The heart inflammation known as myocarditis can have unpredictable outcomes. Typically occurring in young adults after a viral illness, myocarditis can appear with symptoms such as shortness of breath, fatigue and dizziness. The condition may resolve without long term consequences, but is a leading cause of heart failure and sudden death. To date, doctors have not had biomarkers or other tests to indicate who’s most at risk of dying. But a research team at Mayo Clinic’s campus in Florida has identified a new tool to test patients with myocarditis and determine if they’re at risk of heart failure.
In the Journal of the American Heart Association, the team found that elevated levels of a protein in the blood, soluble ST2, are a predictor of heart failure in men under 50 years old with myocarditis.
“Our study found that sST2 is a biomarker that can be added to current tests for myocarditis to determine if these patients are in need of life-saving therapies,” says the study’s co-lead author Katelyn A. Bruno, Ph.D.
An sST2 biomarker test has already been FDA-approved and is used to gauge other heart conditions, such as heart attack and chronic heart failure, but this finding is the first applied to myocarditis. In animal models of the disease, the team of researchers found that ST2 is the key genetic pathway that leads to heart failure during myocarditis. But the findings also presented a significant twist: researchers found the biomarker is only elevated in men with myocarditis under 50 and predictive of death in this particular group.
Even though both men and women with myocarditis had elevated sST2, the biomarker was not predictive of myocarditis-related heart failure for men over age 50, or women. However, because it’s a protein that rises when inflammation occurs, its levels may indicate whether all patients, male or female, are at risk of heart failure from less common variants of myocarditis. Significantly, the study found sST2 levels varied between healthy men and women, even at low levels that aren’t indicative of heart failure.
“The body’s sex hormones may alter the presence and the effect of the protein,” says co-principal investigator DeLisa Fairweather, Ph.D., in the Department of Cardiovascular Medicine. “Those hormones change throughout life, so the levels and contribution of sST2 may change, as well.”
Dr. Fairweather notes more research is needed to know if women with myocarditis are at increased risk of heart failure after menopause.
“This is a biomarker that can impact the clinical care of patients with myocarditis,” says Dr. Fairweather. “The study suggests that more research is needed to understand how sST2 levels differ between men and women for other cardiovascular diseases. Moreover, the findings indicate how important it is to analyze all biomedical research results according to sex and age.”
The study was funded by the National Institutes of Health and the American Heart Association. In addition to Drs. Fairweather and Bruno, other Mayo Clinic authors include: Lori Blauwet, M.D., Erika Douglass, MPH, Anneliese Hill, and Leslie Cooper, M.D.