Now, `sensitive` blood test that can rule out heart attacks

London: A team of researchers has come up with a new heart attack test that can identify two-thirds of patients at very low risk of heart attack in the emergency department.

Using a high sensitivity blood test, researchers have identified the optimal level of a protein called troponin that could rule out a diagnosis of heart attack for two-thirds of people attending the emergency department, according to new research.

Using this threshold in routine practice could potentially double the number of patients suitable for immediate discharge directly from the emergency department, say the authors.

Until now, there were no quick ways to rule out a heart attack within the emergency department, explains lead author Anoop Shah from the University of Edinburgh in the UK, adding that they have identified a cardiac troponin concentration (less than 5 nanograms per deciliter) below which patients are at very low risk of heart attack either during the admission or in the ensuing 30 days.

He added that these patients are therefore potentially suitable for immediate and safe discharge from the emergency department. These findings could dramatically reduce unnecessary hospital admissions and provide substantial cost savings for healthcare providers.

The test used in this study is more sensitive than the standard version and can detect far lower levels of troponin in the blood. Using this test, troponin levels were measured in over 6000 patients with chest pain admitted to four hospitals in Scotland and the USA.

Shah and colleagues prospectively evaluated the negative predictive value (the probability that patients were not at risk) of heart attack or subsequent death from a heart condition after 30 days for a range of troponin concentrations.

According to Shah, 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.

This study shows that low plasma cardiac troponin concentrations at presentation identify up to two-thirds of patients who are at very low risk of heart attack and could be safely discharged from the Emergency Department. Use of this approach is likely to have major benefits for both patients and healthcare providers.

The study is published in The Lancet.