Saliva test may speed heart attack diagnosis

NEW YORK (Reuters Health) - A simple saliva test may one day be used in ambulances, restaurants, neighborhood drug stores, or other places in the community to quickly tell if a person is having a heart attack.

"Proteins found in the saliva have the ability to rapidly classify potential heart attacks," Dr. John T. McDevitt, a biochemist at the University of Texas at Austin, told Reuters Health.

McDevitt and colleagues developed a nano-bio-chip sensor that is biochemically programmed to detect sets of proteins in saliva capable of determining whether or not a person is currently having a heart attack or is at high risk of having a heart attack in the near future.

With the saliva heart attack diagnostic test, a person spits into a tube and the saliva is then transferred to credit card-sized lab card that holds the nano-bio-chip containing a standard battery of cardiac biomarkers. The loaded card is inserted like an ATM card into an analyzer that determines the patient's heart status in as little as 15 minutes.

In a study involving 56 people who had a heart attack and 59 healthy "controls" who did not, "we found that our test could distinguish between heart attack patients and controls with about the same diagnostic accuracy" as that of standard blood tests, McDevitt noted in an interview with Reuters Health.

Many heart attack patients, especially women, experience nonspecific symptoms, or have normal EKG readings, making timely diagnosis difficult, McDevitt explained.

"In our small trial, we had about one third of the patients with these...silent heart attacks on EKG." These patients need to go the emergency department and have their blood drawn and tested for enzymes that are indicative of a heart attack, "which could take an hour to an hour and a half."

The saliva test could be used in conjunction with the EKG and "aid in rapidly diagnosing heart attacks that are silent on EKG," McDevitt said, adding that larger and more refined studies are planned.