Nanochip Diagnoses Heart Attack Using Saliva

A new nano-biochip tht can analyze a few drops of saliva could possibly help give early diagnosis of a heart attack, report researchers at the University of Texas at Austin.

The device, the size of a credit card, can produce results in as little as 15 minutes. It could someday be used to assay a patient’s saliva on board an ambulance, the doctors office or even the local drugstore, helping prevent unnecessary damage from cardiac disease.

“Many heart attack victims, especially women, experience nonspecific symptoms and secure medical help too late after permanent damage to the cardiac tissue has occurred,” according to Dr. John T. McDevitt, designer of the nano-bio-chip. “Our tests promise to dramatically improve the accuracy and speed of cardiac diagnosis.”

McDevitt and his team benefited from the recent identification of various blood serum proteins that are indicators of cardiac disease. For example, a protein that promotes inflammation and immune responses known as Chlamydia pneumonia heat shock protein 60 (Cp-HSP60) appears to be a strong indicator of heart disease, according to a 2003 study. (A Bacterial Inflammatory Protein Linked With Heart Disease Risk, Circulation: Journal of the American Heart Association, 2003, June 11) Ninety-nine percent of patients with acute coronary syndrome tested positive for Cp-HSP60 in their blood according to the lead author.

Using microelectronics components and microfabrication developed originally for the electronic industry, they developed a series of compact nano-bio-chip sensor devices that are biochemically programmed to detect sets of these proteins in saliva. The new technology is still in the clinical testing phase, but it is a strong candidate for further commercial development.

How the Test Works

A patient spits into a tube and the saliva is then transferred to a credit card-sized lab card that holds the nano-bio-chip. The loaded card is inserted like an ATM card into an analyzer that manipulates the sample and analyses the patients cardiac status on the spot.

“What is novel here is our ability to measure all such proteins in one setting and to use a noninvasive saliva sample, where low protein levels make such tests difficult even with large and expensive lab instruments,”McDevitt says.

In 2008, an estimated 770,000 Americans will have a new coronary attack, and about 430,000 will have a recurrent attack.

Test Results Promising

University of Kentucky College of Dentistry researchers tested saliva from 56 people who had a heart attack and 59 healthy subjects for 32 proteins associated with atherosclerosis, thrombosis and acute coronary syndrome.

They found these proteins were in higher concentrations in saliva of heart attack victims, and that specific salivary proteins were as accurate in the diagnosis of heart attack as those found in blood serum using current testing methods. The test can reveal that a patient is currently having a heart attack necessitating quick treatment. It can also tell a patient that they are at high risk of having a future heart attack.