Left atrial strain measured by the new speckle tracking dedicated software: feasibility and reproducibility in healthy and pathologic subjects
Authors: Mandoli G E , Pastore M C , Procopio M C , Pica A , Benfari G , Cavigli L , D'ascenzi F , Focardi M , Valente S , Cameli M 
Published: June 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
left atrial (LA) strain by speckle tracking echocardiography (STE) is gaining increasing evidence as diagnostic and prognostic tool in several clinical settings. However, the lack of a dedicated software was considered one of its main limitations, although many studies proved a good feasibility and reproducibility of a ventricular-based software. Brand-new fully automated software tools dedicated to the LA have been developed, both for on-line use on the echocardiographic machine and for off-line use on the workstation.

Purpose
The purpose of our study was to compare LA strain measures acquired by the new fully automated dedicated software with the "traditional" semi-automated ventricular based one in healthy, pressure-overloaded, and volume-overloaded patients.

Methods
Grey scale apical 4-chamber view echocardiographic images acquired by an experienced operator (GE, Vivid E9, Orthern, Norway) in healthy patients, patients with pressure overload (arterial hypertension, aortic stenosis) and pressure-volume overload (mitral regurgitation, heart failure) were analyzed. STE was performed offline by two independent experienced operators, using both the semi-automated and the fully automated Echopac (Milwaukee,Wisconsin) software, which was then compared using matched-pairs analysis. Both operators were blinded to the other measures and repeated the same measurement on the same images after 10 days. Measurement of LA strain was performed on-line on the echocardiographic machine in a selected group of 20 patients by one of the two operators. Patients with prosthetic valves, heart transplantation, atrial fibrillation were excluded.

Results
Overall, 100 patients were analyzed (41 healthy patients, 28 with pressure overload, 31 with pressure-volume overload). Peak atrial longitudinal strain (PALS) showed a high reproducibility with both methods. However, the dedicated method had a slightly higher inter-operator reproducibility (intraclass correlation coefficient(ICC)=0.97; 95% CI=[0.87;0.99] vs. ICC=0.96 [9.87;0.99] ) (Fig.1) and intra-operator reproducibility (ICC=0.99 [0.99;0.99] vs. 0.98 [0.98;0.99] (Fig.2); correlation=0.85, p&lt;0.001in operator 1 and 0.97 [0.95;0.98] vs. 0.95 [0.92;0.96]; correlation=0.83, p&lt;0.001 in operator 2) with a slightly lower time consumption (90 s vs. 105 s) than the traditional ventricular-based one. On-line software showed a nearly perfect reproducibility with offline software [ICC=0.99 [0.99;1]] with a further time saving (60 vs. 90 s).

Conclusions
the new fully automated software for the analysis of LA strain has a high inter-operator and intra-operator reproducibility. Both the automated and the traditionally used semi-automated software calculation provided optimal reproducibility and time-consumption, for different categories of subjects, and could be equally chosen for strain calculation in daily clinical practice. On-line LA strain calculation allows a reliable and time-saving measurement.