It's clear that measures to control risk factors such as high blood pressure and obesity should be stricter in people with more severe heart disease, Gerber said. "Nobody knows if making those measures even more strict would make the outcome better," he said. "That stands to reason, but we just don't know. No one has shown how making decisions based on calcium content influences outcome. The studies to tell us how to use that information to decrease risk haven't been done yet."
The why and how of calcium scans are explained by the U.S. National Heart, Lung, and Blood Institute.
SOURCES: Marcus Hacker, M.D., associate professor, nuclear medicine, Ludwig Maximilians University, Munich, Germany; Thomas G. Gerber, M.D., associate professor, medicine and radiology, Mayo Clinic, Rochester, Minn.; July 28, 2009, Radiology, online