Early Diastolic Dysfunction Detection in Hypertension: CMR-Derived Left Atrial Strain.

Rationale And Objectives: This study aimed to investigate the role of cardiac magnetic resonance (CMR)-derived left atrial (LA) strain parameters in evaluating early cardiac dysfunction in hypertensive patients and to assess their diagnostic utility for left ventricular diastolic dysfunction (LVDD).

Methods: A total of 150 hypertensive patients and 60 healthy controls were retrospectively enrolled, with all participants undergoing both echocardiographic and CMR examinations. Hypertensive patients were stratified by LVDD severity based on current guidelines. CMR feature-tracking (CMR-FT) was utilized to quantify LA strain, including reservoir, conduit, and booster pump functions. Intergroup comparisons of functional parameters and LA strain profiles were performed, alongside correlation analysis with conventional echocardiographic diastolic markers. Receiver operating characteristic (ROC) analysis was performed to evaluate the utility of LA strain for detecting LVDD in hypertensive patients, and a multivariable diagnostic model incorporating additional parameters was established. Bootstrap resampling (1000 iterations) was used for internal validation.

Results: Compared with healthy controls, hypertensive patients exhibited impaired reservoir (εs) and conduit (εe) strains, which worsened progressively with increasing LVDD severity. εs showed significant differences across all LVDD subtypes (all p<0.05). Booster pump strain (εa) remained preserved or mildly elevated in early-stage hypertension, yet declined in advanced LVDD. LA strain and strain rate parameters demonstrated robust correlations with conventional diastolic indices. ROC analysis identified εs < 29.3% (95% confidence interval [CI]: 27.8%-31.3%) as the optimal single indicator for detecting LVDD in hypertensive patients, with a mean area under the curve (AUC) of 0.856 (95%CI: 0.706-0.968), sensitivity of 0.859 (95%CI: 0.667-1.000), specificity of 0.851 (95%CI: 0.682-0.964). The multivariable diagnostic model, which integrated conventional echocardiographic diastolic markers, εs, and LA volume, exhibited superior performance, with a mean AUC of 0.929 (95%CI: 0.824-0.994), sensitivity of 0.887 (95%CI: 0.692-1.000), and specificity of 0.927 (95%CI: 0.792-1.000).

Conclusion: CMR-derived LA strain parameters served as sensitive early markers for detecting LVDD in hypertension. They progressively deteriorate with the diastolic dysfunction severity and provide incremental value for LVDD diagnosis.