A new, highly sensitive blood test may help doctors quickly rule out heart attack for almost two-thirds of people who seek emergency room treatment for chest pain, a new study suggests.
Researchers said their findings could potentially reduce unnecessary hospital admissions and substantially lower health-care costs.
"Until now, there were no quick ways to rule out a heart attack within the emergency department," said the study's lead author, Dr. Anoop Shah, from the University of Edinburgh in Scotland.
"Over the last two decades, the number of hospital admissions due to chest pain has tripled. The overwhelming majority of these patients do not have a heart attack," Shah said.
Assessing a possible heart attack requires lengthy stays in the ER or hospitalization for repeat testing, the study authors pointed out.
The new test is more sensitive than the standard version, Shah's team said. It can detect far lower blood levels of troponin, a protein released when heart muscle is damaged. The more damage that occurs, the higher blood levels of troponin will be. A slight increase in troponin suggests some damage has occurred, while very high levels indicate a person has had a heart attack, the researchers explained.
Using this new test, doctors could potentially double the number of low-risk patients able to be safely discharged from the emergency room, the researchers reported in the Oct. 8 issue of The Lancet.
"Use of this approach is likely to have major benefits for both patients and health-care providers," Shah said in a journal news release.
For the study, the researchers measured troponin levels in more than 6,000 patients admitted to the hospital with chest pain, and assessed their risk for heart attack and death from heart attack within 30 days.
The investigators found that 61 percent of the patients with a troponin level below 5 ng/L (nanograms per liter of blood) were at very low risk of heart attack and could have been discharged early, regardless of age, gender, and risk factors for heart disease. One year out, these patients had a three times lower risk of heart attack and cardiac death than those with higher troponin levels, the researchers said.
The authors of an accompanying editorial in the journal said patient follow-up will be needed to validate use of this test in routine practice.
"Trials are needed to assess the safety and effectiveness of clinical pathways that involve no further testing for such patients," wrote Martin Than from Christchurch Hospital, New Zealand, and colleagues.
