Mitral annular disjunction; how accurate are we? A cardiovascular MRI study defining risk
Nasir Hussain1,2, Geeta Bhagia1,3, Mark Doyle1
1Allegheny Health Network, Allegheny General Hospital, Center for Cardiovascular MRI, Pittsburgh, PA 15212, USA.
Aims:
Mitral Annular Disjunction (MAD) refers to embryologic fibrous separation between mitral annular ring and basal left ventricular myocardium. Since its original description, the role of MAD in arrhythmic mitral valve prolapse (MVP) has been the subject of active research. In this study we sought to assess prognostic and imaging characteristics of MVP patients with and without underlying MAD.
Methods And Results:
Patients with posterior or bi-leaflet MVP were retrospectively identified via a review of all patients referred to our cardiac magnetic resonance (CMR) imaging laboratory from January 2015 to May 2022. MVP patients were further stratified by underlying MAD status. A total of 100 MVP patients undergoing CMR imaging (52 MVP patients with posterior MAD) were retrospectively identified with female comprising 55 % of the cohort. MVP patients with MAD were more likely to have an abnormal basal inferolateral/ papillary muscles LGE (51 % vs 21 %, p < 0.01). Posterior MAD longitudinal disjunction gap in 'mm' was a predictor of ventricular tachycardia (VT) [1.29, p = 0.01)]. Using ROC curve analysis, a disjunction gap of ≥ 4 mm was predictive of VT (AUC-0.71, p < 0.01), and incorporation of LGE in ROC model further improved AUC to 0.78 confirmed via Akaike information criterion (p < 0.01).
Conclusion:
Abnormal LGE involving basal inferolateral myocardium and papillary muscles may provide etiologic substrate for arrythmia in MVP patients.
Insights
Mitral Annular Disjunction (MAD) in mitral valve prolapse (MVP) patients is linked to abnormal heart tissue patterns and an increased risk of ventricular tachycardia (VT). A gap of 4mm or more in MAD predicts VT, especially when combined with LGE imaging.
Area of Science:
- Cardiology
- Cardiac Imaging
- Electrophysiology
Background:
- Mitral Annular Disjunction (MAD) is an embryologic separation between the mitral annulus and left ventricle.
- Its association with arrhythmic mitral valve prolapse (MVP) requires further investigation.
- Understanding MAD's role in MVP arrhythmias is crucial for risk stratification.
Purpose of the Study:
- To evaluate the prognostic and imaging characteristics of MVP patients with and without MAD.
- To identify imaging markers that predict arrhythmias in MVP patients with MAD.
- To assess the predictive value of MAD and LGE for ventricular tachycardia (VT) in MVP.
Main Methods:
- Retrospective review of 100 MVP patients undergoing cardiac magnetic resonance (CMR) imaging (2015-2022).
- Stratification of patients based on the presence and type of MAD (posterior or bi-leaflet).
- Analysis of late gadolinium enhancement (LGE) patterns and correlation with VT occurrence.
Main Results:
- MVP patients with MAD showed higher rates of abnormal basal inferolateral/papillary muscle LGE (51% vs 21%).
- Posterior MAD longitudinal disjunction gap predicted VT (p=0.01).
- A disjunction gap ≥ 4mm predicted VT (AUC=0.71), improved to AUC=0.78 with LGE inclusion.
Conclusions:
- Abnormal LGE in the basal inferolateral myocardium and papillary muscles may underlie arrhythmias in MVP patients.
- MAD, particularly with a significant disjunction gap and LGE, is associated with increased VT risk.
- CMR imaging can identify MVP patients at higher risk for ventricular arrhythmias.
