Reclassification of patients with stage 2 or higher severe aortic valve stenosis based on left atrial reservoir strain
Authors: Moya A , De Oliveira E , Dierckx R , Goethals M , Dauw J , Bartunek J , Heggermont W , Vanderheyden M 
Published: January 2025

Abstract

Introduction
Survival following Transcatheter Aortic Valve Replacement (TAVR) is significantly influenced by the extent of extra-valvular cardiac damage at the time of the procedure. Génereux et al. introduced a staging system that classifies patients as stage 2 or higher if they have left atrial (LA) damage, defined as a Left Atrial Volume Index (LAVI) greater than 34mL/m². However, Left Atrial Strain (LAS) may serve as a more advanced method for assessing, LA damage and identifying high-risk patients.

Aim
This retrospective study aimed to evaluate the contribution of LAS in addition to LAVI in assessing the impairment of LA function in severe aortic valve stenosis (AS).

Methods
All patients with LAVI &gt;34mL/m² who underwent TAVR between February 2021 and October 2023 were included in the study. Patients with poor quality echocardiographic images, moderate/severe mitral valve stenosis, mitral valve prosthesis, amyloidosis, or atrial fibrillation were excluded. Baseline echocardiographic images were analyzed offline to measure biplane LA volume, LAVI, LAS conduit (cd), LAS contractile (ct), and LAS reservoir (r). Additionally, left ventricular (LV) function was assessed by calculating ejection fraction (EF), global longitudinal strain (GLS), and myocardial work (MW) parameters. A ROC-curve analysis was performed to determine the LA parameter with the best predictive value, for stratification and survival analysis of patients.

Results
In total, 73 out of 176 AS patients were included in the analysis (39males, 83±5years, AVA 0.7±0.3cm2, MPG 47±15mmHg, LAVI 53±17mL/m²) . The majority of patients were in stage 2 while two were in stage 3 and three were in stage 4. During an average follow-up period of 419±287 days after TAVR, 11 patients died. No correlation was found between LA volume or LAVI and LV function parameters. However LAS parameters showed a significant correlation with EF and MW. Specifically, LASr had a significant correlation with EF (r=0.32), MW index(r=0.41), constructive work (CW, r=0.44), and MW efficiency (r=0.37). In the ROC-curve analysis, LASr demonstrated the highest predictive value (AUC 0.66).
Patients with LASr values below the median (18.5%) exhibited significantly poorer long-term survival rates compared to those with LASr values above the median. Patient risk re-stratification based on the median LASr showed improved specificity compared to using LAVI&gt; 34ml/m² as a risk marker (Figure 1). Furthermore, patients with low LASr values also displayed significantly worse values of GLS (-17±8 vs -14±4%, p=0.03), MW index (2598±686 vs 2054±677mmHg%, p=0.02), CW (3135±766 vs 2512±787mmHg%, p=0.02), and MW efficiency (93±5 vs 89±7%, p=0.03).

Conclusion
The identification of AS patients with LA damage (stage 2) due to LV dysfunction could be enhanced by implementing LASr as a more accurate parameter than LAVI. Additionally, LASr may help in identifying AS patients at risk following TAVR.
Figure 1: Survival Analysis