Getting too little sleep -- or even too much -- appears to spell trouble for the heart. New data reveal that adults who get less than six hours of sleep a night are at significantly greater risk of stroke, heart attack and congestive heart failure. Even those who reportedly sleep more than eight hours a night have a higher prevalence of heart problems, namely chest pain (angina) and coronary artery disease, a narrowing of the blood vessels that supply blood and oxygen to the heart, according to research presented March 25 at the American College of Cardiology's 61st Annual Scientific Session. The Scientific Session, the premier cardiovascular medical meeting, brings cardiovascular professionals together to further advances in the field.