Four-dimensional automated left atrial quantification for assessing left atrial volume and strain in patients with angiographically confirmed coronary artery disease and preserved resting left ventricular wall motion: an exploratory cross-sectional study

Left atrial (LA) mechanical abnormalities have been reported in coronary artery disease (CAD) even when overt left ventricular (LV) dysfunction is not evident. Four-dimensional automated LA quantification (4D Auto LAQ) enables comprehensive assessment of LA phasic volumes and strain. This exploratory study aimed to characterize LA volume and strain alterations using 4D Auto LAQ in CAD patients with angiographically confirmed stenosis and preserved resting LV wall motion. This single-center cross-sectional study enrolled 41 patients with angiographically confirmed CAD and preserved resting LV wall motion and 20 healthy controls. LA volume indices, LA ejection fraction (LAEF), and longitudinal and circumferential strain parameters were measured using 4D Auto LAQ. Between-group comparisons, exploratory anatomical stenosis-stratified analyses, exploratory ROC analyses, parsimonious multivariable linear regression, and an incremental discrimination analysis comparing conventional LA measurements (left atrial diameter [LAD] and LAVImax) with the same model plus LASr were performed. Intra- and inter-observer reproducibility was assessed using intraclass correlation coefficients (ICC). Compared with controls, the CAD group had higher LAVImax (33.33 ± 9.15 vs. 28.12 ± 8.15 mL/m², P = 0.035), LAVImin (14.32 ± 4.82 vs. 11.15 ± 4.18 mL/m², P = 0.015), and LAVIpreA (24.20 ± 6.91 vs. 18.59 ± 5.88 mL/m², P = 0.003), and lower LASr (22.93 ± 7.05 vs. 26.50 ± 4.93%, P = 0.046). LAVImin, LAVIpreA, and LASr differed across exploratory anatomical stenosis strata, although a consistent monotonic gradient was not demonstrated. LASr showed modest discrimination for CAD (AUC 0.696, 95% CI 0.564–0.827). Adding LASr to LAD + LAVImax increased the AUC from 0.676 to 0.738, but the paired AUC difference was not statistically significant ( P = 0.139). After adjustment for age, sex, BMI, e′, and LVEF, LAVImax and LAVIpreA remained significantly associated with CAD status, whereas LASr did not. Selected 4D Auto LAQ measures showed good to excellent reproducibility. In this selected exploratory cohort of angiographically confirmed CAD patients without major comorbidities known to affect LA mechanics, CAD with preserved resting LV wall motion was associated with larger LA volume indices and modestly lower reservoir strain. LAVImax and LAVIpreA retained adjusted associations with CAD status, whereas LASr did not. LASr provided modest discrimination, and a statistically significant incremental discriminatory value beyond LAD and LAVImax was not demonstrated. These findings support cautious interpretation of LA strain as a complementary research marker rather than a standalone CAD-specific diagnostic measure. Not applicable.