Objective To analyze the correlation of serum small and dense low-density lipoprotein (sd-LDL), lipoprotein-associated phospholipase A2 (Lp-PLA2) and brain natriuretic peptide (BNP) with coronary artery stenosis degree and prognosis in elderly patients with coronary heart disease complicated with angina pectoris of different disease severities. Methods 86 elderly patients with coronary heart disease and angina pectoris admitted to the hospital from January 2020 to November 2021 were selected as observation group and were divided into low-risk subgroup (n=33), middle-risk subgroup (n=30) and high-risk subgroup (n=23) according to Gensini score. 30 healthy subjects with physical examination during the same period were enrolled as control group. The levels of serum sd-LDL, Lp-PLA2 and BNP were compared among the above groups at admission. Pearson correlation coefficient was used to analyze the relationship between Gensini score and serum levels of sd-LDL, Lp-PLA2 and BNP in observation group of patients with different disease severities. Patients in observation group were followed for 12 months, and the prognosis was recorded. Serum sd-LDL, Lp-PLA2 and BNP levels at admission were compared between good and poor prognosis subgroups. The predictive value of the above serological indicators on poor prognosis in elderly patients with coronary heart disease complicated with angina pectoris was analyzed by receiver operating characteristic curve (ROC).Results The levels of serum sd-LDL, Lp-PLA2 and BNP in observation group at admission were higher than those in control group (P＜0.05). Serum sd-LDL, Lp-PLA2 and BNP levels and Gensini score in the three groups were shown as high-risk subgroup＞middle-risk subgroup＞low-risk subgroup (P＜0.05). Pearson correlation coefficient analysis showed that serum BNP level in middle-risk subgroup was positively correlated with Gensini score (r=0.402, P＜0.001). Serum sd-LDL, Lp-PLA2 and BNP levels in high-risk subgroup were positively correlated with Gensini score (r=0.625, 0.431, 0.813, all P＜0.001). During follow-up, there were 73 cases of good prognosis and 13 cases of poor prognosis in observation group. Serum levels of sd-LDL, Lp-PLA2 and BNP at admission were higher in poor prognosis subgroup than those in good prognosis group at admission (P＜0.05). ROC curve results showed that the predictive efficiency of serum sd-LDL, Lp-PLA2 or BNP (AUC=0.748, 0.818, 0.781) on poor prognosis of elderly coronary heart disease with angina pectoris was lower than that of the combined diagnosis (AUC=0.913).Conclusion Serum levels of sd-LDL, Lp-PLA2 and BNP are closely related to the degree of coronary artery stenosis in elderly patients with coronary heart disease complicated with angina pectoris