Rationale and design of the Aquapheresis Versus Intravenous Diuretics and Hospitalization for Heart Failure (AVOID-HF) trial

Outcomes of Ultrafiltration in community-based hospitals

OBJECTIVE

We sought to examine outcomes of ultrafiltration in real world community-based hospital settings.

BACKGROUND

Ultrafiltration (UF) is an accepted therapeutic option for advanced decompensated heart failure (ADHF). the feasibility of UF in a community hospital setting, by general cardiologists in a start-up program had not been objectively evaluated.

METHODS

We retrospectively analyzed the first-year cohort of ADHF patients treated with UF from 10/1/2019 to 10/1/2020, which totaled 30 patients, utilizing the CHF Solutions Aquadex FlexFlow™ System with active UF rate titration.

RESULTS

Baseline patient characteristics were similar to RCTs: mean age 63, 73 % male; 27 % female; 53 % Caucasian; 47 % African American; 77 % had LVEF ≤ 40. The baseline mean serum creatinine (Cr) was 1.84 ±0.62 mg/dL, mean GFR of 36.95 ±9.60 ml/min. HF re-admission rates were not significantly different than prior studies (17.2 % at 30 d, 23.3 % at 60 d, but in our cohort, per patient HF re-admission rates were reduced significantly by 60 d (0.30 p = 0.017).

CONCLUSION

Our analysis showed success with UF in mainstream setting with reproducible results of significant volume loss without adverse renal effect, mitigation of recurrent Hdmissions, and remarkable subjective clinical benefit.

Congestion in Heart Failure: From the Secret of a Mummy to Today's Novel Diagnostic and Therapeutic Approaches: A Comprehensive Review

This review paper presents a review of the evolution of this disease throughout the centuries, describes and summarizes the pathophysiologic mechanisms, briefly discusses the mechanism of action of diuretics, presents their role in decongesting heart failure in patients, and reveals the data behind ultrafiltration in the management of acutely or chronically decompensated heart failure (ADHF), focusing on all the available data and advancements in this field. Acutely decompensated heart failure (ADHF) presents a critical clinical condition characterized by worsening symptoms and signs of heart failure, necessitating prompt intervention to alleviate congestion and improve cardiac function. Diuretics have traditionally been the mainstay for managing fluid overload in ADHF. Mounting evidence suggests that due to numerous causes, such as coexisting renal failure or chronic use of loop diuretics, an increasing rate of diuretic resistance is noticed and needs to be addressed. There has been a series of trials that combined diuretics of different categories without the expected results. Emerging evidence suggests that ultrafiltration may offer an alternative or adjunctive approach.

Ultrafiltration in Heart Failure: A Review

Ultrafiltration is an effective method to get rid of fluid retention and congestion in patients with acute decompensated heart failure (HF) without affecting the circulating volume. Although its efficacy in comparison to diuretics is debatable, the evaluation of our analysis is based on various studies that comprise published clinical trials on ultrafiltration and studies comparing the efficacy of diuretics and ultrafiltration. Apart from this, we also look at literature that provides shortcomings of the said procedure and its scope for future advancements. Heart failure ultimately leads to volume overload, which is a highly concerning complication. Diuretics have been used as a first-line treatment for fluid overload but are becoming inefficacious due to the development of resistance and renal dysfunction. Ultrafiltration, on the other hand, is an attractive alternative to counter volume overload and congestion, which are unresponsive to medical therapy. There is also evidence that it significantly decreases the probability of future episodes of decompensation. There are, however, disagreements about whether ultrafiltration is an effective method to improve mortality in these patients. There is a lack of conclusive studies demonstrating the superiority of one fluid removal method over another. Hence, it is imperative to continue searching for the most effective method to treat congestion. Priority should be given to more mechanistic studies regarding ultrafiltration.

Benefits of peritoneal ultrafiltration in HFpEF and HFrEF patients

Background

Peritoneal ultrafiltration (pUF) in refractory heart failure (HF) reduces the incidence of decompensation episodes, which is of particular significance as each episode incrementally adds to mortality. Nevertheless, there are insufficient data about which patient cohort benefits the most. The objective of this study was to compare pUF in HFrEF and HFpEF, focusing on functional status, hospitalizations, surrogate endpoints and mortality.

Methods

This study involves 143 patients, who could be classified as either HFpEF (n = 37, 25.9%) or HFrEF (n = 106, 74.1%) and who received pUF due to refractory HF.

Results

Baseline eGFR was similar in HFrEF (23.1 ± 10.6 mg/dl) and HFpEF (27.8 ± 13.2 mg/dl). Significant improvements in NYHA class were found in HFpEF (3.19 ± 0.61 to 2.72 ± 0.58, P <  0.001) and HFrEF (3.45 ± 0.52 to 2.71 ± 0.72, P <  0.001). CRP decreased in HFrEF (19.4 ± 17.6 mg/l to 13.7 ± 21.4 mg/l, P = 0.018) and HFpEF (33.7 ± 52.6 mg/l to 17.1 ± 26.3 mg/l, P = 0.004). Body weight was significantly reduced in HFrEF (81.1 ± 14.6 kg to 77.2 ± 15.6 kg, P = 0.003) and HFpEF (86.9 ± 15.8 kg to 83.1 ± 15.9 kg, P = 0.005). LVEF improved only in HFrEF (25.9 ± 6.82% to 30.4 ± 12.2%, P = 0.046). BCR decreased significantly in HFrEF and HFpEF (55.7 ± 21.9 to 34.3 ± 17.9 P > 0.001 and 50.5 ± 68.9 to 37.6 ± 21.9, P = 0.006). Number of hospitalization episodes as well as number of hospitalization days decreased significantly only in HFpEF (total number 2.88 ± 1.62 to 1.25 ± 1.45, P <  0.001, days 40.4 ± 31.7 to 18.3 ± 22.5 days, P = 0.005).

Conclusions

pUF offers various benefits in HFpEF and HFrEF, but there are also substantial differences. In particular, hospitalization rates were found to be significantly reduced in HFpEF patients, indicating a greater medical and economical advantage. However, LVEF was only found to be improved in HFrEF patients. While pUF can now be regarded as an option to supplement classical HF therapy, further studies are desirable to obtain specifications about pUF in HFpEF, HFmEF and HFrEF patients.

The Cardiorenal Syndrome in Heart Failure

Abnormal fluid handling leads to physiologic abnormalities in multiple organ systems. Deranged hemodynamics, neurohormonal activation, excessive tubular sodium reabsorption, inflammation, oxidative stress, and nephrotoxic medications are important drivers of harmful cardiorenal interactions in patients with heart failure. Accurate quantitative measurement of fluid volume is vital to individualizing therapy for such patients. Blood volume analysis and pulmonary artery pressure monitoring seem the most reliable methods for assessing fluid volume and guiding decongestive therapies. Still the cornerstone of decongestive therapy, diuretics' effectiveness decreases with progression of heart failure. Extracorporeal ultrafiltration, an alternative to diuretics, has been shown to reduce heart-failure events.

Peritoneal dialysis as therapeutic option in heart failure patients

Aims

Each episode of acute decompensated heart failure (HF) incrementally adds to mortality. Peritoneal dialysis (PD) offers an alternative therapeutic option in refractory HF and reduces the incidence of decompensation episodes. The objective of this study was to determine the efficacy of PD, in terms of functional status, surrogate endpoints, rate of hospitalizations, and mortality.

Methods and results

This study is based on the registry of the German Society of Nephrology, involving 159 patients receiving PD treatment due to refractory HF between January 2010 and December 2014. Body weight was reduced by PD (82.2 ± 14.9 to 78.4 ± 14.8 kg, P < 0.001), and significant improvements in New York Heart Association functional class (3.38 ± 0.55 to 2.85 ± 0.49, P < 0.001) were found already after 3 months. Left ventricular ejection fraction did not change (31.5 ± 13.8 to 34.0 ± 15.7%, P = 0.175). C‐reactive protein improved with PD treatment (33.7 ± 52.6 to 17.1 ± 26.3 mg/L, P = 0.004). Blood urea nitrogen/creatinine ratio decreased significantly (148.7 ± 68.3 to 106.7 ± 44.8 mg/dL, P < 0.001). Hospitalization rates decreased significantly (total number 2.86 ± 1.88 to 1.90 ± 1.78, P = 0.001, and 39.2 ± 30.7 to 27.1 ± 25.2 days, P = 0.004). One year mortality was 39.6% in end‐stage HF patients treated with PD.

Conclusions

Peritoneal dialysis offers an additional therapeutic option in end‐stage HF and is associated with improved New York Heart Association classification and reduced hospitalization. Although PD treatment was associated with various benefits, further studies are necessary to identify which patients benefit the most from PD.

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.

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.

Editor's Choice-Diuretic resistance in acute heart failure

Diuretic resistance is a powerful predictor of adverse outcome in acute heart failure (AHF), irrespectively of underlying glomerular filtration rate. Metrics of diuretic efficacy such as natriuresis, urine output, weight loss, net fluid balance, or fractional sodium excretion, differ in their risk for measurement error, convenience, and biological plausibility, which should be taken into account when interpreting their results. Loop diuretic resistance in AHF has multiple causes including altered drug pharmacokinetics, impaired renal perfusion and effective circulatory volume, neurohumoral activation, post-diuretic sodium retention, the braking phenomenon and functional as well as structural adaptations in the nephron. Ideally, these mechanisms should guide specific treatment decisions with the goal of achieving complete decongestion. Therefore, volume overload needs to be identified correctly to avoid poor diuretic response due to electrolyte depletion or dehydration. Next, renal perfusion should be optimised if possible and loop diuretics should be prescribed above their threshold dose. Addition of thiazide-type diuretics should be considered when a progressive decrease in loop diuretic efficacy is observed with prolonged use (i.e., the braking phenomenon). Furthermore, thiazide-type diuretics are a useful addition in patients with low glomerular filtration rate. However, they limit free water excretion and are relatively contraindicated in cases of hypotonic hyponatremia, where acetazolamide is the better option. Finally, ultrafiltration should be considered in patients with refractory diuretic resistance as persistent volume overload after decongestive treatment is associated with worse outcomes. Whether more upfront use of any of these individually tailored decongestion strategies is superior to monotherapy with loop diuretics remains to be shown by adequately powered randomised clinical trials.

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.

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.

Management of Congestion and Diuretic Resistance in Heart Failure

We present the case of a patient with heart failure and severe congestion who was responding poorly to diuretic therapy. We discuss the key problems concerning the pathophysiology and bedside therapeutic approach to congestion and fluid overload in this clinical setting, and we give practical suggestions to overcome congestion, especially in the setting of diuretic resistance and worsening renal function. We conclude that the application of key pharmacokinetic and pharmacodynamic principles of diuretic therapy, along with in-depth knowledge of the pathophysiology of heart failure, still represent the cornerstones for a correct approach to decongestive therapy in these patients.

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.

"AVOID"ing harm by a double-edged sword: is there a role for ultrafiltration in heart failure?

Prior studies comparing ultrafiltration with medical management for acute decompensated heart failure have yielded conflicting results. The AVOID-HF trial was designed as a definitive comparison of optimal ultrafiltration versus optimal diuretic-based medical therapy; unfortunately, the trial was terminated prematurely because of slow recruitment. The results of AVOID-HF nevertheless provide a rationale for well-designed, adequately powered trials to determine whether ultrafiltration has a role in the routine management of acute decompensated heart failure.

Management of Cardio-Renal Syndrome and Diuretic Resistance

OPINION STATEMENT

Diuretic resistance in acute heart failure has emerged as a powerful predictor of adverse outcome, which is often independent of underlying glomerular filtration rate (GFR). Metrics of diuretic efficacy differ in their accuracy, convenience, and biological plausibility, which should be taken into account when interpreting their results. Loop diuretic efficacy depends on adequate delivery of both the pharmacological agent itself and its substrate (i.e., sodium chloride) to the loop diuretic site of action at the luminal side of the thick ascending limb of Henle's loop. This requires an adequate dosing strategy, with higher doses needed when GFR is low. Importantly, the kidneys are able only to regulate the effective circulatory volume. Thus, specific problems of intravascular volume depletion and poor cardiac output with impaired renal perfusion should be addressed. Addition of thiazide-type diuretics should be considered when a progressive decrease in loop diuretic efficacy is observed with prolonged use (i.e., the braking phenomenon). Furthermore, thiazide-type diuretics are a useful addition in patients with low GFR to maximally boost fractional sodium excretion when nephron perfusion is poor. However, thiazide-type diuretics limit free water excretion and should be withheld in cases of hypotonic hyponatremia. Mineralocorticoid receptor antagonists (MRA) and acetazolamide are interesting options to increase loop diuretic efficacy, but further study is needed to assess whether improved diuretic efficacy also translates into clinical outcome benefits. Finally, ultrafiltration should be considered in patients with refractory diuretic resistance as persistent volume overload after decongestive treatment is associated with worse outcomes. Whether more upfront use of individually tailored ultrafiltration is superior to pharmacological therapy remains to be shown by adequately powered randomized clinical trials.

Extracorporeal ultrafiltration therapy for acute decompensated heart failure

Congestion is the most common reason for hospitalization of patients with acute decompensated heart failure (ADHF) and adversely impacts their outcomes. Extracorporeal ultrafiltration (UF) therapy has re-emerged as an effective strategy for decongestion in this setting. This article is intended to discuss key concepts in UF and its technique, provide a brief historical view of UF application for decongestion in ADHF, review the hemodynamic and neurohormonal effects of UF and their positive effects on the pathophysiology of ADHF, discuss the findings of the landmark trials in this field, and explain key findings of these studies as well as the apparent discrepancies in their findings. In a separate section we discuss the intricacies of renal dysfunction in ADHF as it plays a very important role in understanding the current evidence and designing futures clinical trials of UF in ADHF. In the end, the authors provide their perspective on the future role of UF in management of patients with ADHF and congestion.