Myocardial Strain in the Assessment of Patients With Heart Failure: A Review

Impaired left atrial function in adults and adolescents with corrected aortic coarctation

This study examined the left atrial (LA) function using two-dimensional (2D) strain analysis after aortic coarctation (CoA) repair, as well as relationships between LA function and patient characteristics, especially aortic arch anatomy. 56 patients (34 males, age: 31 ± 16 years) with CoA repair (46 post 'end-to-end anastomosis/subclavian flap') and 56 controls were studied. 2D strain imaging was performed to assess left ventricular (LV) and LA functions including peak-positive LA strain, early and late diastolic LA strains, and global longitudinal (LV-GLS) and circumferential (LV-GCS) strains. LA dysfunction (LAD) was defined as a peak-positive LA strain value lower than the mean value of the control group minus 2 SDs. Peak-positive LA strain, early and late diastolic LA strains, and LV-GLS were significantly lower in the CoA group while LV-GCS did not differ. No significant correlation was found between LA strain and either current age, age at initial repair, or blood pressure; Ea and LV-GLS were moderately correlated to peak-positive LA strain (r = 0.49, p < 0.001 and r =  - 0.55, p < 0.001, respectively). 23 CoA patients (41%) presented LAD (abnormal peak-positive LA strain < 25%). Among patients who underwent end-to-end anastomosis/subclavian flap, those with a non-romanesque aortic arch anatomy exhibited a significantly lower peak-positive LA strain. Ischemic stroke and atrial arrhythmia were more frequent in CoA patients with LAD. Our findings suggest that LAD may be prevalent late after CoA repair. Postoperative aortic arch anatomy may impact peak-positive LA strain.

Evaluation of Coronary Artery Disease in Patients with Atrial Fibrillation by Cardiac Computed Tomography for Catheter Ablation: CADAF-CT Trial 2

Objective We recently reported that routine cardiac computed tomography (CT) scans for radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) could steadily detect coronary artery lesions (CALs) and could accurately detect myocardial ischemia in 9% of patients with AF who underwent RFCA of AF. The aim of this study was to identify the independent risk factor (s) of myocardial ischemia in those patients. Methods Patient characteristics, blood test, CALs, Ordinal coronary calcium scoring (OCCS), and myocardial Ischemia (MI) were evaluated in 757 consecutive patients who underwent RFCA of AF. Results There were 685 and 72 patients without and with myocardial ischemia, respectively. A univariate analysis and multivariate statistical analysis revealed that a male gender (Odds ratio 2.11), a high number of co-existing coronary risk factors (NCCRF ≥3) (Odds ratio 2.03), an elevated brain natriuretic peptide level (BNP ≥100 pg/mL) (Odds ratio 3.37), an enlarged left atrial volume (≥90 mL) (Odds ratio 2.91), and a high OCCS (≥4) (Odds ratio 13.0) were independent risk factors of myocardial ischemia in patients undergoing RFCA of AF. Conclusion The high OCCS (≥4) by cardiac CT was the strongest independent risk factor of myocardial ischemia in those patients. However, physicians may be able to find the high risk patients of myocardial ischemia by evaluating a male gender, in the presence of a high NCCRF (≥3) and elevated BNP (≥100 pg/mL) without OCCS by cardiac CT in patients undergoing RFCA of AF.

Impaired left atrial stiffness in patients with corrected congenital left ventricular outflow obstructions

OBJECTIVE

We examined the left atrial stiffness index (LA Stiff) on echocardiography and its determinants in adults and adolescents with repaired congenital left ventricular outflow obstructions (c-LVOOs), including isolated subaortic stenosis (SAS), stenotic bicuspid aortic valve (BAV), and aortic coarctation (CoA).

METHODS

Seventy-two patients (43 males, age: 31 ± 15 years) with repaired c-LVOOs (SAS: n = 12; BAV: n = 27; CoA: n = 33) were compared to 72 age- and sex-matched controls. 2D strain imaging was performed to assess left ventricular (LV) and LA function, including peak positive longitudinal LA strain (LAS), late diastolic LA strain (LDS), and LV global longitudinal strain (GLS). The (E/Ea)/LAS ratio was used to calculate LA Stiff.

RESULTS

LA Stiff was significantly higher in the c-LVOO group than in the control group. Among the c-LVOO patients, the CoA group had the lowest GLS and the highest LA Stiff; no significant differences were found with respect to sex, hypertension history, smoking status, or repeated repair among c-LVOO subtypes. Multivariable regression analysis with the variables "BMI" and "c-LVOO subtype" revealed that BMI and c-LVOO subtypes were independently associated with LA Stiff (b = 0.290, P = .009 and b = 0.353, P = .002, respectively).

CONCLUSIONS

We documented abnormal LA Stiff values in adults and adolescents after c-LVOO repair. Patients with CoA demonstrated the most impaired LA Stiff values. Overweight may contribute to worse LA Stiff values. Further studies are required to determine the prognostic implications of LA Stiff in patients with repaired c-LVOOs.

Analogies and differences between cirrhotic cardiomyopathy and hepatopulmonary syndrome

Cirrhotic cardiomyopathy and hepatopulmonary syndrome are two quite frequent clinical entities that may complicate the course of liver cirrhosis. The common pathophysiological origin and the same clinical presentation make them difficult to compare. Cirrhotic cardiomyopathy and hepatopulmonary syndrome may start with dyspnea and breathlessness but the former is characterized by a chronic cardiac dysfunction and the latter by a defect of oxygenation due to pulmonary shunts formation. The focus is to differentiate them as soon as possible since the treatment is different until the patient undergoes liver transplant that is the real unique cure for them.

Heart Failure With Mid-range or Recovered Ejection Fraction: Differential Determinants of Transition

The recent definition of an intermediate clinical phenotype of heart failure (HF) based on an ejection fraction (EF) of between 40% and 49%, namely HF with mid-range EF (HFmrEF), has fuelled investigations into the clinical profile and prognosis of this patient group. HFmrEF shares common clinical features with other HF phenotypes, such as a high prevalence of ischaemic aetiology, as in HF with reduced EF (HFrEF), or hypertension and diabetes, as in HF with preserved EF (HFpEF), and benefits from the cornerstone drugs indicated for HFrEF. Among the HF phenotypes, HFmrEF is characterised by the highest rate of transition to either recovery or worsening of the severe systolic dysfunction profile that is the target of disease-modifying therapies, with opposite prognostic implications. This article focuses on the epidemiology, clinical characteristics and therapeutic approaches for HFmrEF, and discusses the major determinants of transition to HFpEF or HFrEF.

Evaluation of left ventricular myocardial movement in rats by velocity vector imaging

AIM

To use velocity vector imaging (VVI) technology to evaluate the correlation between the apical four-chamber view and short-axis myocardial movement in rats.

METHODS

We used 25 10-week-old male Sprague-Dawley rats to measure the myocardium peak systolic velocity (Vs; cm/s), peak diastolic velocity (Vd; cm/s), peak systolic strain (SR; %), peak systolic strain rate (SRs; 1/s), and peak diastolic strain rate (SRd; 1/s) from the apical four-chamber view of the left ventricle (LV) and the parasternal mitral valve (PMV)-level short-axis view, and to analyze the correlation between myocardial motion in corresponding views of the two sections.

RESULTS

Comparing the myocardial motion between the lateral wall's basal segment in the apical four-chamber view of the LV and the lateral wall of the PMV-level short-axis view revealed that the Vd was positively correlated (r = 0.59, p<0.01), as was SRs (r = 0.68, p<0.05). Comparing the myocardial motion between the lateral wall's middle segment in the apical four-chamber view of the LV and the lateral wall of the PMV-level short-axis view demonstrated that Vd, SRs, and SRd were positively correlated (r = 0.63, 0.82, 0.79, respectively, all p<0.01). Our comparison of myocardial motion between the posterior septum's basal segment in the apical four-chamber view of the LV and the posterior septum of PMV-level short-axis view showed that Vd and SRs were positively correlated (r = 0.57, 0.68, respectively, both p<0.01). Comparing the myocardial motion between the posterior septum's middle segment in the apical four-chamber view of the LV and the posterior septum of the PMV-level short-axis view revealed that Vs, Vd, SR, and SRd were positively correlated (r = 0.89, 0.63, 0.64, 0.6, respectively, all p<0.01), and the SRs also had a significant positive correlation (r = 0.53, p<0.05).

CONCLUSION

VVI technology could be a valuable tool for evaluating the myocardial walls motion of the apical four-chamber view of the rat LV.

Prognostic value of heart failure echocardiography index in HF patients with preserved, mid-ranged and reduced ejection fraction

Background

To investigate the clinical value of heart failure echocardiography index (HFEI) in evaluating the cardiac function and predicting the prognosis of patients with different types of heart failure (HF).

Methods

Four hundred eighty-nine consecutively admitted HF patients were divided into three groups: HF with reduced ejection (HFrEF), HF with mid-range ejection fraction (HFmrEF), and HF with preserved ejection fraction (HFpEF). The baseline characteristics and ultrasound indexes were compared between the three groups. The correlation between HFEI and one-year risk of adverse events was compared by multivariate logistic regression. The clinical value of HFEI and plasma level of NT-proBNP in assessing the prognosis of patients with chronic heart failure (CHF) was analyzed by the receiver operating characteristic (ROC) curve.

Results

HFEI in HFrEF was significantly higher than that in HFmrEF and HFpEF. Multivariate regression analysis indicated that HFEI and plasma level of NT-proBNP were independent risk factors for predicting the short-time prognosis of HF patients. The ROC curve indicated that the HFEI cutoff level of 3.5 and the plasma NT-proBNP level of 3000 pg/ml predicted a poor prognosis of CHF patients with a sensitivity of 64% and a specificity of 75% vs. 68 and 65%.

Conclusion

HFEI can comprehensively evaluate the overall cardiac function of patients with various types of HF, and may prove to be an important index of assessing the prognosis of HF patients.

Left Ventricular Systolic Function in Patients with Systemic Lupus Erythematosus and Its Association with Cardiovascular Events

BACKGROUND

Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder with potential cardiovascular involvement. The aim of this study was to assess left ventricular (LV) systolic function in a large cohort of patients with SLE using standard echocardiographic measurements and global longitudinal strain (GLS) by two-dimensional speckle-tracking analysis. Furthermore, the association between echocardiographic parameters and the occurrence of cardiovascular events was assessed.

METHODS

A total of 102 patients with SLE (88% women; mean age, 43 ± 14 years) undergoing a dedicated multidisciplinary assessment were analyzed, including echocardiography, at the time of their first visit. A control group consisted of 50 age- and sex-matched healthy subjects.

RESULTS

Compared with control subjects, patients with SLE showed impaired LV systolic function on the basis of LV ejection fraction (51 ± 6% vs 62 ± 6%, P < .001) and by LV GLS (-15 ± 3% vs -19 ± 2%, P < .001). During a median follow-up period of 2 years (interquartile range, 1-6 years), 38 patients (37%) developed cardiovascular events. Kaplan-Meier survival curves showed that patients with SLE with more impaired LV GLS (on the basis of the median value of -15%) experienced higher cumulative rates of cardiovascular events compared with those with less impaired LV GLS (χ² = 8.292, log-rank P = .004). On multivariate Cox regression analysis, LV GLS demonstrated an independent association with cardiovascular events (hazard ratio, 2.171; 95% CI, 1.015-4.642; P = .046), whereas LV ejection fraction was not significantly associated with the outcome.

CONCLUSIONS

In patients with SLE, LV systolic function as measured by LV GLS is significantly impaired and associated with cardiovascular events, potentially representing a new tool to improve risk stratification in these patients.

Predicting High-Risk Patients and High-Risk Outcomes in Heart Failure

Identifying patients with heart failure at high risk for poor outcomes is important for patient care, resource allocation, and process improvement. Although numerous risk models exist to predict mortality, hospitalization, and patient-reported health status, they are infrequently used for several reasons, including modest performance, lack of evidence to support routine clinical use, and barriers to implementation. Artificial intelligence has the potential to enhance the performance of risk prediction models, but has its own limitations and remains unproved.

Phenotyping Heart Failure According to the Longitudinal Ejection Fraction Change: Myocardial Strain, Predictors, and Outcomes

Background

Many patients with heart failure (HF) experience changes in left ventricular ejection fraction (LVEF) during follow‐up. We sought to evaluate the predictors and outcomes of different HF phenotypes according to longitudinal changes in EF.

Methods and Results

A total of 2104 patients with acute HF underwent echocardiography at baseline and follow‐up. Global longitudinal strain was measured at index admission. HF phenotypes were defined as persistent HF with reduced EF (persistent HFrEF, LVEF ≤40% at baseline and follow‐up), heart failure with improved ejection fraction (LVEF≤40% at baseline and improved to >40% at follow‐up), heart failure with declined ejection fraction (LVEF>40% at baseline and declined to ≤40% at follow up), and persistent HF with preserved EF (persistent HFpEF, LVEF>40% at baseline and follow‐up). Overall, 1130 patients had HFrEF at baseline; during follow‐up, 54.2% and 46.8% had persistent HFrEF and heart failure with improved ejection fraction, respectively. Among 975 patients with HFpEF at baseline, 89.5% and 10.5% had persistent HFpEF and heart failure with declined ejection fraction at follow‐up, respectively. The 5‐year all‐cause mortality rates were 43.1%, 33.1%, 24%, and 17% for heart failure with declined ejection fraction, persistent HFrEF, persistent HFpEF, and heart failure with improved ejection fraction, respectively (global log‐rank P<0.001). In multivariable analyses, each 1% increase in global longitudinal strain (greater contractility) was associated with 10% increased odds for heart failure with improved ejection fraction among patients with HFrEF at baseline and 7% reduced odds for heart failure with declined ejection fraction among patients with HFpEF at baseline.

Conclusions

LVEF changed during follow‐up. Each HF phenotype according to longitudinal LVEF changes has a distinct prognosis. Global longitudinal strain can be used to predict the HF phenotype.

REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03513653.

Ventricular strain analysis in patients with no structural heart disease using a vendor-independent speckle-tracking software

Background

Ventricular strain measurements vary depending on cardiac chamber (left ventricle [LV] or right ventricle [RV]), type of strain (longitudinal, circumferential, or radial), ventricular level (basal, mid, or apical), myocardial layer (endocardial or epicardial), and software used for analysis, among other demographic factors such as age and gender. Here, we present an analysis of ventricular strain taking all of these variables into account in a cohort of patients with no structural heart disease using a vendor-independent speckle-tracking software.

Methods

LV and RV full-thickness strain parameters were retrospectively measured in 102 patients (mean age 39 ± 15 years; 62% female). Within this cohort, we performed further layer-specific strain analysis in 20 subjects. Data were analyzed for global and segmental systolic strain, systolic strain rate, early diastolic strain rate, and their respective time-to-peak values.

Results

Mean LV global longitudinal, circumferential, and radial strain values for the entire cohort were − 18.4 ± 2.0%, − 22.1 ± 4.1%, and 43.9 ± 12.1% respectively, while mean RV global and free wall longitudinal strain values were − 24.2 ± 3.9% and − 26.1 ± 5.2% respectively. Women on average demonstrated higher longitudinal and circumferential strain and strain rate than men, and longer corresponding time-to-peak values. Longitudinal strain measurements were highest at the apex compared with the mid ventricle and base, and in the endocardium compared with the epicardium. Longitudinal strain was the most reproducible measure, followed closely by circumferential strain, while radial strain showed suboptimal reproducibility.

Conclusions

We present an analysis of ventricular strain in patients with no structural heart disease using a vendor-independent speckle-tracking software.

Global longitudinal strain is associated with better outcomes in transcatheter aortic valve replacement

Background

Parameters that mark the timing of left ventricular (LV) reverse remodeling following transcatheter aortic valve replacement (TAVR) are incompletely defined. This study aims to identify the dynamics of LV strain derived from speckle tracking echocardiography in a cohort of patients with severe aortic stenosis (AS) who underwent TAVR and its correlation with postprocedural outcomes.

Methods

We selected 150 consecutive patients (82 ± 4 years old, STS score 6.4 ± 6.2) who underwent transfemoral TAVR between 07/2016 and 12/2017 at our tertiary care center. All patients were evaluated at baseline, 1 week after TAVR, and 3 months following TAVR.

Results

The global longitudinal strain (GLS) 1 week following TAVR was comparable to that at baseline (− 15,9 ± 4.3 vs − 16.8 ± 4.1; p = NS) but significantly improved at 3 months following TAVR (− 15.9 ± 4.3% vs. -19.5 ± 3.5%; p < 0.001). No significant changes in global circumferential strain (GCS) and global radial strain (GRS) were detectable. The ejection fraction was significantly improved 1 week after the TAVR procedure. The baseline GLS correlated directly with the complication rate (R = 0.36, p = 0.005). The linear regression analysis showed that the main predictors of the improvement in the GLS at 3 months in our cohort were baseline GRS and GCS.

Conclusion

GLS improves at 3 months after TAVR, while LV ejection fraction does not show a substantial change, signaling an early recovery of LV longitudinal function after the intervention. Additionally, GLS has a direct correlation with the postprocedural outcomes. GLS improvement might emerge as a valuable parameter for a tailored follow-up in TAVR patients.

Changes in Myocardial Microstructure and Mechanics With Progressive Left Ventricular Pressure Overload

This study assessed the regional changes in myocardial geometry, microstructure, mechanical behavior, and properties that occur in response to progressive left ventricular pressure overload (LVPO) in a large animal model. Using an index of local biomechanical function at early onset of LVPO allowed for prediction of the magnitude of left ventricular chamber stiffness (Kc) and left atrial area at LVPO late timepoints. Our study found that LV myocardial collagen content alone was insufficient to identify mechanisms for LV myocardial stiffness with progression to heart failure with preserved ejection fraction (HFpEF). Serial assessment of regional biomechanical function might hold value in monitoring the natural history and progression of HFpEF, which would allow evaluation of novel therapeutic approaches.

Right Ventricular Strain Impairment in Adults and Adolescents with Repaired Aortic Coarctation

This study examines the function of the right ventricle (RV) using two-dimensional (2D) strain analysis after aortic coarctation (CoA) repair, as well as relationships between potential RV strain abnormalities and patient characteristics. The study examined 39 patients (61% male, age 32 ± 16 years) with CoA repair (33 post end-to-end anastomosis/sub-clavian flap, 6 post stenting/bypass/Teflon patch) and 42 controls. The structure and function of the left ventricle (LV), left atrium (LA), and RV were assessed using 2D standard echocardiography, tissue Doppler imaging, and 2D strain imaging. The characteristics examined included global RV longitudinal strain (RV-GLS), global LV longitudinal strain (LV-GLS), and LA longitudinal strain (LA strain). RV dysfunction was defined by RV-GLS lower than the mean minus 2 standard deviations (SDs) of the control group value. LV mass and mitral E/E_a were significantly higher in the CoA group. Septal E_a, LV-GLS, and LA strain were significantly lower in the CoA group. RV dysfunction (RV-GLS >  - 16%) was present in 10 (25.6%) CoA patients. RV-GLS was correlated with lateral E_a, LV-GLS, and LA strain (r =  - 0.35, p = 0.02; r =  - 0.54, p < 0.001; and r =  - 0.44, p = 0.005, respectively). Patients who had a stenting/bypass/Teflon patch as the first initial repair exhibited significantly lower RV-GLS. RV systolic strain abnormalities may occur in patients late after CoA repair. RV strain was correlated with parameters of LV dysfunction. Further large-scale studies are required to confirm these findings and to determine the mechanisms and prognostic implications of RV strain in such patients.

Research Priorities for Heart Failure With Preserved Ejection Fraction: National Heart, Lung, and Blood Institute Working Group Summary

Heart failure with preserved ejection fraction (HFpEF), a major public health problem that is rising in prevalence, is associated with high morbidity and mortality and is considered to be the greatest unmet need in cardiovascular medicine today because of a general lack of effective treatments. To address this challenging syndrome, the National Heart, Lung, and Blood Institute convened a working group made up of experts in HFpEF and novel research methodologies to discuss research gaps and to prioritize research directions over the next decade. Here, we summarize the discussion of the working group, followed by key recommendations for future research priorities. There was uniform recognition that HFpEF is a highly integrated, multiorgan, systemic disorder requiring a multipronged investigative approach in both humans and animal models to improve understanding of mechanisms and treatment of HFpEF. It was recognized that advances in the understanding of basic mechanisms and the roles of inflammation, macrovascular and microvascular dysfunction, fibrosis, and tissue remodeling are needed and ideally would be obtained from (1) improved animal models, including large animal models, which incorporate the effects of aging and associated comorbid conditions; (2) repositories of deeply phenotyped physiological data and human tissue, made accessible to researchers to enhance collaboration and research advances; and (3) novel research methods that take advantage of computational advances and multiscale modeling for the analysis of complex, high-density data across multiple domains. The working group emphasized the need for interactions among basic, translational, clinical, and epidemiological scientists and across organ systems and cell types, leveraging different areas or research focus, and between research centers. A network of collaborative centers to accelerate basic, translational, and clinical research of pathobiological mechanisms and treatment strategies in HFpEF was discussed as an example of a strategy to advance research progress. This resource would facilitate comprehensive, deep phenotyping of a multicenter HFpEF patient cohort with standardized protocols and a robust biorepository. The research priorities outlined in this document are meant to stimulate scientific advances in HFpEF by providing a road map for future collaborative investigations among a diverse group of scientists across multiple domains.

The Use of Echocardiography and Advanced Cardiac Ultrasonography During Pregnancy

PURPOSE OF REVIEW

Pregnancy is a time of significant cardiovascular change. Echocardiography is the primary imaging modality used to assess cardiovascular anatomy and physiology during pregnancy. Both two-dimensional (2D) echocardiography and advanced cardiac ultrasound modalities play pivotal roles in identifying and monitoring these changes, especially in women with preexisting or new cardiac disease. This paper reviews the role of echocardiography and advanced cardiac ultrasound during normal pregnancy and pregnancy complicated by hypertensive disorders, valvular disorders, and cardiomyopathy. It also examines the role of echocardiography in guiding decisions about delivery.

RECENT FINDINGS

The data establishing normal echo parameters during pregnancy are inconsistent. In addition, there is limited research exploring the role of advanced cardiac ultrasound modalities, such as tissue Doppler imaging or speckle tracking echocardiography, in assessing cardiac function during pregnancy. What data there are suggest that these advanced modalities can be used to identify subclinical changes before traditional echocardiography can, and thus have clear utility in identifying early abnormal cardiac responses to pregnancy. Echocardiography is the modality of choice for imaging the heart in pregnant women. Advanced ultrasound modalities increasingly play a role in identifying abnormal adaptations to pregnancy and detecting subclinical changes. This, in turn, can help promote a healthy pregnancy for both mother and fetus.

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

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

Use of speckle tracking to assess heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) currently represents approximately 50% of heart failure (HF) cases in the USA and is increasingly recognized as a leading cause of morbidity and mortality. Recent data suggest that the prevalence of HFpEF relative to HF with reduced ejection fraction (HFrEF) is increasing at a rate of 1% per year. With an aging population and increasing risk factors such as hypertension, obesity, and diabetes mellitus, HFpEF will soon be the most prevalent HF phenotype. Two-dimensional speckle-tracking echocardiography (STE) has been used to diagnose HFpEF specifically by focusing on the longitudinal systolic function of the left ventricle (LV). Yet there are many patients with HFpEF in whom there are no differences in LV global longitudinal systolic strain, but there are changes in left atrial function and structure. There are several proposed pathophysiological mechanisms for HFpEF such as endothelial dysfunction, interactions among proteins, signaling pathways, and myocardial bioenergetics. Yet only one specific therapy, mineralocorticoid receptor antagonist, spironolactone, is recommended as a treatment for patients with HFpEF. However, spironolactone does not address many of the pathophysiologic changes that occur in HFpEF, thus new novel therapeutic agents are needed. With the limited available therapies, clinicians should use STE to assess for the presence of this syndrome in their patients to provide effective diagnosis and management.

Effect of Neladenoson Bialanate on Exercise Capacity Among Patients With Heart Failure With Preserved Ejection Fraction: A Randomized Clinical Trial

IMPORTANCE

Heart failure with preserved ejection fraction (HFpEF) lacks effective treatments. Based on preclinical studies, neladenoson bialanate, a first-in-class partial adenosine A1 receptor agonist, has the potential to improve several heart failure-related cardiac and noncardiac abnormalities but has not been evaluated to treat HFpEF.

OBJECTIVES

To determine whether neladenoson improves exercise capacity, physical activity, cardiac biomarkers, and quality of life in patients with HFpEF and to find the optimal dose.

DESIGN, SETTING, AND PARTICIPANTS

Phase 2b randomized clinical trial conducted at 76 centers in the United States, Europe, and Japan. Patients (N = 305) with New York Heart Association class II or III HFpEF with elevated natriuretic peptide levels were enrolled between May 10, 2017, and December 7, 2017 (date of final follow-up: June 20, 2018).

INTERVENTIONS

Participants were randomized (1:2:2:2:2:3) to neladenoson (n = 27 [5 mg], n = 50 [10 mg], n = 51 [20 mg], n = 50 [30 mg], and n = 51 [40 mg]) or matching placebo (n = 76) for 20 weeks of treatment.

MAIN OUTCOMES AND MEASURES

The primary end point was change in 6-minute walk test distance from baseline to 20 weeks (minimal clinically important difference, 40 m). Key safety measures included bradyarrhythmias and adverse events. To evaluate the effects of varying doses of neladenoson, a multiple comparison procedure with 5 modeling techniques (linear, Emax, 2 variations of sigmoidal Emax, and quadratic) was used to evaluate diverse dose-response profiles.

RESULTS

Among 305 patients who were randomized (mean age, 74 years; 160 [53%] women; mean 6-minute walk test distance, 321.5 m), 261 (86%) completed the trial and were included in the primary analysis. After 20 weeks of treatment, the mean absolute changes from baseline in 6-minute walk test distance were 0.2 m (95% CI, -12.1 to 12.4 m) for the placebo group; 19.4 m (95% CI, -10.8 to 49.7 m) for the 5 mg of neladenoson group; 29.4 m (95% CI, 3.0 to 55.8 m) for 10 mg of neladenoson group; 13.8 m (95% CI, -2.3 to 29.8 m) for 20 mg of neladenoson group; 16.3 m (95% CI, -1.1 to 33.6 m) for 30 mg of neladenoson group; and 13.0 m (95% CI, -5.9 to 31.9 m) for 40 mg of neladenoson group. Because none of the neladenoson groups achieved the clinically relevant 40-m increase in 6-minute walk test distance from baseline, an optimal dose of neladenoson was not identified. There was no significant dose-response relationship for the change in 6-minute walk test distance among the 5 different dose-response models (P = .05 for Emax; P = .18 for quadratic; P = .21 for sigmoidal Emax 1; P = .39 for linear; and P = .52 for sigmoidal Emax 2). Serious adverse events were similar among the neladenoson groups (61/229 [26.6%]) and the placebo group (21/76 [27.6%]).

CONCLUSIONS AND RELEVANCE

Among patients with HFpEF, there was no significant dose-response relationship detected for neladenoson with regard to the change in exercise capacity from baseline to 20 weeks. In light of these findings, novel approaches will be needed if further development of neladenoson for the treatment of patients with HFpEF is pursued.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03098979.