Patients with transthyretin amyloid cardiomyopathy (ATTR-CM) who received heart transplants had survival rates similar to those of individuals without ATTR-CM, according to a study published recently in Clinical Transplantation.
Post-transplant outcomes were previously thought to be worse among patients with ATTR-CM and other forms of cardiac amyloidosis, but recent evidence suggested that this may not be the case.
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 Organ Procurement and Transplantation Network updated its heart transplant allocation system in 2018 in an effort to address waitlist mortality and optimize patient prioritization.
Read more about ATTR-CM treatment and care
“Analysis of this impact highlights that patients with infiltrative cardiomyopathies now have a shorter waitlist time, decreased waitlist mortality, and increased rate of transplantation,” study authors said.
The authors found that after the new allocation system was implemented, the median time to heart transplantation was 45 days, compared to 174 days before the system was updated.
Heart transplant is not a first-line treatment for patients with ATTR-CM, but it may be considered in some individuals with severe heart failure.
The study included 28 patients with hereditary ATTR-CM, 17 patients with wild-type ATTR-CM, eight patients with light chain amyloidosis, and two patients with hereditary apolipoprotein A1 amyloidosis. All participants received a heart transplant between January 2007 and December 2020.
After heart transplantation, the one-year survival rate among patients with ATTR-CM was 96%; the three-year survival rate was 91%; the five-year survival rate was 84%; and the 10-year survival rate was 64%. Additionally, there was no difference in overall survival among patients with cardiac amyloidosis compared to those without (P = 0.816).
During the follow-up period, 16 deaths were recorded. Among these, five were directly attributed to cardiac amyloidosis, including death in three individuals with light chain amyloidosis and two individuals with ATTR-CM.
Seven deaths occurred on the waitlist before the new allocation system was implemented; no deaths were recorded after the change was made.
Analysis of multi-organ transplant outcomes revealed that as novel therapies have emerged, the frequency of multi-organ transplant has declined. Of the four patients with hereditary amyloidosis who received a transplant between 2019 and 2020, one received a combined heart and liver transplant, and the remaining three received only heart transplants.
“Further studies are needed for ideal patient selection, post-[heart transplant] surveillance and the optimal utilization and timing of therapies post-transplant,” the study concluded.
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