Normal echocardiographic mitral and aortic valve thickness in children

Material modeling and recent findings in transcatheter aortic valve implantation simulations

BACKGROUND AND OBJECTIVE

Transcatheter aortic valve implantation (TAVI) has significantly transformed the management of aortic valve (AV) diseases, presenting a minimally invasive option compared to traditional surgical valve replacement. Computational simulations of TAVI become more popular and offer a detailed investigation by employing patient-specific models. On the other hand, employing accurate material modeling procedures and applying basic modeling steps are crucial to determining reliable numerical results. Therefore, this review aims to outline the basic modeling approaches for TAVI, focusing on material modeling and geometry extraction, as well as summarizing the important findings from recent computational studies to guide future research in the field.

METHODS

This paper explains the basic steps and important points in setting up and running TAVI simulations. The material properties of the leaflets, valves, stents, and tissues utilized in TAVI simulations are provided, along with a comprehensive explanation of the geometric extraction methods employed. The differences between the finite element analysis, computational fluid dynamics, and fluid-structure interaction approaches are pointed out and the important aspects of TAVI modeling are described by elucidating the recent computational studies.

RESULTS

The results of the recent findings on TAVI simulations are summarized to demonstrate its powerful potential. It is observed that the material properties of aortic tissues and components of implanted valves should be modeled realistically to determine accurate results. For patient-specific AV geometries, incorporating calcific deposits on the leaflets is essential for ensuring the accuracy of computational findings. The results of numerical TAVI simulations indicate the significance of the selection of optimal valves and precise deployment within the appropriate anatomical position. These factors collectively contribute to the effective functionality of the implanted valve.

CONCLUSIONS

Recent studies in the literature have revealed the critical importance of patient-specific modeling, the selection of accurate material models, and bio-prosthetic valve diameters. Additionally, these studies emphasize the necessity of precise positioning of bio-prosthetic valves to achieve optimal performance in TAVI, characterized by an increased effective orifice area and minimal paravalvular leakage.

High burden of rheumatic heart disease confirmed by echocardiography among Pacific adults living in New Zealand

BACKGROUND

Despite numerous echocardiographic screening studies of children in high incidence acute rheumatic fever (ARF)/rheumatic heart disease (RHD) communities, little is known about the prevalence of RHD in adults in these populations.We sought to determine the prevalence of RHD in an urban area of South Auckland, New Zealand, where previous studies had shown the prevalence of RHD in children to be around 2%.

METHODS

A cross-sectional screening study was conducted between 2014 and 2016. Echocardiography clinics were conducted at an urban Pacific-led primary healthcare clinic in New Zealand. Eligible persons aged 16-40 years were recruited according to a stratified randomised approach. Echocardiograms were performed with a standardised image acquisition protocol and reported by cardiologists.

RESULTS

There were 465 individuals who underwent echocardiograms. The overall prevalence of RHD (define and borderline) was 56 per 1000 (95% CI 36 to 78 per 1000). Definite RHD was found in 10 individuals (4 of whom were already under cardiology review at a hospital clinic) with a prevalence of 22 per 1000 (95% CI 9 to 36 per 1000). Non-rheumatic cardiac abnormalities were found in 29 individuals.

CONCLUSIONS

There is a high burden of both rheumatic and non-rheumatic cardiac abnormalities in this population. Rates described in New Zealand are as high as lower-middle-income countries in Africa. Addressing knowledge gaps regarding the natural history of RHD detected by echocardiography in adults is a priority issue for the international RHD community.

Recommendations for the Use of Echocardiography in the Evaluation of Rheumatic Heart Disease: A Report from the American Society of Echocardiography

Acute rheumatic fever and its chronic sequela, rheumatic heart disease (RHD), pose major health problems globally, and remain the most common cardiovascular disease in children and young people worldwide. Echocardiography is the most important diagnostic tool in recognizing this preventable and treatable disease and plays an invaluable role in detecting the presence of subclinical disease needing prompt therapy or follow-up assessment. This document provides recommendations for the comprehensive use of echocardiography in the diagnosis and therapeutic intervention of RHD. Echocardiographic diagnosis of RHD is made when typical findings of valvular and subvalvular abnormalities are seen, including commissural fusion, leaflet thickening, and restricted leaflet mobility, with varying degrees of calcification. The mitral valve is predominantly affected, most often leading to mitral stenosis. Mixed valve disease and associated cardiopulmonary pathology are common. The severity of valvular lesions and hemodynamic effects on the cardiac chambers and pulmonary artery pressures should be rigorously examined. It is essential to take advantage of all available modalities of echocardiography to obtain accurate anatomic and hemodynamic details of the affected valve lesion(s) for diagnostic and strategic pre-treatment planning. Intraprocedural echocardiographic guidance is critical during catheter-based or surgical treatment of RHD, as is echocardiographic surveillance for post-intervention complications or disease progression. The role of echocardiography is indispensable in the entire spectrum of RHD management.

Features and behavior of valvular abnormalities in adolescent and adult patients in mucopolysaccharidosis: an echocardiographic study

Mucopolysaccharidoses, a rare inherited disorder of lysosomal storage, account for less than 0.1% of all genetic diseases.  The penetrance is highly variable and clinically it varies from severe fetal-neonatal forms to attenuated diseases diagnosed in adult individuals. The majority of the patients have been reported to show cardiac abnormalities since pediatric age, however, there is a minority of patients with attenuated disease diagnosed in the adolescent and adult age. The haematopoietic stem cell transplantation and enzyme replacement therapy are the current therapies for these disorders. Thanks to these treatments, Mucopolysaccharidoses patients live longer than in the past. Even though enzyme replacement therapy has been demonstrated to reduce left ventricular mass in patients with cardiomyopathy, the efficacy on valve abnormalities has not been clearly demonstrate yet. Furthermore, thanks to the current therapy, to better understanding and to the advent on new technologies, an increasing number of adolescent and adult patients diagnosed with MPS are followed up in the adult echocardiographic laboratory. Indeed, a systematic descriptive study describing the echocardiographic features of valvular involvement and their evolution in adolescent and adult patients lacks of medical literature and this was the aim of our investigation. Our results showed that all the valves are affected, mainly the mitral valve with a higher prevalence compared to the pediatric age.  The echocardiographic features of MPS differs from other valvular disease of adolescent and adult age, and knowing them can avoid misdiagnosis. Our observations also suggest that the progression of cardiac involvement slows after the initiation of the therapy in our group of age. Further studies on larger population are required to confirm our results.

Echocardiography for latent rheumatic heart disease in first degree relatives of children with acute rheumatic fever: Implications for active case finding in family members

BACKGROUND

Individuals with Acute Rheumatic Fever (ARF) often report a family history of ARF or Rheumatic Heart Disease (RHD) however the degree of familial susceptibility to RHD is poorly defined. This study aimed to determine RHD prevalence among first degree relatives of ARF patients using echocardiography.

METHODS

Children with ARF were recruited from Auckland, New Zealand. Parents and siblings ≥ 4years were offered echocardiography. Echocardiograms were reported according to World Heart Federation 2012 criteria. RHD prevalence in first degree relatives was compared to previously established population rates in the region.

FINDINGS

In total, 70 index cases with ARF were recruited. Echocardiography was performed in 94 parents and 132 siblings. There were 3 siblings with definite RHD and 9 with borderline RHD. There were 4 parents with definite RHD. Overall prevalence of RHD (definite and borderline) in siblings was 90/1,000 (95% CI 45-143/1,000) compared to 36/1,000 (95% CI 30-42/1,000) in New Zealand children from high ARF incidence populations (p 0.001). Prevalence of definite RHD in parents was 42/1,000 (95% CI 7-87/1,000) compared to 22/1,000 (95% CI 9-36/1,000) in adults from a high ARF incidence New Zealand population (p 0.249).

INTERPRETATION

RHD prevalence in siblings and parents of ARF cases is significantly greater than in comparable background populations. The contribution of hereditary versus environmental risk factors remains uncertain. We recommend targeted echocardiographic case-finding among siblings and parents of ARF/RHD cases in order to detect previously unrecognized latent RHD.

Screening for rheumatic heart disease: The reliability of anterior mitral valve leaflet thickness measurement

BACKGROUND

Studies determining the reliability of the World Heart Federation (WHF) anterior mitral valve leaflet (AMVL) measurement are limited by the introduction of bias in their test-retest analyses. This study sought to determine the reliability of the current AMVL measurement while controlling for systematic bias.

METHODS

Retrospective analysis of echocardiographic data from 16 patients with previous acute rheumatic fever was performed. Included in this study was an optimized cine loop of the mitral valve (MV) [reader-optimized measurement (ROM]) in the parasternal long-axis view and an optimized still image of the MV obtained from the same cine loop [specialist-optimized image (SOI)]. Each still image and associated cine loop was quadruplicated and randomized to determine intra- and inter-rater agreement and quantify the impact of zoom on AMVL measurement.

RESULTS

Specialist-optimized image without zoom reflected the highest degree of agreement in both cohorts with an ICC of 0.29 and 0.46. The agreement in ROM images without zoom was ICC of 0.23 and 0.45. The addition of zoom to SOI decreased agreement further to an ICC of 0.20 and 0.36. The setting associated with the poorest agreement profile was ROI with zoom with an ICC of 0.13 and 0.34, respectively. The intra-rater agreement between readers in both cohorts was moderate across all settings with an ICC ranging between 0.64 and 0.86.

CONCLUSIONS

The WHF AMVL measurement is only moderately repeatable within readers and demonstrates poor reproducibility that was not improved by the addition of a zoom-optimized protocol. Given our study findings, we cannot advocate the current WHF AMVL measurement as a reliable assessment for RHD.

Inter-rater and intra-rater reliability and agreement of echocardiographic diagnosis of rheumatic heart disease using the World Heart Federation evidence-based criteria

OBJECTIVE

Different definitions have been used for screening for rheumatic heart disease (RHD). This led to the development of the 2012 evidence-based World Heart Federation (WHF) echocardiographic criteria. The objective of this study is to determine the intra-rater and inter-rater reliability and agreement in differentiating no RHD from mild RHD using the WHF echocardiographic criteria.

METHODS

A standard set of 200 echocardiograms was collated from prior population-based surveys and uploaded for blinded web-based reporting. Fifteen international cardiologists reported on and categorised each echocardiogram as no RHD, borderline or definite RHD. Intra-rater and inter-rater reliability was calculated using Cohen's and Fleiss' free-marginal multirater kappa (κ) statistics, respectively. Agreement assessment was expressed as percentages. Subanalyses assessed reproducibility and agreement parameters in detecting individual components of WHF criteria.

RESULTS

Sample size from a statistical standpoint was 3000, based on repeated reporting of the 200 studies. The inter-rater and intra-rater reliability of diagnosing definite RHD was substantial with a kappa of 0.65 and 0.69, respectively. The diagnosis of pathological mitral and aortic regurgitation was reliable and almost perfect, kappa of 0.79 and 0.86, respectively. Agreement for morphological changes of RHD was variable ranging from 0.54 to 0.93 κ.

CONCLUSIONS

The WHF echocardiographic criteria enable reproducible categorisation of echocardiograms as definite RHD versus no or borderline RHD and hence it would be a suitable tool for screening and monitoring disease progression. The study highlights the strengths and limitations of the WHF echo criteria and provides a platform for future revisions.