Scarring in the heart’s wall may be a key risk factor for death, and scans that calculate the amount of scarring might help in deciding which patients need particular treatments, a new study suggests. At issue is a kind of scarring, or fibrosis, known as midwall fibrosis. Reporting in the March 6 issue of the Journal of the American Medical Association, researchers found that patients with enlarged hearts who had more of this type of damage were more than five times more likely to experience sudden cardiac death compared to patients without such scarring.