Objective To investigate the impact of smoking cessation on high-resolution computed tomography (HRCT) phenotypes in smokers with chronic obstructive pulmonary disease (COPD) and its relationship with the frequency of acute exacerbations.

Methods A retrospective study was conducted in 237 smokers with COPD who could cooperate with a 1-year follow-up. Among them, 160 patients underwent a comprehensive 1-year smoking cessation intervention, and were divided into smoking cessation failure group (87 patients) and smoking cessation success group (73 patients) based on whether they successfully quited smoking. The remaining 77 smokers with COPD who did not receive smoking cessation intervention were designated as smoking group. HRCT phenotypes, total lung volume (TLV), total emphysema volume (TEV), emphysema index (EI) and the number of acute exacerbation at different time points were compared among the three groups. Pearson correlation analysis was used to explore the correlation between smoking cessation and the number of acute exacerbations.

Results There was no statistically significant difference in the proportion of A phenotype patients among the three groups before intervention and at 3 and 6 months of intervention (P>0.05). At the 9th and 12th months of intervention, the proportion of patients with A phenotype in the smoking group was lower than that in the smoking cessation failure group and smoking cessation success group (P < 0.05). Before the intervention and at the 3rd, 6th and 9th months of intervention, there were no statistically significant differences in the proportion of patients with E phenotype among the three groups (P>0.05). Before intervention and at the 3rd and 6th months of intervention, there were no statistically significant differences in the proportion of patients with M phenotype among the three groups (P>0.05). At the 9th and 12th months of intervention, the proportion of patients with M phenotype in the smoking group was higher than that in the smoking cessation failure group and smoking cessation success group (P < 0.05). Before intervention, there were no statistically significant differences in TLV, TEV and EI among the three groups (P>0.05). One year after the intervention, TLV, TEV and EI in the smoking cessation failure group and smoking cessation success group were lower than those in the smoking group (P < 0.05). At the 3rd, 6th, 9th and 12th months of intervention, the number of acute exacerbations in the the smoking cessation failure group and smoking cessation success group was less than that in the smoking group (P < 0.05). At the 9th and 12th months of intervention, the number of acute exacerbation in the smoking cessation success group was less than that in the smoking cessation failure group (P < 0.05). The results of Pearson correlation analysis showed that smoking cessation was negatively correlated with the number of acute exacerbation in smokers with COPD (P < 0.05), and this negative correlation gradually increased with the extension of smoking cessation duration.

Conclusion Smoking cessation can improve HRCT phenotypes and effectively reduce the number of acute exacerbation in smokers with COPD.