A new study published in The European Journal of Internal Medicine reveals that elevated levels of a liver enzyme called gamma-glutamyl transferase (GGT) may help predict severity and outcomes in people with transthyretin amyloid cardiomyopathy (ATTR-CM).
ATTR-CM, which is a leading cause of heart failure in older adults, occurs when misfolded transthyretin protein builds up in the heart. Although this protein is produced in the liver, liver disease has not typically been associated with ATTR-CM.
For the study, the researchers sought to explore whether there may be any liver involvement in the disease in a large, real-world cohort of patients. They analyzed health records, including imaging results, blood tests and liver function tests, from 528 people with ATTR-CM across four Italian hospitals.
Learn more about ATTR-CM prognosis and staging
The results found that while no patients showed liver abnormalities on bone scintigraphy, nearly half had elevated levels of GGT. Other liver enzymes, including AST, ALT and alkaline phosphatase, were much less frequently elevated.
Specifically, people with GGT levels of 82 U/L or higher were more likely to have worse heart function, signs of venous congestion and impaired kidney function. During a median follow-up of 2.6 years, 39% of the study population died and 33% were hospitalized for heart failure. Elevated GGT was a strong predictor of both outcomes.
The researchers suggest that higher levels of GGT may reflect a combination of liver congestion due to heart failure, possible liver infiltration by amyloid protein and systemic oxidative stress.
The study has several limitations, including the lack of data on alcohol intake, which can impact the liver, and limitations of the liver testing used. Still, the researchers say that the findings suggest GGT measurement may be useful in the future to help assess risks in people with ATTR-CM.
“Monitoring GGT may provide a valuable and accessible tool for identifying high-risk patients and guiding management in [ATTR-CM],” they concluded.
The authors call for further studies to confirm their findings and better understand the role of liver involvement in ATTR-CM.
Sign up here to get the latest news, perspectives, and information about ATTR-CM sent directly to your inbox. Registration is free and only takes a minute.
