Baseline LASi can unmask the asymptomatic PMR patient

Background

Severe primary mitral regurgitation (PMR) poses a clinical challenge regarding

the optimal timing of intervention. Left Atrial Stiffness Index (LASi) is a novel echocardiographic marker of the left atrium mechanics that may offer added value in identifying patients at higher risk for disease progression.

Purpose

The present study aimed to assess the relation of LASi to primary severe MR in comparison with the conventional surgical indications.

Methods

63 asymptomatic patients with moderate-to-severe or severe PMR who did not meet guideline-based intervention criteria at baseline were enrolled. All patients underwent transthoracic and bicycle stress echocardiography, including speckle-tracking analysis for left atrial strain parameters. The primary endpoint was a positive stress echo, defined as the appearance of a change in > 1 grade of MR and/or an increase in PASP >= 60 mmHg and/or the appearance of symptoms. LASi was calculated by dividing the E/e’ ratio by the Left Atrial Reservoir Strain (LASr). Receiver operating characteristic (ROC) analysis was used to determine optimal cutoff values, and multivariate logistic regression was applied to identify independent predictors of adverse outcomes.

Results

Among the 63 patients participating, 56 managed to complete the test, while 7 of them exhibited a worsening in MR grade and/or experienced symptoms of dyspnea and ended the test prematurely. An elevated LASi score with a cut-off value of 0.33 demonstrated statistically significant predictive value ( odds ratio 9.33 ; 95% confidence interval, 1.72 - 50.8 ; P < .005), and was able to identify patients with indication for mitral surgery with a good accuracy ( AUC 0.723; 95% confidence interval 0.537 - 0.909 ). No conventional parameter reached significance as a categorical variable using guideline-based cutoff values. Among conventional parameters, LA diameter, LAVi and PASP emerged as statistically significant predictors of the primary endpoint as continuous variables. In multivariate logistic regression, LASi yielded complementary predictive value when combined with the classic parameters.

Conclusions

In asymptomatic PMR patients not yet meeting intervention criteria, LASi provides prognostic information before conventional echocardiographic parameters. The combination of LASi with the current guidelines-based indicators may improve risk stratification in this patient population and potentially refine the timing of intervention.LASi and positive stress echo - chartLASi and positive stress echo - ROC curve