Misdiagnosis of transthyretin amyloid cardiomyopathy (ATTR-CM) is relatively common, with a correct diagnosis sometimes taking as long as four years.
The subsequent delay in treatment can have serious consequences for a patient as symptoms are left untreated, and the disease progresses unchecked. That can negatively affect a patient’s quality of life and shorten life expectancy.
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.
The availability of more advanced diagnostic tests in recent years has led to shorter delays in patients receiving the correct diagnosis of ATTR-CM.
Read more about ATTR-CM testing and diagnosis
Delays in diagnosing ATTR-CM
ATTR-CM is a rare disease of the heart muscle, and as a result, it is often underrecognized and overlooked in patients. There are other factors that contribute to the frequent misdiagnosis of ATTR-CM, including the following.
- Symptoms that overlap with other conditions.
- Nonspecific symptoms.
- A lack of awareness around the disease.
- Few accurate diagnostic tools until recently.
Early identification and treatment of ATTR-CM is essential to effectively manage symptoms and slow disease progression. If left untreated or incorrectly treated, the symptom burden becomes heavier, and the disease develops into heart failure, which is ultimately fatal.
Common misdiagnoses in ATTR-CM
The most common symptoms of ATTR-CM include shortness of breath, palpitations, irregular heartbeat, fatigue, bloating, swelling of the legs and feet, coughing and wheezing, and brain fog or confusion. The symptoms are similar to those of heart failure.
This is a key reason why ATTR-CM is often mistaken for other cardiac-related conditions, such as heart failure with preserved ejection fraction, hypertensive cardiomyopathy, aortic stenosis, hypertrophic cardiomyopathy and AL amyloidosis.
In addition, there are two subtypes of ATTR-CM, which present with slightly different sets of symptoms.
Symptoms of hereditary ATTR-CM (hATTR-CM) can be cardiac-related and also include numbness and prickling or tingling in the feet, hands, legs and arms.
Symptoms of wild-type ATTR-CM (wATTR-CM), the most common type and associated with aging, can be slow to appear. Patients with wATTR-CM may experience carpal tunnel syndrome and lower back pain as amyloid deposits build up in the wrists and spine, as well as cardiac-related symptoms.
This mix of symptoms can make ATTR-CM difficult to diagnose.
Achieving a correct diagnosis in ATTR-CMs
In diagnosing ATTR-CM, your doctor will look at your family medical history and assess your symptoms. He or she will also conduct noninvasive diagnostic tests to differentiate ATTR-CM from other similar diseases on the way to a correct diagnosis. The tests may include the following.
- Electrocardiogram (ECG): A noninvasive test that records the electrical activity of the heart.
- Echocardiogram: An ultrasound test that checks for anomalies in the structure of the heart.
- Cardiac magnetic resonance imaging (CMR): A noninvasive, highly sensitive scan of heart structure and blood flow.
- Nuclear imaging: A noninvasive, highly accurate bone scan.
- Genetic testing: A test to distinguish between wATTR-CM and hATTR-CM once your diagnosis is confirmed.
