Experimental MRI may help detect heart trouble without the stress

A stress test can help detect heart disease before a heart attack occurs, but not everyone can do the required exercise or tolerate the alternative, a drug that increases blood flow to the heart. Now, German scientists have shown that an experimental type of MRI can spot trouble without the stress.

The MRI, called BOLD (blood oxygenation level-dependent), shows the amount of oxygen-depleted blood in the heart muscle. An area that’s dark indicates an increase in the amount of deoxygenated blood -- a sign that an artery is narrow or has become blocked.

Sixteen people with no history of heart disease had the experimental MRIs. Then 16 people known to have at least 70% narrowing in one coronary artery had several tests, including a stress test, an angiogram and the new MRIs, both at rest and after receiving a drug to stress the heart.

The images of the healthy hearts showed no dark areas, but images of hearts with blocked arteries revealed areas of deoxygenated blood both when the person was at rest and after the drug was given. The study was published in the March issue of the Journal of the American College of Cardiology.

“The surprising finding was that they could find a difference without giving a drug to induce stress,” says Dr. Francis J. Klocke, author of an editorial in the journal and director of the Feinberg Cardiovascular Research Institute at Northwestern University in Chicago.

-- Dianne Partie Lange