Ethnic variation in thoracic aortic dimensions in the general population: a comparison between Indian and Dutch...

Aortic dimensions are critical for assessing the risk of acute aortic complications and guiding surgical interventions. Current guidelines define absolute diameter thresholds based largely on Western cohorts, while data on Indian patients remain limited. To address this gap, our study provides a direct, large-scale comparison of aortic diameters between Indian and Dutch individuals to determine whether existing geometry-based surgical guidelines are equally applicable across populations.

In this retrospective cohort study, we analysed all consecutive patients who underwent CT imaging between January and December 2022 at SIMS Hospital (India) and Amsterdam University Medical Center (Netherlands). Aortic diameters were measured at five predefined anatomical locations: aortic root, ascending aorta, aortic arch, descending aorta and abdominal aorta. Multivariable linear regression models were used, adjusting for age, sex, height and comorbidities.

A total of 3692 patients were included (2000 Indian and 1692 Dutch). Indian patients had a larger aortic root (33.9 ± 4.6 mm vs 31.5 ± 5.4 mm; p<0.001), whereas Dutch patients had significantly larger diameters of the ascending aorta (33.1 ± 5.4 mm vs 30.5 ± 4.3 mm; p<0.001), aortic arch (29.8 ± 4.5 mm vs 26.4 ± 3.7 mm; p<0.001), descending aorta (26.7 ± 4.2 mm vs 23.0 ± 3.9 mm; p<0.001) and abdominal aorta (23.1 ± 5.0 mm vs 21.3 ± 3.4 mm; p<0.001). These differences persisted after adjustment for age, sex, height and comorbidities.

In this first global comparison of ascending aortic dimensions between Indian and Dutch patients, we demonstrate substantial geographic heterogeneity. These findings highlight concerns about applying current surgical thresholds to Indian patients with aortopathy and emphasise the need for individualised risk assessment and treatment strategies in this population. Future guidelines should consider population-specific differences in India and incorporate indexed measurements to optimise personalised surgical decision-making.