In order to win the battle against heart disease, cardiologists found that they need a better way to identify plaque that is most likely to rupture and cause a heart attack. Angiography allows cardiologists to examine blood vessels for constricted regions by injecting them with a contrast agent before X-raying them. But plaque buildup. Intravascular ultrasound can penetrate the buildup to identify depth but cannot identify some of the finer details about the risk of plaque rupture.
Professor Laura Marcu’s lab in the Department of Biomedical Engineering at UC Davis has now combined intravascular ultrasound with fluorescence lifetime imaging (FLIm) in a single catheter probe that can image the tiny arteries of a living heart. The new catheter can simultaneously retrieve structural and biochemical information about the arterial plaque that could be predicting heart attacks better.
An optical fiber in the catheter sends short laser pulses into surrounding tissue, which fluoresces tiny flashes of light in return. Different kinds of tissue (collagen, proteins, and lipids) emit different amount fluorescence.
An ultrasound probe in the catheter records structural information about the blood vessel.
The combination FLIm-IVUS imaging catheter provides a comprehensive insight into how atherosclerotic plaque forms, aiding diagnosis and providing a way to measure how plaques shrink in response to therapy.
The new catheter has been tested in living swine hearts and samples of human coronary arteries.
The catheter used in this study is flexible enough to access coronary arteries in living humans following standard procedures. It doesn’t require any injected fluorescent tracers or any special modification of the catheterization procedures.
This new technique could not only improve understanding of mechanisms behind plaque rupture but also the diagnosis and treatment of patients with heart disease.
Marcu’s group is working to obtain FDA approval to test the new intravascular technology on human patients.
A paper on this study was published in Scientific Reports.