Latent Pulmonary Vascular Disease May Alter the Response to Therapeutic Atrial Shunt Device in Heart Failure

Invasive haemodynamic assessment in heart failure with preserved ejection fraction

Despite the increasing prevalence and substantial burden of heart failure with preserved ejection fraction (HFpEF), which constitutes up to 50% of all heart failure cases, significant challenges persist in its diagnostic and therapeutic strategies. These difficulties arise primarily from the heterogeneous nature of the condition, the presence of various comorbidities and a wide range of phenotypic variations. Considering these challenges, current international guidelines endorse the utilization of invasive haemodynamic assessments, including resting and exercise haemodynamics, as the gold standard for enhancing diagnostic accuracy in cases where traditional diagnostic methods yield inconclusive results. These assessments are crucial not only for confirming the diagnosis but also for delineating the complex underlying pathophysiology, enabling the development of personalized treatment strategies, and facilitating the precise classification of HFpEF phenotypes. In this review, we summarize the haemodynamic changes observed in patients with HFpEF, comparing resting and exercise-induced parameters to those of normal subjects. Additionally, we discuss the current role of invasive haemodynamics in HFpEF assessment and highlight its utility beyond diagnosis, such as identifying HFpEF comorbidities, guiding phenotype-based personalized therapies and characterizing prognostication. Finally, we address the challenges associated with utilizing invasive haemodynamics and propose future directions, focusing on integrating these assessments into routine HFpEF care.

Therapeutic left-to-right shunting in heart failure

Heart failure with reduced or preserved ejection fraction is associated with elevated left atrial pressure at rest due to fluid overload or during exercise, leading to pulmonary venous congestion. Even with available treatments, heart failure hospitalizations remain high, and improvements in quality-of-life scores and functional capacity are modest. Thus, there is growing interest in non-pharmacological methods to decompress the left atrium and improve heart failure symptoms and outcomes. Left-to-right shunts have emerged as a potential therapeutic option to reduce left atrial hypertension, improve quality of life, and impact long-term outcomes. This nascent field carries both potential therapeutic promise and many unanswered questions. Recent data have questioned whether the effects of this therapy vary based on the left ventricular ejection fraction, pulmonary vascular resistance, and/or right ventricular structure and function. This review discusses the basis for left-to-right shunt therapies, synthesizes past and ongoing clinical trials, and offers future directions.

Device-based therapies for heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous syndrome with various causes and a pathophysiology that leads to diverse spectrum of phenotypes. In contrast to a wide range of established treatments for heart failure with reduced ejection fraction (HFrEF), effective medical treatment options for HFpEF are relatively limited with excessively high residual risk of morbidity and mortality. Device-based therapies have emerged as a promising strategy to improve outcomes in patients with HFpEF. Herein, we present data on devices in HFpEF targeting various unique mechanisms including structural inventions, autonomic modulation, and electrophysiologic modulation as well as remote monitoring devices. While early studies of these therapeutic devices have not definitively demonstrated clinical benefits in HFpEF, growing evidence suggests potential benefits in select patient populations for some of these emerging technologies.

Left atrial to coronary sinus shunting in more advanced heart failure with preserved ejection fraction

AIMS

Inter-atrial shunt device therapy has shown mixed results in clinical trials, with clinical 'non-responders' typically showing features of more advanced heart failure. We aimed to analyse the haemodynamic and clinical response of a novel left atrial to coronary sinus (LA-CS) shunt device in patients with higher natriuretic peptide (NP) levels, a marker of disease severity.

METHODS AND RESULTS

An analysis population (n = 95) of patients from the ALT-FLOW early feasibility study with left ventricular ejection fraction >40% and 1-year follow up was analysed. The cohort was divided into low and high subgroups based on NP levels [b-type natriuretic peptide (BNP) and n-terminal pro BNP (NT-proBNP)]. The mean BNP and NT-proBNP levels for low versus high subgroups were 64.2 ± 34.3 versus 261 ± 103 and 322 ± 269 versus 2050 ± 1070 pg/mL, respectively. Patients in the high NP subgroup had evidence of more advanced disease including worse haemodynamic profiles, lower estimated glomerular filtration rate, and higher percentages of atrial fibrillation. The high NP subgroup experienced significant improvements in KCCQ-OSS and NYHA functional class (P < 0.0001 and P < 0.001, respectively) and to a similar magnitude compared with the low NP subgroup. Compared with pre-implant baseline, workload adjusted pulmonary artery wedge pressure at peak exercise declined in the high NP subgroup (PCWL, 164.1 vs. 96.0 mmHg/W/kg at 6 months, P < 0.003) as well as the low NP subgroup (115.9 vs. 65.9 mmHg/W/keg at 6 months, P < 0.001). Importantly, in both NP subgroups, there was preservation of cardiac index through 6 months as well as right ventricular structure (right ventricular diastolic dimension) and function (tricuspid annular systolic plane excursion) through 1 year.

CONCLUSIONS

The quality-of-life, haemodynamic, and functional class improvements along with stable right heart function seen in ALT-FLOW study of LA-CS shunt remain consistent in the subgroup with highest NP levels. This suggests that shunting location could influence outcomes in symptomatic heart failure patients.

Macitentan for Heart Failure With Preserved or Mildly Reduced Ejection Fraction and Pulmonary Vascular Disease: Results of the SERENADE Randomized Clinical Trial and Open-Label Extension Study

BACKGROUND

Despite favorable hemodynamic and neurohormonal effects, endothelin receptor antagonists have not improved outcomes in patients with heart failure (HF), possibly because they cause fluid retention.

METHODS

In this randomized, double-blind, multicenter trial (SERENADE [Macitentan in Heart Failure With Preserved Ejection Fraction and Pulmonary Vascular Disease]), we evaluated the effects of an endothelin receptor antagonist, macitentan, in patients with HF, left ventricular ejection fraction ≥40%, and pulmonary vascular disease. After a 4-week placebo run-in (to ensure clinical stability), followed by a 5-week single-blind macitentan run-in, patients who did not exhibit fluid retention were randomized to macitentan or placebo. The primary end point was change in NT-proBNP (N-terminal pro-B-type natriuretic peptide; baseline to 24 weeks); secondary end points included change in KCCQ (Kansas City Cardiomyopathy Questionnaire) clinical summary score (baseline to 24 weeks) and time to worsening HF by 52 weeks.

RESULTS

Of 230 patients enrolled, 28 were excluded during the placebo run-in, 60 excluded during the macitentan run-in, and 142 were randomized. Macitentan had no effect on change in NT-proBNP (geometric mean ratio [macitentan/placebo], 1.02 [90% CI, 0.88-1.19]; P=0.79) or on secondary end points (placebo-corrected change in KCCQ clinical summary score, -3.5 [90% CI, -8.2 to +1.2]; P=0.22). Worsening HF occurred in 20 (28%) patients assigned to macitentan and 13 (18%) assigned to placebo (hazard ratio, 1.48 [90% CI, 0.83-2.67]; P=0.24). More macitentan-treated patients developed fluid retention (16 [23%] versus 10 [14%]) and cardiac adverse events (33 [46%] versus 22 [31%]) versus placebo.

CONCLUSIONS

Despite a novel enrichment trial design to target pulmonary vascular disease and exclude treatment-related fluid retention in patients with HF and preserved/mildly reduced left ventricular ejection fraction, macitentan neither lowered NT-proBNP nor improved HF outcomes.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifiers: NCT03153111 and NCT03714815.

Left Atrial-to-Coronary Sinus Shunting in Heart Failure With Mildly Reduced or Preserved Ejection Fraction: The ALT-FLOW Trial (Early Feasibility Study) 2-Year Results

BACKGROUND

The ALT-FLOW trial EFS (Early Feasibility Study) evaluated safety, hemodynamics and outcomes for the APTURE system in patients with HF and mildly reduced or preserved ejection fraction.

OBJECTIVES

In this study, the authors sought to examine the 2-year health status, functional capacity, and outcomes of ALT-FLOW EFS.

METHODS

Device safety, performance, patency, hemodynamics, echocardiographic parameters, and outcomes were assessed in patients with LVEF >40% (n = 95); NYHA functional class, Kansas City Cardiomyopathy Questionnaire (KCCQ) Clinical Summary Score (CSS), Total Symptom Score (TSS), and Overall Summary Score (OSS), 6-minute walk distance, and the ratio of pulmonary capillary wedge pressure at peak exercise to workload normalized to body weight (PCWL) were evaluated.

RESULTS

Major adverse cardiac, cerebral, and renal events and reintervention through 30 days occurred in 2.8% of patients. All implanted shunts were patent for up to 5 years. The mean PCWL decreased from 131 ± 74 mm Hg/W/kg at baseline to 76 ± 57 mm Hg/W/kg after 6 months (P < 0.0001). After 2 years, NYHA functional class improvement was reported in 51/62 patients (82.3%). Mean KCCQ CSS, TSS, and OSS at baseline were 45 ± 17, 46 ± 19, and 38 ± 18 points, respectively, and improved at 2 years by 25 ± 20, 26 ± 23, and 31 ± 23 points, respectively. The reduction in PCWL and improvement in NYHA functional class and KCCQ scores were consistent in patients with or without pulmonary vascular disease. No detrimental changes in right or left ventricular function were observed.

CONCLUSIONS

In patients with HF and LVEF >40%, the APTURE shunt confirmed an acceptable safety profile with improvements in HF symptoms, quality of life, and functional capacity without negatively affecting right and left heart function after 2 years, regardless of pulmonary vascular disease. (Exploratory Study of the Edwards APTURE Transcatheter Shunt System [ALT-FLOW Canada]; NCT04000607; Early Feasibility Study-Edwards APTURE Transcatheter Shunt System [ALT-FLOW US]; NCT03523416).

Left atrial shunting devices: why, what, how, and… when?

Left atrial (LA) hypertension is central in the pathophysiology of heart failure (HF) in general and of HF with preserved ejection fraction (HFpEF) in particular. Despite approved treatments, a number of HF patients continue experiencing disabling symptoms due to LA hypertension, causing pulmonary congestion, pulmonary hypertension, and right heart dysfunction, at rest and/or during exercise. LA decompression therapies, i.e., left atrial shunting through a specifically designed device (either implant-based or implant-free), are being studied in various forms of HF to alleviate LA hypertension and patients' symptoms. Despite a solid background and favorable signals from initial non-randomized clinical trials, the quest for the optimal HF candidate for interatrial shunt devices is still an area of active research that at the same time is helping to better elucidate the intricate pathophysiology of HF(pEF).

Interatrial Shunt Treatment for Heart Failure: The Randomized RELIEVE-HF Trial

BACKGROUND

An interatrial shunt may provide an autoregulatory mechanism to decrease left atrial pressure and improve heart failure (HF) symptoms and prognosis.

METHODS

Patients with symptomatic HF with any left ventricular ejection fraction (LVEF) were randomized 1:1 to transcatheter shunt implantation versus a placebo procedure, stratified by reduced (≤40%) versus preserved (>40%) LVEF. The primary safety outcome was a composite of device-related or procedure-related major adverse cardiovascular or neurological events at 30 days compared with a prespecified performance goal of 11%. The primary effectiveness outcome was the hierarchical composite ranking of all-cause death, cardiac transplantation or left ventricular assist device implantation, HF hospitalization, outpatient worsening HF events, and change in quality of life from baseline measured by the Kansas City Cardiomyopathy Questionnaire overall summary score through maximum 2-year follow-up, assessed when the last enrolled patient reached 1-year follow-up, expressed as the win ratio. Prespecified hypothesis-generating analyses were performed in patients with reduced and preserved LVEF.

RESULTS

Between October 24, 2018, and October 19, 2022, 508 patients were randomized at 94 sites in 11 countries to interatrial shunt treatment (n=250) or a placebo procedure (n=258). Median (25th and 75th percentiles) age was 73.0 years (66.0, 79.0), and 189 patients (37.2%) were women. Median LVEF was reduced (≤40%) in 206 patients (40.6%) and preserved (>40%) in 302 patients (59.4%). No primary safety events occurred after shunt implantation (upper 97.5% confidence limit, 1.5%; P<0.0001). There was no difference in the 2-year primary effectiveness outcome between the shunt and placebo procedure groups (win ratio, 0.86 [95% CI, 0.61-1.22]; P=0.20). However, patients with reduced LVEF had fewer adverse cardiovascular events with shunt treatment versus placebo (annualized rate 49.0% versus 88.6%; relative risk, 0.55 [95% CI, 0.42-0.73]; P<0.0001), whereas patients with preserved LVEF had more cardiovascular events with shunt treatment (annualized rate 60.2% versus 35.9%; relative risk, 1.68 [95% CI, 1.29-2.19]; P=0.0001; Pinteraction<0.0001). There were no between-group differences in change in Kansas City Cardiomyopathy Questionnaire overall summary score during follow-up in all patients or in those with reduced or preserved LVEF.

CONCLUSIONS

Transcatheter interatrial shunt implantation was safe but did not improve outcomes in patients with HF. However, the results from a prespecified exploratory analysis in stratified randomized groups suggest that shunt implantation is beneficial in patients with reduced LVEF and harmful in patients with preserved LVEF.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03499236.

[The Role of the Left Atrium in the Pathogenesis of Heart Failure With Preserved Ejection Fraction]

Left atrial dysfunction (left atrial myopathy) is not only a consequence of impaired left ventricular diastolic function but also plays a central role in the pathophysiology of heart failure with preserved ejection fraction (HFpEF). Left atrial myopathy in HFpEF is associated with a more severe course of heart failure and an unfavorable prognosis, and the choice of treatment largely depends on its severity. Echocardiography allows an accurate assessment of the left atrial condition, while the parameters of left atrial myocardial strain are sensitive to early functional disorders to help diagnosing HFpEF and determining the prognosis. This article discusses the participation of the left atrium in the left ventricular filling, its status at different stages of left ventricular diastolic dysfunction, the major mechanisms of atrial myopathy in HFpEF, and therapeutic approaches to its restriction and reversion.

HFSA Scientific Statement: Update on Device Based Therapies in Heart Failure

Heart failure (HF) is 1 of the major challenges of our time, given its increase in prevalence and related mortality rates. Foundational pharmacological therapies, including angiotensin receptor neprilysin inhibitors (ARNIs), beta-blockers, mineralocorticoid receptor antagonists (MRAs), and sodium-glucose co-transporter inhibitors (SGLTis), have been established for HF with reduced ejection fraction (HFrEF). Moreover, recent trials have established the role of SGLTis in patients with HF with preserved ejection fraction (HFpEF). However, even with these therapies, a substantial residual risk persists in both HFrEF and HFpEF. Alongside pharmacological advancements, device-based therapies have shown efficacy in HF management, including implantable cardioverter-defibrillators (ICDs) and cardiac resynchronization therapy (CRT). More recently, devices such as cardiac contractility modulation (CCM) and baroreflex activation therapy (BAT) have been approved by the FDA, although they lack comprehensive guideline recommendations. This scientific statement outlines the unmet needs in chronic HF, reviews contemporary data and provides a framework for integrating novel device-based therapies into current clinical workflows. It emphasizes the importance of early diagnosis and phenotyping, proper patient stratification and a personalized approach to combining pharmacological and device therapies. The document also highlights the need for further research into device interactions and patient selection to optimize outcomes, while recognizing the need for a more integrated approach to treatment so as to address the unmet needs and residual risks in HF management.

Imaging and mechanisms of heart failure with preserved ejection fraction: a state-of-the-art review

Understanding of the pathophysiology of heart failure with preserved ejection fraction (HFpEF) has advanced rapidly over the past two decades. Currently, HFpEF is recognized as a heterogeneous syndrome, and there is a growing movement towards developing personalized treatments based on phenotype-guided strategies. Left ventricular dysfunction is a fundamental pathophysiological abnormality in HFpEF; however, recent evidence also highlights significant roles for the atria, right ventricle, pericardium, and extracardiac contributors. Imaging plays a central role in characterizing these complex and highly integrated domains of pathophysiology. This review focuses on established evidence, recent insights, and the challenges that need to be addressed concerning the pathophysiology of HFpEF, with a focus on imaging-based evaluations and opportunities for further research.

Pulmonary hypertension associated with left heart disease

Left heart disease (LHD) is the most common cause of pulmonary hypertension (PH), which may be classified further as isolated post-capillary (ipcPH) or combined post- and pre-capillary PH (cpcPH). The 7th World Symposium on Pulmonary Hypertension PH-LHD task force reviewed newly reported randomised clinical trials and contemplated novel opportunities for improving outcome. Results from major randomised clinical trials reinforced prior recommendations against the use of pulmonary arterial hypertension therapy in PH-LHD outside of clinical trials, and suggested possible harm. Greater focus on phenotyping was viewed as one general strategy by which to ultimately improve clinical outcomes. This is potentially achievable by individualising ipcPH versus cpcPH diagnosis for patients with pulmonary arterial wedge pressure within a diagnostic grey zone (12-18 mmHg), and through a newly developed PH-LHD staging system. In this model, PH accompanies LHD across four stages (A=at risk, B=structural heart disease, C=symptomatic heart disease, D=advanced), with each stage characterised by progression in clinical characteristics, haemodynamics and potential therapeutic strategies. Along these lines, the task force proposed disaggregating PH-LHD to emphasise specific subtypes for which PH prevalence, pathophysiology and treatment are unique. This includes re-interpreting mitral and aortic valve stenosis through a contemporary lens, and focusing on PH within the hypertrophic cardiomyopathy and amyloid cardiomyopathy clinical spectra. Furthermore, appreciating LHD in the profile of PH patients with chronic lung disease and chronic thromboembolic pulmonary disease is essential. However, engaging LHD patients in clinical research more broadly is likely to require novel methodologies such as pragmatic trials and may benefit from next-generation analytics to interpret results.

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.

Heart failure with preserved ejection fraction: diagnosis, risk assessment, and treatment

The aetiology of heart failure with preserved ejection fraction (HFpEF) is heterogenous and overlaps with that of several comorbidities like atrial fibrillation, diabetes mellitus, chronic kidney disease, valvular heart disease, iron deficiency, or sarcopenia. The diagnosis of HFpEF involves evaluating cardiac dysfunction through imaging techniques and assessing increased left ventricular filling pressure, which can be measured directly or estimated through various proxies including natriuretic peptides. To better narrow down the differential diagnosis of HFpEF, European and American heart failure guidelines advocate the use of different algorithms including comorbidities that require diagnosis and rigorous treatment during the evaluation process. Therapeutic recommendations differ between guidelines. Whilst sodium glucose transporter 2 inhibitors have a solid evidence base, the recommendations differ with regard to the use of inhibitors of the renin-angiotensin-aldosterone axis. Unless indicated for specific comorbidities, the use of beta-blockers should be discouraged in HFpEF. The aim of this article is to provide an overview of the current state of the art in HFpEF diagnosis, clinical evaluation, and treatment.

Dapagliflozin and Right Ventricular-Pulmonary Vascular Interaction in Heart Failure With Preserved Ejection Fraction: A Secondary Analysis of a Randomized Clinical Trial

Importance

Increases in pulmonary capillary wedge pressure (PCWP) during exercise reduce pulmonary artery (PA) compliance, increase pulsatile right ventricular (RV) afterload, and impair RV-PA coupling in patients with heart failure with preserved ejection fraction (HFpEF). The effects of the sodium-glucose cotransporter 2 (SGLT2) inhibitor dapagliflozin on pulmonary vascular properties and RV-PA coupling are unknown.

Objective

To test the effect of dapagliflozin on right ventricular performance and pulmonary vascular load during exertion in HFpEF.

Design, Setting, and Participants

Evaluation of the Cardiac and Metabolic Effects of Dapagliflozin in Heart Failure With Preserved Ejection Fraction (CAMEO-DAPA) randomized clinical trial demonstrated improvement in PCWP at rest and exercise over 24 weeks with dapagliflozin compared with placebo with participants recruited between February 2021 and May 2022. This secondary analysis evaluates the effects of dapagliflozin on pulsatile pulmonary vascular load and RV-PA coupling using simultaneous echocardiography and high-fidelity invasive hemodynamic testing with exercise. This was a single-center study including patients with hemodynamically confirmed HFpEF with exercise PCWP of 25 mm Hg or greater.

Interventions

Dapagliflozin or placebo for 24 weeks.

Main Outcomes and Measures

Pulsatile pulmonary vascular load (PA compliance and elastance) and right ventricular performance (PA pulsatility index, RV systolic velocity [s']/PA mean) during rest and exercise.

Results

Among 37 randomized participants (mean [SD] age, 67.4 [8.5] years; 25 female [65%]; mean [SD] body mass index, 34.9 [6.7]; calculated as weight in kilograms divided by height in meters squared), there was no effect of dapagliflozin on PA loading or RV-PA interaction at rest. However, with exercise, dapagliflozin improved PA compliance (placebo-corrected mean difference, 0.57 mL/mm Hg; 95% CI, 0.11-1.03 mL/mm Hg; P = .02) and decreased PA elastance (stiffness; -0.17 mm Hg/mL; 95% CI, -0.28 to -0.07 mm Hg/mL; P = .001). RV function during exercise improved, with increase in PA pulsatility index (0.33; 95% CI, 0.08-0.59; P = .01) and increase in exercise RV s' indexed to PA pressure (0.09 cm·s-1/mm Hg; 95% CI, 0.02-0.16 cm·s-1/mm Hg; P = .01). Improvements in pulsatile RV load and RV-PA coupling were correlated with reduction in right atrial (RA) pressure (PA elastance Pearson r = 0.55; P =.008; RV s'/PA elastance Pearson r = -0.60; P =.002) and PCWP (PA elastance Pearson r = 0.58; P <.001; RV s'/PA elastance Pearson r = -0.47; P = .02). Dapagliflozin increased resistance-compliance time (dapagliflozin, median [IQR] change, 0.06 [0.03-0.15] seconds; placebo, median [IQR] change, 0.01 [-0.02 to 0.05] seconds; P =.046), resulting in higher PA compliance for any exercise pulmonary vascular resistance.

Conclusions and Relevance

Results of this randomized clinical trial reveal that treatment with dapagliflozin for 24 weeks reduced pulsatile pulmonary vascular load and enhanced dynamic RV-PA interaction during exercise in patients with HFpEF, findings that are related to the magnitude of PCWP reduction. Benefits on dynamic right ventricular-pulmonary vascular coupling may partially explain the benefits of SGLT2 inhibitors in HFpEF.

Trial Registration

ClinicalTrials.gov Identifier: NCT04730947.

Nonpharmacological Approaches to Managing Heart Failure With Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) is a common subtype of heart failure marked by impaired left ventricular diastolic function and decreased myocardial compliance. Given the limited availability of evidence-based pharmacological treatments for HFpEF, there is a growing interest in nonpharmacological interventions as viable therapeutic alternatives. This review aims to explore the pathophysiology of HFpEF and present recent advancements in nonpharmacological management approaches, encompassing noninvasive therapies, invasive procedures and targeted treatments for comorbidities. An extensive literature review was undertaken to identify and synthesize emerging nonpharmacological treatment options for HFpEF, assessing their potential to enhance patient outcomes. Nonpharmacological strategies, such as vagus nerve stimulation, percutaneous pulmonary artery denervation, renal denervation, transcatheter insertion of atrial shunts and pericardial resection, demonstrate promising potential for alleviating HFpEF symptoms and improving patient prognosis. Moreover, addressing comorbidities, such as hypertension and diabetes, may offer additional therapeutic benefits. These cutting-edge techniques, in conjunction with well-established exercise therapies, pave the way for future research and clinical applications in the field. Nonpharmacological interventions hold promise for advancing HFpEF patient care and fostering a deeper understanding of these treatment approaches, which will facilitate new clinical applications and contribute to the development of more targeted therapies.

2-Year Outcomes of an Atrial Shunt Device in HFpEF/HFmrEF: Results From REDUCE LAP-HF II

BACKGROUND

The REDUCE LAP-HF II (Reduce Elevated Left Atrial Pressure in Patients With Heart Failure II) trial found that, compared with a sham procedure, the Corvia Atrial Shunt did not improve outcomes in heart failure with preserved or mildly reduced ejection fraction. However, after 12-month follow-up, "responders" (peak-exercise pulmonary vascular resistance <1.74 WU and absence of a cardiac rhythm management device) were identified.

OBJECTIVES

This study sought to determine: 1) the overall efficacy and safety of the atrial shunt vs sham control after 2 years of follow-up; and 2) whether the benefits of atrial shunting are sustained in responders during longer-term follow-up or are offset by adverse effects of the shunt.

METHODS

The study analyzed 2-year outcomes in the overall REDUCE LAP-HF II trial, as well as in responder and nonresponder subgroups. The primary endpoint was a hierarchical composite of cardiovascular death or nonfatal ischemic/embolic stroke, total heart failure events, and change in health status.

RESULTS

In 621 randomized patients, there was no difference between the shunt (n = 309) and sham (n = 312) groups in the primary endpoint (win ratio: 1.01 [95% CI: 0.82-1.24]) or its individual components at 2 years. Shunt patency at 24 months was 98% in shunt-treated patients. Cardiovascular mortality and nonfatal ischemic stroke were not different between the groups; however, major adverse cardiac events were more common in those patients assigned to the shunt compared with sham (6.9% vs 2.7%; P = 0.018). More patients randomized to the shunt had an increase in right ventricular volume of ≥30% compared with the sham control (39% vs 28%, respectively; P < 0.001), but right ventricular dysfunction was uncommon and not different between the treatment groups. In responders (n = 313), the shunt was superior to sham (win ratio: 1.36 [95% CI: 1.02-1.83]; P = 0.037, with 51% fewer HF events [incidence rate ratio: 0.49 [95% CI: 0.25-0.95]; P = 0.034]). In nonresponders (n = 265), atrial shunting was inferior to sham (win ratio: 0.73 [95% CI: 0.54-0.98]).

CONCLUSIONS

At 2 years of follow-up in REDUCE LAP-HF II, there was no difference in efficacy between the atrial shunt and sham groups in the overall trial group. The potential clinical benefit identified in the responder group after 1 and 2 years of follow-up is currently being evaluated in the RESPONDER-HF (Re-Evaluation of the Corvia Atrial Shunt Device in a Precision Medicine Trial to Determine Efficacy in Mildly Reduced or Preserved Ejection Fraction Heart Failure) trial. (Reduce Elevated Left Atrial Pressure in Patients With Heart Failure II [REDUCE LAP-HF II]; NCT03088033).

Beyond Medical Therapy-An Update on Heart Failure Devices

Heart failure (HF) is a complex and progressive disease marked by substantial morbidity and mortality rates, frequent episodes of decompensation, and a reduced quality of life (QoL), with severe financial burden on healthcare systems. In recent years, several large-scale randomized clinical trials (RCTs) have widely expanded the therapeutic armamentarium, underlining additional benefits and the feasibility of rapid titration regimens. This notwithstanding, mortality is not declining, and hospitalizations are constantly increasing. It is widely acknowledged that even with guideline-directed medical therapy (GDMT) on board, HF patients have a prohibitive residual risk, which highlights the need for innovative treatment options. In this scenario, groundbreaking devices targeting valvular, structural, and autonomic abnormalities have become crucial tools in HF management. This has led to a full-fledged translational boost with several novel devices in development. Thus, the aim of this review is to provide an update on both approved and investigated devices.

Atrial Shunt Device Effects on Cardiac Structure and Function in Heart Failure With Preserved Ejection Fraction: The REDUCE LAP-HF II Randomized Clinical Trial

Importance

Although the results of A Study to Evaluate the Corvia Medical Inc IASD System II to Reduce Elevated Left Atrial Pressure in Patients with Heart Failure (REDUCE LAP-HF II) trial were neutral overall, atrial shunt therapy demonstrated potential efficacy in responders (no latent pulmonary vascular disease and no cardiac rhythm management device). Post hoc analyses were conducted to evaluate the effect of shunt vs sham stratified by responder status.

Objective

To evaluate the effect of atrial shunt vs sham control on cardiac structure/function in the overall study and stratified by responder status.

Design, Setting, and Participants

This was a sham-controlled randomized clinical trial of an atrial shunt device in heart failure with preserved ejection fraction (HFpEF)/HF with mildly reduced EF (HFmrEF). Trial participants with evaluable echocardiography scans were recruited from 89 international medical centers. Data were analyzed from April 2023 to January 2024.

Interventions

Atrial shunt device or sham control.

Main Outcome Measures

Changes in echocardiographic measures from baseline to 1, 6, 12, and 24 months after index procedure.

Results

The modified intention-to-treat analysis of the REDUCE LAP-HF II trial included 621 randomized patients (median [IQR] age, 72.0 [66.0-77.0] years; 382 female [61.5%]; shunt arm, 309 [49.8%]; sham control arm, 312 [50.2%]). Through 24 months, 212 of 217 patients (98%) in the shunt arm with evaluable echocardiograms had patent shunts. In the overall trial population, the shunt reduced left ventricular (LV) end-diastolic volume (mean difference, -5.65 mL; P <.001), left atrial (LA) minimal volume (mean difference, -2.8 mL; P =.01), and improved LV systolic tissue Doppler velocity (mean difference, 0.69 cm/s; P <.001) and LA emptying fraction (mean difference, 1.88 percentage units; P =.02) compared with sham. Shunt treatment also increased right ventricular (RV; mean difference, 9.58 mL; P <.001) and right atrial (RA; mean difference, 9.71 mL; P <.001) volumes but had no effect on RV systolic function, pulmonary artery pressure, or RA pressure compared with sham. In the shunt arm, responders had smaller increases in RV end-diastolic volume (mean difference, 5.71 mL vs 15.18 mL; interaction P =.01), RV end-systolic volume (mean difference, 1.58 mL vs 7.89 mL; interaction P =.002), and RV/LV ratio (mean difference, 0.07 vs 0.20; interaction P <.001) and larger increases in transmitral A wave velocity (mean difference, 5.08 cm/s vs -1.97 cm/s; interaction P =.02) compared with nonresponders randomized to the shunt, suggesting greater ability to accommodate shunted blood through the pulmonary circulation enabling LA unloading.

Conclusions and Relevance

In this post hoc analysis of the REDUCE LAP-HF II trial, over 2 years of follow-up, atrial shunting led to reverse remodeling of left-sided chambers and increases in volume of right-sided chambers consistent with the shunt flow but no change in RV systolic function compared with sham. Changes in cardiac structure/function were more favorable in responders compared with nonresponders treated with the shunt, supporting the previously identified responder group hypothesis and mechanism, although further evaluation with longer follow-up is needed.

Trial Registration

ClinicalTrials.gov Identifier: NCT03088033.

A roadmap for therapeutic discovery in pulmonary hypertension associated with left heart failure. A scientific statement of the Heart Failure Association (HFA) of the ESC and the ESC Working Group on Pulmonary Circulation & Right Ventricular Function

Pulmonary hypertension (PH) associated with left heart failure (LHF) (PH-LHF) is one of the most common causes of PH. It directly contributes to symptoms and reduced functional capacity and negatively affects right heart function, ultimately leading to a poor prognosis. There are no specific treatments for PH-LHF, despite the high number of drugs tested so far. This scientific document addresses the main knowledge gaps in PH-LHF with emphasis on pathophysiology and clinical trials. Key identified issues include better understanding of the role of pulmonary venous versus arteriolar remodelling, multidimensional phenotyping to recognize patient subgroups positioned to respond to different therapies, and conduct of rigorous pre-clinical studies combining small and large animal models. Advancements in these areas are expected to better inform the design of clinical trials and extend treatment options beyond those effective in pulmonary arterial hypertension. Enrichment strategies, endpoint assessments, and thorough haemodynamic studies, both at rest and during exercise, are proposed to play primary roles to optimize early-stage development of candidate therapies for PH-LHF.

Interatrial shunt therapy in advanced heart failure: Outcomes from the open-label cohort of the RELIEVE-HF trial

AIMS

Heart failure (HF) outcomes remain poor despite optimal guideline-directed medical therapy (GDMT). We assessed safety, effectiveness, and transthoracic echocardiographic (TTE) outcomes during the 12 months after Ventura shunt implantation in the RELIEVE-HF open-label roll-in cohort.

METHODS AND RESULTS

Eligibility required symptomatic HF despite optimal GDMT with ≥1 HF hospitalization in the prior year or elevated natriuretic peptides. The safety endpoint was device-related major adverse cardiovascular or neurological events at 30 days, compared to a prespecified performance goal. Effectiveness evaluations included the Kansas City Cardiomyopathy Questionnaire (KCCQ) at baseline, 1, 3, 6, and 12 months and TTE at baseline and 12 months. Overall, 97 patients were enrolled and implanted at 64 sites. Average age was 70 ± 11 years, 97% were in New York Heart Association class III, and half had left ventricular ejection fraction (LVEF) ≤40%. The safety endpoint was achieved (event rate 0%, p < 0.001). KCCQ overall summary score was improved by 12-16 points at all follow-up timepoints (all p < 0.004), with similar outcomes in patients with reduced and preserved LVEF. At 12 months, left ventricular end-systolic and end-diastolic volumes were reduced (p = 0.020 and p = 0.038, respectively), LVEF improved (p = 0.009), right ventricular end-systolic and end-diastolic areas were reduced (p = 0.001 and p = 0.030, respectively), and right ventricular fractional area change (p < 0.001) and tricuspid annular plane systolic excursion (p < 0.001) improved.

CONCLUSION

Interatrial shunting with the Ventura device was safe and resulted in favourable clinical effects in patients with HF, regardless of LVEF. Improvements of left and right ventricular structure and function were consistent with reverse myocardial remodelling. These results would support the potential of this shunt device as a treatment for HF.

Rest and exercise-stress estimated pulmonary capillary wedge pressure using real-time free-breathing cardiovascular magnetic resonance imaging

BACKGROUND

Identification of increased pulmonary capillary wedge pressure (PCWP) by right heart catheterization (RHC) is the reference standard for the diagnosis of heart failure with preserved ejection fraction (HFpEF). Recently, cardiovascular magnetic resonance (CMR) imaging estimation of PCWP at rest was introduced as a non-invasive alternative. Since many patients are only identified during physiological exercise-stress, we hypothesized that novel exercise-stress CMR-derived PCWP emerges superior compared to its assessment at rest.

METHODS

The HFpEF-Stress Trial prospectively recruited 75 patients with exertional dyspnea and diastolic dysfunction who then underwent rest and exercise-stress RHC and CMR. HFpEF was defined according to PCWP (overt HFpEF ≥15 mmHg at rest, masked HFpEF ≥25 mmHg during exercise-stress). CMR-derived PCWP was calculated based on previously published formula using left ventricular mass and either biplane left atrial volume (LAV) or monoplane left atrial area (LAA).

RESULTS

LAV (rest/stress: r = 0.50/r = 0.55, p < 0.001) and LAA PCWP (rest/stress: r = 0.50/r = 0.48, p < 0.001) correlated significantly with RHC-derived PCWP while numerically overestimating PCWP at rest and underestimating PCWP during exercise-stress. LAV and LAA PCWP showed good diagnostic accuracy to detect HFpEF (area under the receiver operating characteristic curve (AUC) LAV rest 0.73, stress 0.81; LAA rest 0.72, stress 0.77) with incremental diagnostic value for the detection of masked HFpEF using exercise-stress (AUC LAV rest 0.54 vs stress 0.67, p = 0.019, LAA rest 0.52 vs stress 0.66, p = 0.012). LAV but not LAA PCWP during exercise-stress was a predictor for 24 months hospitalization independent of a medical history for atrial fibrillation (hazard ratio (HR) 1.26, 95% confidence interval 1.02-1.55, p = 0.032).

CONCLUSION

Non-invasive PCWP correlates well with the invasive reference at rest and during exercise stress. There is overall good diagnostic accuracy for HFpEF assessment using CMR-derived estimated PCWP despite deviations in absolute agreement. Non-invasive exercise derived PCWP may particularly facilitate detection of masked HFpEF in the future.

Advances in device-based treatment of heart failure with preserved ejection fraction: evidence from clinical trials

Heart failure with preserved ejection fraction (HFpEF) is a group of clinical syndromes that exhibit a remarkably heterogeneous phenotype, characterized by symptoms and signs of heart failure, left ventricular diastolic dysfunction, elevated levels of natriuretic peptides, and an ejection fraction greater than or equal to 50%. With the aging of the population and the escalating prevalence of hypertension, obesity, and diabetes, the incidence of HFpEF is progressively rising. Drug therapy options for HFpEF are currently limited, and the associated high risk of cardiovascular mortality and heart failure rehospitalization significantly impact patients' quality of life and longevity while imposing a substantial economic burden on society. Recent research indicates that certain device-based therapies may serve as valuable adjuncts to drug therapy in patients with specific phenotypes of HFpEF, effectively improving symptoms and quality of life while reducing the risk of readmission for heart failure. These include inter-atrial shunt and greater splanchnic nerve ablation to reduce left ventricular filling pressure, implantable heart failure monitor to guide diuresis, left atrial pacing to correct interatrial dyssynchrony, cardiac contractility modulation to enhance cardiac calcium handling, as well as renal denervation, baroreflex activation therapy, and vagus nerve stimulation to restore the autonomic imbalance. In this review, we provide a comprehensive overview of the mechanisms and clinical evidence pertaining to these devices, with the aim of enhancing therapeutic strategies for HFpEF.

Biatrial myopathy in heart failure with preserved ejection fraction

AIM

Left atrial (LA) myopathy is increasingly recognized as an important phenotypic trait in heart failure (HF) with preserved ejection fraction (HFpEF). Right atrial (RA) remodelling and dysfunction also develop in HFpEF, but little data are available regarding the clinical characteristics and pathophysiology among patients with isolated LA, RA, or biatrial myopathy.

METHODS AND RESULTS

Patients with HFpEF underwent invasive haemodynamic exercise testing, comprehensive imaging including speckle tracking strain echocardiography, and clinical follow-up at Mayo Clinic between 2006 and 2018. LA myopathy was defined as LA volume index >34 ml/m2 and/or LA reservoir strain ≤24% and RA myopathy by RA volume index >39 ml/m2 in men and >33 ml/m2 in women and/or RA reservoir strain ≤19.8%. Of 476 consecutively evaluated patients with HFpEF defined by invasive exercise testing with evaluable atrial structure/function, 125 (26%) had no atrial myopathy, 147 (31%) had isolated LA myopathy, 184 (39%) had biatrial myopathy, and 20 (4%) had isolated RA myopathy. Patients with HFpEF and biatrial myopathy had more atrial fibrillation, poorer left ventricular systolic and diastolic function, more severe pulmonary vascular disease, tricuspid regurgitation, ventricular interdependence and right ventricular dysfunction, and poorer cardiac output reserve with exercise. There were 94 patients with events over a median follow-up of 2.9 (interquartile range 1.4-4.6) years. Individuals with biatrial myopathy had an 84% higher risk of HF hospitalization or death as compared to those with isolated LA myopathy (hazard ratio 1.84; 95% confidence interval 1.16-2.92, p = 0.01).

CONCLUSIONS

Biatrial myopathy identifies patients with more advanced HFpEF characterized by more severe pulmonary vascular disease, right HF, poorer cardiac reserve, and a greater risk for adverse outcomes. Further study is required to define optimal strategies to treat and prevent biatrial myopathy in HFpEF.

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.

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.

Obesity in heart failure with preserved ejection fraction: Insights from the REDUCE LAP-HF II trial

AIMS

Obesity is causally related to the development of heart failure with preserved ejection fraction (HFpEF) but complicates the diagnosis and treatment of this disorder. We aimed to determine the relationship between severity of obesity and clinical, echocardiographic and haemodynamic parameters in a large cohort of patients with documented HFpEF.

METHODS AND RESULTS

The REDUCE LAP-HF II trial randomized 626 patients with ejection fraction ≥40% and exercise pulmonary capillary wedge pressure (PCWP) ≥25 mmHg to atrial shunt or sham procedure. We tested for associations between body mass index (BMI), clinical characteristics, cardiac structural and functional abnormalities, physical limitations, quality of life and outcomes with atrial shunt therapy. Overall, 60.9% of patients had BMI ≥30 kg/m2 . As the severity of obesity increased, symptoms (Kansas City Cardiomyopathy Questionnaire score) and 6-min walk distance worsened. More severe obesity was associated with lower natriuretic peptide levels despite more cardiac remodelling, higher cardiac filling pressures, and higher cardiac output. Lower cut points for E/e' were needed to identify elevated PCWP in more obese patients. Strain measurements in all four chambers were maintained as BMI increased. Pulmonary vascular resistance at rest and exercise decreased with higher BMI. Obesity was associated with more first and recurrent heart failure events. However, there was no significant interaction between obesity and treatment effects of the atrial shunt.

CONCLUSIONS

Increasing severity of obesity was associated with greater cardiac remodelling, higher right and left ventricular filling pressures, higher cardiac output and increased subsequent heart failure events. Despite significant obesity, many HFpEF patients have preserved right heart and pulmonary vascular function and thus, may be appropriate candidates for atrial shunt therapy.

Rationale and design of the PACE HFpEF trial: Physiologic accelerated pacing as a holistic treatment of heart failure with preserved ejection fraction

Background

In heart failure with preserved ejection fraction (HFpEF), it has been assumed that pharmacologic heart rate suppression should provide clinical benefits through an increase in diastolic filling time. Contrary to this assumption, heart rate lowering in patients with preserved left ventricular ejection fraction and hypertension or coronary artery disease results in adverse outcomes and suggests that the opposite may be beneficial. Namely, shortening the diastolic filling time with a higher heart rate might normalize the elevated filling pressures that are the sine qua non of HFpEF. Initial clinical studies that assessed the effects of accelerated heart rates in pacemaker patients with preclinical and overt HFpEF provide support for this latter hypothesis, having shown improvements in quality of life, natriuretic peptide and activity levels, and atrial fibrillation burden.

Objective

The study sought to determine the effects of continued resting heart rate elevation with and without superimposed nocturnal pacing in HFpEF patients without standard pacing indication.

Methods

The physiologic accelerated pacing as treatment for heart failure with preserved ejection fraction (PACE HFpEF) trial is an investigator-initiated, prospective, patient-blinded multiple crossover pilot study that assesses the impact of accelerated pacing on quality of life, physical activity, N-terminal pro-B-type natriuretic peptide, and echocardiographic measures of cardiac structure and function.

Results

Twenty patients were enrolled and underwent dual-chamber pacemaker implantation under U.S. Food and Drug Administration investigational device exemption with both atrial and ventricular physiologic lead placement targeting the Bachmann bundle and the His bundle.

Conclusion

This manuscript describes the rationale and design of the PACE HFpEF trial, which tests the safety and feasibility of continuous accelerated physiological pacing as a treatment strategy in HFpEF.

Pulmonary Hypertension Associated with Left Heart Disease

Pulmonary hypertension (PH) is a common complication of diseases affecting the left heart, mostly found in patients suffering from heart failure, with or without preserved left ventricular ejection fraction. Initially driven by a passive increase in left atrial pressure (postcapillary PH), several mechanisms may lead in a subset of patient to significant structural changes of the pulmonary vessels or a precapillary component. In addition, the right ventricle may be independently affected, which results in right ventricular to pulmonary artery uncoupling and right ventricular failure, all being associated with a worse outcome. The differential diagnosis of PH associated with left heart disease versus pulmonary arterial hypertension (PAH) is especially challenging in patients with cardiovascular comorbidities and/or heart failure with preserved ejection fraction (HFpEF). A stepwise approach to diagnosis is proposed, starting with a proper clinical multidimensional phenotyping to identify patients in whom hemodynamic confirmation is deemed necessary. Provocative testing (exercise testing, fluid loading, or simple leg raising) is useful in the cath laboratory to identify patients with abnormal response who are more likely to suffer from HFpEF. In contrast with group 1 PH, management of PH associated with left heart disease must focus on the treatment of the underlying condition. Some PAH-approved targets have been unsuccessfully tried in clinical studies in a heterogeneous group of patients, some even leading to an increase in adverse events. There is currently no approved therapy for PH associated with left heart disease.

[Pulmonary hypertension associated with left heart disease (group 2)]

Pulmonary hypertension associated with left heart disease (PH-LHD) corresponds to group two of pulmonary hypertension according to clinical classification. Haemodynamically, this group includes isolated post-capillary pulmonary hypertension (IpcPH) and combined post- and pre-capillary pulmonary hypertension (CpcPH). PH-LHD is defined by an mPAP > 20 mmHg and a PAWP > 15 mmHg, pulmonary vascular resistance (PVR) with a cut-off value of 2 Wood Units (WU) is used to differentiate between IpcPH and CpcPH. A PVR greater than 5 WU indicates a dominant precapillary component. PH-LHD is the most common form of pulmonary hypertension, the leading cause being left heart failure with preserved (HFpEF) or reduced ejection fraction (HFmrEF, HFrEF), valvular heart disease and, less commonly, congenital heart disease. The presence of pulmonary hypertension is associated with increased symptom burden and poorer outcome across the spectrum of left heart disease. Differentiating between group 1 pulmonary hypertension with cardiac comorbidities and PH-LHD, especially due to HFpEF, is a particular challenge. Therapeutically, no general recommendation for the use of PDE5 inhibitors in HFpEF-associated CpcPH can be made at this time. There is currently no reliable rationale for the use of PAH drugs in IpcPH, nor is therapy with endothelin receptor antagonists or prostacyclin analogues recommended for all forms of PH-LHD.

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.

Atrial Fibrillation Burden and Atrial Shunt Therapy in Heart Failure With Preserved Ejection Fraction

BACKGROUND

Atrial fibrillation (AF) is a common comorbidity in patients with heart failure with preserved ejection fraction (HFpEF) and in heart failure with mildly reduced ejection fraction (HFmrEF).

OBJECTIVES

This study sought to describe AF burden and its clinical impact among individuals with HFpEF and HFmrEF who participated in a randomized clinical trial of atrial shunt therapy (REDUCE LAP-HF II [A Study to Evaluate the Corvia Medical, Inc IASD System II to Reduce Elevated Left Atrial Pressure in Patients with Heart Failure]) and to evaluate the effect of atrial shunt therapy on AF burden.

METHODS

Study investigators characterized AF burden among patients in the REDUCE LAP-HF II trial by using ambulatory cardiac patch monitoring at baseline (median patch wear time, 6 days) and over a 12-month follow-up (median patch wear time, 125 days). The investigators determined the association of baseline AF burden with long-term clinical events and examined the effect of atrial shunt therapy on AF burden over time.

RESULTS

Among 367 patients with cardiac monitoring data at baseline and follow-up, 194 (53%) had a history of AF or atrial flutter (AFL), and median baseline AF burden was 0.012% (IQR: 0%-1.3%). After multivariable adjustment, baseline AF burden ≥0.012% was significantly associated with heart failure (HF) events (HR: 2.00; 95% CI: 1.17-3.44; P = 0.01) both with and without a history of AF or AFL (P for interaction = 0.68). Adjustment for left atrial reservoir strain attenuated the baseline AF burden-HF event association (HR: 1.71; 95% CI: 0.93-3.14; P = 0.08). Of the 367 patients, 141 (38%) had patch-detected AF during follow-up without a history of AF or AFL. Atrial shunt therapy did not change AF incidence or burden during follow-up.

CONCLUSIONS

In HFpEF and HFmrEF, nearly 40% of patients have subclinical AF by 1 year. Baseline AF burden, even at low levels, is associated with HF events. Atrial shunt therapy does not affect AF incidence or burden. (A Study to Evaluate the Corvia Medical, Inc IASD System II to Reduce Elevated Left Atrial Pressure in Patients with Heart Failure [REDUCE LAP-HF II]; NCT03088033).

Shedding Light on Latent Pulmonary Vascular Disease in Heart Failure With Preserved Ejection Fraction

BACKGROUND

Among patients with heart failure with preserved ejection fraction (HFpEF), a distinct hemodynamic phenotype has been recently described, ie, latent pulmonary vascular disease (HFpEF-latentPVD), defined by exercise pulmonary vascular resistance (PVR) >1.74 WU.

OBJECTIVES

This study aims to explore the pathophysiological significance of HFpEF-latentPVD.

METHODS

The authors analyzed a cohort of patients who had undergone supine exercise right heart catheterization with cardiac output (CO) measured by direct Fick method, between 2016 and 2021. HFpEF-latentPVD patients were compared with HFpEF control patients.

RESULTS

Out of 86 HFpEF patients, 21% qualified as having HFpEF-latentPVD, 78% of whom had PVR >2 WU at rest. Patients with HFpEF-latentPVD were older, with a higher pretest probability of HFpEF, and more frequently experienced atrial fibrillation and at least moderate tricuspid regurgitation (P < 0.05). PVR trajectories differed between HFpEF-latentPVD patients and HFpEF control patients (Pinteraction = 0.008), slightly increasing in the former and reducing in the latter. HFpEF-latentPVD patients displayed more frequent hemodynamically significant tricuspid regurgitation during exercise (P = 0.002) and had more impaired CO and stroke volume reserve (P < 0.05). Exercise PVR was correlated with mixed venous O2 tension (R2 = 0.33) and stroke volume (R2 = 0.31) in HFpEF-latentPVD patients. The HFpEF-latentPVD patients had had higher dead space ventilation during exercise and higher PaCO2 (P < 0.05), which correlated with resting PVR (R2 = 0.21). Event-free survival was reduced in HFpEF-latentPVD patients (P < 0.05).

CONCLUSIONS

The results suggest that when CO is measured by direct Fick, few HFpEF patients have isolated latent PVD (ie, normal PVR at rest, becoming abnormal during exercise). HFpEF-latentPVD patients present with CO limitation to exercise, associated with dynamic tricuspid regurgitation, altered ventilatory control, and pulmonary vascular hyperreactivity, portending a poor prognosis.

Group 2 pulmonary hypertension: from diagnosis to treatment

PURPOSE OF REVIEW

Pulmonary hypertension associated with left heart disease (PHLHD) is common and associated with adverse prognosis. Proper diagnosis is critical to avoid inappropriate treatment. Practical approaches to noninvasive diagnosis are available, though invasive hemodynamics including volume loading or exercise are often necessary for definitive diagnosis. Treatment strategies and research in the field is rapidly evolving.

RECENT FINDINGS

Combined pre and post capillary pulmonary hypertension is associated with remodeling of the pulmonary vasculature that is proportional to the severity of the pulmonary hypertension. Even quite mild elevation of pulmonary vascular resistance (PVR), (greater than 2.0 Wood units (WU)) is associated with adverse outcome. Guideline-directed medical therapy (GDMT) for left heart failure has rapidly evolved, including approval of SGLT2 inhibitors for treatment of heart failure with preserved ejection fraction (HFpEF). However, full implementation of GDMT is lagging. Utilization of implanted pulmonary artery pressure monitoring can facilitate patient management in selected patient phenotypes and has been utilized to demonstrate improvement in pulmonary pressures with emerging therapies in HFpEF including SGLT2 inhibitors and sacubitril/valsartan. A variety of shunt devices to create a left-to-right shunt in order to decompress the left heart are available or undergoing clinical trials. There is concern that there could be adverse response to such devices in patients who have even mild elevation of pulmonary vascular resistance. Sleep disordered breathing is common in PHLHD and should be aggressively sought out and treated.

SUMMARY

Even mild elevation in pulmonary vascular resistance is associated with adverse outcome. A systematic approach to diagnosis of PHLHD is essential. Guideline-directed medical therapy for PHLHD prioritizes optimal management of the left heart disease. Pulmonary artery pressure sensors are useful in selected patients.

Exercise-Induced Left Atrial Hypertension in Heart Failure With Preserved Ejection Fraction

BACKGROUND

Many patients with heart failure and preserved ejection fraction have no overt volume overload and normal resting left atrial (LA) pressure.

OBJECTIVES

This study sought to characterize patients with normal resting LA pressure (pulmonary capillary wedge pressure [PCWP] <15 mm Hg) but exercise-induced left atrial hypertension (EILAH).

METHODS

The REDUCE LAP-HF II (A Study to Evaluate the Corvia Medical, Inc. IASD System II to Reduce Elevated Left Atrial Pressure in Patients With Heart Failure) trial randomized 626 patients with ejection fraction ≥40% and exercise PCWP ≥25 mm Hg to atrial shunt or sham procedure. The primary trial outcome, a hierarchical composite of death, heart failure hospitalization, intensification of diuretics, and change in health status was compared between patients with EILAH and those with heart failure and resting left atrial hypertension (RELAH).

RESULTS

Patients with EILAH (29%) had similar symptom severity, but lower natriuretic peptide levels, higher 6-minute walk distance, less atrial fibrillation, lower left ventricular mass, smaller LA volumes, lower E/e', and better LA strain. PCWP was lower at rest, but had a larger increase with exercise in EILAH. Neither group as a whole had a significant effect from shunt therapy vs sham. Patients with EILAH were more likely to have characteristics associated with atrial shunt responsiveness (peak exercise pulmonary vascular resistance <1.74 WU) and no pacemaker (63% vs 46%; P < 0.001). The win ratio for the primary outcome was 1.56 (P = 0.08) in patients with EILAH and 1.51 (P = 0.04) in those with RELAH when responder characteristics were present.

CONCLUSIONS

Patients with EILAH had similar symptom severity but less advanced myocardial and pulmonary vascular disease. This important subgroup may be difficult to diagnose without invasive exercise hemodynamics, but it has characteristics associated with favorable response to atrial shunt therapy. (A Study to Evaluate the Corvia Medical, Inc. IASD System II to Reduce Elevated Left Atrial Pressure in Patients With Heart Failure [REDUCE LAP-HF TRIAL II]; NCT03088033).

Inferior vena cava diameter is associated with prognosis in patients with chronic heart failure independent of tricuspid regurgitation velocity

AIMS

A high, Doppler-derived, tricuspid regurgitation velocity (TRV) indicates pulmonary hypertension, which may contribute to right ventricular dysfunction and worsening tricuspid regurgitation leading to systemic venous congestion, reflected by an increase in inferior vena cava (IVC) diameter. We hypothesized that venous congestion rather than pulmonary hypertension would be more strongly associated with prognosis.

METHODS AND RESULTS

895 patients with chronic heart failure (CHF) (median (25th and 75th centile) age 75 (67-81) years, 69% men, LVEF 44 (34-55)% and NT-proBNP 1133 (423-2465) pg/ml) were enrolled. Compared to patients with normal IVC (< 21 mm) and TRV (≤ 2.8 m/s; n = 504, 56%), those with high TRV but normal IVC (n = 85, 9%) were older, more likely to be women and to have LVEF ≥ 50%, whilst those with dilated IVC but normal TRV (n = 142, 16%) had more signs of congestion and higher NT-proBNP. Patients (n = 164, 19%) with both dilated IVC and high TRV had the most signs of congestion and the highest NT-proBNP. During follow-up of 860 (435-1121) days, 239 patients died. Compared to those with both normal IVC and TRV (reference), patients with high TRV but normal IVC did not have a significantly increased mortality (HR: 1.41; CI: 0.87-2.29; P = 0.16). Risk was higher for patients with a dilated IVC but normal TRV (HR: 2.51; CI: 1.80-3.51; P < 0.001) or both a dilated IVC and elevated TRV (HR: 3.27; CI: 2.40-4.46; P < 0.001).

CONCLUSION

Amongst ambulatory patients with CHF, a dilated IVC is more closely associated with an adverse prognosis than an elevated TRV.

No-Implant Interatrial Shunt for HFpEF: 6-Month Outcomes From Multicenter Pilot Feasibility Studies

BACKGROUND

Most approaches to the creation of an interatrial shunt require placement of a permanent implant to maintain patency.

OBJECTIVES

The goal of this study was to investigate the safety and efficacy of a no-implant interatrial shunt for patients with heart failure with preserved ejection fraction (HFpEF) and heart failure with mildly reduced ejection fraction (HFmrEF).

METHODS

This was a multicenter, uncontrolled study of patients with HFpEF/HFmrEF and NYHA functional class ≥II, ejection fraction >40%, and pulmonary capillary wedge pressure (PCWP) during supine exercise ≥25 mm Hg with PCWP-to-right atrial gradient ≥5 mm Hg. Follow-up was through 6 months with imaging to assess shunt durability.

RESULTS

A total of 28 patients were enrolled: mean age was 68 ± 9 years, and 68% were female. Baseline resting and peak exercise PCWP were 19 ± 7 mm Hg and 40 ± 11 mm Hg, respectively. All procedures displayed technical success with confirmation of left-to-right flow (shunt diameter 7.1 ± 0.9 mm). At 1 month, peak exercise PCWP decreased 5.4 ± 9.6 mm Hg (P = 0.011) with no change in right atrial pressure. There were no serious device or procedure-related adverse events through 6 months. Mean 6-minute walk distance increased 101 ± 71 meters (P < 0.001); Kansas City Cardiomyopathy Questionnaire Overall Summary Score increased 26 ± 19 points (P < 0.001); N-terminal pro-B-type natriuretic peptide decreased 372 ± 857 pg/mL (P = 0.018); and shunt patency was confirmed with unchanged diameter.

CONCLUSIONS

In these feasibility studies of a no-implant interatrial shunt, HFpEF/HFmrEF shunts exhibited stability with favorable safety and early efficacy signals. The results show promise toward this new approach for treating patients with HFpEF/HFmrEF and an appropriate hemodynamic profile. (Evaluation of the Safety and Feasibility of a Percutaneously Created Interatrial Shunt to Alleviate Heart Failure Symptoms in Patients With Chronic Heart Failure and Preserved or Mid-Range Left Ventricular Ejection Fraction [ALLEVIATE-HF-1]; NCT04583527; Evaluation of the Safety and Effectiveness of a Percutaneously Created Interatrial Shunt to Alleviate Heart Failure Symptoms in Patients With Chronic Heart Failure and Preserved or Mid-Range Left Ventricular Ejection Fraction [ALLEVIATE-HF-2]; NCT04838353).