tampa cardiac amyloidosis center

What is cardiac amyloidosis?

Cardiac amyloidosis occurs when waxy, abnormal proteins are deposited in the heart tissue. This causes the heart to stiffen making it difficult for it to relax and accommodate enough blood to meet the body’s needs. This results in heart failure symptoms like fluid retention, leg swelling, abdominal bloating, and shortness of breath.  The amyloid proteins can also infiltrate the electrical system of the heart resulting in palpitations, fatigue, lightheadedness, and other symptoms related to abnormal heart rhythms.

There are two main types of proteins that infiltrate the heart to cause cardiac amyloidosis. The first type of protein is made up of immunoglobulin light chains and this is called AL amyloidosis. This condition can be caused by excess proteins made by certain cancers. We always collaborate with cancer specialists (oncologists) whenever we discover AL amyloidosis because chemotherapy is often required to effectively treat it.

The second type of amyloidosis results from infiltration of the heart by a protein called transthyretin (TTR). This kind of amyloidosis is called ATTR amyloidosis. The TTR protein is normally very useful but sometimes it loses its normal structure and literally begins to unravel leading to a useless protein that is then stored throughout the body, including the heart. Abnormal ATTR leading to cardiac amyloidosis can be inherited as an abnormal gene that produces the abnormal TTR protein. This is called hereditary ATTR. However, in the majority of people with ATTR amyloidosis there is no inherited gene defect and completely normal TTR protein spontaneously becomes unstable and starts to unravel. This is called wild-type ATTR.

Who gets cardiac amyloidosis? 

Cardiac amyloidosis is more common than many doctors and patients realize and is frequently misdiagnosed as regular heart failure. It is estimated that 10-15% of the more than 3 million Americans with heart failure and preserved ejection fraction may have cardiac amyloidosis as the cause.

Cardiac amyloidosis appears to be more common in men than women. It also tends to be more common in Blacks than other ethnicities, although as our population gets older, the ethnic differences are becoming less. Most people who develop cardiac amyloidosis are older but many younger people with the inherited form of ATTR amyloidosis can be as young as 30-40 years of age when symptoms start. Patients with AL cardiac amyloidosis also tend to be younger.

Since anyone with heart failure could potentially have amyloidosis, the most important thing is to consider this diagnosis, especially in an older person with no other obvious explanation for their recurrent heart failure symptoms. 

Special Considerations in Veterans

In May, 2009, the VA began to presume AL amyloidosis is related to herbicide (agent orange) exposure in Veterans. AL amyloidosis can infiltrate and destroy any organ including the heart, kidneys, liver, bowel, skin, nerves, joints, and lungs. Symptoms vary depending on the involved organ. When the heart is involved, cardiac amyloidosis symptoms develop and systematic evaluation is an absolute must in order to sort out whether a Veteran has AL amyloid associated with their service or ATTR amyloid that is inherited or occurred spontaneously.  

Unfortunately, many Veterans with recurrent heart failure suffer for years before they get an accurate diagnosis of cardiac amyloidosis and receive more targeted treatment. Many community-based primary care physicians and cardiologists are unaware of the nuances of amyloidosis in Veterans. At TCAC, our proven systematic assessment and management strategy gets these American heroes the timely care they deserve.

How is cardiac amyloidosis evaluated? 

Evaluation of cardiac amyloidosis can be challenging but you have to suspect it to find it. People who get repeated heart failure symptoms for no good reason should be suspected. People with symptoms way out of proportion to their objective heart problem should also be suspected. Both primary care doctors and cardiologists probably see more cases of this condition than they realize.

Evaluation starts with a full history and physical examination. Details such as recurrent carpal tunnel syndrome or  spinal stenosis with heart failure symptoms are good clues that amyloidosis may be present. The next step is to decide which tests to do to confirm the diagnosis. 

Although a number of options are available for testing, a strategy is required to avoid confusing or conflicting information. A testing and treatment strategy can also result in faster, safer, and more cost effective care. Our Center uses a 5-step management strategy (see diagram below) to systematically arrive at a diagnosis and offer the best treatment options. 

What treatment is available?  

The treatment of cardiac amyloidosis starts with treatment of heart failure symptoms. Care must be used because many of the medications used to treat regular heart failure may actually cause harm to someone with cardiac amyloidosis.

Patients with AL type cardiac amyloidosis are treated with chemotherapy directed at eradicating the abnormal bone marrow cells producing the large amounts of deposited light chain protein. We always collaborate with oncologists in the management of AL cardiac amyloidosis.

The treatment options for ATTR cardiac amyloidosis has greatly expanded with the availability of tafamidis, a newly FDA-approved drug that binds to the TTR protein and prevents it from destabilizing and unraveling.

In addition, some older medications may still have a useful role in well- selected patients, with close monitoring. Diflunisal is a non-steroidal anti-inflammatory drug (NSAID) that also binds to the same binding sites on the TTR protein as tafamidis does. Doxycycline, an antibiotic, disrupts fibril formation, especially when combined with the bile salt, tauroursodeoxycholic acid (TUDCA).

Epigallocatechin-gallate (EGCG) is nn interesting natural supplement found in green tea and has been shown to inhibit amyloid fibril formation. It holds some promise and is actively undergoing further research.

One other treatment option is liver transplantation which can be used in hereditary ATTR amyloidosis because the liver produces more than 95% of abnormal protein and as such,  replacing the liver stops the disease.

What about the risk to my family?    

ATTR cardiac amyloidosis can be either inherited or it can develop spontaneously. The symptoms and other manifestations of the two types can overlap considerably but only the hereditary type is passed on between family members.

Genetic testing is an important component of a comprehensive care program and allows us to confirm which type of ATTR is present and whether other family members are also at risk for developing the condition. Many genetic testing programs offer free or low cost testing for blood relatives once an initial  mutation is identified. Genetic counseling is also critical and helps put results into perspective for ease of mind.  

Patients with negative genetic testing have the wild type of ATTR and do not need to worry about their family members-this is a big relief and makes genetic testing worthwhile.