Case Western Reserve University and the Case Medical Center researchers are working on improving treatment and survival rates of ischemic heart disease patients by enabling doctors to take an unprecedented look at the stents they place in coronary arteries. The research team recently received a $1.7 million grant from NIH’s National Heart, Lung and Blood Institute.
Hundreds of thousands of ischemic heart disease patients in the U.S are treated with stents annually. The disease blocks coronary arteries which reduces the flow of blood to the heart. Stents when inserted are able to hold open vessels to restore blood flow. Stents can also be treated with medicines that are released over time and hopefully prevent excessive formation of fibrous tissue and recurrent narrowing of the vessels.
While the treatment has improved over time, about five percent of stents fail in the first year following implant and an additional one percent fail every additional year due to recurrent narrowing of the artery or from blood clots that can form at the site. Such failure can be catastrophic causing heart attacks or sudden death.
To make decisions on the patient’s treatment, images are needed. Today’s, Optical Coherence Tomography (OCT) expert will sometimes take as many as 500 images of each stent. The images are actually reflections of an infrared laser in the artery measured at various depths to produce a three dimensional image. Currently, this process can take a trained doctor eight to 15 hours to do a complete analysis.
The NIH funding would enable researchers to develop software that would quantitatively analyze every detail captured within minutes and eliminate the variability of manual analysis. The new technology when developed should have ten times the resolution of the analogous ultrasound-based technology.
The rapid return of information would enable cardiologists when implanting stents to determine if more stents are needed during the procedure to seal off plaques likely to rupture, or to optimize stent deployment, or whether the device needs to be made wider to improve blood flow during the procedure.
If a stented patient complains of problems or doesn’t improve, by using the technology, the doctor would then be able to reexamine the patient during a follow-up visit to see if the stent scaffold is covered with new tissue as designed. The findings may be used to guide therapy in the case where medication would need to be prescribed to prevent blood clotting.
In addition to use in clinical practices, the technology could also be used to guide research development for new stent designs. Stents could also have different architectures, be metal or materials that are absorbed by the body, or perhaps coated to activate cell coverage and be able to hold or release a variety of drugs.