A new blood test might help doctors figure out faster whether someone’s having a heart attack.
The test reliably told doctors which patients were not having heart attacks after only one blood sample, compared to the current method that requires several hours and multiple blood samples, researchers found.
“The ultimate goal would be to have a single blood draw for the majority of patients,” said study author Dr. Atul Anand, of the University of Edinburgh in Scotland.
The test could move about two-thirds of the people with chest pain through the ER faster and ultimately save time and resources, he said.
The new test is similar to its predecessors, but it’s more sensitive to proteins known as troponins, which are released into the blood when the heart is damaged.
Traditionally, doctors run several troponin tests over six to 24 hours. If levels are still considered normal after about 12 hours, a heart attack is unlikely.
The new findings come from a two-part study reported in The Lancet.
First, in 4,870 people who came to emergency rooms in Scotland in 2013 and 2014 with symptoms of a possible heart attack, the researchers used a high-sensitivity troponin test manufactured by Abbott Laboratories.
They evaluated the data from those patients to determine what low level of troponin in the blood would reliably indicate that a person is not having a heart attack.
Ultimately, 3,799 of those people turned out not to be having heart attacks. In those individuals, 61 percent had a troponin level below 5 nanograms per liter (ng/L).
Below that 5 ng/L cutoff, the researchers calculated, there’s 99.6 percent certainty that people will not go on to have with a heart attack within the next 30 days.
Next, the researchers replicated their results in another 1,126 patients in Scotland and 308 patients in the U.S.
What the new study shows is that people who test below the 5 ng/L threshold are not in immediate danger, Anand said. They may be able to go home or be referred to their primary care doctor.
“The findings are pretty interesting and compelling,” said Dr. Sripal Bangalore, a cardiologist at NYU Langone Medical Center in New York City.
However, the test is not perfect and some people who are having heart attacks will be missed, said Bangalore, who wasn’t involved in the new study.
“There is a chance, but it’s going to be an extremely small group of patients,” he said. “But even if (the test is) accurate you have to do it in conjunction with additional follow-up.”
Anand agreed, pointing out that the test isn’t done in isolation. Patients will also get electrocardiograms and evaluations by doctors and nurses.
“When it comes to individual patients, the doctor will be the best person to consider this negative test along with everything else,” Bangalore told Reuters Health.
Anand also cautioned that the test was slightly less reliable when it was done within two hours of the start of symptoms.
The researchers will continue to evaluate the test in a real-world setting, Anand said.
The test costs about $8, and Anand’s team is in the process of completing a cost-benefit analysis.
Presently, the new test is available in Europe but not in the U.S.
Source: Reuters Health