Blood Test May Detect Heart Damage Years Before Symptoms Appear
Test May Soon Help Doctors Spot Early Heart Failure
But other experts caution that more research is needed before the test becomes widely used, largely because there’s very little information to help doctors and patients know what to do with their results.
“We don’t know, for example, if a patient at higher risk for heart failure as identified by troponin testing may benefit from additional medications or a certain kind of clinical workup,” says Willibald Hochholzer, MD, of Brigham and Women’s Hospital in Boston, who was not involved in the study. “There is still much to be learned.”
Many Middle-aged Adults Test Positive for a Marker of Heart Damage
For the first study, researchers performed so-called highly sensitive troponin T tests on blood samples taken from some 3,500 people between the ages of 30 and 65 who were enrolled in the Dallas Heart Study. Participants were then followed for an average of about six-and-a-half years. During that time there were 151 deaths, and 62 of those were caused by heart disease.
When researchers analyzed the results, they found that 25% of participants had detectable troponin T levels at the beginning of the study.
Perhaps more surprising, however, was that when they narrowed their results to people without medical conditions known to contribute to heart disease, like diabetes, high blood pressure, or chronic kidney disease, 1 in 6 still had detectable levels of the protein.
And the higher a person’s level, the greater their risk of dying, even if they had no other known risk factors. About 2% of the group with the lowest troponin T levels died during the study compared to 28% of the group with the highest levels.
But de Lemos says troponin testing is likely to complement, rather than replace, other kinds of heart checks because the protein seems to be picking up a “different family of risk.”
“This looks like not a marker of heart attacks in the sense of myocardial infarction, which is a problem of atherosclerosis or thrombosis, but rather a marker of heart failure, which is typically problems with either weakening or thickening of the heart,” he says.
“These are changes in the heart muscle before people develop frank heart failure. It’s reading early heart damage caused not by heart attacks but by chronic stress on the heart, be it from hypertension or kidney disease, or other factors,” de Lemos adds.