Advanced blood tests to diagnose heart attacks

Every year in the UK, up to a million people attend A&E with chest pain, but not all of these people will be having a heart attack. An important part of getting the right care to the right people is being able to quickly and accurately diagnose whether someone is having a heart attack and reassure and send home people who haven’t.

One of the first tests doctors use is to measure the amount of a protein called troponin in the blood. Troponin is released from heart muscle when it is damaged, so an increase can suggest that someone is having a heart attack. Tests to detect troponin have got increasingly more sensitive – so they are able to detect ever smaller amounts of troponin in the blood. But slight increases in troponin levels may not always indicate a heart attack.

Ruling out heart attack

Until recently, we didn’t know if using high-sensitivity troponin tests actually saved more lives. Did these tests help doctors diagnose and treat heart attacks that would previously have gone undiagnosed? Or by contrast, was the high-sensitivity test giving too many false-positive results – suggesting that patients had had a heart attack when they hadn’t – potentially leading to unnecessary or harmful treatment?

These questions were addressed by the BHF-funded High-STEACS trial, which was led by Professor Nick Mills (BHF Senior Fellow) and colleagues at the University of Edinburgh. Their results, announced in 2015, showed that although using high-sensitivity troponin tests did not identify more people who had suffered a heart attack, these tests were very helpful in ruling out a heart attack more confidently. That’s important because it means that patients can be reassured and go home sooner rather than waiting around for more tests, helping to free up hospital beds for other patients and saving hospitals money.

First published 1st June 2021