By Bill Zeeble, KERA 90.1 reporter
Dallas, TX – Bill Zeeble, KERA 90.1 reporter: Balloon angioplasty, where clogged arteries are widened surgically, is only about 25 years old in this country. Using tiny, mesh metal tube devices called stents to open blocked arteries is even newer, about 10 years old. Stents in choked arteries function like braces on weak cave walls. But there's a problem, according to Dallas cardiologist Manuel Cruz.
Dr. Manuel Cruz, Cardiologist: Restenosis, or scar tissue forming within blood vessels, or on stents, has been one of our major challenges in interventional cardiology.
Zeeble: Dr. Cruz says heart surgeons typically see restenosis in 30% of stent patients within six months of surgery. So they often undergo another stressful heart operation to repair the damage. Which is why Cruz says he was excited to hear about a drug that significantly reduces restenosis. In a controlled Korean study of about 100 patients with diabetes, the incidence of restenosis dropped nearly 40%. Patients received the insulin-sensitizing drug Rosiglitazone. Although it wasn't designed to reduce restenosis, Dr. Alex Cobitz, an endocrinologist with Glaxo Smith Kline, the drug's maker, theorizes its anti-inflammatory properties explain the result.
Dr. Alex Cobitz, Researcher, Glaxo Smith Kline: When you look at restenosis, you see smooth muscle cells moving into the area of the stent. Movement of smooth cells is caused by inflammation. So the anti-inflammatory effect of Rosiglitazone may be what is mediating this improvement of restonosis. Animal studies have shown similar effects.
Zeeble: Research fellow Sunghee Choi, who co-authored the independent Korean study, believes Rosiglitazone could carry broader implications.
Sunghee Choi, Research Fellow, Yonsei University College of Medicine, Seoul, Korea: So if Rosiglitazone blocks this kind of inflammatory process, it could be given to non-diabetic patients also.
Zeeble: But that's only if ongoing research proves it. For now, Dallas cardiologist Cruz is sticking to proven research, and prefers a stent that's only been in use about a month. It's coated with an antibiotic that cuts cell growth. Stop smooth cell growth on the stent, goes the thinking, and you'll stop restenosis.
Cruz: In trials, restenosis rates for these stents at 6 months was close to zero. We're actually talking zero vs. 30-40%. Now, after some more results it's roughly 5%, which is quite an advance.
Zeeble: For his diabetic patients needing stents, Cruz says he would now use drug- coated stents followed by Rosiglitazone. In the meantime, several companies are experimenting with different kinds of coated stents. Some stents are also radiated, to halt cell growth the way radiation stops cancer cell growth. Meanwhile, the maker of Rosiglitazone says the potential uses of that drug to improve cardiac patient health is just the beginning. For KERA 90.1, I'm Bill Zeeble.
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