A transcatheter intracardiac shunt device for heart failure with preserved ejection fraction (REDUCE LAP-HF): a multicentre, open-label, single-arm, phase 1 trial

Renal Denervation to Treat Heart Failure

Heart failure (HF) is a global pandemic with a poor prognosis after hospitalization. Despite HF syndrome complexities, evidence of significant sympathetic overactivity in the manifestation and progression of HF is universally accepted. Confirmation of this dogma is observed in guideline-directed use of neurohormonal pharmacotherapies as a standard of care in HF. Despite reductions in morbidity and mortality, a growing patient population is resistant to these medications, while off-target side effects lead to dismal patient adherence to lifelong drug regimens. Novel therapeutic strategies, devoid of these limitations, are necessary to attenuate the progression of HF pathophysiology while continuing to reduce morbidity and mortality. Renal denervation is an endovascular procedure, whereby the ablation of renal nerves results in reduced renal afferent and efferent sympathetic nerve activity in the kidney and globally. In this review, we discuss the current state of preclinical and clinical research related to renal sympathetic denervation to treat HF.

Haemodynamics of an iatrogenic atrial septal defect after MitraClip implantation

BACKGROUND

The MitraClip procedure requires transseptal access of the left atrium with a 24F guiding sheath. We evaluated invasively whether a MitraClip induced iatrogenic atrial septal defect (IASD) leads to development of a relevant interatrial shunt and right ventricular overload.

METHODS

A total of 69 patients who underwent a MitraClip procedure due to a severe mitral valve regurgitation (MVR) were included in the observational, retrospective cohort study. All pressures were directly measured throughout the procedure. Cardiac index (CI), systemic (Qs) and pulmonary (Qp) flow were calculated using the Fick method.

RESULTS

Successful MitraClip implantation increased CI (2.5 ± 0.62 vs 3.05 ± 0.77 L/min/m² ; P < .0001), whereas SVR (1491 ± 474 vs 997 ± 301 dyn s/cm⁵ ; P < .0001), PVR (226 ± 121 vs 188 ± 96 dyn/s/cm⁵ ; P = .04), PCWP (23 ± 6.1 vs 20 ± 4.7 mm Hg; P = .0031), PA pressure (33.6 ± 7.2 vs 31.9 ± 6.6 mm Hg; P = .1437) and LA pressure (21.5 ± 5.4 vs 18.7 ± 4.9 mm Hg; P < .0001) all decreased. The effect on LA pressure was further enhanced by guiding catheter retrieval (14.4 ± 4.6 mm Hg; P < .0001). At the end of the procedure, Qp (6.033 ± 1.3 L/min) exceeded Qs (5.537 ± 1.3 L/min) by 0.496 L/min leading to a Qp:Qs ratio of 1.09 (P = .007). After 6 months, echocardiography revealed no changes in RV diameter (42.96 ± 6.95 mm vs 43.81 ± 7.67 mm; P = .62) and TAPSE (17.13 ± 3.33 mm vs 17.36 ± 3.24 mm; P = .48).

CONCLUSION

Our data show that the MitraClip procedure does not induce a relevant interatrial shunt or right ventricular overload. In fact, future studies will have to show whether the IASD may even be beneficial in selected patient populations by left atrial volume and pressure relief.

Pulmonary haemodynamic effects of interatrial shunt in heart failure with preserved ejection fraction: a preclinical study

AIMS

The aim of this study was to evaluate the effect of the creation of a left-to-right interatrial shunt on pulmonary haemodynamics in rats with heart failure with preserved ejection fraction (HFPEF).

METHODS AND RESULTS

An interatrial communication (IAC) was created in 11 healthy rats (Lewis rats) and 11 rats which developed HFPEF (36-week-old spontaneously hypertensive rats [SHR]). Effects of the interatrial shunt were compared to 11 sham-operated Lewis and 11 sham-operated SHR. At 45 days post shunt, strain effect was observed in diastolic function (E/A ratio, p<0.001; isovolumetric relaxation time, p<0.001), left atrial volume (p=0.005) and pulmonary wall shear rate (WSR) (p=0.02) measured by Doppler echo. At sacrifice of the animals (60 days), a strain effect was also noted in elastin density (p=0.003) and eNOS protein expression (p=0.001). Interatrial shunt creation resulted in (i) an increase in pulmonary WSR (p=0.04) and a decrease in left atrial volume (p<0.001), (ii) an increase in elastin density (p<0.005), and (iii) an increase in eNOS protein expression (p=0.03).

CONCLUSIONS

Creation of a left-to-right atrial shunt in rats with HFPEF was effective in improving pulmonary haemodynamics. In addition, this study provides preliminary evidence of the potential risk of right volume overload and pulmonary hypertension due to atrial shunting.

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.

Therapeutic approaches in heart failure with preserved ejection fraction: past, present, and future

In contrast to the wealth of proven therapies for heart failure with reduced ejection fraction (HFrEF), therapeutic efforts in the past have failed to improve outcomes in heart failure with preserved ejection fraction (HFpEF). Moreover, to this day, diagnosis of HFpEF remains controversial. However, there is growing appreciation that HFpEF represents a heterogeneous syndrome with various phenotypes and comorbidities which are hardly to differentiate solely by LVEF and might benefit from individually tailored approaches. These hypotheses are supported by the recently presented PARAGON-HF trial. Although treatment with LCZ696 did not result in a significantly lower rate of total hospitalizations for heart failure and death from cardiovascular causes among HFpEF patients, subanalyses suggest beneficial effects in female patients and those with an LVEF between 45 and 57%. In the future, prospective randomized trials should focus on dedicated, well-defined subgroups based on various information such as clinical characteristics, biomarker levels, and imaging modalities. These could clarify the role of LCZ696 in selected individuals. Furthermore, sodium-glucose cotransporter-2 inhibitors have just proven efficient in HFrEF patients and are currently also studied in large prospective clinical trials enrolling HFpEF patients. In addition, several novel disease-modifying drugs that pursue different strategies such as targeting cardiac inflammation and fibrosis have delivered preliminary optimistic results and are subject of further research. Moreover, innovative device therapies may enhance management of HFpEF, but need prospective adequately powered clinical trials to confirm safety and efficacy regarding clinical outcomes. This review highlights the past, present, and future therapeutic approaches in HFpEF.

Diagnosis and Management of Patients with Heart Failure with Preserved Ejection Fraction (HFpEF): Current Perspectives and Recommendations

Heart failure with preserved ejection fraction (HFpEF) is a major global public health problem. Diagnosis of HFpEF is still challenging and built based on the comprehensive echocardiographic analysis. Currently, there are no universally accepted therapies that alter the clinical course of HFpEF. This review attempts to summarize the current advances in the diagnosis of HFpEF and provide future directions of the patients´ management with this very widespread, heterogeneous clinical syndrome.

Prediction of haemodynamics after interatrial shunt for heart failure using the generalized circulatory equilibrium

Aims

Interatrial shunting (IAS) reduces left atrial pressure in patients with heart failure. Several clinical trials reported that IAS improved the New York Heart Association score and exercise capacity. However, its effects on haemodynamics vary depending on shunt size, cardiovascular properties, and stressed blood volume. To maximize the benefit of IAS, quantitative prediction of haemodynamics under IAS in individual patients is essential. The generalized circulatory equilibrium framework determines circulatory equilibrium as the intersection of the cardiac output curve and the venous return surface. By incorporating IAS into the framework, we predict the impact of IAS on haemodynamics.

Methods and results

In seven mongrel dogs, we ligated the left anterior descending artery and created impaired cardiac function with elevated left atrial pressure (baseline: 7.8 ± 1.0 vs. impaired: 11.9 ± 3.2 mmHg). We established extracorporeal left‐to‐right atrial shunting with a centrifugal pump. After recording pre‐IAS haemodynamics, we changed IAS flow stepwise to various levels and measured haemodynamics under IAS. To predict the impact of IAS on haemodynamics, we modelled the fluid mechanics of IAS by Newton's second law and incorporated IAS into the generalized circulatory equilibrium framework. Using pre‐IAS haemodynamic data obtained from the dogs, we predicted the impact of IAS flow on haemodynamics under IAS condition using a set of equations. We compared the predicted haemodynamic data with those measured. The predicted pulmonary flow [r² = 0.88, root mean squared error (RMSE) 11.4 mL/min/kg, P < 0.001), systemic flow (r² = 0.92, RMSE 11.2 mL/min/kg, P < 0.001), right atrial pressure (r² = 0.92, RMSE 0.71 mmHg, P < 0.001), and left atrial pressure (r² = 0.83, RMSE 0.95 mmHg, P < 0.001) matched well with those measured under normal and impaired cardiac function. Using this framework, we further performed a simulation study to examine the haemodynamic benefit of IAS in heart failure with preserved ejection fraction. We simulated the IAS haemodynamics under volume loading and exercise conditions. Volume loading and exercise markedly increased left atrial pressure. IAS size‐dependently attenuated the increase in left atrial pressure in both volume loading and exercise. These results indicate that IAS improves volume and exercise intolerance.

Conclusions

The framework developed in this study quantitatively predicts the haemodynamic impact of IAS. Simulation study elucidates how IAS improve haemodynamics under volume loading and exercise conditions. Quantitative prediction of IAS haemodynamics would contribute to maximizing the benefit of IAS in patients with heart failure.

Transcatheter InterAtrial Shunt Device for the treatment of heart failure: Rationale and design of the pivotal randomized trial to REDUCE Elevated Left Atrial Pressure in Patients with Heart Failure II (REDUCE LAP-HF II)

BACKGROUND

A randomized, sham-controlled trial in patients with heart failure (HF) and left ventricular ejection fraction (LVEF) ≥40% demonstrated reductions in pulmonary capillary wedge pressure (PCWP) with a novel transcatheter InterAtrial Shunt Device (IASD). Whether this hemodynamic effect will translate to an improvement in cardiovascular outcomes and symptoms requires additional study.

STUDY DESIGN AND OBJECTIVES

REDUCE Elevated Left Atrial Pressure in Patients with Heart Failure II (REDUCE LAP HF-II) is a multicenter, prospective, randomized, sham-controlled, blinded trial designed to evaluate the clinical efficacy of the IASD in symptomatic HF and elevated left atrial pressures. Up to 608 HF patients age ≥ 40 years with LVEF ≥40%, PCWP ≥25 mm Hg during supine ergometer exercise, and PCWP ≥5 mm Hg higher than right atrial pressure will be randomized 1:1 to the IASD versus sham control. Key exclusion criteria include hemodynamically significant valvular disease, evidence of pulmonary arterial hypertension, and right heart dysfunction. The primary endpoint is a hierarchical composite, analyzed by the Finkelstein-Schoenfeld methodology, that includes (1) cardiovascular mortality or first nonfatal ischemic stroke through 12 months; (2) total (first plus recurrent) HF hospitalizations or healthcare facility visits for intravenous diuretics up to 24 months, analyzed when the last randomized patient completes 12 months of follow-up; and (3) change in Kansas City Cardiomyopathy Questionnaire overall summary score from baseline to 12 months. Follow-up echocardiography will be performed at 6, 12, and 24 months to evaluate shunt flow and cardiac chamber size/function. Patients will be followed for a total of 5 years after the index procedure.

CONCLUSIONS

REDUCE LAP-HF II is designed to evaluate the clinical efficacy of the IASD device in patients with symptomatic HF with elevated left atrial pressure and LVEF ≥40%.

Reappraisal on pharmacological and mechanical treatments of heart failure

Heart failure (HF) is a highly frequent disorder with considerable morbidity, hospitalization, and mortality; thus, it invariably places pressure on clinical and public health systems in the modern world. There have been notable advances in the definition, diagnosis, and treatment of HF, and newly developed agents and devices have been widely adopted in clinical practice. Here, this review first summarizes the current emerging therapeutic agents, including pharmacotherapy, device-based therapy, and the treatment of some common comorbidities, to improve the prognosis of HF patients. Then, we discuss and point out the commonalities and areas for improvement in current clinical studies of HF. Finally, we highlight the gaps in HF research. We are looking forward to a bright future with reduced morbidity and mortality from HF.

Heart failure with preserved ejection fraction: insights from recent clinical researches

Heart failure (HF) with preserved ejection fraction (HFpEF) accounts for nearly half of the cases of HF and its incidence might be increasing with the aging society. Patients with HFpEF present with significant symptoms, including exercise intolerance, impaired quality of life, and have a poor prognosis as well as frequent hospitalization and increased mortality compared with HF with reduced ejection fraction. The concept of HFpEF is still evolving and may be a virtual complex rather than a real systemic disorder. Thus, beyond solely targeting cardiac abnormalities management strategies need to be extended, such as left ventricular diastolic dysfunction. In this review, we examine new diagnostic algorithms, pathophysiology, current management status, and ongoing trials based on heterogeneous pathophysiology and etiology in HFpEF.

TrimetaziDine as a Performance-enhancING drug in heart failure with preserved ejection fraction (DoPING-HFpEF): rationale and design of a placebo-controlled cross-over intervention study

BACKGROUND

Currently, no specific treatment exists for heart failure with preserved ejection fraction (HFpEF). Left ventricular (LV) relaxation during diastole is a highly energy-demanding process, while energy homeostasis is known to be compromised in HFpEF. We hypothesise that trimetazidine - a fatty acid β‑oxidation inhibitor - improves LV diastolic function in HFpEF, by altering myocardial substrate use and improving the myocardial energy status.

OBJECTIVES

To assess whether trimetazidine improves LV diastolic function by improving myocardial energy metabolism in HFpEF.

METHODS

The DoPING-HFpEF trial is a randomised, double-blind, placebo-controlled cross-over intervention trial comparing the efficacy of trimetazidine and placebo in 25 patients with stable HFpEF. The main inclusion criteria are: New York Heart Association functional class II to IV, LV ejection fraction ≥50%, and evidence of LV diastolic dysfunction. Patients are treated with one 20-mg trimetazidine tablet or placebo thrice daily (twice daily in the case of moderate renal dysfunction) for two periods of 3 months separated by a 2-week washout period. The primary endpoint is the change in pulmonary capillary wedge pressure during different intensities of exercise measured by right heart catheterisation. Our key secondary endpoint is the myocardial phosphocreatine (PCr)/ATP ratio measured by phosphorus-31 magnetic resonance spectroscopy and its relation to the primary endpoint. Exploratory endpoints are 6‑min walk distance, N-terminal pro-brain natriuretic peptide levels, and quality of life.

CONCLUSION

The DoPING-HFpEF is a phase-II trial that evaluates the effect of trimetazidine, a metabolic modulator, on diastolic function and myocardial energy status in HFpEF. [EU Clinical Trial Register: 2018-002170-52; NTR registration: NL7830].

Management of heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction is a highly heterogenous disease. There is emerging evidence that treatment should be tailored to the individual’s associated comorbidities

No current algorithms exist for the management of heart failure with preserved ejection fraction. Conventional therapies used in heart failure with reduced ejection fraction are yet to show a mortality benefit

Key treatment objectives include control of hypertension and fluid balance

Common comorbidities include coronary artery disease, atrial fibrillation, obesity, diabetes, renal impairment and pulmonary hypertension. These comorbidities should be considered in all patients and treatment optimised

Hemodynamic assessment in heart failure

Hemodynamics play a central role in the pathophysiology of heart failure (HF), yet their proper assessment and optimization remains challenging. Heart failure is defined as the inability of the heart to deliver adequate perfusion (cardiac output) to the body at rest or exercise, or to require an elevation in cardiac filling pressures in order to do this. This bedrock definition is important because it relies on measurable quantities (filling pressures and output) that are readily assessed in the cardiac catheterization laboratory. Here we present three cases to illustrate how better understanding of the determinants of cardiac output and stroke volume: preload, afterload, contractility, and lusitropy, as well as the determinants of congestion (high filling pressures) may be used to guide optimization of hemodynamic status. The goal is that the readers will be able to think more critically when evaluating the hemodynamics of their patient in HF and recognize the complex interplay that determines the complex balance between cardiac ejection and filling capabilities, and how this alters symptoms and outcomes for patients with HF. KEY POINTS: Careful assessment of hemodynamics in the catheterization laboratory allows for actionable insight to a patient's volume status, cardiac function and can help prognosticate outcomes. Exercise hemodynamics in heart failure is a powerful tool to better understand the cause of symptoms and predict outcomes. Clinicians should aim to decrease biventricular filling pressures to normal values to improve morbidity and reduce risk for readmission. In patients with heart failure and reduced ejection fraction, clinicians should aim to decrease afterload as much as can be tolerated by the renal function and patient's symptoms. Low cardiac output can often be improved by optimizing preload and afterload rather than initiating inotropes, which should be reserved until needed. In advanced heart failure, the right heart function becomes a key determinant of symptoms and outcomes.

Interatrial Shunting for Treating Acute and Chronic Left Heart Failure

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

Heart failure with preserved ejection fraction: New approaches to diagnosis and management

The majority of older patients who develop heart failure (HF), particularly older women, have a preserved left ventricular ejection fraction (HFpEF). Patients with HFpEF have severe symptoms of exercise intolerance, poor quality-of-life, frequent hospitalizations, and increased mortality. The prevalence of HFpEF is increasing and its prognosis is worsening. However, despite its importance, our understanding of the pathophysiology of HFpEF is incomplete, and drug development has proved immensely challenging. Currently, there are no universally accepted therapies that alter the clinical course of HFpEF. Originally viewed as a disorder due solely to abnormalities in left ventricular (LV) diastolic function, our understanding has evolved such that HFpEF is now understood as a systemic syndrome, involving multiple organ systems, likely triggered by inflammation and with an important contribution of aging, lifestyle factors, genetic predisposition, and multiple-comorbidities, features that are typical of a geriatric syndrome. HFpEF is usually progressive due to complex mechanisms of systemic and cardiac adaptation that vary over time, particularly with aging. In this review, we examine evolving data regarding HFpEF that may help explain past challenges and provide future directions to care patients with this highly prevalent, heterogeneous clinical syndrome.

Assessment of Predictors of Left Atrial Volume Response to a Transcatheter InterAtrial Shunt Device (from the REDUCE LAP-HF Trial)

In patients with heart failure and preserved or mildly reduced ejection fractions (EF ≥40%), implantation of an interatrial shunt device (IASD) resulted in heterogenous changes of the left atrial (LA) volume. Baseline characteristics that correlate with a favorable decrease in LA volume are unknown. We hypothesized that a larger ratio of left to right atrial volume at baseline would correlate strongly with LA volume decongestion following IASD implantation. Reduce Elevated LA Pressure in Patients With Heart Failure was a multicenter study of the safety and feasibility of IASD implantation. Sixty-four patients with EF ≥40% underwent device implantation along with baseline conventional echocardiograms, speckle tracking echocardiography, and resting and exercise hemodynamics. Higher LA compliance (-4.2%, p = 0.048) and right atrial reservoir strain (-0.8%, p = 0.005) were independently associated with a percent decrease in the systolic LA volume index from baseline to 6-months. In conclusion, greater LA volume reduction following IASD implantation is associated with higher baseline compliance of the left atrium and higher reservoir strain of the right atrium.

Relative Impairments in Hemodynamic Exercise Reserve Parameters in Heart Failure With Preserved Ejection Fraction: A Study-Level Pooled Analysis

OBJECTIVES

The aim of this study was to compare the relative impairment in different exercise hemodynamic reserve parameters in patients with heart failure with preserved ejection fraction (HFpEF) and control patients using a study-level meta-analysis.

BACKGROUND

A cardinal manifestation of chronic HFpEF is severely decreased exercise capacity. Developing effective therapies for exercise intolerance in HFpEF requires optimal understanding of the factors underlying exercise intolerance.

METHODS

Data were included from 17 unique cohorts that measured peak oxygen uptake and hemodynamic or echocardiographic parameters during exercise in patients with HFpEF and control subjects in this meta-analysis. Standardized mean differences (SMDs) in the exercise reserve (exercise - resting) measures of hemodynamic or echocardiographic parameters between the HFpEF and control groups were pooled in a random-effects meta-analysis.

RESULTS

The pooled analysis included 910 patients with HFpEF and 476 control subjects. In pooled analysis, patients with HFpEF had significantly lower peak oxygen uptake (SMD: -2.13; 95% confidence interval [CI]: -2.68 to -1.57). Among hemodynamic exercise reserve parameters, the largest impairment was observed in chronotropic response reserve (change in heart rate from rest to peak exercise; SMD: -1.87; 95% CI: -2.44 to -1.29), followed by exaggerated increase in pulmonary capillary wedge pressure with exercise (SMD: 1.78; 95% CI: 1.46 to 2.09). Significant abnormalities were also observed in the arteriovenous oxygen difference reserve and stroke volume reserve between the HFpEF and control groups.

CONCLUSIONS

The most consistent and severe hemodynamic reserve abnormalities observed in patients with HFpEF were impairment in chronotropic reserve and exaggerated increase in pulmonary capillary wedge pressure with exercise. These may be important targets for therapeutic strategies to improve exercise tolerance in patients with HFpEF.

20th Annual Feigenbaum Lecture: Echocardiography for Precision Medicine-Digital Biopsy to Deconstruct Biology

Heart failure with preserved ejection fraction (HFpEF) is a complex, heterogeneous syndrome in need of improved classification given its high morbidity and mortality and few effective treatment options. HFpEF represents an ideal setting to examine the utility and feasibility of a precision medicine approach. This article (based on the 20th annual Feigenbaum Lecture, presented at the 2019 American Society of Echocardiography Scientific Sessions) describes the utility of echocardiography as a "digital biopsy" and how deep quantitative echocardiographic phenotyping, coupled with machine learning, can be used to identify novel HFpEF phenotypes. The cellular and ultrastructural basis of abnormal speckle-tracking echocardiography- (STE-) based measurements of cardiac mechanics can provide a window into cardiomyocyte calcium homeostasis. STE-based measurements of longitudinal strain can thus inform the extent of myocardial involvement in patients with HFpEF, which may help to determine responsiveness to cardiac-specific HF medications. However, classifying the complex, systemic, multiorgan nature of HFpEF appropriately likely requires more advanced methods. Using unsupervised machine learning, HFpEF can be classified into three distinct phenogroups with differing clinical and echocardiographic characteristics and outcomes: (1) natriuretic peptide deficiency syndrome; (2) extreme cardiometabolic syndrome; and (3) right ventricle-cardio-abdomino-renal syndrome. Each can be probed to determine their biological basis. The goal of improved classification of HFpEF is to match the right patient with the right treatment, with the hope of improving the track record of HFpEF clinical trials. This article emphasizes the central role of echocardiography in advancing precision medicine and illustrates the integration of basic, translational, clinical, and population research in echocardiography with the goal of better understanding the pathobiology of a complex cardiovascular syndrome.

Therapy for heart failure with preserved ejection fraction: current status, unique challenges, and future directions

Heart failure (HF) with preserved ejection fraction (HFpEF) is the most common form of HF. Among elderly women, HFpEF comprises more than 80% of incident HF cases. Adverse outcomes-exercise intolerance, poor quality of life, frequent hospitalizations, and reduced survival-approach those of classic HF with reduced EF (HFrEF). However, despite its importance, our understanding of the pathophysiology of HFpEF is incomplete, and despite intensive efforts, optimal therapy remains uncertain, as most trials to date have been negative. This is in stark contrast to management of HFrEF, where dozens of positive trials have established a broad array of effective, guidelines-based therapies that definitively improve a range of clinically meaningful outcomes. In addition to providing an overview of current management status, we examine evolving data that may help explain this paradox, overcome past challenges, provide a roadmap for future success, and that underpin a wave of new trials that will test novel approaches based on these insights.

Left Atrial Function with MRI Enables Prediction of Cardiovascular Events after Myocardial Infarction: Insights from the AIDA STEMI and TATORT NSTEMI Trials

Background The role of left atrial (LA) performance in acute myocardial infarction (AMI) remains controversial. Cardiac MRI myocardial feature tracking (hereafter, MRI-FT) is a method used to quantify myocardial function that enables reliable assessment of atrial function. Purpose To assess the relationship between LA function assessed with MRI-FT and major adverse cardiovascular events (MACE) after AMI. Materials and Methods This secondary analysis of two prospective multicenter cardiac MRI studies (AIDA STEMI [NCT00712101] and TATORT NSTEMI [NCT01612312]) included 1235 study participants with ST-elevation myocardial infarction (n = 795) or non-ST-elevation myocardial infarction (n = 440) between July 2008 and June 2013. All study participants underwent primary percutaneous coronary intervention. MRI-FT analyses were performed in a core laboratory by researchers blinded to clinical status to determine LA performance using LA reservoir function peak systolic strain (εs), LA conduit strain (εe), and LA booster pump function active strain (εa). The relationship of LA performance to a MACE within 12 months after AMI was evaluated by using Cox proportional hazards models and area under the receiver operating characteristic curve (AUC). Results Study participants with MACE had worse LA performance parameters compared with study participants without MACE (εs = 21.2% vs 16.2%, εe = 8.8% vs 6.9%, εa = 11.8% vs 10%; P < .001 for all). All atrial parameters were strongly associated with MACE (hazard ratio [HR], εs = 0.9, εe = 0.88, εa = 0.89; P < .001 for all). For εs, a cutoff of 18.8% was identified as the only independent atrial parameter with which to predict MACE after accounting for confounders and established prognostic markers in adjusted analysis (HR, 0.95; P = .02). The εs yielded incremental prognostic value above left ventricular ejection fraction, global longitudinal strain, microvascular obstruction, and infarct size (AUC comparisons, P < .04 for all). Conclusion Feature tracking of cardiac MRI to derive left atrial peak reservoir strain provided incremental prognostic value for major adverse cardiovascular events prediction versus established cardiac risk factors after acute myocardial infarction. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Almeida in this issue.

Short-term decrease of left atrial size predicts clinical outcome in patients with severe aortic stenosis undergoing TAVR

OBJECTIVES

We investigated whether transcatheter aortic valve replacement (TAVR) results in a short-term decrease in left atrium (LA) size and whether such decrease may predict patients' clinical outcome.

BACKGROUND

Increased LA size is a hallmark of severe aortic stenosis (AS) and is associated with adverse patients' cardiovascular outcome. Whether TAVR may lead to a decrease in LA size is not known.

METHODS AND RESULTS

Hundred and four patients with severe symptomatic AS and dilated LA undergoing TAVR were enrolled. LA volume was assessed by echocardiography before and shortly after TAVR (median time: 7 days). Composite rate of death and hospitalization for acutely decompensated heart failure (HF) was recorded and clinical status was assessed through NYHA-class evaluation at 12 months median follow-up. After TAVR, 49 patients (47%) demonstrated a decrease in LA volume. Despite a similar baseline NYHA class, patients with decrease in LA size had significant better improvement in clinical status respect to patients with unvaried LA size (NYHA post: 1.2 ± 0.6 vs. 1.8 ± 1.1, p = .001; NYHA reduction: -1.6 ± 0.9 vs. -0.9 ± 1.0, p = .002, respectively). Moreover, these patients had a significantly reduced rate of death or HF-hospitalization (4 vs. 29%, p = .001) and a significantly longer event-free-survival from Kaplan-Meier curves (p = .003). COX regression analysis showed that, among echocardiographic parameters, decrease in LA size was an independent predictor of clinical outcome (HR: 0.149, CI: 0.034-0.654, p = .012).

CONCLUSIONS

The lack of decrease in LA size shortly after TAVR is associated with significantly higher rates of death and HF-hospitalization, as well as with impaired improvement in clinical status during long-term follow-up.

Interatrial Shunt Device for Heart Failure With Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) accounts for approximately half of the current burden of HF, and the prevalence is continuing to rise. In contrast to HF with reduced ejection fraction (HFrEF) there are no clinically effective evidence based therapies for HFpEF. The principal pathophysiologic disorder is an elevation of left atrial pressure, most notable during physical activity, which results from impaired left ventricular diastolic reserve, and increased left atrial stiffness. This review outlines the clinical development of a potential device based therapy for HFpEF, the interatrial shunt device (IASD).

Heart Failure with Preserved Ejection Fraction

Heart failure (HF) is a clinical syndrome of diverse etiologies and can be associated with preserved, reduced, or mid-range ejection fraction (EF). In the community, heart failure with preserved ejection fraction (HFpEF) is emerging as the most common form of HF. There remains considerable uncertainty regarding its pathogenesis, diagnosis, and optimal therapeutic approach. Hypotheses have been advanced to explain the underlying pathophysiology responsible for HFpEF, but to date, no specific therapy based on these hypotheses has been proven to improve outcomes in HFpEF. We provide a clinically focused review of the epidemiology, clinical presentation, diagnostic approach, pathophysiology, and treatment of HFpEF.

[Heart failure with preserved left ventricular ejection fraction]

Heart failure remains the number one diagnosis among patients receiving inpatient treatment in Germany. Heart failure with preserved ejection fraction (HFpEF) needs to be verified by signs and symptoms of HF, echocardiographic parameters as well as cardiac biomarkers. Based on etiological and pathophysiological considerations, a classification into systolic and diastolic heart failure and later heart failure with reduced ejection fraction (HFrEF) and HFpEF was proposed. The inhomogeneous group of patients with HFpEF accounts for half of all heart failure cases in the population. Effective treatment options are limited. This article discusses which verified treatments may help or may even be harmful. A glimpse is taken into the future and those substances that are in advanced stages of clinical trials are described.

Impact of Baseline Hemodynamics on the Effects of a Transcatheter Interatrial Shunt Device in Heart Failure With Preserved Ejection Fraction

Background Interatrial shunt device (IASD) effects have been described in patients with heart failure and ejection fractions (EFs) ≥40%. However, baseline characteristics that correlate with greatest hemodynamic effects are unknown. On the basis of fundamental principles, we hypothesized that larger pressure gradients between left and right atria would yield greater shunt flow and greater hemodynamic effects. Methods and Results REDUCE LAP-HF (Reduce Elevated Left Atrial Pressure in Patients With Heart Failure) was a multicenter study that investigated IASD safety and performance. Sixty-four patients with EF ≥40% underwent device implantation followed by hemodynamic assessments at rest and exercise, including pulmonary capillary wedge pressure (PCWP, surrogate for left atrial pressure) and central venous pressure (CVP). At 6 months, IASD resulted in an average pulmonary-to-systemic blood flow ratio of 1.27 and increased exercise tolerance. The PCWP-CVP gradient (ie, the driving pressure for shunt flow) decreased at peak exercise from 16.8±6.9 to 11.4±5.5 mm Hg, because of increased CVP (17.5±5.4 to 20.3±7.9 mm Hg; P=0.04) and decreased PCWP (34.1±7.6 to 31.6±8.0 mm Hg; P=0.025). Baseline PCWP-CVP gradient during exercise correlated with changes of both PCWP-CVP and PCWP: Δ(PCWP-CVP)=10.0-0.89·(PCWP-CVP)_baseline ( r²=0.56) and ΔPCWP=7.54-0.60·(PCWP-CVP)_baseline ( P=0.001). Hemodynamics of patients with EF ≥50% and those with EF <50% responded similarly to IASD. Conclusions In heart failure patients with EF ≥40%, IASD significantly reduced PCWP and PCWP-CVP at peak exercise. Patients with higher baseline PCWP-CVP gradient had greater reductions in both parameters at follow-up. Results were sustained through 12 months and were independent of whether EF was ≥50% or between 40% and 49%. Additional studies will help further define the baseline hemodynamic predictors of exercise, hemodynamic, and clinical efficacy of the IASD. Clinical Trial Registration URL: https://www.clinicaltrials.gov . Unique identifier: NCT01913613.

Heart failure with mid-range ejection fraction and with preserved ejection fraction

The annual "heart report" published by the German Heart Foundation (Deutsche Herzstiftung) in December 2017 indicates that heart failure (ICD I50) remains the number one diagnosis of in-hospital-treated patients throughout Germany. For some time, the clinical diagnosis of heart failure has been verified by echocardiographic parameters as well as cardiac biomarkers that assist the clinician to rule in or rule out the presence of a failing heart, when used wisely. By introducing the term "heart failure with mid-range ejection fraction" (HFmrEF), the 2016 European Society of Cardiology (ESC) heart failure guidelines established a third heart failure entity, which was not necessarily seen as an improvement by the heart failure community. Nevertheless, half of all patients suffering from heart failure are now classified as having HFmrEF or heart failure with preserved ejection fraction (HFpEF), but the etiology and treatment options differ substantially. To elucidate this issue, the current review aims to highlight the key findings published to date. This should minimize the confusion that may have been generated by the new term "HFmrEF".

[Mechanisms of exercise intolerance in patients with heart failure and preserved ejection fraction. Part I: The role of impairments in the left heart chambers]

During exercise an increase in oxygen delivery to working muscles is achieved through well‑coordinated interaction of many organs and systems: the heart, lungs, blood vessels, skeletal muscles, and the autonomic nervous system. In heart failure with preserved left ventricular ejection fraction, all mechanisms involved in the normal exercise tolerance are impaired. In the first part of this review, the impairments of the left heart chambers are considered ‑ left ventricular diastolic dysfunction, the weakening of the contractile and chronotropic reserves, left atrium dysfunction; the possible ways of their medical correction are also presented.

Treatment of chronic heart failure in the 21st century: A new era of biomedical engineering has come

Chronic heart failure (CHF) is a challenging burden on public health. Therapeutic strategies for CHF have developed rapidly in the past decades from conventional medical therapy, which mainly includes administration of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, beta-blockers, and aldosterone antagonists, to biomedical engineering methods, which include interventional engineering, such as percutaneous balloon mitral valvotomy, percutaneous coronary intervention, catheter ablation, biventricular pacing or cardiac resynchronization therapy (CRT) and CRT-defibrillator use, and implantable cardioverter defibrillator use; mechanical engineering, such as left ventricular assistant device use, internal artery balloon counterpulsation, cardiac support device use, and total artificial heart implantation; surgical engineering, such as coronary artery bypass graft, valve replacement or repair of rheumatic or congenital heart diseases, and heart transplantation (HT); regenerate engineering, which includes gene therapy, stem cell transplantation, and tissue engineering; and rehabilitating engineering, which includes exercise training, low-salt diet, nursing, psychological interventions, health education, and external counterpulsation/enhanced external counterpulsation in the outpatient department. These biomedical engineering therapies have greatly improved the symptoms of CHF and life expectancy. To date, pharmacotherapy, which is based on evidence-based medicine, large-scale, multi-center, randomized controlled clinical trials, is still a major treatment option for CHF; the current interventional and mechanical device engineering treatment for advanced CHF is not enough owing to its individual status. In place of HT or the use of a total artificial heart, stem cell technology and gene therapy in regenerate engineering for CHF are very promising. However, each therapy has its advantages and disadvantages, and it is currently possible to select better therapeutic strategies for patients with CHF according to cost-efficacy analyses of these therapies. Taken together, we think that a new era of biomedical engineering for CHF has begun.

Restrictive atrial communication in right and left heart failure

Heart failure (HF) is usually defined by the dominantly affected heart chamber; therefore, termed right or left HF (RHF or LHF). Pulmonologists understand RHF as a complex syndrome characterized by insufficient delivery of blood from the right ventricle associated with elevated systemic venous pressure at rest or exercise. Cardiologists specify LHF by its clinical functional class and the relation to a reduced (HFrEF), preserved (HFpEF) or mid-range ejection fraction (HFmrEF). Pediatric cardiologist, dealing also with patients with a failing single ventricle, define HF as a condition of insufficient systemic oxygen delivery (DO₂). Certainly, pediatricians do not think of the right and left heart, or even a single ventricle as an isolated, independently acting entity. Because of the importance of cardiac interactions, the creation of a restrictive atrial communication aims at a palliative approach with the goal to diminish the congestive consequences of a dysfunctional ventricle; further to serve as a pop-off valve in order to prevent syncope and cardiovascular collapse. This review covers the background, the particular indications, the techniques and preliminary results achieved following the creation of a restrictive atrial septum defect (rASD) in different pathophysiological settings. Based on the institutional experience, percutaneous trans-catheter perforation of the atrial septum, followed by gradual balloon dilatation can be performed at any age and location worldwide. Medical institutions in low resource countries can make use of such palliating procedures in the setting of right as well as LHF independent of their pharmacological facilities.

Obesity-related heart failure with preserved ejection fraction: new treatment strategies

OBJECTIVES

Obesity has risen in the US and worldwide, and has become a major risk factor for type 2 diabetes mellitus (T2DM), hypertension, cardiovascular disease, and mostly HF with preserved ejection fraction (HFpEF). Also, the prevalence of HF is quite high in the US accounting for 6.6 million adults at present and is projected to reach 8.5 million by the year 2030 and is equally divided between HFpEF and heart failure reduced ejection fraction (HFrEF). Patients with HFpEF are resistant to treatment with drugs usually used for the treatment of HFrEF, but the reasons for this resistance are not clearly known.

METHODS

In order to get a better perspective on the current status of the underlying pathophysiology and treatment of patients with HFpEF, a Medline search of the English language literature was conducted between 2015 and 2018 using the terms obesity, HFpEF, diabetes, treatment, SGLT2 inhibitors, and neprilysin inhibitors and 24 pertinent papers were selected.

RESULTS

The review of these papers revealed that patients with HFpEF have expanded plasma volume, restricted left ventricular distension with increased end-diastolic volume and depressed natriuretic peptide levels. In this respect, drugs that cause increased diuresis and natriuresis should a reasonable choice to treat these patients. The recently FDA approved sodium-glucose cotransporter-2 (SGLT2) inhibitors for the treatment of T2DM, are a good choice, for the treatment of HFpEF, since they cause osmotic diuresis from glucose excretion and increase salt and water excretion and decrease plasma volume. In addition, they produce loss of calories leading to weight and blood pressure reduction and have shown to prevent the new onset HFpEF and decrease hospitalizations and death from this disease.

CONCLUSION

The results of this analysis has shown that HFpEF has different pathophysiology from HFrEF and is difficult to treat. Drugs that block renal tubular glucose reabsorption and cause osmotic diuresis and natriuresis could be a good choice to treat patients with HFpEF alone or in combination with diuretics and other drugs.