Abstract 16239: Left Atrial Function by Speckle-Tracking Echocardiography in Mitral Valve Prolapse: Evidence of a Primary Atriopathy and Clinical Implications

Abstract

Background: Prior studies support the prognostic role of left atrial (LA) volume in predicting overall mortality in mitral valve prolapse (MVP). However, the prognostic impact of LA function on cardiac outcome as quantified by speckle tracking echocardiography (STE) is unknown. Moreover, whether the mitral leaflet “atrialization” observed in bileaflet MVP with mitral annular disjunction (MAD) affects LA function irrespective of mitral regurgitation (MR) severity remains unclear. We sought to investigate the prognostic role of LA global longitudinal strain (LAGLS) and MVP subtype in a large registry of MVP patients with various degrees of MR. Methods: We identified 411 consecutive patients (59±17 years, 52% women) with MVP and clinical, echocardiographic and outcome data. LAGLS was measured offline using STE. Survival analysis was performed to assess the composite risk of cardiac death, heart failure hospitalization, or new onset of atrial fibrillation. Results: Compared to other MVP subtypes, bileaftlet MVP had lower LAGLS regardless of MR severity ( Fig 1A&1B ). Of note, in the subgroup with no or mild MR, LAGLS was significantly lower in bileaflet compared to posterior MVP (p=0.003). There was a trend toward lower LAGLS according to MVP with vs without MAD (p=0.08) ( Fig 1C ). In multivariable linear regression adjusted for several risk factors, including MR grade, bileaflet MVP remained significantly associated with lower LAGLS (p=0.003). A total of 79 cardiovascular events occurred during a mean follow-up of 4.6±2.9 years. There was a significant increase in the risk of events as LAGLS decreased (log-rank: p<0.001) ( Fig 1D ). Conclusion: Bileaflet MVP is associated with lower LAGLS regardless of MR severity, suggesting a primary atriopathy in this MVP subtype. Abnormal LAGLS is linked to higher risk of cardiovascular events. Hence, assessment of LA function using STE may help improve risk stratification in MVP and could represent a useful tool in clinical practice.