Intermittent Occlusion of the Superior Vena Cava to Improve Hemodynamics in Patients With Acutely Decompensated Heart Failure: The VENUS-HF Early Feasibility Study

Cardio-Renal Syndrome: Latest Developments in Device-Based Therapy

Background: Cardio-renal syndrome (CRS) is a complex condition involving bidirectional dysfunction of the heart and kidneys, in which the failure of one organ exacerbates failure in the other. Traditional pharmacologic treatments are often insufficient to manage the hemodynamic and neurohormonal abnormalities underlying CRS, especially in cases resistant to standard therapies. Device-based therapies have emerged as a promising adjunct or alternative approach, offering targeted intervention to relieve congestion, improve renal perfusion, and modulate hemodynamics. This study aimed to evaluate the efficacy and safety of various device-based therapies in CRS management, utilizing DRI2P2S classification to categorize interventions as dilators, reducers, interstitial modulators, pullers, pushers, and shifters. Methods: A comprehensive analysis of clinical trial data and observational studies involving device-based therapies in patients with CRS was conducted, with a focus on hemodynamic endpoints, renal and cardiac function, symptom relief, and adverse events. Devices included in the analysis were splanchnic denervation systems (dilators), devices for central and pulmonary pressure reduction (reducers), and systems targeting interstitial fluid (fluid shifters), among others. A systematic literature review from 2004 to 2024 was performed using databases including PubMed, Embase, and ClinicalTrials.gov, following PRISMA guidelines for study selection. Data were extracted on patient demographics, device type, trial design, outcomes, and follow-up duration. Results: Device-based therapies demonstrated varying levels of efficacy in CRS, with significant improvements observed in specific parameters. Notable results were a reduction in central venous pressure and improved diuretic responsiveness in acute CRS cases, while also stabilizing or improving renal function. Other relevant endpoints were fewer heart failure hospitalizations and a reduction in renal adverse events, reduced tissue congestion and improved quality of life scores. However, some devices presented challenges, including procedure-related complications and a learning curve for optimal device implantation. Conclusions: Device-based therapies offer a valuable addition to the CRS treatment paradigm, particularly in cases unresponsive to conventional diuretics and other pharmacologic measures. Each of them addresses specific pathophysiological components of CRS and shows promise in improving clinical outcomes. Nevertheless, further large-scale, long-term trials with comprehensive endpoints are needed to establish these therapies' roles in standard care and to optimize patient selection criteria. Enhanced understanding of device mechanisms and refinement of trial endpoints will be key to maximizing the impact of these therapies on quality of life and clinical outcomes for CRS patients.

Acute Cardiorenal Syndrome: An Update

The complex dynamic pathophysiological interplay between the heart and kidney causes a vicious cycle of worsening renal and/or cardiovascular function. Acute decompensated heart failure causing worsening renal function defines Type 1 cardiorenal syndrome (CRS). Altered hemodynamics coupled with a multitude of nonhemodynamic factors namely pathological activation of the renin angiotensin aldosterone system and systemic inflammatory pathways mechanistically incite CRS type 1. A multipronged diagnostic approach utilizing laboratory markers, noninvasive and/or invasive modalities must be implemented to enable timely initiation of effective treatment strategies. In this review, we discuss the pathophysiology, diagnosis, and emerging treatment options for CRS type 1.

Mechanical Preload Reduction: Harnessing a Cornerstone of Heart Failure Management to Improve Clinical Outcomes

Decongestion is a cornerstone therapeutic goal for those presenting with decompensated heart failure. Current approaches to clinical decongestion include reducing cardiac preload, which is typically limited to diuretics and hemofiltration. Several new technologies designed to mechanically reduce cardiac preload are in development. In this review, we discuss the pathophysiology of decompensated heart failure; the central role of targeting cardiac preload; emerging mechanical preload reduction technologies; and potential application of these devices.

Procedural Insights and Clinical Outcomes of a Novel Superior Vena Cava Occlusion Device for Acute Heart Failure: A Single-Center Experience

The preCARDIA system is a device combining a balloon-mounted catheter and an extracorporeal system designed for intermittent occlusion of the superior vena cava. Studies have established safety and efficacy in acute decompensated heart failure. We present a single-center experience detailing 90 days outcomes and procedural insights. A 24 hours therapy session demonstrated reduced pulmonary wedge pressures and increased urine output, with cardiac output remaining unchanged. There was one readmission and no heart failure-related readmissions at 90 days. The preCARDIA device appears to be a safe mechanical diuretic strategy to manage patients with acute decompensated heart failure beyond current therapeutic strategies.

Emerging devices for heart failure management

There have been significant advances in the treatment of heart failure (HF) in recent years, driven by significant strides in guideline-directed medical therapy (GDMT). Despite this, HF is still associated with high levels of morbidity and mortality, and most patients do not receive optimal medical therapy. In conjunction with the improvement of GDMT, novel device therapies have been developed to better treat HF. These devices include technology capable of remotely monitoring HF physiology, devices that modulate the autonomic nervous system, and those that structurally change the heart with the ultimate aim of addressing the root causes of HF physiology As these device therapies gradually integrate into the fabric of HF patient care, it becomes increasingly important for modern cardiologists to become familiar with them. Hence, the objective of this review is to shed light on currently emerging devices for the treatment of HF.

Preload Reduction Therapies in Heart Failure

Preload reserve represents an important concept in the normal physiologic responses of the body to meet the changing metabolic demands. The recruitment of preload in healthy patients leads to an increase in effective circulating blood volume with a concomitant increase in cardiac output. However, in the setting of heart failure (HF), preload augmentation may precipitate HF decompensation. In this review, we focus on the role of splanchnic nerve modulation and pharmacological therapeutic interventions to prevent HF decompensation through preload reduction. Furthermore, we explore the emerging device-based approaches for cardiac preload reduction while reviewing the ongoing clinical trials.

Innovative Device-Based Strategies for Managing Acute Decompensated Heart Failure

Acute decompensated heart failure (ADHF) is a major cause of hospitalizations in older adults, leading to high mortality, morbidity, and healthcare costs. To address the persistent poor outcomes in ADHF, novel device-based approaches targeting specific pathophysiological mechanisms are urgently needed. The recently introduced DRI2P2S classification categorizes these innovative therapies based on their mechanisms. Devices include dilators (increasing venous capacitance), removers (directly removing sodium and water), inotropes (enhancing left ventricular contractility), interstitials (accelerating lymph removal), pushers (increasing renal arterial pressure), pullers (decreasing renal venous pressure), and selective drippers (selective intrarenal drug infusion). Some are tailored for chronic HF, while others focus on the acute setting. Most devices are in early development, necessitating further research to understand mechanisms, assess clinical effectiveness, and ensure safety before routine use in ADHF management. Exploring these innovative device-based strategies may lead to improved outcomes and revolutionize HF treatment in the future.

Emerging Device Therapies for Cardiorenal Syndrome

While the existence of cardiorenal perturbations has been known for nearly 2 centuries, only in the past 2 decades has significant progress been made in classifying these alterations and characterizing the pathobiology and hemodynamic signature of cardiorenal syndrome (CRS). Empiric intravenous diuretic therapy with fluid and sodium restriction and selective use of vasoactive agents have remained cornerstones of managing acute heart failure with or without acute CRS; however, recent clinical data has exposed the shortcomings of this approach. The traditional view of CRS has long focused on low cardiac output with resultant renal arterial hypoperfusion as the central hemodynamic derangement but this too, has been challenged by new preclinical and clinical observations. Renal venous congestion/hypertension has since been identified as an important hemodynamic contributor to the development of CRS, resulting in diminished renal perfusion pressure, defined as the difference between arterial driving pressure and renal venous pressure. Novel circulatory renal assist devices for the treatment of acute (type I) CRS are in development and may be divided into 2 broad categories: "pushers" which aim to improve renal arterial perfusion (renal preload) and "pullers" which are designed to reduce renal venous congestion (renal afterload). Numerous devices have shown promise in early-stage clinical studies but none have been approved yet for commercial use in the United States. The value of CRS device therapies will ultimately rest on safety as well as the ability of these devices to effect predictable, meaningful, and durable improvements in renal function along with clinical and hemodynamic markers of congestion.

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.

Patients hospitalized with acute heart failure, worsening renal function, and persistent congestion are at high risk for adverse outcomes despite current medical therapy

INTRODUCTION

Approximately 1/3 of patients with acute decompensated heart failure (ADHF) are discharged with persistent congestion. Worsening renal function (WRF) occurs in approximately 50% of patients hospitalized for ADHF and the combination of WRF and persistent congestion are associated with higher risk of mortality and HF readmissions.

METHODS

We designed a multicenter, prospective registry to describe current treatments and outcomes for patients hospitalized with ADHF complicated by WRF (defined as a creatinine increase ≥0.3 mg/dL) and persistent congestion at 96 h. Study participants were followed during the hospitalization and through 90-day post-discharge. Hospitalization costs were analyzed in an economic substudy.

RESULTS

We enrolled 237 patients hospitalized with ADHF, who also had WRF and persistent congestion. Among these, the average age was 66 ± 13 years and 61% had a left ventricular ejection fraction (LVEF) ≤ 40%. Mean baseline creatinine was 1.7 ± 0.7 mg/dL. Patients with persistent congestion had a high burden of clinical events during the index hospitalization (7.6% intensive care unit transfer, 2.1% intubation, 1.7% left ventricular assist device implantation, and 0.8% dialysis). At 90-day follow-up, 33% of patients were readmitted for ADHF or died. Outcomes and costs were similar between patients with reduced and preserved LVEF.

CONCLUSIONS

Many patients admitted with ADHF have WRF and persistent congestion despite diuresis and are at high risk for adverse events during hospitalization and early follow-up. Novel treatment strategies are urgently needed for this high-risk population.

Device-based therapies for decompensated heart failure

PURPOSE OF REVIEW

Despite improvements in medical therapies, patients with heart failure continue to suffer significant morbidity and mortality. Acute decompensated heart failure (ADHF) remains a common and serious medical condition with a myriad of implications on patient survival and quality of life, and heart failure related readmissions persist [1-3].

RECENT FINDINGS

From the detection of prehospitalization decompensation and inpatient management of ADHF to stabilization of cardiogenic shock and durable mechanical circulatory support, device-based therapies are utilized across the spectrum of heart failure management. At present, there are numerous device-based therapies commonly used in clinical practice and many more devices in the early clinical-trial phase aimed at attenuation of ADHF.

SUMMARY

In this review, we examine recent updates in the breadth and use of devices-based therapies in these three main domains: ambulatory heart failure, acute decompensated heart failure, and cardiogenic shock. Device-based therapies for decompensated heart failure will continue to grow in number, indication, and complexity, making recognition and familiarity with available technologies of increased importance for research and clinical practice.

Advances in novel devices for the treatment of heart failure

Heart failure (HF) is one of the leading causes of global health impairment. Current drugs are still limited in their effectiveness in the treatment and reversal of HF: for example, drugs for acute HF (AHF) help to reduce congestion and relieve symptoms, but they do little to improve survival; most conventional drugs for HF with preserved ejection fraction (HFpEF) do not improve the prognosis; and drugs have extremely limited effects on advanced HF. In recent years, progress in device therapies has bridged this gap to a certain extent. For example, the availability of the left ventricular assist device has brought new options to numerous advanced HF patients. In addition to this recognizable device, a range of promising novel devices with preclinical or clinical trial results are emerging that seek to treat or reverse HF by providing circulatory support, repairing structural abnormalities in the heart, or providing electrical stimulation. These devices may be useful for the treatment of HF. In this review, we summarized recent advances in novel devices for AHF, HFpEF, and HF with reduced ejection fraction (HFrEF) with the aim of providing a reference for clinical treatment and inspiration for novel device development.

Device-based therapy for decompensated heart failure: An updated review of devices in development based on the DRI2P2S classification

Congestive heart failure (HF) is a devastating disease leading to prolonged hospitalization, high morbidity and mortality rates, and increased costs. Well-established treatments for decompensated or unstable patients include medications and mechanical cardiac support devices. For acute HF decompensation, new devices are being developed to help relieve symptoms and recover heart and renal function in these patients. A recent device-based classification scheme, collectively classified as DRI2P2S, has been proposed to better describe these new device-based therapies based on their mechanism: dilators (increase venous capacitance), removers (direct removal of sodium and water), inotropes (increase left ventricular contractility), interstitials (accelerate removal of lymph), pushers (increase renal arterial pressure), pullers (decrease renal venous pressure), and selective (selective intrarenal drug infusion). In this review, we describe the new class of medical devices with the most current results reported in preclinical models and clinical trials.

Modern Approaches for the Treatment of Heart Failure: Recent Advances and Future Perspectives

Heart failure (HF) is a progressively deteriorating medical condition that significantly reduces both the patients' life expectancy and quality of life. Even though real progress was made in the past decades in the discovery of novel pharmacological treatments for HF, the prevention of premature deaths has only been marginally alleviated. Despite the availability of a plethora of pharmaceutical approaches, proper management of HF is still challenging. Thus, a myriad of experimental and clinical studies focusing on the discovery of new and provocative underlying mechanisms of HF physiopathology pave the way for the development of novel HF therapeutic approaches. Furthermore, recent technological advances made possible the development of various interventional techniques and device-based approaches for the treatment of HF. Since many of these modern approaches interfere with various well-known pathological mechanisms in HF, they have a real ability to complement and or increase the efficiency of existing medications and thus improve the prognosis and survival rate of HF patients. Their promising and encouraging results reported to date compel the extension of heart failure treatment beyond the classical view. The aim of this review was to summarize modern approaches, new perspectives, and future directions for the treatment of HF.

Novel Therapeutic Devices in Heart Failure

Heart failure (HF) constitutes a significant clinical problem and is associated with a sizeable burden for the healthcare system. Numerous novel techniques, including device interventions, are investigated to improve clinical outcome. A review of the most notable currently studied devices targeting pathophysiological processes in HF was performed. Interventions regarding autonomic nervous system imbalance, i.e., baroreflex activation therapy; vagus, splanchnic and cardiopulmonary nerves modulation; respiratory disturbances, i.e., phrenic nerve stimulation and synchronized diaphragmatic therapy; decongestion management, i.e., the Reprieve system, transcatheter renal venous decongestion system, Doraya, preCardia, WhiteSwell and Aquapass, are presented. Each segment is divided into subsections: potential pathophysiological target, existing evidence and weaknesses or unexplained issues. Novel therapeutic devices represent great potential in HF therapy management; however, further evidence is necessary to fully evaluate their utility.

Targeting Preload in Heart Failure: Splanchnic Nerve Blockade and Beyond

Preload augmentation represents a critical mechanism for the cardiovascular system to increase effective circulating blood volume to increase cardiac filling pressures and, subsequently, for the heart to increase cardiac output. The splanchnic vascular compartment is the primary source of vascular capacity and thus the primary target for preload recruitment in humans. Under normal conditions, sympathetic stimulation of these primary venous vessels promotes the shift of blood from the splanchnic to the thoracic compartment and elevates preload and cardiac output. However, in heart failure, since filling pressures may be elevated at rest due to decreased venous capacitance, incremental recruitment of preload to enhance cardiac output may exacerbate congestion and limit exercise capacity. Accordingly, recent attention has focused on therapies designed to regulate splanchnic vascular redistribution to improve cardiac filling pressures and patient-centered outcomes such as quality of life and exercise capacity in patients with heart failure. In this review, we discuss the relevance of splanchnic circulation as a venous reservoir, the contribution of stressed blood volume to heart failure pathogenesis, and the implications for pharmacological therapeutic interventions to prevent heart failure decompensation. Further, we review emerging device-based approaches for cardiac preload reduction such as partial/complete occlusion of the superior vena cava or the inferior vena cava.