Two years after a ban on smoking in bars and restaurants was enacted into law, a study by the North Carolina Division of Public Health in the USA shows a 21% decline in emergency room visits for heart attacks across the state.

http://www2.journalnow.com/news/2011/dec/02/1/public-smoking-ban-helping-lower-heart-attacks-off-ar-1672673/
http://www.wbtv.com/story/16037829/smoking-ban-may-have-cut-down-on-heart-attacks-in-nc