The computer assisted scan detects the amount of calcium in the heart.

From Correspondent Charles Feldman

LOS ANGELES (CNN) -- A heavily-promoted test measuring the amount of calcium present in the heart and coronary arteries has become one of the hottest and most divisive issues cardiology today.

The test is called EBCT -- electron beam computed tomography -- and popularly known as a "heart scan." Advocates of the procedure, also known as an ultra-fast CT, say it may be the best tool yet available to detect early coronary artery disease. About 50 medical centers across the United States offer the tests.

But some medical critics say the marketing of the scan directly to the general public has gone too far, with newspaper, television and radio advertisements featuring statements like "There's no doubt it saved my life."

"The electron beam CT scanner -- in a single breath -- gets a series of slices, pictures of the heart," said Dr. Daniel Berman of Cedars-Sinai Medical Center. "That gives us detailed definition of the amount of calcium that is within the heart or the great vessels of the coronary arteries."

The level of calcium found could offer a clue indicating the amount of atherosclerosis or hardening of the arteries, present. Higher amounts of calcium indicate a greater the risk of a heart attack, proponents of the procedure say.

The test is easy and non-invasive, and people with a zero calcium score usually find themselves relieved.

"I just wanted some peace of mind to feel like maybe my coronary vessels are in pretty good shape," said Jeff Purdy, who took the test recently.

But there are strong doubts about the procedure.

"There is no reason to believe there is a magic study or a magic scan which is going to assist in telling whether or not you are much more likely of having a heart attack than somebody else," said Dr. Robert Detrano, of Harbor-UCLA Medical Center.

EBCT has divided cardiologists across the United States. A committee of the American College of Cardiology will complete a statement on the heart scan soon -- a statement widely expected to be critical of the technology.

The U.S. Food And Drug Administration is looking into the marketing of the scan for what it calls the non-approved use as a heart screening test. And a recent article in the New England Journal of Medicine warns, "We are facing the possibility that market forces may increase interest in electron beam CT beyond what is justified by its potential medical benefit."

Despite the skeptics -- and most insurers' reluctance to pay for it -- demand for the heart scan is growing.

A million and a half Americans will have heart attacks this year alone--and 650 thousand will have had no previous indication of coronary artery disease.

"In my view, that indicates that there is a serious problem in respect to screening," said Lewis Meyer, CEO of ultra-fast CT manufacturer Imatron.

When calcium is detected, patients are usually told to more aggressively reduce known risk factors such as high blood pressure or cholesterol.

"I think that self-referral is probably a good idea. The reason is that what it allows us to do is define disease earlier than physicians normally would," Berman said.

Proponents of the heart scan say doctors who disapprove often don't know enough about the technology. But critics of the scan say once a hospital buys one, its doctors have a vested interest in using it. And with the equipment running about $1.5 million per unit, here is little doubt heart scans are big business.

One major manufacturer of a cholesterol-lowering drug recently gave a grant to a medical center to introduce doctors to the heart scan and give them a talk on the benefits of its drug.

But big business doesn't necessarily mean bad medicine. More and more university medical centers in the United States, and a growing number of leading cardiologists, have concluded the heart scan can be a life saver.