Hossain, Hughes develop heart treatment

To help physicians use a new patient-customized heart treatment, ICES Professor Thomas Hughes and his mechanical engineering Ph.D. student Shaolie Hossain developed mathematical models to simulate it, and mobilized a team of students and faculty to produce an instructional video on how to use it.

To help physicians intricately customize heart disease treatment, ICES Professor Thomas Hughes and his former Ph.D. student Dr. Shaolie Hossain simulated a new treatment for the most common cause of heart attacks, and mobilized a team of students and faculty to produce an instructional video on how to use it.

“Navigating ‘the great divide’ that often exists between clinicians and engineers or scientists can be challenging,” Hossain said. “We hope this video will help bridge this gap, and prove to be educational to the general public.”

For her Ph.D. dissertation research, Hossain created a 3-D model of a heart drug delivery system that integrates MRI, CT-Scan, intravascular ultrasound, and a patient’s other physiological data.

Her model demonstrates a method to prevent and treat “vulnerable plaque,” the cause of two-thirds of all heart attacks. To encourage use of the new technology, Hossain, now an ICES visiting research scholar and a research associate at the Methodist Hospital Research Institute, marshaled university resources to make her work widely accessible on video.

The treatment represents a continuation of decades of work by Dr. Hughes and his students to develop effective patient-specific heart disease interventions. Cardiovascular disease is the leading cause of death in the United States and represents more than a half trillion dollar business in research and treatment here.

With the venerable Hughes as narrator, and another of Hughes’ Ph.D. students, Ben Urick, overseeing production, the video seeks to offer an integrity of content that should speed adoption of this new treatment.

“Both detection and treatment of vulnerable plaque represent huge unmet clinical needs,” says Hughes, professor of Aerospace Engineering and Engineering Mechanics, one of the most-cited authors in scientific computing.

Standard medical imaging tests such as MRIs, CT-Scans, external ultrasound, and coronary angiography, used separately, fail to detect vulnerable plaques.

But a new imaging technology has yielded promising results. Virtual Histology Intravascular Ultrasound (VH-IVUS) generates images of an artery cross section from an ultrasound catheter tracked through the vasculature. It can distinguish between low-risk artery wall thickening and a high-risk lesion.

Once identified, current drugs such as statins prevent about 30 percent of vulnerable plaque heart attacks or strokes. New studies propose supplementing statins with drugs delivered directly to diseased arteries to rapidly stabilize vulnerable plaques and prevent rupture.

Hossain’s models demonstrate how to use the VH-IVUS imagery to precisely deliver the supplemental drugs within each individual patient’s anatomy and physiology.

“The probability of a drug-encapsulated particle firmly adhering to the artery wall, depends on a patient’s specific physiological parameters,” says Hossain.

“Using this newly-available information from a patient’s VH-IVUS, we created models that showed the specific geometry of a patient’s arterial wall, as well as the fine junctures among arteries,” says Hossain. “This allows a physician to identify the location of the vulnerable plaque and inject a customized amount of the drug at a specific site tailored to the patient’s artery structure and blood flow features for the best outcome.”

Hughes and Hossain developed a computational toolset and simulation capabilities to model important characteristics of the research such as fluid flow, drug release, nanoparticle properties, and patient-specific geometries.

“Modeling these very complicated systems involves solving millions of equations each time step, and for millions of time steps, so the computational burden is enormous,” Hughes said. The researchers used the computational facilities at the Texas Advanced Computing Center's (TACC) to run their simulated experiments. In addition, TACC provided sophisticated visualization expertise and techniques, while technical artwork and video production equipment were provided by the Faculty Innovation Center of the Cockrell School of Engineering.

The 14-minute animation explains the nature of vulnerable plaques, and a potential treatment using a patient’s personal geometries to allow for precise delivery of the supplemental drugs.

Many visualizations and computer-generated animations exist to explain science results. “What seemed to be lacking was an explanation of the mathematical and computational modeling behind these videos and animations,” said Urick, Hughes’ student who works as a graduate research assistant in TACC’s Visualization Group. “We wanted to tell the whole story of the research from the background to the modeling to important results—all with the same level of aesthetic quality.”

Abbott Vascular, a California-based medical device company, where Hossain spent six months as a research intern was the initial sponsor of this work. The latter phase of the research was supported by Portugal CoLab.

The instructional video is widely available on YouTube.

Posted: Oct. 16, 2012