Echocardiographic assessment of morphofunctional and hemodynamic changes of rheumatic mitral valve dysfunction in the young. Morphological changes in rheumatic valve lesions

Abstract

Background- Rheumatic fever and its sequel rheumatic heart disease remain a major health problem across the globe. This investigation aims to analyse the mitral valve morphofunctional changes, stratified by severity, and the magnitude of the mitral regurgitation and stenosis through a simplified echocardiographic scoring system in patients with rheumatic heart disease. Methods- As cross-sectional echocardiographic study was carried out in 98 consecutive patients with confirmed rheumatic heart disease. Patients undergoing outpatient clinical care over an 18-month period (mean follow-up period of 9,7±2,9 years) were selected for echocardiographic investigation. After a double-blind echocardiograms review, the inter-rater reliability was calculated (Kappa=0.875 (0.775- 0.974; CI 95%). The morphofunctional data of mitral apparatus were scored on a rating scale from one to fifteen, encompassing three categories (1-5: mild; 6-10: moderate; 10-15: severe) to quantify the degrees of severity. Pearson's Chi-squared test with Yates' continuity correction were performed for comparative analysis and the Wilcoxon test and the Cliff's Delta effect size was calculated to examine differences related to morphological features. Results- The majority of patients had rheumatic heart disease with clinical evidence and twenty patients (20,4%) had subclinical disease.The thickening of both mitral valve leaflets and the restrictive motion of the posterior leaflet were most frequently found in contrast with the low percentage of chordal and/or commissural fusion. The degree of the anterior mitral valve leaflet thickening was proportional to the magnitude of the mitral valve regurgitation (p=0.021). The higher degrees of mitral valve dysfunction were associated with more severe carditis (mitral valve regurgitation, p: 0.000; mitral valve stenosis, p: 0.031). No association was found between the severity of valvular lesions and patient age or length of the disease (p=0.320). The presence of beading was only observed in the acute phase (p=0,000); coaptation defect of the mitral valve was associated with significant left ventricle enlargement (p=0.000). The morphofunctional score of mitral apparatus, stratified by severity, was associated with the magnitude of mitral valve regurgitation (p=0,000) and of mitral valve stenosis (p=0,031) also quantified by severity. The highest scores were observed in patients with the most severe degrees of carditis (p=0,000); however, no association was found with either, the patients’ age (p=0.373) or the duration of the disease (p=0.361). Conclusions- In the analysis of severity of the mitral apparatus deformities and the resulting valve dysfunction, the morphofunctional score stratification was highly associated with the magnitude of mitral regurgitation and stenosis. In this young cohort, the higher scores were associated to severe carditis, but not to the patients’ age or the duration of the disease. Taking into account the low prevalence of severe valve dysfunctions, these results highlight the importance of early intervention and adequate prevention.