New strategies for heart failure with preserved ejection fraction: the importance of targeted therapies for heart failure phenotypes

Heterogeneous responses of systolic and diastolic left ventricular function to exercise in patients with heart failure and preserved ejection fraction

Aims

This study aimed to evaluate ventricular diastolic properties using three‐dimensional echocardiography and tissue Doppler imaging at rest and during exercise in heart failure with preserved ejection fraction (HFpEF) patients with borderline evidence of diastolic dysfunction at rest.

Methods and results

Results obtained from 52 HFpEF patients (left ventricular ejection fraction ≥ 50%) identified on the basis of heart failure symptoms and E/E′ values between 8 and 15 were compared with those obtained in 26 control patients with no evidence of cardiovascular disease. Mitral flow patterns, tissue Doppler imaging, and volume analysis obtained by three‐dimensional echocardiography were performed at rest and during bicycle exercise. Diastolic compliance was indexed by the E/E′ ratio and left ventricular end‐diastolic volume [(E/E′)/EDV]. There were no significant differences in end‐diastolic volume (EDV), stroke volume (SV), or ejection fraction at rest between groups. In 27 of the 52 patients, E/E′ increased during exercise (11.2 ± 3.7 to 16.8 ± 10.5), driven by a failure to augment early diastole (E′). This correlated with a fall in SV and was associated with an increase in the diastolic index (E/E′)/EDV as a measure for LV stiffness (0.122 ± 0.038 to 0.217 ± 0.14/mL), indicating that impaired diastolic reserve (designated PEF‐I_DR) contributed to exercise intolerance. Of the 52 patients, 25 showed no changes in E/E′ during exercise associated with a significant rise in SV and cardiac output, still inappropriate compared with controls. Despite disturbed early diastole (E′), a blunted increase in estimated systolic LV elastance indicated that impaired systolic reserve and chronotropic incompetence rather than primarily diastolic disturbances contributed to exercise intolerance in this group (designated PEF).

Conclusion

Three‐dimensional stress echocardiography may allow non‐invasive analysis of changes in cardiac output that can differentiate HFpEF patients with an inappropriate increase or a fall in SV during exercise. Impaired systolic or diastolic reserve can contribute to these haemodynamic abnormalities, which may arise from different underlying pathophysiologic mechanisms.

Ergospirometry and echocardiography in early stage of heart failure with preserved ejection fraction and in healthy individuals

Background

Heart failure with preserved ejection fraction is a syndrome characterized by changes in diastolic function; it is more prevalent among the elderly, women, and individuals with systemic hypertension (SH) and diabetes mellitus. However, in its early stages, there are no signs of congestion and it is identified in tests by adverse remodeling, decreased exercise capacity and diastolic dysfunction.

Objective

To compare doppler, echocardiographic (Echo), and cardiopulmonary exercise test (CPET) variables - ergospirometry variables - between two population samples: one of individuals in the early stage of this syndrome, and the other of healthy individuals.

Methods

Twenty eight outpatients diagnosed with heart failure according to Framingham’s criteria, ejection fraction > 50% and diastolic dysfunction according to the european society of cardiology (ESC), and 24 healthy individuals underwent Echo and CPET.

Results

The group of patients showed indexed atrial volume and left ventricular mass as well as E/E’ and ILAV/A´ ratios significantly higher, in addition to a significant reduction in peak oxygen consumption and increased VE/VCO₂ slope, even having similar left ventricular sizes in comparison to those of the sample of healthy individuals.

Conclusion

There are significant differences between the structural and functional variables analyzed by Echo and CPET when comparing two population samples: one of patients in the early stage of heart failure with ejection fraction greater than or equal to 50% and another of healthy individuals.

Wild-type transthyretin amyloidosis as a cause of heart failure with preserved ejection fraction

AIMS

Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous clinical syndrome with multiple underlying causes. Wild-type transthyretin (TTR) amyloidosis (ATTRwt) is an underdiagnosed cause of HFpEF that might benefit from new specific treatments. ATTRwt can be diagnosed non-invasively by (99m)Tc-3,3-diphosphono-1,2-propanodicarboxylic acid ((99m)Tc-DPD) scintigraphy. We sought to determine the prevalence of ATTRwt among elderly patients admitted due to HFpEF.

METHODS AND RESULTS

We prospectively screened all consecutive patients ≥60 years old admitted due to HFpEF [left ventricular (LV) ejection fraction ≥50%] with LV hypertrophy (≥12 mm). All eligible patients were offered a (99m)Tc-DPD scintigraphy. The study included 120 HFpEF patients (59% women, 82 ± 8 years). A total of 16 patients (13.3%; 95% confidence interval: 7.2-19.5) showed a moderate-to-severe uptake on the (99m)Tc-DPD scintigraphy. All patients with a positive scan underwent genetic testing of the TTR gene, and no mutations were found. An endomyocardial biopsy was performed in four patients, confirming ATTRwt in all cases. There were no differences in age, gender, hypertension, diabetes, coronary artery disease, or atrial fibrillation between ATTRwt patients and patients with other HFpEF forms. Although patients with ATTRwt exhibited higher median N-terminal pro-brain natriuretic peptide (6467 vs. 3173 pg/L; P = 0.019), median troponin I (0.135 vs. 0.025 µg/L; P < 0.001), mean LV maximal wall thickness (17 ± 3.4 vs. 14 ± 2.5 mm; P = 0.001), rate of pericardial effusion (44 vs. 19%; P = 0.047), and rate of pacemakers (44 vs. 12%; P = 0.004), clinical overlap between ATTRwt and other HFpEF forms was high.

CONCLUSION

ATTRwt is an underdiagnosed disease that accounts for a significant number (13%) of HFpEF cases. The effect of emerging TTR-modifying drugs should be evaluated in these patients.

Can emergency physicians diagnose and correctly classify diastolic dysfunction using bedside echocardiography?

OBJECTIVES

The goal of this study was to determine if emergency physicians (EPs) can correctly perform a bedside diastology examination (DE) and correctly grade the level of diastolic function with minimal additional training in echocardiography beyond what is learned in residency. We hypothesize that EPs will be accurate at detecting and grading diastolic dysfunction (DD) when compared to a criterion standard interpretation by a cardiologist.

METHODS

We conducted a prospective, observational study on a convenience sample of adult patients who presented to an urban emergency department with a chief concern of dyspnea. All patients had a bedside echocardiogram, including a DE, performed by an EP-sonographer who had 3 hours of didactic and hands-on echocardiography training with a cardiologist. The DE was interpreted as normal, grade 1 to 3 if DD was present, or indeterminate, all based on predefined criteria. This interpretation was compared to that of a cardiologist who was blinded to the EPs' interpretations.

RESULTS

We enrolled 62 patients; 52% had DD. Using the cardiology interpretation as the criterion standard, the sensitivity and specificity of the EP-performed DE to identify clinically significant diastolic function were 92% (95% confidence interval [CI], 60-100) and 69% (95% CI, 50-83), respectively. Agreement between EPs and cardiology on grade of DD was assessed using κ and weighted κ: κ = 0.44 (95% CI, 0.29-0.59) and weighted κ = 0.52 (95% CI, 0.38-0.67). Overall, EPs rated 27% of DEs as indeterminate, compared with only 15% by cardiology. For DEs where both EPs and cardiology attempted an interpretation (indeterminates excluded) κ = 0.45 (95% CI, 0.26 to 0.65) and weighted κ = 0.54 (95% CI, 0.36-0.72).

CONCLUSION

After limited diastology-specific training, EPs are able to accurately identify clinically significant DD. However, correct grading of DD, when compared to a cardiologist, was only moderate, at best. Our results suggest that further training is necessary for EPs to achieve expertise in grading DD.

The (dys)functional extracellular matrix

The extracellular matrix (ECM) is a major component of the biomechanical environment with which cells interact, and it plays important roles in both normal development and disease progression. Mechanical and biochemical factors alter the biomechanical properties of tissues by driving cellular remodeling of the ECM. This review provides an overview of the structural, compositional, and mechanical properties of the ECM that instruct cell behaviors. Case studies are reviewed that highlight mechanotransduction in the context of two distinct tissues: tendons and the heart. Although these two tissues demonstrate differences in relative cell-ECM composition and mechanical environment, they share similar mechanisms underlying ECM dysfunction and cell mechanotransduction. Together, these topics provide a framework for a fundamental understanding of the ECM and how it may vary across normal and diseased tissues in response to mechanical and biochemical cues. This article is part of a Special Issue entitled: Mechanobiology.

Gaps in the Heart Failure Guidelines

There are still many aspects of heart failure care for which gaps remain in the evidence base, resulting in gaps in the guidelines. We aim to highlight these guideline gaps including areas that warrant further research and other areas where new data are forthcoming.

Ischemic stroke and heart failure: facts and numbers

Heart failure (HF) is pandemic in the modern society. Comorbidities of HF come increasingly to the fore in today's patient presentation and demand multidisciplinary treatment concepts. Ischemic stroke is a major comorbidity in HF patients and frequently contributes to the adverse outcome and functional dependency. Patients with HF are two‐fold to three‐fold more likely to suffer an ischemic stroke, have more than two times higher mortality and show worse functional outcome after stroke compared with non‐HF subjects. The risk of recurrent stroke is about two‐fold elevated in patients with HF. The risk of stroke increased with time duration of HF from 18 per 100 cases in the first year of HF to 47 per 1000 patients within the next 4‐5 years. Moreover, so called ‘silent’ strokes (clinically asymptomatic brain lesions) are two to four times more likely in HF patients. In turn, 10–24% of stroke patients have HF. Specific characteristics of the interaction between ischemic stroke and HF have been uncovered in recent years. However, gaps in present knowledge need to be addressed in future studies. What are the detailed pathophysiologic links beyond atrial fibrillation, stroke patterns, and time courses in the interaction? What implication has HF with preserved versus reduced ejection fraction? Does treatment of HF prevents ischemic stroke or reduces stroke‐related sequelae? This editorial provides a condensed overview on current insights and presents facts and numbers on the interaction between heart failure and ischemic stroke.

[New therapy concepts for heart failure with preserved ejection fraction]

The management of patients with heart failure and preserved ejection fraction (HFpEF) remains challenging and requires an accurate diagnosis. Although currently no convincing therapy that can prolong survival in patients with HFpEF has been established, treatment of fluid retention, heart rate and control of comorbidities are important cornerstones to improve the quality of life and symptoms. In recent years many new therapy targets have been tested for development of successful interventional strategies for HFpEF. Insights into new mechanisms of HFpEF have shown that heart failure is associated with dysregulation of the nitric oxide-cyclic guanosine monophosphate-protein kinase (NO-cGMP-PK) pathway. Two new drugs are currently under investigation to test whether this pathway can be significantly improved by either the neprilysin inhibitor LCZ 696 due to an increase in natriuretic peptides or by the soluble guanylate cyclase stimulator vericiguat, which is also able to increase cGMP. In addition, several preclinical or early phase studies which are currently investigating new mechanisms for matrix, intracellular calcium and energy regulation including the role of microRNAs and new devices are presented and discussed.

Noncardiac comorbidities in heart failure with preserved ejection fraction - commonly ignored fact

It has been well described that many patients with heart failure (HF) have a normal left ventricular ejection fraction. This entity has been termed "heart failure with preserved ejection fraction (HFPEF)". Significant advances have been made in understanding the clinical characteristics of HFPEF over the past 2 decades on the basis of large HF registries and randomized clinical trials. However, most multicenter clinical trials that investigated medical therapies in HFPEF have yielded disappointing results. HFPEF being a clinical syndrome involving multiple organ systems may be a potential explanation for treatment failure. In this review we discuss the prevalence of noncardiac comorbidities in HFPEF patients as well as their effect on the prognosis of HFPEF.

Heart failure with preserved ejection fraction: refocusing on diastole

Heart failure (HF) with preserved ejection fraction (HFpEF) is a clinical syndrome of exercise intolerance and/or congestion, in the presence of a left ventricular (LV) ejection fraction within the normal limits (i.e. LVEF>50%). Determining the presence of impaired LV relaxation and/or filling (diastolic dysfunction) in HFpEF is needed to pragmatically to distinguish it from other cardiac and non-cardiac conditions where symptoms are not due to HF. There are multiple mechanisms for diastolic dysfunction ranging from structural abnormalities to functional derangements in HFpEF yet tailored therapies are lacking. Treatments proven effective in HF with systolic dysfunction have failed to show significant benefit in patients with HFpEF, which prognosis remains poor. This review will discuss the challenges inherent to the use of diagnostic criteria for HFpEF, differential diagnosis, prognostic evaluation, and treatment, highlighting the need for more research in this field.

Gaps in the Heart Failure Guidelines

There are still many aspects of heart failure care for which gaps remain in the evidence base, resulting in gaps in the guidelines. We aim to highlight these guideline gaps including areas that warrant further research and other areas where new data are forthcoming.