A research team led by Scott Solomon, MD, of the BWH Cardiovascular Division, reports in The New England Journal of Medicine that a known genetic variant associated with a severe type of heart disease and found in almost four percent of black Americans does not appear to increase the risk of mortality but is tied to increased risk of heart failure.
Nearly 4 percent of black Americans, representing 1.5 million individuals in the U.S., carry a genetic variant in the transthyretin protein that increases their risk for developing a specific type of heart disease called late-onset restrictive amyloid cardiomyopathy. When patients present with this disorder, it is often late in the course of their disease, and they are generally suffering manifestations of severe heart failure. Exactly how many patients who have this genetic variant will go on to develop amyloid cardiomyopathy and suffer overt heart failure has not been known, but has been assumed to high.
Researchers at Brigham and Women’s Hospital in collaboration with the National Institutes of Health Atherosclerosis Risk in Communities study and the Human Genetics Center at Baylor College of Medicine have utilized data from a large NIH cohort of black patients who have been followed since 1985 to determine the effect of this variant on overall survival, likelihood of developing heart failure and the incidence of typical amyloid heart disease. They found that while the overall incidence of overt cardiac amyloidosis was low (about 6 percent) and overall survival was similar in those with and without the variant, individuals with the genetic variant were about 50 percent more likely to develop heart failure, despite the absence of typical features of cardiac amyloidosis.
“Our data suggest that while the majority of individuals with this genetic variant will not develop overt disease, a proportion may be at increased risk for developing heart failure,” said Solomon. “As new therapies for amyloidosis are currently being developed and tested, there may be a role for genetic screening in black Americans at risk for this disorder and more definitive cardiac screening in those who carry the genetic variant.”