Streeter earns AHA grant for “innovative” idea

Jennifer Streeter, MD, PhD, associate of Internal Medicine-Cardiovascular Medicine, has received a two-year, $200,000 American Heart Association (AHA) Innovative Project Award, for her study, “Radiopaque Aptamer Dimers as Next Generation Contrast Agents.”

The idea for this project arose from Streeter’s work in the cardiac catheterization lab performing coronary angiography. To diagnose and treat patients with blocked heart arteries, cardiologists perform coronary angiography to quickly find and open blocked heart arteries by injecting them with a contrast agent and visualizing the arteries with X-ray fluoroscopy. Multiple injections are needed throughout this procedure because the contrast agents disappear within seconds. This increases the amount of contrast agent needed and adds to procedure time as well as extended X-ray exposure. A number of complications can also arise, including contrast-induced toxicity to the heart and kidneys, abnormal heart rhythms, heart attack, and stroke. Despite the known complications of current contrast agents, cardiologists continue using these agents because they are essential to coronary angiography and there are no alternatives.

Streeter, however, believes that biomolecules may offer a solution to the many shortcomings of contrast agents. She and her team will infuse aptamer libraries (large groups of short, unique RNA sequences) into the coronary arteries of explanted human hearts (discarded hearts from heart transplant recipients) and identify which aptamers bind specifically to these heart arteries. Coronary artery aptamers will be attached to a contrast agent to create radiopaque aptamer dimers (RADs). Streeter’s hypothesis is that RADs will specifically bind to coronary arteries and remain bound and visible throughout a coronary angiogram after a single injection. This will decrease contrast load and procedure time, thereby decreasing contrast-induced and procedure-related complications.

“This study will take the first crucial steps,” Streeter said, “toward engineering a new class of contrast agent with the goal of improving cardiovascular outcomes for patients undergoing coronary angiography.”

Streeter also said that she is “deeply grateful” for the “inspiration, guidance, and support” she received from her “exceptional scientific role models” and collaborators, William Thiel, PhD, and Isabella Grumbach, MD, PhD.

Leave a Reply