Masci, P G

Abstract Background Mitral valve prolapse (MVP) is the most common valvular abnormality in the population. Emerging evidence suggests that MVP is associated with left ventricular (LV) remodelling and dysfunction regardless of mitral regurgitation (MR) severity mimicking an early stage of dilated cardiomyopathy. However, prior studies have provided scattered results and were limited by small sample size and poor adjustment for confounders. Purpose To assess early cardiac chamber remodelling associated with MVP in absence of significant MR. Methods This multicentre, retrospective case-control study included patients with isolated MVP without significant MR undergoing CMR including late gadolinium enhancement (LGE). Healthy controls (HC) were selected from local databases and included subjects without cardiovascular pathology or significant comorbidities, with normal CMR parameters defined as comprised within normality ranges reported in the literature. Propensity-score-matching (PSM) was performed in a 1:1 nearest neighbour without replacement method (calliper 0.1), based on age, sex, body-surface-area, hypertension, and diabetes. The impact of MVP on cardiac remodelling was quantified using absolute standardized mean differences (SMDs). Results A total of 587 MVP patients and 583 HC were included, with 517 pairs successfully matched after PSM. Compared to HC, MVP patients showed greater left atrial (LA) area (12.2 [10.5 – 14.1] vs. 11.0 [9.5 – 12.4] cm²/m²), left ventricular (LV) end-diastolic-volume (86.3 [72.4–101.4] vs. 76.3 [66.1–86.0] ml/m²), and lower LV ejection-fraction (60.0% [55.2–65.6] vs. 61.0% [58.0–66.0], all p<0.001). MVP patients also showed greater right atrial area, right ventricular end-diastolic-volume, and higher right ventricular ejection-fraction compared to HC (Figure 1). The greatest impact of MVP on remodelling was observed for LV-end-diastolic volume and left atrial size (SMD ~0.55–0.62, respectively), (Figure 2). Among patients with MVP, remodelling was most pronounced in patients with bi-leaflet MVP and LGE. Conclusions In the absence of significant MR, MVP is associated with cardiac chambers’ remodelling with a particular emphasis on LV and LA dilatation.Cardiac chamber parameters in HC vs. MVP Effect size of MVP on cardiac remodeling