Learn The BasicsTransthyretin amyloid cardiomyopathy (ATTR-CM) is a rare and progressive disease characterized by misfolded TTR proteins accumulating in the heart and other parts of the body and causing damage.
The TTR protein is found as a 4-unit tetramer. In ATTR-CM, the tetramer dissociates due to the misfolding of the protein, and the TTR monomers stick together and form amyloid fibrils that accumulate in the body.
There are two types of ATTR-CM: hereditary ATTR-CM and wild-type ATTR-CM. In hereditary ATTR-CM, the tetramer dissociates due to a mutation in the TTR gene that causes the protein to misfold. In wild-type ATTR-CM, there is no known mutation in the TTR gene and the dissociation is thought to result from the normal aging process.
Primary care physicians
The first medical professional to suspect you may have ATTR-CM may be your primary care physician. They may reach this suspicion based on your symptoms and your family history.
They may also order tests such as electrocardiography, echocardiography, cardiac magnetic resonance imaging (MRI) and bone scintigraphy to reach a diagnosis.
If the results of these tests increase the suspicion of ATTR-CM, your primary care physician can refer you to a cardiologist or a geneticist for additional testing to confirm the diagnosis and start the management of your disease.
Cardiologists
A cardiologist can help confirm a diagnosis of ATTR-CM.
They will also monitor and treat abnormalities associated with the disease, such as arrhythmias, heart muscle disease, heart block and congestive heart failure, with medication.
Other specialists
The TTR amyloids can accumulate in other parts of the body apart from the heart, such as the peripheral nerves, the eyes, the kidneys and the gastrointestinal tract. So you may also be seen by other specialists such as a neurologist, ophthalmologist, nephrologist, urologist, or gastroenterologist.
Geneticists and genetic counselors
A geneticist can determine whether you have one of the known genetic mutations in the TTR gene associated with ATTR-CM via a genetic test on a blood sample.
If you have a confirmed mutation in the gene, you may be referred to a genetic counselor who can calculate the risk of you having passed on the mutation to your children and their risk of also developing the disease.
Hereditary ATTR-CM is inherited in an autosomal dominant manner. So, if you have a known mutation causing the disease, you have a 50% chance of passing it to your children. However, this does not necessarily mean they will also have ATTR-CM; rather, they have an increased risk of developing the disease.
It is not known whether wild-type ATTR-CM has a genetic component.
Surgeons
In severe cases, a cardiac surgeon may operate on your heart to replace or repair dysfunctional cardiac valves, implant pacemakers, or even perform a heart transplant.
Patients with ATTR-CM may also need a liver transplant to decrease their rate of TTR protein production, as this is the site where the protein is made.