Clot-Busting Therapy Under Review

ByABC News
September 28, 2009, 5:23 PM

Oct. 2 -- MONDAY, Sept. 28 (HealthDay News) -- Even as they digest the latest news on what dose of the clot-dissolving drug Plavix is best during angioplasty, cardiologists are looking at the next generation of clot-busters that could replace Plavix.

Clot-dissolving therapy was the big buzz among cardiologists at last week's Transcatheter Cardiovascular Therapeutics conference in San Francisco, according to Dr. Daniel I. Simon, a professor of cardiovascular research at Case Western Reserve University School of Medicine in Cleveland.

"What is the best dose of Plavix to be used in heart attacks?" Simon asked. "That is the number one question in cardiology."

But right behind that question is one about the role of two new antiplatelet agents -- prasugrel (Effient), which was approved by the U.S. Food and Drug Administration in July, and ticagrelor (Brilinta), which is expected to be submitted for FDA approval by the end of this year.

Trials have shown that both drugs can be more effective at keeping arteries open while reducing the risk of excess bleeding, which is the main hazard of Plavix (clopidogrel), Simon said.

But all clot-dissolving drugs carry the threat of excess bleeding. For example, the FDA requires prasugrel to carry a "black-box" warning on its label on the danger of excess bleeding.

"You have to balance the risk of bleeding, which is a safety issue, with efficacy, preventing heart attack and stroke," Simon said. "The more potent an antiplatelet agent you have, the more bleeding you might have. There are investigations that have been published showing that increasing the dose of clopidogrel can improve efficacy without more bleeding. We are trying to get to a sweet spot."

Platelets are the cells that clump together to form artery-blocking clots.

The latest of those trials, published in the Oct. 6 issue of the Journal of the American College of Cardiology, found that a 600-milligram dose of Plavix is more effective than a 300-milligram dose during angioplasty for people with the most severe form of heart attack.