Defining left ventricular remodeling using lean body mass allometry: a UK Biobank study

Area of Science:

• Cardiology
• Biomedical Engineering
• Physiology

Background:

• Ventricular remodeling is assessed using indexed left ventricular mass (LVM), end-diastolic volume (LVEDV), and concentricity, often via mass-to-volume ratio (MVR).
• Accurate scaling of these parameters is crucial for classifying geometric patterns of ventricular remodeling.

Purpose of the Study:

• To validate lean body mass (LBM)-based allometric coefficients for scaling cardiac parameters.
• To determine a novel index of left ventricular concentricity (LVC) that is independent of both LVEDV and LBM.

Main Methods:

• Utilized UK Biobank participants (n=1638) with cardiac magnetic resonance (CMR) and dual-energy X-ray absorptiometry (DXA) data.
• Determined allometric coefficients for scaling LVM and LVEDV using linear regression on logarithmically transformed parameters.
• Defined a multiplicative allometric relationship for LVC, adjusting for LVEDV and LBM.

Main Results:

• Validated LBM allometric coefficients (0.85 ± 0.06 for LVM, 0.85 ± 0.03 for LVEDV) in subjects with lower body fat.
• Found MVR was independent of LBM but negatively associated with LVEDV in both sexes.
• Developed LVC (LVM/(LVEDV^0.40 × LBM^0.50)), which was independent of LVEDV and LBM, increasing overlap between LV hypertrophy and concentricity.

Conclusions:

• Successfully validated LBM-based allometric coefficients for scaling CMR-indexed parameters.
• The novel LVC index offers an improved, volume- and LBM-independent measure for assessing ventricular remodeling.