Three-dimensional left atrial strain from retrospective gated computed tomography: Comparison with speckle-tracking...

Three-dimensional (3D) left atrial (LA) deformation assessment beyond the two-dimensional (2D) apical views circumvents atrial foreshortening and can be quantified from four-dimensional (4D) retrospective gated computed tomography (CT) using novel feature tracking methods. However, the consistency between CT-derived 3D and echocardiographic 2D peak left atrial longitudinal strain (PALS) has not been reported. We aimed to compare CT-derived 3D and echocardiographic 2D PALS in patients undergoing transcatheter aortic valve implantation (TAVI).

Eighty patients (81.8 ​± ​5.8 years, 30 ​% female) who underwent CT and transthoracic echocardiography (TTE) before TAVI were included. CT images were reconstructed at 5 ​% increments over the R-R interval. 4D CT-derived deformation was evaluated using novel feature tracking, from which 2D and 3D PALS_CT were measured and compared with 2D PALS_TTE.

2D PALS_TTE and 2D PALS_CT measurements were strongly correlated (Pearson coefficient ​= ​0.84) and comparable (mean bias ​= ​-0.8; 95 ​% confidence interval, CI: -1.9 to 0.3), whereas 2D PALS_TTE exhibited systematic overestimation compared with 3D PALS_CT (mean bias ​= ​-3.6; 95 ​% CI: -4.7 to -2.5; P ​< ​0.001). 3D PALS_CT and 2D PALS_TTE exhibited comparable correlations with exercise capacity and quality of life scores and prediction of elevated brain natriuretic peptide (area under the curve, AUC: 0.84, 0.79, respectively) and diastolic filling pressures (AUC: 0.65, 0.69, respectively).

2D PALS_CT and 2D PALS_TTE showed good agreement, whereas 2D PALS_TTE was systemically larger than 3D PALS_CT which may be attributed to atrial foreshortening. 3D PALS_CT circumvents limitations of 2D echocardiography and may offer adjunctive evaluation of atrial reservoir function in patients with valvular heart disease.