Left Atrioventricular Coupling Index in Health and Disease: A Longitudinal Multicohort Analysis

Area of Science:

• Cardiology
• Medical Imaging
• Biomarkers

Background:

• Left Atrioventricular Coupling Index (LACI) is a novel imaging biomarker for LA-LV coupling.
• Undefined reference thresholds and uncertain predictive value limit LACI's clinical use.

Purpose of the Study:

• Investigate demographic variations and establish reference thresholds for LACI.
• Characterize LACI's relationship with cardiac structure and function.
• Evaluate LACI's incremental predictive value for cardiovascular outcomes.

Main Methods:

• Utilized two large datasets (Healthy Hearts Consortium, UK Biobank) with Cardiovascular Magnetic Resonance (CMR).
• Determined LACI reference thresholds using the 95% prediction interval method.
• Assessed LACI associations with cardiac parameters and incident cardiovascular outcomes (AF, HF) via regression models.

Main Results:

• Higher LACI observed in older individuals, non-White ethnicities, and women.
• Increased LACI associated with poorer LA function and higher LV filling pressures.
• LACI independently predicted incident AF and HF in UK Biobank, with raised LACI indicating higher event probability.

Conclusions:

• LACI is a robust predictor of AF and HF, offering incremental value over existing markers.
• Population-specific reference thresholds facilitate broader clinical implementation of LACI.