Growth Trajectories in Ascending Thoracic Aortic Dilation: Classification and Implications for the Effectiveness of...

Ascending aortic dilation is monitored with serial imaging, yet event rates are low, with type A dissections often occurring at nonsurgical sizes. We aimed to characterize ascending aortic growth trajectories in a real-world population to understand their clinical consequences and better inform surveillance strategies.

We conducted a retrospective, single-center study of adults with ≥2 thoracic computed tomography angiography/magnetic resonance angiography examinations. Midascending diameters from clinical reports were used to analyze real-world surveillance effectiveness. Growth trajectories were clustered using latent profile analysis. Early (first 3 scans; n=1997) and extended (first 5 scans; n=757) latent profile analysis models each yielded 4 classes: Stable, Growth, Dramatic Growth, and Fluctuation (an unstable trajectory attributed to measurement noise).

We studied 3363 adults (median age 62 years; 68% men). Stable class was most common (74% Early; 70 % Extended); Growth and Dramatic Growth classes comprised 23% and 2% respectively. Only 1.1% met guideline growth-based criteria for repair, and this subgroup had smaller baseline diameters (37.0 versus 40.3 mm, P=0.009). At Extended follow-up, 80% of those initially Stable remained Stable. Reclassification into a Growth class was associated with younger age and Marfan syndrome (50.0% versus 3.0%, P=0.006). Acute type A dissection was rare (0.45%) and not clearly linked to any trajectory.

Most patients with a dilated ascending aorta show negligible growth and low complication rates during routine surveillance. Repeated imaging beyond 3 scans may amplify uncertainty without clear improvements in risk stratification, suggesting that imaging surveillance may be safely deescalated for stable patients.