Genetic testing in patients with early-onset atrial fibrillation (AFib or AF) can identify variants associated with more serious cardiomyopathy and arrhythmia syndromes that may otherwise remain undiagnosed, according to a Vanderbilt-led study recently published in JAMA Cardiology.
The prospective, observational cohort study included 1,293 participants who had diagnosed heart failure before age 66 and received genetic testing.
The younger the patient, the more likely genetic testing detected disease-associated rare variants in cardiomyopathy or arrhythmia genes. For example, 16.8% of patients diagnosed with AF by 30 years of age were able to identify a disease-associated variant with genetic testing.
The results suggest that genetic testing is useful for younger patients with AF, said Zachary Yoneda, MD, MSCI, a fellow in the Division of Cardiovascular Medicine and an author of the study. Testing can serve as a kind of early warning system for more serious conditions that may exist in such patients.
“I think the big take home point for this paper is mostly recognition. If you see a patient who has atrial fibrillation at a young age, you shouldn’t let that go without explaining it,” Yoneda said.
“It really is a shift in how people think about atrial fibrillation. It really is a very different disease in somebody who is 70 and has a lot of heart problems than in somebody who’s young and doesn’t.”
Yoneda said he and his mentor, Ben Shoemaker, MD, MSCI, assistant professor of Medicine, decided to study the topic to explain why younger patients present with atrial fibrillation, which is unusual.
“There’s increasing interest among clinicians for genetic testing when AF is diagnosed in relatively young patients that is not fully explained by clinical risk factors,” Shoemaker said. “A reason for this is research over the past several years has raised the concern that AF may be an early sign of more serious inherited cardiomyopathy or arrhythmia syndromes. We conducted this study to inform clinicians about the yield of genetic testing among different age groups and to identify the most common genes that harbor disease-associated variants.”
Yoneda said future study could determine whether doctors can prevent long-term heart failure in early-onset AF patients by identifying their conditions through genetic testing, then intervening to treat them before their conditions worsen.
“We will need to do some more research to determine if we can impact the disease course,” he said. “Maybe, if you catch these people, because of their genetics, at age 30 and you start them on treatment, their heart never gets bad.”
