Patients with asymptomatic transthyretin amyloid cardiomyopathy (ATTR_CM) and high cardiac uptake appear to have an increased risk of cardiovascular death and could benefit from disease-modifying treatment, according to a study recently published in JAMA Cardiology.
“Our findings call into question the current recommendations about whether asymptomatic patients with Grade 2 or 3 myocardial uptakes should also be treated with disease-modifying drugs,” the authors said.
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.
The authors aimed to analyze the natural history of patients with asymptomatic ATTR-CM through a retrospective multicenter cohort study including nearly 500 patients with asymptomatic ATTR-CM.
Read more about ATTR-CM therapies
All included patients underwent cardiac bone scintigraphy to determine their cardiac uptake grade. The authors analyzed hospital data to assess each patient’s cardiovascular mortality and unplanned hospitalizations and their correlation with cardiac uptake.
Over 75% of patients had Grade 2 or 3 cardiac uptake. About 26% had evidence of cardiac amyloid infiltration in 2008. The proportion rose to 49% in the 2020-’23 period.
Researchers observed that patients with Grade 1 cardiac uptake had better survival, lower cardiac biomarkers and less frequent arrhythmias. Patients with Grade 2 or 3 uptakes had more pronounced disease progression as evidenced by a higher rate of hospitalization or diuretic initiation.
There is currently scarce data on the natural history of patients with asymptomatic ATTR-CM, and clinical trials investigating the benefits of disease-modifying agents for ATTR-CM included only symptomatic patients. There is currently not enough evidence to affirm that patients with asymptomatic ATTR-CM can benefit from drugs such as tafamidis.
The increased risk of cardiovascular mortality in patients with asymptomatic cardiac uptake highlighted the need for clinical trials investigating the benefits of tafamidis and similar drugs to this population.
“These findings support the use of disease-modifying treatments in patients with ATTR cardiac amyloid infiltration with Grade 2 and 3 uptake and highlight the need for large-scale studies to assess their role in Grade 1 uptake,” the authors said.
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