Echocardiographic assessment of the right heart pulmonary circulation unit in mitral regurgitation due to mitral valve prolapse

Abstract Background Right ventricular evaluation is essential in the context of chronic mitral regurgitation (MR). Chronic MR is associated with a progressive cardiac remodeling with enlargement and dysfunction of all cardiac chambers, and the development of functional tricuspid regurgitation (TR). Besides, right ventricle (RV) dysfunction and functional TR have been shown to influence patient prognosis. Purpose The aim of this study was to evaluate simple and combined echocardiographic parameters analysing the right heart – pulmonary circulation unit, according to the severity of MR. Methods In this monocentric retrospective study, echocardiographic studies of patients followed for a mitral valve prolapse (with or without MR) were reviewed. Usual parameters analysing RV morphology, load and function were obtained. Combined parameters of RV – pulmonary artery (RV-PA) coupling were calculated: TAPSE/PASP and RVFWS/PASP. Comparison between MR grades were performed with ANOVA or Kruskal Wallis tests as appropriate. Two-by-two post-hoc comparisons of continuous variables across the 5 groups were made using the Bonferroni correction. Results 158 patients with mitral valve prolapse (MVP) were included: 37 without MR, 28 with mild MR, 23 with mild-to-moderate MR, 21 with moderate-to-severe MR and 49 with severe MR. Clinical and echocardiographic results are presented in Table 1. Patients with a higher-grade MR tended to be older and were more likely to be men. They were also significantly more symptomatic. Most echocardiographic parameters were significantly different between grades of MR. RV remodeling, studied with morphologic parameters, started with the first grade of MR and had a linear progression between levels of MR severity (Figure 1A). Load parameters were stable until grade 2 and then showed progressive increase of RV afterload. RV free wall strain slightly increased with MR grade 1, and then decreased with each grade of MR (Figure 1B). RV fractional area change, Tissue Doppler MPI and RV free wall strain rate tended to stagnate between grade 0 and 2, and then they progressively decreased. Combined parameters of RV-PA coupling including load and function, increased with the first grade of MR, and then gradually decreased (Figure 1C). Conclusion In this study, multiparametric assessment of the cardiopulmonary unit in patients with MVP showed that RV morphologic remodeling starts with the first grades of MR, before any significant increase of pulmonary pressure. This remodeling seemed to initially enhance RV function (evaluated with parameters of RV – pulmonary artery coupling) in the first grade of MR and was then followed by a progressive decrease of RV function with the increasing severity of MR.