Observational Cohort Prospective Multicenter Study on Mitral Annular Disjunction (MAD) - MAD multiceNter Study (MAD-NesS)

Mitral annular disjunction (MAD) is a structural abnormality of the mitral annulus, defined as a separation (≥1 mm) between the atrial wall-mitral valvular junction and the left ventricular free wall during end-systole. This abnormality is significantly associated with the presence of mitral valve prolapse (MVP), but it can also be observed in normal hearts. MAD-related hypermobility of the mitral apparatus and the consequent posterior systolic curling determine a mechanical stress of the infero-basal wall and papillary muscle. This phenomenon leads to myocardial hypertrophy and fibrosis, creating an arrhythmogenic substrate and a source of electrical instability. For this reason, the analysis of left ventricle by cardiac magnetic resonance plays a pivotal role in the identification of predictors of fatal arrhythmic events, such as sudden cardiac death (SCD). Taking into account that MAD could be present without MVP, some studies analyzed the association between MAD and arrhythmic events. They showed that MAD itself is a risk marker of electrical instability supporting the existence of an emerging clinical entity: the MAD arrhythmic syndrome. An in deep analysis of MAD patients and their characteristics in terms of EKG, types of arrhythmia, echocardiographic parameters and cardiac magnetic resonance (CMR) data and long-term events is lacking.

The present study is ideated and conducted to fill this gap and collect information regarding management and outcome of patients with MAD