From the Guidelines
Aortic root dilation in Marfan syndrome is a serious condition that significantly increases the risk of aortic dissection or rupture, and surgical intervention is recommended at a threshold of ≥5.0 cm diameter.
Implications of Aortic Root Dilation
- The risk of aortic dissection or rupture is high in patients with Marfan syndrome, with virtually every patient having evidence of aortic disease at some point during their lifetime 1.
- Aortic root dilation is the most common cardiovascular manifestation of Marfan syndrome, and the severity of the aortic disease is related to the degree and segment length of aortic dilatation 1.
- The threshold for surgical repair of the aortic root is typically an external diameter of 5.0 cm, although factors such as rapid growth, family history of aortic dissection, and significant aortic regurgitation may prompt repair at a smaller diameter 2.
- Beta blockade is recommended to slow the rate of aortic dilatation and reduce the cumulative incidence of cardiovascular complications 3.
Monitoring and Management
- Annual imaging is recommended for patients with Marfan syndrome if stability of the aortic diameter is documented, with more frequent imaging considered if the maximal aortic diameter is 4.5 cm or greater, or if the aortic diameter shows significant growth from baseline 4.
- Echocardiogram is recommended at the time of diagnosis and 6 months thereafter to determine the rate of enlargement of the aorta 4.
- Surgical repair of the dilated aortic root/ascending aorta is usually performed at a threshold of an external diameter of 5.0 cm, with factors such as rapid growth, family history of aortic dissection, and significant aortic regurgitation prompting repair at a smaller diameter 2.
From the Research
Implications of Aortic Root Dilation in Marfan Syndrome
The implications of aortic root dilation in Marfan syndrome are significant and can lead to severe complications. Some of the key implications include:
- Aortic dissection: Aortic root dilation can lead to aortic dissection, which is a life-threatening condition where the inner layer of the aorta tears, causing blood to flow between the layers of the aorta 5.
- Aortic regurgitation: Aortic root dilation can also lead to aortic regurgitation, where the aortic valve does not close properly, allowing blood to flow back into the left ventricle 5.
- Increased risk of aortic events: Patients with Marfan syndrome and aortic root dilation are at increased risk of aortic events, such as dissection, rupture, or elective surgery 6.
- Association with fibrillin-1 variants: Aortic dilatation in Marfan syndrome has been associated with fibrillin-1 variants, particularly 'dominant negative' mutations 7.
Predictors of Aortic Complications
Several factors have been identified as predictors of aortic complications in Marfan syndrome, including:
- Initial aortic root size: The size of the aortic root at the time of diagnosis is a significant predictor of aortic complications 5.
- Generalized aortic dilation: Generalized aortic dilation, which involves the supraaortic ridge and proximal ascending aorta, is a potent marker of increased risk for subsequent aortic complications 5.
- Age: Older age is associated with an increased risk of aortic complications 5.
- Systolic blood pressure: Higher systolic blood pressure is associated with an increased risk of aortic complications 5.
- Aortic growth rate: A faster rate of aortic growth is associated with an increased risk of aortic complications 5.
Monitoring and Management
Regular monitoring and management of aortic root dilation in Marfan syndrome are crucial to prevent complications. This includes:
- Annual echocardiographic examinations: Patients with Marfan syndrome should have annual echocardiographic examinations to monitor aortic root dimensions 8.
- Beta-adrenergic blocking drugs: Patients with Marfan syndrome and aortic dilatation may be advised to take beta-adrenergic blocking drugs to retard the rate of aortic dilatation 8.
- Elective composite graft repair: Patients with rapid progression of aortic dilatation or an aortic root diameter in excess of 50 mm may be considered for elective composite graft repair of the aorta 8.