Discontinuation of Smokeless Tobacco and Mortality Risk after Myocardial Infarction
Background—Based on indications of increased risk for fatal myocardial infarction (MI) in snus users, we hypothesized that discontinuation of snus use after an MI reduces mortality risk.
Methods and Results—All patients who were admitted to coronary care units for an MI in Sweden between 2005 and 2009 and were under the age of 75 underwent a structured examination two months post-discharge (the baseline of the present study). We investigated risk of mortality in post-MI snus quitters (n=675) relative to post-MI continuous snus users (n=1799) using Cox proportional hazards analyses. During follow-up (mean 2.1 years), 83 participants died. The mortality rate in post-MI snus quitters was 9.7 (95% confidence interval 5.7 to 16.3)/1000 person-years-at-risk and in post-MI continuous snus users 18.7 (14.8 to 23.6)/1000 person-years-at-risk. Adjusting for age and gender, post-MI snus quitters had half the mortality risk of post-MI continuous snus users (hazard ratio 0.51; 95% CI 0.29 to 0.91). In a multivariable-adjusted model, the hazard ratio was 0.57 (95% CI 0.32 to 1.02). The corresponding estimate for post-MI smoke quitters vs. post-MI continuous smokers was 0.54 (95% CI 0.42 to 0.69).
Conclusions—In this study, discontinuation of snus use post-MI was associated with a nearly halved mortality risk, similar to the benefit associated with smoking cessation. These observations suggest that the use of snus post-MI should be discouraged.
- Received October 31, 2013.
- Revision received May 6, 2014.
- Accepted May 8, 2014.