# Prognostic implications of impaired three-dimensional left atrial function and stiffness in primary mitral regurgitation

## TL;DR

This study shows that 3D echocardiography can better predict risks in patients with mitral regurgitation compared to traditional methods.

## Contribution

The study introduces 3D left atrial strain and stiffness as novel predictors of adverse outcomes in primary mitral regurgitation.

## Key findings

- Low 3D LASr and increased LA stiffness were strong predictors of adverse events.
- 3D indices improved risk prediction beyond traditional models.
- Findings suggest 3D echocardiography could guide clinical decisions in MR patients.

## Abstract

In patients with mitral regurgitation (MR), cardiac remodeling by two-dimensional (2D) echocardiography is variable and less suitable for individualized risk assessment. We evaluated whether three-dimensional (3D) peak LA reservoir strain (LASr) and stiffness improve risk prediction in primary MR.

In the prospective 3D Echocardiography and Cardiovascular Prognosis in Mitral Regurgitation (3D-PRIME) study, 110 patients with moderate or greater primary MR underwent 2D/3D echocardiographic assessment of LASr and LA stiffness (i.e. (mitral E-wave/ annular e’ velocity)/ LASr). The primary outcome was a composite of death, heart failure worsening and mitral valve intervention.

During 24 [17–26] months follow-up, the primary outcome occurred in 59 patients. In multivariable Cox analyses, low 3D LASr (HR 2.1, 95% CI 1.1–4.3) and increased 3D LA stiffness (HR 3.5, 95% CI 1.6–7.4) predicted higher risk of adverse events after adjustment for left ventricular (LV) global longitudinal strain (GLS), MR severity, LV end-systolic volume and maximum LA volume (p < 0.05). In likelihood ratio tests, 3D LASr or LA stiffness (but not the corresponding 2D indices) increased the predictive value of a model including LV GLS and current indications for intervention in primary MR (χ2 -increase from 58 to 63 / 70, p < 0.05).

In moderate or greater primary MR, impaired LA function by 3D echocardiography is associated with higher risk of disease progression towards death, worsening heart failure and mitral valve intervention. Our findings lay the groundwork for future multicenter studies to explore the value of routine assessment of 3D LA remodeling in the follow-up of patients with primary MR.

3D LA strain and stiffness and clinical outcomes in primary MR