Mitral annular disjunction and high-risk profiles: a conceptual approach to risk stratification and surgical implications.

OBJECTIVE

Mitral annular disjunction (MAD), frequently associated with Barlow's disease, links degenerative mitral regurgitation to postoperative ventricular arrhythmias and sudden cardiac death, even after technically successful valve repair. However, despite advances in mitral repair, the arrhythmic substrate associated with MAD remains insufficiently addressed in current surgical paradigms.

METHODS

A systematic search of PubMed and Google Scholar (2000-2025) was conducted using keywords including "mitral annular disjunction," "mitral regurgitation," "arrhythmic mitral valve prolapse," and "mitral valve surgery." Of 264 records screened, 41 peer‑reviewed articles, prioritizing high‑impact registries and surgical cohorts, were selected for synthesis.

RESULTS

MAD is associated with paradoxical annular curling and traction‑related myocardial remodeling, which may contribute to fibrosis through pathological stretch. Observational studies suggest that higher‑risk features-such as extensive MAD (≥ 5 mm, particularly ≥ 8.5 mm), late gadolinium enhancement, or syncope-are linked to increased arrhythmic vulnerability. Although modern repair techniques can eliminate anatomical MAD, pre‑existing substrate abnormalities may persist, and ventricular arrhythmias can still occur after technically successful repair.

CONCLUSIONS

The extent of disjunction and the presence of associated substrate abnormalities appear to influence long‑term rhythm stability. A conceptual, hypothesis‑generating framework that integrates structural, electrical, imaging, and clinical information may help inform risk stratification. Prospective studies are needed to determine whether a risk‑stratified approach or optimized intervention timing can modify arrhythmic risk or potentially affect long‑term outcomes.