Reappraisal of Surgical Threshold in Patients With Ascending Aortic Dilation: Moving Beyond Aortic Diameters?

Indexing ascending aortic dimensions to height, rather than absolute diameters, may better identify at-risk ascending aortopathy (AA) patients who could benefit from earlier surgery.

This study evaluated whether height-indexed aortic dimensions improve long-term risk stratification in AA patients who do not meet current surgical guidelines.

A total of 11,083 patients (68 ± 13 years, 79% men, 28% with bicuspid aortic valve, 2,196 with aortic surgery and 8,887 unoperated) with AA (4-5 cm) diagnosed on echocardiography (2010-2023) were included. Patients with syndromic aortopathy and acute aortic dissection/rupture at presentation were excluded. The maximum AA diameter, AA height index (AHI) (cm/m), and AA cross-sectional area-to-height (CSAH) (cm²/m) index were calculated. The primary outcome was mortality.

The mean AA diameter, AHI, and CSAH were 4.4 ± 0.2 cm, 2.53 ± 0.3 cm/m, and 8.8 ± 1 cm²/m, respectively. At 6 ± 4 years, there were 84 (8.3%) deaths in the operated group and 1,058 (11.9%) in the unoperated group. There were 128 aortic dissections (1.4%) and 4 aortic ruptures (0.04%) in the unoperated group. Dividing the unoperated sample into a derivation cohort (n = 3,887), spline analysis demonstrated an increase in hazard for death in women with AA diameter ≥4.5 cm and in all patients with AHI ≥2.5 cm/m or CSAH ≥9 cm²/m. Validation in a separate cohort (n = 5,000) confirmed that AHI ≥2.5 cm/m and CSAH ≥9 cm²/m were associated with higher long-term mortality (both P < 0.05).

Indexing AA dimensions to height better identifies high-risk AA patients, particularly women, who fall below surgical criteria. Further studies are needed to determine if this cohort may benefit from earlier intervention at lower size thresholds.