Does mild proximal aortic (aa) enlargement require follow-up?

From the Guidelines

Mild proximal aortic enlargement requires follow-up to monitor for progression and prevent serious complications like dissection or rupture. According to the 2024 ESC guidelines for the management of peripheral arterial and aortic diseases 1, patients with thoracic aortic aneurysms (TAA) who do not meet surgical criteria require chronic follow-up that includes clinical evaluation and imaging techniques. The best imaging modality depends on aneurysm location, with TTE, CCT, or CMR recommended for the aortic root and ascending aorta.

Key Considerations

• Follow-up should be conducted with the same imaging technique and in the same center to ensure consistency and accuracy.
• If a TAA is only moderate in size and remains relatively stable over time, CMR rather than CCT is reasonable to minimize radiation exposure 1.
• The frequency of imaging depends on the baseline diameter and aetiology, with initial imaging required at 6–12 months after diagnosis, and subsequent imaging performed annually if there is no expansion or customized according to the underlying condition 1.

Recommendations

• I recommend scheduling a follow-up imaging study, usually an echocardiogram, CT scan, or MRI, in 6-12 months to monitor for progression.
• Blood pressure control is essential, aiming for levels below 130/80 mmHg using medications like beta-blockers or angiotensin receptor blockers if appropriate.
• Lifestyle modifications are also important, including smoking cessation, moderate aerobic exercise while avoiding heavy weightlifting or isometric exercises, and limiting caffeine intake. The rate of growth is typically 0.1-0.2 cm per year in most patients, but can be faster in those with risk factors such as hypertension, connective tissue disorders, or family history of aortic disease 1.

From the Research

Aortic Enlargement and Follow-up

• The need for follow-up in patients with mild proximal aortic (aa) enlargement is supported by several studies 2, 3, 4, 5, 6.
• A study published in the Journal of Cardiac Surgery found that progression of proximal aorta leading to adverse aortic events after isolated aortic valve replacement in tricuspid aortic valve patients is infrequent 2.
• Another study published in the European Journal of Cardio-Thoracic Surgery found that mild-to-moderate ascending aortic dilatation remains stable in most bicuspid aortic valve patients who underwent isolated aortic valve replacement surgery for aortic valve stenosis at least 10-year post-AVR 3.

Predictors of Aortic Growth

• A study published in the Journal of Hypertension found that aortic z score at baseline was inversely associated with growth rate, and aortic diameter at first visit, demographic and echocardiographic variables were major determinants of aortic diameter at second visit 4.
• A study published in the Annals of Thoracic Surgery found that a non-resected primary tear, Marfan syndrome, elevated systolic blood pressure at follow-up, and absence of beta-blocker therapy were independent predictors of late reoperation 5.
• The same study found that aortic growth between consecutive imaging studies was detected in 18% of intervals, with a mean yearly growth rate of 5.3 +/- 4.5 mm 5.

Risk of Adverse Aortic Events

• A study published in the European Journal of Cardio-Thoracic Surgery found that patients with a bicuspid aortic valve root phenotype are at significant risk of aortic events after isolated aortic valve replacement, with a freedom from aortic events of 81% at 10 years and 51% at 15 years 6.
• The study suggests that simultaneous root/ascending aortic surgery should be strongly considered in such patients 6.
• Another study published in the Journal of Cardiac Surgery found that AVR alone is acceptable and reasonable in patients with mild to moderate proximal aortic dilatation if connective tissue disorders are not present 2.