Introduction

Marfan syndrome is a condition that affects the connective tissues in the body, which are responsible for maintaining the body's structural integrity and supporting internal organs and other tissues. It is caused by a mutation in the fibrillin-1 (FBN1) gene, which is partly responsible for the structure of connective tissues. Marfan syndrome causes complications in various different body systems, such as the integumentary (e.g., hair, skin and nails), skeletal (e.g., bones and joints), cardiovascular (e.g., heart and blood vessels), respiratory (e.g., lungs) and nervous (e.g., ocular) systems.¹ Despite this, most health complications and deaths related to Marfan syndrome are caused by cardiovascular complications.²

Marfan syndrome is a rare condition, affecting approximately 1 in 5000 people in the UK. However, it remains one of the more common disorders affecting connective tissues.³ Both people assigned male at birth (AMAB) and people assigned female at birth (AFAB) are equally likely to inherit Marfan syndrome. If a parent has Marfan syndrome, there is a 50% chance that their child will inherit the syndrome. In 25% of cases, neither parent has Marfan syndrome. In these situations, the genetic mutation responsible for Marfan syndrome occurs for the first time in either the egg or the sperm. Once the gene that has suffered mutation is passed on to the child, they will develop Marfan syndrome.^4,5

Signs and symptoms of Marfan Syndrome

As connective tissue is present throughout the body, signs and symptoms of Marfan syndrome may appear anywhere. These may include:

• Arms, legs, fingers, and toes that are disproportionately long
• Flat feet
• A condition where the sternum (chest wall) either caves inward (pectus excavatum) or protrudes outward (pectus carinatum)
• Curvature of the spine
• Headaches
• Fast or intense heartbeat
• Loose joints
• A long, narrow face
• Back pain
• Leg numbness
• Breathing difficulties
• Stretch marks on the skin
• Vision problems particularly blurry vision and near-sightedness^3,4,6

Cardiovascular complications in patients with Marfan Syndrome

The weakened connective tissue caused by the FBN1 gene mutation causes various cardiovascular issues. Most are related to the aortic artery and the valves in the heart. These issues can lead to severe conditions such as aortic aneurysms, aortic dissections, and valvular deficiencies. Although these issues can occur at any point, they usually worsen with age.⁵

Aorta-related complications

The aorta is the biggest and most important artery in the body. It is responsible for transporting blood from the heart to the whole body. Complications with the aorta are vast and typically life-threatening. Some examples include:

• Aortic aneurysm: The aorta, especially the ascending aorta, is more susceptible to dilation and aneurysm formation in individuals with Marfan syndrome as its weaker wall causes progressive enlargement. If not treated, this typically progresses to an aortic aneurysm, a distention of the artery that may rupture. The rupture of an aortic aneurysm is always a life-threatening situation and a medical emergency
• Aortic dissection: Aortic dissection is also life-threatening and occurs when there is a tear in the inner layer of the aorta, allowing blood to flow between the layers of the aortic wall. This pressure can lead to rupture, which is almost always fatal. Similar to an aortic aneurysm, people with Marfan syndrome have a higher risk of aortic dissection, particularly in the ascending aorta
• Aortic root dilatation: Aortic root dilatation refers to the widening of the aortic root, which is the part of the aorta that is connected to the heart. This condition can lead to aortic valve insufficiency, where the aortic valve fails to close completely, causing blood to flow back into the heart. If not properly managed, this can eventually result in heart failure

Valve-related complications

Some examples of valve-related complications, experienced more commonly amongst those with Marfan syndrome, are listed below:

• Valve Prolapse: Marfan syndrome can affect the mitral valve, which is situated between the left atrium and left ventricle. The valve leaflets (e.g., flaps) may become unusually thick and bulge back into the left atrium during heart contractions (e.g., systole), causing mitral valve regurgitation. This backflow of blood can lead to symptoms like palpitations, shortness of breath, and fatigue
• Tricuspid Valve Prolapse: Although it is somewhat less common, Marfan syndrome can also impact the tricuspid valve, causing it to prolapse and leading to tricuspid valve regurgitation^1,4,5

Diagnosing cardiovascular complications

Timely and precise diagnosis of cardiovascular complications in Marfan syndrome is essential for effective management and preventing severe consequences. The main methods for diagnosis include:

• Echocardiography: Echocardiography is the most commonly used imaging method for assessing the size of the aorta and the function of the heart valves. Regular echocardiographies are advised to track any changes in the aorta and heart valves
• MRI and CT Scans: Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) scans offer detailed images of the aorta and other blood vessels, aiding in the identification of aneurysms, dissections, and other vascular abnormalities
• Genetic testing: Detecting mutations in the FBN1 gene can confirm a diagnosis of Marfan syndrome and assist in evaluating the risk of cardiovascular complications
• Clinical criteria: The Ghent criteria are a set of diagnostic guidelines used to diagnose Marfan syndrome by considering a combination of clinical features, family history and genetic testing^2,3,4

Treatment and prevention of cardiovascular complications

The management of cardiovascular complications in Marfan syndrome involves a combination of pharmacological, surgical and lifestyle interventions. It mainly revolves around decreasing the risk of aortic dissection and effective management of valvular insufficiencies.

Pharmacological measures

Some commonly used pharmacological measures for addressing cardiovascular complications of Marfan syndrome include:

• Beta-Blockers: These medications decrease the speed of aortic dilatation as they reduce the strength of the heart's contractions; thus, the stress applied on the aortic wall
• Angiotensin Receptor Blockers (ARBs): ARBs (e.g., irbesartan, valsartan, losartan and candesartan) have been shown to reduce the aortic growth rate in individuals with Marfan syndrome by blocking the effects of transforming growth factor-beta (e.g., TGF-β), a protein that contributes to aortic enlargement
• Other Antihypertensives: Maintaining blood pressure within adequate ranges is vital in reducing stress on the aorta. ARBs contribute to treating high blood pressure but additional hypertensive medication may be required

Surgical management

Surgical management remains an option for more severe cases of Marfan syndrome. Examples of surgical procedures used to address these cardiovascular complications include:

• Aortic root replacement: This surgery is advised for individuals with substantial aortic root enlargement or those at high risk of dissection. During the procedure, the enlarged section of the aorta is replaced with a synthetic graft, and the aortic valve may be repaired or replaced as required
• Valve repair or replacement: In cases of severe mitral or tricuspid valve regurgitation, it may be necessary to surgically repair or replace the affected valve to prevent heart failure

Lifestyle and preventive measures

Prevention (and early detection) still remains better than cure. To help manage complications of Marfan syndrome and to sooner identify symptoms indicative of more serious issues, the following lifestyle and preventative measures should be employed:

• Regular cardiovascular monitoring to detect changes in aortic dimensions and valvular function in a timely manner
• Regular eye exams using a slit-lamp to check for lens dislocation
• Close monitoring of bone development, especially during childhood and teenage years
• Avoid strenuous physical activities and contact sports to reduce the risk of aortic dissection. Engaging in moderate, low-impact activities such as walking is usually advised
• Pregnancy presents additional risks for people AFAB with Marfan syndrome due to increased cardiovascular strain. Individuals should undergo counselling and close monitoring before and during pregnancy, and receive coordinated care from cardiology and obstetric teams throughout and following pregnancy^2,3,5

Ongoing research

Ongoing research is advancing our understanding of Marfan syndrome and how to better manage its cardiovascular complications. Key areas of focus include:

1. Genetic therapies: Gene editing and therapy are being researched as a means of correcting the genetic mutations that underlie Marfan syndrome. Although these treatments are still experimental, they hold potential in offering curative options in the future
2. Targeted molecular therapies: Research into molecular pathways – such as the TGF-β signalling pathway – has led to the development of targeted therapies that aim to modify the biological processes involved in the formation and progression of aortic aneurysms
3. Improved surgical techniques: Innovations in surgical techniques and materials are continuously improving outcomes for aortic and valvular surgeries. Minimally invasive approaches and more durable graft materials are being developed to enhance patient recovery and improve long-term prognosis
4. Long-term outcome studies: Long-term studies of individuals with Marfan syndrome are crucial for understanding the natural course of the disease and assessing the efficacy of different treatments. These studies are key to refining clinical guidelines and enhancing overall patient care^1,5

Summary

• Marfan syndrome is a rare chronic disease that affects the body’s connective tissues
• The most severe consequences of Marfan syndrome are often a product of complications in the cardiovascular system
• Early diagnosis and holistic management are vital to preventing life-threatening complications such as aortic dissection and severe valvular insufficiencies
• Regular monitoring, appropriate pharmacological therapy, timely surgical interventions, and lifestyle modifications are the foundation for appropriate disease management
• New research brings promise for a variety of novel surgical improvements and potentially curative gene editing treatments that may, in the future, greatly improve the quality of life for those with Marfan syndrome