Long term safety and outcomes after atrial shunting for heart failure with preserved or mildly reduced ejection fraction: 5-year and 3-year follow-up in the REDUCE LAP-HF I and II trials

BACKGROUND

There is a little evidence regarding long-term safety and efficacy for atrial shunt devices in heart failure (HF).

METHODS

The REDUCE LAP-HF I (n = 44) and II (n = 621) trials (RCT-I and -II) were multicenter, randomized, sham-controlled trials of patients with HF and ejection fraction >40%. Outcome data were analyzed from RCT-I, a mechanistic trial with 5-year follow-up, and RCT-II, a pivotal trial identifying a responder group (n = 313) defined by exercise PVR <1.74 WU and no cardiac rhythm management device with 3-year follow-up.

RESULTS

At 5 years in RCT I, there were no differences in cardiovascular (CV) mortality, HF events, embolic stroke, or new-onset atrial fibrillation between groups. After 3 years in RCT II, there was no difference in the primary outcome (hierarchical composite of CV mortality, stroke, HF events, and KCCQ) between shunt and sham in the overall trial. Compared to sham, those with responder characteristics in RCT-II had a better outcome with shunt (win ratio 1.6 [95% CI 1.2-2.2], P = .006; 44% reduction in HF events [shunt 9 vs. control 16 per 100 patient-years], P = .005; and greater improvement in KCCQ overall summary score [+17.9 ± 20.0 vs. +7.6 ± 20.4], P < .001), while nonresponders had significantly more HF events. Shunt treatment at 3 years was associated with a higher rate of ischemic stroke (3.2% vs. 0%, 95% CI 2%-6.1%, P = .032) and lower incidence of worsening kidney dysfunction (10.7% vs. 19.3%, P = .041).

CONCLUSIONS

With up to 5 years of follow up, adverse events were low in patients receiving atrial shunts. In the responder group, atrial shunt treatment was associated with a significantly lower HF event rate and improved KCCQ compared to sham through 3 years of follow-up.

CLINICALTRIALS

GOV REGISTRATION

NCT02600234, NCT03088033.

Complete atrioventricular block after atrial flow regulator implantation in a 5 kg infant

The atrial flow regulator is a new self-expandable double-disc fenestrated device providing a calibrated inter-atrial communication. Paediatric reports are scarce. We herein describe a case of complete atrioventricular block complicating the exemption use of an atrial flow regulator in a 5-kg infant with transposition of the great arteries, ventricular septal defect, and right ventricular outflow tract obstruction.

Left Atrial Hemodynamics and Clinical Utility in Heart Failure

Comprehensive knowledge of the left atrium (LA) and its pathophysiology has emerged as an important clinical and research focus in the heart failure (HF) arena. Although studies on HF focusing on investigating left ventricular remodeling are numerous, those on atrial structural and functional changes have received comparatively less attention. Studies on LA remodeling have recently received increasing attention, and LA pressure (LAP) has become a novel target for advanced monitoring and is a potential therapeutic approach for treating HF. Various devices specifically designed for the direct measurement of LAP have been developed to optimize HF treatment by reducing LAP. This review focuses on LA hemodynamic monitoring and effective LAP decompression.

[Pulmonary hypertension in adults with congenital heart disease in light of the 2022-ESC-PAH guidelines - Part II: Supportive therapy, special situations (pregnancy, contraception, non-cardiac surgery), targeted pharmacotherapy, organ transplantation, special management (shunt lesions, left ventricular disorders, univentricular hearts), interventions, intensive care, follow-up, future perspectives]

The number of adults with congenital heart defects (CHD) is steadily rising and amounts to approximately 360,000 in Germany. CHD is often associated with pulmonary hypertension (PH), which may develop early in untreated CHD. Despite timely treatment of CHD, PH not infrequently persists or recurs in older age and is associated with significant morbidity and mortality.The revised European Society of Cardiology/European Respiratory Society 2022 guidelines for the diagnosis and treatment of PH represent a significant contribution to the optimized care of those affected. However, the topic of "adults with congenital heart disease" is addressed only relatively superficial in these guidelines. Therefore, in the present article, this topic is commented in detail from the perspective of congenital cardiology.

The Therapy and Management of Heart Failure with Preserved Ejection Fraction: New Insights on Treatment

Heart failure with preserved ejection fraction (HFpEF) is a clinical syndrome characterised by the presence of diastolic dysfunction and elevated left ventricular filling pressure, in the setting of a left ventricular ejection fraction of at least 50%. Despite the epidemiological prevalence of HFpEF, a prompt diagnosis is challenging and many uncertainties exist. HFpEF is characterised by different phenotypes driven by various cardiac and non-cardiac comorbidities. This is probably the reason why several HFpEF clinical trials in the past did not reach strong outcomes to recommend a single therapy for this syndrome; however, this paradigm has recently changed, and the unmet clinical need for HFpEF treatment found a proper response as a result of a new class of drug, the sodium-glucose cotransporter 2 inhibitors, which beneficially act through the whole spectrum of left ventricular ejection fraction. The aim of this review was to focus on the therapeutic target of HFpEF, the role of new drugs and the potential role of new devices to manage the syndrome.

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.

Medical Management and Device-Based Therapies in Chronic Heart Failure

Heart failure (HF) remains a major cause of morbidity and mortality worldwide. Major advancements in optimal guideline-directed medical therapy, including novel pharmacological agents, are now available for the treatment of chronic HF including HF with reduced ejection fraction and HF with preserved ejection fraction. Despite these efforts, there are several limitations of medical therapy including but not limited to: delays in implementation and/or initiation; inability to achieve target dosing; tolerability; adherence; and recurrent and chronic costs of care. A significant proportion of patients remain symptomatic with poor HF-related outcomes including rehospitalization, progression of disease, and mortality. Driven by these unmet clinical needs, there has been a significant growth of innovative device-based interventions across all HF phenotypes over the past several decades. This state-of-the-art review will summarize the current landscape of guideline-directed medical therapy for chronic HF, discuss its limitations including barriers to implementation, and review device-based therapies which have established efficacy or demonstrated promise in the management of chronic HF.

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.

Atrial Shunt Therapy for Heart Failure: An Update

Transcatheter atrial shunt therapies, designed to dynamically lower left atrial (LA) pressure by shunting blood into the larger reservoir of the right atrium and central veins, have been developed as a novel treatment for heart failure (HF) over the past 10+ years. Several atrial shunt devices and procedures are currently in development with several pivotal randomized clinical trials (RCT) underway; however, only 2 sham-controlled RCT (both with the Atrial Shunt Device [Corvia Medical] in HF with EF ≥ 40%) have been reported thus far; a mechanistic RCT (n = 44) that demonstrated a reduction in exercise LA pressure at 1 month and a pivotal RCT (n = 626) that was neutral with no difference in outcomes or health status between shunt and sham groups. Subsequent analyses of the single completed pivotal RCT found that peak exercise pulmonary vascular resistance <1.74 WU plus the absence of a cardiac rhythm management device identified a responder group that benefited from LA unloading with atrial shunt implantation, a finding that is currently being confirmed in a follow-up RCT. Here we provide a comprehensive review of the field of atrial shunt therapeutics with a description of the following: (1) current HF treatment; (2) rationale and history of atrial shunt development; (3) design of and accumulated evidence for the various atrial shunt devices and procedures under investigation; (4) unanswered questions in the field; and (5) future considerations. Atrial shunts represent a potential innovative therapeutic for HF but the optimal design/approach and phenotype of HF most likely to benefit are yet to be determined.

Hybrid approach for end-stage heart failure treatment in a 6-month-old baby

A 6-month-old baby girl, with a history of 2 months of intensive care management and two episodes of cardiac arrest, was transferred from another European country to initiate the "Giessen approach" for end-stage heart failure in children. At the admission, left ventricular ejection fraction was 20%. Severe mitral valve regurgitation and severe left atrial dilatation were present. Right ventricular function was preserved, and tricuspid valve regurgitation was mild. As a result, the patient underwent surgical pulmonary artery banding. Additionally, unloading of the left atrium was achieved by implanting an 8 mm atrial flow regulator device through a hybrid per-atrial approach. Two months after the procedure, the patient was progressively weaned from the inotropes and transferred to the ward.

Predicted impact of atrial flow regulator on survival in heart failure with reduced and preserved ejection fraction

AIMS

We aim to assess the theoretical impact of the atrial flow regulator (AFR) on survival in heart failure.

METHODS AND RESULTS

The prospective, multicentre, open-label, non-randomised PRELIEVE study (NCT03030274) assessed the safety and efficacy of the Occlutech AFR device in patients with symptomatic heart failure with reduced ejection fraction (HFrEF) (left ventricular ejection fraction (LVEF) ≥ 15% and <40%) or heart failure with preserved ejection fraction (HFpEF) (LVEF ≥40% and <70%) and elevated PCWP (≥15 mmHg at rest or ≥25 mmHg during exercise). In this analysis, after the first 60 patients completed 12 months of follow-up, the theoretical impact of AFR implantation on survival was assessed by comparing the observed mortality rate with the median predicted probability for one-year mortality. Each subject's risk of mortality was predicted from individual baseline data using the Meta-Analysis Global Group in Chronic HF (MAGGIC) prognostic model. A total of 87 patients (46% female, median age 69 years [IQR 62-74]) had undergone successful device implantation for the treatment of HFrEF (53%) and HFpEF (47%). Sixty patients had a complete 12 month follow-up. The median follow-up was 351 days (interquartile range [IQR] 202-370). Six (7%) patients died during follow-up (8.6 deaths per 100 patient-years; 95% confidence interval [CI] 2.7 to 15.5), all of which had HFrEF. The median predicted mortality rate for the overall study population was 12.2 deaths per 100 patient-years (95% CI 10.2 to 14.7). While the observed mortality rate (0 deaths per 100 patient-years) was significantly lower than the median predicted mortality rate (9.3 deaths per 100 patient-years; 95% CI 8.4 to 11.1) in patients with HFpEF (-9.3 deaths per 100 patient-years; 95% CI -11.1 to -8.4), there was no difference in patients with HFrEF (-3.6 deaths per 100 patient-years; 95% CI -9.5 to 3.0). Four deaths were HF-related deaths (5.7 HF-related deaths per 100 patient-years; 95% CI 1.4 to 11.9; 10.8 HF-related deaths per 100 patient-years; 95% CI 2.5 to 23.1 in the HFrEF subgroup).

CONCLUSIONS

In patients with HFpEF, the mortality rate following AFR implantation was lower than the predicted mortality rate. Dedicated randomised, controlled trials are needed - and currently ongoing - to investigate whether the AFR improves mortality.

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.

Transcatheter interventions for heart failure

Despite significant advances in the medical management of patients living with heart failure, there continues to be significant morbidity and mortality associated with the condition. There is a growing need for research and development of additional modalities to fill the management and treatment gaps, reduce hospitalisations and improve the quality of life for patients living with heart failure. In the last decade, there has been a rapid rise in the use of non-valvular catheter-based therapies for the management of chronic heart failure to complement existing guideline-directed management. They target well-defined mechanistic and pathophysiological processes critical to the progression of heart failure including left ventricular remodelling, neurohumoral activation, and congestion. In this review, we will explore the physiology, rationale, and current stages of the clinical development of the existing procedures.

Feasibility, safety, and efficacy of Atrial Flow Regulator in children under 10 kg

INTRODUCTION

The Atrial Flow Regulator (AFR) is a new self-expandable percutaneous-delivered fenestrated device providing an interatrial shunt. Its use in pediatric population has been reported in failing Fontan, pulmonary hypertension, or in patients with cardiomyopathy and venoarterial extracorporeal membrane oxygenator (ECMO) support. Its use in small children under 10 kg has not been reported.

METHODS

We report the initial single center experience of the AFR implantation in children below 10 kg.

RESULTS

Four children underwent AFR implantation. Patients' age and weight ranged between 9 and 22 months and 5-8.7 kgs. Indications were to unload the left atrium during ECMO support for end-stage cardiomyopathy and to enlarge a restrictive interatrial shunt in two other patients with complex congenital heart diseases. Devices implanted were AFR-6 and AFR-8. Delivery sheaths used via venous femoral access were undersized and ranged from 9 to 11 Fr. Devices were successfully implanted and provided unrestrictive interatrial shunt in all cases. One child developed a nonocclusive thrombus in the inferior vena cava which resolved within 1 month. Clinical improvement and femoral vein patency were observed in all cases.

CONCLUSION

AFR implantation is feasible in selected children under 10 kg. The AFR can be safely deployed through sheaths that are 1-2 Fr smaller than the recommended manufacturer size. More studies are needed to confirm safety and efficacy of the device in selected pediatric patients.

Biventricular longitudinal strain as a predictor of functional improvement after D-shant device implantation in patients with heart failure

Background

The creation of an atrial shunt is a novel approach for the management of heart failure (HF), and there is a need for advanced methods for detection of cardiac function response to an interatrial shunt device. Ventricular longitudinal strain is a more sensitive marker of cardiac function than conventional echocardiographic parameters, but data on the value of longitudinal strain as a predictor of improvement in cardiac function after implantation of an interatrial shunt device are scarce. We aimed to investigate the exploratory efficacy of the D-Shant device for interatrial shunting in treating heart failure with reduced ejection fraction (HFrEF) and heart failure with preserved ejection fraction (HFpEF), and to explore the predictive value of biventricular longitudinal strain for functional improvement in such patients.

Methods

A total of 34 patients were enrolled (25 with HFrEF and 9 with HFpEF). All patients underwent conventional echocardiography and two-dimensional speckle tracking echocardiogram (2D-STE) at baseline and 6 months after implantation of a D-Shant device (WeiKe Medical Inc., WuHan, CN). Left ventricular global longitudinal strain (LVGLS) and right ventricular free wall longitudinal strain (RVFWLS) were evaluated by 2D-STE.

Results

The D-Shant device was successfully implanted in all cases without periprocedural mortality. At 6-month follow-up, an improvement in New York Heart Association (NYHA) functional class was observed in 20 of 28 patients with HF. Compared with baseline, patients with HFrEF showed significant reduced left atrial volume index (LAVI) and increased right atrial (RA) dimensions, as well as improved LVGLS and RVFWLS, at 6-month follow-up. Despite reduction in LAVI and increase in RA dimensions, improvements in biventricular longitudinal strain did not occur in HFpEF patients. Multivariate logistic regression demonstrated that LVGLS [odds ratio (OR): 5.930; 95% CI: 1.463-24.038; P = 0.013] and RVFWLS (OR: 4.852; 95% CI: 1.372-17.159; P = 0.014) were predictive of improvement in NYHA functional class after D-Shant device implantation.

Conclusion

Improvements in clinical and functional status are observed in patients with HF 6 months after implantation of a D-Shant device. Preoperative biventricular longitudinal strain is predictive of improvement in NYHA functional class and may be helpful to identify patients who will experience better outcomes following implantation of an interatrial shunt device.

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.

Update on Atrial Shunt Therapy for Treatment of Heart Failure

Heart failure with preserved ejection fraction is associated with elevated left atrial pressure during exercise. Sodium-glucose cotransporter-2 inhibitors have demonstrated the evidence of benefit in heart failure with preserved ejection fraction, but even with this treatment, heart failure hospitalizations remain high, and improvements in quality of life scores are modest. Thus, there is growing interest in nonpharmacological methods of limiting the rise in left atrial pressure during exertion. Creation of an interatrial shunt (IAS) may unload the left heart during exercise. Multiple implant or nonimplant IAS procedures are under investigation. Implantation of the most studied device results in 3 to 5 mm Hg decreases in pulmonary capillary wedge pressure during exercise, no increase in incidence of stroke, stable increases in Qp/Qs (1.2-1.3), and mild right heart enlargement without change in function out to at least a year after treatment. The findings from the first large randomized controlled trial of an atrial shunt have recently been published. For the population as a whole, implantation of the atrial shunt device appeared to be safe but did not provide clinical benefit. However, prespecified and post-hoc analyses have demonstrated that men, patients with larger right atrial volumes, and those with pulmonary artery systolic pressure >70 mm Hg at 20 W exercise had worse outcomes with IAS therapy, whereas those with peak exercise pulmonary vascular resistance <1.74 Wood units and absence of a pacemaker represented a potential responder group. Here, we summarize the results of the published data and the current IAS therapies under investigation. We also highlight unanswered questions in this field of inquiry.

Interventionelle Behandlungsverfahren der pulmonalen Hypertension im Kindesalter

Die pulmonale Hypertension (PH) ist eine progressive Gefäßerkrankung und führt über eine Widerstands- und/oder Druckerhöhung im kleinen Kreislauf zu einem fortschreitenden Rechtsherzversagen. Auch wenn mithilfe aktueller medikamentöser Therapien eine deutliche Verbesserung der Lebensqualität und des Überlebens der Betroffenen erreicht werden konnte, bleibt die PH eine zumeist nichtheilbare Erkrankung, die im fortgeschrittenen Stadium eine Lungentransplantation notwendig macht. Interventionelle Verfahren, wie die Anlage eines interatrialen Shunts (z. B. durch atriale Septostomie oder den Atrial Flow Regulator) oder eines Reversed Potts Shunt, verbessern die RV-Funktion und die ventrikuläre Interaktion durch Schaffung einer prä- oder posttrikuspidalen „Eisenmenger-Physiologie“ und stellen eine Überbrückung oder sogar Alternative zur Lungentransplantation dar. Bei Patienten mit segmentaler PH oder chronisch thrombembolischer pulmonaler Hypertension (CTEPH) stellt die Ballonangioplastie eine bereits etablierte Intervention zur Verbesserung der pulmonalen Perfusion und damit rechtsventrikulären (RV-)Funktion dar. Dagegen ist die pulmonalarterielle Denervation ein neuartiges Verfahren, mit dem Ziel, die neurohumorale Dysregulation bei PH positiv zu beeinflussen. Der individuelle Einsatz solcher Interventionen, additiv zu den bereits etablierten medikamentösen Therapien, erweitert die Behandlungsmöglichkeiten und kann die Prognose betroffener Patienten noch weiter verbessern.

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.

Restructuring the Heart From Failure to Success: Role of Structural Interventions in the Realm of Heart Failure

Heart failure through the spectrum of reduced (HFrEF), mid-range (or mildly reduced or HFmEF), and preserved ejection fraction (HFpEF), continues to plague patients' quality of life through recurrent admissions and high mortality rates. Despite tremendous innovation in medical therapy, patients continue to experience refractory congestive symptoms due to adverse left ventricular remodeling, significant functional mitral regurgitation (FMR), and right-sided failure symptoms due to significant functional tricuspid regurgitation (FTR). As most of these patients are surgically challenging for open cardiac surgery, the past decade has seen the development and evolution of different percutaneous structural interventions targeted at improving FMR and FTR. There is renewed interest in the sphere of left ventricular restorative devices to effect reverse remodeling and thereby improve effective stroke volume and patient outcomes. For patients suffering from HFpEF, there is still a paucity of disease-modifying effective medical therapies, and these patients continue to have recurrent heart failure exacerbations due to impaired left ventricular relaxation and high filling pressures. Structural therapies involving the implantation of inter-atrial shunt devices to decrease left atrial pressure and the development of implantable devices in the pulmonary artery for real-time hemodynamic monitoring would help redefine treatment and outcomes for patients with HFpEF. Lastly, there is pre-clinical data supportive of soft robotic cardiac sleeves that serve to improve cardiac function, can assist contraction as well as relaxation of the heart, and have the potential to be customized for each patient. In this review, we focus on the role of structural interventions in heart failure as it stands in current clinical practice, evaluate the evidence amassed so far, and review promising structural therapies that may transform the future of heart failure management.

A Glimpse Into the Future of Transcatheter Interventional Heart Failure Therapies

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HF affects millions of patients every year, adding a significant financial burden to global health care systems.

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This review discusses the role of novel transcatheter-based therapies for the management of HF.

•

Ongoing clinical trials will provide answers on the potential clinical benefits of these technologies in HF outcomes.

Chronic heart failure is one of the most debilitating chronic conditions affecting millions of people and adding a significant financial burden to health care systems worldwide. Despite the significant therapeutic advances achieved over the last decade, morbidity and mortality remain high. Multiple catheter-based interventional therapies targeting different physiological and anatomical targets are already under different stages of clinical investigation. The present paper provides a technical overview of the most relevant catheter-based interventional therapies under clinical investigation.

Transcatheter Implantation of Interatrial Shunt Devices to Lower Left Atrial Pressure in Heart Failure

Patients with heart failure with preserved ejection fraction (HFpEF) constitutes a considerable sized population like that of subjects with heart failure with reduced ejection fraction. The symptoms include exercise induced dyspnoea and fatigue besides an increased mortality rate when compared to the general population. There is limited evidence of benefit from pharmacological therapy. A main pathophysiological mechanism is a left ventricular filling pressure that might be near to normal during resting conditions but increases during exercise leading to pulmonary congestion. Based on observations like the apparent lesser symptomatology in patients with combined mitral valve stenosis and atrial septal defect (Lutembacher syndrome) when compared to patients with isolated mitral valve stenosis, several Inter-Atrial Shunt Devices (IASD) have been developed with the intent to unload the pressure in the left atrium by creating a shunt into the right atrium. Smaller studies have found that the IASDs reduce the left ventricular filling pressure during exercise and increase the functional status of patients both subjectively and objectively with reported low rates of complications. These devices are undergoing further investigations and might prove to be a new paradigm in the treatment of patients with HFpEF.

The impact of atrial flow regulator implantation on hemodynamic parameters in patients with heart failure

Background    Left atrial decompression has emerged a new option to treat patients with heart failure and dyspnea at rest or during exercise. Here we report the impact of atrial flow regulator (AFR) implantation on hemodynamic parameters in patients at our center with heart failure and with reduced (HFrEF) or with preserved left ventricular ejection fraction (HFpEF).Material and methods    The PRELIEVE trial is designed to assess the safety and efficacy of the AFR in patients with HFrEF or HFpEF. Patients with left ventricular end-diastolic pressure ≥15 mmHg at rest or ≥25 mmHg during exercise and with an ejection fraction ≥15 % were enrolled. Echocardiographic data, 6‑min walking distance, Kansas City Cardiomyopathy Questionnaire, and brain natriuretic peptide levels were assessed pre- and post-AFR implantation and at 3 mos. Invasive hemodynamic assessments were also performed pre- and post-AFR implantation and at 3 mos.Results    27 (69.2 %) patients with HFrEF and 12 (30.8 %) patients with HFpEF at our center were enrolled in this study. A significant decrease was observed in pulmonary arterial wedge pressure regardless of EF (p=0.007 for HFrEF and p=0.03 for HFpEF). No significant difference of mean pulmonary arterial pressure, right arterial pressure and cardiac output (CO) existed at 3 months compared with pre-implantation baseline values.Conclusion    AFR implantation led to decrease in left ventricle filling pressure without the deleterious impact on CO and right heart function regardless of ejection fraction.

Feasibility and efficacy of transcatheter interatrial shunt devices for chronic heart failure: a systematic review and meta-analysis

AIMS

To assess the feasibility and efficacy of interatrial shunt devices (IASD) for the treatment of chronic heart failure (CHF).

METHODS AND RESULTS

MEDLINE and the Cochrane Central Register of Controlled Trials from inception until April 2021 were searched for prospective studies investigating dedicated transcatheter IASD for the treatment of CHF. Standardised mean differences were calculated for the within-group changes before and after implantation of the IASD. The pre-defined primary outcome was change in 6-min walking distance (6MWD) from baseline to 12 months. Other outcomes were change in New York Heart Association class, health-related quality of life (HRQoL), echocardiographic and haemodynamic data, device performance and safety. Subgroup analyses were crude univariable meta-regression analyses. Six studies (five single-arm open-label studies, one sham-controlled trial) were included. In these, 226 patients underwent IASD implantation using four different devices. From baseline to 12 months, 6MWD increased by 28.1 m [95% confidence interval (CI) 10.9-45.3] with no evidence for a difference between devices (P for interaction = 0.66) and patients with left ventricular ejection fraction (LVEF) >40% or ≤40% (P for interaction = 0.21). At 12 months, HRQoL improved by 17.7 points (95% CI 10.8-24.6) and pulmonary capillary wedge pressure (PCWP) decreased by 2.0 mmHg (95% CI -3.6 to -0.4). There were no changes in LVEF or N-terminal pro brain natriuretic peptide during follow-up. Shunt patency ranged from 50% for the first-generation v-Wave to 100% for the Corvia IASD II and the second-generation v-Wave system, respectively. The summary risk of serious adverse device-related effects was 8% (95% CI 1-20) at 12 months.

CONCLUSIONS

Interatrial shunt device implantation in CHF is feasible and associates with improved submaximal exercise capacity (measured by 6MWD) and HRQoL, and reductions in PCWP.

Impact of atrial flow regulator (AFR) implantation on 12-month mortality in heart failure : Insights from a single site in the PRELIEVE study

BACKGROUND

Implantation of the atrial flow regulator (AFR) to create an interatrial left-to-right shunt has been shown to be safe and feasible to reduce intracardiac filling pressures in patients with heart failure (HF).

OBJECTIVES

We aimed to assess the effect of AFR implantation on 12-month mortality and hospitalization rates in patients with reduced (HFrEF) or preserved HF (HFpEF).

METHODS

One-year follow-up data from 34 subjects enrolled at a single PRELIEVE center were analyzed. The 12-month predicted mortality was calculated using the Meta-Analysis Global Group in Chronic Heart Failure (MAGGIC) risk score. Patients were divided into two groups, according to their history of hospitalizations for HF.

RESULTS

Study data of 34 patients (HFrEF: 24 [70.6%]; HFpEF: 10 [29.4%]) were assessed. Median follow-up duration was 355 days. In total, 14 (41.2%) patients were hospitalized during the follow-up period and 6 (17.6%) of these patients were hospitalization for HF (HHF). A total of 24 hospitalizations occurred in this period and 8 (33%) hospitalizations were for HHF. The median baseline MAGGIC score was 23 and the median predicted mortality was 13.4/100 patient years. Observed mortality was 3.1/100 patient years. The observed survival (97%) was 10.3% (95% confidence interval 3.6-17.5%, p = 0.004) better than the predicted survival (86.6%).

CONCLUSION

Our results suggest that AFR implantation has favorable effects on mortality in patients with heart failure, regardless of ejection fraction. Furthermore, compared to baseline, left ventricular filling pressure (assessed by echocardiography) decreased significantly without right side volume overload at the 1‑year follow-up.

The Atrial Flow Regulator: A Novel Device for Left Ventricular Unloading in Patients Receiving Venoarterial Extracorporeal Membrane Oxygenation Support?

Severe pulmonary edema, secondary to left ventricular afterload increment, is a common problem occurring in patients receiving venoarterial extracorporeal membrane oxygenation. No consensus is currently available for its management, but several devices/procedures have been described, including an Impella device (Abiomed), balloon atrial septostomy, intraaortic balloon counterpulsation, or an additional venous cannula, as possible adjuncts. We report the feasibility and efficacy of the atrial flow regulator device (Occlutech) for left ventricular unloading in a 58-year-old patient receiving extracorporeal membrane oxygenation. However, the benefits of this device relative to simple balloon atrial septostomy need to be further investigated.

Interventional and Surgical Treatments for Pulmonary Arterial Hypertension

Despite significant advancements in pharmacological treatment, interventional and surgical options are still viable treatments for patients with pulmonary arterial hypertension (PAH), particularly idiopathic PAH. Herein, we review the interventional and surgical treatments for PAH. Atrial septostomy and the Potts shunt can be useful bridging tools for lung transplantation (Ltx), which remains the final surgical treatment among patients who are refractory to any other kind of therapy. Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) remains the ultimate bridging therapy for patients with severe PAH. More importantly, VA-ECMO plays a crucial role during Ltx and provides necessary left ventricular conditioning during the initial postoperative period. Pulmonary denervation may potentially be a new way to ensure better transplant-free survival among patients with the aforementioned disease. However, high-quality randomized controlled trials are needed. As established, obtaining the Eisenmenger physiology among patients with severe pulmonary hypertension by creating artificial defects is associated with improved survival. However, right-to-left shunting may be harmful after Ltx. Closure of the artificially created defects may carry some risk associated with cardiac surgery, especially among patients with Potts shunts. In conclusion, PAH requires an interdisciplinary approach using pharmacological, interventional, and surgical modalities.

One-year results of the first-in-man study investigating the Atrial Flow Regulator for left atrial shunting in symptomatic heart failure patients: the PRELIEVE study

AIMS

Attenuating exercise-induced elevated left atrial pressure with an atrial shunt device is under clinical investigation for treatment of symptomatic heart failure (HF).

METHODS AND RESULTS

PRELIEVE was a prospective, non-randomised, multicentre, first-in-man study in symptomatic HF patients with reduced (HFrEF) or preserved (HFpEF) ejection fraction and pulmonary capillary wedge pressure (PCWP) ≥15 mmHg at rest or ≥25 mmHg during exercise. Here, we provide follow-up data up to 1 year after implantation of the Atrial Flow Regulator (AFR) device. The AFR was successfully implanted in 53 patients (HFrEF n = 24 and HFpEF n = 29). Two patients were not enrolled due to an unsuccessful transseptal puncture. There was one device embolisation into the left atrium, which required surgical removal. One patient experienced a serious procedure-related adverse event (post-procedural bleeding and syncope). All patients with sufficient echocardiography readout confirmed device patency with left-right shunt both at 3 (n = 47/51, 92%) and 12 (n = 45/49, 92%) months. At 3 months, rest PCWP decreased by 5 (-12, 0) mmHg (P = 0.0003, median Q1, Q3). No patient developed a stroke, worsening of right heart function or significant increase of pulmonary artery pressure. Six (6/53, 11%) patients were hospitalised for worsening of HF and three (3/53, 6%) patients died. We observed improvements in New York Heart Association functional class, 6-min walking distance and quality of life (Kansas City Cardiomyopathy Questionnaire) in certain patients.

CONCLUSIONS

Implantation of the AFR device in HF patients was feasible. No shunt occlusion, stroke or new right HF was observed during the 1-year follow-up, with clinical improvements in certain patients.

Heart failure and atrial fibrillation in patients with an interatrial shunt

OBJECTIVE

Congenital interatrial shunt can unload the left atrium (LA) and may lower the risk of new-onset heart failure (HF) or atrial fibrillation (AF). We evaluated the risk of new-onset HF or AF in patients with and without interatrial shunt.

METHODS

We enrolled 2660 consecutive patients with acute stroke or transient ischemic attack (TIA) who underwent transesophageal echocardiography at Seoul National University Bundang Hospital from January 1, 2006 to December 31, 2018. The primary outcomes were 10-year new-onset HF, new-onset AF, and new-onset HF or AF composite.

RESULTS

Overall, 466 (17.5%) patients with an interatrial shunt had smaller E velocity (0.66 ± 0.21 vs. 0.69 ± 0.22 m/s, P = 0.037) and smaller E/e' (9.1 ± 4.0 vs. 10.0 ± 5.0, P = 0.001) than 2194 (82.5%) patients without an interatrial shunt. The 10-year incidence of AF, HF, and AF or HF composite was lower in patients with an interatrial shunt (10-year AF, 11.2 vs. 17.8%, P < 0.001; 10-year HF, 6.2 vs. 10.4%, P = 0.005; 10-year AF or HF composite, 16.5 vs. 23.4%, P = 0.001). In multivariable analysis, the presence of an interatrial shunt was associated with a 38% (HR 0.62, 95% CI 0.40-0.96), 40% (HR 0.60; 95% CI 0.39-0.93), and 26% (HR 0.74; 95% CI 0.57-0.96) reduced risk for new-onset HF, AF, and new-onset HF or AF composite, respectively.

CONCLUSION

In patients with interatrial shunt, the risk of AF and HF was lower. Interatrial shunt may be beneficial, and the closure of an interatrial shunt should be performed only in carefully selected patients. An interatrial shunt can unload the left atrium. In patients with stroke or TIA, the presence of an interatrial shunt was associated with a reduced risk for new-onset HF and AF. AF atrial fibrillation, HF heart failure, HR hazard ratio, LA left atrium.

Implantation of an Atrial Flow Regulator in a Child on Venoarterial Extracorporeal Membrane Oxygenator as a Bridge to Heart Transplant: A Case Report

BACKGROUND

Balloon dilation and stenting of the atrial septum are techniques used to unload left heart cavities in acute or end-stage heart failure in children. However, they carry significant risks such as tamponade or device embolization.

CASE PRESENTATION

We report the first case of a child with an end-stage mitochondrial cardiomyopathy on a venoarterial extracorporeal membrane oxygenator as a bridge to heart transplant where an atrial flow regulator device has been implanted.

CONCLUSIONS

This case illustrates the feasibility and safety of atrial flow regulator implantation in this setting. This procedure allowed to wean inotropic support while awaiting heart transplantation.

Transseptal puncture for ablation of atrial fibrillation in a patient with an implanted atrial flow regulator: a case report

Background

Atrial flow regulator (AFR) (Occlutech, Helsingborg, Sweden) are self-expanding, circular devices. A flexible waist in the centre connects the two discs and has a centrally located shunt.

Case summary

We report a case of an 80-year-old woman undergoing a repeat left atrial ablation for persistent atrial fibrillation with an implanted AFR. The AFR was implanted 1 year prior to the procedure for heart failure with preserved ejection fraction as part of the AFR-PRELIEVE trial. A single, fluoroscopy-guided, transseptal puncture was performed infero-posterior to the device, allowing the positioning of the mapping (LASSO^® 20 mm, Biosense Webster, Irvine, CA, USA) and ablation (Thermocool Smarttouch SF, CARTO^®, Biosense Webster, Irvine, CA, USA) catheter in the left atrium. Three-dimensional mapping (CARTO^®, Biosense Webster, Irvine, CA, USA) and left atrial ablation were successfully performed. After the procedure, fluoroscopy and transthoracic echocardiography showed an unchanged device position.

Discussion

To our knowledge, this is the first case report of a transseptal puncture in a patient with an implanted AFR. Transseptal puncture in patients with an implanted AFR seems to be safe and feasible. With device diameters of 21–23 mm and based on previous studies on similar devices, transseptal puncture should be possible in most patients, as opposed to puncture through the device.

Transseptal access through atrial flow regulator device during ventricular tachycardia ablation

Novel interventional therapies for heart failure patients are emerging like atrial flow regulator (AFR). Our case showed that endocardial ventricular tachycardia (VT) ablation could be performed safely by passing through the AFR device lumen without additional transseptal puncture in these patients.

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.