Clinical Report: Arrhythmogenic Risk Stratification in Mitral Valve Prolapse via CMR

Overview

Mitral valve prolapse (MVP) affects 2–3% of the population and carries a low overall risk of sudden cardiac death (SCD). However, a subset termed arrhythmic MVP (AMVP) is at higher risk for malignant ventricular arrhythmias (co-VAs). This systematic review and meta-analysis evaluates cardiac magnetic resonance (CMR) imaging features that discriminate MVP patients with co-VAs from those without, aiming to improve arrhythmic risk stratification.

Background

MVP is characterized by superior displacement of mitral valve leaflets and can lead to mitral regurgitation (MR). While most patients have a favorable prognosis, some develop complex ventricular arrhythmias and are at risk of SCD. Identifying these high-risk patients remains challenging. CMR imaging offers detailed assessment of left ventricular size/function, MR severity, leaflet morphology, mitral annular disjunction (MAD), and fibrosis via late gadolinium enhancement (LGE), which may aid in risk stratification.

Data Highlights

The meta-analysis included studies assessing CMR parameters such as LV size and function, MR severity, leaflet length/thickness, MAD, curling, LGE, and T1 mapping in MVP patients with and without co-VAs. Associations were quantified using Hedge’s g or pooled LogORs with 95% confidence intervals. Heterogeneity was evaluated by Cochran’s Q and I2 tests.

Key Findings

• Co-VAs in MVP patients include non-sustained ventricular tachycardia, sustained ventricular tachycardia, ventricular fibrillation, and aborted sudden cardiac death.
• CMR features such as mitral annular disjunction (MAD) and late gadolinium enhancement (LGE) are associated with increased arrhythmic risk.
• Other imaging markers linked to arrhythmias include longer anterior mitral leaflet length, leaflet thickness, and presence of curling.
• Left ventricular size and function and mitral regurgitation severity also contribute to arrhythmic risk stratification.
• There is significant heterogeneity among studies, highlighting the need for standardized CMR protocols and definitions.

Clinical Implications

CMR imaging should be integrated into the clinical evaluation of MVP patients to identify those at elevated risk for malignant ventricular arrhythmias. Detection of MAD, LGE, and leaflet abnormalities can guide tailored monitoring strategies such as implantable loop recorders and preventive therapies including beta-blockers or implantable cardioverter defibrillators. This approach may improve outcomes by enabling early intervention in high-risk individuals.

Conclusion

This systematic review underscores the pivotal role of CMR in arrhythmic risk stratification among MVP patients. Incorporating CMR-derived structural and tissue characterization parameters can enhance identification of patients at risk for complex ventricular arrhythmias and sudden cardiac death.

References

1. European Heart Rhythm Association (EHRA) Expert Consensus Statement 2021 -- Arrhythmic Mitral Valve Prolapse
2. 2021 ESC/EACTS Guidelines for the Management of Valvular Heart Disease
3. Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) Statement
4. Agency for Healthcare Research and Quality (AHRQ) Guidelines on Risk of Bias Assessment