Diastolic pressure-volume quotient (DPVQ) as a novel echocardiographic index for estimation of LV stiffness in HFpEF

Computational investigation of the role of ventricular remodelling in HFpEF: The key to phenotype dissection

Recent clinical studies have reported that heart failure with preserved ejection fraction (HFpEF) can be divided into two phenotypes based on the range of ejection fraction (EF), namely HFpEF with higher EF and HFpEF with lower EF. These phenotypes exhibit distinct left ventricle (LV) remodelling patterns and dynamics. However, the influence of LV remodelling on various LV functional indices and the underlying mechanics for these two phenotypes are not well understood. To address these issues, this study employs a coupled finite element analysis (FEA) framework to analyse the impact of various ventricular remodelling patterns, specifically concentric remodelling (CR), concentric hypertrophy (CH), and eccentric hypertrophy (EH), with and without LV wall thickening on LV functional indices. Further, the geometries with a moderate level of remodelling from each pattern are subjected to fibre stiffening and contractile impairment to examine their effect in replicating the different features of HFpEF. The results show that with severe CR, LV could exhibit the characteristics of HFpEF with higher EF, as observed in recent clinical studies. Controlled fibre stiffening can simultaneously increase the end-diastolic pressure (EDP) and reduce the peak longitudinal strain (ell) without significant reduction in EF, facilitating the moderate CR geometries to fit into this phenotype. Similarly, fibre stiffening can assist the CH and 'EH with wall thickening' cases to replicate HFpEF with lower EF. These findings suggest that potential treatment for these two phenotypes should target the bio-origins of their distinct ventricular remodelling patterns and the extent of myocardial stiffening.

Computational modeling of heart failure in microgravity transitions

The space tourism industry is growing due to advances in rocket technology. Privatised space travel exposes non-professional astronauts with health profiles comprising underlying conditions to microgravity. Prior research has typically focused on the effects of microgravity on human physiology in healthy astronauts, and little is known how the effects of microgravity may play out in the pathophysiology of underlying medical conditions, such as heart failure. This study used an established, controlled lumped mathematical model of the cardiopulmonary system to simulate the effects of entry into microgravity in the setting of heart failure with both, reduced and preserved ejection fraction. We find that exposure to microgravity eventuates an increased cardiac output, and in patients with heart failure there is an unwanted increase in left atrial pressure, indicating an elevated risk for development of pulmonary oedema. This model gives insight into the risks of space flight for people with heart failure, and the impact this may have on mission success in space tourism.

Comparative analysis of ventricular stiffness across species

Investigating ventricular diastolic properties is crucial for understanding the physiological cardiac functions in organisms and unraveling the pathological mechanisms of cardiovascular disorders. Ventricular stiffness, a fundamental parameter that defines ventricular diastolic functions in chordates, is typically analyzed using the end-diastolic pressure-volume relationship (EDPVR). However, comparing ventricular stiffness accurately across chambers of varying maximum volume capacities has been a long-standing challenge. As one of the solutions to this problem, we propose calculating a relative ventricular stiffness index by applying an exponential approximation formula to the EDPVR plot data of the relationship between ventricular pressure and values of normalized ventricular volume by the ventricular weight. This article reviews the potential, utility, and limitations of using normalized EDPVR analysis in recent studies. Herein, we measured and ranked ventricular stiffness in differently sized and shaped chambers using ex vivo ventricular pressure-volume analysis data from four animals: Wistar rats, red-eared slider turtles, masu salmon, and cherry salmon. Furthermore, we have discussed the mechanical effects of intracellular and extracellular viscoelastic components, Titin (Connectin) filaments, collagens, physiological sarcomere length, and other factors that govern ventricular stiffness. Our review provides insights into the comparison of ventricular stiffness in different-sized ventricles between heterologous and homologous species, including non-model organisms.

Predicting readmission for heart failure patients by echocardiographic assessment of elevated left atrial pressure

BACKGROUND

Pathophysiologically, an elevated left ventricular (LV) filling pressure is the major reason for heart failure (HF) readmission. The 2016 American Society of Echocardiography (ASE)/European Association of Cardiovascular Imaging (EACVI) guidelines provide a simplified algorithm for the echocardiographic assessment of LV filling pressure; however, this algorithm is yet to be sufficiently validated.

MATERIALS AND METHODS

We retrospectively studied 139 consecutive patients with acute decompensated HF. High estimated left atrial pressure (eLAP) was defined according to the 2016 ASE/EACVI guidelines. Univariate and multivariate logistic regression analyses were performed to identify significant risk factors for HF readmission within one year of discharge.

RESULTS

Across the study cohort, 68 patients (49%) did not have a high eLAP, 32 (23%) had an indeterminate eLAP, and 39 (28%) had a high eLAP. The number of HF readmission events within one year in the without high eLAP, indeterminate, and high eLAP groups were 4 (7.5%), 5 (18.5%), and 10 (33.3%), respectively. The HF readmission rate was significantly higher in patients with high eLAP than in those without high eLAP. Multivariate analysis revealed high eLAP (odds ratio, 5.924; 95% confidence interval, 1.664-21.087; P = 0.006) as a significant risk factor for HF readmission within one year. Furthermore, the exploratory analysis of the two-year outcomes revealed a similar finding: patients with high eLAP had a significantly higher rate of readmission for HF.

CONCLUSIONS

The present study demonstrated that echocardiographic assessment of elevated LAP based on the 2016 ASE/EACVI guidelines is clinically valid for predicting readmission in patients with HF.

Unraveling the role of resistin, retinol-binding protein 4 and adiponectin produced by epicardial adipose tissue in cardiac structure and function: evidence of a paracrine effect

PURPOSE

Adipokines produced by adipose tissue have been found to be involved in the pathophysiology of metabolic and cardiovascular diseases. We aimed to investigate the relationships of resistin, retinol-binding protein 4 (RBP4) and adiponectin produced by epicardial adipose tissue with coronary artery disease (CAD) and cardiac structure and function.

METHODS

Forty-one non-diabetic males scheduled for cardiothoracic surgery were examined. Anthropometric measurements, echocardiography, coronary angiography, and blood analysis were performed preoperatively. We measured the serum levels of resistin, RBP4, and adiponectin and their mRNA expression in thoracic subcutaneous adipose tissue and two epicardial adipose tissue samples, one close to left anterior descending artery (LAD) (resistin-LAD, RBP4-LAD, adiponectin-LAD), and another close to the right coronary artery (RCA) (resistin-RCA, RBP4-RCA, adiponectin-RCA).

RESULTS

Left ventricular (LV) ejection fraction correlated negatively with adiponectin-LAD (rho =  - 0.390, p = 0.025). The ratio of early to late diastolic transmitral flow velocity, as an index of LV diastolic function, correlated negatively with resistin-LAD (rho =  - 0.529, p = 0.024) and RBP4-LAD (rho =  - 0.458, p = 0.049). There was no difference in epicardial adipose tissue mRNA expression of resistin, RBP4, and adiponectin between individuals with CAD and those without CAD. When we compared the individuals with CAD in the LAD with those without CAD in the LAD, there was no difference in resistin-LAD, RBP4-LAD, and adiponectin-LAD. There was no difference in resistin-RCA, RBP4-RCA, and adiponectin-RCA between the individuals with CAD in the RCA and those without CAD in the RCA.

CONCLUSION

Elevation of epicardial adipose tissue mRNA expression of adiponectin was associated with LV systolic dysfunction, while that of both resistin and RBP4 was linked to LV diastolic dysfunction.

In vitro benchtop mock circulatory loop for heart failure with preserved ejection fraction emulation

In this work, a novel mock circulatory loop (MCL) is presented that is capable of simulating both healthy cardiac function and Heart Failure with preserved Ejection Fraction (HFpEF). This MCL differs from others presented in the literature as it features two independently actuated heart chambers, representing the left atrium and the left ventricle. This is an important improvement over other designs as it allows for potential HFpEF treatments to be examined, not just in relation to their effect on the left ventricle but also on the left atrium. The aim of this work was to show that novel MCL designs could be developed to allow for testing of new mechanical circulatory support devices for the treatment of HFpEF. Two loop configurations are presented, one featuring hard PVC cylindrical chambers and one that features soft silicone chambers which are anatomically analogous to the native heart. We show that both MCLs are capable of simulating the onset of HFpEF with a sustained increase in diastolic pressure of 62.03% and a sustained decrease in end diastolic volume (EDV) of 14.24%.

Acute Left Atrial Response to Different Eccentric Resistance Exercise Loads in Patients with Heart Failure with Middle Range Ejection Fraction: A Pilot Study

In this study, we aimed to assess acute changes occurring on atrial function following single bouts of eccentric resistance exercise (ECC-RE) performed at two different loads. Twenty-five patients with chronic heart failure with middle range ejection fraction (HFmrEF) participated in three experimental sessions in a randomized order and on separate days: two sessions of ECC RE at 20% (ECC-20) of one-repetition maximum (1-RM) and 50% (ECC-50) 1-RM, and one session of control, without exercise. Each session lasted three minutes. Before and immediately after the sessions, patients underwent echocardiography and blood pressure and heart rate measurement. Peak atrial longitudinal strain (PALS) and peak atrial contractile strain (PACS) significantly increased after both ECC-20 (+16.3%) and ECC-50 (+18.1%) compared to control (between sessions p = 0.022). Peak atrial contractile strain (PACS) significantly increased after ECC-50 (+28.4%) compared to ECC-20 (+17.0%) and control (between sessions p = 0.034). The ratio of transmitral and annular velocities (E/E') increased significantly after ECC-20 (+10.4%) and ECC-50 (+19.0%) compared to control (between groups p = 0.003). EF, left ventricular longitudinal strain, and stroke volume did not change after ECC-RE sessions compared to control. Cardiac output increased significantly after ECC-20 and ECC-50 compared to control, (between groups p = 0.025). In conclusion, both ECC-RE sessions were well tolerated, and LA functional reserve was properly mobilized in response to ECC-RE in patients with HFmrEF. Cardiac output increased at the cost of an increased LV filling pressure, but no detrimental changes of LV function occurred.

Diastolic Dysfunction With Preserved Ejection Fraction After the Fontan Procedure

Background Heart failure phenotyping in single-ventricle Fontan patients is challenging, particularly in patients with normal ejection fraction (EF). The objective of this study was to identify Fontan patients with abnormal diastolic function, who are high risk for heart failure with preserved ejection fraction (HFpEF), and characterize their cardiac mechanics, exercise function, and functional health status. Methods and Results Data were obtained from the Pediatric Heart Network Fontan Cross-sectional Study database. EF was considered abnormal if <50%. Diastolic function was defined as abnormal if the diastolic pressure:volume quotient (lateral E:e'/end-diastolic volume) was >90th percentile (≥0.26 mL-1). Patients were divided into: controls=normal EF and diastolic function; systolic dysfunction (SD) = abnormal EF with normal diastolic function; diastolic dysfunction (DD) = normal EF with abnormal diastolic pressure:volume quotient. Exercise function was quantified as percent predicted peak VO2. Physical Functioning Summary Score (FSS) was reported from the Child Health Questionnaire. A total of 239 patients were included, 177 (74%) control, 36 (15%) SD, and 26 (11%) DD. Median age was 12.2 (5.4) years. Arterial elastance, a measure of arterial stiffness, was higher in DD (3.6±1.1 mm Hg/mL) compared with controls (2.5±0.8 mm Hg/mL), P<0.01. DD patients had lower predicted peak VO2 compared with controls (52% [20] versus 67% [23], P<0.01). Physical FSS was lower in DD (45±13) and SD (44±13) compared with controls (50±7), P<0.01. Conclusions Fontan patients with abnormal diastolic function and normal EF have decreased exercise tolerance, decreased functional health status, and elevated arterial stiffness. Identification of patients at high risk for HFpEF is feasible and should be considered when evaluating Fontan patients.

Central Hemodynamic Adjustments during Post-Exercise Hypotension in Hypertensive Patients with Ischemic Heart Disease: Concurrent Circuit Exercise versus High-Intensity Interval Exercise. A Preliminary Study

Concurrent aerobic plus resistance exercise (RAE) and high-intensity interval exercise (HIIE) are both effective at inducing post-exercise hypotension (PEH) in patients with hypertension. However, central hemodynamic changes associated with PEH in hypertensive subjects with underlying ischemic heart disease (IHD) have been poorly investigated. The study aim was to compare the acute effects produced by these two exercise modalities on left ventricular diastolic function and left atrial function. Twenty untrained male patients with a history of hypertension and IHD under stable pharmacological therapy were enrolled. Each patient underwent three exercise sessions: RAE, HIIE and a control session without exercise, each lasting 45 min. An echocardiography examination was performed before and between 30 min and 40 min from the end of the exercise sessions. Following the exercise sessions, BP values decreased in a similar way in RAE and HIIE and were unchanged after the control session. Compared to pre-session, the ratio between early filling velocity (E) and mitral annulus early diastolic velocity (E’). E/E’ increased after HIIE and remained unchanged after both RAE and control sessions (between-sessions p 0.002). Peak atrial longitudinal strain (PALS) increased slightly after RAE (+1.4 ± 1.1%), decreased after HIIE (−4.6 ± 2.4%) and was unchanged after the control session (between-sessions p 0.03). Peak atrial contraction strain (PACS) was mildly increased after RAE, was reduced after HIIE and was unchanged after the control session. Atrial volume was unchanged after both exercise sessions. Left ventricular and left atrial stiffness increased significantly after HIIE, but remained unchanged after the RAE and control sessions. Stroke volume and cardiac output increased after RAE, decreased after HIIE, and were unchanged after the control session. In conclusion, single session of RAE and HIIE brought about similar PEH in hypertensive subjects with IHD, while they evoked different central hemodynamic adjustments. Given its neutral effects on diastolic and atrial functions, RAE seems more suitable for reducing blood pressure in hypertensive patients with IHD.

Influence of Left Ventricular Function on the "Aortic Regurgitation Index" Proposed for the Hemodynamic Assessment of Postprocedural Aortic Regurgitation

The aortic regurgitation (AR) index, proposed as an objective indicator of postprocedural AR, decreases in proportion to AR severity, besides reportedly providing additional prognostic information. Meanwhile, left ventricular (LV) function has also been considered an essential prognostic factor. This study aimed to clarify whether LV function affected the AR index using cardiac catheterization data.A retrospective study was performed in patients whose LV function was evaluated using a micromanometer-tipped catheter. Patients with grade 2 or higher AR were excluded to explore non-AR factors affecting the AR index value. The AR index was calculated as a ratio of the gradient between the aortic diastolic blood pressure (DBP) and the LV end-diastolic pressure (EDP) to the aortic systolic blood pressure (SBP): AR Index = [ (DBP - LVEDP) / SBP] × 100.A total of 64 patients [age, 62 (interquartile range: 48-70) years; LV ejection fraction, 19% (16%-26%) ] were examined. AR index values ranged from 18.3 to 68.6. Despite having no AR, two patients displayed an AR index < 25, indicating significant AR. Multiple-regression analysis revealed that LV diastolic stiffness (β = -0.750, P < 0.001), LV max dP/dt (β = -0.296, P = 0.006), and heart rate (β = 0.284, P = 0.011) were independent determinants of the AR index value.Patients with impaired LV diastolic function and preserved systolic function had low AR index values. The additional prognostic information of the AR index may be related to LV diastolic function.

The non-invasive assessment of myocardial work by pressure-strain analysis: clinical applications

Pressure–volume (PV) analysis is the most comprehensive way to describe cardiac function, giving insights into cardiac mechanics and energetics. However, PV analysis still remains a highly invasive and time-consuming method, preventing it from integration into clinical practice. Most of the echocardiographic parameters currently used in the clinical routine to characterize left ventricular (LV) systolic function, such as LV ejection fraction and LV global longitudinal strain, do not take the pressure developed within the LV into account and therefore fall too short in describing LV function as a hydraulic pump. Recently, LV pressure-strain analysis has been introduced as a new technique to assess myocardial work in a non-invasive fashion. This new method showed new insights in comparison to invasive measurements and was validated in different cardiac pathologies, e.g., for the detection of coronary artery disease, cardiac resynchronization therapy (CRT)-response prediction, and different forms of heart failure. Non-invasively assessed myocardial work may play a major role in guiding therapies and estimating prognosis. However, its incremental prognostic validity in comparison to common echocardiographic parameters remains unclear. This review aims to provide an overview of pressure-strain analysis, including its current application in the clinical arena, as well as potential fields of exploitation.

The utility of cardiovascular imaging in heart failure with preserved ejection fraction: diagnosis, biological classification and risk stratification

Heart failure with preserved ejection fraction (HFpEF) does not exist as a singular clinical or pathological entity but as a syndrome encompassing a wide range of clinical and biological phenotypes. There is an urgent need to progress from the unsuccessful 'one-size-fits-all' approach to more precise disease classification, in order to develop targeted therapies, personalise risk stratification and guide future research. In this regard, this review discusses the current and emerging roles of cardiovascular imaging for the diagnosis of HFpEF, for distilling HFpEF into distinct disease entities according to underlying pathobiology and for risk stratification.

Clinical Impact of Worsening Renal Function in Elderly Patients with Acute Decompensated Heart Failure

Background and Objectives

The clinical significance of worsening renal function (WRF) in elderly patients with acute decompensated heart failure (ADHF) is not completely understood. We compared the clinical conditions between younger and elderly patients with ADHF after the appearance of WRF to establish its prognostic influence.

Methods

We included 654 consecutive patients (37% women) admitted for ADHF. We divided the patients into four groups according to their age (<80 years, under-80, n=331; ≥80 years, over-80, n=323) and to their WRF statuses (either WRF or non-WRF group). We defined WRF as an increase in serum creatinine level ≥0.3 mg/dL or ≥150% within 48 hours after hospital arrival (under-80, n=62; over-80, n=75). The primary endpoint was a composite of cardiac events within 1 year.

Results

The survival analyses revealed that the WRF group had significantly more cardiac events than the non-WRF group in patients in the over-80 group (log-rank p=0.025), but not in those of the under-80 group (log-rank p=0.50). The patients in the over-80, WRF group presented more significant mean blood pressure (MBP) drops than those in the over-80 non-WRF group (p=0.003). Logistic regression analyses revealed that higher MBP at admission was a significant predictor of WRF.

Conclusions

WRF is a predictor of poor outcomes in elderly patients with ADHF.

Meta-analysis of echocardiographic quantification of left ventricular filling pressure

Aims

The clinical reliability of echocardiographic surrogate markers of left ventricular filling pressures (LVFPs) across different cardiovascular pathologies remains unanswered. The main objective was to evaluate the evidence of how effectively different echocardiographic indices estimate true LVFP.

Methods and results

Design: this is a systematic review and meta‐analysis. Data source: Scopus, PubMed and Embase. Eligibility criteria for selecting studies were those that used echocardiography to predict or estimate pulmonary capillary wedge pressure or left ventricular end‐diastolic pressures. Twenty‐seven studies met criteria. Only eight studies (30%) reported both correlation coefficient and bias between non‐invasive and invasively measured LVFPs. The majority of studies (74%) recorded invasive pulmonary capillary wedge pressure as a surrogate for left ventricular end‐diastolic pressures. The pooled correlation coefficient overall was r = 0.69 [95% confidence interval (CI) 0.63–0.75, P < 0.01]. Evaluation by cohort demonstrated varying association: heart failure with preserved ejection fraction (11 studies, n = 575, r = 0.59, 95% CI 0.53–0.64) and heart failure with reduced ejection fraction (8 studies, n = 381, r = 0.67, 95% CI 0.61–0.72).

Conclusions

Echocardiographic indices show moderate pooled association to invasively measured LVFP; however, this varies widely with disease state. In heart failure with preserved ejection fraction, no single echocardiography‐based metric offers a reliable estimate. In heart failure with reduced ejection fraction, mitral inflow‐derived indices (E/e′, E/A, E/Vp, and EDcT) have reasonable clinical applicability. While an integrated approach of several echocardiographic metrics provides the most promise for estimating LVFP reliably, such strategies need further validation in larger, patient‐specific studies.

How to diagnose heart failure with preserved ejection fraction: the HFA-PEFF diagnostic algorithm: a consensus recommendation from the Heart Failure Association (HFA) of the European Society of Cardiology (ESC)

Making a firm diagnosis of chronic heart failure with preserved ejection fraction (HFpEF) remains a challenge. We recommend a new stepwise diagnostic process, the 'HFA-PEFF diagnostic algorithm'. Step 1 (P=Pre-test assessment) is typically performed in the ambulatory setting and includes assessment for HF symptoms and signs, typical clinical demographics (obesity, hypertension, diabetes mellitus, elderly, atrial fibrillation), and diagnostic laboratory tests, electrocardiogram, and echocardiography. In the absence of overt non-cardiac causes of breathlessness, HFpEF can be suspected if there is a normal left ventricular ejection fraction, no significant heart valve disease or cardiac ischaemia, and at least one typical risk factor. Elevated natriuretic peptides support, but normal levels do not exclude a diagnosis of HFpEF. The second step (E: Echocardiography and Natriuretic Peptide Score) requires comprehensive echocardiography and is typically performed by a cardiologist. Measures include mitral annular early diastolic velocity (e'), left ventricular (LV) filling pressure estimated using E/e', left atrial volume index, LV mass index, LV relative wall thickness, tricuspid regurgitation velocity, LV global longitudinal systolic strain, and serum natriuretic peptide levels. Major (2 points) and Minor (1 point) criteria were defined from these measures. A score ≥5 points implies definite HFpEF; ≤1 point makes HFpEF unlikely. An intermediate score (2-4 points) implies diagnostic uncertainty, in which case Step 3 (F1: Functional testing) is recommended with echocardiographic or invasive haemodynamic exercise stress tests. Step 4 (F2: Final aetiology) is recommended to establish a possible specific cause of HFpEF or alternative explanations. Further research is needed for a better classification of HFpEF.

Pathophysiological role of fatty acid-binding protein 4 in Asian patients with heart failure and preserved ejection fraction

Aims

Systemic metabolic impairment is the key pathophysiology of heart failure (HF) with preserved ejection fraction (HFpEF). Fatty acid‐binding protein 4 (FABP4) is highly expressed in adipocytes and secreted in response to lipolytic signals. We hypothesized that circulating FABP4 levels would be elevated in patients with HFpEF, would correlate with cardiac structural and functional abnormalities, and could predict clinical outcomes.

Methods and results

Serum FABP4 measurements and echocardiography were performed in patients with HFpEF (n = 92) and those with coronary artery disease free of HF (n = 20). Patients were prospectively followed‐up for a composite endpoint of all‐cause mortality or HF hospitalization. Compared with patients with coronary artery disease, those with HFpEF had higher FABP4 levels [12.5 (9.1–21.0) vs. 43.5 (24.6–77.4) ng/mL, P < 0.0001]. FABP4 levels were associated with cardiac remodelling (left ventricular mass index: r = 0.29, P = 0.002; left atrial volume index: r = 0.40, P < 0.0001), left ventricular systolic and diastolic dysfunction (global longitudinal strain: r = −0.24, P = 0.01; E/e′ ratio: r = 0.29, P = 0.002; and N‐terminal pro‐B‐type natriuretic peptide: r = 0.62, P < 0.0001), and right ventricular dysfunction (tricuspid annular plane systolic excursion: r = −0.43, P < 0.0001). During a median follow‐up of 9.1 months, there were 28 primary endpoints in the HFpEF cohort. Event‐free survival was significantly decreased in patients with FABP4 levels ≥43.5 ng/mL than in those with FABP4 levels <43.5 ng/mL (P = 0.003).

Conclusions

Serum FABP4 levels were increased in HFpEF and were associated with cardiac remodelling and dysfunction, and poor outcomes. Thus, FABP4 could be a potential biomarker in the complex pathophysiology of HFpEF.

Novel Echocardiography-Derived Left Ventricular Stiffness Index in Low-Flow Versus Normal-Flow Severe Aortic Stenosis with Preserved Left Ventricular Ejection Fraction

Background Paradoxical low-flow (LF) severe aortic stenosis (AS) with preserved left ventricular ejection fraction (LVEF) may have poorer prognosis than normal-flow (NF) AS, though its pathophysiology remained unclear. In particular, LV stiffness has not been compared between LF vs NF. We used a novel echocardiography-derived index of LV stiffness to compare between these groups. Consecutive patients with medically-managed isolated severe AS (aortic valve area < 1 cm²) and preserved LVEF (>50%) were studied. Echocardiographic LV stiffness index was measured by a method previously validated against cardiac catheterization. We compared LF (stroke volume index, SVI < 35 ml/m²) and NF severe AS. Of the 352 patients, 121 (34%) were LF. Both LF and NF groups had similar demographics, valve areas and indices. Compared to NF, LF severe AS had higher LV stiffness indices (>0.11 ml^-1 OR 3.067, 95% CI 1.825-5.128, p < 0.001). Increased LV stiffness was associated with concentric remodelling and more severe diastolic dysfunction, especially in LF AS. An LV stiffness index of > 0.11 ml^-1 was independently associated with increased mortality, after adjusting for age, clinical and echocardiographic parameters (HR 2.283 95% CI 1.318-3.968, p = 0.003). Non-invasive echocardiographic-derived index of LV stiffness may be important in LF AS. Increased LV stiffness was related to LV concentric remodelling and diastolic dysfunction, and associated with poorer clinical outcomes in medically-managed AS.

How to diagnose heart failure with preserved ejection fraction: the HFA-PEFF diagnostic algorithm: a consensus recommendation from the Heart Failure Association (HFA) of the European Society of Cardiology (ESC)

Making a firm diagnosis of chronic heart failure with preserved ejection fraction (HFpEF) remains a challenge. We recommend a new stepwise diagnostic process, the 'HFA-PEFF diagnostic algorithm'. Step 1 (P=Pre-test assessment) is typically performed in the ambulatory setting and includes assessment for heart failure symptoms and signs, typical clinical demographics (obesity, hypertension, diabetes mellitus, elderly, atrial fibrillation), and diagnostic laboratory tests, electrocardiogram, and echocardiography. In the absence of overt non-cardiac causes of breathlessness, HFpEF can be suspected if there is a normal left ventricular (LV) ejection fraction, no significant heart valve disease or cardiac ischaemia, and at least one typical risk factor. Elevated natriuretic peptides support, but normal levels do not exclude a diagnosis of HFpEF. The second step (E: Echocardiography and Natriuretic Peptide Score) requires comprehensive echocardiography and is typically performed by a cardiologist. Measures include mitral annular early diastolic velocity (e'), LV filling pressure estimated using E/e', left atrial volume index, LV mass index, LV relative wall thickness, tricuspid regurgitation velocity, LV global longitudinal systolic strain, and serum natriuretic peptide levels. Major (2 points) and Minor (1 point) criteria were defined from these measures. A score ≥5 points implies definite HFpEF; ≤1 point makes HFpEF unlikely. An intermediate score (2-4 points) implies diagnostic uncertainty, in which case Step 3 (F₁ : Functional testing) is recommended with echocardiographic or invasive haemodynamic exercise stress tests. Step 4 (F₂ : Final aetiology) is recommended to establish a possible specific cause of HFpEF or alternative explanations. Further research is needed for a better classification of HFpEF.

Impact of medical therapy for cardiovascular disease on left ventricular diastolic properties and remodeling

Background

Left ventricular (LV) remodeling and diastolic properties are affected by both underlying cardiovascular disease/cardiovascular disease risk factors (CVDRFs) and corresponding medication therapy. However, these effects may not be apparent in patients with multiple CVDRFs. We evaluated the effect of medication classes on hemodynamics in a patient cohort with normal LV dimensions and systolic function.

Methods

In 38 participants (61 ± 7 years, 64 ± 9% LV ejection fraction) undergoing coronary angiography, LV pressure measurement and cardiac magnetic resonance imaging was performed. The effects of coronary artery disease (CAD), CVDRFs and their corresponding medication therapy on LV parameters were analyzed considering the number of CAD/CVDRFs and ‘adequacy’ of medication therapy to address each existing condition with specific indication-based medication classes.

Results

Of the patients studied, 68% had CAD, 87% had hypertension, 87% had dyslipidemia, and 45% had diabetes. Neither individual or total number of CAD/CVDRFs were associated with overall differences in LV diastolic parameters. However, those without (n = 20) and with (n = 18) ‘adequate’ medication therapy for underlying CAD/CVDRFs differed in values of LV end diastolic pressure (17 ± 4 vs. 11 ± 5 mm Hg, P < 0.001), wall stress (3.9 ± 1.6 vs. 2.2 ± 1.2 x1000 N/m², P < 0.001), pressure/volume ratio (0.13 ± 0.04 vs. 0.08 ± 0.03 mm Hg/ml, P < 0.01), and mass/volume ratio (0.77 ± 0.20 vs. 0.92 ± 0.24 g/ml, P < 0.05), but not in systolic blood pressure or LV mass index.

Conclusions

Our results suggest an association between the degree of LV diastolic impairment and LV remodeling with the intensity of treatment for CAD/CVDRFs. Comprehensive treatment of all identified CAD/CVDRFs may be an important factor for the preservation of diastolic function.

The Role of Echocardiography in Heart Failure with Preserved Ejection Fraction: What Do We Want from Imaging?

Noninvasive imaging, particularly echocardiography, plays a central role in the evaluation for heart failure with preserved ejection fraction (HFpEF). Echocardiography helps to rule in HFpEF among patients with unexplained dyspnea when the diagnosis is uncertain. In established HFpEF, echocardiography provides important insights into pathophysiology and phenotyping, such as isolated left ventricular diastolic dysfunction, left atrial dysfunction, abnormal right ventricular-pulmonary artery coupling, ischemia, or obesity phenotypes. In addition, imaging enables risk stratification for HFpEF. This article provides a critical appraisal of the role of echocardiography in the diagnosis and evaluation of HFpEF.

Correlation with invasive left ventricular filling pressures and prognostic relevance of the echocardiographic diastolic parameters used in the 2016 ESC heart failure guidelines and in the 2016 ASE/EACVI recommendations: a systematic review in patients with heart failure with preserved ejection fraction

AIMS

Five echocardiographic parameters-left atrial volume index, left ventricular mass index, tricuspid regurgitation velocity, myocardial tissue velocity, and the ratio of early mitral inflow to tissue velocity of the mitral annulus (E/e')-are recommended in both the current European Society of Cardiology heart failure guidelines and the American Society of Echocardiography/European Association of Cardiovascular Imaging recommendations for the evaluation of left ventricular diastolic function. We aimed to perform a systematic review of these echocardiographic parameters at resting conditions for their correlation with left ventricular filling pressures in patients with heart failure with preserved ejection fraction (HFpEF). In addition, the prognostic value of these parameters was assessed.

METHODS AND RESULTS

Nine studies reported the correlation between echocardiography and invasive haemodynamics, and 18 papers reported on the prognostic value of echocardiography in HFpEF. Among the parameters, most data were reported for E/e'. The pooled correlation coefficient r was 0.56 for the relation between E/e' and invasively measured filling pressures. Combined weighted-mean meta-analysis of prognostic studies resulted in a hazard ratio of 1.05 (95% confidence interval 1.03-1.06) per unit increase in E/e' for the combined outcome of all-cause mortality and cardiovascular hospitalization. The other echocardiographic parameters, when taken individually, had similar or lower association with prognosis.

CONCLUSION

Only a small number of studies validated the use of echocardiographic parameters at rest in patients with HFpEF. The best established parameter appears to be E/e', but the existing data only show modest correlations of E/e' with invasive filling pressures and outcomes in HFpEF.

Predictors of diastolic dysfunction in ethnic groups: observations from the Hypertensive Cohort of The Ethnic-Echocardiographic Heart of England Screening Study (E-ECHOES)

The study aimed to establish a relationship of ethnicity to diastolic dysfunction in subjects of African-Caribbean and South Asian origins and the impact of diastolic dysfunction and ethnicity on all-cause and cardiovascular mortality.

Hypertensive subjects with ejection fraction ≥55% and no history of ischemic heart disease/valve pathology (n=1546, 830 South Asians and 716 African-Caribbeans) were identified from the Ethnic - Echocardiographic Heart of England Screening Study (E-ECHOES). Diastolic function and cardiac remodelling were measured by echocardiography.

African-Caribbean ethnicity was associated with lower prevalence of having diastolic dysfunction (odds ratio 0.67, 95% confidence interval 0.51-0.87, p=0.003) and increased left ventricular filling pressure (odds ratio 0.48, 95% confidence interval 0.34-0.69, p<0.001) as well as lower left atrial index (p<0.001). This was the case despite the fact that African-Caribbean ethnicity was independently associated with higher left ventricular mass index (p<0.001). Ninety-two deaths (6%) occurred during 68±21 months follow up. On Cox regression analysis, South Asian ethnicity (p=0.024) was predictive of all-cause death before adjustment for parameters of diastolic dysfunction, but it was no longer predictive of death after accounting for these variables.

South Asian ethnicity is independently associated with worse parameters of diastolic function in hypertension, despite African-Caribbeans having more prominent hypertrophy.

Echocardiographic risk markers of sudden death in patients with temporal lobe epilepsy

Patients with epilepsy (PWE) have an increased risk for sudden unexpected death compared to the general population. Echocardiography can analyze structural and functional heart changes that have impact on outcomes, including sudden cardiac and all-cause death. Our hypothesis is that subtle heart abnormalities occur in PWE. Thirty patients with temporal lobe epilepsy without any known cardiovascular disease, followed for at least 1 year, were enrolled between July 2015 and July 2016 and submitted to a 12-lead electrocardiogram, treadmill test and transthoracic echocardiogram. PWE were matched with individuals without epilepsy by sex, age and body mass index. A literature review of studies comparing echocardiographic findings in PWE and individuals without epilepsy was performed. PWE had a higher left ventricle stiffness (β= 5.97 ± 0.05 × 5.94 ± 0.03; p = 0.02), left ventricle filling pressures (9.7 ± 1.3 mmHg × 9 ± 0.8; p = 0.02) and a greater left atrial volume (44.7 ± 13.6 ml × 34.1 ± 9.6 ml; p = 0.003). Seventeen (56.6%) PWE had a total of 22 of six known echocardiographic markers related to increased risk for sudden death in the general population, versus 11 (36.7%) controls with 12 markers (p = 0.07). Stiffness is related to fibrosis through extracellular matrix deposition, which promotes systolic and diastolic dysfunction and arrhythmogenesis. Subtle echocardiographic findings in PWE could help to explain why this population has an increased risk to die suddenly.

Left Ventricular Torsion Shear Angle Volume Approach for Noninvasive Evaluation of Diastolic Dysfunction in Preserved Ejection Fraction

BACKGROUND

Accurate noninvasive diagnostic tools for evaluating left ventricular (LV) diastolic dysfunction (LVDD) are limited in preserved LV ejection fraction. We previously proposed the relationship of normalized rate of change in LV torsion shear angle (φ') to corresponding rate of change in LV volume (V') during early diastole (represented as -dφ'/dV') as a measure of LV diastolic function. We prospectively evaluated diagnostic accuracy of -dφ'/dV' in respect to invasive LV parameters.

METHODS AND RESULTS

Participants (n=36, age 61±7 years) with LV ejection fraction ≥50% and no acute myocardial infarction undergoing coronary angiography for chest pain and/or dyspnea evaluation were studied. High-fidelity invasive LV pressure measurements and cardiac magnetic resonance imaging with tissue tagging were performed. τ, the time constant of LV diastolic relaxation, was 58±10 milliseconds (mean±SD), and LV end-diastolic pressure was 14.5±5.5 mm Hg. Cardiac magnetic resonance imaging-derived -dφ'/dV' was 5.6±3.7. The value of -dφ'/dV' correlated with both τ and LV end-diastolic pressure (r=0.39 and 0.36, respectively, P<0.05). LVDD was defined as τ>48 milliseconds and LV end-diastolic pressure >12 mm Hg (LVDD1), or, alternatively, τ>48 milliseconds and LV end-diastolic pressure >16 mm Hg (LVDD2). Area under the curve (AUC) of -dφ'/dV' for identifying LVDD1 was 0.83 (0.67-0.98, P=0.001), with sensitivity/specificity of 72%/100% for -dφ'/dV' ≥6.2. AUC of -dφ'/dV' for identifying LVDD_2 was 0.82 (0.64-1.00, P=0.006), with sensitivity/specificity of 76%/85% for -dφ'/dV' ≥6.9. There were good limits of agreement between pre- and post-nitroglycerin -dφ'/dV'.

CONCLUSIONS

The -dφ'/dV' obtained from the LV torsion volume loop is a promising parameter for assessing global LVDD with preserved LV ejection fraction and requires further evaluation.

Echocardiographic Detection of Increased Ventricular Diastolic Stiffness in Pediatric Heart Transplant Recipients: A Pilot Study

BACKGROUND

Pediatric heart transplant recipients are at risk for increased left ventricular (LV) diastolic stiffness. However, the noninvasive evaluation of LV stiffness has remained elusive in this population. The objective of this study was to compare novel echocardiographic measures of LV diastolic stiffness versus gold-standard measures derived from pressure-volume loop (PVL) analysis in pediatric heart transplant recipients.

METHODS

Patients undergoing left heart catheterization were prospectively enrolled. PVLs were obtained via conductance. The end-diastolic pressure-volume relationship was obtained via balloon occlusion. The stiffness constant, β, was calculated. Echocardiographic measures of diastolic function were derived from spectral and tissue Doppler and two-dimensional speckle-tracking. Ventricular volumes were measured using three-dimensional echocardiography. The novel echocardiographic estimates of ventricular stiffness included E:e'/end-diastolic volume (EDV) and E:early diastolic strain rate/EDV.

RESULTS

Of 24 children, 18 were heart transplant recipients. Six control patients had hemodynamically insignificant patent ductus arteriosus or coronary fistula. The mean age was 9.1 ± 5.6 years. Median end-diastolic pressure was 9 mm Hg (interquartile range, 8-13 mm Hg). Lateral E:e'/EDV (r = 0.59, P < .01), septal E:e'/EDV (r = 0.57, P < .01), and (E:circumferential early diastolic strain rate)/EDV (r = 0.54, P < .01) correlated with β. Lateral E:e'/EDV displayed a C statistic of 0.93 in detecting patients with abnormal LV stiffness (β > 0.015 mL^-1). A lateral E:e'/EDV of >0.15 mL^-1 had 89% sensitivity and 93% specificity in detecting an abnormal β.

CONCLUSIONS

Echocardiographic estimates of ventricular stiffness may be accurate compared with the gold standard in pediatric heart transplant recipients. The clinical usefulness of these noninvasive measures in assessing LV stiffness merits further study in children.

Renal Denervation Reduces Pulmonary Vascular Remodeling and Right Ventricular Diastolic Stiffness in Experimental Pulmonary Hypertension

Neurohormonal overactivation plays an important role in pulmonary hypertension (PH). In this context, renal denervation, which aims to inhibit the neurohormonal systems, may be a promising adjunct therapy in PH. In this proof-of-concept study, we have demonstrated in 2 experimental models of PH that renal denervation delayed disease progression, reduced pulmonary vascular remodeling, lowered right ventricular afterload, and decreased right ventricular diastolic stiffness, most likely by suppression of the renin-angiotensin-aldosterone system.

Premature Cardiac Aging in South Asian Compared to Afro-Caribbean Subjects in a Community-Based Screening Study

BACKGROUND

People of South Asian (SAs) and African Caribbean (AC) origin have increased cardiovascular morbidity, but underlying mechanisms are poorly understood. Aging is the key predictor of deterioration in diastolic function, which can be assessed by echocardiography using E/e' ratio as a surrogate of left ventricular (LV) filling pressure. The study aimed to assess a possibility of premature cardiac aging in SA and AC subjects.

METHODS AND RESULTS

We studied 4540 subjects: 2880 SA and 1660 AC subjects. All participants underwent detailed echocardiography, including LV ejection fraction, average septal-lateral E/e', and LV mass index (LVMI). When compared to ACs, SAs were younger, with lower mean LVMI, systolic blood pressure (BP), diastolic BP, and body mass index (BMI), as well as a lower prevalence of hypertension and smoking (P≤0.001 for all). In a multivariate linear regression model including age, sex, ethnicity, BP, heart rate, BMI, waist circumference, LVMI, history of smoking, hypertension, coronary artery disease, diabetes mellitus, medications, SA origin was independently associated with higher E/e' (regression coefficient±standard error, -0.66±0.10; P<0.001, adjusted R2 for the model 0.21; P<0.001). Furthermore, SAs had significantly accelerated age-dependent increase in E/e' compared to ACs. On multivariable Cox regression analysis without adjustment for E/e', SA ethnicity was independently predictive of mortality (P=0.04). After additional adjustment for E/e', the ethnicity lost its significance value, whereas E/e' was independently predictive of higher risk of death (P=0.008).

CONCLUSIONS

Premature cardiac aging is evident in SAs and may contribute to high cardiovascular morbidity in this ethnic group, compared to ACs.

Low level exercise echocardiography helps diagnose early stage heart failure with preserved ejection fraction: a study of echocardiography versus catheterization

BACKGROUND

Increased left ventricular end-diastolic pressure (LVEDP) with exercise is an early sign of heart failure with preserved left ventricular ejection fraction (LVEF). The abnormal exercise increase in LVEDP is nonlinear, with most change occurring at low-level exercise. Data on non-invasive approach of this condition are scarce. Our objective was assessing E/e' to estimate low level exercise LVEDP using a direct invasive measurement as the reference method.

METHODS AND RESULTS

Sixty patients with LVEF >50 % prospectively underwent both exercise cardiac catheterization and echocardiography. E/e' was measured at rest and during low-level exercise. Abnormal LVEDP was defined as >16 mmHg. Patients with a history of coronary artery disease and/or abnormal LV morphology were classified as having apparent cardiac disease (CD). Thirty-four (57 %) patients had elevated LVEDP only during exercise. Most of the change in LVEDP occurred since the first exercise level (25 W). There was a correlation between LVEDP and septal E/e' at rest and during exercise. Lateral E/e' and E/average e' ratio had worse correlations with LVEDP. In the whole population, exercise septal E/e' at 25 W had the best accuracy for abnormal exercise LVEDP, area under curve (AUC) = 0.79. However, while low-level exercise septal E/e' had a high accuracy in CD patients (n = 26, AUC = 0.96), E/e' was not linked to LVEDP in patients without CD (n = 34).

CONCLUSION

Low-level exercise septal E/e' is valuable for predicting abnormal exercise LVEDP in patients with preserved LVEF and apparent CD. However, this new diagnosis approach appears not reliable in patients with normal LV morphology and without coronary artery disease.

CLINICAL TRIAL REGISTRATION

https://clinicaltrials.gov . Unique identifier: NCT01714752.

Early-stage heart failure with preserved ejection fraction in the pig: a cardiovascular magnetic resonance study

BACKGROUND

The hypertensive deoxy-corticosterone acetate (DOCA)-salt-treated pig (hereafter, DOCA pig) was recently introduced as large animal model for early-stage heart failure with preserved ejection fraction (HFpEF). The aim of the present study was to evaluate cardiovascular magnetic resonance (CMR) of DOCA pigs and weight-matched control pigs to characterize ventricular, atrial and myocardial structure and function of this phenotype model.

METHODS

Five anesthetized DOCA and seven control pigs underwent 3 T CMR at rest and during dobutamine stress. Left ventricular/atrial (LV/LA) function and myocardial mass (LVMM), strains and torsion were evaluated from (tagged) cine imaging. 4D phase-contrast measurements were used to assess blood flow and peak velocities, including transmitral early-diastolic (E) and myocardial tissue (E') velocities and coronary sinus blood flow. Myocardial perfusion reserve was estimated from stress-to-rest time-averaged coronary sinus flow. Global native myocardial T1 times were derived from prototype modified Look-Locker inversion-recovery (MOLLI) short-axis T1 maps. After in-vivo measurements, transmural biopsies were collected for stereological evaluation including the volume fractions of interstitium (V_V(int/LV)) and collagen (V_V(coll/LV)). Rest, stress, and stress-to-rest differences of cardiac and myocardial parameters in DOCA and control animals were compared by t-test.

RESULTS

In DOCA pigs LVMM (p < 0.001) and LV wall-thickness (end-systole/end-diastole, p = 0.003/p = 0.007) were elevated. During stress, increase of LV ejection-fraction and decrease of end-systolic volume accounted for normal contractility reserves in DOCA and control pigs. Rest-to-stress differences of cardiac index (p = 0.040) and end-diastolic volume (p = 0.042) were documented. Maximal (p = 0.042) and minimal (p = 0.012) LA volumes in DOCA pigs were elevated at rest; total LA ejection-fraction decreased during stress (p = 0.006). E' was lower in DOCA pigs, corresponding to higher E/E' at rest (p = 0.013) and stress (p = 0.026). Myocardial perfusion reserve was reduced in DOCA pigs (p = 0.031). T1-times and V_V(int/LV) did not differ between groups, whereas V_V(coll/LV) levels were higher in DOCA pigs (p = 0.044).

CONCLUSIONS

LA enlargement, E' and E/E' were the markers that showed the most pronounced differences between DOCA and control pigs at rest. Inadequate increase of myocardial perfusion reserve during stress might represent a metrics for early-stage HFpEF. Myocardial T1 mapping could not detect elevated levels of myocardial collagen in this model.

TRIAL REGISTRATION

The study was approved by the local Bioethics Committee of Vienna, Austria (BMWF-66.010/0091-II/3b/2013).

Early-stage heart failure with preserved ejection fraction in the pig: a cardiovascular magnetic resonance study

BACKGROUND

The hypertensive deoxy-corticosterone acetate (DOCA)-salt-treated pig (hereafter, DOCA pig) was recently introduced as large animal model for early-stage heart failure with preserved ejection fraction (HFpEF). The aim of the present study was to evaluate cardiovascular magnetic resonance (CMR) of DOCA pigs and weight-matched control pigs to characterize ventricular, atrial and myocardial structure and function of this phenotype model.

METHODS

Five anesthetized DOCA and seven control pigs underwent 3 T CMR at rest and during dobutamine stress. Left ventricular/atrial (LV/LA) function and myocardial mass (LVMM), strains and torsion were evaluated from (tagged) cine imaging. 4D phase-contrast measurements were used to assess blood flow and peak velocities, including transmitral early-diastolic (E) and myocardial tissue (E') velocities and coronary sinus blood flow. Myocardial perfusion reserve was estimated from stress-to-rest time-averaged coronary sinus flow. Global native myocardial T1 times were derived from prototype modified Look-Locker inversion-recovery (MOLLI) short-axis T1 maps. After in-vivo measurements, transmural biopsies were collected for stereological evaluation including the volume fractions of interstitium (VV(int/LV)) and collagen (VV(coll/LV)). Rest, stress, and stress-to-rest differences of cardiac and myocardial parameters in DOCA and control animals were compared by t-test.

RESULTS

In DOCA pigs LVMM (p < 0.001) and LV wall-thickness (end-systole/end-diastole, p = 0.003/p = 0.007) were elevated. During stress, increase of LV ejection-fraction and decrease of end-systolic volume accounted for normal contractility reserves in DOCA and control pigs. Rest-to-stress differences of cardiac index (p = 0.040) and end-diastolic volume (p = 0.042) were documented. Maximal (p = 0.042) and minimal (p = 0.012) LA volumes in DOCA pigs were elevated at rest; total LA ejection-fraction decreased during stress (p = 0.006). E' was lower in DOCA pigs, corresponding to higher E/E' at rest (p = 0.013) and stress (p = 0.026). Myocardial perfusion reserve was reduced in DOCA pigs (p = 0.031). T1-times and VV(int/LV) did not differ between groups, whereas VV(coll/LV) levels were higher in DOCA pigs (p = 0.044).

CONCLUSIONS

LA enlargement, E' and E/E' were the markers that showed the most pronounced differences between DOCA and control pigs at rest. Inadequate increase of myocardial perfusion reserve during stress might represent a metrics for early-stage HFpEF. Myocardial T1 mapping could not detect elevated levels of myocardial collagen in this model.

TRIAL REGISTRATION

The study was approved by the local Bioethics Committee of Vienna, Austria (BMWF-66.010/0091-II/3b/2013).

Spectral transfer function analysis of respiratory hemodynamic fluctuations predicts end-diastolic stiffness in preserved ejection fraction heart failure

Preserved ejection fraction heart failure (HFpEF) diagnosis remains controversial, and invasive left ventricular (LV) hemodynamic evaluation and/or exercise testing is advocated by many. The stiffer HFpEF myocardium may show impaired stroke volume (SV) variation induced by fluctuating LV filling pressure during ventilation. Our aim was to investigate spectral transfer function (STF) gain from end-diastolic pressure (EDP) to indexed SV (SVi) in experimental HFpEF. Eighteen-week-old Wistar-Kyoto (WKY) and ZSF1 lean (ZSF1 Ln) and obese rats (ZSF1 Ob) randomly underwent LV open-chest (OC, n = 8 each group) or closed-chest hemodynamic evaluation (CC, n = 6 each group) under halogenate anesthesia and positive-pressure ventilation at constant inspiratory pressure. Beat-to-beat fluctuations in hemodynamic parameters during ventilation were assessed by STF. End-diastolic stiffness (βi) and end-systolic elastance (Eesi) for indexed volumes were obtained by inferior vena cava occlusion in OC (multibeat) or single-beat method estimates in CC. ZSF1 Ob showed higher EDP spectrum (P < 0.001), higher STF gain between end-diastolic volume and EDP, and impaired STF gain between EDP and SVi compared with both hypertensive ZSF1 Ln and normotensive WKY controls (P < 0.001). Likewise βi was only higher in ZSF1 Ob while Eesi was raised in both ZSF1 groups. On multivariate analysis βi and not Eesi correlated with impaired STF gain from EDP to SVi (P < 0.001), and receiver-operating characteristics analysis showed an area under curve of 0.89 for higher βi prediction (P < 0.001). Results support further clinical testing of STF analysis from right heart catheterization-derived EDP surrogates to noninvasively determined SV as screening/diagnostic tool to assess myocardial stiffness in HFpEF.

A porcine model of hypertensive cardiomyopathy: implications for heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFPEF) evolves with the accumulation of risk factors. Relevant animal models to identify potential therapeutic targets and to test novel therapies for HFPEF are missing. We induced hypertension and hyperlipidemia in landrace pigs (n = 8) by deoxycorticosteroneacetate (DOCA, 100 mg/kg, 90-day-release subcutaneous depot) and a Western diet (WD) containing high amounts of salt, fat, cholesterol, and sugar for 12 wk. Compared with weight-matched controls (n = 8), DOCA/WD-treated pigs showed left ventricular (LV) concentric hypertrophy and left atrial dilatation in the absence of significant changes in LV ejection fraction or symptoms of heart failure at rest. The LV end-diastolic pressure-volume relationship was markedly shifted leftward. During simultaneous right atrial pacing and dobutamine infusion, cardiac output reserve and LV peak inflow velocities were lower in DOCA/WD-treated pigs at higher LV end-diastolic pressures. In LV biopsies, we observed myocyte hypertrophy, a shift toward the stiffer titin isoform N2B, and reduced total titin phosphorylation. LV superoxide production was increased, in part attributable to nitric oxide synthase (NOS) uncoupling, whereas AKT and NOS isoform expression and phosphorylation were unchanged. In conclusion, we developed a large-animal model in which loss of LV capacitance was associated with a titin isoform shift and dysfunctional NOS, in the presence of preserved LV ejection fraction. Our findings identify potential targets for the treatment of HFPEF in a relevant large-animal model.

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.