Quitting smoking could bring your risk of dying from a heart attack down to the same level as someone who's never smoked before, a new study suggests.
However, past smokers aren't totally out of the woods -- researchers found that they still are more likely to have blocked coronary arteries, which is considered a risk factor for heart attack.
The research was presented at the European Society of Cardiology Congress 2013.
"Our study was the first to demonstrate that the presence and severity of coronary blockages do not go away with quitting smoking, but that the risk of heart attack and death does," study researcher Dr. James K. Min said in a statement.
The study is based on data from 13,372 people from nine countries who were part of the Coronary CT Evaluation for Clinical Outcomes: An International Multicenter Study. Of those people, 2,853 were active smokers, 3,175 were past smokers, and 7,344 people had never smoked.
Researchers found that the probability of having a severe blockage or narrowing of one and two major heart arteries was 1.5 times higher in people who had smoked in the past or currently smoked. And the probability of having a severe blockage or narrowing in all three major heart arteries was two times higher in people who had smoked in the past or currently smoked.
However, the rate of heart attack or death from heart attack was the same among past smokers and never-smokers, with current smokers having a two-fold higher rate of heart attack or death from heart attack than never- or past-smokers.
But there are still a lot of questions that need to be answered about the findings, Min said. "For example, will the severe blockages observed in patients who have quit smoking provoke adverse events after two years (the duration of the present study)," he said in the statement. "Further, does the duration of smoking or the number of cigarettes smoked per day affect the severity of CAD or the prognosis related to quitting smoking. Our team and several others are pursuing such investigations."
A recent study in the New England Journal of Medicine gave more proof to the concept of quitting smoking as soon as possible -- it showed that stopping the habit before age 40 "gives back almost all of the decade of lost life from continued smoking," study researcher Dr. Prabhat Jha, a professor in the Dalla Lana School of Public Health at the University of Toronto, said in a statement.
"That’s not to say, however, that it is safe to smoke until you are 40 and then stop," Jha added in the statement. "Former smokers still have a greater risk of dying sooner than people who never smoked. But the risk is small compared to the huge risk for those who continue to smoke."
Indeed, another study presented at the same ESC Congress showed that even smokers who seem to live long lives still have shorter lifespans because of the habit. The research showed that even if you make it to age 70, you will still lose four years of life, on average, if you smoke.