Mitral annular disjunction on cardiac MRI: Prevalence and association with disease severity in Loeys-Dietz syndrome

The purpose of this study was to evaluate mitral annular disjunction (MAD) on cardiac magnetic resonance imaging (MRI) in Loeys-Dietz Syndrome (LDS) and to explore its association with adverse outcomes. In this retrospective cohort study, adult patients with LDS who underwent cardiac MRI were evaluated for MAD, aortic dimensions, and ventricular volumetry. Aortic events were defined as aortic surgery and/or dissection and severe arrhythmic events as cardiac arrest or sustained ventricular tachycardia (VT). Among 46 LDS patients (52% female, 37.2 ± 14.3 years), 17 had MAD (37%). MAD and no MAD groups were similar in age, sex, aortic dimensions and left ventricular parameters. After a clinical follow-up of 4.3 years (IQR 1.5–8.4), 3 in MAD and 4 in no MAD groups required aortic valve sparing root replacement (VSRR) and 1 in MAD developed type A dissection. Over a similar imaging follow-up period [4.1 years (IQR 2.7–9.1) vs. 3.2 years (IQR 1.0–9.0), p = 0.65], compared to baseline, increase in native aortic root size was significant only in MAD (39.4 ± 4.6 mm vs. 38.1 ± 5.3 mm, p = 0.02, 19.3 ± 2.4 mm/m2 vs. 18.7 ± 2.4 mm/m2, p = 0.01) compared to those without MAD. Patients with MAD were younger at first aortic event compared to those without (26.7 ± 11.5 years vs. 45.0 ± 14.9 years, p = 0.03). MAD distance correlated with need for VSRR, r = 0.57, p = 0.02. Two patients in the MAD group developed sustained VT. No cardiac arrest or death was observed. MAD is highly prevalent in LDS, associated with progressive aortic dilatation, and aortic events at younger age. MAD may be a marker of disease severity necessitating close surveillance. •Mitral annular disjunction (MAD) is highly prevalent in Loeys-Dietz Syndrome (LDS).•Patients with LDS and MDS have aortic events (intervention and/or dissection) at a younger age and more progressive aortic dilatation compared to those without MAD.•MAD is easily identified on cardiac MRI routinely performed for monitoring aortic dimensions in patients with LDS.•MAD in LDS should be highlighted, as it may be a marker of disease severity, necessitating close monitoring and surveillance of clinical outcomes.