Cardiac remodeling, left atrial dysfunction and features of mitral annulus disjunction in mitral valve prolapse with mild regurgitation: morpho-functional insights from cardiac MRI

Abstract Background Mitral valve prolapse (MVP) affects 2–4% of the general population and is traditionally considered an isolated valvular disease. However, emerging evidence suggests that MVP might be associated with cardiac remodeling and mitral annulus disjunction (MAD), even in the absence of significant mitral regurgitation (MR). This study combines two analyses aimed at characterizing early cardiac remodeling and MAD geometry in MVP patients with negligible MR, using cardiac magnetic resonance (CMR). Methods 87 MVP patients with mild MR and 83 healthy controls matched for age, sex and body surface area, underwent 1.5 T CMR. Cine SSFP sequences were used to assess biventricular volumes, mass and ejection fractions (EF); feature-tracking (CMR-FT) analysis of the left atrium (LA) provided LA strain, volumes and EF. Additional parameters analysed included LV and LA sphericity indices, trabeculated myocardial mass and the non-compacted to compacted (NC/C) mass ratio. MAD was defined as a separation ≥ 1.0 mm between the junction of the left atrial wall–mitral leaflet and the basal LV wall during end-systole. MAD was assessed in 2ch, 3ch and 4ch views, and characterized by its maximal extent (MAD max), morphological pattern ("true" vs. "pseudo" MAD), and its association with tricuspid annular disjunction (TAD). MVP patients also underwent late gadolinium enhancement (LGE) and phase-contrast imaging for MR quantification. Results I) compared to healthy controls, MVP patients exhibited significant LV and LA remodeling despite negligible MR, including increased LV and LA volumes, higher sphericity indices of left-sided chambers and increased LV trabeculations. LA strain (reservoir, conduit, booster pump) and LA EF were also significantly reduced (Table and Figure). II) When searched in multiple views with high spatial and contrast resolution imaging such as CMR, MAD was a common finding in both MVP (100%) and healthy controls (74%). MVP patients showed an overall higher prevalence of MAD, with greater linear and circumferential extent, and a prevalent "pseudo" MAD configuration in 3ch and 4ch views; in healthy controls small "true" MAD were frequently observed in the 2ch view (Figure). Conclusions Patients with MVP and non-significant MR exhibit early signs of cardiac remodeling and structural-functional abnormalities, including sphericization and dilation of left-sided chambers, increased LV trabeculations, and LA dysfunction. A small anatomical MAD detectable in the 2-ch view may represent a paraphysiological variant. In contrast, more extensive MADs—especially those of functional origin arising from mitral leaflet redundancy and more clearly visualized in 3- and 4-chamber views—are closely associated with MVP and warrant further investigation to improve risk stratification.Cardiac remodeling: MVP vs. controls Cardiac remodeling and MAD features