Body‐Size Indexation of Left Atrial Volume in Heart Failure with Preserved Ejection Fraction: Retrospective Reclassification and E/e′ Concordance
Xiaolin Wu, Heqiang ZhangABSTRACT
Purpose
To determine whether associations between body mass index (BMI) and left atrial (LA) size differ when LA volume is expressed as absolute volume, indexed to body surface area (BSA), or indexed to height squared, and whether discordant classification is associated with E/e′ in heart failure with preserved ejection fraction (HFpEF).
Methods
This retrospective observational study linked MIMIC‐IV and MIMIC‐IV‐ECHO. The complete‐indexation cohort comprised 1663 adults with a documented heart failure diagnosis, left ventricular ejection fraction ≥50%, and required body‐size and LA measurements. Multivariable models evaluated BMI associations with absolute LA volume, LAV/BSA, and LAV/height 2 . Discordance was defined as BSA‐normal but height 2 ‐enlarged; adjusted E/e′ was compared with the group normal by both methods.
Results
BMI was positively associated with absolute LA volume ( β = 0.345; 95% CI, 0.124–0.567), inversely associated with LAV/BSA ( β = −0.329; 95% CI, −0.456 to −0.203), and positively associated with LAV/height 2 ( β = 0.156; 95% CI, 0.077–0.236). Discordant classification occurred in 389 of 1663 participants (23.4%). Adjusted E/e′ was 1.630 higher (95% CI, 0.738–2.522) than in participants normal by both methods. The absolute reclassification proportion decreased to 9.6% with an alternative published height 2 threshold.
Conclusion
Body‐size normalization materially changed apparent LA enlargement in this selected HFpEF population. BSA‐normal/height 2 ‐enlarged classification was associated with higher E/e′, a noninvasive filling‐related marker, but was threshold‐dependent. These findings do not establish diagnostic superiority or prognostic benefit.