To evaluate the value of mitral valve spatial parameters combined with left atrial strain parameters assessed by resting echocardiography in predicting left ventricular outflow tract obstruction (LVOTO) in patients with hypertrophic cardiomyopathy (HCM).

Ninety-five patients diagnosed with HCM by echocardiography during outpatient or inpatient visits at the Sichuan Provincial People's Hospital from January 2021 to December 2023 were retrospectively included. Clinical data, conventional echocardiographic parameters, mitral valve spatial parameters, and left atrial strain parameters were obtained. According to left ventricular outflow tract gradient (LVOTG) at rest and after provocation, the subjects were divided into either a non-obstructive HCM group (n=49) or an obstructive HCM group (n=46), and the differences of the above parameters were compared between the two groups. Receiver operating characteristics (ROC) curve analysis was performed on mitral valve parameters and left atrial parameters with statistically significant differences between the two groups in the univariate analysis, and the area under the ROC curve (AUC) was calculated to obtain the optimal cutoff value and sensitivity and specificity. Parameters with statistically significant differences in the ROC curve analysis were subjected to multivariate Logistic regression analysis to identify the independent predictors and evaluate their predictive efficacy for HCM with LVOTO.

Compared with the non-obstructive HCM group, diastolic anterior mitral leaflet (AML), early-systolic and late-systolic residual mitral leaflet (RML), and left atrial stiffness index (LASI) at rest increased in the obstructive HCM group, while early-systolic and late-systolic coaptation point-interventricular septum (CS), early-systolic and late-systolic mitral leaflet tip-interventricular septum (TIS), left atrial strain during reservoir phase (LASr), and the absolute value of left atrial strain during conduit phase(LAScd) decreased. Early-systolic TIS < 21.84 mm and LASI > 0.56 were independent predictors of HCM with LVOTO, with odds ratio values of 25.248 and 13.524, respectively (both P < 0.05). The AUC values of early-systolic TIS, LASI, and their combination were 0.821, 0.715, and 0.827, respectively (all P < 0.001); their sensitivities for predicting HCM with LVOTO were 95.6%, 60.5%, and 97.8%, respectively, and the corresponding specificities were 63.8%, 78.7%, and 59.2%. Early-systolic TIS≥21.84 mm combined with LASI≤0.56 could exclude the possibility of HCM with LVOTO or occult LVOTO, with negative predictive values of 91.3% and 95.5%, respectively.

Early-systolic TIS and LASI assessed by resting echocardiography can serve as independent predictors of LVOTO in HCM. The combined application of the above two parameters can realize early prediction of LVOTO in HCM, suggesting the necessity of stress echocardiography in making the diagnosis and treatment of HCM patients more reasonable.