Usefulness of 3-Tesla Cardiac Magnetic Resonance to Detect Mitral Annular Dysfunction in Patients with Mitral Valve Prolapse

Abstract Mitral annulus disjunction (MAD) is characterized by a separation between the atrial wall mitral junction and the left ventricular (LV) free wall. Little is known regarding cardiac magnetic resonance (CMR) performance to detect MAD and its prevalence in mitral valve prolapse (MVP). Based on 89 MVP patients (63 women; mean age 64 ±13) referred for CMR assessment of MR, either from Myxomatous Mitral Valve Disease (MMVP) (n=40; 45%) or fibroelastic disease (FED) (n=49; 55%), we sought to assess the frequency of MAD and its consequences on LV morphology. Patients were classified in 2 groups according to MAD presence (MAD+) or absence (MAD-). MAD (measuring 8±4mm) was diagnosed in 35% (31/89) of MVP patients, more frequently in MMVP than FED (60% vs 14%). MAD+ was associated with MMVP; bileaflet MVP and non-sustain ventricular tachycardia (NSVT) but not with the severity of MR. Diagnostic accuracy of TTE for the detection of MAD was fair (65% sensitivity, 96% specificity) with CMR as reference. MAD+ showed significantly enlarged basal and mid LV diameters and enlarged mitral-annulus diameter. Among patients with late gadolinium enhancement, presence of LV fibrosis at level of papillary muscle was more frequent in MAD+. After adjustment on age and MR severity, MMVP and enlarged end-systolic mitral annulus diameter were independently associated with MAD+. In conclusion, MAD was present in about 1/3 of MVP patients, mostly in MMVP and independent of MR severity. Enlarged mitral-annulus and basal LV diameters, NSVT and papillary muscle fibrosis were associated with MAD presence.