Impact of Tobacco Smoking and Smoking Cessation on Cardiovascular Risk and Disease

Christopher Bullen

Disclosures

Expert Rev Cardiovasc Ther. 2008;6(6):883-895. 

In This Article

Benefits of Smoking Cessation

Smoking cessation almost completely reverses the risk of cardiovascular disease from smoking, making it potentially the single most effective and lifesaving intervention available for those at risk of and with existing cardiovascular disease.[10,86–90] Cessation rapidly reduces the risk of cardiovascular events including fatal events. A recent analysis of the Nurses' Health Study found that women who quit smoking experienced a rapid decline in the risk of death from coronary heart disease and stroke, with 61% of the benefit of cessation on coronary heart disease death and 42% of the benefit on stroke death realized within 5 years after stopping smoking.[91] Lightwood and Glantz demonstrated that the decline in RR for AMI and stroke after smoking cessation follows an exponential decay curve.[92] The curve flattens out within 4 years after quitting but the RR remains above 1.0 and is higher for stroke than for AMI.[92] This suggests that the benefits of cessation begin to be realized almost immediately a smoker quits,[10] as one might expect from the pathophysiological mechanisms at play. For example, within just 2 weeks of cessation by former long-term smokers, both fibrinogen concentration and the rate of fibrinogen synthesis are reduced.[93] There is reduced platelet volume[94] and platelet aggregability.[95] A significant reduction in white blood cells occurs[96] and a more favorable lipid profile begins to develop, with an increase in HDL, an increase in the HDL/LDL ratio, and a decrease in LDL.[96,97] Hemodynamic parameters also change in a favorable direction: significant reductions occur in mean arterial pressure, heart rate and arterial compliance.[98]

Cessation is especially effective for those with established cardiovascular disease. Benefits occur for all age groups and among patients with previous AMI and stroke and patients who have undergone revascularization procedures: a recent systematic review provided strong evidence that quitting smoking after AMI or cardiac surgery can decrease a person's risk of death by at least a third.[86] The beneficial impact of quitting smoking after serious heart disease may be as great or greater than other possible interventions and the risk reductions are consistent, regardless of differences between studies in index cardiac events – age, sex, country and time period.[86] The risk of sudden cardiac death also falls swiftly, within hours. The risk of AMI is significantly reduced within a few years of quitting.[10] Cessation also reduces arrhythmic death for patients with post-AMI left ventricular dysfunction[87] and significantly reduces the risk of recurrent cardiac arrest.[88]

Other vascular beds also benefit. Smokers with intermittent claudication who stop smoking demonstrate reductions in PVD progression. In a Swedish study that followed 343 patients with claudication over 7 years, rest pain developed in 26 patients, all of whom were current smokers, while none of the ex-smokers developed rest pain.[89] Compared with current smokers, male ex-smokers have a reduced risk of nonfatal stroke. Robbins et al. prospectively evaluated 22,071 male physicians in the Physicians' Health Study and, after adjusting for age and treatment assignment, found that physicians who were ex-smokers had a lower RR of total nonfatal stroke (RR: 1.2; 95% CI: 0.95–1.63) than physicians currently smoking less than 20 and more than 20 cigarettes daily, (RR: 2.0; 95% CI: 1.04–3.33 and RR: 2.5; 95% CI: 1.84–3.98 respectively.[90]

As noted earlier, the RR of cardiovascular events is much greater in younger versus older smokers, primarily because cardiovascular events are rare in young nonsmokers.[10] Although the RRs decline considerably with age, the absolute excess mortality caused by smoking rises progressively with age. Therefore, it is important for clinicians to promote smoking cessation even in elderly smokers.

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