Standardised computed tomographic assessment of left atrial morphology and tissue thickness in humans.

Aims: Left atrial (LA) remodelling is a common feature of many cardiovascular pathologies and is a sensitive marker of adverse cardiovascular outcomes. The aim of this study was to establish normal ranges for LA parameters derived from coronary computed tomographic angiography (CCTA) imaging using a standardised image processing pipeline to establish normal ranges in a previously described cohort.
Methods: CCTA imaging from 193 subjects recruited to the Budapest GLOBAL twin study was analysed. Indexed LA cavity volume (LACV _i ), LA surface area (LASA _i ), wall thickness and LA tissue volume (LATV _i ) were calculated. Wall thickness maps were combined into an atlas. Indexed LA parameters were compared with clinical variables to identify early markers of pathological remodelling.
Results: LACV _i is similar between sexes (31 ml/m ² v 30 ml/m ² ) and increased in hypertension (33 ml/m ² v 29 ml/m ² , p = 0.009). LASA _i is greater in females than males (47.8 ml/m ² v 45.8 ml/m ² male, p = 0.031). Median LAWT was 1.45 mm. LAWT was lowest at the inferior portion of the posterior LA wall (1.14 mm) and greatest in the septum (median = 2.0 mm) (p < 0.001). Conditions known to predispose to the development of AF were not associated with differences in tissue thickness.
Conclusions: The reported LACV _i , LASA _i , LATV _i and tissue thickness derived from CCTA may serve as reference values for this age group and clinical characteristics for future studies. Increased LASA _i in females in the absence of differences in LACV _i or LATV _i may indicate differential LA shape changes between the sexes. AF predisposing conditions, other than sex, were not associated with detectable changes in LAWT. Clinical trial registration: http://www.ClinicalTrials.gov/NCT01738828.
Competing Interests: The authors report no relationships that could be construed as a conflict of interest.
(© 2020 Published by Elsevier B.V.)