Application of left ventricular strain in patients with aortic and mitral valve disease

Influence of chest wall conformation on reproducibility of main echocardiographic indices of left ventricular systolic function

BACKGROUND

The possible influence of chest wall conformation, as noninvasively assessed by Modified Haller Index (MHI, the ratio of chest transverse diameter over the distance between sternum and spine), on reproducibility of both left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS) has never been previously investigated.

METHODS

Two equal groups of healthy individuals, matched by age, sex, and cardiovascular risk factors and categorized according to MHI in those with concave-shaped chest wall (MHI>2.5) and those with normal chest shape (MHI≤2.5), who underwent transthoracic echocardiography implemented with echocardiographic deformation imaging between June 2018 and May 2019, were retrospectively analyzed. LVEF and GLS were measured twice by the two echocardiographers in a double blinded manner. Intra-class correlation coefficients (ICCs), bias and limits of agreement determined with Bland-Altman analysis were calculated for repeated measurements of both LVEF and GLS.

RESULTS

Thirty-four healthy individuals with MHI>2.5 (54.9±6.4 years, 58.8% females) and 34 matched controls with MHI≤2.5 (52.5±8.1 years, 50% females) were separately analyzed. In comparison to MHI≤2.5 group, the MHI>2.5 group was found with significantly smaller cardiac chambers and significantly lower GLS magnitude (-15.8±2.5 vs. -22.2±1.3%, P<0.001), despite similar LVEF (61.3±6.4 vs. 61.1±3.6%, P=0.87). In the MHI>2.5 group, intra-rater and inter-rater ICCs were ≤0.5 for both LVEF and LV-GLS, whereas in the MHI≤2.5 group intra-rater and inter-rater ICCs values indicated good reliability for LVEF and excellent reliability for GLS. The greatest bias and largest limits of agreement were detected for LVEF assessment (bias ranging from -1.09 to 2.94%, with the 95% limits of agreement ranging from -13.9 to 21.3%) in individuals with MHI>2.5. On the other hand, the smallest bias and narrowest limits of agreement were obtained for GLS measurement (bias ranging from -0.26 to 0.09%, with the 95% limits of agreement ranging from -1.4 to 1.4%) in participants with normal chest wall conformation (MHI≤2.5).

CONCLUSIONS

The test reliability of LVEF and GLS is strongly influenced by the chest wall conformation. MHI might represent an innovative approach for selecting the best echocardiographic method for LV systolic function estimation in the individual case.

Multimodality imaging for the global evaluation of aortic stenosis: The valve, the ventricle, the afterload

Aortic stenosis (AS) is the most common valvular heart disease growing in parallel to the increment of life expectancy. Besides the valve, the degenerative process affects the aorta, impairing its elastic properties and leading to increased systemic resistance. The composite of valvular and systemic afterload mediates ventricular damage. The first step of a thorough evaluation of AS should include a detailed assessment of valvular anatomy and hemodynamics. Subsequently, the ventricle, and the global afterload should be assessed to define disease stage and prognosis. Multimodality imaging is of paramount importance for the comprehensive evaluation of these three elements. Echocardiography is the cornerstone modality whereas Multi-Detector Computed Tomography and Cardiac Magnetic Resonance provide useful complementary information. This review comprehensively examines the merits of these imaging modalities in AS for the evaluation of the valve, the ventricle, and the afterload and ultimately endeavors to integrate them in a holistic assessment of AS.

Prognostic Value of Left Ventricular Global Longitudinal Strain for Major Adverse Cardiovascular Events in Patients with Aortic Valve Disease: A Meta-Analysis

INTRODUCTION

Valvular heart disease is one of the most common heart diseases. It is characterized by abnormal function or structure of the heart valves. There may be no clinical symptoms in the early stages. Clinical symptoms of arrhythmia, heart failure, or thromboembolic events may occur in the late stages of the disease, such as palpitation after activities, breathing difficulties, fatigue, and so on. Aortic valve disease is a major part of valvular heart disease. The main treatment for aortic valve disease is valve replacement or repair surgery, but it is extremely risky. Therefore, a rigorous prognostic assessment is extremely important for patients with aortic valve disease. The global longitudinal strain is an index that describes the deformation capacity of myocardium. There is evidence that it provides a test for systolic dysfunction other than LVEF (left ventricular ejection fraction) and provides additional prognostic information.

METHOD

Search literature published between 2010 and 2023 on relevant platforms and contain the following keywords: "Aortic valve disease," "Aortic stenosis," "Aortic regurgitation," and "longitudinal strain" or "strain." The data is then extracted and collated for analysis.

RESULTS

A total of 15 articles were included. The total population involved in this study was 3,678 individuals. The absolute value of LVGLS was higher in the no-MACE group than in the MACE group in patients with aortic stenosis (Z = 8.10, p < 0.00001), and impaired LVGLS was a risk factor for MACE in patients with aortic stenosis (HR = 1.14, p < 0.00001, 95% CI: 1.08-1.20). There was also a correlation between impaired LVGLS and aortic valve surgery in patients with aortic valve disease (HR = 1.16, p < 0.0001, 95% CI: 1.08-1.25) or patients with aortic valve regurgitation (HR = 1.21, p = 0.0004, 95% CI: 1.09-1.34). We also found that impaired LVGLS had no significant association between LVGLS and mortality during the period of follow-up in patients with aortic valve stenosis (HR = 1.08, 95% CI: 0.94-1.25, p = 0.28), but it was associated with mortality in studies of prospective analyses (HR = 1.34, 95% CI: 1.02-1.75, p = 0.04).

CONCLUSIONS

Impaired LVGLS correlates with major adverse cardiovascular events in patients with aortic valve disease, and it has predictive value for the prognosis of patients with aortic valve disease.

Prognostic Relevance of Left Ventricular Global Longitudinal Strain in Patients With Heart Failure and Reduced Ejection Fraction

Patients with heart failure (HF) and reduced ejection fraction (HFrEF) are complex patients who often have a high prevalence of co-morbidities and risk factors. In the present study, we investigated the prognostic significance of left ventricular (LV) global longitudinal strain (GLS) along with important clinical and echocardiographic variables in patients with HFrEF. Patients who had a first echocardiographic diagnosis of LV systolic dysfunction, defined as LV ejection fraction ≤45%, were selected. The study population was subdivided into 2 groups based on a spline curve analysis derived optimal threshold value of LV GLS (≤10%). The primary end point was occurrence of worsening HF, whereas the composite of worsening HF and all-cause death was chosen for the secondary end point. A total of 1,873 patients (mean age 63 ± 12 years, 75% men) were analyzed. During a median follow-up of 60 months (interquartile range 27 to 60 months), 256 patients (14%) experienced worsening HF and the composite end point of worsening HF and all-cause mortality occurred in 573 patients (31%). The 5-year event-free survival rates for the primary and secondary end point were significantly lower in the LV GLS ≤10% group compared with the LV GLS >10% group. After adjustment for important clinical and echocardiographic variables, baseline LV GLS remained independently associated with a higher risk of worsening HF (hazard ratio 0.95, 95% confidence interval 0.90 to 0.99, p = 0.032) and the composite of worsening HF and all-cause mortality (hazard ratio 0.94, 95% confidence interval 0.90 to 0.97, p = 0.001). In conclusion, baseline LV GLS is associated with long-term prognosis in patients with HFrEF, independent of various clinical and echocardiographic predictors.

Shifting from Left Ventricular Ejection Fraction to Strain Imaging in Aortic Stenosis

Adverse ventricular remodeling is an inflexion point of disease progression in aortic stenosis (AS) and a major determinant of prognosis. Intervention before irreversible myocardial damage is of paramount importance to sustain favorable post-operative outcomes. Current guidelines recommend a left ventricular ejection fraction (LVEF)-based strategy to determine the threshold for intervention in AS. However, LVEF has several pitfalls: it denotes the left ventricular cavity volumetric changes and it is not suited to detecting subtle signs of myocardial damage. Strain has emerged as a contemporary imaging biomarker that describes intramyocardial contractile force, providing information on subclinical myocardial dysfunction due to fibrosis. A large body of evidence advocates its use to determine the switch from adaptive to maladaptive myocardial changes in AS, and to refine thresholds for intervention. Although mainly studied in echocardiography, studies exploring the role of strain in multi-detector row computed tomography and cardiac magnetic resonance are emerging. This review, therefore, summarizes contemporary evidence on the role of LVEF and strain imaging in AS prognosis, aiming to move from an LVEF-based to a strain-based approach for risk stratification and therapeutic decision-making in AS.

Evaluation of left ventricular myocardial stratified strain in patients with Kawasaki disease using two-dimensional speckle tracking imaging

Kawasaki disease (KD) is an acute autoimmune self-limited disease of unknown etiology. We aimed to evaluate the left ventricular myocardial stratified strains in children with KD in different stages using two-dimensional speckle tracking imaging, and to find the index that can early predict myocardial function injury in children with KD. A total of 73 children with KD were divided into acute, convalescent, and chronic stages according to the disease course. All children had no coronary artery damage. Further, 64 normal children were selected as the control group. The longitudinal and circumferential strain peaks of each myocardium were recorded, and the left ventricular global longitudinal strain (LVGLS), global circumferential strain (LVGCS), and transmural gradient between endocardium and epicardium (ΔGLS, ΔGCS) were calculated. Compared with the control group, LVGLS, GLS-Endo, GLS-Mid, GLS-Epi, and ΔGLS decreased in acute KD; LVGLS, GLS-Endo, GLS-Mid, GLS-Epi, ΔGLS, LVGCS, GCS-Mid, and GCS-Epi decreased in the convalescent stage; and only GLS-Endo was lower in children with chronic KD (P < 0.05). ROC curve was used to calculate the stratified strain parameters so as to predict left ventricular systolic function in children with acute KD; the area under the LVGLS curve was the largest (AUC = 0.953, P < 0.001). When the cutoff value of LVGLS was −19.89%, the sensitivity and specificity were 95.8% and 83.2%, respectively.

Highlighting the role of global longitudinal strain assessment in valvular heart disease

Background

Echocardiography has been the choice for imaging modality for valvular heart disease. It is less invasive, widely available, and allows valvular structure visualization. Echocardiographic assessment often also determines the management. Left ventricular ejection fraction is the most commonly used indicator during echocardiography assessment. It shows signs of left ventricular dysfunction in patients with valve disease. However, most of the time, the ongoing process of cardiac damage may already occur even with preserved cardiac function; further deteriorated ejection fraction will show irreversible cardiac damage. There is a need for a more advanced diagnostic tool to detect early cardiac dysfunction, to prevent further damage.

Main body

Advanced echocardiography imaging using strain imaging allows a physician to evaluate cardiac function more precisely. A more sensitive parameter than left ventricular ejection fraction, global longitudinal strain, can evaluate subclinical myocardial dysfunction before the symptoms occur by evaluating complex cardiac mechanisms. Global longitudinal strain evaluation provides the chance for physicians to determine the intervention needed to prevent further deterioration and permanent cardiac dysfunction. Global longitudinal strain is proven to be beneficial in many types of valvular heart diseases, especially in mitral and aortic valve diseases. It has an excellent diagnostic and prognostic value for patients with valve disease. This review aims to present the superiority of global longitudinal strain compared to left ventricular ejection fraction in assessing cardiac function in patients with valvular heart disease. Clinical usage of global longitudinal strain in several valvular heart diseases is also presented in this review.

Conclusions

The superiority of global longitudinal strain to left ventricular ejection fraction relies on the mechanism where other strains would compensate for the deterioration of longitudinal strain, which is more vulnerable to damage, so the cardiac function is preserved. Therefore, examination of longitudinal strain would give the physician early signs of cardiac function impairment, and prompt management can be conducted.

Impaction of regurgitation jet on anterior mitral leaflet is associated with diastolic dysfunction in patients with bicuspid aortic valve and mild insufficiency: a cardiovascular magnetic resonance study

To assess the impact of regurgitant jet direction on left ventricular function and intraventricular hemodynamics in asymptomatic patients with bicuspid aortic valve (BAV) and mild aortic valve regurgitation (AR), using cardiac magnetic resonance (CMR) feature tracking and 4D flow imaging. Fifty BAV individuals were retrospectively selected: 15 with mild AR and posterior regurgitation jet (Group-PJ), 15 with regurgitant jet in other directions (Group-nPJ) and 20 with no regurgitation (Controls). CMR protocol included cine steady state free precession (SSFP) sequences and 4D Flow imaging covering the entire left ventricle (LV) cavity and the aortic root. Cine-SSFP images were analyzed to assess LV volumes, longitudinal and circumferential myocardial strain. Circumferential and longitudinal peak diastolic strain rate (PDSR) and peak diastolic velocity (PDV) were reduced in group PJ if compared to group nPJ and control group (PDSR = 1.10 ± 0.2 1/s vs. 1.34 ± 0.5 1/s vs. 1.53 ± 0.3 1/s, p:0.001 and 0.68 ± 0.2 1/s vs. 1.17 ± 0.2 1/s vs. 1.05 ± 0.4 1/s ; p < 0.001, PDV = − 101.6 ± 28.1 deg/s vs. − 201.4 ± 85.9 deg/s vs. − 221.6 ± 67.1 deg/s; p < 0.001 and − 28.1 ± 8 mm/s vs. − 38.9 ± 11.1 mm/s vs. − 43.6 ± 14.3 mm/s, p < 0.001, respectively), whereas no differences have been found in systolic strain values. 4D Flow images (available only in 9 patients) showed deformation of diastolic transmitral streamlines direction in group PJ compared to other groups. In BAV patients with mild AR, the posterior direction of the regurgitant jet may hamper the complete mitral valve opening, disturbing transmitral flow and slowing the LV diastolic filling.

The role of the left atrial function in the surgical management of aortic and mitral valve disease

The right management of both mitral and aortic disease can be challenging, especially in asymptomatic patients. The current guidelines recommend valve repair or replacement when symptoms arise or when there is an evident left ventricular dysfunction. However, deciding the optimal surgical timing can be very difficult, since the line between the absence of symptoms and being minimally symptomatic, especially in the elderly, is blurred. Another relevant issue regards the second surgical criterion: operating on a patient with a reduced left ventricular ejection fraction or with a dilated left ventricle might jeopardize the possibility of a fully reverse remodeling of the heart after surgery. In this scenario, the left atrium might play an important role. In particular, left atrial deformation might be a very useful tool to detect early ultrastructural alterations, and help or support guiding a patient-tailored treatment at an early stage, optimizing the outcome in the long term.