What’s The Standard of Care For Treating ATTR-CM?

Transthyretin amyloid cardiomyopathy (ATTR-CM) is a rare condition that affects the heart’s pumping ability. For many years, there was no standard treatment for ATTR-CM, a disease in which in which transthyretin proteins become malformed and convert into amyloid fibrils, settling in the wall of the left ventricle.

The thicker ventricular wall makes it harder for the left ventricle to relax sufficiently to fill with the blood and contract vigorously enough to pump blood to meet the body’s needs.

Unable to treat ATTR-CM directly, doctors focused on managing symptoms, which are very much like those associated with heart failure. These include:

• Arrhythmia (heart rhythm disturbance)
• Decreased exercise tolerance
• Lightheadedness
• Shortness of breath

“ATTR cardiomyopathy is an evolving condition, and until a few years ago, we did not really have anything to treat the disease in and of itself,” says Dr. Aeshita Dwivedi, a cardiologist at Lenox Hill Hospital in New York. “All we could do was really treat the symptoms of heart failure. More recently, we have been fortunate to have newer drugs that can impact the disease process.”

Tafamidis Offers Hope For ATTR-CM

In 2019, the FDA approved tafamidis (Vyndamax), a once-daily oral medication that blocks the breaking up of transthyretin proteins and the subsequent formation of amyloid fibrils. However, the drug costs more than $200,000 annually, though most insurance providers should cover it or a large portion of it. There is currently no generic version.

Another form for tafamidis, called Vyndaqel, is also a once-per-day regimen, but each dose includes four pills. The two forms of tafamidis treat both kinds of ATTR-CM: the hereditary type caused by a mutation of a transthyretin gene and the wild type, which has no genetic component and is triggered by unknown causes.

Tafamidis doesn’t cure the disease or reverse its course. But the drug can slow its progress by interfering with the breakdown of transthyretin proteins and the subsequent formation of amyloid fibrils. “What Vyndamax does is stabilize this abnormal, misfolded protein so that more of doesn’t get deposited in your heart,” Dr. Dwivedi says, adding that other medications are in the works that may help stop production of abnormal forms of transthyretin in the liver.

A 2018 study of tafamidis suggests that the drug helped reduce the risk of death by 30 percent over the 30-month study period and cut the risk of hospital admission by nearly one-third. The study also found that tafamidis helped slow the decline in everyday functioning associated with ATTR-CM.

And a 2021 study suggests that a timely diagnosis and treatment with tafamidis could extend life expectancy by 5.46 years for people with wild-type (non-hereditary) ATTR-CM and by 7.76 for individuals the hereditary form of ATTR-CM.

Treating Heart Failure Symptoms

While newer drugs are helping to target the causes of ATTR-CM, treatment for this condition still requires medications, devices and procedures to manage the complications of a weaker heart.

New York cardiologist Dr. Philip Weintraub explains that treatment decisions usually follow the identification of symptoms and their causes. “It invariably depends on the symptoms that if one has shortness of breath, for example, one has to ask themselves why is there a shortness of breath?” he says. “And if I were to use a diuretic, an agent that would decrease the free water that is in the body, would I allow that individual to empty the lung that is congested and improve the quality of their life. One also has to ask themselves as to what other conditions can be provoked.”

Other medications that may be necessary to treat the heart failure symptoms associated with ATTR-CM include:

• Anticoagulants (blood thinners) to reduce the risk of blood clots, especially if atrial fibrillation or other arrhythmia is present
• Antihypertensives to lower blood pressure
• Cholesterol-lowering medications, such as statins
• Digoxin, to treat an irregular heartbeat

Dr. Weintraub also notes that ATTR-CM is associated with sudden cardiac arrest—the unpredictable and immediate halt to heart function and breathing. As a result, standard care for ATTR-CM can often require the use of an implantable cardioverter defibrillator (ICD), a small battery-powered device placed in the chest to shock the heart if signs of sudden cardiac arrest emerge.

Another treatment, called cardiac resynchronization therapy (CRT), uses a special implanted pacemaker to help coordinate the beating of both sides of the heart to help ensure the pumping function is as strong and effective as possible.

One other implantable device, a left ventricular assist device (LVAD) may eventually be necessary if the heart reaches a point where medications and lifestyle changes are no longer enough to accommodate a weaker heart. An LVAD is a mechanical pump that maintains the heart’s pumping ability. LVADs used to be primarily considered bridge therapies for individuals awaiting a heart transplant. But in recent years, LVAD technology has improved significantly and research suggests that these devices should be considered for long-term use. A 2018 review of LVAD studies notes that the survival times are improving for individuals who receive LVADs but are no longer good candidates for a heart transplant. The researchers also predict that LVADs will soon be considered viable alternatives to much more invasive and higher-risk heart transplants.

Of course, medications and devices can be more effective if you help them along with a heart-healthy lifestyle. Some important changes you may need to make with ATTR-CM include:

• Eating a heart-healthy diet, such as the Mediterranean-style diet
• Limiting or avoiding alcohol
• Maintaining a healthy weight
• Monitoring your blood pressure
• No smoking
• Sleeping at least seven hours a night or napping to make up for interrupted nighttime sleep
• Supervised exercise
• Tracking your fluid intake because heart failure often means fluid retention

Questions To Ask Your Doctor

• Are there payment assistance programs that can help pay for tafamidis?
• Will my insurance cover tafamidis?
• Are there side effects associated with treatment?
• What lifestyle changes should I make as a result of ATTR-CM?
• Do I need more than oral medications to treat ATTR-CM?

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