A 2011 study in the Journal of the American Medical Association found that only half of 144,000 nonemergency heart catheterizations—typically the use of tiny balloons and stents to clear blocked arteries—were appropriate; 38 percent were "uncertain" and 12 percent were "inappropriate." "It's presented in the media as if it's an aberrancy, when actually it's the rule," said Dr. David Brown, an interventional cardiologist and professor of medicine at SUNY-Stony Brook School of Medicine of the unnecessary heart procedures. "The medical system is addicted to the revenues that it generates." In 2011, Medicare alone spent nearly $1 billion on the procedures.