Smoking ban in public areas is associated with a reduced incidence of hospital admissions due to ST-elevation myocardial infarctions in non-smokers. Results from the Bremen STEMI Registry

Introduction: Laws banning tobacco smoking from public areas have been passed in several countries, including the region of Bremen, Germany at the end of 2007. The present study analyses the incidence of hospital admissions due to ST-elevation myocardial infarctions (STEMIs) before and after such a smoking ban was implemented, focusing on differences between smokers and non-smokers. In this respect, data of the Bremen STEMI Registry (BSR) give a complete epidemiological overview of a region in northwest Germany with approximately 800,000 inhabitants since all STEMIs are admitted to one central heart centre.

Methods and results: Between January 2006 and December 2010, data from the BSR was analysed focusing on date of admission, age, gender, and prior nicotine consumption. A total of 3545 patients with STEMI were admitted in the Bremen Heart Centre during this time period. Comparing 2006-2007 vs. 2008-2010, hence before and after the smoking ban, a 16% decrease of the number of STEMIs was observed: from a mean of 65 STEMI/month in 2006-2007 to 55/month in 2008-2010 (p < 0.01). The group of smokers showed a constant number of STEMIs: 25/month in 2006-2007 to 26/month in 2008-2010 (+4%, p = 0.8). However, in non-smokers, a significant reduction of STEMIs over time was found: 39/month in 2006-2007 to 29/month in 2008-2010 (-26%, p < 0.01). The decline of STEMIs in non-smokers was consistently observed in all age groups and both sexes. Adjusting for potentially confounding factors like hypertension, obesity, and diabetes mellitus did not explain the observed decline.

Conclusions: In the BSR, a significant decline of hospital admissions due to STEMIs in non-smokers was observed after the smoking ban in public areas came into force. No reduction of STEMI-related admissions was found in smokers. These results may be explained by the protection of non-smokers from passive smoking and the absence of such an effect in smokers by the dominant effect of active smoking.