Comparison of the Diastolic Stress Test With a Combined Resting Echocardiography and Biomarker Approach to Patients With Exertional Dyspnea: Diagnostic and Prognostic Implications

Stress Echocardiography for Assessment of Diastolic Function

PURPOSE OF REVIEW

Diastolic dysfunction is an important, though often underappreciated, cause for exertional dyspnea. Echocardiography enables noninvasive evaluation of diastolic function and filling pressure, but images acquired at rest may be insensitive for detection of exertional abnormalities. This review focuses on stress echocardiography to assess diastolic function, including traditional and novel techniques, with emphasis on specific patient sub-groups in whom this testing may be valuable.

RECENT FINDINGS

Emerging data informs patient selection for diastolic stress testing. Further, increasing literature provides considerations for performance and interpretation of diastolic metrics relevant to patients with heart failure with preserved ejection fraction, hypertrophic cardiomyopathy, athletes, and those with microvascular coronary dysfunction. Methods, such as speckle-tracking and multi-modality imaging, provide additional and complementary information for non-invasive diastolic assessment. This review serves as a guide to optimally utilize existing and novel techniques of stress echocardiography for diastolic assessment across a broad range of patients.

Left Ventricular Diastolic Dysfunction in Cardiac Surgery: A Narrative Review

Cardiac relaxation is a complex process that involves various interconnected characteristics and, along with contractile properties, determines stroke volume. Perioperative ischemia-reperfusion injury and left ventricular diastolic dysfunction (DD) are characterized by the left ventricle's inability to receive a sufficient blood volume under adequate preload. Baseline DD and perioperative DD have an impact on postoperative complications, length of hospital stay, and major clinical outcomes in a variety of cardiac pathologies. Several baseline and perioperative factors, such as age, female sex, hypertension, left ventricle hypertrophy, diabetes, and perioperative ischemia-reperfusion injury, contribute to the risk of DD. The recommended diagnostic criteria available in guidelines have not been validated in the perioperative settings and still need clarification. Timely diagnosis of DD might be crucial for effectively treating postoperative low cardiac output syndrome. This implies the need for an individualized approach to fluid infusion strategy, cardiac rate and rhythm control, identification of extrinsic causes, and administration of drugs with lusitropic effects. The purpose of this review is to consolidate scattered information on various aspects of diastolic dysfunction in cardiac surgery and provide readers with well-organized and clinically applicable information.

2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure" replaces the "2013 ACCF/AHA Guideline for the Management of Heart Failure" and the "2017 ACC/AHA/HFSA Focused Update of the 2013 ACCF/AHA Guideline for the Management of Heart Failure." The 2022 guideline is intended to provide patient-centric recommendations for clinicians to prevent, diagnose, and manage patients with heart failure.

METHODS

A comprehensive literature search was conducted from May 2020 to December 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from MEDLINE (PubMed), EMBASE, the Cochrane Collaboration, the Agency for Healthcare Research and Quality, and other relevant databases. Additional relevant clinical trials and research studies, published through September 2021, were also considered. This guideline was harmonized with other American Heart Association/American College of Cardiology guidelines published through December 2021. Structure: Heart failure remains a leading cause of morbidity and mortality globally. The 2022 heart failure guideline provides recommendations based on contemporary evidence for the treatment of these patients. The recommendations present an evidence-based approach to managing patients with heart failure, with the intent to improve quality of care and align with patients' interests. Many recommendations from the earlier heart failure guidelines have been updated with new evidence, and new recommendations have been created when supported by published data. Value statements are provided for certain treatments with high-quality published economic analyses.

2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure

AIM

The "2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure" replaces the "2013 ACCF/AHA Guideline for the Management of Heart Failure" and the "2017 ACC/AHA/HFSA Focused Update of the 2013 ACCF/AHA Guideline for the Management of Heart Failure." The 2022 guideline is intended to provide patient-centric recommendations for clinicians to prevent, diagnose, and manage patients with heart failure.

METHODS

A comprehensive literature search was conducted from May 2020 to December 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from MEDLINE (PubMed), EMBASE, the Cochrane Collaboration, the Agency for Healthcare Research and Quality, and other relevant databases. Additional relevant clinical trials and research studies, published through September 2021, were also considered. This guideline was harmonized with other American Heart Association/American College of Cardiology guidelines published through December 2021.

STRUCTURE

Heart failure remains a leading cause of morbidity and mortality globally. The 2022 heart failure guideline provides recommendations based on contemporary evidence for the treatment of these patients. The recommendations present an evidence-based approach to managing patients with heart failure, with the intent to improve quality of care and align with patients' interests. Many recommendations from the earlier heart failure guidelines have been updated with new evidence, and new recommendations have been created when supported by published data. Value statements are provided for certain treatments with high-quality published economic analyses.

Advanced Cardiovascular Imaging in Clinical Heart Failure

Cardiovascular imaging is the cornerstone of the assessment of patients with heart failure. Although noninvasive volumetric estimation of the cardiac function is an essential and indisputably useful clinical tool, cardiac imaging has evolved and matured to offer detailed functional, hemodynamic, and tissue characterization. The adoption of a new framework to diagnose and phenotype heart failure that incorporates comprehensive imaging assessment has been lacking in clinical trials. The present review offers a general overview of available imaging strategies for patients with heart failure.

The Heart Failure with Preserved Ejection Fraction Conundrum-Redefining the Problem and Finding Common Ground?

PURPOSE OF REVIEW

Heart failure with preserved ejection fraction (HFpEF) or diastolic heart failure (DHF) makes up more than half of all congestive heart failure presentations (CHF). With an ageing population, the case load and the financial burden is projected to increase, even to epidemic proportions. CHF hospitalizations add too much of the financial and infrastructure strain. Unlike systolic heart failure (SHF), much is still either uncertain or unknown. Specifically, in epidemiology, the disease burden is established; however, risk factors and pathophysiological associations are less clear; diagnostic tools are based on rigid parameters without the ability to accurately monitor treatments effects and disease progression; finally, therapeutics are similar to SHF but without prognostic data for efficacy.

RECENT FINDINGS

The last several years have seen guidelines changing to account for greater epidemiological observations. Most of these remain general observation of shortness of breath symptom matched to static echocardiographic parameters. The introduction of exercise diastolic stress test has been welcome and warrants greater focus. HFpEF is likely to see new thinking in the coming decades. This review provides some of perspective on this topic.

Diagnostic and prognostic implications of heart failure with preserved ejection fraction scoring systems

Aims

We sought to compare the generalizability and prognostic implications of heart failure with preserved ejection fraction (HFpEF) scores (HFA‐PEFF and H₂FPEF score) in Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist (TOPCAT) and Phosphodiesterase‐5 Inhibition to Improve Clinical Status and Exercise Capacity in Heart Failure with Preserved Ejection Fraction (RELAX) trial participants and matched controls from the Atherosclerosis Risk in Community (ARIC) study.

Methods and results

Based on the respective scores, the study participants from the TOPCAT (N = 356), RELAX (N = 216), and ARIC (N = 379) studies were categorized as having a low, intermediate, or high likelihood of HFpEF. Age, sex, and race matched controls free of cardiovascular disease who had unexplained dyspnoea were used to evaluate the diagnostic performance. The prognostic value of scores was assessed using multivariable‐adjusted Cox regression analyses. The median HFA‐PEFF scores in the TOPCAT, RELAX, and ARIC studies were 5.0 [interquartile range (IQR): 5.0–6.0], 4.0 (IQR: 2.0–4.0), and 3.0 (IQR: 2.0–4.0), respectively. The median H₂FPEF scores in the three studies were 5.5 (IQR: 4.0–7.0), 6.0 (IQR: 4.0–7.0), and 3.0 (IQR: 2.0–5.0), respectively. A low HFA‐PEFF and H₂FPEF score can rule out HFpEF with high sensitivity (99.5% and 99.6%, respectively) and negative predictive value (95.7% and 98.3%, respectively). A high HFA‐PEFF and H₂FPEF score can rule‐in HFpEF with good specificity (82.8% and 95.6%, respectively) and positive predictive value (79.9% and 90.4%, respectively). Among TOPCAT participants, the hazard for adverse cardiovascular events per point increase in HFA‐PEFF and H₂FPEF score was 1.26 (95% confidence interval: 0.98–1.63) and 1.01 (95% confidence interval: 0.88–1.15), respectively. A higher H₂FPEF score was associated with lower peak oxygen intake in RELAX trial participants (adjusted P = 0.01).

Conclusions

The HFA‐PEFF and the H₂FPEF scores are reliable diagnostic tools for HFpEF. The prognostic utility of HFpEF scores requires further validation in larger rigorously phenotyped populations.

Left Atrial Strain in Evaluation of Heart Failure with Preserved Ejection Fraction

BACKGROUND

Patients with heart failure with preserved ejection fraction (HFpEF) may have elevated left ventricular filling pressure with exercise (LVFP-ex), despite normal LVFP at rest. The aim of this study was to assess the diagnostic value of resting left atrial strain (LAS) in detecting elevated LVFP-ex in patients with dyspnea evaluated on exercise stress echocardiography.

METHODS

Two-dimensional speckle-tracking analysis for LAS was performed in 669 consecutive patients (mean age, 64 ± 14 years; 53% men) who underwent treadmill echocardiographic evaluation and had left ventricular ejection fractions ≥ 50%. Assessment of LVFP at rest LVFP-ex was based on the 2016 American Society of Echocardiography guidelines for diastolic function assessment. An E/e' ratio ≥ 15 after exercise is considered to indicate elevated LVFP-ex. A continuous diagnostic score of HFpEF was calculated on the basis of the European Society of Cardiology HFA-PEFF diagnostic algorithm.

RESULTS

LAS_reservoir was lowest in patients with elevated LVFP at rest (n = 81) and lower in those with normal resting filling pressure who developed elevated LVFP-ex (n = 108) compared with those who maintained normal LVFP-ex (29.0 ± 5.2% vs 33.1 ± 5.0% vs 39.3 ± 4.8%, P < .001). Lower LAS_reservoir was associated with worse exercise capacity as assessed by metabolic equivalents, exercise time, and functional aerobic capacity (multivariate-adjusted P values all < .05). In patients with normal or indeterminate LVFP at rest (n = 587), LAS_reservoir and preexercise HFA-PEFF score demonstrated areas under the curve of 0.82 and 0.7, respectively, for elevated LVFP-ex. There were 28% higher odds of developing elevated LVFP-ex per 1% decrease in LAS_reservoir (odds ratio, 0.78; 95% CI, 0.74-0.82). Among patients with intermediate scores (n = 461), 123 developed elevations in LVFP-ex and were classified as having HFpEF per the diagnostic algorithm. The addition of LAS_reservoir improved the diagnostic value of HFA-PEFF score for HFpEF (area under the curve increased from 0.71 to 0.80, P = .01).

CONCLUSIONS

LAS_reservoir has potential to identify patients with intermediate scores for HFpEF who may develop elevated LVFP-ex only and is therefore a promising alternative to aid in diagnosis when exercise testing is not feasible.

Exercise E/e' Is a Determinant of Exercise Capacity and Adverse Cardiovascular Outcomes in Chronic Kidney Disease

OBJECTIVES

This study sought to assess the relationship between E/e' and exercise capacity in patients with chronic kidney disease (CKD) and evaluate its prognostic role.

BACKGROUND

Patients with CKD have diastolic dysfunction, reduced physical fitness, and elevated risk of cardiovascular disease.

METHODS

Patients with stage 3 and 4 CKD without previous cardiac disease underwent resting and exercise stress echocardiograms with assessment of exercise E/e'. Patients were compared to age-, sex-, and risk factor-matched control individuals and were followed annually for 5 years for cardiovascular death and major adverse cardiovascular event(s) (MACE). Exercise capacity was assessed as metabolic equivalents (METs), with reduced exercise capacity defined as METs of ≤7. Raised exercise E/e' was defined as >13.

RESULTS

A total of 156 patients with CKD (age 62.8 ± 10.6 years; male: 62%) were compared to 156 matched control individuals. Patients with CKD were more likely to be anemic (p < 0.01) and had increased left ventricular mass (p < 0.01), larger left atrial volumes (p < 0.01), and higher resting (p < 0.01) and exercise E/e' (p < 0.01). Patients with CKD achieved lower exercise METs (p < 0.01), and more patients with CKD had METs of ≤7 (p < 0.01). Receiver-operating characteristic curves showed exercise E/e' (area under the curve [AUC]: 0.89; 95% CI: 0.84 to 0.95; p < 0.01) as the strongest predictor of reduced exercise capacity in patients with CKD. Over a follow-up period of 41.4 months, a raised exercise E/e' of >13 was an independent predictor of cardiovascular death and MACE on unadjusted and adjusted hazard models.

CONCLUSION

E/e' is a strong predictor of exercise capacity and METs achieved by patients with CKD. Exercise capacity was reduced in patients with CKD, presumably consequent to diastolic dysfunction. Elevated exercise E/e' in patients with CKD is an independent predictor of cardiovascular death and MACE.

Impaired global longitudinal strain in elderly patients with preserved ejection fraction is associated with raised post-exercise left ventricular filling pressure

BACKGROUND

The purpose of this study was to evaluate whether impaired resting global longitudinal strain (GLS) in elderly patients with preserved left ventricular (LV) ejection fraction (EF) is associated with raised post-exercise LV filling pressure estimated by the ratio of early diastolic transmitral flow velocity to annulus velocity (E/e').

METHODS

Seventy elderly patients (age = 74 ± 6 years, male 40 patients) who underwent treadmill stress echocardiography were studied. All patients had normal sinus rhythm, normal LV wall motion at rest, and had preserved LVEF ≥ 50%. Patients with exercise induced wall motion abnormality were not included. GLS at rest was measured using automated functional imaging.

RESULTS

Twenty-four of the 70 patients had raised post-exercise LV filling pressure indicated by septal E/e' ≥ 15.0. Patients with raised post-exercise LV filling pressure had smaller resting GLS than that in patients without it (- 16.9 ± 1.8 vs. - 19.6 ± 2.5%, respectively, p < 0.0001). Downward stepwise multivariate logistic regression analysis demonstrated that resting GLS was one of independent predictors of raised post-exercise E/e'. Receiver operating characteristic (ROC) curve analysis had demonstrated that optimal cutoff point for resting GLS to predict raised post-exercise E/e' was - 17.8% (sensitivity 83.3%, specificity 80.4%, respectively), and the area under the ROC curve was 0.820.

CONCLUSION

In elderly patients with preserved LVEF and without obvious myocardial ischemia, impaired resting GLS at rest is associated with raised post-exercise LV filling pressure estimated by E/e' ≥ 15.0.

Diagnostic algorithm for HFpEF: how much is the recent consensus applicable in clinical practice?

Heart failure with preserved ejection fraction (HFpEF) represents an important cardiovascular entity with increasing prevalence and relatively high mortality. The agreement about diagnostic algorithm for HFpEF is still missing. Echocardiographic approach remains the cornerstone in HFpEF diagnosis. Echocardiographic diastolic stress test provides numerous useful parameters that correlated well with indexes obtained by cardiac catheterization. Recently published consensus recommended new scoring system that included functional and structural echocardiographic parameters, as well as biomarkers. The new score for evaluation of HFpEF introduces a new set of parameters and proposed novel cutoff values for some of them. There are several important points that need to be resolved before full acceptance and clinical usage. First, some cutoff values are new and represent the result of expert consensus, without previous validation. Second, many patients with hypertension, obesity, and diabetes would be referred for further investigations as the result of this scoring, which is difficult to achieve in clinical circumstances. Third, the consensus equalized non-invasive and invasive diastolic stress tests in diagnosing of HFpEF, which is not a small issue. Namely, even though cardiac catheterization provides the final confirmation of elevated left ventricular filling pressures, it is still an invasive method, associated with procedural risk and other limitations. The aim of this review was to summarize the current knowledge diagnosis of HFpEF, as well as the recent consensus about diagnostic algorithm in patients with suspected HFpEF with its advantages and disadvantages.

Stress Echocardiography-Derived E/e' Predicts Abnormal Exercise Hemodynamics in Heart Failure With Preserved Ejection Fraction

Background

The correlation between echocardiographic parameters and hemodynamics data in patients with heart failure with preserved ejection fraction (HFpEF) is unclear. It is important to find a non-invasive echocardiographic parameter for predicting exercise pulmonary capillary wedge pressure (PCWP).

Aim

This study sought to determine the correlation between echocardiographic parameters and hemodynamics data at rest and during exercise in HFpEF patients.

Methods and Results

This study was a cross-sectional cohort exploratory analysis of baseline data from the ILO-HOPE trial. A total of 34 HFpEF patients were enrolled. The average age was 70 ± 12 years, and most (74%) were women. The patients underwent invasive cardiac catheterization and expired gas analysis at rest and during exercise. Echocardiography including tissue Doppler imaging was performed, and global longitudinal strain and other novel diastolic function indexes were analyzed at rest and during exercise. At rest, no significant correlation was noted between resting PCWP and echocardiographic parameters. However, a significant correlation was observed between post-exercise PCWP and stress E/e′ (septal, lateral, and mean) ratio (p = 0.003, 0.031, 0.012). Moreover, post-exercise ΔPCWP showed a good correlation with stress E/e′ (septal, lateral, and mean; all p ≤ 0.001) and global longitudinal strain (GLS) during exercise (p = 0.03). After multivariate regression analysis with adjustment for possible confounding factors including age and sex, there was still a significant correlation between post-exercise ΔPCWP and E/e′ (r = 0.62, p < 0.001 for E/e′_mean).

Conclusion

Only stress echocardiography derived tissue Doppler E/e′ ratio is closely correlated with abnormal exercise hemodynamics (PCWP and post-exercise ΔPCWP) in HFpEF. This echocardiographic marker is substantially more sensitive than other novel echocardiographic parameters during exercise, and may have significant diagnostic utility for ambulatory HFpEF patients with dyspnea.

Clinical Trial Registration

https://www.clinicaltrials.gov, identifier NCT03620526.

Practical Impact of New Diastolic Recommendations on Noninvasive Estimation of Left Ventricular Diastolic Function and Filling Pressures

BACKGROUND

In 2016, an update of the 2009 recommendations for the evaluation of left ventricular (LV) diastolic function (DF) was released by the American Society of Echocardiography and the European Association of Cardiovascular Imaging. The aims of this study were to assess the concordance between the 2016 and 2009 recommendations and to test the impact of the consideration of "myocardial disease" recommended in the 2016 update on the evaluation of diastolic dysfunction (DD) and LV filling pressures in patients with normal and reduced LV ejection fractions referred to a general echocardiography laboratory.

METHODS

A total of 1,508 outpatients referred to an echocardiography laboratory during a predefined 5-month period were prospectively enrolled. All patients underwent targeted clinical history and Doppler echocardiographic examination. DD and LV filling pressures were assessed according to 2009 and 2016 recommendations. Concordance was calculated using the κ coefficient and overall proportion of agreement.

RESULTS

Overall proportion of agreement between the two recommendations was 64.7% (κ = 0.43). Comparing the 2009 and 2016 recommendations, 47.5% and 36.1% patients, respectively, had DD (P < .0001), and 22.7% and 12.6% had elevated LV filling pressures (P < .0001). This difference remained significant in the setting of patients with normal LV ejection fractions (21.6% vs 10.7%, P < .0001). In the application of the 2016 recommendations, whether or not the presence of "myocardial disease" was considered, the prevalence of indeterminate diastolic function was, respectively, 7.3% versus 13.7%, while patients in whom the DD grade could not be determined were 8.1% versus 14.4% (P < .0001 for all).

CONCLUSIONS

Considering the presence of myocardial disease when applying the 2016 recommendations resulted in a lower prevalence of inconclusive diagnosis.

Diastolic Stress Testing Along the Heart Failure Continuum

PURPOSE OF REVIEW

This review summarizes recent developments highlighting the clinical utility of diastolic stress testing along the heart failure continuum.

RECENT FINDINGS

Invasive hemodynamic assessment of cardiac filling pressures during physiological stress is the gold-standard technique for unmasking diastolic dysfunction. Non-invasive surrogate techniques, such as Doppler ultrasound, have shown excellent agreement with invasive approaches and are now recommended by the American Society of Echocardiography and the European Association of Cardiovascular Imaging. While cycle exercise is often advocated, recent evidence supports the use of isometric handgrip as a viable alternative stressor. Diastolic stress testing is a powerful tool to enhance detection of diastolic dysfunction, is able to differentiate between cardiac and non-cardiac pathology, and should be incorporated into routine clinical assessment.

Echocardiographic Diastolic Stress Testing: What Does It Add?

PURPOSE OF REVIEW

Diastolic stress echocardiography may help facilitate the attribution of exertional dyspnea to cardiac and non-cardiac disease. It represents a non-invasive hemodynamic test to assess the patients with unexplained dyspnea. It can improve the diagnosis of heart failure with preserved ejection fraction (HFpEF) or diastolic heart failure.

RECENT FINDINGS

A number of studies have validated exercise E/e' as a measure of left ventricular (LV) filling pressure against invasively measured LV filling pressure using simultaneous exercise echocardiography-catheterization studies. Addition of E/e' during exercise echocardiography improved sensitivity for diagnosis of HFpEF compared with resting assessment alone, and its specificity can be improved if tricuspid regurgitation velocity also increases above the normal range with exercise. The independent prognostic value of exercise E/e' has also been well delineated in a number of studies. Diastolic stress exercise echocardiography should be considered for all patients with unexplained or exertional dyspnea and normal diastolic filling pressure or grade 1 diastolic dysfunction on resting echocardiography. Addition of diastolic assessment with exercise echocardiography improves the sensitivity of the test in patients with dyspnea and there are sufficient data to integrate diastolic exercise test into our clinical practice.

Detailed structural assessment of healthy interventricular septum in the presence of remodeling infarct in the free wall - A finite element model

Purpose

Computational modelling may improve the fundamental understanding of various mechanisms of diseases more particularly related to clinical challenges. In this study the effect of remodeling infarct presence in the left ventricle on the interventricular septal wall is studied using the finite element methods.

Methods

In this study, two rat heart (one model with healthy myocardium and one model with remodeling free wall and healthy septal wall) with magnetic resonance imaging data was gathered to reconstruct three-dimensional (3D) rat heart models. 3D data points from Segment® were imported into SolidEdge® for creation of 3D rat heart models. Abaqus® was used for finite element modeling.

Results

The strain in the healthy interventricular septum of the infarcted left ventricle wall increased when compared to the healthy interventricular septum in the healthy left ventricle. Similarly, the average stress in the healthy left ventricle was observed to have increased on the healthy the interventricular septum where the free wall is subjected to remodeling infarct. When comparing the infarcted models to the healthy model, it was found that the average strain had greatly increased by up to 50.0 %.

Conclusions

The remodeling infarct in the left ventricle has an impact on the healthy interventricular septal wall. Even though the interventricular septal wall was modelled as healthy, it was observed that it has undergone considerable changes in stresses and strains in circumferential and longitudinal direction. The observed changes in myocardial stresses and strains may result in poor global functioning of the heart.

Association of Reduced Apical Untwisting With Incident HF in Asymptomatic Patients With HF Risk Factors

OBJECTIVES

This study investigated the prognostic utility of left ventricular (LV) untwisting (UT) in the elderly patients at risk of heart failure (HF).

BACKGROUND

LV UT mechanics represent a unique combination of LV filling linking ventricular relaxation and suction. The value of this parameter in the prediction of outcomes in patients at risk of HF is unclear.

METHODS

A group of 465 asymptomatic subjects ≥65 years of age with ≥1 HF risk factor (hypertension, diabetes, obesity), recruited from the community, underwent clinical evaluation and echocardiography including measurement of LV apical and basal peak UT velocities. Cox regression analysis was used to identify predictors of new-onset HF and cardiovascular death after a mean follow-up of 18.2 ± 7.5 months.

RESULTS

A composite of both of the study endpoints occurred in 54 patients (11.6%). Adverse outcome was significantly associated with apical (hazard ratio [HR]: 0.98; 95% confidence interval [CI]: 0.96 to 0.99; p = 0.006) UT but not with basal (p = 0.18) UT. The prognostic value of apical UT was independent of and incremental to clinical data, as expressed by the ARIC (Atherosclerosis Risk In Communities) study risk score, left atrial volume index (LAVI), and LV global longitudinal strain (GLS). The addition of apical UT to the model including ARIC risk score, LAVI, and GLS was associated with a 41% improvement in reclassification (p = 0.006).

CONCLUSIONS

Echocardiographic assessment of apical UT provides incremental value in predicting adverse outcome in asymptomatic patients with HF risk factors. The inclusion of apical UT to the diagnostic algorithm may improve the prognostication process in this population.

Asymptomatic Left Ventricular Diastolic Dysfunction: Predicting Progression to Symptomatic Heart Failure

Asymptomatic left ventricular diastolic dysfunction (ALVDD) (diastolic abnormalities and normal ejection fraction in the absence of symptoms) is associated with incident heart failure (HF) and decreased survival. Abnormalities of diastolic function might therefore be included in the definition of stage B HF, which denotes individuals at risk for the development of HF. Imaging techniques, especially echocardiography, are necessary for the recognition of preclinical left ventricular (LV) diastolic disturbances, as well as further tracking of pathological changes and responses to treatment. The transition of ALVDD to symptomatic HF is underlain by multiple factors, including both cardiovascular and noncardiovascular determinants. The initiation of management strategies targeting cardiovascular and systemic comorbidities in patients identified as having ALVDD may delay symptomatic progression and improve prognosis.

Contribution of Cardiovascular Reserve to Prognostic Categories of Heart Failure With Preserved Ejection Fraction: A Classification Based on Machine Learning

BACKGROUND

The authors used cluster analysis of data from cardiovascular domains associated with exercise intolerance to help define prognostic phenotypes of patients with heart failure with preserved ejection fraction (HFpEF).

METHODS

Resting and postexercise echocardiography was performed in 177 patients with HFpEF and 51 asymptomatic control subjects sharing a common clinical profile. Patterns of features that determine exercise capacity were sought from automated hierarchical clustering of left ventricular (LV) diastolic and systolic function, left atrial function, right ventricular function, ventricular-arterial coupling, chronotropic reserve and myocardial fibrosis.

RESULTS

Automated clustering separated a distinct subgroup characterized by a relatively isolated impairment of LV systolic reserve. The clinical factors identified by this process were used to define two phenotypes of patients with symptomatic HFpEF: those with reduced chronotropic and/or diastolic reserve (abnormal CR/DR; n = 137) and those with preserved heart rate reserve and exertional E/e' ratio < 14 (normal CR/DR; n = 40). Change in global LV strain rate from rest to exercise was similar in patients with abnormal CR/DR (0.16 ± 0.18 sec^-1) and those with normal CR/DR (0.21 ± 0.17 sec^-1) and significantly lower than in asymptomatic subjects (0.54 ± 0.20 sec^-1; P < .001 for all). However, although the former group also showed abnormal longitudinal deformation, ventricular-arterial coupling, and cardiac output responses to exercise, the latter group showed only reduced LV systolic reserve. The normal CR/DR group had a lower incidence of cardiovascular hospitalization or death (P = .003) and heart failure hospitalization (P = .002) than the abnormal CR/DR group during 2-year follow-up.

CONCLUSIONS

Diminished LV systolic reserve may represent the major identifiable cardiac functional abnormality associated with exercise intolerance in some patients with HFpEF. Despite significant functional limitation, these patients are characterized by a better prognosis than subjects with HFpEF with more physiologic abnormalities.

Diastolic stress test echocardiography in patients with suspected heart failure with preserved ejection fraction: a pilot study

AIMS

The purpose of this pilot study was to assess the potential usefulness of diastolic stress test (DST) echocardiography in patients with suspected heart failure with preserved ejection fraction (HFpEF).

METHODS AND RESULTS

Patients with suspected HFpEF (left ventricular ejection fraction ≥ 50%, exertional dyspnoea, septal E/e' at rest 9-14, and N-terminal pro-B-type natriuretic peptide (NT-proBNP) at rest < 220 pg/mL; n = 13) and a control group constituted from asymptomatic patients with arterial hypertension (n = 19) and healthy subjects (n = 18) were included. All patients were analysed by two-dimensional and Doppler echocardiography at rest and during exercise (DST) and underwent cardiopulmonary exercise testing and NT-proBNP analysis during exercise. HFpEF during exercise was defined as exertional dyspnoea and peak VO₂  ≤ 20.0 mL/min/kg. In patients with suspected HFpEF at rest, 84.6% of these patients developed HFpEF during exercise, whereas in the group of asymptomatic patients with hypertension and healthy subjects, the rate of developed HFpEF during exercise was 0%. Regarding the diagnostic performance of DST to detect HFpEF during exercise, an E/e' ratio >15 during exercise was the most accurate parameter to detect HFpEF (accuracy 86%), albeit a low sensitivity (45.5%). Nonetheless, combining E/e' with tricuspid regurgitation (TR) velocity > 2.8 m/s during exercise provided a significant increase in the sensitivity to detect patients with HFpEF during exercise (sensitivity 72.7%, specificity 79.5%, and accuracy 78%). Consistent with these findings, an increase of E/e' was significantly linked to worse peak VO₂ , and the combination of an increase of both E/e' and TR velocity was associated with elevated NT-proBNP values during exercise.

CONCLUSIONS

The findings of this pilot study suggest that DST using E/e' ratio and TR velocity could be of potential usefulness to diagnose HFpEF during exercise in patients with suspected HFpEF at rest.

Diastolic stress echocardiography: from basic principles to clinical applications

Heart failure with preserved ejection fraction (HFpEF) looms as a major public heart challenge with increasing prevalence due to an ageing population. Diagnosis can be challenging due to non-specific symptomatology, low natriuretic peptide levels and equivocal diastology on resting echocardiography. Diastolic stress echocardiography represents a non-invasive option to refining the diagnosis in this subset of patients. Diastolic responses to exercise are most commonly measured with a non-invasive measure of left ventricular filling pressures (LVFP) estimated by the ratio of the early mitral inflow wave to early diastolic tissue velocity (E/e' ratio). This is measured pre- and post-exercise , and is highly feasible. An elevation of exercise E/e' >15 is classified as an abnormal response as per current guidelines. An alternative measure of exercise-related diastolic performance, the Diastolic Functional Reserve Index has also been proposed, but has not been as well studied as exercise E/e'. A number of studies have validated exercise E/e' as a measure of LVFP against invasively measured LVFP using simultaneous echocardiography-catheterisation studies. The independent prognostic value of exercise E/e' has also been well delineated in a number of studies. While diastolic stress echocardiography can be considered for all patients with suspected HFpEF, it is of particular value in patients with normal or equivocal diastolic indices on resting echocardiography.