Left ventricular ejection fraction in heart failure: a clinician's perspective about a dynamic and imperfect parameter, though still convenient and a cornerstone for patient classification and management

Prognostic impact of prior LVEF in patients with heart failure with mildly reduced ejection fraction

AIMS

As there is limited evidence regarding the prognostic impact of prior left ventricular ejection fraction (LVEF) in patients with heart failure with mildly reduced ejection fraction (HFmrEF), this study investigates the prognostic impact of longitudinal changes in LVEF in patients with HFmrEF.

METHODS

Consecutive patients with HFmrEF (i.e. LVEF 41-49% with signs and/or symptoms of HF) were included retrospectively in a monocentric registry from 2016 to 2022. Based on prior LVEF, patients were categorized into three groups: stable LVEF, improved LVEF, and deteriorated LVEF. The primary endpoint was 30-months all-cause mortality (median follow-up). Secondary endpoints included in-hospital and 12-months all-cause mortality, as well as HF-related rehospitalization at 12 and 30 months. Kaplan-Meier and multivariable Cox proportional regression analyses were applied for statistics.

RESULTS

Six hundred eighty-nine patients with HFmrEF were included. Compared to their prior LVEF, 24%, 12%, and 64% had stable, improved, and deteriorated LVEF, respectively. None of the three LVEF groups was associated with all-cause mortality at 12 (p ≥ 0.583) and 30 months (31% vs. 37% vs. 34%; log rank p ≥ 0.376). In addition, similar rates of 12- (p ≥ 0.533) and 30-months HF-related rehospitalization (21% vs. 23% vs. 21%; log rank p ≥ 0.749) were observed. These findings were confirmed in multivariable regression analyses in the entire study cohort.

CONCLUSION

The transition from HFrEF and HFpEF towards HFmrEF is very common. However, prior LVEF was not associated with prognosis, likely due to the persistently high dynamic nature of LVEF in the follow-up period.

Assessment of left ventricular ejection fraction in artificial intelligence based on left ventricular opacification

Background

Left ventricular opacification (LVO) improves the accuracy of left ventricular ejection fraction (LVEF) by enhancing the visualization of the endocardium. Manual delineation of the endocardium by sonographers has observer variability. Artificial intelligence (AI) has the potential to improve the reproducibility of LVO to assess LVEF.

Objectives

The aim was to develop an AI model and evaluate the feasibility and reproducibility of LVO in the assessment of LVEF.

Methods

This retrospective study included 1305 echocardiography of 797 patients who had LVO at the Department of Ultrasound Medicine, Union Hospital, Huazhong University of Science and Technology from 2013 to 2021. The AI model was developed by 5-fold cross validation. The validation datasets included 50 patients prospectively collected in our center and 42 patients retrospectively collected in the external institution. To evaluate the differences between LV function determined by AI and sonographers, the median absolute error (MAE), spearman correlation coefficient, and intraclass correlation coefficient (ICC) were calculated.

Results

In LVO, the MAE of LVEF between AI and manual measurements was 2.6% in the development cohort, 2.5% in the internal validation cohort, and 2.7% in the external validation cohort. Compared with two-dimensional echocardiography (2DE), the left ventricular (LV) volumes and LVEF of LVO measured by AI correlated significantly with manual measurements. AI model provided excellent reliability for the LV parameters of LVO (ICC > 0.95).

Conclusions

AI-assisted LVO enables more accurate identification of the LV endocardium and reduces observer variability, providing a more reliable way for assessing LV function.

Effects of Hypertrophic and Dilated Cardiac Geometric Remodeling on Ejection Fraction

Background: Both heart failure (HF) with preserved ejection fraction (HFpEF) and heart failure with reduced ejection fraction (HFrEF) can present a wide variety of cardiac morphologies consequent to cardiac remodeling. We sought to study if geometric changes to the heart during such remodeling will adversely affect the ejection fraction (EF) parameter’s ability to serve as an indicator of heart function, and to identify the mechanism for it.

Methods and Results: A numerical model that simulated the conversion of myocardial strain to stroke volume was developed from two porcine animal models of heart failure. Hypertrophic wall thickening was found to elevate EF, while left ventricle (LV) dilation was found to depress EF when myocardial strain was kept constant, causing EF to inaccurately represent the overall strain function. This was caused by EF being calculated using the endocardial boundary rather than the mid-wall layer. Radial displacement of the endocardial boundary resulted in endocardial strain deviating from the overall LV strain, and this deviation varied with LV geometric changes. This suggested that using the epi- or endo-boundaries to calculate functional parameters was not effective, and explained why EF could be adversely affected by geometric changes. Further, when EF was modified by calculating it at the mid-wall layer instead of at the endocardium, this shortcoming was resolved, and the mid-wall EF could differentiate between healthy and HFpEF subjects in our animal models, while the traditional EF could not.

Conclusion: We presented the mechanism to explain why EF can no longer effectively indicate cardiac function during cardiac geometric changes relevant to HF remodeling, losing the ability to distinguish between hypertrophic diseased hearts from healthy hearts. Measuring EF at the mid-wall location rather than endocardium can avoid the shortcoming and better represent the cardiac strain function.

A multidisciplinary approach to heart failure care in the hospital: improving the patient journey

Despite advancements in care for patients with heart failure (HF), morbidity and mortality remain high. Hospitalizations and readmissions for HF have been the focus of significant attention among health care providers and payers, with an eye towards reducing health care costs. However, considerable variability exists with regard to inpatient workflows and management for patients with HF, which represents a significant opportunity to improve care. Here we provide a summary of optimal inpatient management strategies for HF, focusing on the multidisciplinary team of emergency medicine providers, admitting hospitalists, cardiovascular consultants, pharmacists, nurses, and social workers. The patient journey serves as the template for this review article, from the initial presentation in the emergency department, to decongestion and stabilization, optimization of guideline-directed medical therapy, and discharge and appropriate disposition. Lastly, this review aims not to be proscriptive but rather to provide best practices that are clinically relevant and actionable, with the goal of improving care for patients during the sentinel hospitalization for HF.

The Effect of Low Preoperative Ejection Fraction on Mortality After Cardiac Surgery in Indonesia

Background

Among cardiac surgery patients, low preoperative left ventricular ejection fraction (LVEF) is common and has been associated with poor outcomes. The objective of this study was to assess the association between LVEF and postoperative mortality in patients undergoing open-heart surgery in several hospitals in Indonesia.

Methods

We conducted a multicenter study with the retrospective design using data from patients undergoing open-heart surgery in 4 institutions in Indonesia. Data regarding LVEF and other potential risk factors were extracted from medical records and compiled in one datasheet. Statistical analyses were performed to assess if low LVEF was associated with postoperative mortality and identify other potential risk factors.

Results

A total of 4789 patients underwent cardiac surgery in participating centers during the study period. Of these, 189 subjects (3.9%) had poor preoperative LVEF. Poor LVEF was associated with postoperative mortality (adjusted OR 2.761, 95% CI 1.763–4.323, p < 0.001). Based on types of surgery, LVEF had a significant association with mortality only in CABG patients, while there was no such association in valve surgery and inconclusive in congenital surgery patients. Other significant independent predictors of in-hospital mortality included age more than 65 years old, non-elective surgery, the complexity of procedures, history of cardiac surgery, organ failure, CARE score ≥ 3, NYHA class ≥ III, and poor right ventricular function.

Conclusion

Patients with low preoperative LVEF undergoing open-heart surgery had a higher risk of postoperative mortality. Cardiac surgery can be performed with acceptable mortality rates. Accurate selection of patients, risk/benefit evaluation, and planning of surgical and anesthesiological management are mandatory to improve outcomes.

Rationale and design of the preserved versus reduced ejection fraction biomarker registry and precision medicine database for ambulatory patients with heart failure (PREFER-HF) study

INTRODUCTION

Patients with heart failure (HF) are classically categorised by left ventricular ejection fraction (LVEF). Efforts to predict outcomes and response to specific therapy among LVEF-based groups may be suboptimal, in part due to the underlying heterogeneity within clinical HF phenotypes. A multidimensional characterisation of ambulatory patients with and without HF across LVEF groups is needed to better understand and manage patients with HF in a more precise manner.

METHODS AND ANALYSIS

To date, the first cohort of 1313 out of total planned 3000 patients with and without HF has been enroled in this single-centre, longitudinal observational cohort study. Baseline and 1-year follow-up blood samples and clinical characteristics, the presence and duration of comorbidities, serial laboratory, echocardiographic data and images and therapy information will be obtained. HF diagnosis, aetiology of disease, symptom onset and clinical outcomes at 1 and 5 years will be adjudicated by a team of clinicians. Clinical outcomes of interest include all-cause mortality, cardiovascular mortality, all-cause hospitalisation, cardiovascular hospitalisation, HF hospitalisation, right-sided HF and acute kidney injury. Results from the Preserved versus Reduced Ejection Fraction Biomarker Registry and Precision Medicine Database for Ambulatory Patients with Heart Failure (PREFER-HF) trial will examine longitudinal clinical characteristics, proteomic, metabolomic, genomic and imaging data to better understand HF phenotypes, with the ultimate goal of improving precision medicine and clinical outcomes for patients with HF.

ETHICS AND DISSEMINATION

Information gathered in this research will be published in peer-reviewed journals. Written informed consent for PREFER-HF was obtained from all participants. All study procedures were approved by the Mass General Brigham Institutional Review Board in Boston, Massachusetts and performed in accordance with the Declaration of Helsinki (Protocol Number: 2016P000339).

TRIAL REGISTRATION NUMBER

PREFER-HF ClinicalTrials.gov identifier: NCT03480633.

Left ventricular function monitoring in heart failure

Imaging modalities are used for screening, risk stratification and monitoring of heart failure (HF). In particular, echocardiography represents the cornerstone in the assessment of left ventricular (LV) dysfunction. Despite the well-known limitations of LV ejection fraction, this parameter, repeated assessment of LV function is recommended for the diagnosis and care of patients with HF and provides prognostic information. Left ventricular ejection fraction (LVEF) has an essential role in phenotyping and appropriate guiding of the therapy of patients with chronic HF. This document reflects the key points concerning monitoring LV function discussed at a consensus meeting on physiological monitoring in the complex multi-morbid HF patient under the auspices of the Heart Failure Association of the ESC.

A bio-clinical approach for prediction of sudden cardiac death in outpatients with heart failure: The ST2-SCD score

BACKGROUND

Sudden cardiac death (SCD) is one of the main modes of death in heart failure (HF) patients and its prediction remains a real challenge. Our aim was to assess the incidence of SCD at 5 years HF contemporary managed outpatients, and to find a simple prediction model for SCD.

METHODS

SCD was considered any unexpected death, witnessed or not, occurring in a previously stable patient with no evidence of worsening HF or any other cause of death. A competing risk strategy was adopted using the Fine-Gray method of Cox regressions analyses that considered other causes of death as the competing event.

RESULTS

The derivation cohort included 744 consecutive outpatients (72% men, age 67.9 ± 12.2 years, left ventricular ejection fraction [LVEF] 36% ± 14). During follow-up, 312 deaths occurred, 40 SCDs (5.4%). Age, haemoglobin, eGFR, HF duration, high-sensitivity troponin T, NTproBNP, and ST2 were associated with SCD in univariate analyses; HF duration (p = 0.006), eGFR (p < 0.001), LVEF <45% (p = 0.03), and ST2 (p = 0.006) remained in multivariable analysis. A predictive score (ST2-SCD) including dichotomous variables (ST2 > 45, LVEF <45%, HF duration >3 years, eGFR < 55, age ≥ 60 years and male sex) provided a Harrell's C-statistic of 0.82 (0.76-0.89)), reaching 0.87 (0.80-0.95) in the validation cohort (n = 149).

CONCLUSIONS

In contemporary managed HF, SCD occurred in 5.4% of outpatients, accounting for 12.8% of all deaths at 5 years. Of the 3 studied biomarkers, only ST2 remained independently associated with SCD. A model containing age, sex, ST2, eGFR, LVEF, and HF duration reasonably predicted 5-years risk of SCD.

Left Ventricular Ejection Fraction in Heart Failure

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Heart failure with mid-range ejection fraction: are there clinical reasons in introduction of this new group as a distinct entity?

The article discusses the clinical expedience of isolating into a separate classification subgroup of patients with heart failure and a mid‑range ejection fraction (EF) of 40-49 %. Analysis of studies 2017-2018 focusing on the issue of patients with mid‑range LV EF showed that this subgroup is highly heterogenous and by some clinical and demographic parameters takes an intermediate position between heart failure (HF) patients with reduced (&lt;40 %) and preserved (&gt;50 %) LV EF. However, patients with mid‑range LV EF positively respond to beta‑blocker and RAAS inhibitor therapy, and their response is close to that of patients with reduced LV EF. This is a principal difference between patients with mid‑range and preserved LV EF who generally do not display any beneficial effect of such therapy. One of the major causes for such difference is a dissimilarity of HF etiology and, hence, pathogenesis in patients with reduced and mid‑range LV EF: primarily IHD (so‑called "ischemic" phenotype) in patients with reduced and mid‑range LV EF and non‑cardiac causes ("non‑ischemic" phenotype) in patients with preserved LV EF. Since the nonischemic phenotype is also rather common among patients with mid‑range LV EF a new HF classification should definitely indicate, in addition to LV EF, the clinical phenotype of disease, which is particularly important for patients with mid‑range LV EF of 40-49 %. Further studies should focus on variants of HF clinical phenotypes.