Growth Trajectories in Ascending Thoracic Aortic Dilation: Classification and Implications for Imaging Surveillance

BackgroundAscending aortic dilation is monitored with serial imaging, yet event rates are very low, with most type A dissections occurring at non-surgical sizes limiting their prevention by prophylactic repair. We aimed to characterize ascending aortic growth trajectories in a real-world population to understand their clinical consequences and better inform surveillance strategies. Methods and ResultsWe retrospectively studied 3,363 adults (median age 62 years; 68 % men) with [≥]2 chest CTA/MRA examinations at a single center. Mid-ascending diameters were extracted from structured reports and clustered with latent profile analysis (LPA). Early (first 3 scans; n= 1,997) and Extended (first 5 scans; n= 757) models each yielded four classes -- Stable, Growth, Dramatic Growth and Non-physiologic. The Stable class was most common across follow-up (74 % Early; 70 % Extended); Growth and Dramatic Growth classes comprised 23% and 2% respectively. Only 1.1 % ever met guideline growth-based criteria for repair, and this small subgroup showed smaller baseline diameters (37.0 mm vs. 40.3 mm, p=0.009). Among patients with Extended follow-up, 80% of those initially Stable remained Stable. Reclassification into a Growth group associated with younger and age and history of Marfan syndrome (50.0% vs 3.0%, p=0.006). Acute type A dissection was rare (0.45 %) and not clearly linked to any trajectory. ConclusionsMost patients with a dilated ascending aorta show negligible growth and very low complication rates. Repeated imaging beyond 3 scans may amplify uncertainty without clear improvements in risk stratification, suggesting that imaging intervals may be safely de-escalated for initially stable patients.