To investigate the correlation between small airway function and coronary heart disease (CHD) in the elderly patients.

A total of 180 patients with CHD confirmed by coronary angiography in Zhejiang Hospital from January 2020 to June 2021 were selected as the observation group, and 180 healthy controls who underwent physical examination during the same period were selected as the control group. Collected the relevant clinical data such as pulmonary ventilation function examination and laboratory examination of all subjects. T test/rank-sum test/Chi-square test were used for comparing the baseline data and pulmonary ventilation function indexes between the two groups, and then the statistically significant indexes were incorporated into the logistic regression model for multivariate analysis.

Compared with the control group, the observation group had a higher proportion of history of hypertension, white blood cell count, high density lipoprotein cholesterol, low density lipoprotein cholesterol, hypersensitive C reactive protein and total cholesterol (χ²=28.477; Z=3.673, 6.573, 6.782, 2.086; t=9.538; P < 0.05 or P < 0.01). Forced vital capacity (FVC), forced expiratory volume in the first second (FEV₁), FEV₁/FVC, maximum mid-expiratory flow maximal mid-expiratory flow (MMEF), forced expired flow at 50% of FVC and forced expired flow at 75% of FVC (FEF₇₅), in observation group were lower than those in control group (t=-5.244, -6.647, -3.247, -6.060, -5.636, -3.477, P < 0.01), and the proportion of small airway obstruction was higher than that in control group (χ²=19.897, P < 0.01). The results of Logistic regression analysis showed that MMEF and FEF₇₅ were significantly correlated with CHD in the elderly (OR=0.950, 1.021; 95%CI=0.911-0.990, 1.003-1.040; P < 0.05).

The decline of small airway function may contribute to the occurrence of CHD in the elderly.