The case control study involved just over 27,000 patients in 52 countries and collected data on assessed the relationship between risk of acute MI and current or former smoking, type of tobacco used, amount smoked, effect of smokeless tobacco and passive smoking. Adjustments were made for differences in lifestyles between smokers and non-smokers.
The study found that current smokers were approximately 3 times as likely to experience an MI compared to non-smokers; the risk also increased by 5.6% for each additional cigarette smoked. [Odds Ratio 2.95 CI 2.77-3.14] This excess risk fell to 1.87 [CI 1.55-2.24] within 3 years of stopping smoking and to 1.22 [CI 1.09-1.37] after 20 years. Even after 20 years the remaining excess risk was statistically significant.
Action: All forms of tobacco usage should be strongly discouraged in order to prevent cardiovascular diseases.