A blood test designed to rapidly diagnose heart attacks has been verified in new trials. The research hopes to lead to a portable hand-held testing device that can not only speed up diagnoses in emergency rooms, but also be available in ambulances for on the spot analysis.

The test developed last year by a team at King's College London focuses on a protein called cardiac myosin-binding protein C (cMyC). The researchers found that levels of this protein rise quickly in a person's blood after a heart attack, making it a perfect biomarker to use in a small, portable device.

Millions of people present to hospital emergency rooms each year with symptoms of chest pain, but less than one third are ultimately found to have suffered a heart attack. Currently the process to diagnose a heart attack takes several hours involving an ECG and blood tests.

The current blood biomarker used to identify a heart attack is a protein called troponin. The problem with troponin is that it can often take several hours to accumulate in traceable levels in the blood, meaning patients often undergo at least two blood tests over a few hours to accurately identify a heart attack.

This new trial of the cMyC test examined 776 patients in Denmark, with blood samples taken as they were traveling to hospital by ambulance. The remarkable results found that in 95 percent of patients with subsequently verified heart attacks, the cMyC protein was seen in high enough concentrations to deliver an instant diagnosis. The traditional troponin test comparably was only able to diagnose 40 percent of patients at this early stage.

"It is important for both patients and doctors to work out early who has had a heart attack and who hasn't," says lead researcher on the project Tom Kaier. "Now that we know that this test is sensitive enough to give an almost immediate heart attack diagnosis, we need to work on developing a testing device. We'd love to see this used in A&E departments within the next 5 years."

If implemented into widespread use through a portable device the impact could be dramatic in freeing up valuable hospital space that is held by patients undergoing time-consuming testing. It also could help remotely diagnose patients in regional locations and avoid costly and unnecessary long trips to the hospital.