Aortic length indexed to body size was associated with mortality risk in patients with ascending thoracic aortic aneurysm. In a study presented at the  American Heart Association (AHA) 2025 Scientific Sessions, indexing aortic length to BSA improved mortality risk stratification compared with raw aortic length or height-indexed measures.

This retrospective cohort analysis included 449 veterans with aTAA measuring at least 4.0 cm who underwent contrast computed tomography imaging. Patient-specific three-dimensional reconstructions were used to measure aortic length along the centerline from the aortic annulus to the innominate artery. Associations with all-cause and aortic-related mortality were assessed using Fine–Gray competing risk regression models adjusted for age, aortic diameter, and established aTAA risk factors.

Neither raw aortic length nor aortic length indexed to height was associated with all-cause or aortic-related mortality. In contrast, aortic length indexed to BSA showed a significant association with all-cause mortality in univariate analysis (P = 0.0014) and multivariable analysis (P = 0.023).

Optimal length/BSA thresholds were identified at 63 cm/m² overall, 61 cm/m² for 5-year mortality, and 67 cm/m² for 10-year mortality. Patients with aortic length/BSA values above 63 cm/m² demonstrated significantly reduced survival compared with those below this threshold (P < 0.0001).

These findings indicate that indexing aortic length to BSA identifies mortality risk not captured by aortic diameter or unindexed length alone. A BSA-based length index may enhance risk stratification in aTAA, although weight-related variability warrants further investigation.