Amyloid heart disease occurs when amyloid fibrils build up in the heart, making it more difficult for the heart to pump blood around the body. Eventually, this can lead to heart failure.
People can either inherit amyloid heart disease or develop it in the later stages of their life. Treatment for the condition usually involves medications, chemotherapy, and immunotherapy. These can help prevent complications such as heart failure.
Another name for this condition is cardiac amyloidosis.
This article will discuss amyloid heart disease, including its symptoms, causes, diagnosis, risk factors, and treatment options.
Amyloid heart disease, or cardiac amyloidosis, is
In people with amyloid heart disease, an abnormally folded protein — amyloid fibrils — builds up in the heart. This impairs the heart’s ability to function as it should. The heart has to work harder to pump blood around the body, but over time, this can damage the organ or cause heart failure.
Amyloid fibrils can also deposit in other parts of the body, so a person can have amyloidosis in other organs too.
Amyloid transthyretin (ATTR) and light chain (AL) amyloidosis are the two
Other types include:
- dialysis-related amyloidosis
- apolipoprotein A-IV amyloidosis
- gelsolin amyloidosis
- serum protein A amyloidosis
- apolipoprotein A-I amyloidosis
- apolipoprotein A-II amyloidosis
- fibrinogen-α (alpha) amyloidosis
Amyloid fibrils can build up in the heart
ATTR amyloidosis
In ATTR amyloidosis, a protein — transthyretin — misfolds and forms amyloid fibrils that can build up in many organs, including the heart.
ATTR amyloidosis can be hereditary (hATTR) or wild-type (wtATTR). For hATTR, a genetic mutation predisposes transthyretin to change. wtATTR has associations with aging.
AL amyloidosis
AL amyloidosis happens when plasma cells in the bone marrow produce too many immunoglobulin light chains. The light chains make up antibodies, or immunoglobulins, which play a role in the body’s immune system. Amyloid fibrils relating to light chains can build up in organs,
Amyloid heart disease can lead to a range of symptoms.
Symptoms that relate to the heart
- chest pain
- exertion
- shortness of breath
- muscle weakness
- lightheadedness and fainting
- palpitations
When amyloid proteins build up in other parts of the body, a person can experience the
- stomach pain or heartburn after eating
- nausea
- diarrhea
- constipation
- decreased appetite
- carpal tunnel syndrome that may occur on both sides
- erectile dysfunction
- enlarged tongue
- discoloration around eyelids
- buildup of fluid in the body, such as ascites or swelling in the legs
- neuropathy or nerve damage
- low blood pressure when standing (orthostatic hypotension)
- gastrointestinal bleeding
End-stage cardiac amyloidosis
A person with end-stage cardiac amyloidosis may experience the
- breathing difficulties
- extreme fatigue
- abdominal swelling and pain
- unexplained and severe weight loss
- irregular heartbeat
- kidney or liver dysfunction or failure
Doctors usually perform
- an electrocardiogram — which assesses the heart’s electrical activity
- a complete blood count — which checks for markers of heart disease
- a heart MRI — which assesses the structure and function of the organ
- genetic testing — to rule out any heritable conditions that may cause similar symptoms
- a heart ultrasound or echocardiogram
- a heart tissue biopsy
If doctors suspect that amyloid buildup is affecting other organs, they may order the following tests:
- nerve conduction study
- bone marrow biopsy
- nuclear medicine technetium pyrophosphate — which is a specialized test
The treatment for amyloid heart disease
AL amyloidosis
People with AL amyloidosis may receive a combination of immunotherapy and chemotherapy. This treatment approach aims to reduce the number of plasma cells and suppress the further production of light chains.
Stem-cell transplantation may also be an option.
ATTR amyloidosis
The treatment for people with ATTR amyloidosis focuses on stabilizing transthyretin and reducing the amount the body produces.
It usually involves medications such as ATTR stabilizers to prevent the breakdown of transthyretin and ATTR silencers, which decrease the liver production of transthyretin.
In advanced cases, doctors may suggest organ transplantation.
Symptoms
If a person is experiencing cardiac symptoms or complications, a doctor may recommend:
- lifestyle changes, such as reducing salt intake
- other medications, including anticoagulants if a person has atrial fibrillation
- diuretics or water pills
- heart transplantation
A person taking any medications for heart issues requires close monitoring by a healthcare professional.
Generally, people with ATTR amyloidosis have a better outlook than people with the AL type. However, this
The average life expectancy of people with untreated AL amyloidosis is
Individuals with AL amyloidosis who undergo stem-cell transplantation can extend their life, as the 4-year survival rate with this treatment is higher than 90%.
Survival rate
Survival rate refers to the number of people who are still alive for a specific length of time after a particular diagnosis.
For example, a 5-year survival rate of 50% of people means that half of the people are still alive at least 5 years after diagnosis.
If a person notices any symptoms of amyloid heart disease,
Receiving a diagnosis of amyloid heart disease earlier and getting appropriate treatment can improve outlook and reduce the risk of complications, such as heart damage and failure.
Amyloid heart disease causes a buildup of misshapen proteins, known as amyloid proteins, in the heart. These proteins can make it more challenging for the heart to pump blood around the body and, over time, damage the heart.
AL and ATTR amyloidosis are the most common types of amyloid heart disease. Some types are inherited, while others have links to certain conditions, such as bone or blood cancer. An early diagnosis and appropriate treatment can help improve outlook and life expectancy.