FDA expects to toughen coated-stent guidelines.

FDA expects to issue new testing requirements in the next few weeks for drug-coated heart stents, the agency's device chief, Daniel Schultz, said Dec. 14, according to "The Wall Street Journal."

The revised guidelines come after some researchers have expressed fears that drug-coated stents may cause serious complications. FDA held a two-day meeting last December over concern that coated stents increase the risk of blood clots years after implantation. After a year of study, it still isn't clear whether they increase late clots, but coated stents don't appear to increase deaths or heart attacks when compared with plain stents.

Stents prop open clogged arteries to relieve chest pains from heart disease. Models coated with drugs to reduce reclogging, from Boston Scientific and Johnson & Johnson, account for most of the U.S. market.

The new FDA guidelines, which are expected to be more stringent than those currently in force, will probably cover items such as the numbers of patients on whom new stents must be tested and for how long. The rules may extend to the periods both before and after FDA approves a stent for sale to the public. The guidelines may also discuss the recommended time that patients should take the anti-clotting drug Plavix after getting a new stent.

FDA's bar for approval can affect how much companies spend on studies as well as the level of certainty doctors and patients can have that stents are safe and effective.

The guidelines aren't expected to affect stents already on the market or models from Minneapolis-based Medtronic and Abbott Laboratories that appear to be on the verge of approval.