WASHINGTON (AP) — A medical implant that slowly dissolves into the body could be the answer to long-standing safety concerns with devices used to treat clogged arteries. The Food and Drug Administration approved the device Tuesday for patients with coronary artery disease, the artery-narrowing condition that causes about 370,000 U.S. deaths each year, according to government figures. Use of metallic stents surged in the early 2000s as a treatment for people who suffered a heart attack or experienced chest pain caused by clogged arteries that restrict blood flow. Studies in 2007 and 2008 suggested that stented arteries faced a higher risk of blood clots, potentially triggering heart attack a year or more down the road. Results of another five-year study showed that patients who received stents to treat chest pain fared about as well as those treated with drugs. More than a dozen medical device makers are working on their own dissolving stent technologies.