Peng Zheng shows off the team's chip, the heart of the newly developed blood test that can identify the earliest signs of heart attacks in minutes, not hours. Credit: Will Kirk/Johns Hopkins University
An estimated 800,000-plus people have heart attacks every year just in the United States. But even with a sample that large, heart attacks can be difficult to diagnose—mostly because the symptoms can vary so widely. They’re also different based on sex. For example, both men and women get chest pains, but women may also experience nausea, dizziness, tiredness and cold sweats.
The rub here is that, with a heart attack, every second counts. The sooner treatment is administered for this hard-to-diagnose event, the more likely a person is to survive. Levering miniaturized spectroscopy and laser light techniques, researchers at Johns Hopkins are trying to change that.
They have developed a new blood test that can diagnose heart attacks in minutes—rather than hours—that could eventually be adapted as a tool for first responders and even at-home use.
Current and future diagnostics
People suspected of having heart attacks are typically given a combination of tests to confirm the diagnosis. The first is usually electrocardiograms to measure the electrical activity of the heart, a procedure that takes about five minutes. Patients are also given blood tests to detect the hallmarks of a heart attack. This is where time is of the essence—lab work can take at least an hour and sometimes has to be repeated to confirm diagnosis.
Whereas, the proof-of-concept blood test by Peng Zheng and Ishan Barman can provide results in 5 to 7 minutes.
Zheng and Barman develop diagnostic tools using light to detect biomarkers, a technique called biophotonics. Here they used the biophotonics to find the earliest signs in the blood that someone is having a heart attack.
The heart of the invention is a tiny chip with a unique nanostructured surface on which blood is tested. The chip's “metasurface” enhances electric and magnetic signals during Raman spectroscopy analysis, making heart attack biomarkers visible in seconds—even in ultra-low concentrations. The tool is sensitive enough to flag heart attack biomarkers that might not be detected at all with current tests, or not detected until much later in an attack. In addition to being faster, it’s also more affordable than current methods, the researchers say.
Like a Tricorder
Though created for speedy diagnostic work in a clinical setting, the researchers say the blood test could be adapted as a handheld tool that first responders could use in the field, or even for people to use at home.
“We're talking about speed, we're talking about accuracy, and we're talking of the ability to perform measurements outside of a hospital,” said Barman, a bioengineer in JHU's Department of Mechanical Engineering. “In the future we hope this could be made into a hand-held instrument like a Star Trek tricorder, where you have a drop of blood and then, voilà, in a few seconds you have detection.”
The team also thinks the tool could be modified to detect infectious diseases and cancer biomarkers.
“There is enormous commercial potential,” said Barman. “There's nothing that limits this platform technology.”
Next, Zheng and Barman plan to refine the blood test and explore larger clinical trials.