Transthyretin amyloid cardiomyopathy (ATTR-CM) is a rare disease of the heart muscle. As a result of a general lack of awareness among health care professionals about the disease, it can be overlooked or misdiagnosed.
This is due in part to the disease’s common symptoms, which mimic those of several other heart-related conditions. These include heart failure related to high blood pressure or hypertension, hypertrophic cardiomyopathy, ischemic heart disease and aortic stenosis. Extensive diagnostic tests are therefore required to make an accurate ATTR-CM diagnosis.
What is ATTR-CM?
Transthyretin amyloidosis cardiomyopathy (ATTR-CM) is a rare progressive disease of the heart muscle that leads to congestive heart failure. It occurs when the transthyretin protein produced by the liver is unstable. Symptoms include fatigue; shortness of breath; irregular heart rate or palpitations; swelling of the legs, ankles and stomach; brain fog; wheezing; and dizziness. It often goes underdiagnosed because of a lack of awareness and knowledge of the disease. There is currently no cure for ATTR-CM.
Common symptoms of ATTR-CM
When amyloid deposits accumulate in the left ventricle of the heart, the heart muscle thickens and stiffens, making it difficult for the heart to pump blood to the body.
Learn more about ATTR-CM testing and diagnosis
The most common symptoms of ATTR-CM are similar to those of heart failure.
- Shortness of breath.
- Fatigue.
- Chest pain.
- Coughing or wheezing.
- Swelling of the legs, ankles and feet.
- Brain fog.
- Increased heart rate.
- Irregular heart rate.
In hereditary ATTR-CM, numbness or tingling in the hands and feet may also occur. In wild-type ATTR-CM, spinal stenosis or carpal tunnel syndrome is possible.
Heart conditions that mimic ATTR-CM
Heart failure due to high blood pressure: The left ventricle becomes enlarged and has difficulty pumping blood. Symptoms are shortness of breath, fatigue, coughing or wheezing, swelling of feet and ankles, brain fog, dizziness and weight gain.
Hypertrophic cardiomyopathy: As in ATTR-CM, the left ventricle becomes thicker, making it harder for the heart to pump blood. Symptoms include fatigue, shortness of breath, chest pain, swelling of the extremities and abnormal heart rhythms. They can be difficult to distinguish from those of ATTR-CM.
Aortic stenosis: The left ventricle is also affected in aortic stenosis, with blood flow restricted to the aorta. Symptoms include chest pain, shortness of breath, rapid heart rate and dizziness.
As you can see, the overlapping symptoms may lead to misdiagnosis in people with ATTR-CM.
Diagnostic tests for ATTR-CM
To ensure an accurate diagnosis, your cardiologist will run a number of tests to either rule in or rule out ATTR-CM.
- Blood and urine tests.
- Electrocardiogram (ECG).
- Echocardiograms, cardiac magnetic resonance imaging or ultrasounds.
- Bone scans.
- Heart tissue biopsy.
If ATTR-CM is confirmed, clinicians may perform genetic testing to identify the subtype, wild type or hereditary.
Timely and accurate diagnosis of ATTR-CM will provide an opportunity to start treatment as soon as possible. There is currently no cure for ATTR-CM, but treatment can help slow disease progression and manage the symptom burden.
