Smoking increases the risk of CHD. The long-term risk of smoking to individuals has been quantified in a 50-year cohort study of British doctors. The study found that mortality from CHD was around 60% higher in smokers (and 80% higher in heavy smokers) than in non-smokers. Observing deaths in smokers and non-smokers over a 50-year period, the study concluded “about half of all regular smokers will eventually be killed by their habit”.

Second hand smoke (smoke that has been exhaled by a smoker) is also harmful to cardiovascular health. Regular exposure to second hand smoke increases the risk of CHD by around 25%.

It is estimated that smoking caused about 31,000 deaths from CVD in 2000 in the UK. Overall, around one in eight deaths from CVD were attributable to smoking.  For men, the proportion of CVD deaths attributable to smoking fell between 1995 and 2000, from 16% to 13% in England and Wales, and from 22% to 18% in Scotland.  For women, the proportion of CVD deaths attributable to smoking fell by 1% between 1995 and 2000, from 12% to 11% in England and Wales, and from 19% to 18% in Scotland. A higher proportion of premature deaths from CVD, around one in five, were attributable to smoking.

Research from the World Health Organization has estimated the impact of smoking on total disease burden (both mortality and morbidity) in terms of disability-adjusted life years (DALYs) lost. The World Health Report 2002 estimated that in developed countries around 12% of all disease burden and over 20% of CVD was due to smoking.

More recently the INTERHEART case-control study estimated that 29% of heart attacks in Western Europe were due to smoking, and that smokers and former smokers were at almost twice the risk of a heart attack compared to never smokers.

A systematic review of the evidence on smoking cessation in patients with CHD concluded that, in this group, quitting smoking reduces the risk of dying by 36%.