What is cardiac amyloidosis?
Cardiac amyloidosis is a rare condition in which amyloid protein deposits build up in the heart. The condition can be either inherited (passed down from parent to child) or wild-type, which occurs with aging and is not inherited.
What is amyloid protein?
Amyloid protein is a naturally occurring protein in the body, it is produced in the liver, to provide transport for thyroxine (a hormone) and retinol (a form of vitamin A).
What are the 2 types of ATTR amyloidosis?
The two types are:
Hereditary ATTR – This occurs due to a change in the gene that produces transthyretin (TTR) protein. The faulty TTR forms abnormal amyloid fibrils, which accumulate in various organs, including the heart.
Wild-type ATTR – In this form, normal TTR protein misfolds, leading to amyloid deposits, commonly in the heart. This type is not inherited and typically occurs with aging.
What are the symptoms of cardiac amyloidosis?
Cardiac symptoms may include:
- Feeling short of breath- when exercising or at rest
- Palpitations (feeling your heart beating or fluttering in your chest or neck)
- Ankle or leg swelling or feeling your tummy is swollen or bloated
- Fatigue- feeling extremely tired
- Chest pain
- Feeling lightheaded or faint
How is cardiac amyloidosis diagnosed?
Diagnosis can take time, as many people present with symptoms of heart failure, which are treated, while the underlying cause may be difficult to identify. Investigations may include blood tests, an echocardiogram, an electrocardiogram (ECG), a cardiac MRI scan, and a DPD scan (a special scan that uses a tracer to detect amyloid in the heart). Genetic testing may be recommended if hereditary ATTR is suspected.
How is cardiac amyloidosis treated?
Cardiac amyloidosis treatment may include medications prescribed for heart failure symptoms which might include a SGLT2 inhibitor (dapagliflozin or empagliflozin), loop diuretics (furosemide, bumetanide) and/or betablockers for heart rhythm.
Medications which stabilise the TTR protein by binding to it (tafamidis and acoramadis), have been shown to help slow progression of the condition in some people. Gene silencers work by stopping the gene from making the abnormal protein (Vatrisiran and Eplontersen) and so reduce the amount of abnormal TTR in the body.
Supportive treatment may also be advised for some people including changes to lifestyle.
Heart or liver transplant may be advised for some people.
Please note:
*There is a 3 rd type of amyloidosis which can cause cardiac amyloidosis, Amyloid Light chain (AL) amyloidosis. This type starts in the bone marrow (which makes too much AL) and can affect the heart or kidneys.
*Generalised symptoms of amyloidosis can also include carpel tunnel syndrome, joint, spine, nerve or digestive system symptoms.