Left atrial strain as a surrogate parameter for successful percutaneous ballon mitral valvotomy?

Background: Severe mitral stenosis (MS) leads to morphological and functional changes in the left atrium (LA) causing dysfunction. Relieving mitral obstruction improves the LA mechanics and structural remodelling. However, this is not taken as a measure of successful Ballon Mitral Valvotomy (BMV) in clinical practice.

Methods: We studied the relationship between LA strain and severe MS and the short-term effect of BMV on LA mechanics in a prospective observational single-centre study.

Results: Peak atrial longitudinal strain (PALS) was impaired in patients (n = 40) with severe MS and improved 24 h following BMV (11.93 ± 3.29% vs 14.96 ± 3.59%, p < 0.001). There was a significant decrease in transmitral gradient (12.0 ± 4 mmHg vs 3.2 ± 1.6 mmHg, p < 0.001) and systolic pulmonary artery pressure (sPAP) (42.0 ± 8 mmHg vs 40.0 ± 4.8 mmHg, p < 0.001) after the procedure. Mitral valve area (1.03 ± 0.27 cm² vs 1.81 ± 0.31 cm², p < 0.001) significantly increased after the procedure. Peak atrial longitudinal strain failed to predict the success of the procedure as (AUC: 0.53; 95% CI, 0.32-0.75, p = 0.791). A cut-off value of 11.42% demonstrated a sensitivity of 64.7% and specificity of 66.7%. (R = 0.33; 95% CI 0.09, 0.6, p = 0.038).

Conclusion: Peak atrial longitudinal strain shows a significant improvement following a successful BMV. This increase in values reflects an improvement in clinical status and function class in follow-up. While PALS offers promise, it has limitations. Therefore, it seems reasonable to consider PALS as a supportive indicator alongside established markers like MV area and pressure gradient for assessing procedural success.