenous loop diuretics induce a rapid diuresis that reduces lung congestion and dyspnea. However, loop diuretics' effectiveness declines with repeated exposure. Unresolved congestion may contribute to high re-hospitalization rates. Furthermore, loop diuretics may be associated with increased morbidity and mortality due to deleterious effects on neurohormonal activation, electrolyte balance, and cardiac and renal function. Ultrafiltration is an alternative method of sodium and water removal, which safely improves hemodynamics in patients with heart failure. Application of this technology has been limited by the need for high flow rates, large extracorporeal blood volumes, and large-bore central venous catheters. A modified ultrafiltration device has overcome these limitations. Ultrafiltration may be a safe and effective alternative to intravenous diuretics in the treatment of decompensated heart failure.

Management of diuretic-refractory, volume-overloaded patients with acutely decompensated heart failure

Fluid overload is a common presentation for decompensated heart failure, yet management strategies are poorly defined because of relatively few randomized clinical trials that delineate an optimal strategy. Patients refractory to diuretic therapy may be considered for treatment with inotropes or vasodilators, and others may be considered for venovenous ultrafiltration. The rationale for use of each therapy is reviewed.

Refractory congestive heart failure: overview and application of extracorporeal ultrafiltration

Congestive heart failure (CHF) from ischemic cardiomyopathy has emerged as an epidemic health problem. The pathogenesis of CHF is characterized by heightened activity of many neuroendocrine factors, including norepinephrine, angiotensin II, and arginine vasopressin, which lead to heightened systemic vascular resistance and further impedance of left ventricular ejection. Once CHF reaches New York Heart Association (NYHA) class III or IV with heightened activity of the many neurohumoral factors, it tends to be refractory to conventional therapy of vasodilators, inotropic agents, and diuretics. Treatment of refractory CHF appears to require a break in the neurohumoral hemodynamic vicious cycle, and ultrafiltration appears able to produce this interruption. Ultrafiltration has been shown to be successful in patients with NYHA class III to VI CHF and urine output less than 1,000 mL/d. It relieves pulmonary edema, reduces ascites and peripheral edema, and enhances the response to subsequent diuretic therapy. In patients with refractory CHF, the ability to provide adequate volume removal, thus improving overall volume status, normalizing filling pressures, and reducing clinical symptoms, offers an improvement in overall quality of life. Early results have shown that ongoing therapy actually may be associated with decreased hospital readmissions or, at the very least, shortened intensive care unit length of stay.