People who quit using smokeless tobacco after a heart attack live longer, a new study finds.

The benefits of quitting smokeless tobacco after a heart attack were similar to quitting smoking altogether, researchers from Uppsala University found in the study.

"We didn't expect to see such a strong association among those people who stopped using (smokeless tobacco)," said Gabriel Arefalk, M.D., lead researcher and cardiologist at Uppsala University in a press statement. "After a heart attack, no doubt smoking cessation reduces the risk of death approximately one third and is really a cornerstone of cardiac rehabilitation worldwide. For smokeless tobacco, we did not know."

This is one of the first studies to look into the link between smoking smokeless cigarettes after a heart attack and longevity. Snus is a moist Swedish smokeless powder tobacco kept under the upper lip. It is very popular. For the study, researchers reviewed data on heart attack survivors younger than 75 in Sweden in 2005-09 and identified 2,474 snus users. Of these, 675 quit using snus. 

All participants were followed for two years. During this time, 14 snus-quitters died and 69 of those who continued using snus also died. Researchers using a mathematical model calculated that  the death rate was 9.7 per 1,000 person-years for snus quitters and 18.7 for snus users.

Influencing factors like age, gender, other tobacco use, occupation and participation in a cardiac rehabilitation program were taken into consideration. Swedish snus is known to contain more nicotine than most other forms of smokeless tobacco, and advocates say it is the only high-nicotine product on the market that can compete with cigarettes.

The study was published online in the American Heart Association journal Circulation. Researchers received funding from the Swedish Heart-Lung Foundation, Swedish Research Council and Swedish Geriatric Fund.