Smoking and ischaemic heart disease

• cigarette smoking approximately doubles the risk of morbidity and mortality from ischaemic heart disease compared with a lifetime of not smoking, and the risk is related to the duration and amount of smoking (1,2)
  
  
• all patients with ischaemic heart disease should be advised to stop smoking because it is a strong risk factor for a first myocardial infarction and for fatal and non-fatal recurrences
  • there is evidence (3) that in patients with coronary heart disease (CHD), smoking cessation reduces the risk of all cause mortality and non-fatal myocardial infarction
    
    
• the risk of morbidity and mortality associated with cigarette smoking falls immediately after stopping smoking, although it may be more than 20 years, if at all, before the risk associated with smoking is completely reversed (1,4)
• smokers are more likely to stop smoking after an acute coronary event - about 20% of patients will give up smoking after an acute myocardial infarction with a resultant 40% reduction in mortality rates and infarct recurrences (5,6)
  
  
• among men and women from diverse racial and ethnic groups, quitting smoking was associated with large reductions in the excess mortality associated with continued smoking (7)
  • all-cause mortality rate ratio (RR) for current vs never smoking was 2.80 overall
  • when comparing those who quit smoking before age 45 years with never smokers, all-cause mortality RRs were 1.15

Notes:

• for smokers under the age of 50 years the risk of developing coronary heart disease is 10 times greater than for non-smokers of the same age (8)
• passive smoking also increases the risk of CHD (9)

Reference:

1. Campbell NC et al.Secondary prevention in coronary heart disease: baseline survey of provision in general practice. BMJ 1998; 316: 1430-4.
2. Cook DG et al. Giving up smoking and the risk of heart attacks. A report from The British Regional Heart Study. Lancet 1986; 2: 1376-80.
3. Critchley JA, Capewell S. Mortality risk reduction associated with smoking cessation in patients with coronary heart disease: a systematic review. JAMA 2003;290:86-97.
4. Wald NJ, Watt HC. Prospective study of effect of switching from cigarettes to pipes or cigars on mortality from three smoking related diseases. BMJ 1997; 314:1860-3.
5. Jolly K et al for the SHIP Collaborative Group. Randomised controlled trial of follow up care in general practice of patients with myocardial infarction and angina: final results of the Southamptom heart integrated care project (SHIP). BMJ 1999; 318: 706-11.
6. Wilhelmsen L. Coronary heart disease: epidemiology of smoking and intervention studies of smoking. Am Heart J 1988; 115: 242-9.
7. Thomson B, Emberson J, Lacey B, et al. Association Between Smoking, Smoking Cessation, and Mortality by Race, Ethnicity, and Sex Among US Adults. JAMA Netw Open. 2022;5(10):e2231480. doi:10.1001/jamanetworkopen.2022.31480
8. British Heart Foundation (Factfile 8/2001). Stopping smoking - evidence-based guidance.
9. JBS2: Joint British Societies' guidelines on prevention of cardiovascular disease in clinical practice. Heart 2005; 91 (Supp 5).