As a rare, progressive disease of the heart muscle, transthyretin amyloid cardiomyopathy (ATTR-CM) damages the heart and eventually leads to heart failure. As amyloid deposits build up in the heart, people living with ATTR-CM experience symptoms similar to progressive congestive heart failure. Delayed diagnosis and treatment is related to poor outcomes.
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.
How does ATTR-CM affect the heart?
When the transthyretin (TTR) protein becomes unstable, it misfolds and forms clumps of insoluble fibers called amyloids that are then deposited in the body’s organs, including the heart.
When they accumulate in the heart, the left ventricle—or the heart’s main pumping chamber—becomes damaged. The cardiac muscle, also known as the myocardium, thickens and loses its elasticity. As it stiffens, it makes it harder for the left ventricle to relax and fill with blood. This puts a strain on the heart as it works harder to pump blood to the body, eventually leading to heart failure.
In heart failure, the heart is unable to supply the body with enough oxygen-rich blood. This leads to fatigue, swelling of feet and ankles, shortness of breath, and coughing or wheezing. Without medication and lifestyle changes, heart failure is life-threatening. ATTR-CM is also a progressive disease, meaning the heart continues to deteriorate as a result of the amyloid deposits.
In addition to heart failure symptoms, people living with ATTR-CM can also experience brain fog, bloating of the stomach and cardiac arrhythmias, including an irregular heart rate, palpitations or atrial fibrillation in which the heartbeat is rapid and irregular.
Supporting heart health in ATTR-CM
Regular cardiac monitoring via imaging tests such as echocardiograms, ultrasounds and cardiac magnetic resonance imaging will assess the function and structure of the heart, disease progression and the effectiveness of treatment.
A treatment plan for managing your symptoms and slowing disease progression will include ATTR-CM medication that either slows or stops the amyloid deposits in your heart. Your health care team may also prescribe medication to alleviate the symptoms of heart failure.
Making permanent changes to your lifestyle and adopting a healthy diet will support the health of your heart. Regular exercise, low-salt intake and maintaining an optimal weight will reduce the strain on your heart.
In advanced heart failure, a heart transplant may be considered. As the liver produces the TTR protein, liver transplantation might also be an option. New treatments are currently in clinical development, and future therapies could soon be available.