Heart Attacks Don't Stop Most Smokers By EMMA ROSS    MUNICH, Germany (AP) -- More than half of European smokers who suffer a heart attack, bypass surgery or other serious heart problem are still smoking a year later, despite anti-smoking campaigns and doctors' advice to stop, a new study found.    Experts said the findings, presented Monday at Europe's largest medical conference, indicate that smoking cessation efforts are failing many of the most vulnerable victims...