Physicians, researchers lead $1 million pilot trial to help patients with peripheral vascular disease

SAN ANTONIO (September 9, 2014) – A team of researchers and physicians at The University of Texas Health Science Center at San Antonio are leading a more than $1 million pilot trial to determine if drugs designed for heart attack survivors can benefit those suffering from life-threatening peripheral vascular disease.

The research will compare the clinical effects of two antiplatelet medications, ticagrelor and clopidogrel. Both are designed to prevent platelets from collecting, thereby blocking clots that can cause a heart attack or stroke. AstraZeneca, which markets ticagrelor, is funding the $1,081,847 study at three sites: the UT Health Science Center San Antonio, the University of Arkansas for Medical Sciences (UAMS) and the University of Alabama-Birmingham (UAB).

According to the American Heart Association, peripheral arterial disease affects about 8 million Americans. Because its main symptoms are cramping in the thighs or calves, many people mistake the symptoms for muscle or bone problems. The pain is actually the result of a blood-flow blockage due to plaque buildup.

Marc D. Feldman, M.D., professor of medicine and engineering in the Janey and Dolph Briscoe Division of Cardiology at the Health Science Center, said the San Antonio group in collaboration with the UAMS and the UAB developed the idea for the pilot research program and then went to AstraZeneca to seek funding.

Hinan Ahmed, M.D., and Anand Prasad, M.D., both cardiologists with UT Medicine San Antonio, will determine if patients they see who have lower limb claudication (pain caused by too little blood flow) and ischemia (inadequate blood supply to the lower limb due to blockage of blood vessels) meet the criteria to participate in the study.

UT Medicine San Antonio is the clinical practice of the School of Medicine at the UT Health Science Center San Antonio.
Patients also will be seen by cardiologists Mehmet Cilingiroglu, M.D., who did his fellowship in interventional cardiology at the Health Science Center and is now at UAMS, and by Massoud Leesar, M.D., of UAB.

A total of 40 patients at the three sites will have an initial catheterization, undergo a procedure to have a stent inserted, take part in one of two regimens of medicine, and undergo a second catheterization.

The patients will be divided into two randomly selected groups. One group will take ticagrelor and aspirin for six months. The second group will take clopidogrel and aspirin the first month, and then they will be on aspirin alone for months two through six.

The effect of the two medical therapies will be assessed by comparing blood clots seen by an imaging technique called Optical Coherence Tomography or OCT. The OCT imaging will be performed at the three sites and then sent to the core lab in San Antonio for analysis. The Health Science Center was one of the centers that assisted with the commercialization of this technique.

“OCT allows us to view the thickness and composition of arterial plaques,” Dr. Feldman said. “It enables us to see the clot as a three-dimensional image.”

With the OCT technology, it is possible to compare the effects of the two drug therapies after the six-month period, he said.

“In the future, we hope these patients can be put on a drug combination that reduces their likelihood of future blood clots. Our goal is to improve their quality of life and ultimately reduce the number of hospitalizations for acute limb ischemia and peripheral artery revascularization,” Dr. Feldman said.

This study involves a diverse team from the university: biomedical engineers Jennifer Phipps, Ph.D., and Taylor Hoyt; cardiologists Drs. Feldman, Ahmed and Prasad; research nurse Joan Drake, M.P.H., RN; and statistical and analytical assistance from the Department of Epidemiology and Biostatistics.


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