Predicting Success of Coronary Artery Surgery.

• Position: Brief Article

An advance in magnetic resonance imaging (MRI) developed by researchers at Northwestern University Medical School, Chicago, and Siemens Medical Systems has radically improved the ability to determine which patients with coronary artery disease will benefit from bypass surgery or angioplasty. The investigators, led by Northwestern cardiologist Raymond J. Kim and basic scientist Robert M. Judd, used an improved version of a technique known as contrast-enhanced MRI in 50 patients with heart disease who were scheduled to have bypass surgery or coronary angioplasty.

The procedure boosted image intensity tenfold over previous methods and enabled the researchers--without stress testing or use of radioactive tracers--to distinguish between reversible and irreversible heart injury. Kim and Judd explain that, with this technique, heart regions damaged by heart attack or other coronary artery disease appear on the MRI as hyperenhanced, or "bright." The researchers found that areas of the heart that were "dark" on the MRI recovered following bypass surgery or angioplasty, whereas "bright" areas did not.

The research group--which consisted of cardiologists, basic scientists, and physicists--reports that contrast-enhanced MRI is the first technique to allow physicians to view the extent of damage within the heart wall following a heart attack. The wall of the heart is approximately 10 millimeters thick. (A...