Mitral Annular Disjunction Assessed Using CMR Imaging: Insights From the UK Biobank Population Study.
Zugwitz D., Fung K., Aung N., Rauseo E., McCracken C., Cooper J., El Messaoudi S., Anderson RH., Piechnik SK., Neubauer S., Petersen SE., Nijveldt R.
BACKGROUND: Mitral annular disjunction is the atrial displacement of the mural mitral valve leaflet hinge point within the atrioventricular junction. Said to be associated with malignant ventricular arrhythmias and sudden death, its prevalence in the general population is not known. OBJECTIVES: The purpose of this study was to assess the frequency of occurrence and extent of mitral annular disjunction in a large population cohort. METHODS: The authors assessed the cardiac magnetic resonance (CMR) images in 2,646 Caucasian subjects enrolled in the UK Biobank imaging study, measuring the length of disjunction at 4 points around the mitral annulus, assessing for presence of prolapse or billowing of the leaflets, and for curling motion of the inferolateral left ventricular wall. RESULTS: From 2,607 included participants, the authors found disjunction in 1,990 (76%) cases, most commonly at the anterior and inferior ventricular wall. The authors found inferolateral disjunction, reported as clinically important, in 134 (5%) cases. Prolapse was more frequent in subjects with disjunction (odds ratio [OR]: 2.5; P = 0.02), with positive associations found between systolic curling and disjunction at any site (OR: 3.6; P < 0.01), and systolic curling and prolapse (OR: 71.9; P