Doctors started opening blocked coronary arteries with balloon-tipped catheters in the 1970s, but repeat narrowing of those vessels sent many patients back to the hospital. In the 1980s, scientists devised mesh cylinders called stents that prop open the arteries after the balloon is withdrawn. Even with stents, however, one-fourth of reopened vessels become obstructed again within 6 months.
Researchers now report that stents coated with a drug that inhibits cell migration and growth sharply reduce blockages in repaired arteries. The report appears in the Oct. 2 New England Journal of Medicine.
Inserting a balloon into an artery, inflating the balloon, and installing a stent traumatize the inner reaches of a blood vessel. The trauma stimulates the body's tissue-repair system to send muscle cells to the site, where they then proliferate. The stent-coating drug, called sirolimus or rapamycin, discourages both these actions, says study coauthor Jeffrey W. Moses of