Abstract 17044: Normal Ranges of Right Atrial Strain by Contemporary Echocardiography Software: A Prospective Comparative Cohort Study

Abstract

Introduction: Right atrial strain (reservoir RASr, conduit RAScd and contractile RASct) are increasingly utilized in the clinical and research setting such as for diastology grading, heart failure and valvular heart disease. However, the feasibility and reference ranges of right atrial strain measurements by contemporary strain software on different vendor scanners are not well established. We evaluated and compared two-dimensional right atrial strain values, reference ranges and associated factors across three strain software vendors in healthy subjects. Methods: Healthy subjects (n=100) undergoing echocardiography during January-April 2023 were prospectively studied, with equal number by age-groups, gender and GE versus Philips scans. Right atrial strains were quantified using TomTec version 51.02 (Autostrain LA), EchoPAC version 206 (AFI-LA) and VVI software for statistical analyses. Results: The table shows the right atrial strain means (and lower limits of normal defined as 95 th percentile) ± standard error by strain software, including RASr of 41.2±0.9% (29.6±1.6%) by TomTec, 35.9±0.7% (27.0±1.3%) by EchoPAC (which could only measure on GE scans), and 44.8±1.3% (27.6±2.2%) by VVI. EchoPAC measurements of right atrial strain were significantly less negative than TomTec or VVI (P<0.01), while TomTec has slightly less negative measurements than VVI for RASr only but similar for RAScd and RASct. Multivariable linear regression showed systolic blood pressure to be significantly associated with RASr measured by VVI with beta coefficient (95%CI) per 1 mmHg of 0.23 (0.08-0.38), why no factors were significantly associated with RASr measured by TomTec or EchoPAC. Conclusions: TomTec and VVI were vendor neutral for measuring right atrial strains, while EchoPAC can only measure this on GE scans. Normal means, lower limits of normal and associated factors of right atrial strain measurements by strain vendor were established for clinical applications.