Cocaine users face a newly discovered and possibly fatal risk: coronary aneurysms, a ballooning of the walls of coronary arteries. The condition increases the chance of suffering a heart attack, even years after users stop the drug, researchers in Minnesota are reporting. The risk of developing an aneurysm was four times as high among cocaine users in their mid-40's as among nonusers in the same age group, according to the study, reported yesterday in the journal Circulation, which is published by the American Heart Association. Aneurysms occurred in 30.4 percent of cocaine users in the study compared with 7.6 percent...