Left ventricular ejection fraction and Global Longitudinal Strain variability between methodology and experience

Area of Science:

• Cardiology
• Echocardiography
• Cardiac Imaging

Background:

• Ejection fraction (EF) is standard for assessing left ventricular (LV) systolic function but faces measurement challenges.
• These challenges include image quality, LV geometry assumptions, and varying expertise levels among physicians.
• Global Longitudinal Strain (GLS) is an emerging metric for LV function assessment.

Purpose of the Study:

• To evaluate the inter-observer variability of EF and GLS measurements.
• To compare the reliability of EF and GLS in patients with diverse LV function.
• To assess the impact of physician expertise on measurement variability.

Main Methods:

• 122 patients underwent EF and GLS measurements by four blinded investigators with differing experience levels.
• EF was assessed using visual estimation, biplane Simpson's method, and an auto-EF technique.
• GLS was measured from three apical views, with significant differences defined as >10 absolute values for EF and >2 for GLS.

Main Results:

• Intra-observer agreement was excellent for visual EF and GLS, and good for Simpson's and auto-EF methods.
• Intra- and inter-observer agreement for GLS was excellent (ICCs > 0.8), with no significant discordance.
• Measurement discordance for EF and GLS was not linked to image quality or wall motion abnormalities.

Conclusions:

• Global Longitudinal Strain (GLS) is more reliable for serial LV function assessment than EF.
• GLS demonstrates lower intra- and inter-observer variability, even across different levels of physician expertise.
• GLS offers a more consistent measure of LV systolic function compared to EF.