A recent multi-center study led by doctors at Boston Medical Center and Columbia University found that having a genetic variant within the prealbumin gene alone is just not sufficient for diagnosis of transthyretin amyloid cardiomyopathy in older Black patients. Published within the Journal of the American Heart Association, researchers discovered that a blood test that measures the transthyretin or prealbumin protein may additionally be helpful in diagnosing transthyretin amyloid cardiomyopathy and could possibly be used to trigger more definitive imaging testing.
Transthyretin amyloid cardiomyopathy (ATTR‐CM) is an underdiagnosed reason behind congestive heart failure amongst patients 60+ years of age. There may be a typical genetic variant, V122I (or Val122Ile), in a protein called transthyretin (TTR) or prealbumin that’s related to ATTR-CM and present in 3.4% of Black individuals, or 1.5 million people. V122I is so common because when present, the variant is passed genetically from parent to child 50% of the time. Importantly, of those that have this variant, it’s unknown who will develop ATTR.
Researchers note that since more individuals are getting their genes tested using business services, a few of which return the V122I test result, it is vital for people to know the association between a positive genetic result and the disease with which it’s associated.
“Cardiac amyloidosis is a serious heart condition that will be attributable to a typical genetic variant carried by 1.5 million people,” said senior creator Frederick L. Ruberg, MD, a cardiologist at Boston Medical Center and Associate Professor of Cardiovascular Medicine and Radiology at Boston University Chobanian & Avedisian School of Medicine. “Our study shows that of those that have inherited this variant, only 39% developed cardiac amyloidosis, so not everyone who inherits the variant will necessarily develop this serious condition.”
Researchers enrolled 278 self-identified Black heart failure patients from the Screening for Cardiac Amyloidosis with Nuclear Imaging in Minority Populations (SCAN-MP) study, funded by the National Institutes of Health. Study participants live in Boston and Latest York City and were tested for the genetic variant. Participants were also scanned with a special nuclear heart-imaging test to find out whether or not they have ATTR-CM.
With 1.5 million people carrying the V122I variant within the US, there are an incredible number people in danger for ATTR-CM. This study shows that though carriers can have the gene, they’ll not necessarily develop the disease. The study also shows that just testing for and identifying the V122I variant is just not enough to infer that that heart failure is as a result of cardiac amyloidosis.
“Our study suggests that a widely available blood test to measure prealbumin levels may be useful in identifying patients that ought to have more sensitive imaging testing for ATTR-CM,” said co-senior creator Mathew Maurer, MD, Arnold and Arlene Goldstein Professor of Cardiology at Columbia University Irving Medical Center and Director of the Cardiac Amyloidosis Program. “Our results also help higher understand how heart failure from ATTR-CM impacts older Black individuals.”
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Journal reference:
https://doi.org/10.1161/JAHA.122.028973