Left atrial decompression through unidirectional left-to-right interatrial shunt for the treatment of left heart failure: first-in-man experience with the V-Wave device

Design and Rationale of the V-Wave Shunt MitraClip Study

Heart failure (HF) and moderate-to-severe mitral regurgitation (MR) with residual elevations in left atrial pressure (LAP) after MitraClip may remain symptomatic and experience subsequent HF readmissions. The V-Wave interatrial shunt system is a permanent interatrial septal implant that shunts blood from the left-to-right atrium and serves to continuously unload the left atrium. Although the V-Wave shunt has previously been studied in patients with HF, the safety and feasibility of its deployment at the time of the MitraClip procedure is unknown. The V-Wave Shunt MitraClip Study (NCT04729933) is an early feasibility study that aims to demonstrate the safety and efficacy of implantation of the V-Wave shunt device at the time of MitraClip procedure. Patients with moderate-to-severe secondary MR with left ventricular ejection fraction 20% to 50% and New York Heart Association functional class III/IV symptoms despite optimal medical therapy, residual mean LAP ≥20 mm Hg after MitraClip, and mean LAP-right atrial pressure difference ≥5 mm Hg are included. The primary safety end point is a composite outcome of all-cause death, stroke, myocardial infarction device embolization, cardiac tamponade, or device-related re-intervention or surgery at 30 days. Patients will be followed up to 5 years. Enrollment is ongoing, with 30-day results expected by the end of 2024. The V-Wave Shunt Mitraclip Study aims to demonstrate the safety and efficacy of the implantation of the V-Wave interatrial shunt device at the time of index MitraClip placement which may serve as an adjunctive method by which continuous left atrial unloading may be achieved.

MEMS Technology in Cardiology: Advancements and Applications in Heart Failure Management Focusing on the CardioMEMS Device

Heart failure (HF) is a complex clinical syndrome associated with significant morbidity, mortality, and healthcare costs. It is characterized by various structural and/or functional abnormalities of the heart, resulting in elevated intracardiac pressure and/or inadequate cardiac output at rest and/or during exercise. These dysfunctions can originate from a variety of conditions, including coronary artery disease, hypertension, cardiomyopathies, heart valve disorders, arrhythmias, and other lifestyle or systemic factors. Identifying the underlying cause is crucial for detecting reversible or treatable forms of HF. Recent epidemiological studies indicate that there has not been an increase in the incidence of the disease. Instead, patients seem to experience a chronic trajectory marked by frequent hospitalizations and stagnant mortality rates. Managing these patients requires a multidisciplinary approach that focuses on preventing disease progression, controlling symptoms, and preventing acute decompensations. In the outpatient setting, patient self-care plays a vital role in achieving these goals. This involves implementing necessary lifestyle changes and promptly recognizing symptoms/signs such as dyspnea, lower limb edema, or unexpected weight gain over a few days, to alert the healthcare team for evaluation of medication adjustments. Traditional methods of HF monitoring, such as symptom assessment and periodic clinic visits, may not capture subtle changes in hemodynamics. Sensor-based technologies offer a promising solution for remote monitoring of HF patients, enabling early detection of fluid overload and optimization of medical therapy. In this review, we provide an overview of the CardioMEMS device, a novel sensor-based system for pulmonary artery pressure monitoring in HF patients. We discuss the technical aspects, clinical evidence, and future directions of CardioMEMS in HF management.

Interatrial Shunt Devices

Elevated left atrial pressure during exercise is a hallmark of heart failure (HF) and is associated with adverse left atrial remodeling and poor outcomes. To decompress the pressure-overloaded left atrium in patients with HF, several device-based approaches have been developed to create a permanent, pressure-dependent, left-to-right interatrial shunt. Such approaches are currently in various stages of investigations in both HF with reduced ejection fraction (EF) and HF with preserved EF. This review discusses the evolution of the concept of left atrial decompression and summarizes the current landscape of device-based approaches used for left atrial decompression.

Percutaneous Strategies in Structural Heart Diseases: Focus on Chronic Heart Failure

BACKGROUND

Central Illustration : Percutaneous Strategies in Structural Heart Diseases: Focus on Chronic Heart Failure Transcatheter devices for monitoring and treating advanced chronic heart failure patients. PA: pulmonary artery; LA: left atrium; AFR: atrial flow regulator; TASS: Transcatheter Atrial Shunt System; VNS: vagus nerve stimulation; BAT: baroreceptor activation therapy; RDN: renal sympathetic denervation; F: approval by the American regulatory agency (FDA); E: approval by the European regulatory agency (CE Mark).

BACKGROUND

Innovations in devices during the last decade contributed to enhanced diagnosis and treatment of patients with cardiac insufficiency. These tools progressively adapted to minimally invasive strategies with rapid, widespread use. The present article focuses on actual and future directions of device-related diagnosis and treatment of chronic heart failure.

Device-based percutaneous treatments to decompress the left atrium in heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) accounts for more than half of heart failure hospital admissions in the last years and is burdened by high mortality and poor quality of life. Providing effective management for HFpEF patients is a major unmet clinical need. Increase in left atrial pressure is the key determinant of pulmonary congestion, with consequent dyspnoea and exercise limitation. Evidence on benefits of medical treatment in HFpEF patients is limited. Thus, alternative strategies, including devices able to reduce left atrial pressure, through an interatrial communication determining a left-right shunt, were developed. This review aims to summarize evidence regarding the use of percutaneous interatrial shunting devices. These devices are safe and effective in improving hemodynamic and clinical parameters, including pulmonary capillary wedge pressure, 6-min walking distance, and New York Heart Association functional class. Data on cardiovascular mortality and re-hospitalization for heart failure are still scarce.

Is combined use of radiofrequency ablation and balloon dilation the future of interatrial communications?

INTRODUCTION

Personalized and stable interatrial communication is an important palliative therapy for patients with heart failure. However, this remains a technically challenging task.

AREAS COVERED

In the past decades, substantial advancements in atrial septostomy for the creation of controllable and durable interatrial communication have been made, and numerous novel devices and techniques are in various stages of development. In this review, we discuss the evolving indications for atrial septostomy, current approaches with or without device implantation, and indicators for optimal interatrial communication. The combined use of radiofrequency ablation and balloon dilation (CURB) is an individualized management approach based on underlying hemodynamics, which demonstrates unique advantages in creating a sufficient interatrial communication with satisfactory stability. The advantages and disadvantages of this implant-free procedure are analyzed and its clinical prospects are assessed.

EXPERT OPINION

With ready availability, high safety, and efficacy, CURB is a promising procedure for creating personalized and stable interatrial communication without device implantation. Further research is required to simplify the procedure, screen optimal reference parameters for personalized therapy, and evaluate the long-term outcome in a large population of patients.

Feasibility of a No-Implant Approach to Interatrial Shunts: Preclinical and Early Clinical Studies

Background

Heart failure with preserved ejection fraction represents a major unmet clinical need with limited treatment options. Recent device therapies under investigation have focused on decompression of the left atrium through an implantable interatrial shunt. Although these devices have shown favorable safety and efficacy signals, an implant is required to maintain shunt patency, which may increase the patient risk profile and complicate subsequent interventions requiring transseptal access.

Methods

The Alleviant System is a no-implant approach to creating an interatrial shunt using radiofrequency energy to securely capture, excise, and extract a precise disk of tissue from the interatrial septum. Acute preclinical studies in healthy swine (n = 5) demonstrated the feasibility of the Alleviant System to repeatably create a 7 mm interatrial orifice with minimal collateral thermal effect and minimal platelet and fibrin deposition observed histologically.

Results

Chronic animal studies (n = 9) were carried out to 30- and 60-day time points and exhibited sustained shunt patency with histology demonstrating completely healed margins, endothelialization, and no trauma to adjacent atrial tissue. Preliminary clinical safety and feasibility were validated in a first-in-human study in patients with heart failure with preserved ejection fraction (n = 15). All patients demonstrated shunt patency by transesophageal echocardiographic imaging at 1, 3, and 6 months, as well as cardiac computed tomography imaging at 6-month follow-up timepoints.

Conclusions

Combined, these data support the safety and feasibility of a novel no-implant approach to creating an interatrial shunt using the Alleviant System. Continued follow-up and subsequent clinical studies are currently ongoing.

Haemodynamic changes of interatrial shunting devices for heart failure: a systematic review and meta-analysis

AIMS

To assess the efficacy and safety, primarily in relation to the haemodynamic effects, of interatrial shunting devices (ISD) for the treatment of heart failure (HF), we conducted a systematic review and a meta-analysis.

METHODS AND RESULTS

We used the MEDLINE, Cochrane Library, Embase, and PubMed databases to identify clinical studies (published to 4 August 2021) that evaluated the effect of ISD on HF. The primary endpoint was defined as changes in pulmonary capillary wedge pressure (PCWP). Secondary endpoints included (i) other haemodynamic indexes, including cardiac output (CO), right atrial pressure (RAP), and mean pulmonary artery pressure (mPAP) by right heart catheterization, and (ii) change from baseline in 6 min walk distance (6MWD). After a literature search and detailed evaluation, six trials enrolling a total of 203 individuals were included in the quantitative analysis. Pooled analyses showed that after ISD implantation, PCWP decreased by a mean 3.10 mmHg [95% confidence interval (CI) -4.56 to -1.64; I2  = 0%; P < 0.0001]. Overall, CO increased by 0.77 L/min (95% CI 0.02 to 1.52; P = 0.04; I2  = 82%), but there were no significant changes in RAP or mPAP. The mean 6MWD increased by 32.33 m (95% CI 10.74 to 53.92; P = 0.003; I2  = 0) after ISD implantation.

CONCLUSIONS

Interatrial shunting device can effectively reduce PCWP, increase CO and 6MWD, and has no obvious adverse effects on the right heart and pulmonary pressure. Studies with larger sample size and longer follow-up time are needed for further verification.

Device-Based Solutions to Improve Cardiac Physiology and Hemodynamics in Heart Failure With Preserved Ejection Fraction

Characterized by a rapidly increasing prevalence, elevated mortality and rehospitalization rates, and inadequacy of pharmaceutical therapies, heart failure with preserved ejection fraction (HFpEF) has motivated the widespread development of device-based solutions. HFpEF is a multifactorial disease of various etiologies and phenotypes, distinguished by diminished ventricular compliance, diastolic dysfunction, and symptoms of heart failure despite a normal ejection performance; these symptoms include pulmonary hypertension, limited cardiac reserve, autonomic imbalance, and exercise intolerance. Several types of atrial shunts, left ventricular expanders, stimulation-based therapies, and mechanical circulatory support devices are currently under development aiming to target one or more of these symptoms by addressing the associated mechanical or hemodynamic hallmarks. Although the majority of these solutions have shown promising results in clinical or preclinical studies, no device-based therapy has yet been approved for the treatment of patients with HFpEF. The purpose of this review is to discuss the rationale behind each of these devices and the findings from the initial testing phases, as well as the limitations and challenges associated with their clinical translation.

Device Therapy in Chronic Heart Failure: JACC State-of-the-Art Review

The regulatory landscape for device-based heart failure (HF) therapies has seen a major shift in the last 7 years. In 2013, the U.S. Food and Drug Administration released guidance for early feasibility and first-in-human studies, thereby encouraging device innovation, and in 2016 the U.S. Congress authorized the Breakthrough Devices Program to expedite access for Americans to innovative devices indicated for diagnosis and treatment of serious illnesses, such as HF. Since December 2016, there has been an increase in the number of HF devices for which manufacturers are seeking approval through the breakthrough designation pathway. This has led to a rapid uptake in the development and evaluation of device-based HF therapies. This article reviews the current and future landscape of device therapies for chronic HF and associated comorbidities and the regulatory environment that is driving current and future innovation.

The Effects of Preserving Mitral Valve Function on a Left Atrial Assist Device: An In Vitro Mock Circulation Loop Study

We are developing a left atrial assist device (LAAD) to pump blood from the left atrium to the left ventricle for patients who have heart failure with preserved ejection fraction (HFpEF). This study aimed to assess the hemodynamics with the LAAD implanted at two different levels: the mitral valve (MV) level, after removing the MV; and the supravalvular level, preserving MV function conditions using an in vitro mock circulatory loop. Normal heart and mild, moderate, and severe diastolic heart failure conditions were simulated, and the LAAD was set at three different speeds. Without the LAAD support, cardiac output (CO) decreased from 3.7 to 1.1 L/min, aortic pressure (AoP) decreased from 100 to 33 mm Hg, and left atrial pressure (LAP) increased from 16 to 23 mm Hg as the diastolic function became impaired. With high pump support after removing the MV, CO and AoP readings were comparable with those for preserved MV function (CO reached 3.9-4.1 L/min, AoP reached more than 110 mm Hg, and LAP dropped to 16-17 mm Hg under both conditions at high pump speeds). In the mock circulatory loop, our LAAD appeared to have sufficient ability to maintain the hemodynamic status at both positions.

Current and Future Drug and Device Therapies for Pediatric Heart Failure Patients: Potential Lessons from Adult Trials

This review discusses the potential drug and device therapies for pediatric heart failure (HF) due to reduced systolic function. It is important to realize that most drugs that are used in pediatric HF are extrapolated from adult cardiology practices or consensus guidelines based on expert opinion rather than on evidence from controlled clinical trials. It is difficult to conclude whether the drugs that are well established in adult HF trials are also beneficial for children because of tremendous heterogeneity in the mechanism of HF in children and variations in the pharmacokinetics and pharmacodynamics of drugs from birth to adolescence. The lessons learned from adult trials can guide pediatric cardiologists to design clinical trials of the newer drugs that are in the pipeline to study their efficacy and safety in children with HF. This paper's focus is that the reader should specifically think through the pathophysiological mechanism of HF and the mode of action of drugs for the selection of appropriate pharmacotherapy. We review the drug and device trials in adults with HF to highlight the knowledge gap that exists in the pediatric HF population.

Device-based treatment options for heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) is a syndrome with an unfavorable prognosis, and the number of the patients continues to grow. Because there is no effective therapy established as a standard, including pharmacological treatments, a movement to develop and evaluate device-based therapies is an important emerging area in the treatment of HFpEF patients. Many devices have set their target to reduce the left atrial pressure or pulmonary capillary wedge pressure because they are strongly related to the symptoms and prognosis of HFpEF, but the methodology to achieve it varies based on the devices. In this review, we summarize and categorize these devices into the following: (1) interatrial shunt devices, (2) left ventricle expander, (3) electrical therapy, (4) left ventricular assist devices, and (5) mechanical circulatory support devices under development. Here, we describe the features and specifications of device-based therapies currently under development and those at more advanced stages of preclinical testing. Advantages and limitations of these technologies, with insights on their safety and feasibility for HFpEF patients, are described.

Left atrial assist device function at various heart rates using a mock circulation loop

We are developing a new left atrial assist device (LAAD) for patients who have heart failure with preserved ejection fraction (HFpEF). This study aimed to assess the hemodynamic effects of the LAAD under both normal heart conditions and various diastolic heart failure (DHF) conditions using a mock circulatory loop. A continuous-flow pump that simulates LAAD, was placed between the left atrial (LA) reservoir and a pneumatic ventricle that simulated a native left ventricle on a pulsatile mock loop. Normal heart (NH) and mild, moderate, and severe DHF conditions were simulated by adjusting the diastolic drive pressures of the pneumatic ventricle. With the LAAD running at 3200 rpm, data were collected at 60, 80, and 120 bpm of the pneumatic ventricle. Cardiac output (CO), mean aortic pressure (AoP), and mean LA pressure (LAP) were compared to evaluate the LAAD performance. With LAAD support, the CO and AoP rose to a sufficient level at all heart rates and DHF conditions (CO; 3.4-3.8 L/min, AoP; 90-105 mm Hg). Each difference in the CO and the AoP among various heart rates was minuscule compared with non-pump support. The LAP decreased from 21-23 to 17-19 mm Hg in all DHF conditions (difference not significant). Furthermore, hemodynamic parameters improved for all DHF conditions, independent of heart rate. The LAAD can provide adequate flow to maintain the circulation status at various heart rates in an in vitro mock circulatory loop.

Impact of Interatrial Shunts on Invasive Hemodynamics and Exercise Tolerance in Patients With Heart Failure

Approximately 50% of patients with heart failure have preserved ejection fraction. Although a wide variety of conditions cause or contribute to heart failure with preserved ejection fraction, elevated left ventricular filling pressures, particularly during exercise, are common to all causes. Acute elevation in left-sided filling pressures promotes lung congestion and symptoms of dyspnea, while chronic elevations often lead to pulmonary vascular remodeling, right heart failure, and increased risk of mortality. Pharmacologic therapies, including neurohormonal modulation and drugs that modify the nitric oxide/cyclic GMP-protein kinase G pathway have thus far been limited in reducing symptoms or improving outcomes in patients with heart failure with preserved ejection fraction. Hence, alternative means of reducing the detrimental rise in left-sided heart pressures are being explored. One proposed method of achieving this is to create an interatrial shunt, thus unloading the left heart at rest and during exercise. Currently available studies have shown 3- to 5-mm Hg decreases of pulmonary capillary wedge pressure during exercise despite increased workload. The mechanisms underlying the hemodynamic changes are just starting to be understood. In this review we summarize results of recent studies aimed at elucidating the potential mechanisms of improved hemodynamics during exercise tolerance following interatrial shunt implantation and the current interatrial shunt devices under investigation.

Interatrial Shunting for Treating Acute and Chronic Left Heart Failure

The creation of an interatrial shunt has emerged as a new therapy to decompress the left atrium in patients with acute and chronic left heart failure (HF). Current data support the safety of this therapy, and promising preliminary efficacy results have been reported in patients who are refractory to optimal medical/device therapy. This article aims to provide an updated overview and clinical perspective on interatrial shunting for treating different HF conditions, and highlights the potential challenges and future directions of this therapy.

Antithrombotic/Antiplatelet Treatment in Transcatheter Structural Cardiac Interventions-PFO/ASD/LAA Occluder and Interatrial Shunt Devices

Transcatheter interventions enable safe and efficient treatment of various structural heart diseases. However, therapy does not finished with the end of the procedure. Device thrombosis is a possible serious complication. Therefore, careful patient management should include optimal antiplatelet or antithrombotic medication to enhance safe and complete endothelial coverage of the implanted device. In case of thrombus formation careful diagnostic evaluation and prompt treatment is crucial. This paper provides an update to current knowledge and understanding of prevention and management of device related thrombosis.

Creation of a restrictive atrial left-to-right shunt: a novel treatment for heart failure

Elevated left atrial (LA) filling pressures are associated with poor prognosis in patients with heart failure (HF). Recent evidences have shown that, in this setting, the presence of restrictive small atrial defect may protect from an extreme increase in LA pressure and prevent consecutive pulmonary congestion and acute decompensation, without the expense of an unfavourable significant left-to-right shunt. Therefore, decompression of LA by creating a unidirectional but restrictive left-to-right interatrial shunt has been emerging as a new therapeutic strategy in patients suffering from both HF with preserved and reduced ejection fraction. Two dedicated devices (V-Wave and interatrial septal device system-IASD) are currently available to create a restrictive interatrial communication. Several clinical studies have demonstrated the safety of this approach, with encouraging results regarding the improvements in haemodynamic parameters, functional status and quality of life in treated patients. We aim to summarize the present knowledge concerning this novel therapeutic approach for HF, describe the currently available devices and depict their potential future clinical indications.

Interventional Heart Failure and Hemodynamic Monitoring

Convergence of the fields of heart failure (HF) and interventional cardiology has led to the formation of a discipline referred to as interventional HF. Although the term may be applied to essentially any invasive procedure performed in patients with HF (eg, coronary angiography, percutaneous coronary intervention, invasive assessment of hemodynamics), it is more commonly reserved for the application of invasive diagnostic or therapeutic procedures to improve the clinical decision-making, functional status, and outcomes of HF patients. This article reviews developing modalities.

The Medical Devices Special Access Program in Canada: A Scoping Study

New health technologies enter Canadian healthcare organizations in various ways, and understanding them is essential to the development of a pan-Canadian Health Technology Management (HTM) Strategy, now a priority of governments across Canada. One way is through Health Canada's Medical Devices Special Access Program (MDSAP), which permits unlicensed devices to be obtained by healthcare professionals. However, the circumstances around and implications of the current use of this program are not clear. A scoping literature review was conducted to clarify these and identify important roles and issues related to the MDSAP. Limited information was found on the MDSAP. Nevertheless, three themes demonstrating the roles of the MDSAP in HTM emerged: arbiter in technology selection, a route to technology procurement and facilitator of health technology innovation. No information suggesting that MDSAP is used to circumvent licensing was found. Rather, it enables desired patient outcomes and product commercialization.

Haemodynamic Monitoring Devices in Heart Failure: Maximising Benefit with Digitally Enabled Patient Centric Care

ICDs and resynchronisation devices are routinely implanted in patients with heart failure for primary prevention of sudden cardiac death or to treat the condition. The addition of device features and algorithms that directly or indirectly monitor cardiac haemodynamics to assess heart failure status can provide additional benefit by treating heart failure more continuously. Established and emerging devices and sensors aimed at treating or measuring cardiac haemodynamics represent the next era of heart failure disease management. Digitally enabled models of heart failure care, based on frequent haemodynamic measurements, will increasingly involve patients in their own disease management. Software tools and services tailored to provide patients with personalised information to guide diet, activity, medications and haemodynamic management offer an unprecedented opportunity to improve patient outcomes. This will enable physicians to care for larger populations because management will be exception based, automated and no longer depend on one-to-one patient and physician interactions.

Transcatheter Interatrial Shunt Device for the Treatment of Heart Failure: Rationale and Design of the Randomized Trial to REDUCE Elevated Left Atrial Pressure in Heart Failure (REDUCE LAP-HF I)

Heart failure with preserved ejection fraction (HFpEF), a major public health problem with high morbidity and mortality rates, remains difficult to manage because of a lack of effective treatment options. Although HFpEF is a heterogeneous clinical syndrome, elevated left atrial pressure-either at rest or with exertion-is a common factor among all forms of HFpEF and one of the primary reasons for dyspnea and exercise intolerance in these patients. On the basis of clinical experience with congenital interatrial shunts in mitral stenosis, it has been hypothesized that the creation of a left-to-right interatrial shunt to decompress the left atrium (without compromising left ventricular filling or forward cardiac output) is a rational, nonpharmacological strategy for alleviating symptoms in patients with HFpEF. A novel transcatheter interatrial shunt device has been developed and evaluated in patients with HFpEF in single-arm, nonblinded clinical trials. These studies have demonstrated the safety and potential efficacy of the device. However, a randomized, placebo-controlled evaluation of the device is required to further evaluate its safety and efficacy in patients with HFpEF. In this article, we give the rationale for a therapeutic transcatheter interatrial shunt device in HFpEF, and we describe the design of REDUCE Elevated Left Atrial Pressure in Heart Failure (REDUCE LAP-HF I), the first randomized controlled trial of a device-based therapy to reduce left atrial pressure in HFpEF.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02600234.

Interatrial shunt devices for heart failure with normal ejection fraction: a technology update

Heart failure with normal ejection fraction (HeFNEF) accounts for ~50% of heart failure admissions. Its pathophysiology and diagnostic criteria are yet to be defined clearly which may hinder the search for effective treatments. The clinical hallmark of HeFNEF is exertional breathlessness, often due to an abnormal increase in left atrial pressure during exercise. Creation of an interatrial communication to offload the left atrium is a possible therapeutic approach. There are two percutaneously delivered devices currently under investigation which are discussed in this review.

Efficacy and Safety of Inter-Atrial Shunt Devices for Heart Failure With Reduced or Preserved Ejection Fraction: Early Experiences

BACKGROUND

Elevated left atrial (LA) pressure is thought to be the common final pathological way in decompensated heart failure (HF). We aimed to gather currently available clinical evidence to evaluate the feasibility of inter-atrial shunt devices in HF patients.

METHODS

We searched PubMed and Cochrane Library databases through 23rd April 23, 2016. Data were extracted by two investigators independently. We pooled outcomes of interest in Revman 5.2 (The Cochrane Collaboration, Oxford, United Kingdom).

RESULTS

A total of four records were identified in the final review, involving HF patients with reduced ejection fraction (EF) and those with preserved EF. Pooled analysis showed that pulmonary capillary wedge pressure significantly reduced after inter-atrial shunt devices implantation, with a mean difference (MD) of -3.54mmHg (95% confidence interval [CI]=-5.63 to -1.45mmHg) and low heterogeneity (I²=16%), 6-minute walk distance significantly increased, with a MD of 36.84m (95% CI=3.52 to 70.16m) and low heterogeneity (I²=0%), and Minnesota Living with Heart Failure score significantly improved (MD=-22.99 with 95% CI -44.45 to -1.52) following shunting. No evidence of worsening pulmonary hypertension was observed in these studies. No device-related deaths, thrombo-embolic or cardiac events were recorded during follow-up.

CONCLUSIONS

Current evidence suggests that inter-atrial shunting might be a potential and promising therapy for HF, regardless of the ejection fraction.

Current and Future Percutaneous Strategies for the Treatment of Acute and Chronic Heart Failure

The prevalence of heart failure (HF) has risen in parallel with improved survival in patients after a myocardial infarction and an aging population worldwide. In recent years, new percutaneous therapies have been developed to complement current established treatments for acute/decompensated and chronic HF and minimize risks. In acute presentations, the failure of medical treatment is no longer the end of the road in refractory circulatory shock; the use of mechanical circulatory support devices may be the next milestone in well-resourced health settings. Although evidence in this area is difficult to generate, research networks can facilitate the volume and quality of data needed to further augment the clinician's knowledge. Pulsatile (intra-aortic balloon pump), axial continuous (Impella), or centrifugal continuous pumps (TandemHeart; HeartMate PHP) together with percutaneously implanted extracorporeal membrane oxygenation are radically changing the prognosis of acute HF. Newer percutaneous therapies for chronic HF are based on attractive hypotheses, including left atrial decompression with shunting devices, left ventricle restoration through partitioning devices, or pressure-guided implantable therapies that may help to promptly treat decompensations. To date, only the last has been proved effective in a randomized study. Therefore, thorough research is still needed in this dynamic and promising field.

Unidirectional left-to-right interatrial shunting for treatment of patients with heart failure with reduced ejection fraction: a safety and proof-of-principle cohort study

BACKGROUND

In patients with heart failure, interventions to reduce elevated left atrial pressure improve symptoms and reduce the risk of hospital admission. We aimed to assess the safety and potential efficacy of therapeutic left-to-right interatrial shunting in patients with heart failure with reduced ejection fraction.

METHODS

We did this proof-of-principle cohort study at one centre in Canada. Patients (aged ≥18 years) with New York Heart Association (NYHA) class III chronic heart failure with reduced ejection fraction were enrolled under the Canadian special access programme. Shunt implants were done after transseptal catheterisation with transoesophageal echocardiographic guidance under general anaesthesia. Patients had clinical and echocardiography evaluations at baseline and months 1 and 3 after shunt implantation.

FINDINGS

Between Oct 10, 2013, and March 27, 2015, we enrolled ten patients. The device was successfully implanted in all patients; no device-related or procedural adverse events occurred during follow-up. Transoesophageal echocardiography at 1 month showed that all shunts were patent, with no thrombosis or migration. From baseline to 3 month follow-up, we recorded improvements in NYHA classification (from class III to class II in seven [78%] of nine patients, from class III to class I in one [11%] patient, and no change in one [11%] patient; p=0·0004); quality of life, as assessed by the Duke Activity Status Index (from a mean score of 13 [SD 6·2] to 24·8 [12·9]; p=0·016) and the Kansas City Cardiomyopathy Questionnaire (from a mean score of 44·3 [SD 9·8] to 79·1 [13·0]; p=0·0001); and 6 min walk test distance (from a mean of 244 m [SD 112] to 318 m [134]; p=0·016). Pulmonary capillary wedge pressure was reduced from a mean of 23 mm Hg (SD 5) at baseline to 17 mm Hg (8) at 3 months (p=0·035), with no changes in right atrial pressure, pulmonary arterial pressure, or pulmonary resistance. No patient was admitted to hospital for worsening heart failure. One (10%) patient was admitted to hospital with gastrointestinal bleeding at month 1; one (10%) patient died after incessant ventricular tachycardia storm, which led to terminal heart failure 2 months post-procedure.

INTERPRETATION

This first-in-man experience with an implanted left-to-right interatrial shunt demonstrates initial safety and early beneficial clinical and haemodynamic outcomes in patients with heart failure with reduced ejection fraction. Further large-scale randomised studies are warranted.

FUNDING

V-Wave.

Novel device-based interventional strategies for advanced heart failure

While heart failure is one of the leading causes of mortality and morbidity, our tools to provide ultimate treatment solutions are still limited. Recent developments in new devices are designed to fill this therapeutic gap. The scope of this review is to focus on two particular targets, namely (1) left ventricular geometric restoration and (2) atrial depressurization. (1) Reduction of the wall stress by shrinking the ventricular cavity has been traditionally attempted surgically. Recently, the Parachute device (CardioKinetix Inc., Menlo Park, CA, USA) has been introduced to restore ventricular geometry and cardiac mechanics. The intervention aims to partition distal dysfunctional segments that are non-contributory to the ventricular mechanics and forward cardiac output. (2) Diastolic heart failure is characterized by abnormal relaxation and chamber stiffness. The main therapeutic goal achieved should be the reduction of afterload and diastolic pressure load. Recently, new catheter-based approaches were proposed to reduce left atrial pressure and ventricular decompression: the InterAtrial Shunt Device (IASD™) (Corvia Medical Inc., Tewksbury, MA, USA) and the V-Wave Shunt (V-Wave Ltd, Or Akiva, Israel). Both are designed to create a controlled atrial septal defect in symptomatic patients with heart failure. While the assist devices are aimed at end-stage heart failure, emerging device-based percutaneous or minimal invasive techniques comprise a wide spectrum of innovative concepts that target ventricular remodeling, cardiac contractility or neuro-humoral modulation. The clinical adoption is in the early stages of the initial feasibility and safety studies, and clinical evidence needs to be gathered in appropriately designed clinical trials.

Advances in the pathophysiology and treatment of heart failure with preserved ejection fraction

PURPOSE OF REVIEW

With the failure of multiple trials to identify a successful therapy for heart failure with preserved ejection fraction (HFpEF), attention has shifted to defining specific phenotypes within the HFpEF spectrum in an effort to develop a targeted approach to treatment. Here we summarize the most recent studies investigating the pathophysiology and clinical features of HFpEF, and discuss recent clinical trials in the context of developing treatments that look toward the underlying cause of this disorder.

RECENT FINDINGS

Advances in basic science and clinical research have further characterized HFpEF, identifying multiple pathophysiological mechanisms that ultimately lead to exercise intolerance and volume overload. The success of small studies focused on specific subsets of the HFpEF population has promoted the concept that there may not be one treatment strategy that can universally be applied to HFpEF.

SUMMARY

HFpEF is associated with significant morbidity and mortality and accounts for approximately half of patients with chronic heart failure. HFpEF is a complex disease, encompassing a diverse cohort of patients and marked by the presence of multiple etiological mechanisms. The failure to develop successful therapies for the management of HFpEF may be because of inadequate standardization of the HFpEF diagnosis, overly broad inclusion criteria and inadequate differentiation of disease subtypes. Given the heterogeneity among patients with HFpEF, much of the current research is focused on understanding of pathophysiology and identifying disease phenotypes that may respond to a targeted treatment approach. Several newer approaches, including neprilysin inhibition and device therapy, offer promise for a new era of HFpEF treatment.

Innovative devices for advanced heart failure: exploring the current state and future direction of device therapies

PURPOSE OF REVIEW

Despite improvements in medical and device therapies for the treatment of heart failure, the incidence and prevalence of heart failure continue to increase. Given the relative stagnation in new pharmacologic therapies, considerable attention has been given in recent years to device therapies to supplement care in patients with advanced heart failure. Recent successful clinical trial results with an angiotensin-neprilysin inhibitor are not expected to change this situation significantly; the drug has been shown to delay, not eliminate, the progression of heart failure. This review focuses on the technologies that are currently in development for the treatment of advanced heart failure.

RECENT FINDINGS

Novel devices that involve electrical, neurohormonal or structural remodeling of the heart that can be inserted either percutaneously or with a minimally invasive surgery are currently at various stages of clinical development. All, however, have shown promising clinical results in preclinical and early clinical studies.

SUMMARY

Novel device therapies for advanced heart failure continue to show promising clinical results. Randomized controlled trials are still needed to better evaluate their efficacy. Nevertheless, it can be anticipated that at least several of these devices will be among the armamentarium of treatment options for advanced heart failure in the future.