Vendor and software based variation in left atrial strain measurements: implications for clinical practice

Area of Science:

• Cardiology
• Medical Imaging
• Echocardiography

Background:

• Left atrial strain (LAS) is a key echocardiographic marker for left atrial function.
• Variability in LAS measurements across different software platforms hinders its widespread clinical adoption.

Purpose of the Study:

• To compare LAS measurements from a dedicated tool, AFI-LA (GE), with established left ventricular (LV)-based strain platforms (GE EchoPAC, TomTec-Arena).
• To assess the agreement, correlation, and reproducibility of LAS measurements across these different software vendors.

Main Methods:

• LAS was measured in 112 subjects (sinus rhythm and paroxysmal atrial fibrillation) using AFI-LA, GE EchoPAC (mid-myocardial and endocardial tracking), and TomTec-Arena.
• Agreement was evaluated using Bland-Altman analysis and Pearson correlation.
• Inter- and intra-observer reproducibility was assessed.

Main Results:

• AFI-LA demonstrated good correlation with GE EchoPAC and TomTec (r ≥ 0.7, p < 0.001).
• AFI-LA consistently underestimated strain values compared to GE-mid, GE-endo, and TomTec, with the smallest bias against GE-mid.
• High inter- and intra-observer reproducibility was observed for AFI-LA (r > 0.85).

Conclusions:

• AFI-LA provides LAS measurements comparable to GE mid-myocardial strain but systematically underestimates values from GE endocardial and TomTec.
• Vendor-specific calibration is necessary for AFI-LA before serial assessments or use with existing clinical thresholds.
• Further validation studies are required for standardization and broader clinical adoption of AFI-LA.