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

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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 (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 ± 4 mm) was diagnosed in 35% (31 of 89) of MVP patients, more frequently in MMVP than fibroelastic disease (60% vs 14%). MAD+ was associated with MMVP; bileaflet MVP and nonsustain ventricular tachycardia but not with the severity of MR. Diagnostic accuracy of transthoracic echocardiography 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. In 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, nonsustain ventricular tachycardia and papillary muscle fibrosis were associated with MAD presence.

Section snippets

Methods

The study was conducted at the Monaco Heart center, Monaco. We, retrospectively evaluated 89 patients with echocardiographic diagnosis of MVP, consecutively referred for CMR assessment of MR, over a 24-months period. Exclusion criteria were more than mild aortic stenosis, aortic regurgitation or mitral stenosis, intracardiac shunt, and standard contraindications to CMR. Institutional review board approval was obtained before conducting the study. The study was conducted in accordance with

Results

Eighty-nine patients (63 women; mean age 64 ± 13) with MVP were consecutively referred for CMR assessment of MR. Baseline demographic and clinical characteristics of the 89 patients are displayed in Table 1. MAD was diagnosed in 35% (31 of 89) of MVP patients, measuring 8 ± 4 mm [2 to 16 mm]. A typical curling motion (mean length 4 ± 4 mm) was found in 64%, considered severe (≥3.5 mm) in 75%. MAD was more frequent in MMVP than in FED (60% vs 14%; p <0.0001). Ventricular arrhythmia was

Discussion

Our study using 3-Tesla CMR shows that MAD was present in about 1/3 of MVP patients, more frequently in MMVP than in FED, independently of MR severity. Enlarged MA and basal LV diameters, ventricular arrhythmias and papillary muscle fibrosis were associated with the presence of MAD. Comprehensive CMR study of MVP should include a careful description of MAD, alongside with other risk factors of ventricular arrhythmia such as focal fibrosis, irrespectively of MR severity.

Prevalence of MAD in the

Disclosures

The authors have no conflicts of interest to disclose.

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