Around 1 million people a year in the U.K. are admitted to hospital with chest pains suffering a suspected heart attack, but as many as 80% of these people will then be discharged after a lengthy and often anxious stay. A more sensitive blood test could more than halve the number of people who are required to stay in hospital for further tests, which would reduce stress for patients, ease hospital wards, and save money.
Currently, when someone may have suffered a heart attack – presenting a “heavy” chest, pain in the arms and stomach, and light-headedness, among other symptoms – they are then subjected to a long testing procedure. This involves a blood test that looks for a particular set of proteins produced by damaged heart tissue, called troponins, first when the patient arrives, and then sometimes up to six hours later. During this time, that person is both worrying about the results, and also taking up a hospital bed which could be used for someone else should they not need to be there.
The newly developed test builds on the old one, but greatly increases its sensitivity in being able to detect much lower levels of troponin in the blood. The results are available within half an hour, with 99.6% accuracy, meaning that doctors will be able to confidently rule out a heart attack without compromising patient safety.
“Until now there were no quick ways to rule out a heart attack within the emergency department,” explained Dr Anoop Shah, who led the study published in The Lancet, in a statement. “We have identified a cardiac troponin concentration below which patients are at very low risk of heart attack either during the admission or in the ensuing 30 days. These patients are therefore potentially suitable for immediate and safe discharge from the emergency department.”
The new study measured the troponin levels in more than 6,000 people who showed the symptoms of a heart attack when admitted to four hospitals in both Scotland and the U.S. They found that troponin levels below a particular threshold identified 61% of patients with a very low risk of heart attack, and who were probably eligible for early release from hospital. This was true regardless of the patient’s age, sex or prior heart conditions.
The newly refined test is estimated to cost around $15 (£10), although not all hospitals have the facilities to conduct the more sensitive analysis. Last year, the test was given the go-ahead by the National Institute for Health and Care Excellence, which sets the clinical and safety guidelines used in the U.K., but it is unsure when it will be rolled out across the country.