Researchers analyzed 12,152 men and women who participated in an international study based on their smoking status: current smokers, former smokers and nonsmokers.

Current smokers more than doubled their risk of death from heart disease and cancer and all causes in the three-year study period. Current smokers also were at increased risk of heart attack and stroke compared to former smokers and nonsmokers.

“The analysis provides further strong evidence that people with heart disease who continue to smoke take a very high risk of increasing their chances of death in the short term,” said Deepak L. Bhatt, M.D., M.P.H., principal investigator of Clopidogrel for High Atherothrombotic Risk and Ischemic Stabilization, Management and Avoidance (the CHARISMA trial) and chief of cardiology at V.A. Boston Healthcare System in Massachusetts.

“The study provides impetus for a smoker to stop,” he said. “The benefits of risk reduction accrue relatively quickly when someone stops smoking, although the lingering cancer risk is still there.”

Of the study participants, about 20 percent were current smokers; about 51 percent were former smokers; and about 29 percent never smoked. The average age ranged from 60 years in the smoking group to 66 years in the group of nonsmokers. All groups were predominantly Caucasian and included Americans and Europeans.

Researchers found no difference in risk between men and women by smoking status. Researchers also found no significant difference between former smokers and nonsmokers in risk of death from heart disease or from all causes. However, former smokers had a higher risk of death from cancer than those who never smoked.

Current smokers had a 2.58 times increased risk of death from all causes and a 2.26 times increased risk of death from heart disease compared with those who never smoked. They had a 3.56 times increased risk of cancer death.

“You’re much better off being a former smoker than a current smoker,” Bhatt said. “It’s a good idea to stop now rather than taking your chances or considering stopping when you are older and sicker.”

In another aspect of the study, researchers examined the impact of smoking on the treatment effect of the widely used medication clopidogrel, an anti-platelet agent.

The medication benefits smokers more than former smokers and nonsmokers, researchers said. Clopidogrel significantly reduced death from all causes and death from heart disease in current smokers. The benefit was less in former smokers and nonsmokers. While clopidogrel therapy was more effective in current smokers they also had a greater risk of bleeding compared to those who did not smoke.

Provided by American Heart Association