A tool that uses near-infrared light to identify high-risk arterial plaques can be used to identify patients at risk of heart attacks and strokes, according to a research carried out at WMG, University of Warwick, the Baker Institute and Monash University.

The researchers observed that when they increased the wavelength of the light currently used to visualize the atherosclerotic plaques, they could selectively identify the rupture-prone deposits, which commonly lead to blood clots, heart attacks, and strokes.

While some fatty deposits or plaques can remain stable for years, other high-risk cases develop complications, such as bleeding into the plaque, which leads to the formation of cracks and rupture of the fatty plaque. This can result in blockages in the blood vessels causing a heart attack or stroke. 

"What we have done uses innovative, materials-based techniques to assist in the development of new diagnostic tools," explained Dr. Tara Schiller, WMG, University of Warwick. "This could help us to detect the threat of an imminent heart attack and result in a decrease of the mortality rates," Dr. Schiller continues.

The researchers have discovered that increasing the wavelength of the infra-red (IR) radiation currently used to detect fatty deposit build-up in arteries to near-infrared (NIR) wavelengths allowed them to selectively identify plaques with internal bleeding, typically associated with high-risk deposits.

The products causing this fluorescence were identified using Raman spectroscopy. These products were only observed in the unstable plaques with internal bleeding. This can improve selectivity when looking for high-risk deposits in patients and could help doctors to identify the most at-risk patients.

"We realized when we shine a light in the near-infrared wavelength range, that this light is reflected at a certain wavelength. So in a way, we can use laser light to shine up the plaques that are unstable, and it's very characteristic," explained Dr. Karlheinz Peter.

After further investigation with clinical trials, this method of imaging technique could be used to assess unstable fatty arterial plaques and could be used to monitor the effectiveness of the drugs used to prevent heart attacks or strokes.