A particular phenotype of mitral valve prolapse (MVP) was identified as linked to sudden-death (SD) associating myxomatous, bi-leaflet and prolapse with mitral annular disjunction (MAD), so called ‘severe myxomatous mitral valve disease’ (SMMVP).

Description of the prevalence and the echocardiographic characteristics of SMMVP in a cohort of MVP patients.

From a single center echocardiographic database, patients with MVP were retrospectively enrolled from January 2016 to December 2017 and echocardiographic characteristics, based for all patients on reports and additional measurement, were reported. Results Among 101 patients included (female, n=50; 59±16 years), we reported 71 patients with myxomatous MVP and 30 patients with fibro-elastic deficiency (FED). All patients with MAD (n=22/101) had myxomatous bi-leaflet MVP (i.e. SMMVP). Compared to FED, SMMVP patients were younger (52±13 vs. 68±13 years, P=0.02), without flail leaflet (0 vs.7 patients, P<0.0001), with lower left ventricle (LV) ejection fraction (65±9% vs. 76±5%, P=0.002) and greater LV end-systolic diameter (31±5mm vs. 25±5mm, P=0.005) as systolic mitral annulus diameter (43±7 vs. 33±4mm, P=0.0009). SMMVP patients had, compared to FED and Barlow groups, a deeper MVP (6.5±2.1mm vs. 3.8±1.2mm, P=0.0096; vs. 4.4±1.4mm, P=0.009) with thicker distal posterior mitral leaflet (5.5±1.2mm vs. 3.4±0.8mm, P 0.004; vs. 4.3±1.6mm, P=0.01) and lower mitral regurgitation (MR) (3/22 vs. 22/30 vs. 24/49 patients with severe MR, P<0.0001). Among 101 MVP, 5 had SD history, all had a SMMVP. SMMVP patients with SD had larger MAD (10.3±1.5 vs. 6.9±1.7mm, P=0.007), deeper MVP (8.8±2. vs. 5.1±1.9mm, P=0.04) and larger systolic annulus diameter (48±2 vs. 40±6mm, P=0.02) than the other SMMVP.

Among MVP population, SMMVP is an independent MVP entity. This phenotype is all the more specific because it is linked to SD, associating severe deep myxomatous bi-leaflet prolapse with large MAD.