Why is the heart damaged by Marfan syndrome?

This is an automatically translated article.

The article was professionally consulted with Master, Doctor Nguyen Minh Son - Interventional Cardiologist - Department of Medical Examination & Internal Medicine - Vinmec Nha Trang International General Hospital.

1. Concept of Marfan . syndrome

Marfan syndrome is an inherited disorder of the connective tissue that damages the heart, blood vessels, eyes, lungs, skeleton, and ligaments. The inheritance in Marfan syndrome is autosomal dominant.
The cause of Marfan syndrome is a defect in the gene that produces connective tissue protein - a protein that gives elasticity and strength to connective tissues in the body. Most people with Marfan syndrome inherit the abnormal gene from their father and/or mother. This means that if a person has a parent who carries the gene that causes the disease, then he or she has a 50% chance of developing the disease (due to inheriting the defective gene). Although Marfan syndrome is a familial disorder, this genetic abnormality can also emerge as a result of a genetic mutation. About 25% of people with Marfan syndrome are caused by a new gene mutation that is not inherited from a parent. Marfan syndrome affects both men and women equally, occurring in all ethnic and racial groups.

2. Symptoms of Marfan . Syndrome

People with Marfan syndrome may develop symptoms soon after birth, in adolescence, adulthood, or never at all. The symptoms and signs of Marfan syndrome vary widely, even among members of the same family. Some people have only mild symptoms, but others develop life-threatening heart and blood vessel complications. In most cases, the disease tends to get worse with age.
Symptoms of Marfan syndrome include:
Tall and slim build. Bones: kyphosis, long arms and legs, disproportionately long fingers and toes, thumb sign, flat feet. High arched palate and thick teeth. Cardiac: fatigue, dyspnea, chest pain, palpitations, syncope due to aortic aneurysm, heart murmur due to regurgitation. Dissection or rupture of the aorta causes massive bleeding, severe ischemia of all organs, and rapid death without prompt emergency surgery. In addition, the risk of infective endocarditis is also increased in people with Marfan syndrome. Lungs: The spine is curved and the sternum is concave or protruding outside, which interferes with breathing, so the patient will feel short of breath, short of breath, breathing is limited, even with light or moderate activity. In addition, people with Marfan syndrome are also at increased risk for emphysema, chronic obstructive pulmonary disease, atelectasis, and sleep apnea. Eyes: lens misalignment, retinal detachment or tear, severe myopia, glaucoma. Symptoms can vary from light sensitivity, glare, and eye pain to blurred vision and blindness. Watch now: Heart damage due to Marfan syndrome

3. Mechanism of heart damage of Marfan syndrome

Heart disease is the most dangerous complication of Marfan syndrome, which includes ruptured aortic aneurysms and damage to the heart valves.

3.1. Dissecting aortic aneurysm

The structural abnormalities of the arteries in Marfan syndrome are caused by a lack of certain proteins involved in the construction of connective tissue, making the structure of the middle coat of the arteries, especially the aorta, not tight. , which weakens the aorta, leading to dilation, aneurysm, or dissection of the aorta. The dilation usually begins at the base of the aorta, causing aortic regurgitation, producing a diastolic murmur. The pressure of the blood causes the artery wall to bulge, spreading along the length of the thoracic and abdominal aorta. When high blood pressure tears the inner lining of the aortic wall, blood flows between the layers of the vessel wall. This condition is called aortic dissection. Weakened vessel wall structure leads to rupture of the aorta.
The risk of rupture of an aortic aneurysm is higher the larger the size of the aneurysm. Approximately 80% of patients with abdominal aortic aneurysms progress to a progressive deterioration over time. Approximately 15-20% of cases progress rapidly (diameter increases by more than 0.5cm per year) and therefore the risk of aneurysm rupture also increases over time. About 25% of patients with ruptured aortic aneurysm die before admission and about 51% of those who die in hospital before surgery. The mortality rate in emergency surgery is about 46% (compared to 4-6% if surgery is prepared in advance). The 30-day survival rate after surgery is about 11%.

3.2. Heart valve disease

People with Marfan syndrome also have an increased risk of problems with their heart valves, such as regurgitation, which can be caused by an altered or less elastic valve structure. When the heart valves are not working properly, the heart muscle has to contract more to compensate. This eventually leads to heart failure.

4. Diagnosis of heart damage due to Marfan . syndrome

Genetic testing. If the clinical criteria for Marfan syndrome are unclear, genetic testing for the mutated FBN1 gene may be useful to confirm the diagnosis. Echocardiography: is the first, simple, easy-to-implement imaging tool for the assessment of cardiac structure and function. Echocardiography shows the size of the heart's chambers and the functioning of the heart's valves. The size and structure of the aorta are also assessed through echocardiography. If an aortic aneurysm has been diagnosed, the patient should have a repeat echocardiogram within 6 to 12 months to assess disease progression. Cardiac magnetic resonance imaging (CMR) or computed tomography of the heart for imaging studies, measuring the size of the entire aorta.

5. Treatment of Marfan . syndrome

Treatment of Marfan syndrome is mainly prevention and treatment of complications of the disease.
For very tall female patients, taking estrogen and progesterone to initiate puberty at 10 years of age may help reduce adult height. All patients with Marfan syndrome should receive beta-blockers (eg, propranolol, atenolol) to prevent cardiac complications. The drug will reduce blood pumping pressure through reducing myocardial contractility; thereby preventing or reducing the progression of aortic dilatation and reducing the risk of arterial dissection and rupture. If the side effects of beta receptor blockers, ACE inhibitors, angiotensin receptor blockers (ARBs) or calcium channel blockers can also be used in people with the syndrome, if the side effects cannot be tolerated. Marfan syndrome. Indications for prophylactic surgery are when the diameter of the ascending aortic aneurysm is ≥ 5.5 cm and the diameter of the descending aorta is ≥ 6 cm. If the patient is at high surgical risk, aortic diameter > 6-7 cm is indicated. In patients with Marfan syndrome with a family history of aneurysms, aortic dissection, or bicuspid aortic valve, there is an increased risk of aortic dissection and rupture. Therefore, the indication for surgery for thoracic aortic aneurysm in these patients may be earlier, when the aortic diameter is > 5 cm. In Marfan syndrome patients with aneurysm diameter > 4.5 cm associated with particularly high risk such as rapidly progressive aortic dilatation, earlier surgery may be indicated to prevent life-threatening rupture. . Pregnant women with Marfan syndrome are at increased risk of developing aortic complications, so elective aortic repair should be discussed before pregnancy. Severe aortic regurgitation may also require surgical repair or valve replacement. Prophylaxis of infective endocarditis in patients with a history of endocarditis or who have undergone prosthetic valve replacement, prior to invasive procedures such as dental or surgical procedures. Scoliosis requires wearing a rigid belt for as long as possible, but surgical intervention is recommended in patients with a spinal curvature between 40 and 50°. Reasonable lifestyle, play light-intensity sports, do not carry heavy objects, avoid excessive exertion to reduce the burden on the heart. It is recommended that all patients with Marfan syndrome undergo regular medical examination at least once a year to treat symptoms (if any), monitor disease progression, and detect cardiac and ocular complications early. , lungs, bones,... Genetic counseling. Heart damage from Marfan syndrome is a "variably expressed" genetic disorder. That is, signs and symptoms can vary from person to person. They can also vary in severity and can range from mild to life-threatening. Symptoms tend to get worse as you get older. Therefore, regular check-ups at reputable medical facilities are very important for patients.
Currently, Cardiovascular Center - Vinmec International General Hospital is one of the leading centers in the country for examination, diagnosis, screening and treatment of cardiovascular diseases. Vinmec not only has the convergence of a team of experienced and reputable leading experts in the field of surgical, internal medicine, interventional cardiac catheterization but also has a system of modern equipment, on par with the most prestigious hospitals in the world. In particular, with a space designed according to 5-star hotel standards, Vinmec ensures to bring patients the most comfort, friendliness and peace of mind.

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