Is follow-up imaging recommended for an ascending aortic root dilation of 3.7cm?

From the Guidelines

Follow-up imaging is recommended for an ascending aortic root dilation of 3.7cm, with annual imaging using either echocardiography, CT, or MRI typically appropriate to monitor for progression. This recommendation is based on the 2024 ESC guidelines for the management of peripheral arterial and aortic diseases, which suggest that follow-up imaging should be considered annually if there is no expansion/extension or customized according to baseline aortic diameter and the underlying condition 1. For a dilation of this size, which represents mild to moderate dilation of the aortic root, there is a risk of further enlargement over time.

Key Considerations

• The frequency of imaging may need to be adjusted based on the rate of growth, with more frequent imaging (every 6 months) if growth exceeds 0.3-0.5cm per year 1.
• Patients should also be advised to maintain good blood pressure control (target <130/80 mmHg), which may require antihypertensive medications such as beta-blockers or angiotensin receptor blockers to reduce hemodynamic stress on the aortic wall.
• Additionally, patients should avoid heavy isometric exercise and activities that involve Valsalva maneuvers, which can transiently increase aortic wall stress.
• The goal of surveillance is to detect significant progression before the aorta reaches dimensions that substantially increase the risk of life-threatening complications like dissection or rupture, which typically becomes more concerning at sizes greater than 5.0-5.5cm.

Imaging Modalities

• The best imaging modality depends on aneurysm location, with TTE, CCT, or CMR recommended for the aortic root and ascending aorta 1.
• CMR or CCT is recommended for surveillance of patients with aneurysm at the distal ascending aorta, aortic arch, or DTA 1.
• 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.

From the Research

Follow-up Imaging for Ascending Aortic Root Dilation

• The decision to perform follow-up imaging for an ascending aortic root dilation of 3.7cm depends on various factors, including the presence of risk factors such as bicuspid aortic valve, connective tissue disorder, or family history of aortic dissections 2.
• According to the study by 2, most American and European societies recommend yearly or biannual imaging of the thoracic aorta with computed tomographic (CT) imaging, magnetic resonance (MRI) imaging, and transthoracic echocardiographic (TTE) examination.
• However, the same study suggests that mild to moderate degenerative thoracic aortic aneurysm has a minimal change in dimensions over time, and current guidelines recommending yearly surveillance imaging of ARD and AAD need to be revisited to allow a more liberal follow-up interval 2.
• Another study found that medical prophylaxis, such as losartan or atenolol, can reduce proximal aortic growth rates in young patients with at least moderate and progressive bicuspid aortopathy 3.
• The use of angiotensin receptor blockers (ARBs) has also been shown to slow down the progression of aortic dilatation in patients with Marfan syndrome 4.
• A study published in the Journal of the American Heart Association found that aortic root dilatation is more malignant than ascending aortic dilation, and that dilation of the aortic root imparts a significant higher risk of adverse events 5.
• In athletes, aortic root disease, including aortic root dilation, anomalous coronary artery, bicuspid aortic valve, and Marfan's syndrome, can lead to life-threatening sequelae, and management decisions should be based on comorbidities, degree of dilation, and rate of progression 6.

Key Considerations

• The presence of risk factors, such as bicuspid aortic valve or family history of aortic dissections, should be taken into account when deciding on follow-up imaging 2, 3.
• The use of medical prophylaxis, such as losartan or atenolol, may be beneficial in reducing proximal aortic growth rates 3.
• Angiotensin receptor blockers (ARBs) may be effective in slowing down the progression of aortic dilatation in patients with Marfan syndrome 4.
• Aortic root dilatation is more malignant than ascending aortic dilation, and dilation of the aortic root imparts a significant higher risk of adverse events 5.