A long-acting cholesterol medicine cut the risk of having a heart attack or some other serious problems by 15 to 20 percent in a big study that's likely to spur fresh debate about what drugs should cost. Statins such as Lipitor and Crestor are cheap and lower LDL or bad cholesterol, but some people can't tolerate or get enough help from them. The new drug, Amgen's Repatha, is given as a shot once or twice a month and is part of a novel class of medicines that drop LDL to unprecedented levels.