Spit in a test tube may one day diagnose heart attacks in minutes

26 Aug 2020

Image: © karenfoleyphoto/Stock.adobe.com

Results from early research has found it may be possible to diagnose a heart attack in minutes through a saliva sample.

A rapid-response heart attack test could be on the cards in years to come following a breakthrough by a research team at the Soroka University Medical Centre in Beer Sheva, Israel. Unlike a standard blood test that could tell a doctor within an hour whether someone has had a heart attack, this latest saliva-based test can provide results in 10 minutes.

Set to present the findings to the European Society of Cardiology at its annual congress, the team said all the patient would need to do is spit into a test tube and the results could quickly produce a diagnosis.

Heart attacks need urgent diagnosis, followed by treatment to restore blood flow to blocked arteries. Diagnosis is based on symptoms such as chest pain, an electrocardiogram and a blood test for cardiac troponin, a protein released into the blood when the heart muscle is injured.

The team wanted to see whether cardiac troponin could be detected in the saliva of patients with heart muscle injury. In a preliminary study, it took saliva samples from 32 patients with heart muscle injury and 13 healthy volunteers.

Half of each sample then underwent a unique processing procedure to remove highly abundant proteins, and the other half was left in its natural state.

Further research needed

After testing both sets of samples, the team found similar cardiac troponin levels in the processed saliva to blood sample tests. Around 84pc of the processed saliva samples tested positive for troponin, compared to just 6pc of the unprocessed saliva. Among the healthy participants, no cardiac troponin was detected in either the processed or unprocessed samples.

“This early work shows the presence of cardiac troponin in the saliva of patients with myocardial injury,” said the study’s author, Dr Roi Westreich.

“Further research is needed to determine how long troponin stays in the saliva after a heart attack. In addition, we need to know how many patients would erroneously be diagnosed with heart attack and how many cases would be missed.”

This further research will include a larger number of patients and the creation of a prototype cardiac troponin test using saliva.

“This prototype will be tailor-made for processed saliva and is expected to be more accurate than using a blood test on saliva,” Westreich said. “It will be calibrated to show positive results when saliva troponin levels are higher than a certain threshold and show a yes/no result like a pregnancy test.”

Colm Gorey was a senior journalist with Silicon Republic