- In a series of laboratory and animal studies, erectile dysfunction drug sildenafil showed promise in reducing blood clots and re-narrowing of arteries after stent placement.
- If confirmed in human trials, the drug might someday be included in the coating of stents or given orally just after a stent is inserted to open a narrowed artery.
PORTLAND, OREGON — A stent coated with an erectile dysfunction drug may someday help prevent arteries from becoming narrow or blocked again, according to preliminary research presented at the American Heart Association’s Basic Cardiovascular Sciences 2017 Scientific Sessions.
Stents help keep coronary arteries open and reduce the chance of a heart attack. With traditionally used bare metal stents, excessive tissue growth within the treated portion of the artery can cause restenosis — the artery to become narrow or blocked again. Drug-eluting stents coated with medications can help prevent this problem, but they are more subject to another complication – the development of a blood clot near the stent – which can happen soon after the placement procedure. Stent patients are routinely prescribed aspirin or other anti-platelet medications to help prevent clots.
In this series of studies, the drug sildenafil showed potential in reducing both restenosis and blood clot formation. Sildenafil, sold as the brand name Viagra among others, was originally developed as a medication for treating high blood pressure, and a side effect was the improvement of erectile dysfunction.
- In laboratory tests, sildenafil reduced clumping of blood platelets by 30 percent;
- In rats, sildenafil increased the activity of an enzyme (protein kinase G, or PKG) that helps prevent the thickening of artery walls when given after injury to an artery, mimicking what might happen after stent placement;
- Activating the PKG pathway is an important part of sildenafil’s action in preventing restenosis because the vessel injury such as stent implantation reduces PKG activity, increasing the thickening of artery walls and increasing the clumping of platelets.
“If similar results are found in clinical trials, sildenafil could be an ideal drug for coating drug-eluting stents or to give orally after stent implantation,” said lead study author Han-Mo Yang, M.D., Ph.D., an associate professor in the division of cardiology at Seoul National University Hospital. The enzyme PKG is highly expressed in arteries as well as in the erectile tissue of the penis, and sildenafil works in both.
“Our study is limited by involving only animals. If clinical trials show that sildenafil reduces restenosis after stent placement, it could be used in the clinical setting right away because the drug is already used in the real world for other purposes,” said Yang.
Co-authors are Sooryeonhwa Jin, B.S.; Sahmin Lee, M.D., Ph.D; and Hyo-Soo Kim, M.D., Ph.D.
Author disclosures are on the abstract.
Statements and conclusions of study authors that are presented at American Heart Association scientific meetings are solely those of the study authors and do not necessarily reflect association policy or position. The association makes no representation or warranty as to their accuracy or reliability. The association receives funding primarily from individuals; foundations and corporations (including pharmaceutical, device manufacturers and other companies) also make donations and fund specific association programs and events. The association has strict policies to prevent these relationships from influencing the science content. Revenues from pharmaceutical and device corporations and health insurance providers are available at www.heart.org/corporatefunding.
About the American Heart Association
The American Heart Association is devoted to saving people from heart disease and stroke – the two leading causes of death in the world. We team with millions of volunteers to fund innovative research, fight for stronger public health policies, and provide lifesaving tools and information to prevent and treat these diseases. The Dallas-based association is the nation’s oldest and largest voluntary organization dedicated to fighting heart disease and stroke. To learn more or to get involved, call 1-800-AHA-USA1, visit heart.org or call any of our offices around the country. Follow us on Facebook and Twitter.