Lab Leaders Hopeful that New Test Will Catch Heart Attacks Earlier
Oct 23, 2019 08:00AM
● By MED Magazine
Regional Health Laboratories has introduced a new high-sensitivity cardiac troponin I test for patients who come to their hospitals and clinics with cardiac symptoms that could be early signs of a heart attack.
Like most US hospitals, Regional has used troponin I tests for some time. But the new, more sensitive test will allow doctors to better assess the damage done to the heart muscle and more quickly determine the best course of action.
“Troponin I is a protein in the heart muscle that helps your heart contract,” says Core Supervisor Jen Robinson, part of the team that helped bring the new test to Regional. “If you have an underlying heart problem, your troponin I level is elevated and we can see that in your blood.”
The problem is that even healthy hearts can produce some extra troponin I, such as after endurance exercise or with certain illnesses. Standard troponin I tests are not sensitive enough to distinguish between a “normal” elevated level and a level that indicates heart attack. This has been a special problem for women, whose smaller hearts naturally produce less troponin I.
“Previously, any number in a man or woman was considered positive,” says Robinson. “But now we have a reference range. And the ranges for women are much smaller than they are for men.”
Although the standard troponin I test has helped to improve the prognosis for men after heart attacks, the prognosis for women has remained steady. The more sensitive test could change that. In a European study, this new assay increased diagnoses of myocardial infarction in women by 11%.
The new test is also likely to speed up treatment time for all patients. Instead of having to wait three hours to have their second blood draw, they can be tested again in just one hour.
“We should be able to rule in or rule out heart attack sooner,” says Emily Leech, Director of Laboratory Services for Regional Health. “Either they will be able to go home from the ED sooner or we are going to be able to say ‘Yes, you are definitely having a heart attack’ sooner.”
The high-sensitivity test has become the new standard for diagnosing MI in Europe, where it has been in use since 2010. While the new test is not yet universally available in the US, and US studies are still limited, Leech and Robinson believe it represents the future of cardiac care.
“We would rather be on the front end of trying something new for our patients,” says Leech. “We are willing to say yes because this is best for our patients and the communities we serve.”
The new test has been in use at Regional Health since mid-October.