Diastology: 2020-A practical guide

20S-O-Glc-DM treats left ventricular diastolic dysfunction by modulating cardiomyocyte mitochondrial quality and excess autophagy

BACKGROUND

Left ventricular diastolic dysfunction (LVDD) is a manifestation of heart failure, with both its incidence and prevalence increasing annually. Currently, no pharmacological treatments are available for LVDD, highlighting the urgent need for new therapeutic discoveries. Ginsenosides are commonly used in cardiovascular therapy. Previous research has synthesized the ginsenoside precursor molecule, 20S-O-Glc-DM (C20DM), through biosynthesis. C20DM shows greater bioavailability, eco-friendliness, and cost-effectiveness compared to traditional ginsenosides, positioning it as a promising option for treating LVDD.

PURPOSE

This study firstly documents the therapeutic activity of C20DM against LVDD and unveils its potential mechanisms of action. It provides a pharmacological basis for C20DM as a new cardiovascular therapeutic agent.

METHODS

In this study, models of LVDD in mice and ISO-induced H9C2 cell damage were developed. Cell viability, ROS and Ca2+ levels, mitochondrial membrane potential, and proteins associated with mitochondrial biogenesis and autophagy were evaluated in the in vitro experiments. Animal experiments involved administering medication for 3 weeks to validate the therapeutic effects of C20DM and its impact on mitochondria and autophagy.

RESULTS

Research has shown that C20DM is more effective than Metoprolol in treating LVDD, significantly lowering the E/A ratio, e'/a' ratio, and IVRT, and ameliorating myocardial inflammation and fibrosis. C20DM influences the activity of PGC-1α, downregulates PINK1 and Parkin, thereby enhancing mitochondrial quality control, and restoring mitochondrial oxidative respiration and membrane potential. Furthermore, C20DM reduces excessive autophagy in cardiomyocytes via the AMPK-mTOR-ULK1 pathway, diminishing cardiomyocyte hypertrophy and damage.

CONCLUSIONS

Overall, our research indicates that C20DM has the potential to enhance LVDD through the regulation of mitochondrial quality control and cellular autophagy, making it a promising option for heart failure therapy.

Determinants and effects of microvascular obstruction on serial change in left ventricular diastolic function after reperfused acute myocardial infarction

Background

Although left ventricular (LV) diastolic dysfunction is more related to functional capacity after acute myocardial infarction (AMI), the determinants of LV diastolic functional change after reperfused AMI remain unknown. This study aimed to investigate the effects of microvascular obstruction (MVO) on mid-term changes in LV diastolic function after reperfused AMI.

Methods

In a cohort of 72 AMI patients who underwent successful revascularization, echocardiography and cardiovascular magnetic resonance imaging were repeated at 9-month intervals. The late gadolinium enhancement (LGE) amount, segmental extracellular volume fraction, global LV, and left atrial (LA) phasic functions, along with mitral inflow and tissue Doppler measurements, were repeated.

Results

Among the included patients, 31 (43%) patients had MVO. During the 9-month interval, LV ejection fraction (EF) and LV global longitudinal strain (GLS) were significantly improved in accordance with a decrease in LGE amount (from 18.2 to 10.3 g, p < 0.001) and LV mass. The deceleration time (DT) of early mitral inflow (188.6 ms-226.3 ms, p < 0.001) and LV elastance index (Ed; 0.133 1/ml-0.127 1/ml, p = 0.049) were significantly improved, but not in conventional diastolic functional indexes. Their improvements occurred in both groups; however, the degree was less prominent in patients with MVO. The degree of decrease in LGE amount and increase in LVEF was significantly correlated with improvement in LV-Ed or LA phasic function, but not with conventional diastolic functional indexes.

Conclusions

In patients with reperfused AMI, DT of early mitral inflow, phasic LA function, and LV-Ed were more sensitive diastolic functional indexes. The degree of their improvement was less prominent in patients with MVO.

Novel Strategies in Diagnosing Heart Failure with Preserved Ejection Fraction: A Comprehensive Literature Review

Heart failure (HF) with preserved ejection fraction (HFpEF) is a prevalent global condition affecting approximately 50% of the HF population. With the aging of the worldwide population, its incidence and prevalence are expected to rise even further. Unfortunately, until recently, no effective medications were available to reduce the high mortality and hospitalization rates associated with HFpEF, making it a significant unmet need in cardiovascular medicine. Although HFpEF is commonly defined as HF with normal ejection fraction and elevated left ventricular filling pressure, performing invasive hemodynamic assessments on every individual suspected of having HFpEF is neither feasible nor practical. Consequently, several clinical criteria and diagnostic tools have been proposed to aid in diagnosing HFpEF. Overall, these criteria and tools are designed to assist healthcare professionals in identifying and evaluating patients who may have HFpEF based on a combination of signs, symptoms, biomarkers, and non-invasive imaging findings. By employing these non-invasive diagnostic approaches, clinicians can make informed decisions regarding the best pharmacological and rehabilitation strategies for individuals with suspected HFpEF. This literature review aims to provide an overview of all currently available methods for diagnosing and monitoring this disabling condition.

Impact of an enhanced focused cardiac ultrasound on treatment changes in a population of internal medicine patients

BACKGROUND

Hospitalized patients with acute shortness of breath (SOB) could benefit from an enhanced focused cardiac ultrasound (eFoCUS) with Doppler measurements to reassess treatment and diagnosis.

METHODS

This was a retrospective observational study performed in a medical ward. Included patients were those hospitalized for acute SOB. The objectives were to assess therapeutic and diagnosis changes associated with eFoCUS. The primary endpoint of the analysis was a composite of introduction or discontinuation of diuretics, antibiotics or anticoagulation following eFoCUS.

RESULTS

Between January 2018 and July 2021, 119 patients were included, 67 women and 52 men, mean age 84 ± 11 years old. The eFoCUS was performed within a median time of 55 h (1st-3rd IQ: 21-107) following hospital admission. Overall, eFoCUS was associated with a change in diagnostic in 40 patients (34% [CI 95%: 25%-43%], p < 10-4 ) and a change in treatment in 53 patients (45% [CI 95%: 35%-54%], p < 10-4 ). Diuretics were prescribed in 94 patients before eFoCUS and in 56 after (p = 10-4 ), antibiotics in 34 before and 27 after and anticoagulation in 30 before and 40 after.

CONCLUSION

eFoCUS was associated with both therapeutic and diagnostic changes in patients with SOB. Such results should be confirmed in multicentric prospective studies.

Echocardiography to Assess Cardiac Structure and Function in Genetic Cardiomyopathies

Rodents are the most common experimental models used in cardiovascular research including studies of genetic cardiomyopathies. Genetic cardiomyopathies are characterized by changes in cardiac structure and function. Echocardiography allows for relatively inexpensive, non-invasive, reliable, and reproducible assessment of these changes. However, the fast heart and small size present unique challenges for investigators. To ensure accuracy and reproducibility of these measurements, investigators need to be familiar with standard practices in the field, normal values, and potential pitfalls. The goal of this chapter is to describe steps needed for reliable acquisition and analysis of echocardiography in rodent models. Additionally, we discuss some common pitfalls and challenges.

Left ventricular global longitudinal strain and cardiorespiratory fitness in patients with heart failure: Systematic review and meta-analysis

BACKGROUND

There is no definition for strain deformation values in relation to cardiorespiratory fitness (CRF) in different heart failure (HF) phenotypes.

AIM

To identify the relationship between echocardiographic systolic function measurements and CRF in HF patients.

METHODS

Systematic review and meta-analysis following the PRISMA recommendations. Studies reporting echocardiographic assessments of left ventricular global longitudinal strain (LVGLS), left ventricular ejection fraction (LVEF), and direct measurement of peak oxygen uptake (VO2peak) in HF patients with reduced or preserved LVEF (HFrEF, HFpEF) were included. The patients were divided into Weber classes according to VO2peak.

RESULTS

A total of 25 studies involving of 2,136 patients (70.5% with HFpEF) were included. Mean LVEF and LVGLS were similar in HFpEF patients in Weber Class A/B and Class C/D. In HFrEF patients, a non-significant difference was found in LVEF between Weber Class A/B (30.2% [95%CI: 29.6 to 30.9%]) and Class C/D (25.2% [95%CI: 20.5 to 29.9%]). In HFrEF patients, mean LVGLS was significantly lower in Class C/D compared to Class A/B (6.5% [95%CI: 6.0 to 7.1%] and 10.3% [95%CI: 9.0 to 11.5%], respectively). The correlation between VO2peak and LVGLS (r2 = 0.245) was nearly twofold stronger than that between VO2peak and LVEF (r2 = 0.137).

CONCLUSIONS

Low LVGLS values were associated with low CRF in HFrEF patients. Although a weak correlation was found between systolic function at rest and CRF, the correlation between VO2peak and LVGLS was nearly twofold stronger than that with LVEF, indicating that LVGLS may be a better predictor of CRF in patients with HFrEF.

Echocardiographic Evaluation of Diastolic Function in Special Populations

Left ventricular (LV) diastolic dysfunction results from a combination of impaired relaxation, reduced restoring forces, and increased chamber stiffness. Noninvasive assessment of diastology uses a multiparametric approach involving surrogate markers of increased filling pressures, which include mitral inflow, septal and lateral annular velocities, tricuspid regurgitation velocity, and left atrial volume index. However, these parameters must be used cautiously. This is because the traditional algorithms for evaluating diastolic function and estimation of LV filling pressures (LVFPs), as recommended by the American Society of Echocardiography and European Association of Cardiovascular Imaging 2016 guidelines, do not apply to unique patients with underlying cardiomyopathies, significant valvular disease, conduction abnormalities, arrhythmias, LV assist devices, and heart transplants, which alter the relation between the conventional indexes of diastolic function and LVFP. The purpose of this review is to provide solutions for evaluating LVFP through illustrative examples of these special populations, incorporating supplemental Doppler indexes, such as isovolumic relaxation time, mitral deceleration time, and pulmonary venous flow analysis, as needed to formulate a more comprehensive approach.

Expert proposal to characterize cardiac diseases with normal or preserved left ventricular ejection fraction and symptoms of heart failure by comprehensive echocardiography

Currently, the term "heart failure with preserved left ventricular ejection fraction (HFpEF)" is based on echocardiographic parameters and clinical symptoms combined with elevated or normal levels of natriuretic peptides. Thus, "HFpEF" as a diagnosis subsumes multiple pathophysiological entities making a uniform management plan for "HFpEF" impossible. Therefore, a more specific characterization of the underlying cardiac pathologies in patients with preserved ejection fraction and symptoms of heart failure is mandatory. The present proposal seeks to offer practical support by a standardized echocardiographic workflow to characterize specific diagnostic entities associated with "HFpEF". It focuses on morphological and functional cardiac phenotypes characterized by echocardiography in patients with normal or preserved left ventricular ejection fraction (LVEF). The proposal discusses methodological issues to clarify why and when echocardiography is helpful to improve the diagnosis. Thus, the proposal addresses a systematic echocardiographic approach using a feasible algorithm with weighting criteria for interpretation of echocardiographic parameters related to patients with preserved ejection fraction and symptoms of heart failure. The authors consciously do not use the diagnosis "HFpEF" to avoid misunderstandings. Central illustration: Scheme illustrating the characteristic echocardiographic phenotypes and their combinations in patients with "HFpEF" symptoms with respect to the respective cardiac pathology and pathophysiology as well as the underlying typical disease.

Subclinical HMOD in Hypertension: Left Ventricular Diastolic Dysfunction

Arterial hypertension represents an important risk factor for the development of cardiac, vascular and renal events, predisposing to heart failure, acute coronary syndromes, peripheral artery disease, stroke, and chronic renal disease. Arterial hypertension leads to the development of subclinical hypertension mediated organ damage (HMOD) which has prognostic relevance and may influence the choice of treatment options. Alterations of cardiac structure and function represent the more widely assessed form of HMOD. This manuscript will focus on the diagnostic opportunities, prognostic significance and treatment of diastolic dysfunction alterations.

Diagnostic role of echocardiography for patients with heart failure symptoms and preserved left ventricular ejection fraction

The syndrome heart failure with preserved ejection fraction (HFpEF) represents patients with different comorbidities and specific etiologies, but with a key and common alteration: an elevation in left ventricular (LV) filling pressure or pulmonary capillary wedge pressure (PCWP). Expert consensuses, society guidelines, and diagnostic scores have been stated to diagnose HFpEF syndrome based mainly on the determination of elevated LV filling pressure or PCWP by transthoracic echocardiography (TTE). Echocardiographic parameters such as early (E) and late diastolic mitral inflow velocity (mitral E/A ratio), septal and lateral mitral annular early diastolic velocity (E'), ratio of the early diastolic mitral inflow and annular velocity (E/E'-ratio), maximal left atrial volume index (LAVI_max), and tricuspid regurgitation peak velocity (V_TR) constitute the pivotal parameters for determining elevated LV filling pressure or PCWP in patients with suspected HFpEF symptoms. Notwithstanding this, taking into consideration the heterogeneity of patients with HFpEF symptoms, the term "HFpEF" should be considered as a syndrome rather than an entity since HFpEF results from different pathological entities that should and can be characterized by echocardiography and multimodality imaging. Comprehensive TTE might help diagnose specific diseases and etiologies by characterization of specific cardiac phenotypes.

Global longitudinal strain is superior to ejection fraction for detecting myocardial dysfunction in end-stage renal disease with hyperparathyroidism

BACKGROUND

The estimation of left ventricular ejection fraction (LVEF) by 2D echocardiography (2D-ECHO) is the most used tool to assess LV systolic function (LVSF). Global longitudinal strain (GLS) has recently been suggested as a superior method for several evaluations. This study explored the association and prevalence of LV systolic dysfunction (LVSD) by using these methods in patients with end-stage renal disease (ESRD) and severe hyperparathyroidism (SHPTH); both associated with cardiovascular events (CEs).

AIM

To evaluate the myocardial function in patients with ESRD and SHPTH by using the GLS and LVEF measured through conventional 2D-ECHO.

METHODS

In 62 patients with ESRD and SHPTH, asymptomatic, and without a history of CEs, LVSF was evaluated by 2D-ECHO, obtaining the EF, by the Simpson biplane method, and GLS by speckle tracking.

RESULTS

The total patients with ESRD had a preserved LVEF (> 50%) but abnormal GLS (< 13.55%). Additionally, multivariate analysis showed an independent association of GLS and serum parathyroid hormone (PTH), LV mass index, and hemoglobin. Also, PTH was independently associated with lateral e' wave and tricuspid regurgitation velocity.

CONCLUSION

In patients with SHPTH linked to ESRD, the use of GLS by 2D-ECHO is a more sensitive tool than LVEF for detecting LVSD.