Opening clogged arteries with balloon angioplasty saves many heart patients' lives, but the procedure has its own risks. During surgery, bits of the gunk blocking the blood vessel may break off and can cause heart attacks. Velocimed of Minneapolis, MN, is seeking U.S. Food and Drug Administration approval for a system that could reduce that danger. In the system, the artery-opening balloon is inflated upstream of the blockage, so even if gunk breaks off, there's no moving blood to carry it downstream. The trick is a tunnel through the balloon that lets doctors insert a "stent" that props the artery open and suck out any loose material with a syringe before they remove the balloon. With traditional angioplasty, up to 16.5 percent of patients suffer cardiac events such as heart attacks within 30 days of stent placement. But in a small European trial, Velocimed's system reduced that risk to about 5.6 percent.