Tobacco use, especially cigarette smoking, has been well established as a CV risk factor since the Report of the Advisory Committee to the Surgeon General of the United States in 1964.30
Multiple epidemiological studies have shown that cigarette smoking is a major risk factor for CV events.31,32
The occurrence of significantly increased deaths of a CV etiology associated with cigarette smoking is worldwide such as that shown in India.33
Multiple studies through the years have shown that chronic cigarette smokers are at increased risk for sudden death and MI.34,35
Also, compared with nonsmokers who have never smoked, pipe and cigar smokers have also been shown to have a significantly increased risk for major CHD events and stroke events.36
In addition, evidence has continued to accumulate that passive secondhand smoke carries significant risk for CHD, such as a relative risk of CHD for active smokers at 1.78% compared with 1.31% for passive smokers.37
In addition, it has been shown that many important responses of the CV system, such as platelet activation, endothelial dysfunction, inflammation, atherosclerotic plaque instability, increased oxidized LDL, and increased oxidative stress, are very sensitive to toxins in tobacco smoke, whether secondhand or involving the primary smoker. Such mechanisms, rather than an isolated response, interact and compound the risk of CHD. To further extend the relevance of avoiding secondhand smoke, there is now widespread proof of decreased CHD events throughout the world since the advent of smoking bans, including significantly decreased acute coronary events in Italy38
and significantly decreased AMI admissions in Helena, Montana.39
Therefore, there is no doubt that a major factor in atherosclerosis prevention has been established for cigarette smoking cessation as well as for pipe/cigar smoking and also the avoidance of secondhand smoke.
It should be noted that there is an even more specific association of cigarette smoking and PVD than there is with CHD. In the Edinburgh Artery Study involving 1592 subjects (age range, 55 to 74 years) selected at random from age–sex registers from 10 general practices in Edinburgh, Scotland, the effects of cigarette smoking on CHD and PVD were compared.40
By logistic regression, adjusting for a various individual risk factors, it was found that there was no significant impact on the effect of smoking. The investigators found that the age and sex adjusted odds ratios were very significant for PVD but not for CHD. It was concluded that the stronger association between cigarette abuse and PVD as compared with CHD does not appear to be associated with other risk factors as examined and some other mechanism must be found to explain the increased association with PVD.
Cessation of cigarette smoking is associated with a substantial reduction in risk of all-cause mortality among patients with CHD and this reduction appears consistent across age, sex, index cardiac event, country, and year of study commencement in a systematic review by Critchley and Capewell.41
Similar benefit for PVD patients was found by Jonason and Bergström who studied the effect of smoking cessation in intermittent claudication patients.42
In 343 patients with intermittent claudication and involving male and female patients, 1 year after the initial evaluation, 39 (11%) had stopped smoking and 304 (89%) continued to smoke. Rest pain did not develop in any of the nonsmokers but in smokers the cumulative proportion with rest pain was 16% after 7 years (p
value less than 0.05). The cumulative proportions with MIs after 10 years were 11 and 53% in nonsmokers versus continued smokers, and the cumulative rates of cardiac deaths was 6 and 43%, respectively. The 10-year survival was 82 and 46% among nonsmokers and smokers. At 1 year follow-up, the association between smoking and mortality was significant (p
0.05). McRobbie and Thornley evaluated the importance of treating dependence on tobacco and commented on the important long-term benefits of smoking cessation.43
It appears that the risk of AMI is cut in half within a few years of smoking cessation and that patients with preexisting CHD have an even more rapid risk reduction. The authors also commented on a resultant reduced risk of nonfatal stroke and decreased PVD progression. Therefore, there appears to be essentially no doubt of the benefit of smoking cessation for the CHD and PVD patient regardless of sex and age.