A cohort study by Korean scientists showed that it may take more than 25 years to reduce the residual risk of developing cardiovascular disease in people with an eight-pack-year smoking history. For people with a shorter smoking history, this period was approximately ten years. The study was published in JAMA Network Open.
Smoking is the leading modifiable risk factor for cardiovascular disease, causing over eight million deaths worldwide each year. Thanks to smoking cessation counseling, nicotine replacement therapy, and medication, as well as increased cultural and social awareness, the smoking rate among adults has decreased from 32.7 percent in 2000 to 22.3 percent in 2020. However, the scientific literature is underrepresented in studies examining the temporal changes in cardiovascular disease risk after smoking cessation.
A research team led by Jun Hwan Cho of Chung-Ang University Hospital assessed the quantitative association between smoking cessation and subsequent cardiovascular disease risk depending on the duration of smoking and the time elapsed since quitting. To do this, the scientists analyzed a cohort of 5,391,231 participants. Overall, the incidence of cardiovascular disease was significantly higher among former and current smokers than among those who had never smoked.
Furthermore, compared with current smokers, former smokers with a smoking history of less than eight pack-years showed a significant reduction in the risk of developing cardiovascular disease within 10 years of quitting. However, for smokers with a smoking history of more than eight pack-years, the decline in the risk of developing cardiovascular disease was slower than for quitters with a short smoking history. The researchers estimated that the residual risk continued to decline for 25 years after quitting.
Based on the results of this study, the researchers propose that former heavy smokers with a smoking history of more than eight pack-years be treated similarly to current smokers in terms of cardiovascular disease risk assessment. Potentially, these patients require similar cardiovascular disease prevention and treatment methods as current smokers.
We previously reported that quitting smoking after being diagnosed with coronary heart disease almost halved the risk of developing a heart attack.
