Men and women who discontinued smokeless tobacco after MI cut their mortality risk in about half compared with adults who did not stop using smokeless tobacco, according to a new report.
“We didn’t expect to see such a strong association among those people who stopped using [smokeless tobacco],” Gabriel Arefalk, MD, of Uppsala University Hospital, Sweden, said in a press release. “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.”
Arefalk and colleagues analyzed patients younger than 75 years who were admitted to coronary care units in Sweden for MI between 2005 and 2009. They compared post-MI mortality risk between those who stopped using snus, a moist Swedish smokeless powder tobacco, after MI (n=675) vs. those who did not stop using snus (n=1,799). Nicotine levels in snus are comparable to those in snuff, Arefalk said in the press release.
During a mean-follow-up of 2.1 years, 83 participants died, 69 of whom did not stop using snus, the researchers reported.
For those who quit snus after MI, the mortality rate was 9.7 per 1,000 person-years at risk (95% CI, 5.7-16.3); for those who did not quit, the mortality rate was 18.7 per 1,000 person-years at risk (95% CI, 14.8-23.6).
After adjustment for age and sex, men and women who quit snus after MI had approximately half the mortality risk compared with those who did not quit (HR=0.51; 95% CI, 0.29-0.91). The association remained after adjustment for past and present smoking and snus exposure (HR=0.55; 95% CI, 0.3-0.97); the point estimate remained about the same, but the confidence intervals got wider after adjustment for occupation status and participation in a cardiac rehabilitation program (HR=0.57; 95% CI, 0.32-1.02).
The mortality-related HRs associated with quitting snus after MI were similar to those associated with quitting smoking after MI, according to the researchers.
Compared with those who continued smoking after MI (n=2,675), men and women who quit smoking after MI (n=4,259) had approximately half the mortality risk after adjustment for age and sex (HR=0.5; 95% CI, 0.39-0.63), after further adjustment for past and present smoking and snus exposure (HR=0.5; 95% CI, 0.39-0.63) and after further adjustment for occupation status and participation in a cardiac rehabilitation program (HR=0.54; 95% CI, 0.42-0.69).
Disclosure: The study was funded by the Swedish Heart-Lung Foundation, the Swedish Research Council and the Swedish Geriatric Fund. The researchers report no relevant financial disclosures.